阅读说明：本技术 马达控制装置 (Motor control device ) 是由 初田匡之 奥畑佳久 于 2018-11-15 设计创作，主要内容包括：在马达控制装置具有：逆变器电路,其向马达提供驱动电压；以及控制部,其在从外部提供的扭矩指示值不到规定的阈值的情况下,使来自第1电源的电源电压提供给所述逆变器电路,在所述扭矩指示值为所述规定的阈值以上的情况下,使来自第2电源的电源电压提供给所述逆变器电路,该第1电源提供第1电源电压,该第2电源提供比第1电源电压高的电源电压。(The motor control device includes: an inverter circuit that supplies a drive voltage to the motor; and a control unit that supplies a power supply voltage from a 1 st power supply to the inverter circuit when a torque instruction value supplied from an external source is less than a predetermined threshold value, and supplies a power supply voltage from a 2 nd power supply to the inverter circuit when the torque instruction value is equal to or greater than the predetermined threshold value, the 1 st power supply supplying the 1 st power supply voltage, the 2 nd power supply supplying a power supply voltage higher than the 1 st power supply voltage.)

1. A motor control device is characterized in that,

the motor control device comprises:

an inverter circuit that supplies a drive voltage to the motor; and

and a control unit that supplies a power supply voltage from a 1 st power supply to the inverter circuit when a torque instruction value supplied from an external source is less than a predetermined threshold value, and supplies a power supply voltage from a 2 nd power supply to the inverter circuit when the torque instruction value is equal to or more than the predetermined threshold value, the 1 st power supply supplying the 1 st power supply voltage, the 2 nd power supply supplying a power supply voltage higher than the 1 st power supply voltage.

2. The motor control apparatus according to claim 1,

the capacity of the 2 nd power supply is less than or equal to one twentieth of the capacity of the 1 st power supply.

3. The motor control device according to claim 1 or 2,

the motor control device further has an input section that inputs information indicating a threshold value,

the control unit sets the predetermined threshold value based on information indicating the threshold value.

4. The motor control apparatus according to any one of claims 1 to 3,

the control unit changes the predetermined threshold value in accordance with a variation in the torque instruction value.

5. The motor control apparatus according to any one of claims 1 to 4,

the motor control device includes a power conversion unit that performs power conversion from an arbitrary power source to another power source according to a charging state of the 2 nd power source.

6. The motor control apparatus according to claim 5,

the power conversion unit has a bidirectional DCDC converter.

Technical Field

The present invention relates to a motor control device for controlling driving of a motor.

Background

A technique is known in which driving power of a motor as motive power of a vehicle or the like is controlled using an inverter circuit.

For example, patent document 1 discloses a power conversion system having a plurality of batteries, and discloses a parallel boosting technique for boosting voltages in parallel in the plurality of batteries.

Disclosure of Invention

Problems to be solved by the invention

However, in the technique disclosed in patent document 1, since a booster circuit is required for each of the plurality of batteries, the entire system of the motor is increased in size.

In view of the above-described problems, an object of the present invention is to provide a motor control device capable of supplying an appropriate power supply voltage corresponding to a torque instruction value to an inverter circuit and contributing to downsizing of a motor.

Means for solving the problems

In order to solve the above problem, according to one aspect of the present invention, there is provided a motor control device including: an inverter circuit that supplies a drive voltage to the motor; and a control unit that supplies a power supply voltage from a 1 st power supply to the inverter circuit when a torque instruction value supplied from an external source is less than a predetermined threshold value, and supplies a power supply voltage from a 2 nd power supply to the inverter circuit when the torque instruction value is equal to or greater than the predetermined threshold value, the 1 st power supply supplying the 1 st power supply voltage, the 2 nd power supply supplying a power supply voltage higher than the 1 st power supply voltage.

Effects of the invention

According to the present invention having the above configuration, the power supply voltage supplied to the inverter circuit is changed depending on whether or not the torque instruction value is less than the predetermined threshold value, whereby an appropriate power supply voltage corresponding to the torque instruction value can be supplied to the inverter circuit, and a booster circuit or the like does not need to be provided, and therefore, it is possible to contribute to downsizing of the motor.

Drawings

Fig. 1 is a block diagram showing a configuration example of a motor control device according to embodiment 1 of the present invention.

Fig. 2 is a diagram showing a relationship among power consumption of the motor, a rotation speed N of the motor, and a torque T.

