| 摘要 |
PURPOSE:To prevent occurrence of over or under voltage in a DC circuit at the time of abrupt acceleration or deceleration by adding output power to a voltage control circuit in the control system for a phase control rectifier thereby performing feedforward control. CONSTITUTION:A speed control circuit 6 receives a difference between the speed of an induction motor 4 and a speed reference and produces a torque reference which is provided to a subtractor 11 in order to obtain a torque current reference. The torque current reference is provided to an inverter control circuit 7 and a multiplier 12, and the torque reference of the induction motor 4 is multiplied by the terminal voltage to obtain the output power of an inverter 3. The output power is then added to the output of a voltage control circuit 8 thus obtaining the current reference of a phase control rectifier 1. Input corrent to the phase control rectifier 1 is proportional to the output power of the inverter 3. Consequently, powering and regenerating state of the induction motor 4 can be subjected to feedforward control based on the current reference derived from the torque current reference. By such arrangement, occurrence of over or under voltage in the DC circuit can be prevented at the time of abrupt acceleration or deceleration. |
