| 摘要 |
An elevator system including an elevator car and a drive machine having a DC drive motor, a dual converter, and a phase controller for providing gate drive signals for the dual converter. A reference signal relates to the desired motor armature current is developed in response to the operation of the elevator system. The reference signal indicates when the current source should be switched from one converter bank to the other converter bank. The switching is accomplished by a method which includes retarding the firing angle of the gate drive signals applied to the operative converter, until current is extinguished, applying the gate drive signals to the other converter bank, and advancing the firing angle towards rectification to initiate current flow in the on-coming converter. The rate at which the firing angle is advanced towards rectification is a function of the control signal. |
