| 摘要 |
The invention relates to a synchronizing apparatus for motor drives with at least one asynchronous or synchronous motor 1 which is alternatively connectible to a frequency converter 3 or to an electric a.c. supply network 2. The apparatus comprises a device A for comparing the zero passage of the network voltage with the firing pulse position of a suitably chosen firing pulse in the inverter section 5 of the frequency converter, and switching from the converter to the network, or vice versa, for the motor takes place when the voltage passes through zero and the network voltage and the fundamental frequency of the converter output voltage are in phase. Due allowance is made for the operating times of the switches 8, 9 controlled by the device A. <IMAGE> |