Fig. 3 is a flowchart showing an example of switching control of the battery.

Fig. 4 is a flowchart showing an example of power conversion control between batteries.

Fig. 5 is a diagram showing an example of a change in the state of charge of the battery.

Fig. 6 is a flowchart showing an example of power conversion control between batteries.

Fig. 7 is a diagram showing an example of a change in the state of charge of the battery.

Fig. 8 is a flowchart showing an example of power conversion control between batteries.

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

< embodiment >

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

The motor control device comprises: a motor controller 2 that controls a motor 30 that outputs driving force to a vehicle or the like; a VCU (Vehicle Control Unit) 3 that outputs a torque command (torque instruction value) according to a state of the Vehicle; and an inverter 21 that generates a drive voltage in accordance with control from the motor controller 2. In addition, the motor control device has a switching circuit 50, which is provided with a switching circuit50 supply the inverter 21 by switching the power supply voltages of the battery 4a and the battery 4b in accordance with the power supply voltage (request voltage) requested from the inverter 21, wherein the battery 4a supplies the direct-current power supply voltage (1 st power supply voltage V)_BATT1) The battery 4b provides a voltage V higher than the 1 st power supply voltage_BATT1High 2 nd supply voltage V_BATT2. Since the battery 4b is used for a short time when the torque instruction value is equal to or greater than the predetermined threshold value during acceleration or the like, the capacity of the battery 4b is, for example, one twentieth or less of that of the battery 4a used during normal running.

The motor control device further includes: a battery controller 5 that controls the State of Charge (SoC) of the batteries 4a and 4 b; a DCDC converter (power converter) 40 that performs power conversion between the battery 4a and the battery 4b in accordance with control from the battery controller 5; and a temperature sensor 6 that detects the temperature around the motor 30, the temperature of the refrigerant that cools the motor 30, and the like. The DCDC converter unit 40 includes a bidirectional DCDC converter capable of performing both step-down and step-up operations.

The motor 30 is constituted by, for example, a brushless motor having a rotor provided to be rotatable about a rotation shaft having an output end, a stator having field coils 31u, 31v, 31w and the like that generate a magnetic field by a drive current corresponding to a drive voltage of three phases, and a housing that houses the rotor, the stator, and the like. A permanent magnet is attached to a rotor that rotates around a rotation shaft of the rotor in accordance with a magnetic field generated by an excitation coil, and a driving force is output from one end (output end) of the rotation shaft.

The motor 30 is provided with a position sensor 32 for detecting the angle of the rotor and a temperature sensor 33 for detecting the temperature of the motor 30. The position sensor 32 includes, for example, magnetic sensors such as 3 hall elements arranged around the rotor at intervals of 120 ° to detect the magnetism of the rotor, and the position sensor 32 detects the angle of the rotor. The angle of the rotor may be detected by another member such as a rotary encoder. The temperature sensor 33 has a temperature detection element such as a thermistor, detects the temperature of the motor 30 such as an excitation coil, and supplies the detected temperature to the inverter 21.

The VCU 3 generates a torque command (torque instruction value) indicating a value of a required torque based on a current throttle opening, a vehicle speed, an acceleration at the time of acceleration or deceleration, or other vehicle state, and supplies the torque command to the motor controller 2. The motor controller 2 controls the operation of the inverter 21 based on the torque instruction value.

The inverter 21 includes: a control unit 21b that controls the operation of the entire inverter 21 according to control from the motor controller 2; an Insulated Gate Bipolar Transistor (IGBT) module 21a that generates three-phase drive voltages by switching a voltage V supplied from the switching circuit 50 in accordance with an instruction from the control unit 21 b; and a temperature sensor 21c that detects the temperature of the IGBT21a and the like. The IGBT21a has 3 sets of 6 switching elements (IGBT elements) to generate a drive voltage of three phases. In place of the IGBT element, a switching element such as a MOSFET (Metal oxide semiconductor Field Effect Transistor) may be used.

The control unit 21b detects the angle of the rotor based on the detection voltage of the position sensor 32, for example. The control unit 21b detects the rotation speed of the motor 30 based on the voltage detected by the position sensor 32. Alternatively, the rotation speed of the motor may be detected by a sensor different from the position sensor 32.

