JP2019080455A - Motor control device - Google Patents

Abstract

To suppress the fluctuation of a motor current when advance angle control is performed.SOLUTION: A motor control device includes a rotation speed detection unit that detects the rotation speed of a motor, a storage unit that stores an advance angle table in which the rotation speed of the motor and an advance angle value of energization timing of the motor are associated with each other, and a control unit that reads the advance angle value from the advance angle table on the basis of the rotation speed of the motor detected by the rotation speed detection unit, and controls drive of the motor by energizing the motor according to the read advance angle value, and the advance angle table has a first range in which data of the advance angle value is set finely and a second range in which the advance angle value is set roughly in the range of the rotation speed of the motor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor control device.

  The following Patent Document 1 discloses a motor control device that performs advance angle control for advancing an energization timing for energizing a motor to an advance angle side. Specifically, this motor control device has an advance angle table in which an advance angle value is set for each fixed number of revolutions, and based on the detected number of revolutions of the motor, an optimal advance is made from the advance angle table. The angle value is acquired, and the lead angle control is executed with the acquired lead angle value.

International Publication No. 2012/132231

  However, depending on the number of revolutions of the motor, there is a region where the amount of change in motor current (current flowing through the motor) relative to the amount of change in the advance value is large. In patent document 1, although between the point of an advance angle table is interpolated by calculation, there exists a subject to which processing takes time. In addition, when control is performed to switch the advance angle value as flux-weakening control while the motor is rotating at high speed, the motor current may greatly fluctuate, and it may take time until the motor rotation speed is stabilized.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a motor control device capable of suppressing fluctuation of a motor current when performing advance angle control.

  One aspect of the present invention is a motor control device that controls driving of a motor, and includes a rotation number detection unit that detects the rotation number of the motor, the rotation number of the motor, and an advancing angle of energization timing to the motor. The lead angle value read out from the lead angle table based on a storage unit storing a lead angle table associated with a value, and the number of rotations of the motor detected by the rotation number detection unit, and the lead angle read out And a control unit that controls driving of the motor by energizing the motor according to a value, and the advance angle table is finely set to the data of the advance angle value in the range of the number of rotations of the motor. The motor control device is characterized by having a first range and a second range in which the advance value is roughly set.

  One aspect of the present invention is the motor control device described above, wherein the first range is a range in which the rate of change of the current flowing through the motor with respect to the advance value is a predetermined value or more.

  One aspect of the present invention is the motor control device described above, wherein the first range is a middle rotation range of the motor, and the second range is a low rotation range and a high rotation range of the motor. It is.

  As described above, according to the present invention, it is possible to suppress the fluctuation of the motor current when performing the lead angle control.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of schematic structure of the electrically-driven oil pump 1 which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the drive device 8 which concerns on one Embodiment of this invention. It is a figure explaining the advance angle table which concerns on one Embodiment of this invention. It is a figure which shows the flow of operation | movement of advance angle control in the motor control apparatus 12 which concerns on one Embodiment of this invention. It is a figure explaining the conventional advance angle table.

  Hereinafter, a motor control device according to an embodiment of the present invention will be described using the drawings.

  FIG. 1 is a view showing an example of a schematic configuration of an electric oil pump 1 according to an embodiment of the present invention. A motor control device according to an embodiment of the present invention controls driving of a motor used as a driving source of the electric oil pump 1.

  The electric oil pump 1 is used, for example, as a hydraulic pressure supply source for supplying oil to an oil supply destination T such as a hydraulic device such as a continuously variable transmission mounted on a vehicle.

The electric oil pump 1 is connected to the host ECU 2.
The electric oil pump 1 pumps up the oil stored in the oil pan 3, applies oil pressure, and supplies the oil to the oil supply destination T.

The host ECU 2 is connected to the electric oil pump 1 and the temperature sensor 4.
The host ECU 2 drives the electric oil pump 1 in order to supply the oil to the hydraulic pressure supply T when the engine is stopped by the AND ring stop or the like. For example, when the host ECU 2 stops the engine, a drive command including a target value (hereinafter referred to as “phase current target value”) of the phase current to be supplied to the motor according to the temperature of oil measured by the temperature sensor 4. To the electric oil pump 1.

Next, a schematic configuration of the electric oil pump 1 according to an embodiment of the present invention will be described.
The electric oil pump 1 includes an oil pump 5, a motor 6, a rotation angle detection unit 7, and a drive device 8.

