阅读说明：本技术 电机的驱动控制装置和电机的驱动控制方法 (Motor drive control device and motor drive control method ) 是由 山本胜则 加藤博之 于 2019-01-08 设计创作，主要内容包括：实施方式的电机的驱动控制装置(1)具备：相间短路部(40),与3相线圈(Lu、Lv、Lw)中的至少2相线圈连接,对应于短路信号将3相线圈(Lu、Lv、Lw)中的2个线圈的组合相互不同的3组中的至少1组的线圈间短路；短路信号输出部(50),连接在线圈(Lw)与相间短路部(40)之间,若被输入制动控制信号则向相间短路部(40)输出短路信号；以及保护动作部(60),基于3相线圈(Lu、Lv、Lw)中的1相线圈(Lw)的电压的状态,解除基于相间短路部(40)的短路。(A drive control device (1) for a motor according to an embodiment is provided with: an interphase short-circuiting unit (40) which is connected to at least 2 of the 3-phase coils (Lu, Lv, Lw) and which, in response to a short-circuit signal, short-circuits at least 1 of 3 groups in which combinations of 2 of the 3-phase coils (Lu, Lv, Lw) are different from each other; a short-circuit signal output unit (50) that is connected between the coil (Lw) and the interphase short-circuit unit (40), and that outputs a short-circuit signal to the interphase short-circuit unit (40) when a brake control signal is input; and a protection operation unit (60) that releases the short circuit by the interphase short-circuit unit (40) based on the state of the voltage of the 1-phase coil (Lw) of the 3-phase coils (Lu, Lv, Lw).)

1. A drive control device for a motor includes:

a motor driving part selectively electrifying the 3-phase coil of the motor;

a motor control unit that switches an energization phase of the 3-phase coil energized by the motor drive unit in a predetermined order by outputting a drive control signal to the motor drive unit;

a brake control unit that outputs a brake control signal;

an interphase short-circuiting unit connected to at least 2 of the 3-phase coils and configured to short-circuit the inter-coil of at least 1 of the 3 groups having different combinations of 2 of the 3-phase coils in response to a short-circuit signal;

a short-circuit signal output unit connected between the inter-phase short-circuit unit and a 1-phase coil of the 3-phase coils, and configured to output the short-circuit signal to the inter-phase short-circuit unit when the brake control signal is input; and

and a protection operation unit configured to cancel the short circuit or suppress a short-circuit current by the interphase short-circuit unit based on a state of a voltage of a 1-phase coil out of the 3-phase coils.

2. The drive control device of an electric motor according to claim 1,

the protection operation unit stops the output of the brake control signal from the brake control unit based on the state of the voltage of the 1-phase coil out of the 3-phase coils.

3. The drive control device of an electric motor according to claim 2,

the protection operation unit includes:

a start time setting unit that outputs a voltage corresponding to a duration and a magnitude of a counter electromotive force generated by a 1-phase coil of the 3-phase coils;

a protection operation starting unit that outputs a start signal when the voltage output from the start time setting unit is equal to or higher than a preset voltage; and

and a brake release command unit configured to output a brake release command to the brake control unit to stop output of the brake control signal when the activation signal is output from the protection operation activation unit.

4. The drive control device of an electric motor according to claim 1,

the protection operation unit reduces a current flowing between the at least 2-phase coil and the interphase short-circuiting unit based on a state of a voltage of a 1-phase coil of the 3-phase coils.

5. The drive control device for the motor according to claim 4, comprising:

a braking force switching unit connected between the at least 2-phase coil and the interphase short-circuit unit, and configured to reduce the current;

a counter electromotive force level monitoring unit that outputs a voltage corresponding to the magnitude of a counter electromotive force generated by a 1-phase coil of the 3-phase coils;

a protection operation starting unit that outputs a start signal when the voltage output from the back electromotive force level monitoring unit is equal to or higher than a predetermined voltage; and

and a braking force change command unit configured to output a braking force change command to the brake control unit to cause the braking force switching unit to reduce the current when the activation signal is output from the protection operation activation unit.

6. A method for controlling the drive of an electric motor,

selectively electrifying the 3-phase coil of the motor through the motor driving part,

a motor control unit for outputting a drive control signal to the motor drive unit to switch the energization phases of the 3-phase coils energized by the motor drive unit in a predetermined order,

the brake control part outputs a brake control signal,

at least 1 of 3 groups of coils having different combinations of 2 coils among the 3-phase coils are short-circuited between the coils in accordance with a short-circuit signal by an interphase short-circuit section connected to at least 2 coils among the 3-phase coils,

a short-circuit signal output unit connected between the phase-1 coil of the phase-3 coils and the interphase short-circuit unit, the short-circuit signal being output to the interphase short-circuit unit when the brake control signal is input,

and a protection operation unit configured to cancel the short circuit or suppress a short-circuit current by the interphase short-circuit unit based on a state of a voltage of a 1-phase coil out of the 3-phase coils.

Technical Field

The present invention relates to a motor drive control device and a motor drive control method.

Background

Conventionally, the following techniques are generally used: when the three-phase brushless motor is operated for a fan motor, for example, the transaxle circuit is electrically short-circuited after receiving a rotation stop command or until the rotation is stopped after stopping the power supply, thereby short-circuiting the motor coils. In this way, by short-circuiting the motor coils, the counter electromotive force generated by the motor coils is short-circuited, and the rotation of the motor can be rapidly stopped by regenerative braking.

In this case, in order to short-circuit the motor coils, a power supply for operating the short-circuited system is required. Therefore, for example, in the braking operation when the power supply is turned off, the braking time is controlled by the amount of residual charge in the power supply line. In addition, the rotation suppression at the time of the occurrence of the phenomenon of the air mill (forced rotation of the blade by the outside wind) at the time of no power supply becomes a state of insufficient function.

To solve the above problems, the following braking device is known: after the power supply is stopped, the braking state is secured, and the motor is stopped slightly earlier.

As a braking device for an electric motor, for example, there is a braking device in which a short-circuit for forcibly stopping the electric motor by power generation braking is provided in a power supply path of the electric motor (for example, see patent document 1). The short circuit in the device is provided with a static induction type transistor which is turned on in a no-voltage state and short-circuits the short circuit.

As another braking device, for example, there is a dynamic braking device of a motor as follows (for example, see patent document 2): a motor drive circuit for driving and controlling a motor by a switching element is provided with a rectifier circuit and an energy consumption unit connected to the rectifier circuit. In this device, the rectifier circuit rectifies the counter electromotive force generated in the power line of the motor when the switching element is turned off, and the energy consuming unit consumes the counter electromotive force rectified by the rectifier circuit, thereby stopping the motor.

There is also a power supply interruption control circuit for an electric motor including a rectifier circuit and a switching circuit connected to an electromagnetic coil of the electric motor (see, for example, patent document 3). The switching circuit of the power supply interruption control circuit forms a closed circuit together with the electromagnetic coil and the rectifying circuit, and is not turned on when power is supplied to the electric motor and is turned on when power supply is interrupted.

Patent document 1: japanese laid-open patent publication No. 1-133583

Patent document 2: japanese laid-open patent publication No. 1-209973

Patent document 3: japanese laid-open patent publication No. 2010-28997

However, in the conventional regenerative braking described above, the load on the electronic components that perform the regenerative braking function is increased when external force is applied to the motor for a long time or when external force is large in a state where power is not supplied to the motor.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide a motor drive control device and a motor drive control method that reduce the load on electronic components that perform a regenerative braking function when the load on the motor increases in a state where power is not supplied to the motor.

In order to solve the above problems and achieve the object, a drive control device for a motor according to an aspect of the present invention includes: a motor driving part selectively electrifying the 3-phase coil of the motor; a motor control unit that switches an energization phase of the 3-phase coil energized by the motor drive unit in a predetermined order by outputting a drive control signal to the motor drive unit; a brake control unit that outputs a brake control signal; an interphase short-circuiting unit connected to at least 2 of the 3-phase coils and configured to short-circuit the inter-coil of at least 1 of the 3 groups having different combinations of 2 of the 3-phase coils in response to a short-circuit signal; a short-circuit signal output unit connected between the inter-phase short-circuit unit and a 1-phase coil of the 3-phase coils, and configured to output the short-circuit signal to the inter-phase short-circuit unit when the brake control signal is input; and a protection operation unit configured to cancel the short circuit or suppress a short-circuit current by the interphase short-circuit unit based on a state of a voltage of a 1-phase coil out of the 3-phase coils.

According to one embodiment of the present invention, when the load on the motor is increased without supplying power to the motor, the load on the electronic component that performs the regenerative braking function can be reduced.

