| 摘要 |
PURPOSE:To obtain a natural commutation type AC commutatorless motor enabled to be operated even by the power factor 1 of the motor by a method wherein back electromotive force of the motor is used together with an electric power source voltage for commutation on the load side to enable high power factor operation at the neighborhood of the angle of lead gamma-0 deg. of effective commutation. CONSTITUTION:At a commutation control circuit 20 on the load side, a closed loop is formed in regard to frequency, a commutation command on the load side synchronized with the terminal voltage is formed from outputs of a terminal voltage detector 17 and a position detector 16 of the synchronous motor 15, and at the case when gamma=0 deg., commutation of the electric power source is performed, and at the case when gamma>0 deg., commutation of the electric power source is performed together with commutation of back electromotive force. A current feed back system is constituted in a commutation control circuit 19 on the electric power source side, and a commutation command on the electric power source side is so controlled as to make the current iL of a smoothing reactor 14 to follow a current command sent from a speed control circuit 18. The commutation command on the electric power source side, the commutation command on the load side, and a thyristor to input the electric power source voltage and to be triggered are decided in a gate control circuit 21. |
