阅读说明：本技术 电力转换装置、驱动装置以及助力转向装置 (Power conversion device, drive device, and power steering device ) 是由 锅师香织 于 2019-02-08 设计创作，主要内容包括：电力转换装置具有：第1逆变器,其具有上臂元件和下臂元件,并与马达的各相绕组的一端连接；第2逆变器,其具有上臂元件和下臂元件,并与和所述一端相对的另一端连接；第1电源,其向所述第1逆变器的所述上臂元件和所述第2逆变器的所述下臂元件提供电力；以及第2电源,其向所述第2逆变器的所述上臂元件和所述第1逆变器的所述下臂元件提供电力。(The power conversion device includes: a 1 st inverter having an upper arm element and a lower arm element and connected to one end of each phase winding of the motor; a 2 nd inverter having an upper arm element and a lower arm element and connected to the other end opposite to the one end; a 1 st power supply that supplies power to the upper arm element of the 1 st inverter and the lower arm element of the 2 nd inverter; and a 2 nd power supply that supplies power to the upper arm element of the 2 nd inverter and the lower arm element of the 1 st inverter.)

1. A power conversion device has:

a 1 st inverter having an upper arm element and a lower arm element and connected to one end of each phase winding of the motor;

a 2 nd inverter having an upper arm element and a lower arm element and connected to the other end opposite to the one end;

a 1 st power supply that supplies power to the upper arm element of the 1 st inverter and the lower arm element of the 2 nd inverter; and

a 2 nd power supply that supplies power to the upper arm element of the 2 nd inverter and the lower arm element of the 1 st inverter.

2. The power conversion apparatus according to claim 1,

the power conversion device includes a control unit that drives the 1 st inverter and the 2 nd inverter using the other power source when one of the 1 st power source and the 2 nd power source malfunctions.

3. The power conversion apparatus according to claim 2,

the control unit includes:

a 1 st control unit that controls the upper arm element of the 1 st inverter and the lower arm element of the 2 nd inverter; and

a 2 nd control unit that controls the upper arm element of the 2 nd inverter and the lower arm element of the 1 st inverter,

the 1 st control unit performs control according to whether or not the 2 nd side drive system including the 2 nd power supply and the 2 nd control unit operates normally,

the 2 nd control unit performs control according to whether or not the 1 st side drive system including the 1 st power supply and the 1 st control unit operates normally.

4. The power conversion apparatus according to any one of claims 1 to 3,

the power conversion device includes:

a 1 st mounting substrate on which the upper arm element of the 1 st inverter and the lower arm element of the 2 nd inverter are mounted; and

a 2 nd mounting substrate on which the upper arm element of the 2 nd inverter and the lower arm element of the 1 st inverter are mounted.

5. The power conversion apparatus according to any one of claims 1 to 3,

the power conversion device has a double-sided mounting board on which the upper arm element of the 1 st inverter and the lower arm element of the 2 nd inverter are mounted on one of front and back surfaces, and the upper arm element of the 2 nd inverter and the lower arm element of the 1 st inverter are mounted on the other surface opposite to the one surface.

6. A drive device, comprising:

the power conversion device according to any one of claims 1 to 5; and

and a motor connected to the power conversion device and supplied with the electric power converted by the power conversion device.

7. The drive apparatus according to claim 6,

the power conversion device includes: a 1 st mounting substrate on which the upper arm element of the 1 st inverter and the lower arm element of the 2 nd inverter are mounted; and a 2 nd mounting substrate on which the upper arm element of the 2 nd inverter and the lower arm element of the 1 st inverter are mounted,

in the motor, both the one end and the other end of the winding are connected to one of the 1 st mounting board and the 2 nd mounting board, and both the one end and the other end of the winding penetrate the one mounting board and are connected to the other mounting board.

8. A power steering apparatus includes:

the power conversion device according to any one of claims 1 to 5;

a motor connected to the power conversion device and supplied with the electric power converted by the power conversion device; and

and a power steering mechanism driven by the motor.

Technical Field

The invention relates to a power conversion device, a drive device, and a power steering device.

Background

Conventionally, an inverter drive system is known in which electric power of a motor is converted by two inverters. Further, an inverter drive system is also known in which an inverter is connected to each end of each winding of the motor and power is supplied to each winding independently.

For example, patent document 1 discloses a power conversion device having two inverter units. In patent document 1, a failure of a switching element is detected by a failure detection unit. When the switching element has failed, the on/off operation control of the switching element is switched from the normal-time control to the failure-time control to drive the rotating electric machine (motor) continuously.

Disclosure of Invention

Problems to be solved by the invention

In recent years, it has been required to increase the continuity of power supply by making all or a part of a drive system including a power supply and a control circuit redundant with respect to power supply in a power conversion device, a drive device, and a power steering device. In particular, in the above-described system in which power is supplied to each winding of the motor independently, there is a demand for a configuration in which, when an abnormality occurs in one of the redundant power supplies, the other power supply is used to continue the power supply.

Therefore, an object of the present invention is to provide a power conversion device, a drive device, and a power steering device that can continue power supply using one power source when abnormality occurs in the other power source.

Means for solving the problems

A power conversion device according to an aspect of the present invention includes: a 1 st inverter having an upper arm element and a lower arm element and connected to one end of each phase winding of the motor; a 2 nd inverter having an upper arm element and a lower arm element and connected to the other end opposite to the one end; a 1 st power supply that supplies power to the upper arm element of the 1 st inverter and the lower arm element of the 2 nd inverter; and a 2 nd power supply that supplies power to the upper arm element of the 2 nd inverter and the lower arm element of the 1 st inverter.