The oil pump 5 is connected to the motor 6 and the oil supply destination T.
The oil pump 5 is a pump driven by the motor 6. The oil pump 5 is driven by the motor 6 to pressure-feed the oil in the oil pan 3 to the oil supply destination T.

  The motor 6 includes a rotor having permanent magnets, and a stator in which coils Lu, Lv, Lw corresponding to the three phases (U, V, W) are sequentially wound in the rotational direction of the rotor. Each of the coils Lu, Lv, Lw of each phase is connected to the drive device 8. For example, the motor 6 is a brushless motor.

  The rotation angle detection unit 7 detects the rotation angle of the motor 6. Then, the rotation angle detection unit 7 outputs an output signal corresponding to the detected rotation angle to the drive device 8.

  The drive device 8 is connected to the host ECU 2 and the motor 6. The drive device 8 controls the drive of the motor 6 based on the drive command output from the host ECU 2. For example, the drive device 8 performs feedback control so that the phase current of the motor 6 becomes the phase current target value included in the drive command input from the host ECU 2. Further, the driving device 8 performs flux-weakening control to increase motor torque when the motor 6 is rotating at high rotation, and executes advance angle control for advancing the energization timing for energizing the motor 6 to the advance angle side.

  Below, schematic structure of the drive device 8 which concerns on one Embodiment of this invention is demonstrated using FIG. FIG. 2 is a view showing a schematic configuration of a drive device 8 according to an embodiment of the present invention.

  As shown in FIG. 2, the drive device 8 includes a power supply unit 9, an inverter 10, a current sensor 11, and a motor control device 12.

  The power supply unit 9 is, for example, a battery mounted on a vehicle. The power supply unit 9 can use a secondary battery such as a nickel hydrogen battery or a lithium ion battery. Also, instead of the secondary battery, an electric double layer capacitor (capacitor) can be used.

  The inverter 10 has a plurality of switching elements SW, and converts the power supply current into a phase current by performing PWM (Pulse Width Modulation) control of on and off of the switching elements. Specifically, the inverter 10 has six switching elements SW1 to SW6. The inverter 10 switches on and off of the switching elements SW1 to SW6 to convert a power supply current into a phase current.

  The switching elements SW1 and SW4 connected in series, the switching elements SW2 and SW5 connected in series, and the switching elements SW3 and SW6 connected in series are of the power supply unit 9 connected via the current sensor 11. It is connected in parallel between the high potential side and the ground potential.

  The connection point between the switching element SW1 and the switching element SW4 is connected to one end of the coil Lu. The connection point between the switching element SW2 and the switching element SW5 is connected to one end of the coil Lv. The connection point between the switching element SW3 and the switching element SW6 is connected to one end of the coil Lw.

  Although the case where the switching element SW is an n-type channel FET (Field Effective Transistor) is described in this embodiment, the present invention is not limited thereto. For example, IGBT (Insulated gate bipolar transistor) and BJT (bipolar junction transistor) It may be Each of the switching elements SW1 to SW6 has a configuration connected in parallel with the free wheeling diodes D1 to D6. The gate terminals of the switching elements SW1 to SW6 are connected to the motor control device 12.

  The current sensor 11 detects a current flowing through the motor 6 (hereinafter referred to as “phase current”) and outputs the current to the motor control device 12. For example, the current sensor 11 includes a shunt resistor 111 and an amplifier AM.

  The amplifier AM amplifies a voltage difference generated between both ends of the shunt resistor 111 when a power supply current flowing from the power supply unit 9 to the inverter 10 flows to the shunt resistor 111. Then, the amplifier AM outputs a signal obtained by amplifying the voltage difference generated at both ends of the shunt resistor 111 to the motor control device 12 as a current detection signal. The current detection signal indicates a phase current. That is, the current sensor 11 calculates the phase current from the potential difference generated at both ends of the shunt resistor 111, and outputs the calculated phase current to the motor control device 12.

  The configuration of the motor control device 12 according to the embodiment of the present invention will be described below.

  The motor control device 12 includes a current detection unit 13, a position detection unit 14, a rotation speed detection unit 15, a storage unit 16, a control unit 17, and a drive control unit 18. The control unit 17 includes an advance value setting unit 19 and an energization control unit 20.

  The current detection unit 13 detects the value of the phase current flowing through the motor 6 (hereinafter referred to as “phase current value”) based on the current detection signal output from the current sensor 11. Then, the current detection unit 13 outputs the detected phase current value to the advance value setting unit 17 and the conduction control unit 18.

