摘要 |
An elevator control system has a converter for converting an AC power from a normal power source to a DC power having a variable voltage, an inverter for inverting the DC power from the converter to an AC power having a variable voltage and a variable frequency, and an induction motor energized by the inverter to drive an electric motor. When a power failure occurs on the normal power source as sensed by a power failure sensor, the converter is connected to an emergency power source to be fully fired to generate a DC power higher in DC voltage than that due to the normal power source.
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