In addition, a driving device according to an aspect of the present invention includes: the above-described power conversion device; and a motor connected to the power conversion device and supplied with the electric power converted by the power conversion device.

Further, a power steering apparatus according to an aspect of the present invention includes: the above-described power conversion device; a motor connected to the power conversion device and supplied with the electric power converted by the power conversion device; and a power steering mechanism driven by the motor.

Effects of the invention

According to the present invention, when an abnormality occurs in one of the power supplies, the other power supply can be used to continue the power supply.

Drawings

Fig. 1 is a diagram schematically showing a block structure of a motor drive unit of the present embodiment.

Fig. 2 is a diagram schematically showing a circuit configuration of the motor drive unit of the present embodiment.

Fig. 3 is a diagram showing current values flowing through the coils of the respective phases of the motor at normal times.

Fig. 4a is a diagram showing an example of the current value flowing through each coil of each phase of the motor at the time of an abnormality.

Fig. 4b is a diagram showing a modification of the current value flowing through each coil of each phase of the motor in an abnormal state.

Fig. 5 is a diagram schematically showing the hardware structure of the motor drive unit.

Fig. 6 is a diagram schematically showing the hardware configuration of the 1 st mounting substrate and the 2 nd mounting substrate.

Fig. 7 is a diagram schematically showing the hardware configuration of a mounting substrate according to a modification of the present embodiment.

Fig. 8 is a diagram schematically showing the hardware configuration of a mounting board according to another modification of the present embodiment.

Fig. 9 is a diagram schematically showing the configuration of the power steering apparatus according to the present embodiment.

Detailed Description

Hereinafter, embodiments of the power conversion device, the drive device, and the power steering device according to the present disclosure will be described in detail with reference to the drawings. However, in order to avoid unnecessarily long descriptions below, those skilled in the art will readily understand that excessive detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of substantially the same structure may be omitted.

In the present specification, an embodiment of the present disclosure will be described by taking as an example a power conversion device that converts power from a power supply into power to be supplied to a 3-phase motor having 3-phase (U-phase, V-phase, W-phase) windings (sometimes referred to as "coils"). However, a power conversion device that converts power from a power supply into power to be supplied to an n-phase motor having 4-phase or 5-phase (n is an integer of 4 or more) windings also falls within the scope of the present disclosure.

(Structure of Motor drive Unit 1000)

Fig. 1 is a diagram schematically showing a block structure of a motor drive unit 1000 of the present embodiment. The motor drive unit 1000 includes power supply devices 101 and 102, a motor 200, and control circuits 301 and 302.

In the present specification, a motor drive unit 1000 having a motor 200 as a component will be described. The motor drive unit 1000 having the motor 200 corresponds to an example of the drive device of the present invention. However, the motor drive unit 1000 may be a device for driving the motor 200 without the motor 200 as a component. The motor drive unit 1000 in which the motor 200 is omitted corresponds to an example of the power conversion device of the present invention.

The 1 st power supply device 101 has a 1 st inverter 111, a current sensor 401, and a voltage sensor 411. The 2 nd power supply device 102 has a 2 nd inverter 112, a current sensor 402, and a voltage sensor 412.

The motor drive unit 1000 can convert electric power from a power source ( reference numerals 403 and 404 in fig. 2) into electric power to be supplied to the motor 200 by the two power supply devices 101 and 102. For example, the 1 st and 2 nd inverters 111 and 112 can convert the direct-current power into three-phase alternating-current power that is pseudo sine waves of U-phase, V-phase, and W-phase.

Each inverter 111, 112 has an upper arm 131, 132 and a lower arm 141, 142. The 1 st inverter 111 is connected to one end 210 of each phase coil of the motor 200, and the 2 nd inverter 112 is connected to the other end 220 of each phase coil of the motor 200. In this specification, with respect to "connection" of components (structural elements) to each other, unless otherwise specified, electrical connection is indicated.

The motor 200 is, for example, a three-phase ac motor. The motor 200 has U-phase, V-phase, and W-phase coils. The winding method of the coil is, for example, concentrated winding or distributed winding.

As described in detail later, the control circuits 301 and 302 include microcontrollers 341 and 342. The 1 st control circuit 301 controls the upper arm 131 of the 1 st inverter 111 and the lower arm 142 of the 2 nd inverter 112 based on input signals from the current sensor 401 and the angle sensor 321. The 2 nd control circuit 302 controls the upper arm 132 of the 2 nd inverter 112 and the lower arm 141 of the 1 st inverter 111 based on input signals from the current sensor 402 and the angle sensor 322. As a control method of the power supply devices 101, 102 in the control circuits 301, 302, for example, a control method selected from vector control and Direct Torque Control (DTC) is used.

A specific circuit configuration of the motor drive unit 1000 will be described with reference to fig. 2.

Fig. 2 is a diagram schematically showing a circuit configuration of the motor drive unit 1000 of the present embodiment.

The motor drive unit 1000 includes power sources 403 and 404, coils 103 and 104, a capacitor 105, a 1 st inverter 111, a 2 nd inverter 112, a motor 200, and control circuits 301 and 302.

The 1 st power supply 403 and the 2 nd power supply 404 are power supplies independent from each other. The power supplies 403 and 404 generate a predetermined power supply voltage (for example, 12V). As the power sources 403 and 404, for example, a dc power source is used. However, the power sources 403 and 404 may be AC-DC converters or DC-DC converters, or may be batteries (secondary batteries).