The control section 21b calculates necessary electric power required to drive the motor based on the control from the motor controller 2 and the detected rotation speed of the motor 30. The relationship between the rotation speed N and the torque T of the motor 30 changes according to the power consumption of the motor 30 as shown in fig. 2, for example. The relationship between the rotation speed N and the torque T of the motor 30 is, for example, as indicated by a solid line in fig. 2 when the power consumption is 80kW, and as indicated by a broken line when the power consumption is 120 kW. Therefore, the control unit 21b calculates, as the necessary electric power, power consumption that can obtain the required torque from the control from the motor controller 2 and the rotation speed of the motor 30 based on such a relationship.

The control unit 21b controls the operation of the inverter 21 based on the calculated necessary power. Specifically, when the necessary power is less than a predetermined thresholdWhen the value is equal, the control unit 21b supplies the power supply voltage V of the battery 4a to the inverter 21_BATT1Provides the switching circuit 50 with the requested voltage. When the required power is equal to or higher than the predetermined threshold, the control unit 21b supplies the inverter 21 with the power supply voltage V of the battery 4b_BATT2Provides the switching circuit 50 with the requested voltage. That is, the control unit 21b controls the operation of the switching circuit 50 so that the power supply voltage of any of the battery 4a and the battery 4b is supplied to the inverter 21, based on the necessary electric power calculated based on the control corresponding to the torque instruction value and the like from the motor controller 2. Since the necessary electric power is a value corresponding to the torque instruction value, in other words, the control unit 21b controls the operation of the switching circuit 50 so that an appropriate power supply voltage is supplied to the inverter 21, depending on whether or not the torque instruction value is less than a predetermined threshold value.

The switching circuit 50 includes a controller 51 that controls the operation of the entire switching circuit 50, a switching element Tr11 connected to the battery 4b, a regeneration diode D11 connected to the switching element Tr11, switching elements Tr21 and Tr22 connected to the battery 4a, a regeneration diode D21 connected to the switching element Tr21, and a regeneration diode D22 connected to the switching element Tr 22. In fig. 1, the switching elements Tr11, Tr21, and Tr22 are represented as IGBT elements, but switching elements such as MOSFETs may be used. The regeneration diodes D11, D21, and D22 are provided to supply the electric power supplied from the motor 30 via the inverter 21 to the batteries 4a and 4b during deceleration or the like.

When the power supply voltage V of the battery 4a is supplied to the inverter 21_BATT1At this time, the controller 51 turns off the switching element Tr11 and turns on the switching elements Tr21 and Tr 22. In addition, the power supply voltage V of the battery 4b is supplied to the inverter 21_BATT2At this time, the controller 51 turns on the switching element Tr11 and turns off the switching elements Tr21 and Tr 22.

The control unit 21b calculates the current value I from the necessary power obtained as described above and the power supply voltage from the switching circuit 50. Then, the control unit 21b controls the switching of each switching element of the IGBT21a based on the detected rotation angle of the rotor and the calculated current value I to generate three-phase (U-phase, V-phase, and W-phase) drive voltages (drive signals). For example, in the case of sinusoidal drive, the drive voltage is generated by performing PWM (Pulse Width Modulation) control so that an effective value (hereinafter, simply referred to as a current value) of the drive current flowing through the exciting coils 31u, 31v, and 31w of the motor 30 becomes the calculated current value I. Specifically, the control unit 21b changes the PWM modulation degree according to the current value I.

The drive voltage generated by the IGBT21a is supplied to the field coils 31u, 31v, and 31w of the stator of the motor 30, a drive current corresponding to the drive voltage flows through the field coils, and a torque is generated in the rotor by the interaction between the magnetic field generated by the field coils and the permanent magnets of the rotor. The torque is output to the outside via the output end of the rotor.

(Battery switching control)

Fig. 3 is a flowchart showing a control process of the motor in the motor control device. The control unit 21b obtains necessary power obtained by control corresponding to a torque instruction value or the like from the motor controller 2, and controls the operation of the switching circuit 50 so that the power supply voltage of any of the battery 4a and the battery 4b is supplied to the inverter 21, depending on whether or not the necessary power is less than a predetermined threshold value. As described above, since the required electric power is a value corresponding to the torque instruction value, the following description will be made: the control unit 21b controls the operation of the switching circuit 50 so that the power supply voltage of any of the battery 4a and the battery 4b is supplied to the inverter 21, based on whether or not the torque instruction value is less than a predetermined threshold value.