Drawings

Fig. 1 is a block diagram (1) showing an example of a circuit configuration of a motor drive control device according to embodiment 1.

Fig. 2 is a block diagram (2) showing an example of the circuit configuration of the motor drive control device according to embodiment 1.

Fig. 3 is a diagram illustrating an operation mode of the motor drive control device according to embodiment 1.

Fig. 4 is a flowchart illustrating an example of the operation procedure of the protection operation unit of the motor drive control device according to embodiment 1.

Fig. 5 is a diagram for explaining an example of the effect of the protective operation of the motor drive control device according to embodiment 1.

Fig. 6 is a view (1) showing a modification of the interphase short-circuiting portion according to embodiment 1.

Fig. 7 is a view (2) showing a modification of the interphase short-circuiting portion according to embodiment 1.

Fig. 8 is a block diagram (1) showing an example of the circuit configuration of the motor drive control device according to embodiment 2.

Fig. 9 is a block diagram (2) showing an example of the circuit configuration of the motor drive control device according to embodiment 2.

Fig. 10 is a flowchart illustrating an example of the operation procedure of the protection operation unit of the motor drive control device according to embodiment 2.

Fig. 11 is a diagram (1) showing a modification of the protection operating unit and the inter-phase short circuit unit according to embodiment 2.

Fig. 12 is a diagram (2) showing a modification of the protection operating unit and the inter-phase short circuit unit according to embodiment 2.

Detailed Description

Hereinafter, a motor drive control device and a motor drive control method according to an embodiment will be described with reference to the drawings.

(embodiment 1)

Fig. 1 is a block diagram showing an example of a circuit configuration of a motor drive control device according to embodiment 1.

As shown in fig. 1, the motor drive control device 1 according to embodiment 1 includes a motor drive unit 10, a motor control unit 20, a brake control unit 30, an inter-phase short circuit unit 40, a short circuit signal output unit 50, and a protection operation unit 60. Note that the components of the motor drive control device 1 shown in fig. 1 are a part of the whole, and the motor drive control device 1 may include other components in addition to the components shown in fig. 1.

The motor drive control device 1 may be an integrated circuit device (IC) in which all of the device is packaged, or a part of the motor drive control device 1 may be packaged as one integrated circuit device, or all or a part of the motor drive control device 1 may be packaged together with other devices to form one integrated circuit device.

The motor drive unit 10 selectively energizes the 3-phase coils Lu, Lv, Lw of the motor 3. The motor control unit 20 outputs a drive control signal to the motor drive unit 10, thereby switching the energization phases of the 3-phase coils Lu, Lv, and Lw energized by the motor drive unit 10 in a predetermined order.

Further, the brake control unit 30 outputs a brake control signal. The inter-phase short-circuit unit 40 is connected to 2-phase coils (coils Lu, Lv in fig. 1) of the 3-phase coils Lu, Lv, and Lw, and short-circuits respective coils of 3 groups (a group of coils Lu, Lv, a group of coils Lu, Lw, and a group of coils Lv, Lw) in which 2 coils of the 3-phase coils Lu, Lv, and Lw are different from each other in combination according to a short-circuit signal. The short-circuit signal output unit 50 is connected between the inter-phase short-circuit unit 40 and a 1-phase coil Lw, which is different from the 2-phase coils Lu, Lv, and Lw, of the 3-phase coils Lu, Lv, and Lw, and outputs a short-circuit signal to the inter-phase short-circuit unit 40 when a brake control signal is input thereto. The protection operation unit 60 stops short-circuiting between coils by the interphase short-circuiting unit 40 based on the state of the voltage of the 1-phase coil (coil Lw in fig. 1) among the 3-phase coils Lu, Lv, Lw.

As described above, the motor drive control device 1 according to embodiment 1 includes: a motor drive unit 10 that selectively energizes the 3-phase coils Lu, Lv, and Lw of the motor 3; a motor control unit 20 that switches the energization phases of the 3-phase coils Lu, Lv, and Lw energized by the motor drive unit 10 in a predetermined order by outputting a drive control signal to the motor drive unit 10; a brake control unit 30 that outputs a brake control signal; an interphase short-circuiting unit 40 connected to the 2-phase coils Lu, Lv of the 3-phase coils Lu, Lv, Lw, and short-circuiting respective inter-coils of 3 groups in which combinations of 2 coils of the 3-phase coils Lu, Lv, Lw are different from each other in accordance with a short-circuit signal; a short-circuit signal output unit 50 connected between the inter-phase short-circuit unit 40 and the 1-phase coil Lw of the 3-phase coils Lu, Lv, and Lw, and configured to output a short-circuit signal to the inter-phase short-circuit unit 40 when a brake control signal is input thereto; and a protection operation unit 60 configured to cancel the short circuit by the interphase short-circuit unit 40 based on the voltage state of the 1-phase coil Lw among the 3-phase coils Lu, Lv, and Lw. In the motor drive control method according to embodiment 1, the motor drive unit 10 selectively supplies power to the 3-phase coils Lu, Lv, and Lw of the motor 3, the motor control unit 20 outputs a drive control signal to the motor drive unit 10, thereby switching the supply phases of the 3-phase coils Lu, Lv, and Lw supplied with power from the motor drive unit 10 in a predetermined order, the brake control unit 30 outputs a brake control signal, the inter-phase short-circuiting unit 40 connected to the 2-phase coils Lu, Lv, and Lw of the 3-phase coils Lu, Lv, and Lw short-circuits the coils of 3 groups, in which combinations of 2 coils of the 3-phase coils Lu, Lv, and Lw are different from each other, in response to the short-circuit signal, and the short-circuit signal output unit 50 connected between the 1-phase coil Lw of the 3-phase coils Lu, Lv, and Lw and the inter-phase short-circuit unit 40 outputs a short-circuit signal to the inter-phase short-phase unit 40 when the brake control signal is input, the short circuit by the interphase short-circuit portion 40 is released by the protection operation portion 60 based on the state of the voltage of the 1-phase coil Lw among the 3-phase coils Lu, Lv, Lw.

Thus, the motor drive control device 1 does not need a floating circuit structure, and can brake the rotation of the motor with a simple structure. Further, the short-circuit signal output unit 50 of the motor drive control device 1 can output the short-circuit signal using the counter electromotive force generated by the 1-phase coil Lv, and therefore the motor drive control device 1 can realize a completely independent type power-supply-less brake.

Then, the motor drive control device 1 stops the short-circuit operation from a state in which the short-circuit operation between the coils of the motor 3 is performed, based on the state of the voltage of the 1-phase coil Lw among the 3-phase coils Lu, Lv, Lw. Thus, when the load of the motor 3 (for example, an external force for rotating the blades of the fan motor) is increased in a state where the motor drive control device 1 is not supplied with power, the load on the electronic components that perform the power-supply-free regenerative braking function can be reduced.

Hereinafter, the motor drive control device 1 according to embodiment 1 will be described in detail. The motor drive control device 1 is configured to drive the motor 3 by sine wave driving, for example. Further, the motor drive control device 1 brakes the rotation of the motor 3.

In embodiment 1, the motor 3 is, for example, a 3-phase brushless motor, and is, for example, a fan motor that rotates a fan or the like, not shown. The motor drive control device 1 causes the motor 3 to rotate by causing a sinusoidal drive current to flow to the coils Lu, Lv, and Lw of the armature of the motor 3. When it is determined that the rotation of the motor 3 is stopped or when the power supply from the power source 2 is cut off, the motor drive control device 1 brakes the rotation of the motor 3.

The motor drive unit 10 is an inverter circuit that outputs a drive signal to the motor 3 based on a drive control signal output from the motor control unit 20 and energizes the coils Lu, Lv, and Lw of the armature included in the motor 3. The motor drive unit 10 is configured such that, for example, a series circuit pair of 2 switching elements (a pair of switching elements Q1, Q2, a pair of switching elements Q3, Q4, and a pair of switching elements Q5, Q6) provided at both ends of the power supply 2 is arranged for each of the coils Lu, Lv, and Lw of the phases (U-phase, V-phase, and W-phase). In the present embodiment, the switching elements Q1 to Q6 are MOSFETs (Metal-Oxide-Semiconductor Field-effect transistors). In each of the 2 switching element pairs, a connection point between the switching elements is an output terminal, and terminals connected to the coils Lu, Lv, and Lw of the respective phases of the motor 3 are connected to the output terminals. Specifically, the connection point between switching elements Q1 and Q2 is an output terminal connected to the terminal of U-phase coil Lu. The connection point between switching elements Q3 and Q4 is an output terminal connected to a terminal of V-phase coil Lv. The connection point between switching elements Q5 and Q6 is an output terminal connected to the terminal of W-phase coil Lw.