Coils 103 and 104 are provided between power sources 403 and 404 and inverters 111 and 112. The coils 103 and 104 function as noise filters for smoothing high-frequency noise included in voltage waveforms supplied to the inverters 111 and 112. The coils 103 and 104 smooth the high-frequency noise to prevent the high-frequency noise generated in the inverters 111 and 112 from flowing to the power sources 403 and 404. A capacitor 105 is connected to the power supply terminal of each of the inverters 111 and 112. The capacitor 105 is a so-called bypass capacitor, and suppresses voltage ripples. The capacitor 105 is, for example, an electrolytic capacitor, and the capacity and the number of capacitors to be used are appropriately determined in accordance with design specifications and the like.

The 1 st inverter 111 has an upper arm 131 and a lower arm 141, and is connected to one end 210 of each phase coil of the motor 200. The upper arm 131 has three high-side switching elements connected between the power supply and the motor 200, respectively. The lower arm 141 has three low-side switching elements respectively connected between the motor 200 and the ground.

Specifically, one end 210 of the U-phase coil is connected to the high-side switching element 113H and the low-side switching element 113L. One end 210 of the V-phase coil is connected to the high-side switching element 114H and the low-side switching element 114L. One end 210 of the W-phase coil is connected to the high-side switching element 115H and the low-side switching element 115L. As the switching element, for example, a field effect transistor (MOSFET or the like) or an Insulated Gate Bipolar Transistor (IGBT) is used. In addition, when the switching element is an IGBT, a diode (free wheel) is connected in anti-parallel with the switching element.

For example, the 1 st inverter 111 has shunt resistors 113R, 114R, and 115R in each branch as a current sensor 401 (see fig. 1) for detecting a current flowing through each phase winding of the U-phase, the V-phase, and the W-phase. The current sensor 401 includes a current detection circuit (not shown) that detects a current flowing through each shunt resistor. For example, the shunt resistor can be connected between the low- side switching elements 113L, 114L, and 115L and the ground terminal. The shunt resistor has a resistance value of, for example, about 0.5m Ω to 1.0m Ω.

The number of shunt resistors may be other than three. For example, two shunt resistors 113R and 114R, V for the U-phase and V-phase, two shunt resistors 114R and 115R for the W-phase, or two shunt resistors 113R and 115R for the U-phase and W-phase may be used. The number of shunt resistors used and the arrangement of the shunt resistors are appropriately determined in consideration of product cost, design specifications, and the like.

The 2 nd inverter 112 has an upper arm 132 and a lower arm 142, and is connected to the other end 220 of each phase coil of the motor 200. The upper arm 132 has three high-side switching elements connected between the power supply and the motor 200, respectively. The lower arm 142 has three low-side switching elements respectively connected between the motor 200 and the ground.

Specifically, the other end 220 of the U-phase coil is connected to the high-side switching element 116H and the low-side switching element 116L. The other end 220 of the V-phase coil is connected to the high-side switching element 117H and the low-side switching element 117L. The other end 220 of the W-phase coil is connected to the high-side switching element 118H and the low-side switching element 118L. The 2 nd inverter 112 includes, for example, shunt resistors 116R, 117R, and 118R, as in the 1 st inverter 111.

The motor drive unit 1000 has a 1 st system corresponding to one end 210 side of the coil (winding) of the motor 200 and a 2 nd system corresponding to the other end 220 side of the coil (winding) of the motor 200. The 1 st system includes a 1 st power supply 403, a 1 st inverter 111, and a 1 st control circuit 301. The 2 nd system includes a 2 nd power source 404, a 2 nd inverter 112, and a 2 nd control circuit 302.

The target of power supply by the power sources 403 and 404 and the target of control by the control circuits 301 and 302 span both systems.

The 1 st power source 403 supplies power to the upper arm 131 of the 1 st inverter 111 and the lower arm 142 of the 2 nd inverter 112. The 2 nd power source 404 supplies power to the upper arm 132 of the 2 nd inverter 112 and the lower arm 141 of the 1 st inverter 111.

The 1 st control circuit 301 controls the upper arm 131 of the 1 st inverter 111 and the lower arm 142 of the 2 nd inverter 112. The 2 nd control circuit 302 controls the upper arm 132 of the 2 nd inverter 112 and the lower arm 141 of the 1 st inverter 111.

Reference is again made to fig. 1. The control circuits 301 and 302 include, for example, power supply circuits 311 and 312, angle sensors 321 and 322, input circuits 331 and 332, microcontrollers 341 and 342, drive circuits 351 and 352, and ROMs 361 and 362. The control circuits 301 and 302 are connected to the power supply devices 101 and 102. Further, as described above, the control circuits 301 and 302 control the 1 st inverter 111 and the 2 nd inverter 112.

The control circuits 301 and 302 can control a target position (rotation angle), rotation speed, current, and the like of the rotor to realize closed-loop control. The rotation speed is obtained by time-differentiating the rotation angle (rad), for example, and is expressed by the number of rotations (rpm) of the rotor per unit time (e.g., 1 minute). The control circuits 301 and 302 can also control the target motor torque. The control circuits 301 and 302 may have a torque sensor for torque control, but torque control is possible even if the torque sensor is omitted. Instead of the angle sensor, a sensorless algorithm may be provided. The two control circuits 301 and 302 control the motors in synchronization with the rotation of the motors, respectively, to synchronize the control operations with each other.

The power supply circuits 311 and 312 generate DC voltages (e.g., 3V and 5V) necessary for respective blocks in the circuits.

The angle sensors 321, 322 are, for example, resolvers or hall ICs. The angle sensors 321 and 322 can also be realized by a combination of an MR sensor having a Magnetoresistive (MR) element and a sensor magnet. The angle sensors 321, 322 detect the rotation angle of the rotor of the motor 200, and output rotation signals indicating the detected rotation angle to the microcontrollers 341, 342. Depending on the motor control method (e.g., sensorless control), the angle sensors 321 and 322 may be omitted.