First, the control unit 21b supplies the power supply voltage V of the battery 4a to the switching circuit 50_BATT1As the requested voltage. Accordingly, the controller 51 turns off the switching element Tr11 and turns on the switching elements Tr21 and Tr22 (S1). Thereby, the power supply voltage V of the battery 4a is adjusted_BATT1Is supplied to the inverter 21.

Next, the control section 21b determines the torque instruction value TAnd (S2) whether or not the threshold value is not less than a predetermined threshold value Tth. If the torque instruction value T is less than the predetermined threshold value Tth, the control unit 21b continues the operation of S2 (monitoring the torque instruction value). If the torque instruction value T is not less than a predetermined threshold value Tth, the control section 21b supplies the power supply voltage V of the battery 4b to the switching circuit 50_BATT2As the requested voltage. Accordingly, the controller 51 turns on the switching element Tr11 and turns off the switching elements Tr21 and Tr22 (S3). Thereby, the power supply voltage V of the battery 4b is adjusted_BATT2Is supplied to the inverter 21.

Then, the control unit 21b determines whether or not the torque instruction value T is less than a predetermined threshold value Tth (S4). If the torque instruction value T is less than the predetermined threshold value Tth, the control unit 21b returns to S1. If the torque instruction value T is equal to or greater than the predetermined threshold value Tth, the control unit 21b continues the operation of S4 (monitoring the torque instruction value).

By performing the control as described above, the power supply voltage supplied to the inverter 21 can be appropriately changed depending on whether or not the torque instruction value is less than the predetermined threshold value. Thus, for example, when a torque is required during acceleration and the torque instruction value is equal to or greater than a predetermined threshold value, the inverter 21 is supplied with the power supply voltage of the battery 4b having a higher power supply voltage than the battery 4a, and the necessary power required to drive the motor 30 can be increased. Further, since the battery 4a and the battery 4b are switched to supply the power supply voltage, it is not necessary to provide a booster circuit or the like, and it is possible to contribute to downsizing of the motor.

The predetermined threshold value Tth may be set in advance, but may be set in response to an input from a user. For example, an input unit such as a switch for a user to input an instruction (information indicating a threshold value) of the user to place importance on acceleration, power consumption, and the like is provided, and the control unit 21b sets the threshold value Tth in accordance with the instruction from the user. This enables coping with a plurality of traveling situations corresponding to the instruction of the user. The control unit 21b may change the threshold value Tth in accordance with a change in the torque instruction value (a change in the required power). For example, when the traveling load is higher than that in traveling on a flat ground or the like, such as traveling on a mountain road or an expressway, the reaction can be improved by lowering the threshold value Tth.

(electric Power conversion control)

In addition, in this motor control device, power is converted from one of the batteries to the other battery according to the State of charge (SoC) of the batteries 4a and 4 b. The battery 4b is used for acceleration or the like, but has a smaller capacity (for example, about one twentieth) than the battery 4a, and therefore, may be insufficiently charged when acceleration or the like ends. Therefore, the battery controller 5 monitors the state of charge of the battery 4b, and when the state of charge (SoC2) of the battery 4b becomes less than a predetermined threshold value (Th1, for example, 80%), the DCDC converter 40 boosts the power supply voltage of the battery 4a to charge the battery 4 b.

Specifically, for example, as shown in fig. 4, the battery controller 5 determines whether or not the state of charge SoC2 of the battery 4b becomes less than the threshold Th1 in a state where the charging of the battery 4b is stopped (S11) (S12). When the state of charge SoC2 of the battery 4b becomes less than the threshold Th1, the battery controller 5 boosts the power supply voltage of the battery 4a by the DCDC converter unit 40 to charge the battery 4b (S13). If the state of charge SoC2 of the battery 4b is equal to or greater than the threshold Th1, the battery controller 5 continues the state in which charging is stopped (S11).

While the battery 4b is being charged, the battery controller 5 determines whether or not the state of charge SoC2 of the battery 4b is equal to or greater than a threshold Th1 (S14). If the state of charge SoC2 of the battery 4b is less than the threshold Th1, the battery controller 5 continues the charging of the battery 4b (S13). If the state of charge SoC2 of the battery 4b is equal to or greater than the threshold Th1, the battery controller 5 stops charging of the battery 4b (S11).