The motor control unit 20 is constituted by, for example, a microcomputer, and controls each part of the motor drive control device 1. The motor control unit 20 includes a motor drive control unit 21 and a motor brake command unit 22.

The motor drive control unit 21 generates a drive control signal for driving the motor drive unit 10, and outputs the drive control signal to the motor drive unit 10. The generated drive control signals include, for example, Vuu, Vul, Vvu, Vvl, Vwu, and Vwl corresponding to the respective switching elements Q1 to Q6 of the motor drive unit 10. Specifically, the drive control signal Vuu is output to the switching element Q1, and the drive control signal Vul is output to the switching element Q2. Further, a drive control signal Vvu is output to the switching element Q3, and a drive control signal Vvl is output to the switching element Q4. Further, the drive control signal Vwu is output to the switching element Q5, and the drive control signal Vwl is output to the switching element Q6. By outputting these drive control signals, the switching elements Q1 to Q6 corresponding to the respective drive control signals are turned on and off, and drive signals are output to the motor 3 to supply electric power to the coils Lu, Lv, and Lw of the respective phases of the motor 3. When the rotation of the motor 3 is stopped, the switching elements Q1 to Q6 are all turned off. For example, when the motor brake command unit 22 outputs a brake command signal for braking the rotation of the motor 3, the motor drive control unit 21 turns off all of the switching elements Q1 to Q6.

The motor brake command unit 22 generates a brake command signal for braking the rotation of the motor 3 by the brake control unit 30, and outputs the brake command signal to the brake control unit 30. The motor brake command unit 22 generates a brake command signal as a Low signal when, for example, braking the rotation of the motor 3, and generates a non-brake command signal as a High signal when, for example, not braking the rotation of the motor 3. The generated brake command signal may be a High signal, and the non-brake command signal may be a Low signal.

The brake control unit 30 outputs a brake control signal to the short-circuit signal output unit 50. The brake control signal is a signal that is output when the inter-coil short circuit occurs in each of 3 groups in which 2 coils of the 3-phase coils Lu, Lv, and Lw are different from each other in combination, and is output to the short-circuit signal output unit 50 as described below, whereby the short-circuit signal is output from the short-circuit signal output unit 50 to the inter-phase short-circuit unit 40, and the inter-phase short-circuit unit 40 short-circuits the inter-coils of the 3 groups.

When the motor brake command unit 22 outputs a brake command signal for braking the rotation of the motor 3 or when the supply of electric power from the power supply 2 is cut off, the brake control unit 30 outputs a brake control signal.

For example, when the motor drive control unit 21 stops driving the motor 3, the motor brake command unit 22 outputs a brake command signal. Even if the motor drive control section 21 stops the drive of the motor 3, the motor 3 continues to rotate due to inertia. Therefore, the motor brake command unit 22 outputs a brake command signal to rapidly stop the rotation by inertia.

When the motor brake command unit 22 outputs a brake command signal, the brake control unit 30 detects a counter electromotive force generated by the rotation of the motor 3 due to inertia, and outputs a brake control signal using the detected counter electromotive force.

When the power supply from the power source 2 is cut off during the rotation driving of the motor 3, the motor driving unit 10 does not output a drive signal, but the motor 3 continues to rotate due to inertia. Therefore, in order to stop the rotation by inertia quickly, the brake control unit 30 detects the counter electromotive force and outputs a brake control signal using the detected counter electromotive force.

Alternatively, even when the motor 3 is rotated by an external force such as the fan is rotated by an external wind in a state where the rotation of the motor 3 is stopped and the power supply from the power source 2 is cut off, counter electromotive force is generated in the coils Lu, Lv, and Lw. In order to suppress rotation of the motor 3 due to an external force, the brake control unit 30 detects interruption of power supply and a counter electromotive force generated by the external force, and outputs a brake control signal using the detected counter electromotive force, thereby braking rotation of the motor 3.

The brake control unit 30 includes a power supply interruption detection circuit 41, a counter electromotive force detection circuit 42, a 1 st brake control circuit 43, and a 2 nd brake control circuit 44. As will be described in detail later, when the power supply interruption detection circuit 41 detects interruption of power supply during driving of the motor 3 by the motor drive unit 10, the brake control unit 30 outputs a brake control signal. When the power supply interruption detection circuit 41 detects interruption of the power supply and detects a counter electromotive force generated in the coil Lw (an example of the 1-phase coil) while the motor drive unit 10 stops driving the motor 3, the brake control unit 30 outputs a brake control signal.

The power supply interruption detection circuit 41 detects interruption of power supply from the power supply 2. The power supply interruption detection circuit 41 includes: a series circuit of resistive elements R1, R2 connected in parallel with the power source 2, and a resistive element R3 arranged between the series circuit and the 1 st brake control circuit 43. The power supply voltage of the power supply 2 is divided in accordance with the resistance values of the resistance elements R1 and R2. The power supply interruption detection circuit 41 outputs a power supply detection signal (High signal) corresponding to the divided voltage value to the 1 st brake control circuit 43. Further, since the power supply voltage value becomes zero when the power supply from the power supply 2 is cut off, the power supply cut-off detection circuit 41 outputs a cut-off detection signal (Low signal) indicating that the power supply is cut off.

The 1 st brake control circuit 43 switches between braking and non-braking of the motor 3 in accordance with the detection result of the interruption of the power supply from the power supply 2 by the power supply interruption detection circuit 41, or the braking command signal and the non-braking command signal output from the motor braking command unit 22.

The 1 st brake control circuit 43 has a switching element SW1, and 1 st and 2 nd diode elements D1 and D2. In the present embodiment, the switching element SW1 is a transistor, and the switching element SW1 has one end connected to the power supply 2 via the resistor element R5 and the other end connected to ground via the resistor element R6. One end of the switching element SW1 is connected to the 2 nd brake control circuit 44. The 1 st diode element D1 has an anode connected to the power supply cutoff detection circuit 41 and a cathode connected to the control terminal of the switching element SW 1. The 2 nd diode element D2 has an anode connected to the control terminal of the switching element SW1 and a cathode connected to the motor brake command unit 22.

For example, when the power supply 2 is not turned off and the power supply cut-off detection circuit 41 outputs a power supply detection signal (High signal), the 1 st diode element D1 is turned ON (ON). At this time, when the motor brake command unit 22 outputs a non-brake command signal (High signal) for not braking the rotation of the motor 3, the 2 nd diode element D2 is turned OFF (OFF), and therefore, the power detection signal is input to the control terminal of the switching element SW1 via the 1 st diode element D1, and the switching element SW1 is turned on.

On the other hand, when the power supply interruption detection circuit 41 outputs the power supply detection signal, if the motor brake command unit 22 outputs a brake command signal (Low signal) for braking the rotation of the motor 3, the 2 nd diode element D2 is turned on, and the power supply detection signal flows to the 2 nd diode element D2 side and is not input to the control terminal of the switching element SW 1. Accordingly, the switching element SW1 is turned off.

When the power shutoff detection circuit 41 outputs the shutoff detection signal (Low signal), no current flows to the 1 st diode element D1 regardless of the output of the motor brake command unit 22, and therefore no current is input to the control terminal of the switching element SW1, and the switching element SW1 is turned off.

In addition, as will be described in detail later, when the switching element SW1 of the 1 st brake control circuit 43 is turned off, the 2 nd brake control circuit 44 outputs a brake control signal in accordance with the detection result of the counter electromotive force detection circuit 42. On the other hand, when the switching element SW1 of the 1 st brake control circuit 43 is turned on, the 2 nd brake control circuit 44 does not output the brake control signal regardless of the detection result of the counter electromotive force detection circuit 42. The 1 st brake control circuit 43 controls the output of the 2 nd brake control circuit 44 by switching the switching element SW1 on/off, thereby switching the braking/non-braking of the motor 3.

The counter electromotive force detection circuit 42 detects the counter electromotive force generated in the coil Lw. The counter electromotive force detection circuit 42 has a resistance element R4 and a resistance element R7. When a back electromotive force is generated in the coil Lw, a voltage is applied to the control terminal of the switching element SW2 via the resistance element R7. These are operations for detecting the back electromotive force, and as a result, the switching element SW2 is turned on. A part of the current Iw flows to the resistor element R4 of the back electromotive force detection circuit 42, a voltage corresponding to the magnitude of the current flowing through the resistor element R4 and the resistance value of the resistor element R4 is generated at both ends of the resistor element R4, and a brake control signal is output from the brake control unit 30.