The voltage sensors 411 and 412 detect voltages between the phases of the coils of the motor 200, and output the detected voltage values to the input circuits 331 and 332.

The input circuits 331 and 332 receive motor current values (hereinafter referred to as "actual current values") detected by the current sensors 401 and 402 and voltage values detected by the voltage sensors 411 and 412. The input circuits 331, 332 convert the levels of the actual current value and the voltage value into input levels of the microcontrollers 341, 342 as necessary, and output the actual current value and the voltage value to the microcontrollers 341, 342. The input circuits 331 and 332 are analog-digital conversion circuits.

The microcontrollers 341, 342 receive the rotation signals of the rotors detected by the angle sensors 321, 322, and receive the actual current values and voltage values output from the input circuits 331, 332. The microcontrollers 341 and 342 set a target current value based on an actual current value, a rotor rotation signal, and the like, generate PWM signals, and output the generated PWM signals to the drive circuits 351 and 352. For example, the microcontrollers 341 and 342 generate PWM signals for controlling the switching operation (on or off) of the switching elements in the inverters 111 and 112 of the power supply devices 101 and 102.

The microcontrollers 341 and 342 can determine the control method for controlling the 1 st inverter 111 and the 2 nd inverter 112 based on the received voltage value.

The driving circuits 351 and 352 are, for example, gate drivers. The drive circuits 351 and 352 generate control signals (for example, gate control signals) for controlling the switching operation of the switching elements in the 1 st inverter 111 and the 2 nd inverter 112 based on the PWM signals, and supply the generated control signals to the switching elements.

The microcontrollers 341, 342 may also have the function of driving the circuits 351, 352. In this case, the drive circuits 351 and 352 are omitted.

The ROMs 361 and 362 are, for example, writable memory (PROM, for example), rewritable memory (flash memory, for example) or read-only memory. The ROMs 361 and 362 store a control program including a command set for causing the microcontrollers 341 and 342 to control the power supply devices 101 and 102 (mainly the inverters 111 and 112). For example, the control program is temporarily loaded once in a RAM (not shown) at the time of startup.

In the control of the inverters 111 and 112 by the control circuits 301 and 302 (mainly, the microcontrollers 341 and 342), there are normal-time and abnormal-time control.

Hereinafter, a specific example of the operation of the motor drive unit 1000 will be described, and mainly a specific example of the operation of the inverters 111 and 112 will be described.

(control in normal times)

First, a specific example of a normal control method of the inverters 111 and 112 will be described. The normal state is a state in which the two power sources 403 and 404, the two inverters 111 and 112, and the two control circuits 301 and 302 are all operating correctly.

In a normal state, the control circuits 301 and 302 drive the motor 200 by performing three-phase energization control using both the upper arms 131 and 132 and the lower arms 141 and 142 of the 1 st inverter 111 and the 2 nd inverter 112. For example, the control circuits 301 and 302 can perform three-phase energization control by performing switching control of the switching elements of the 1 st inverter 111 and the switching elements of the 2 nd inverter 112 at a duty ratio that varies periodically. The periodic variation of the duty ratio of each of the 1 st inverter 111 and the 2 nd inverter 112 can be switched by the control circuits 301 and 302. The control circuits 301 and 302 may be switched to a cyclic variation in reverse phase (phase difference of 180 °) in the 1 st inverter 111 and the 2 nd inverter 112, for example.

Fig. 3 is a diagram showing the values of currents flowing through the coils of the respective phases of the motor 200 in a normal state.

Fig. 3 illustrates current waveforms (sine waves) obtained by plotting current values flowing through the respective coils of the U-phase, V-phase, and W-phase of the motor 200 when the 1 st inverter 111 and the 2 nd inverter 112 are controlled in accordance with three-phase energization control at normal times. In fig. 3, the horizontal axis represents the motor electrical angle (degrees) and the vertical axis represents the current value (a). I is_pkThe maximum current value (peak current value) of each phase is shown. In addition to the sine wave illustrated in fig. 3, the power supply devices 101 and 102 can drive the motor 200 with a rectangular wave, for example.

Table 1 shows the values of the currents flowing in the terminals of the respective inverters at each electrical angle in the sine wave of fig. 3. Specifically, table 1 shows the inverter 111 and U-phase, V-phase in 1 stThe current value per 30 ° in electrical angle flows at the point where the one ends 210 of the coils of the respective phases and W phase are connected. Table 1 shows current values per 30 ° in electrical angle flowing at a point where the 2 nd inverter 112 is connected to the other end 220 of each of the U-phase, V-phase, and W-phase coils. Here, for the 1 st inverter 111, a direction of current flowing from one end 210 to the other end 220 of the motor 200 is defined as a positive direction. In addition, the 2 nd inverter 112 defines the direction of the current flowing from the other end 220 to the one end 210 of the motor 200 as the positive direction. Therefore, the phase difference between the current of the 1 st inverter 111 and the current of the 2 nd inverter 112 is 180 °. In Table 1, the current value I₁Size of (3)^1/2/2]＊I_pkValue of current I₂Has a size of I_pk/2。

[ Table 1]

At an electrical angle of 0 °, the current in the U-phase coil is "0". When the electrical angle is 0 °, I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil₁The current of I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the W-phase coil₁The current of (2).

When the electrical angle is 30 °, I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the U-phase coil₂The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil_pkThe current of I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the W-phase coil₂The current of (2).

