| 主权项 |
1. A motor control apparatus configured to drive and control a three-phase brushless motor configured to rotationally drive a driving shaft of an apparatus installed on a vehicle, the motor control apparatus comprising:
an instruction current calculation unit configured to calculate an instruction current value to the three-phase brushless motor based on a driving state of the vehicle; a PWM control unit configured to output a PWM duty signal to each phase of the three-phase brushless motor according to the instruction current value; a bridge circuit including a switching circuit configured to be driven and controlled by the PWM duty signal, and configured to drive and control the three-phase brushless motor; a current sensor provided at a direct-current bus connected to the bridge circuit, and configured to detect a direct-current bus current passing through the direct-current bus; a phase current calculation unit configured to estimate current values of respective phases based on the direct-current bus current when the PWM duty signal of a maximum phase corresponding to a longest power supply time is turned on and the duty signals of a minimum phase corresponding to a shortest power supply time and a middle phase are turned off among the PWM duty signals to the respective phases of the three-phase brushless motor, and the direct-current bus current when the PWM duty signal of the maximum phase is turned on and the PWM duty signal of the middle phase is turned on; a current feedback circuit configured to perform a feedback correction on the instruction current value based on the current values of the respective phases estimated by the phase current calculation unit; a pulse shift control circuit configured to perform pulse shift control of correcting a phase of the PWM duty signal of the maximum or the middle phase corresponding to a timing when the PWM duty signal of the maximum or the middle phase is turned on in such a manner that a difference between the timing when the PWM duty signal of the maximum phase is turned on and the timing when the PWM duty signal of the middle phase is turned on can reach or exceed a second predetermined value larger than a first predetermined value when the difference between the timing when the PWM duty signal of the maximum phase is turned on and the timing when the PWM duty signal of the middle phase is turned on falls below the first predetermined value, and correcting a phase of the PWM duty signal of the middle or minimum phase in such a manner that a difference between the timing when the PWM duty signal of the middle phase is turned on and a timing when the PWM duty signal of the minimum phase is turned on can reach or exceed the second predetermined value when the difference between the timing when the PWM duty signal of the middle phase is turned on and the timing when the PWM duty signal of the minimum phase is turned on falls below the first predetermined value; a pulse shift phase switching control unit provided at the pulse shift control circuit, and configured to perform pulse shift phase switching control of switching a control target phase on which the pulse shift control is performed, when the middle phase or the minimum phase is changed into the maximum phase, or the maximum phase or the middle phase is changed into the minimum phase according to a change in the instruction current value; and a phase switching subsequent correction amount calculation unit provided at the pulse shift control circuit, and configured to perform phase switching subsequent correction amount adjustment control of determining a correction amount for the phase by the pulse shift control in such a manner that a correction amount after the switching becomes smaller than a correction amount before the switching of the phase for which the pulse shift control is performed in the pulse shift switching control. |