When the 1 st brake control circuit 43 switches from non-braking to braking of the motor 3, if a counter electromotive force is generated in the coil Lw, the 2 nd brake control circuit 44 outputs a brake control signal using the generated counter electromotive force. The 2 nd brake control circuit 44 has a switching element SW 2.

In the present embodiment, the switching element SW2 is a transistor and is provided between the counter electromotive force detection circuit 42 and the short-circuit signal output unit 50. The control terminal of the switching element SW2 is connected to the 1 st brake control circuit 43, and is connected to the coil Lw via the resistance element R7.

When the switching element SW1 of the 1 st brake control circuit 43 is turned off, that is, the power supply from the power source 2 is cut off, or the motor brake command unit 22 outputs a brake command signal, the counter electromotive force detection circuit 42 detects the counter electromotive force generated in the coil Lw. In this case, the current Iw flows to the switching element SW2, and the switching element SW2 is turned on. Thereby, the brake control signal is output from the 2 nd brake control circuit 44 to the short-circuit signal output unit 50.

On the other hand, when the switching element SW1 of the 1 st brake control circuit 43 is turned on, that is, electric power is supplied from the power supply 2 and the motor brake command unit 22 outputs the non-brake command signal, even if the counter electromotive force detection circuit 42 detects the counter electromotive force generated in the coil Lw, the current flowing through the coil Lw flows to the switching element SW1 of the 1 st brake control circuit 43 via the 2 nd brake control circuit 44. Therefore, the current Iw is not input to the control terminal of the switching element SW2, and the switching element SW2 is turned off. Therefore, the brake control signal is not output from the 2 nd brake control circuit 44 to the short-circuit signal output section 50.

Short-circuit signal output unit 50 is connected between coil Lw and inter-phase short-circuit unit 40. When the brake control signal is input from the 2 nd brake control circuit 44, the short-circuit signal output unit 50 outputs a short-circuit signal to the inter-phase short-circuit unit 40. The short-circuit signal output section 50 has a switching element SW 3. In the present embodiment, switching element SW3 is a thyristor, and has an anode connected to coil Lw, a cathode connected to inter-phase short circuit unit 40, and a gate connected to 2 nd brake control circuit 44.

The brake control signal output from the 2 nd brake control circuit 44 is input to the gate of the switching element SW 3. Thereby, switching element SW3 is turned on, and current Iw is output as a short-circuit signal to inter-phase short-circuit unit 40.

The interphase short-circuiting unit 40 is connected to the coils Lu, Lv, and short-circuits between coils (between the coils Lu, Lv, between the coils Lu, Lw, and between the coils Lv, Lw) of 3 groups in which 2 coils of the 3-phase coils Lu, Lv, and Lw are different from each other. Interphase short-circuiting portion 40 has 2 switching elements SW4, SW5 provided at both ends of coils Lu, Lv. In the present embodiment, the switching elements SW4 and SW5 are thyristors. The switching elements SW4 and SW5 have anodes connected to the coils Lv and Lu, respectively, and cathodes grounded to the ground. The gates of the switching elements SW4 and SW5 are connected to the short-circuit signal output unit 50 (specifically, the cathode of the switching element SW 3), and a short-circuit signal is input thereto. When the short-circuit signal is input, the switching elements SW4 and SW5 are turned on, and the coils Lu and Lv, the coils Lu and Lw, and the coils Lv and Lw are short-circuited.

For example, when a positive voltage is generated in the coil Lv and a negative voltage is generated in the coil Lw, the coil Lv and the coil Lw are short-circuited via the ground line via the switching element SW4 and the parasitic diode of the switching element Q6. Therefore, the current Iv flows through the coil Lv as a short-circuit current, and the current I6 flows through the coil Lw as a short-circuit current. When a positive voltage is generated in the coil Lv and a negative voltage is generated in the coil Lu, the coil Lv and Lu are short-circuited via the ground line by the parasitic diode of the switching element SW4 and the switching element Q2. Therefore, the current Iv flows through the coil Lv as a short-circuit current, and the current I2 flows through the coil Lu as a short-circuit current.

When a positive voltage is generated in the coil Lu and a negative voltage is generated in the coil Lw, the coil Lu and the coil Lw are short-circuited via the ground line by the parasitic diode of the switching element SW5 and the switching element Q6. Therefore, the current Iu flows as a short-circuit current through the coil Lu, and the current I6 flows as a short-circuit current through the coil Lw. When a positive voltage is generated in the coil Lu and a negative voltage is generated in the coil Lv, the coil Lu and the coil Lv are short-circuited via the ground line by the parasitic diode of the switching element SW5 and the switching element Q4. Therefore, the current Iu flows as a short-circuit current through the coil Lu, and the current I4 flows as a short-circuit current through the coil Lv.

In this way, inter-phase short-circuiting section 40 causes inter-coil short-circuiting of 3 groups each having a different combination of 2 coils among 3-phase coils Lu, Lv, and Lw. In addition, when the coils are short-circuited by the short-circuit signal output unit 50, the parasitic diodes of the switching elements Q2, Q4, and Q6 of the motor drive unit 10 are included in the regenerative path and operate as a part of the regenerative circuit. Therefore, the circuit for performing the self-standing type power-supply-less braking can be configured to be simple.

Further, by configuring interphase short-circuiting unit 40 with 2 thyristors, it is possible to simultaneously realize the function as a rectifier circuit and the function as a short-circuit, and it is possible to make interphase short-circuiting unit 40 a simple structure. Further, interphase short-circuiting portion 40 can be formed of a highly versatile member such as a thyristor as in the present embodiment.

When the brake control signal is output from the brake control unit 30, the protection operating unit 60 is in an operating state, and when the brake control signal is not output from the brake control unit 30, the protection operating unit 60 is in a non-operating state. This can avoid the situation where the protection operation unit 60 operates after the power supply to the motor 3 is stopped, and can avoid the influence on the brake control of the motor 3 when the power supply to the motor 3 is stopped.

When the voltage corresponding to the duration and magnitude of the back electromotive force generated in the coil Lw is equal to or greater than the threshold voltage Vth in a state where the brake control signal is output from the brake control unit 30, the protection operating unit 60 outputs a brake release command to the brake control unit 30, and stops the output of the brake control signal from the brake control unit 30. Accordingly, under the condition that the external force for rotating the motor 3 is applied for a long time, the load on the interphase short-circuit portion 40 and the parasitic diodes of the switching elements Q2, Q4, and Q6, which are responsible for the regenerative braking function without the power supply, can be reduced.

As shown in fig. 1, the protection operating unit 60 includes an activation time setting unit 61, a protection operation activating unit 62, and a brake release instructing unit 63. The start time setting unit 61 is connected to the 1-phase coil Lw of the 3-phase coils Lu, Lv, and Lw, and outputs a voltage corresponding to the duration of the counter electromotive force generated in the coil Lw and the counter electromotive force. When the voltage output from the activation time setting unit 61 is equal to or higher than a predetermined threshold voltage Vth1, the protection operation activation unit 62 outputs an activation signal for the protection operation (brake release) to the brake release instruction unit 63. When the activation signal is output from the protection operation activation unit 62, the brake release instruction unit 63 outputs a brake release signal for stopping the output of the brake control signal from the brake control unit 30 to the brake control unit 30. When the brake release signal is output from the protection operating unit 60, the brake control unit 30 stops the output of the brake control signal.

Fig. 2 is a block diagram showing an example of the circuit configuration of the motor drive control device according to embodiment 1, and shows configuration examples of the activation time setting unit 61, the protection operation activation unit 62, and the brake release command unit 63. As shown in fig. 2, the activation time setting unit 61 includes a diode element D3, a resistance element R8, and a capacitor C1. The diode element D3 has an anode connected to the coil Lw and a cathode connected to one end of the resistor element R8. The other end of the resistor R8 is connected to one end of the capacitor C1. The other end of the capacitor C1 is grounded to ground.

The back electromotive force generated in the coil Lw of the motor 3 is rectified by the diode element D3, and the rectified back electromotive force is output to a time constant circuit including the resistor element R8 and the capacitor C1. The voltage across the capacitor C1 rises based on a time constant determined by the resistor element R8 and the capacitor C1. Thus, the start time setting unit 61 can output a voltage corresponding to the duration and magnitude of the counter electromotive force generated in the coil Lw. Further, by adjusting the time constant determined by the resistance element R8 and the capacitor C1, the rate of increase of the voltage output from the activation time setting unit 61 can be adjusted. Hereinafter, the voltage output from the activation time setting unit 61 may be referred to as a smoothed voltage.