When the electrical angle is 60 °, I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the U-phase coil₁The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil₁The current of (2). At an electrical angle of 60 °, the current in the W-phase coil is "0".

When the electrical angle is 90 °, a current of magnitude I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the U-phase coil_pkCurrent of (2) inverse in the V-phase coilThe flow of the converter 112 to the 1 st inverter 111 is I₂The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil₂The current of (2).

When the electrical angle is 120 °, a current of magnitude I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the U-phase coil₁The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil₁The current of (2). At an electrical angle of 120 °, the current in the V-phase coil is "0".

When the electrical angle is 150 °, a current of magnitude I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the U-phase coil₂The current of I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the V-phase coil₂The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil_pkThe current of (2).

At an electrical angle of 180 °, the current in the U-phase coil is "0". When the electrical angle is 180 °, I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the V-phase coil₁The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil₁The current of (2).

When the electrical angle is 210 °, I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil₂The current of I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the V-phase coil_pkThe current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil₂The current of (2).

When the electrical angle is 240 °, a current of magnitude I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil₁The current of I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the V-phase coil₁The current of (2). At an electrical angle of 240 °, the current in the W-phase coil is "0".

When the electrical angle is 270 °, a current of magnitude I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil_pkThe current of I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the V-phase coil₂In W-phase coilFrom the 1 st inverter 111 to the 2 nd inverter 112 by the flow of I₂The current of (2).

When the electrical angle is 300 °, I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil₁The current of I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the W-phase coil₁The current of (2). At an electrical angle of 300 °, the current in the V-phase coil is "0".

When the electrical angle is 330 °, a current of magnitude I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil₂The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil₂The current of I flows from the 1 st inverter 111 to the 2 nd inverter 112 in the W-phase coil_pkThe current of (2).

In the current waveform shown in fig. 3, the sum of the currents flowing in the three-phase coil when the current direction is considered is "0" at each electrical angle. However, depending on the circuit configuration of the power supply devices 101 and 102, the currents flowing through the three-phase coils are independently controlled. Therefore, the control circuits 301 and 302 can also perform control so that the total of the currents becomes a value other than "0".

(control in an abnormal State)

A specific example of a method for controlling the 1 st inverter 111 and the 2 nd inverter 112 in an abnormal state will be described.

The abnormality is a state in which one or more of the two power sources 403 and 404, the two inverters 111 and 112, and the two control circuits 301 and 302 have failed. In the rough division, the abnormality includes an abnormality of the 1 st system and an abnormality of the 2 nd system. Further, as the abnormality of each system, there are an abnormality caused by a failure of the inverters 111, 112 and an abnormality of a drive system including the power sources 403, 404 and the control circuits 301, 302. The failure of the inverters 111 and 112 includes disconnection, short circuit, failure of the switching element, and the like in the inverter circuit.

The "abnormality of the drive system" includes various abnormal states such as a state in which only the power supplies 403 and 404 are abnormal, only the control circuits 301 and 302 are abnormal, both the power supplies 403 and 404 and the control circuits 301 and 302 are abnormal, and the control circuits 301 and 302 are also stopped in response to the abnormality of the power supplies 403 and 404.

As a control method at the time of an abnormality caused by a failure of the inverters 111 and 112, for example, a control method described in japanese patent application laid-open No. 2014-192950 and the like are used. A control method in the case of an abnormality of the drive system will be described below.

As an example of the abnormality detection, the control circuits 301 and 302 (mainly, the microcontrollers 341 and 342) detect an abnormality in the system on the other side of the two systems, which is opposite to the system to which the control circuit itself belongs, by analyzing the voltage values detected by the voltage sensors 411 and 412. The control circuits 301 and 302 can check the voltages of the upper arms 131 and 132 and the lower arms 141 and 142 under the control of the control circuits 301 and 302 on the other side by the upper arms 131 and 132 and the lower arms 141 and 142 under their own control. Specifically, the upper arms 131 and 132 and the lower arms 141 and 142 connected to each other in one inverter 111 and 112 are controlled by different control circuits 301 and 302. Further, the voltage sensors 411, 412 detect the voltages of the wirings connecting the upper arms 131, 132 and the lower arms 141, 142.

As another example of the abnormality detection, the microcontrollers 341 and 342 can detect an abnormality by analyzing the difference between the actual current value and the target current value of the motor, or the like. However, the control circuits 301 and 302 are not limited to these methods, and a known method related to abnormality detection can be widely used.

When the microcontrollers 341, 342 detect an abnormality, the control circuits 301, 302 switch the control of the inverters 111, 112 from the normal control to the abnormal control. For example, the timing for switching the control from the normal time to the abnormal time is about 10msec to 30msec from the detection of the abnormality.

The control circuits 301 and 302 perform half-wave drive control of the inverters 111 and 112 in the event of an abnormality. In the half-wave drive control, only the upper arms 131, 132 and the lower arms 141, 142, which are controlled by the normal control circuits 301, 302, of the upper arms 131, 132 and the lower arms 141, 142 of the inverters 111, 112 are driven.

For example, when one of the 1 st power supply 403 and the 2 nd power supply 404 malfunctions, the control circuits 301 and 302 drive the 1 st inverter 111 and the 2 nd inverter 112 using the other power supply. As a result, the motor drive unit 1000 can continue the power supply using one of the power sources 403 and 404 when the other power source is abnormal.

Specifically, when the control circuit 301 of the 1 st system detects an abnormality in the drive system of the 2 nd system, electric power is supplied to the motor 200 only by the drive control of the upper arm 131 of the 1 st inverter 111 and the lower arm 142 of the 2 nd inverter 112 by the control circuit 301 of the 1 st system. The control circuit 301 of the 1 st system performs control in accordance with whether or not the operation of the drive system on the 2 nd system side including the 2 nd power supply 404 and the 2 nd control circuit 302 is normal.

