JP2000023499A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sense surely the error in the rotational direction of a motor with a simple method, by comparing its sensed torque-current value with its computed torque-command value to monitor the direction of its output torque. SOLUTION: Converting a torque-command value 20 which is sent from a torque-command-value computing portion 18 to a motor control CPU 12 into Id- and Iq-command values 24, 26 in a current-value computing portion 22, a proportional plus integral computation is applied to the Id- and Iq-command values 24, 26 in a comparing and adjusting portion 28, and the computed two- phase Id-and Iq-command values 24, 26 are further converted into three-phase current-command values 30 to be sent to an inverter 14. Then, sensing output currents sent from the inverter 14 to a motor 16 in the course thereof, they are fed back to the motor control CPU 12 and are converted into sensed Id' and Iq values 36, 38 in a feedback conversion portion 34 to be sent thereafter to the comparing and adjusting portion 28. On the other hand, a sensed Iq' value 40 which has been fed back from the output currents is also sent to a torque-direction monitor portion 42 present in a vehicle control CPU 10 to judge the outputting direction of the motor 16. Thereby, a motor output made in its reverse direction can be judged simply.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device, and more particularly to a motor output torque control.

[0002]

2. Description of the Related Art Permanent magnet motors and induction motors are used as traveling motors of electric vehicles, and vector control is generally used for torque control of these motors. In the vector control, the motor primary current is converted into an exciting current component I
d and the torque current component Iq. here,
Id is a component for generating a secondary magnetic flux in the motor, and Id
q is a component that causes the motor to generate output torque. I
While d is a component that does not affect the direction of the output torque, that is, the rotation direction of the motor, Iq is a component that does not affect the direction of the output torque, and the rotation direction of the motor is determined by the sign of Iq. Therefore, Iq corresponding to a positive torque command for moving the car forward has a plus sign,
Conversely, Iq corresponding to a negative torque command for moving the vehicle backward has a minus sign.

[0003] In order to perform torque control quantitatively without being affected by disturbance, feedback control is generally performed.
The Id and Iq command values obtained by calculating the torque command are compared with the Id and Iq detection values obtained by feeding back the output current sent from the inverter to the motor, and the difference is subjected to arithmetic processing such as proportional, integral, and derivative. The output torque of the motor is controlled by adjusting the output of the inverter based on the signal thus obtained.

[0004] The torque control of the motor is performed by a motor control C
Performed by the PU. The motor control CPU computes the output torque command into Id and Iq, compares the feedback torque with the detected Id and Iq detection values, performs a proportional integration process on the difference, and sends a control signal to the inverter. It is composed of a feedback converter that feeds back the output current sent to the motor.

[0005] The output torque command is issued from the vehicle control CPU that detects a driver's accelerator operation or the like, and is sent to the motor control CPU as an output torque command value. Vehicle control C
The PU is a CPU that controls an accelerator, a brake, a shift position, and the like related to a vehicle other than the motor. For example, when the accelerator is depressed, the output torque command value is sent from the vehicle control CPU to the motor control CPU, subjected to arithmetic processing, and converted into a signal for controlling the inverter. An output torque corresponding to the depression of the accelerator is generated in the motor by the supply current converted into three-phase AC by the inverter receiving the control signal.

[0006]

However, the motor control C
Id and Iq of the PU are used to calculate Id from the torque command value.
When obtaining d and Iq, there may be a case where a calculation abnormality occurs in which Iq is incorrectly given a sign opposite to the torque command value. In such a case, there is a possibility that the vehicle moves backward contrary to the command to move forward. Such abnormalities can be dealt with by various methods, but there is a demand for surely dealing with them as simply as possible.

[0007]

According to the present invention, there is provided a vehicle control CPU having a torque command value calculating section for calculating a torque command value of a motor and sending the torque command value to a motor control CPU, and based on the torque command value. A current value calculation unit that calculates an excitation current command value and a torque current command value; a comparison adjustment unit that controls an inverter based on the excitation current command value and the torque current command value; and a current output from the inverter to the motor. And a feedback converter for detecting and feeding back an excitation current detection value and a torque current detection value, wherein the comparison and adjustment unit feeds back the excitation current command value and the torque current command value from the current value calculation unit. Motor control CP that adjusts the output current of the inverter by comparing the detected exciting current value and the detected torque current value sent from the converter.
U, the motor control device comprising: comparing a torque current detection value sent from the feedback conversion unit with the torque command value calculated by the torque command value calculation unit to determine a direction of a motor output torque; The vehicle control CPU is provided with a torque direction monitoring unit for monitoring the torque direction.