The protection operation activating unit 62 includes a resistor element R9, a switching element Q7, and a zener diode element D4. One end of the resistor R9 is connected to the output of the activation time setting unit 61, and the other end is connected to the control terminal of the switching element Q7. One end of the switching element Q7 is connected to the brake release command unit 63, and the other end is connected to the cathode of the zener diode element D4. The anode of the zener diode element D4 is grounded to the ground.

In the protection operation activating unit 62, when the smoothed voltage output from the activation time setting unit 61 is equal to or higher than the threshold voltage Vth1, the switching element Q7 is turned on, and an activation signal for the protection operation (brake release) is output from the switching element Q7 to the brake release instructing unit 63. Here, if the on voltage of the switching element Q7 is "V_BE", the Zener voltage of the Zener diode element D4 is set to" V_DZ", then Vth1 ═ V_BE+V_DZ。

The brake release command unit 63 includes a switching element Q8 and a diode element D5. The control terminal of the switching element Q8 is connected to the output of the protection operation activating unit 62. One end of the switching element Q8 is connected to the output of the activation time setting unit 61, and the other end is connected to the anode of the diode element D5. The cathode of the diode element D5 is connected to the control terminal of the switching element SW1 of the 1 st brake control circuit 43.

When the activation signal is output from the protection operation activation unit 62, the switching element Q8 is turned on in the brake release command unit 63. Thereby, a brake release command is output from the brake release command unit 63 to the control terminal of the switching element SW1 of the 1 st brake control circuit 43. In the 1 st brake control circuit 43, when a brake release command is input to the control terminal of the switching element SW1, the switching element SW1 is turned on. When the switching element SW1 of the 1 st brake control circuit 43 is turned on, the 2 nd brake control circuit 44 turns off the switching element SW 2. As a result, the 2 nd brake control circuit 44 stops the output of the brake control signal to the short-circuit signal output unit 50. That is, when the brake release signal is output from the protection operating unit 60, the brake control unit 30 stops the output of the brake control signal.

In this way, in a state where the brake control signal is output from the brake control unit 30, the protection operating unit 60 stops the output of the brake control signal from the brake control unit 30 at a timing (timing) corresponding to the duration and magnitude of the counter electromotive force generated in the coil Lw. Accordingly, for example, under the condition that an external force for rotating the motor 3 is applied for a long time, it is possible to avoid an excessive load amount generated by the regenerative braking in the interphase short-circuiting part 40 and the parasitic diodes of the switching elements Q2, Q4, and Q6.

The protection operating unit 60 is not limited to the configuration shown in fig. 2, and may be configured to output a brake release command at a timing corresponding to the duration and magnitude of the back electromotive force generated in the coil Lw. The protection operating unit 60 may output the brake release command at a timing corresponding to only the duration of the counter electromotive force generated in the coil Lw. For example, the following structure is also possible: a circuit for limiting the voltage is provided between the cathode of the diode element D3 and one end of the resistor element R8, and a brake release command is output at a timing corresponding to only the duration of the counter electromotive force.

As described above, the protection operation unit 60 operates when the brake control signal is output from the brake control unit 30. The protection operation unit 60 includes a switching element, not shown, between the coil Lw and the activation time setting unit 61. The control terminal of the switching element, not shown, is connected to the output of the brake control unit 30, and when a brake control signal is input, the coil Lw and the activation time setting unit 61 are connected. Thus, the protection operation unit 60 operates when the brake control signal is output from the brake control unit 30. The protection operating unit 60 may be in an operating state when the brake control signal is output from the brake control unit 30, and the configuration for switching between the operating state and the non-operating state of the protection operating unit 60 is not limited to the above example. For example, the following structure is also possible: a switching element for short-circuiting both ends of the capacitor C1 is provided, and the switching element is turned off when a brake control signal is output from the brake control unit 30.

Next, an operation mode of the braking operation of the motor drive control device 1 will be described with reference to fig. 1 to 3. Fig. 3 is a diagram illustrating an operation mode of the motor drive control device 1 according to embodiment 1. As described above, the motor drive control device 1 brakes the rotation of the motor 3 when the power supply from the power source 2 is cut off or when the motor brake command unit 22 outputs a brake command signal. The operation of the motor drive control device 1 for braking is divided into 3 operation modes a to C as shown in fig. 3.

First, when the motor control unit 20 rotates without braking the motor 3 (operation mode a), as shown in fig. 3, electric power from the power supply 2 is supplied to the motor drive control device 1, and a non-braking command signal (High signal) is output from the motor braking command unit 22. In this case, the 1 st diode element D1 of the 1 st brake control circuit 43 is turned on, the 2 nd diode element D2 is turned off, and the switching element SW1 is turned on. Accordingly, even if a back electromotive force is generated in the motor 3, the switching elements SW2 and SW3 are both turned off, and neither the brake control signal nor the short-circuit signal is output, so that the braking operation (no braking) of the motor drive control device 1 is not performed.

For example, the motor control unit 20 determines that the rotation of the motor 3 is stopped, the motor drive control unit 21 stops the driving of the motor 3, and the motor brake command unit 22 brakes the motor 3 (operation mode B). In this case, the motor drive control device 1 is supplied with electric power from the power supply 2, and a brake command signal (Low signal) is output from the motor brake command unit 22. In this case, the 1 st diode element D1 and the 2 nd diode element D2 are both turned on, and the switching element SW1 is turned off. At this time, when a counter electromotive force is generated in the motor 3, the switching element SW2 is turned on, a brake control signal is generated using the counter electromotive force generated in the motor 3, and the switching element SW3 is turned on by the brake control signal to generate a short-circuit signal. Thereby, switching elements SW4 and SW5 of interphase short-circuiting portion 40 are turned on, and the rotation of motor 3 is braked (braked).

In this way, when the motor control unit 20 stops the rotational driving of the motor 3, the motor drive control device 1 can brake the rotation of the motor 3 using the counter electromotive force generated in the motor 3 by inertia.

When the power supply from the power source 2 to the motor drive control device 1 is cut off and no power is supplied (operation mode C), both the 1 st diode element D1 and the 2 nd diode element D2 are turned off, and the switching element SW1 is turned off. At this time, when a counter electromotive force is generated in the motor 3, the switching element SW2 is turned on, a brake control signal is generated using the counter electromotive force generated in the motor 3, and the switching element SW3 is turned on by the brake control signal to generate a short-circuit signal. Thereby, switching elements SW4 and SW5 of interphase short-circuiting portion 40 are turned on, and the rotation of motor 3 is braked (braked).

In the operation mode C, when the power supply from the power supply 2 is cut off, the motor drive control device 1 brakes the rotation of the motor 3, regardless of whether the motor 3 is being driven to rotate by the motor control unit 20 or stopped to rotate. That is, when the power supply from the power supply 2 is cut off regardless of whether the signal output from the motor brake command unit 22 is the non-brake command signal or the brake command signal before the power supply is cut off, the motor drive control device 1 brakes the rotation of the motor 3.

Therefore, for example, when the rotation of the motor 3 is stopped and the power supply is cut off, the rotation of the motor 3 by the external force can be braked. Thus, for example, the motor 3 is a fan motor, and measures against the generation of forced rotation by outside wind when installed in the user system can be realized.

In this way, the motor drive control device 1 can brake the rotation of the motor 3 when the power supply from the power source 2 is cut off, and can stop the rotation of the motor 3 more quickly. Further, since the motor drive control device 1 brakes the rotation using the counter electromotive force generated in the motor 3, even when the power supply from the power supply 2 is cut off, it is not necessary to provide a battery independent of the power supply 2, and a completely self-contained, power-supply-less braking operation can be performed. Further, since the motor drive control device 1 detects the interruption of the power supply and outputs the brake command signal, it is not necessary to separately provide an external device that detects the interruption of the power supply and outputs the brake command signal, and the self-standing brake system can be realized by the motor drive control device 1.

After the motor drive control device 1 starts braking the rotation of the motor 3, the motor drive control device stops braking the rotation of the motor 3 at a timing corresponding to the duration and magnitude of the counter electromotive force generated in the coil Lw, and performs a protective operation. This can avoid the external force for rotating the motor 3 being continuously applied for a long time, and avoid an excessive load being generated in the inter-phase short circuit portion 40 and the parasitic diodes of the switching elements Q2, Q4, and Q6 due to regenerative braking.