By performing the above control, the state of charge SoC2 of the battery 4b can be appropriately managed.

For example, as shown in fig. 5, when the power supply voltage of the battery 4b is supplied to the inverter 21 by acceleration or the like during a period from time t1 to t2, the state of charge SoC2 of the battery 4b decreases, but when the acceleration or the like ends, the battery 4b is charged from the battery 4a via the DCDC conversion unit 40 under the control of the battery controller 5, and therefore, the state of charge SoC2 of the battery 4b is restored to the threshold Th1(t 3).

When the power supply voltage of the battery 4b is supplied to the inverter 21, the electric power supplied from the motor 30 via the inverter 21 is supplied to the battery 4b via the regenerative diode D11 during deceleration or the like, and therefore, the battery may be overcharged (may not be charged by regeneration) depending on a running state or the like. Therefore, in this motor control device, the battery controller 5 monitors the state of charge of the battery 4b, and when the state of charge (SoC2) of the battery 4b becomes equal to or greater than a predetermined threshold value (Th2, for example, 95%), the DCDC converter 40 lowers the power supply voltage of the battery 4b, thereby charging the battery 4 a.

Specifically, for example, as shown in fig. 6, the battery controller 5 determines whether or not the state of charge SoC2 of the battery 4b is equal to or greater than the threshold Th2 in a state where the charging of the battery 4a is stopped (S21) (S22). When the state of charge SoC2 of the battery 4b is equal to or greater than the threshold Th2, the battery controller 5 lowers the power supply voltage of the battery 4b by the DCDC converter unit 40 to charge the battery 4a (S23). If the state of charge SoC2 of the battery 4b is less than the threshold Th2, the battery controller 5 continues the state of stopping charging (S21).

While the charging of the battery 4a is being performed, the battery controller 5 determines whether the state of charge SoC2 of the battery 4b becomes less than the threshold Th1 (S24). If the state of charge SoC2 of the battery 4b is equal to or greater than the threshold Th1, the battery controller 5 continues charging of the battery 4a (S23). If the state of charge SoC2 of the battery 4b becomes less than the threshold Th1, the battery controller 5 stops charging of the battery 4a (S21).

By performing the above control, the state of charge SoC2 of the battery 4b can be appropriately managed.

For example, as shown in fig. 7, after the state of charge SoC2 of the battery 4b decreases due to acceleration or the like during a period from time t11 to t12, the state of charge SoC2 of the battery 4b is recovered by regeneration, and when the state of charge SoC2 of the battery 4b becomes equal to or greater than the threshold Th2 at time t13, the battery controller 5 lowers the power supply voltage of the battery 4b by the DCDC converter 40, and charges the battery 4 a. Then, when the state of charge SoC2 of the battery 4b is less than the threshold Th1 at time t14, the battery controller 5 stops charging of the battery 4 a.

The control shown in fig. 4 and the power conversion control shown in fig. 6 can be performed simultaneously as shown in fig. 8, for example. When the state of charge SoC2 of the battery 4b is less than the threshold Th1, the battery 4b is charged by the processing of S33 to S34, and when the state of charge SoC2 of the battery 4b is equal to or greater than the threshold Th2, the battery 4a is charged by the processing of S36 to S37. By performing such power conversion, the state of charge SoC2 of the battery 4b can be appropriately managed. By performing such management, it is not necessary to excessively increase the capacity of the battery 4b, and it is possible to contribute to downsizing of the entire system such as a vehicle.

< modification example >

In the above-described embodiment, the drive voltage of the motor 30 is generated by sine wave drive, but instead of sine wave drive, the drive voltage may be generated by rectangular wave drive. In the above-described embodiment, the case where the drive control of the brushless motor is performed has been described, but the present invention is also applicable to the case where the drive control of a three-phase synchronous motor or the like is performed using an inverter.

The present application claims priority of japanese patent application No. 2017-252407, which is a japanese application filed on 27/12/2017, and the entire contents of the description described in the japanese application are cited.

Description of the reference symbols

2: a motor controller; 3: a VCU; 4a, 4 b: a battery; 5: a battery controller; 6. 21c, 33: a temperature sensor; 21: an inverter; 21 a: an IGBT; 21 b: a control unit; 30: a motor; 31u, 31v, 31 w: a field coil; 32: a position sensor; 40: a DCDC conversion unit; 50: a switching circuit; 51: a control unit.