In the present invention, the detected torque current value fed back is sent to the torque direction monitoring section of the vehicle control CPU, and is compared with a synchronous torque command value of the vehicle control CPU. It is determined whether the codes are the same. Further, it is determined whether or not the detected torque current value is within an appropriate range with respect to the torque command value.

In the present invention, since the torque direction monitoring unit is provided in another CPU different from the motor control CPU, it is possible to reliably detect the torque direction and to simplify the configuration.

[0010] Preferably, the vehicle control CPU has a map in which upper and lower limits of a torque current value with respect to a torque command value are set. Since such a map only determines the upper limit value and the lower limit value, the map can be simplified and an abnormality in the torque direction can be easily detected. Also, the vehicle control CPU
Is originally present and does not require a special circuit.

If there is an abnormality in the calculation of the torque current in the current value calculation unit and a current value having the opposite sign to the torque command value is erroneously given by calculation, the upper limit value or the lower limit value of the map will be exceeded. An abnormality is detected in the torque direction monitoring unit. If an abnormality is detected, the driving of the motor is stopped.

[0012]

Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a system configuration of an electric vehicle to which the present invention is applied. Vehicle control CPU10
Mainly controls an accelerator, a brake, a shift position, and the like regarding a vehicle other than the motor. It also has a function of calculating an output torque command generated by a driver's accelerator operation or the like into a torque command value and sending the torque command value to the motor control CPU 12. Motor control CPU 12 to which the torque command value is sent
Transmits a control signal to the inverter 14 based on the torque command value, thereby controlling the motor 16 for running the vehicle.
The inverter 14 converts the discharge output of the battery from DC to three-phase AC and supplies it to the motor 16. Here, a three-phase permanent magnet motor is used as the vehicle driving motor.

The vehicle control CPU 10 has a torque command value calculator 18 for calculating an output torque command from an accelerator or the like into a torque command value. In addition, a torque direction monitoring unit 42 which is a characteristic part of the present invention is provided, and will be described later.

The motor control CPU 12 calculates the torque command value 2
A current value calculation unit 22 for calculating 0 into Id and Iq, and an Id ′ detection value 36 and an Iq ′ detection value 38 which are fed back by the Id command value 24 and the Iq command value 26 obtained by the calculation, respectively.
And a comparison adjustment unit 28 that performs proportional-integral control of the difference to convert the two-phase current command value to three-phase, and an inverter 1
4 and a feedback converter 34 for feeding back the output current sent to the motor 16 to convert the three-phase current into a two-phase current.

The torque command value 2 sent from the torque command value calculation unit 18 to the motor control CPU 12 by serial communication
The 0 is converted into an Id command value 24 and an Iq command value 26 by the current value calculation unit 22 and sent to the comparison adjustment unit 28. In addition, the output current from the inverter 14 is fed back to the comparison adjustment unit 28, and the current values Id ′ detection value 36 and Iq ′ detection value 38 converted by the feedback conversion unit 34 are sent. In the comparison adjustment unit 28,
A difference between the Id command value 24 and the Id 'detection value 36 and a difference between the Iq command value 26 and the Iq' detection value 38 are obtained, and a proportional operation (P operation) and an integral operation (I operation) are performed. The two-phase command value calculated by the PI is further converted to a three-phase U phase,
The current command value 30 is converted into a V-phase and W-phase current command value 30 and sent to the inverter 14 as a switching signal. Such U phase,
The inverter 1 is controlled by the current command value 30 including the V phase and the W phase.
4 is switched, and an AC output current is supplied to the motor 16.

The output current from the inverter 14 to the motor 16 is detected on the way and fed back to the motor control CPU 12. The detected current 32 fed back is
In the feedback converter 34, the Id ′ detection value 3
6, is converted to the Iq ′ detection value 38 and sent to the comparison adjustment unit 28.

Here, Iq command value 26, Iq 'detected value 3
8 has a plus or minus sign, and when the current value calculation unit 22 performs a normal calculation,
It has the same sign as the torque command value 20. On the other hand, when the sign of the Iq command value 26 is opposite to the sign of the torque command value 20 due to a calculation error, the Iq ′ detection value 38 also has the opposite sign to the torque command value 20. If the sign of the torque command value 20 does not match the sign of the Iq command value 26,
, And the output torque direction is erroneous.