In addition, when the control circuit 302 of the 2 nd system detects an abnormality of the drive system of the 1 st system, electric power is supplied to the motor 200 only by the drive control of the upper arm 132 of the 2 nd inverter 112 and the lower arm 141 of the 1 st inverter 111 by the control circuit 302 of the 2 nd system. The control circuit 302 of the 2 nd system performs control in accordance with whether or not the operation of the drive system on the 1 st system side including the 1 st power supply 403 and the 1 st control circuit 301 is normal.

In the 1 st system and the 2 nd system, the control circuits 301 and 302 perform control in accordance with the state of the other side, and thus, even when an abnormality occurs in any one of the 1 st system and the 2 nd system, appropriate drive control can be performed to supply electric power. Fig. 4a is a diagram showing the values of currents flowing through the coils of the respective phases of the motor 200 at the time of an abnormality.

Fig. 4a illustrates current waveforms obtained by plotting current values flowing through the respective coils of the U-phase, V-phase, and W-phase of the motor 200 when the 1 st inverter 111 and the 2 nd inverter 112 are controlled by half-wave drive control at the time of an abnormality. In fig. 4a, the horizontal axis represents the motor electrical angle (degrees) and the vertical axis represents the current value (a). I is_pkThe maximum current value (peak current value) of each phase is shown.

According to the current waveform illustrated in fig. 4a, the output torque of the motor is a constant value. The power supply devices 101 and 102 can also drive the motor 200 using a current waveform other than the current waveform illustrated in fig. 4 a. For example, the power supply devices 101 and 102 can drive the motor 200 using a trapezoidal current waveform as illustrated in fig. 4 b.

Table 2 illustrates current values flowing through the respective coils of the U-phase, V-phase, and W-phase of the motor 200 at each electrical angle in the case where the 1 st inverter 111 and the 2 nd inverter 112 are controlled in accordance with the energization control that can obtain the current waveform shown in fig. 4 a. Specifically, table 2 shows, for example, current values per 30 ° in electrical angle flowing at points where the 2 nd inverter 112 is connected to the other ends 220 of the coils of the U-phase, the V-phase, and the W-phase when an abnormality occurs on the 1 st system side. The current direction is defined as described above.

[ Table 2]

When the electrical angle is 0 °, a current of magnitude I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil₂The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil_pkThe current of (2) is "0" in the V-phase coil.

When the electrical angle is 30 °, I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil₁The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil₁The current of (2) is "0" in the V-phase coil.

When the electrical angle is 60 °, I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil_pkThe current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil₂The current of (2) is "0" in the V-phase coil.

When the electrical angle is 90 °, I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil₁The current of (2) is "0" in the V-phase and W-phase coils.

At an electrical angle of 120 DEGIn the U-phase coil, the current flows from the 2 nd inverter 112 to the 1 st inverter 111 by the magnitude I_pkThe current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil₂The current of (2) is "0" in the W-phase coil.

When the electrical angle is 150 °, a current of magnitude I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil₁The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil₁The current of (2) is "0" in the W-phase coil.

When the electrical angle is 180 °, a current of magnitude I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the U-phase coil₂The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil_pkThe current of (2) is "0" in the W-phase coil.

When the electrical angle is 210 °, I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil₁The current of (2) is "0" in the U-phase and W-phase coils.

When the electrical angle is 240 °, the current is "0" in the U-phase coil, and I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil_pkThe current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil₂The current of (2).

When the electrical angle is 270 °, the current is "0" in the U-phase coil, and I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the V-phase coil₁The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil₁The current of (2).

When the electrical angle is 300 °, the current in the U-phase coil is "0", and the current in the V-phase coil flows from the 2 nd inverter 112 to the 1 st inverter 111 at a magnitude of I₂The current of I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil_pkThe current of (2).

When the electrical angle is 330 °, the current is "0" in the U-phase and V-phase coils, and I flows from the 2 nd inverter 112 to the 1 st inverter 111 in the W-phase coil₁Current of。

(hardware construction of Motor drive Unit 1000)

Next, a hardware configuration of the motor drive unit 1000 will be explained.

Fig. 5 is a diagram schematically showing the hardware configuration of the motor drive unit 1000.

The motor drive unit 1000 includes a 1 st mounting board 1001, a 2 nd mounting board 1002, a housing 1003, connectors 1004 and 1005, and the motor 200 described above as a hardware configuration.

One end 210 and the other end 220 of the coil protrude from the motor 200 and extend toward the mounting substrates 1001, 1002. Both the one end 210 and the other end 220 of the coil are connected to one of the 1 st mounting substrate 1001 and the 2 nd mounting substrate 1002, and both the one end 210 and the other end 220 penetrate the one of the 1 st mounting substrate 1001 and the 2 nd mounting substrate 1002 and are connected to the other mounting substrate. Specifically, both the one end 210 and the other end 220 of the coil are connected to, for example, the 2 nd mounting substrate 1002. Both the one end 210 and the other end 220 of the coil penetrate the 2 nd mounting board 1002 and are connected to the 1 st mounting board 1001.

Substrate surfaces of the 1 st mounting substrate 1001 and the 2 nd mounting substrate 1002 face each other. The rotation axis of the motor 200 extends in a direction facing the substrate surface. The 1 st mounting board 1001, the 2 nd mounting board 1002, and the motor 200 are housed in a case 1003, and are fixed in position with each other.