The protection operation start time of the protection operation unit 60 is set so that the protection operation by the motor drive control device 1 is not started until the braking operation by the operation pattern B is completed. The protection operation start time is a time after the brake control signal is generated until the protection operation of the protection operation unit 60 is started, and can be appropriately set by adjusting a time constant of a time constant circuit provided in the activation time setting unit 61, for example. Accordingly, the braking operation in the operation pattern B is not stopped by the protection operation of the protection operation unit 60, and therefore the braking operation in the operation pattern B can be appropriately performed.

Next, the operation sequence of the protection operation unit 60 of the motor drive control device 1 will be described with reference to fig. 4. Fig. 4 is a flowchart illustrating an example of the operation procedure of the protection operation unit 60 of the motor drive control device 1. Fig. 4 illustrates an operation of the motor drive control device 1 in a case where an external force is applied to the motor 3 and the motor 3 rotates in a state where power is not supplied to the motor 3.

As shown in fig. 4, when an external force acts on the motor 3 in a state where power is not supplied to the motor 3 and the motor 3 rotates, a counter electromotive force (counter electromotive force) is generated in the coil Lw of the motor 3 (step S101). When a back electromotive force is generated in the coil Lw, the start-up time setting unit 61 of the protection operation unit 60 rectifies the back electromotive force generated in the coil Lw (step S102), and smoothes the rectified back electromotive force (step S103).

When the back electromotive force continues to be generated in the coil Lw, the smoothed voltage output from the start time setting unit 61 rises (step S104). The protection operation activating unit 62 detects whether or not the smoothed voltage output from the activation time setting unit 61 is equal to or higher than the threshold voltage Vth1 (step S105). When the smoothed voltage is not equal to or higher than the threshold voltage Vth1 (no in step S105), the protection operation activation unit 62 continues the detection in step S105.

On the other hand, when the smoothed voltage output from the activation time setting unit 61 is equal to or higher than the threshold voltage Vth1 (yes in step S105), the switching element Q7 of the protection operation activating unit 62 is turned on, and an activation signal for the protection operation (brake release) is output from the protection operation activating unit 62 (step S106). When the activation signal is output from the protection operation activation unit 62, the switching element Q8 of the brake release instruction unit 63 is turned on (step S107), and the switching element SW1 of the 1 st brake control circuit 43 is turned on (step S108). Thereby, the output of the brake control signal from the brake control unit 30 is stopped, and the release of the braking operation by the short circuit of the inter-phase short circuit unit 40 is stopped (step S109).

Next, a specific example of the effect of the protective operation by the motor drive control device 1 will be described with reference to fig. 5. Fig. 5 is a diagram for explaining an example of the effect of the protective operation by the motor drive control device 1, and shows an example of a case where external wind is forcibly blown to the fan attached to the motor 3 to forcibly rotate the motor 3 during the motor drive stop. In fig. 5, the brake function release indicates a state in which the brake operation of the motor drive control device 1 is not enabled (for example, a state in which the brake control signal is not output), and the brake function remains a state in which the brake operation of the motor drive control device 1 is enabled (for example, a state in which the brake control signal can be output).

As shown in FIG. 5The rotation speed when the brake function is released becomes larger in proportion to the volume of the outside air. On the other hand, the rotation speed at the time of releasing the braking function was set at a forced air volume of 5[ m ]³/min]The motor drive control device 1 is started to perform a braking operation until the forced air flow rate reaches 15 m³/min]The braking operation of the motor drive control device 1 is maintained until the vicinity. By this braking operation, the short-circuit current flows through the switching elements SW4 and SW5, and therefore the temperatures of the switching elements SW4 and SW5 rise.

If the forced air volume is 15 m³/min]As described above, the motor drive control device 1 starts the protection operation and stops the braking operation of the motor drive control device 1. Therefore, the short-circuit current does not flow through the switching elements SW4 and SW5, and the temperatures of the switching elements SW4 and SW5 decrease. In this way, when the load on the motor 3 increases in a state where no electric power is supplied to the motor 3, the load on the electronic components that perform the power-supply-less regenerative braking function can be reduced.

In fig. 5, the forced air volume and the forced rotation speed at which the protection operation is started are examples, and are not limited to the examples shown in fig. 5. The timing of starting the protection operation also varies depending on the rotation speed of the motor 3, the number of windings, the shape of the impeller, and the like.

In embodiment 1, since the back electromotive energy generated in the coil Lw is used as a power source for the braking function and the protection operation, a separate power source such as a battery is not required, and a completely self-contained power-free operation can be realized. In particular, the braking function and the protection function suppress the generation of forced rotation by external wind when the motor 3 is installed as a fan motor in a consumer system, for example, and stop the braking operation when a load on an electronic component that bears the power-supply-less regenerative braking function is large. This reduces the load on the electronic component that performs the power-supply-less regenerative braking function.

In addition, in embodiment 1, it is not necessary to use a mechanical relay or a mechanical switch in order to realize the above-described braking function, and the reliability of the motor drive control device 1 can be improved and the product life can be made longer.

In fig. 1 and 2, 2 switching elements SW4 and SW5 of interphase short-circuiting unit 40 are thyristors, but the present invention is not limited thereto. For example, the interphase short-circuiting portion 40 may be implemented by one triac. Fig. 6 is a diagram showing a modification of interphase short-circuiting portion 40 in such a case. As shown in fig. 6, a triac is disposed between the coils Lu and Lv, and a short-circuit signal is input from the short-circuit signal output unit 50 to the gate of the triac. In this case, the interphase short-circuiting section 40 does not need to be grounded to the ground, and parasitic diodes of the switching elements Q2, Q4, and Q6 of the motor driving section 10 do not need to be used in the regenerative path. In fig. 6, components that are not necessary for the description of the components of the motor drive control device 1 are not shown.

Further, the interphase short-circuiting section 40 may be implemented by 3 switching elements SW4, SW5, SW 7. In this case, as shown in fig. 7, switching element SW7 connected to coil Lw is added in addition to the configuration of interphase short-circuiting portion 40 shown in fig. 1. The switching element SW7 is a thyristor, and a short-circuit signal is input from the short-circuit signal output unit 50 to the gate of the switching element SW 7. Further, the current Iw1 is used for detection of the back electromotive force and output of the brake control signal and output of the short-circuit signal, and the short-circuit current Iw2 is a current flowing through the switching element SW7 when a positive back electromotive force is generated in the coil Lw.

Therefore, in the interphase short-circuiting portion 40 shown in fig. 7, even when the coil Lw is a positive voltage and either of the coils Lu and Lv is a negative voltage, the coil Lu and Lw or the coil Lv and Lw is short-circuited. Thus, the following configuration may be adopted: the inter-phase short-circuit unit 40 is connected to the 3-phase coils Lu, Lv, and Lw, and short-circuits the inter-coils of 3 groups, each having a different combination of 2 coils in the 3-phase coils Lu, Lv, and Lw, in accordance with the short-circuit signal. In this case, the protection operation unit 60 is connected to any 1-phase coil among the 3-phase coils Lu, Lv, and Lw.

In addition, although interphase short-circuiting portion 40 shown in fig. 6 has a configuration including one triac, a configuration in which 3 triac elements are provided may be employed. In this case, in the interphase short-circuiting portion 40, in addition to between the coils Lu and Lv, triac elements are disposed between the coils Lu and Lw and between the coils Lv and Lw, respectively. Then, a short-circuit signal is input from the short-circuit signal output unit 50 to the gates of the 3 triac elements. This can short-circuit the coils Lu and Lw and the coils Lv and Lw, in addition to the coils Lu and Lv. In this case, similarly to the configuration shown in fig. 7, the protection operating unit 60 is connected to any 1-phase coil among the 3-phase coils Lu, Lv, and Lw.

(embodiment 2)

The motor drive control device of embodiment 2 differs from the motor drive control device 1 of embodiment 1 in the following respects: when the magnitude of the counter electromotive force generated in the 1-phase coil among the 3-phase coils is equal to or greater than a predetermined value, the braking operation of the motor is not stopped, and the braking force of the motor is suppressed. Hereinafter, the same reference numerals are given to the components having the same functions as those of embodiment 1, and the description thereof will be omitted, and the differences from the motor drive control device 1 of embodiment 1 will be mainly described.

Fig. 8 is a block diagram showing an example of the circuit configuration of the motor drive control device 1A according to embodiment 2. As shown in fig. 8, the motor drive control device 1A according to embodiment 2 includes a motor drive unit 10, a motor control unit 20, a brake control unit 30, an inter-phase short-circuit unit 40, a short-circuit signal output unit 50, and a protection operation unit 70.

The protection operation unit 70 suppresses the short-circuit current by the interphase short-circuit unit 40 based on the state of the voltage of the 1-phase coil Lw among the 3-phase coils Lu, Lv, and Lw. The suppression of the short-circuit current means to reduce the amount of current flowing due to the short-circuit of the short-circuit signal output section 50.