  The position detection unit 14 detects the rotation angle (rotational position of the rotor) of the rotor of the motor 6 based on the signal output from the rotation angle detection unit 7, and detects the detection result as the rotation speed detection unit 15 and the energization control unit Output to 18

  The rotation speed detection unit 15 detects the amount of change per unit time of the signal indicating the rotation angle of the rotor output by the position detection unit 14, and calculates the rotation speed of the motor 6 from the detected change amount. Then, the rotation speed detection unit 15 outputs the calculated rotation speed to the lead angle value setting unit 17.

  The storage unit 16 stores, as an advancing angle table, information in which the number of rotations of the motor 6 and the advancing angle value of the energization timing to the motor 6 are associated. FIG. 3 is a diagram for explaining an advance angle table according to an embodiment of the present invention.

  In the lead angle table, the number of rotations of the motor 6 and the lead angle value are associated and stored for each phase current value (for example, the first phase current value, the second phase current value) of the motor 6 . The lead angle value refers to the conduction angle from the current application start phase and the current application end phase for the winding of each phase of the motor 6 from a predetermined position (for example, increase start phase and decrease start phase of inductance) according to inductance change of each phase. Represents the angle at which the angle is advanced.

  Here, one of the features of the present embodiment is that the number of data of the advance angle value stored in the advance angle table differs depending on the range of the number of rotations of the motor 6. Specifically, as shown in FIG. 3, the advance angle table includes a first range in which advance angle data is finely set and a second range in which the advance angle value is set roughly in the number of revolutions of the motor 6. And a range of

The first range is a range in which the rate of change of the current flowing through the motor 6 with respect to the advance angle value is equal to or greater than a predetermined value. For example, the first range is the middle rotation range of the motor 6.
On the other hand, the second range is a range in which the rate of change of the current flowing through the motor 6 with respect to the advance value is less than a predetermined value. For example, the second range is a low rotation area and a high rotation area of the motor 6.

  Therefore, in the example shown in FIG. 3, in the middle rotation area, ten pieces of data are stored in the lead angle table as lead angle value data. On the other hand, in the low rotation region and the high rotation region, three pieces of data are stored in the lead angle table as lead angle value data.

  The lead angle value setting unit 17 determines a lead angle value from the lead angle table based on the phase current value detected by the current detection unit 13 and the rotation speed of the motor 6 detected by the rotation speed detection unit 15. Then, the advance value setting unit 17 outputs the determined advance value to the conduction control unit 18.

  The energization control unit 18 acquires the rotational position of the rotor output from the position detection unit 14 and the advance angle value output from the advance angle value setting unit 17. Then, the energization control unit 18 determines the energization timing for energizing the U-phase winding Lu, the V-phase winding Lv, and the W-phase winding Lw based on the acquired rotational position of the rotor and the advance value. .

  The energization control unit 18 also acquires a phase current target value of the drive command output from the host ECU 2. Then, the energization control unit 18 calculates a deviation between the acquired phase current target value and the phase current value supplied from the current detection unit 13 (hereinafter referred to as “current difference value”). Then, the conduction control unit 18 calculates the duty ratio using generally known PI (Proportional Integral) control or PID (Proportional Integral Derivative) control based on the calculated drive current difference value.

  Then, the energization control unit 18 outputs a timing signal indicating the determined energization timing and the calculated duty ratio to the drive control unit 18.

  The drive control unit 18 generates a drive signal (pulse width modulation signal (PWM signal)) based on the timing signal and duty ratio output from the conduction control unit 18. Then, the drive control unit 18 drives and controls the motor 6 by transmitting the generated drive signal to the gate of each switching element SW in accordance with a plurality of energization patterns set in advance.

  Next, the flow of operation of advance angle control in the motor control device 12 according to an embodiment of the present invention will be described. FIG. 4 is a diagram showing a flow of operation of advance angle control in the motor control device 12 according to an embodiment of the present invention.

  When acquiring the drive command from the host ECU 2 (step S101), the motor control device 12 detects the phase current value of the motor 6 based on the current detection signal output from the current sensor 11 (step S102).

  The motor control device 12 detects the amount of change per unit time of the signal indicating the rotation angle of the rotor output by the position detection unit 14, and calculates the number of rotations of the motor 6 from the detected amount of change (step S103).

  The motor control device 12 determines an advance angle value from the advance angle table based on the detected phase current value and the calculated rotation speed of the motor 6 (step S104). Then, the motor control device 12 executes advance angle control to advance the energization timing to the advance angle side by the determined advance angle value, and drives the motor 6. (Step S105).