A connector 1004 connected to a power line from the 1 st power supply 403 is mounted on the 1 st mounting board 1001. A connector 1005 connected to a power supply line from the 2 nd power supply 404 is mounted on the 2 nd mounting board 1002.

Fig. 6 is a diagram schematically showing the hardware configuration of the 1 st mounting substrate 1001 and the 2 nd mounting substrate 1002.

Upper arm 131 of 1 st inverter 111 and lower arm 142 of 2 nd inverter 112 are mounted on 1 st mounting board 1001. Further, the upper arm 132 of the 2 nd inverter 112 and the lower arm 141 of the 1 st inverter 111 are mounted on the 2 nd mounting board 1002. By distributing the components to the two mounting boards 1001 and 1002 in this manner, the wiring of the upper arms 131 and 132 and the lower arms 141 and 142 to the one end 210 and the other end 220 of the coil can be simplified, and efficient component arrangement can be realized.

The 1 st control circuit 301 may be mounted on the 1 st mounting board 1001. The 2 nd control circuit 302 may be mounted on the 2 nd mounting board 1002. When the control circuits 301 and 302 and the elements to be controlled by the control circuits 301 and 302 are mounted on the same mounting board, the control wiring is housed in the board. This enables efficient element arrangement.

The upper arm 131 on the 1 st mounting substrate 1001 and the lower arm 141 on the 2 nd mounting substrate 1002 may be mounted at positions overlapping each other when viewed in a direction in which the 1 st mounting substrate 1001 and the 2 nd mounting substrate 1002 face each other. The lower arm 142 on the 1 st mounting board 1001 and the upper arm 132 on the 2 nd mounting board 1002 may be mounted at positions overlapping each other when viewed in a direction in which the 1 st mounting board 1001 and the 2 nd mounting board 1002 face each other. With such a circuit arrangement, efficient element arrangement that effectively utilizes the arrangement area on the mounting substrates 1001, 1002 can be realized.

When viewed in a direction in which the 1 st mounting substrate 1001 and the 2 nd mounting substrate 1002 face each other, the upper arm 131 on the 1 st mounting substrate 1001 and the upper arm 132 on the 2 nd mounting substrate 1002 may be arranged symmetrically to each other. Further, when viewed in a direction in which the 1 st mounting board 1001 and the 2 nd mounting board 1002 face each other, the lower arm 142 on the 1 st mounting board 1001 and the lower arm 141 on the 2 nd mounting board 1002 may be arranged symmetrically to each other. With such a symmetrical arrangement, a substrate design can be shared by the two mounting substrates 1001 and 1002.

(modification example)

Fig. 7 is a diagram schematically showing the hardware configuration of a mounting substrate according to a modification of the present embodiment.

In the modification shown in fig. 7, one double-sided mounting board 1006 is provided. An upper arm 131 of the 1 st inverter 111 and a lower arm 142 of the 2 nd inverter 112 are mounted on one of the front and back surfaces of the double-sided mounting board 1006. An upper arm 132 of the 2 nd inverter 112 and a lower arm 141 of the 1 st inverter 111 are mounted on the other surface opposite to the one surface. By distributing the components on both the front and back surfaces of the double-sided mounting board 1006, the wiring of the upper arms 131 and 132 and the lower arms 141 and 142 to the one end 210 and the other end 220 of the coil can be simplified, and efficient component arrangement can be realized.

The 1 st control circuit 301 may be mounted on one of the front and back surfaces. A 2 nd control circuit 302 may also be mounted on the other side. When the control circuits 301 and 302 and the elements to be controlled by the control circuits 301 and 302 are mounted on the same substrate surface, the control wiring is divided into one surface side and the other surface side, and thus efficient element arrangement can be realized.

In the specific circuit configurations on both the front and back surfaces of the double-sided mounting substrate 1006, the circuit configuration on one surface is, for example, the same as that on the 1 st mounting substrate 1001 shown in fig. 6, and the circuit configuration on the other surface is, for example, the same as that on the 2 nd mounting substrate 1002 shown in fig. 6. Therefore, efficient element arrangement of wiring paths to the one end 210 and the other end 220 of the coil can be simplified, and the front and back surfaces of the double-sided mounting board 1006 can be designed to share the board.

Fig. 8 is a diagram schematically showing the hardware configuration of a mounting board according to another modification of the present embodiment.

In the hardware configuration shown in fig. 8, a 3 rd mounting substrate 1007 is provided in addition to the 1 st mounting substrate 1001 and the 2 nd mounting substrate 1002. The 3 rd mounting substrate 1007 is located between the 1 st mounting substrate 1001 and the 2 nd mounting substrate 1002, for example. Further, for example, the control circuits 301 and 302 are mounted on the 3 rd mounting board 1007, and the upper arms 131 and 132 and the lower arms 141 and 142 of the inverters 111 and 112 are mounted on the 1 st mounting board 1001 and the 2 nd mounting board 1002, for example, in the same manner as the hardware configuration shown in fig. 6. With such a hardware configuration, the power circuit is separated from the control circuit, and therefore, safety can be improved and power supply wiring can be simplified.

(embodiment of Power steering apparatus)

A vehicle such as an automobile generally has a power steering device. The power steering apparatus generates an assist torque for assisting a steering torque of a steering system generated by a driver operating a steering wheel. The assist torque is generated by the assist torque mechanism, and the operation load of the driver can be reduced. For example, the assist torque mechanism is constituted by a steering torque sensor, an ECU, a motor, a speed reduction mechanism, and the like. The steering torque sensor detects a steering torque in the steering system. The ECU generates a drive signal based on a detection signal of the steering torque sensor. The motor generates an assist torque corresponding to the steering torque in response to the drive signal, and transmits the assist torque to the steering system via the speed reduction mechanism.

