| 摘要 |
PURPOSE:To control to smoothly decelerate an AC motor without disorder of torque by stopping energization at a specific angle of an electric angle when the control of the motor is shifted from power drive motor to a regenerative motor. CONSTITUTION:A polarity discriminator 201 outputs a polarity change signal PCS to a microcomputer 112 and a monitor 202 when the polarity of a speed deviation signal epsilonr varies. The monitor 202 counts a resulting pulse Pt from the generating time of a signal PCS, and when the resultant pulses of N/2 pieces are generated, a timeover signal TOS is outputted to the microcomputer 112. The microcomputer 112 inhibits the sinusoidal output by the signal PCS, and outputs a counting direction inverting signal CPS to a counter 111. When a signal TOS representing that 1/2 period is elapsed is generated, the microcomputer 112 again outputs sinusoidal wave of 2-phase on the basis of the counter value of the counter 111. In this manner, when the AC motor is shifted in control from the power drive motor to the regenerative mode, it is stopped energization at 180 deg. of an electric angle, and can be smoothly controlled in deceleration. |
