Motor Control System

摘要

Provided is a motor control system that can suppress production costs and suppress the occurrence of unexpected excessive torque, and continues system operation as much as possible even when the diagnosis results of a monitoring device are abnormal. A computation device (3) computes a voltage command value indicating the voltage to impose on a motor (2), and, on the basis of the voltage command value, generates a control signal (Spwm) that controls a drive device (5).;When the diagnosis results (Rd) of the monitoring device (6) are normal, the computation device (3) computes the voltage command value in a manner so that the absolute value of the detection value of current flowing to the motor (2) is no greater than a second threshold, and when the diagnosis results (Rd) of the monitoring device (6) are abnormal, the computation device (3) computes the voltage command value in a manner so that the absolute value of the detection value of current flowing to the motor (2) is no greater than a third threshold that is smaller than the second threshold.

主权项

1. A motor control system comprising:
a motor; a drive device that applies a voltage to the motor; a computation device that computes a voltage command value indicating the voltage applied to the motor and generates a control signal for controlling the drive device based on the voltage command value; a switch that is connected in series between the computation device and the drive device and turns on and off supplying of the control signal from the computation device to the drive device; an overcurrent detection circuit that has a function of turning off the switches when an absolute value of a detection value of a current flowing in the motor exceeds a first threshold value; and a monitoring device that makes a diagnosis for the computation device, wherein the computation device computes the voltage command value so as to cause the absolute value of the detection value of the current flowing in the motor to be equal to or smaller than a second threshold value when a diagnostic result obtained by the monitoring device indicates normality, and computes the voltage command value so as to cause the absolute value of the detection value of the current flowing in the motor to be equal to or smaller than a third threshold value which is smaller than the second threshold value when the diagnostic result obtained by the monitoring device indicates abnormality.