Motor control device

A motor control device for driving a motor by operating an inverter having a plurality of switching elements that connect a positive electrode and a negative electrode of a DC power supply and a plurality of terminals of the motor, the motor control device comprising:

• a timer circuit that includes:
• a plurality of compare registers for storing an on and off timing of each switching element for each pair of a positive side switching element and a negative side switching element respectively connected to the plurality of terminals of the motor in the inverter;
• and a counter for clocking, and is configured to output a signal representing the on and off timing of each switching element when a value of each of the compare registers matches a value of the counter;
• a control mode setting unit configured to set a control mode of the motor to be one of a PWM mode for turning on and off each switching element at a predetermined timing at regular time intervals and an angle synchronization mode for turning on and off each switching element according to a rotation angle of the motor, based on a command torque input from an external device;
• a PWM control unit configured to perform, at regular time intervals, a PWM control for calculating the on and off timing to be set to each compare register for driving the motor with the command torque and outputting the on and off timing to the timer circuit when the control mode set by the control mode setting unit is the PWM mode;
• an angle calculation unit configured to calculate, as a rotation angle of the motor, the on and off timing of each switching element for driving the motor with the command torque at every predetermined rotation angle of the motor;
• and
• an angle synchronization control unit configured to execute an angle synchronization control for writing the on and off timing to each compare register to turn on and off each switching element at the rotation angle calculated by the angle calculation unit, wherein:
• the timer circuit includes a plurality of data registers that store a plurality of on and off timings output from the PWM control unit to each of the compare registers;
• the timer circuit is configured to write the on and off timings stored in the plurality of data registers to the compare registers respectively at the regular time intervals;
• the angle synchronization control unit switches an operation mode of the angle synchronization control unit as a first operation mode to the angle synchronization mode to start the angle synchronization control when the motor reaches a predetermined rotation angle position next time after receiving a first switching command in a case where the first operation mode is the PWM mode;
• the angle synchronization control unit switches the first operation mode to the PWM mode to stop the angle synchronization control when receiving a second switching command in a case where the first operation mode is the angle synchronization mode;
• the PWM control unit outputs the first switching command to the angle synchronization control unit to continue the PWM control when the control mode acquired from the control mode setting unit is the angle synchronization mode until the first operation mode of the angle synchronization control unit is switched from the PWM mode to the angle synchronization mode;
• the PWM control unit outputs the second switching command to the angle synchronization control unit to switch the first operation mode of the angle synchronization control unit to the PWM control immediately before starting a next PWM control after the regular time interval has elapsed in a case where the control mode acquired from the control mode setting unit is the PWM mode, and the first operation mode of the angle synchronization control unit is the angle synchronization mode;
• and
• the angle synchronization control unit:
• sets the first operation mode to the angle synchronization mode according to the first switching command output from the PWM control unit;
• writes a predetermined value not matching the value of the counter;
• and then, starts the angle synchronization control.