The protection operation unit 70 includes a back electromotive force level monitoring unit 71, a protection operation starting unit 72, a braking force change command unit 73, and a braking force switching unit 74. The counter electromotive force level monitoring unit 71 is connected to the 1-phase coil Lw among the 3-phase coils Lu, Lv, and Lw, and outputs a voltage corresponding to the magnitude of the counter electromotive force generated in the coil Lw. The protection operation starting unit 72 detects whether or not the magnitude of the back electromotive force generated in the coil Lw is equal to or greater than a predetermined value. For example, when the voltage output from the counter electromotive force level monitoring unit 71 is a preset threshold voltage Vth2, the protection operation starting unit 72 outputs a starting signal of the protection operation (braking force change) to the braking force change command unit 73. When the activation signal is output from the protection operation activation unit 72, the braking force change command unit 73 outputs a braking force change signal to the brake control unit 30, which causes the braking force switching unit 74 to suppress the short-circuit current. When the braking force change signal is output from the braking force change command unit 73, the braking force switching unit 74 suppresses the short-circuit current generated by the short-circuit of the short-circuit signal output unit 50, thereby suppressing the braking force of the interphase short-circuit unit 40 on the motor 3.

Fig. 9 is a block diagram showing an example of a circuit configuration of the motor drive control device 1A according to embodiment 2, and shows configuration examples of the back electromotive force level monitoring unit 71, the protection operation starting unit 72, the braking force change command unit 73, and the braking force switching unit 74, respectively. As shown in fig. 9, the back electromotive force level monitoring unit 71 includes a diode element D6 and a capacitor C2. The diode element D6 has an anode connected to the coil Lw and a cathode connected to one end of the capacitor C2. The other end of the capacitor C2 is grounded to ground. The counter electromotive force (counter electromotive force) generated in the coil Lw of the motor 3 is rectified by the diode element D6 and smoothed by the capacitor C2. The larger the counter electromotive force (counter electromotive force), the larger the smoothing voltage which is the voltage across both ends of the capacitor C2.

The protection operation starting unit 72 has a series circuit of resistance elements R11 and R12 connected in parallel to the capacitor C2 of the back electromotive force level monitoring unit 71. The smoothed voltage output from the counter electromotive force level monitoring unit 71 is divided in accordance with the resistance values of the resistance elements R11 and R12. When the smoothed voltage is equal to or higher than the threshold voltage Vth2, the protection operation activation unit 72 outputs an activation signal for the protection operation (braking force change).

The braking force change command unit 73 includes resistance elements R13 and R14, and switching elements Q9 and Q10. One end of the resistor element R13 and one end of the resistor element R14 are connected to the coil Lw, respectively. The other end of the resistor R13 is connected to one end of the switching element Q9, and the other end of the resistor R14 is connected to one end of the switching element Q10. The other end of the switching element Q9 is grounded to the ground line, and the control terminal and the protection operation are startedThe portions 72 are connected. When the protection operation starting unit 72 outputs a start signal to the control terminal of the switching element Q9, the switching element Q9 is turned on. The start signal is a voltage signal equal to or higher than the on voltage of the switching element Q9, and the on voltage of the switching element Q9 is set to V_BEThe threshold voltage Vth2 is changed from Vth2 to V_BE× (R11+ R12)/R12, when the motor driving unit 10 outputs the maximum rated voltage, the switching element Q9 can be turned off when the motor 3 is driven by the motor driving unit 10 by increasing the threshold voltage Vth2 to be higher than the smoothed voltage output from the counter electromotive force level monitoring unit 71.

When the switching element Q9 is turned off in a state where a back electromotive force is generated in the coil Lw, the switching element Q10 is turned on, and a non-braking force change signal is output from the switching element Q10. The non-braking force change signal is a signal for applying a voltage to the braking force switching unit 74. On the other hand, when the switching element Q9 is turned on, the switching element Q10 is turned off. Therefore, the switching element Q10 outputs a braking force change signal. The braking force change signal is a signal for stopping the application of voltage to the braking force switching unit 74.

The braking force switching unit 74 includes: a parallel circuit of the switching element SW8 and the resistance element R20, and a parallel circuit of the switching element SW9 and the resistance element R21. A parallel circuit of the switching element SW8 and the resistance element R20 is connected between the coil Lv and the anode of the switching element SW 4. A parallel circuit of the switching element SW9 and the resistance element R21 is connected between the coil Lu and the anode of the switching element SW 5.

Until the braking force change signal is output from the switching element Q10 of the braking force change command unit 73, the non-braking force change signal is output from the switching element Q10, and the switching elements SW8 and SW9 are turned on. Therefore, short-circuit currents Iv and Iu flow to inter-phase short-circuit unit 40 via switching elements SW8 and SW 9. On the other hand, when the braking force change signal is output from the switching element Q10, the switching elements SW8 and SW9 are turned off, and the short-circuit currents Iv and Iu flow to the inter-phase short-circuit portion 40 via the resistance elements R20 and R21. Therefore, when the braking force change signal is output from the switching element Q10, the short-circuit currents Iv and Iu and the short-circuit currents I2, I4, and I6 are suppressed as compared with the case where the braking force change signal is not output from the switching element Q10. Therefore, the braking force of the interphase short-circuiting portion 40 on the motor 3 is suppressed.

In this way, when the counter electromotive force generated in the coil Lw is equal to or greater than a predetermined value, the protection operation unit 70 suppresses the braking force of the inter-phase short circuit unit 40 on the motor 3. Accordingly, for example, under the condition that the external force for rotating the motor 3 is large, it is possible to avoid an excessive load amount generated in the inter-phase short circuit portion 40 and the parasitic diodes of the switching elements Q2, Q4, and Q6 due to regenerative braking.

The protection operating unit 70 is not limited to the configuration shown in fig. 9, and may be configured to output a braking force change command when the counter electromotive force generated in the coil Lw is equal to or higher than a set voltage.

Next, the operation sequence of the protection operation unit 70 of the motor drive control device 1A will be described with reference to fig. 10. Fig. 10 is a flowchart illustrating an example of the operation procedure of the protection operation unit 70 of the motor drive control device 1A according to embodiment 2. In fig. 10, the operation of the motor drive control device 1A in the case where an external force is applied to the motor 3 to rotate the motor 3 in a state where power is not supplied to the motor 3 will be described.

As shown in fig. 10, when an external force acts on the motor 3 to rotate the motor 3 in a state where power is not supplied to the motor 3, a counter electromotive force (counter electromotive force) is generated in the coil Lw of the motor 3 (step S201). When a counter electromotive force is generated in the coil Lw, the switching element Q10 of the braking force change command unit 73 is turned on (step S202). When the switching element Q10 is turned on, the switching elements SW8 and SW9 of the braking force switching unit 74 are turned on (step S203).

The back electromotive force generated in the coil Lw of the motor 3 is rectified and smoothed by the back electromotive force level monitoring unit 71 (step S204). The protection operation starting unit 72 detects whether or not the smoothed voltage output from the counter electromotive force level monitoring unit 71 is equal to or higher than the threshold voltage Vth2 (step S205). When the smoothed voltage does not rise to the threshold voltage Vth2 (no in step S205), the protection operation activation unit 72 does not output an activation signal for the protection operation (braking force change). On the other hand, when the smoothed voltage rises to the threshold voltage Vth2 (yes in step S205), the protection operation activating unit 72 outputs an activation signal to turn off the switching element Q9 (step S206).

When the switching element Q9 is turned off, the switching element Q10 is turned off (step S207). Accordingly, the switching elements SW8, SW9 of the braking force switching unit 74 are turned off (step S208). Therefore, the resistive elements R20 and R21 are connected to the short-circuit paths of the coils Lv and Lu (step S209), and the short-circuit currents Iv and Iu flow to the interphase short-circuit portion 40 via the resistive elements R20 and R21. This suppresses the braking force of inter-phase short circuit unit 40 on motor 3 (step S210).

In embodiment 2, since the back electromotive energy generated in the coil Lw is used as a power source for the braking function and the protection operation, a separate power source such as a battery is not required, and a completely independent type power-free operation can be realized. In particular, the braking function and the protection function suppress, for example, generation of forced rotation by external wind when the motor 3 is installed as a fan motor in a consumer system, and suppress braking force when a load on an electronic component that bears the power-supply-less regenerative braking function is large. This reduces the load on the electronic component that performs the power-supply-less regenerative braking function.

