| 摘要 |
A relatively simple inverter-motor system, comprising a minimum number of circuit components, is provided by employing a voltage-controlled thyristor inverter which in turn drives a synchronous motor having a leading power factor. With the motor current leading the motor voltage, the thyristor switching devices will be motor-commutated, thereby precluding the need for any auxiliary commutating elements or circuits to effect forced commutation. Since, with a leading power factor, the current through a conducting thyristor falls to zero before the thyristor has to be switched off, ample turn-off time is provided. Furthermore, as compared to a conventional forced commutated voltage source inverter, the customary reactive diodes, usually shunting the switching devices in an inverter to permit the flow of reactive motor current, are not necessary. Moreover, by powering the inverter with a voltage source, rather than with a current source, the commutation process is greatly facilitated, the need for damper windings on the motor is eliminated, and the physical size of the d-c link inductor normally required by a current source inverter is greatly reduced. |