  Next, the operation and effect according to the present embodiment will be described. FIG. 5 is a diagram for explaining a conventional advance angle table.

  The conventional motor control device acquires an advance angle value using an advance angle table as shown in FIG. 5 when executing the advance angle control. However, in the conventional advance angle table shown in FIG. 5, the advance angle value is set for each fixed number of rotations, and the data of the advance angle value in each of the low rotation region, middle rotation region and high rotation region The numbers are not differentiated. Therefore, when the conventional motor control device switches the advance angle value using the conventional advance angle table in the middle rotation region where the change in phase current with respect to the advance angle value is large, the advance angle value between the data Because the difference between the two is large, the phase current fluctuates greatly. As a result, it may take time for the rotational speed of the motor to stabilize. Also, if the advance angle table is set finely in order to reduce the variation of the phase current, the capacity of the storage unit (for example, ROM (read only memory)) storing the advance angle table increases. .

  On the other hand, in the advance angle table according to the present embodiment, in the range of the number of rotations of the motor 6, a first range in which advance angle data is finely set, and a second range in which the advance angle value is roughly set. Have. More specifically, the first range is a range in which the rate of change of the current flowing through the motor 6 with respect to the advance angle value is equal to or greater than a predetermined value, and is, for example, the middle rotation range of the motor. On the other hand, for example, the second range is a low rotation region and a high rotation region of the motor. Thereby, in the advance angle table according to the present embodiment, the number of data of the advance angle value can be increased in a region where the change of the phase current with respect to the advance angle value is large, and the difference between the advance angle values between data is reduced. be able to. Therefore, the motor control device 12 can suppress the fluctuation of the phase current when switching the advance angle value in the middle rotation region. As a result, the time required for the motor rotational speed to stabilize can be shortened. Furthermore, in the lead angle table according to the present embodiment, the number of lead angle value data is reduced in the second range in which the rate of change of the current flowing through the motor 6 with respect to the lead angle value is less than a predetermined value. Thereby, the advance angle table according to the present embodiment does not increase the number of data of the advance angle value as a whole as compared with the conventional case, but increases the capacity of the storage unit 16 storing the advance angle table. There is no need to

  As described above, the motor control device 12 according to an embodiment of the present invention stores the advance angle table in which the number of rotations of the motor 6 and the advance angle value of the energization timing to the motor 6 are associated. Equipped with The advance angle table has a first range in which advance angle data is finely set and a second range in which the advance angle is roughly set in the range of the rotational speed of the motor 6. Thereby, the motor control device 12 can suppress the fluctuation of the motor current (phase current value) when performing the lead angle control.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design and the like within the scope of the present invention.

  Although the shunt resistor 111 is used as the current sensor 11 in the above embodiment, the present invention is not limited to this. For example, the current sensor 11 may detect the phase current without contact, and may be, for example, a current transformer or a Rogowski coil.

The respective units included in the motor control device 12 according to the present embodiment may be configured by installing a program for performing various processes related to advance angle control and causing the computer to execute this program. In other words, the motor control device 12 is configured by causing the computer to function as each unit included in the motor control device 12 by causing the computer to execute a program that performs various processes for performing advance angle control in the motor control device 12. It is also good.
The computer has various memories such as a CPU, ROM, RAM, EEPROM (registered trademark), a communication bus, and an interface, and the motor control device is executed by the CPU reading and sequentially executing processing programs stored in the ROM as firmware in advance. Act as 12.

6 motor 12 motor control device 13 current detection unit 14 position detection unit 15 rotation speed detection unit 16 storage unit 17 control unit 18 drive control unit 19 advance angle value setting unit 20 conduction control unit

Claims (3)

A motor control device for controlling driving of the motor,
A rotation number detection unit that detects the rotation number of the motor;
A storage unit for storing an advance angle table in which the number of revolutions of the motor and an advance value of energization timing of the motor are associated;
Based on the number of revolutions of the motor detected by the number-of-revolutions detection unit, the advance angle value is read from the advance angle table, and the motor is driven by energizing the motor according to the read advance angle value. A control unit to control
Equipped with
The advance angle table has a first range in which data of the advance angle value is set finely and a second range in which the advance angle value is set coarsely in the range of the rotational speed of the motor. Motor control device characterized by   2. The motor control device according to claim 1, wherein the first range is a range in which a change rate of the current flowing to the motor with respect to the advance angle value is equal to or more than a predetermined value. The first range is a middle rotation range of the motor, and
The second range is a low rotation region and a high rotation region of the motor,
The motor control device according to claim 1 or 2 characterized by things.

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