In addition, in the present embodiment, it is not necessary to use a mechanical relay or a mechanical switch in order to realize the above-described braking function, and the reliability of the motor drive control device 1A can be improved and the product life can be made longer.

In fig. 8 and 9, 2 switching elements SW4 and SW5 of interphase short-circuiting unit 40 are thyristors, but the present invention is not limited thereto. For example, as shown in fig. 11, the interphase short-circuiting portion 40 may be implemented by one triac. In the example shown in fig. 11, a triac is disposed between the coils Lu and Lv, and a short-circuit signal is input from the short-circuit signal output unit 50 to the gate of the triac. The braking force switching unit 74 of the protection operating unit 70 is formed of a parallel circuit of the switching element SW11 and the resistance element R20. A parallel circuit of switching element SW11 and resistance element R20 is arranged between coil Lv and interphase short-circuiting portion 40, and switching element SW11 is a triac. The braking force switching unit 74 may be disposed between the coil Lu and the inter-phase short circuit unit 40. The switching element SW11 may not be a triac.

Further, interphase short-circuiting portion 40 may be implemented by 3 switching elements SW4, SW5, SW 7. In this case, as shown in fig. 12, in addition to the structure of interphase short-circuiting portion 40 shown in fig. 8, switching element SW7 connected to coil Lw is added. The switching element SW7 is a thyristor, and a short-circuit signal is input from the short-circuit signal output unit 50 to the gate of the switching element SW 7. In this case, the braking force switching unit 74 has a parallel circuit of the switching element SW10 and the resistance element R22 arranged between the coil Lw and the switching element SW7, in addition to the configuration shown in fig. 8. In the case of the configuration shown in fig. 12, the protection operating unit 70 is connected to any 1-phase coil among the 3-phase coils Lu, Lv, and Lw.

In addition, although interphase short-circuiting portion 40 shown in fig. 11 has a configuration including one triac, it may be configured to provide 3 triac elements, as in embodiment 1. In this case, in interphase short-circuiting portion 40, a parallel circuit of a switching element and a resistor, which is a triac, is connected in series with each triac. In this case, similarly to the configuration shown in fig. 12, the protection operating unit 70 is connected to any 1-phase coil among the 3-phase coils Lu, Lv, and Lw.

In addition, in the present embodiment, it is not necessary to use a mechanical relay or a mechanical switch in order to realize the above-described braking function, and the reliability of the motor drive control device 1A can be improved and the product life can be made longer.

In the configuration of each part of the motor drive control devices 1 and 1A and the configuration of the motor 3 in the above embodiments, the coils Lu, Lv, and Lw are star-shaped connection lines, but connection lines of the coils Lu, Lv, and Lw of the motor 3 may be triangular connection lines. The triac may be replaced with a bidirectional switch such as a Metal-Oxide-Semiconductor (MOS) relay or a mechanical relay.

In addition, the example in which the protection operation unit 60 of the motor drive control device 1 of the above embodiment operates in a state in which the brake control signal is output from the brake control unit 30 has been described, but the present invention is not limited thereto. For example, the protection operating unit 60 may be set to the operating state when a certain period of time has elapsed after the state of the operation mode a or the operation mode B has shifted to the state of the operation mode C.

The protection operation unit 70 of the motor drive control device 1A of the above embodiment sets the threshold voltage Vth2 so that the protection operation is not performed at the voltage output from the motor drive unit 10, but the present invention is not limited to this. For example, the protection operating unit 70 may be configured to operate in a state where the brake control signal is output from the brake control unit 30, or may be configured to operate in a state where a certain period of time has elapsed after the state of the operation mode C is shifted, and the threshold voltage Vth2 may be made smaller than in the case of the above example, as in the protection operating unit 60.

Further, although the protection operating unit 60 of the motor drive control device 1 of the above embodiment stops the braking operation of the inter-phase short circuit unit 40, the braking operation of the inter-phase short circuit unit 40 may be suppressed similarly to the protection operating unit 70. In this case, the protection operation unit 60 has a circuit similar to that of the braking force switching unit 74, and controls the braking force switching unit 74 to suppress the amount of short-circuit current flowing between the motor 3 and the interphase short-circuit unit 40 when the duration of the counter electromotive force generated in the 1-phase coil and the voltage corresponding to the counter electromotive force are equal to or greater than the threshold voltage Vth 1.

Further, although the protection operating unit 70 of the motor drive control device 1A of the above embodiment suppresses the braking force of the inter-phase short circuit unit 40, the braking operation of the inter-phase short circuit unit 40 may be stopped similarly to the protection operating unit 60. In this case, the protection operating unit 70 may stop the output of the brake control signal from the brake control unit 30 when the back electromotive force generated in the 1-phase coil is equal to or greater than a predetermined value without providing the braking force switching unit 74.

The motor drive control device 1A according to the above embodiment may have the protection operating unit 60 according to embodiment 1 in addition to the protection operating unit 70. Thus, the motor drive control device 1A can reduce the load on the electronic components that perform the power-supply-less regenerative braking function even when the external force for rotating the motor 3 is large, in addition to the condition that the external force for rotating the motor 3 is applied for a long time.

The configurations of the respective portions of the motor drive control devices 1 and 1A according to the above embodiments are not limited to the configurations shown in fig. 1, 9, and 10. For example, a part or all of the configuration of the brake control unit 30 may be realized by either hardware or software.

The inter-phase short-circuit unit 40 of the motor drive control devices 1 and 1A is connected to the coils Lu and Lv, but is not limited to this, and the inter-phase short-circuit unit 40 may be connected to the coils Lv and Lw or the coils Lu and Lw. When the inter-phase short-circuit unit 40 is connected to the coils Lv and Lw, the protection operating units 60 and 70 may be connected to the coil Lu, and when the inter-phase short-circuit unit 40 is connected to the coils Lu and Lw, the protection operating units 60 and 70 may be connected to the coil Lv.

The motor control unit 20 of the motor drive control devices 1 and 1A may be driven by a power source other than the power source 2. In this case, for example, the motor control unit 20 may be mounted as an IC different from the IC on which the motor drive control device 1 or 1A is mounted. In this way, by driving the motor control unit 20 by a power source other than the power source 2, the motor control unit 20 can output the brake command signal even if the power supply from the power source 2 is cut off.

In the above-described embodiment, the motor control unit 20 of the motor drive control device 1 or 1A determines whether or not to brake the motor 3, but is not limited thereto. For example, the motor drive control devices 1 and 1A may be controlled so that the motor 3 is braked by an external device other than the motor control unit 20, such as braking the motor 3 when the user presses an emergency stop button. In this case, a terminal for inputting a braking command from an external device is added to the 1 st braking control circuit 43. This makes it possible to forcibly stop the motor 3 quickly, for example, when the motor 3 needs to be stopped in an emergency.

The short-circuit signal output unit 50 of the motor drive control devices 1 and 1A is not limited to the configuration of the present embodiment. The components may include components other than thyristors. For example, the short-circuit signal output unit 50 may be implemented by using a mechanical switch (mechanical contact relay or the like). In this case, a design considering long-term reliability such as a countermeasure against a contact failure is desired.

The present invention is not limited to the above embodiments. The present invention includes a structure in which the above-described constituent elements are appropriately combined. Further, those skilled in the art can easily derive further effects and modifications. Thus, the broader aspects of the present invention are not limited to the above-described embodiments, and various modifications are possible.

Description of reference numerals

1. 1a … motor drive control device; 2 … power supply; 3 … electric motor; 10 … motor drive part; 20 … motor control part; 21 … motor drive control part; 22 … motor braking command part; 30 … brake control unit; 40 … interphase short-circuiting portion; 41 … power cut detection circuit; 42 … back emf detection circuit; 43 … braking control circuit 1; 44 …, 2 nd brake control circuit; 50 … short circuit signal output part; 60. 70 … protection operation part; 61 … start time setting unit; 62. 72 … protection action starting part; 63 … a brake release command unit; 71 … back electromotive force level monitoring section; 73 … braking force change command unit; 74 … braking force switching part; c1, C2 … capacitors; lu, Lv, Lw … coils; Q1-Q10 … switching elements; vuu, Vul, Vvu, Vvl, Vwu, Vwl … drive control signals; R1-R9, R11-R14, R20-R22 … resistance elements; SW1, SW2, SW6 … switching elements (transistors); SW3, SW4, SW5, SW7 to SW10 … switching elements (thyristors); an SW11 … switching element (triac); d1 … 1 st diode element; d2 …, 2 nd diode element; d3, D5, D6 … diode elements; a D4 … zener diode element; iw, Iw1 … current; iu, Iv, Iw2, I2, I4, I6 … short circuit current.