The motor drive unit 1000 of the above embodiment is preferably used for a power steering apparatus. Fig. 9 is a diagram schematically showing the configuration of a power steering device 2000 according to the present embodiment.

The electric power steering apparatus 2000 has a steering system 520 and an assist torque mechanism 540.

The steering system 520 includes, for example, a steering wheel 521, a steering shaft 522 (also referred to as a "steering column"), universal joints 523A and 523B, and a rotary shaft 524 (also referred to as a "pinion shaft" or an "input shaft").

The steering system 520 includes, for example, a rack and pinion mechanism 525, a rack shaft 526, left and right ball joints 552A and 552B, tie rods 527A and 527B, knuckles 528A and 528B, and left and right steered wheels (e.g., left and right front wheels) 529A and 529B.

The steering wheel 521 is coupled to the rotating shaft 524 via the steering shaft 522 and the universal joints 523A and 523B. The rotary shaft 524 is coupled to a rack shaft 526 via a rack and pinion mechanism 525. The rack and pinion mechanism 525 includes a pinion 531 provided on the rotating shaft 524 and a rack 532 provided on the rack shaft 526. The right end of the rack shaft 526 is connected to the right steered wheel 529A via a ball joint 552A, a tie rod 527A, and a knuckle 528A in this order. Similarly to the right side, the left end of the rack shaft 526 is coupled to the left steered wheel 529B via a ball joint 552B, a tie rod 527B, and a knuckle 528B in this order. Here, the right and left sides coincide with the right and left sides, respectively, as viewed from the driver seated in the seat.

According to the steering system 520, a steering torque is generated by the driver operating the steering wheel 521, and is transmitted to the left and right steering wheels 529A and 529B via the rack and pinion mechanism 525. This allows the driver to operate the left and right steering wheels 529A and 529B.

The assist torque mechanism 540 includes, for example, a steering torque sensor 541, an ECU 542, a motor 543, a reduction mechanism 544, and a power supply device 545. The assist torque mechanism 540 applies assist torque to the steering system 520 from the steering wheel 521 to the left and right steered wheels 529A and 529B. In addition, the assist torque is sometimes referred to as "additional torque".

As the ECU 542, for example, the control circuits 301 and 302 shown in fig. 1 and the like are used. As the power supply device 545, for example, the power supply devices 101 and 102 shown in fig. 1 and the like are used. As the motor 543, for example, the motor 200 shown in fig. 1 and the like is used. When the ECU 542, the motor 543, and the power supply device 545 constitute what is generally called an "electromechanical integrated motor", it is preferable to use, for example, a motor drive unit 1000 having a hardware configuration shown in fig. 5 as this unit. The mechanism constituted by the elements other than the ECU 542, the motor 543, and the power supply device 545 among the elements shown in fig. 9 corresponds to an example of the power steering mechanism driven by the motor 543.

The steering torque sensor 541 detects a steering torque of the steering system 520 applied from the steering wheel 521. The ECU 542 generates a drive signal for driving the motor 543 based on a detection signal (hereinafter referred to as "torque signal") from the steering torque sensor 541. The motor 543 generates an assist torque corresponding to the steering torque based on the drive signal. The assist torque is transmitted to the rotary shaft 524 of the steering system 520 via the speed reduction mechanism 544. The reduction mechanism 544 is, for example, a worm gear mechanism. The assist torque is further transmitted from the rotating shaft 524 to the rack and pinion mechanism 525.

The power steering apparatus 2000 is classified into a pinion assist type, a rack assist type, a column assist type, and the like according to a portion to which assist torque is applied to the steering system 520. Fig. 9 shows a pinion assist type power steering apparatus 2000. However, the power steering device 2000 is also applicable to a rack assist type, a column assist type, and the like.

Not only the torque signal but also, for example, a vehicle speed signal can be input to the ECU 542. The microcontroller of the ECU 542 can vector-control the motor 543 based on the torque signal, the vehicle speed signal, and the like.

The ECU 542 sets a target current value based on at least the torque signal. Preferably, the ECU 542 sets the target current value in consideration of a vehicle speed signal detected by a vehicle speed sensor, and further, in consideration of a rotation signal of the rotor detected by an angle sensor. The ECU 542 can control a drive signal, i.e., a drive current, of the motor 543 so that an actual current value detected by a current sensor (see fig. 1) matches a target current value.

According to the power steering apparatus 2000, the left and right steered wheels 529A and 529B can be operated by the rack shaft 526 using a composite torque obtained by adding the steering torque of the driver to the assist torque of the motor 543. In particular, by using the motor drive unit 1000 of the above-described embodiment in the above-described mechatronic motor, it is possible to perform appropriate current control both in a normal state and in an abnormal state. As a result, the assist force assist of the power steering apparatus is continued both in the normal state and in the abnormal state.

Description of the reference symbols

101. 102: a power supply device; 111: 1 st inverter; 112: a 2 nd inverter; 131. 132: an upper arm; 141. 142: a lower arm; 200: a motor; 301. 302: a control circuit; 311. 312: a power supply circuit; 321. 322: an angle sensor; 331. 332: an input circuit; 341. 342: a microcontroller; 351. 352: a drive circuit; 361. 362: a ROM; 401. 402, a step of: a current sensor; 403. 404: a power source; 411. 412: a voltage sensor; 1000: a motor drive unit; 1001. 1002, 1007: a mounting substrate; 1006: a double-sided mounting substrate; 2000: provided is a power steering device.