In order to monitor the error in the output torque direction, the detected Iq 'value 40 fed back from the output current is further sent to a torque direction monitoring unit 42 in the vehicle control CPU 10. The torque direction monitoring unit 42 compares the torque command value 44 sent from the torque command value calculation unit 18 with the sign of the synchronous Iq ′ detection value 40 to determine whether there is a calculation abnormality, that is, whether the output torque direction of the motor is Determine if it is normal.

The torque direction monitoring unit 42 has a built-in T-Iq 'upper / lower limit map which gives an upper limit value and a lower limit value of the torque command value of the permanent magnet motor versus the detected value of Iq'. By referring to this map, the correctness of the torque direction is determined.

FIG. 2 shows a T-Iq ′ upper / lower limit value map.
In this map, the upper limit value and the lower limit value are set based on the torque command value vs. Iq command value map used in the current value calculation unit 22. Since only the upper limit value and the lower limit value are determined, it is simpler than the torque command value vs. Iq command value map used in the current value calculator 22. For example, in the normal state,
If the torque command value is 50 and the Iq ′ detection value is 75, the motor is located in the first quadrant of the map, and the motor normally rotates in the forward direction. On the other hand, when the torque command value is 50 and the Iq ′ detection value is -7
If the value is 5, the signs do not match, and the motor rotates in the reverse direction against the forward command. At this time, since it is located in the fourth quadrant of the map and Iq is lower than the lower limit value of −13, it is detected that the calculation is abnormal. When the torque command value is −50 and the Iq ′ detection value is −75, the vehicle is located in the third quadrant of the map, and the torque command value is also Iq ′.
Since the detected value also has the same negative sign, the motor rotates normally in the reverse direction. On the other hand, when the torque command value is -50
When the Iq ′ detection value is 75, the abnormality calculation is detected when the Iq ′ detection value is located in the second quadrant of the map and exceeds the upper limit value of 13. In this case, the motor rotates in the forward direction opposite to the reverse command. By providing the map in the vehicle control CPU, it is possible to easily detect an abnormality in the output torque direction.

Further, this map shows that the torque command value and the I
Even if the q ′ detection value is in the same sign direction, if a large Iq detection value exceeding the upper limit and the lower limit with respect to the torque command is sent, it is determined that the output torque is abnormal due to excess output. . For example, this is the case where the torque command value is 30 and the Iq ′ detection value is 200. According to this map, not only the output torque direction but also the output torque excess command
Can be monitored. If any abnormality is detected, the operation of the motor is stopped for safety. Desirably, the operation of the motor is stopped when the detection is continuously performed for 500 msec.

[0023]

Since the present invention is configured as described above, the vehicle control CPU which is a CPU other than the motor control CPU monitors the torque current detection value. Output in the opposite direction and abnormal output of the motor can be easily determined.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of a motor control device of the present invention.

FIG. 2 shows T- used for determining an error in the rotation direction of a motor.
It is an Iq 'upper / lower limit map.

[Explanation of symbols]

10 vehicle control CPU, 12 motor control CPU, 14
Inverter, 16 motor, 18 torque command value calculator, 20 torque command value, 22 current value calculator, 24
Id command value, 26 Iq command value, 28 comparison adjustment unit, 3
0 current command value, 32 detection current, 34 feedback conversion unit, 36 Id 'detection value, 38, 40 Iq' detection value, 42 torque direction monitoring unit, 44 torque command value.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (2)

[Claims] 1. A vehicle control CPU having a torque command value calculator for calculating a torque command value of a motor and sending the torque command value to a motor control CPU; an excitation current command value and a torque current command based on the torque command value A current value calculating unit for calculating a current value, a comparing and adjusting unit for controlling an inverter based on the exciting current command value and the torque current command value, and detecting and feeding back a current output from the inverter to the motor. A feedback converter for converting a current detection value and a torque current detection value, wherein the comparing and adjusting unit converts the excitation current command value and the torque current command value from the current value calculation unit to the excitation current transmitted from the feedback conversion unit. Motor control C that adjusts the output current of the inverter by comparing the detection value and the torque current detection value
A motor control device comprising: a PU; and comparing a torque current detection value sent from the feedback conversion unit with the torque command value calculated by the torque command value calculation unit to determine a direction of an output torque of the motor. A motor control device, wherein a torque direction monitoring unit for monitoring the torque is provided in the vehicle control CPU. 2. The motor control device according to claim 1, wherein the vehicle control CPU has a map in which upper and lower limits of a torque current detection value with respect to a torque command value are set, and the torque direction is set based on the map. A motor control device, wherein the monitoring unit monitors the output torque of the motor.