| 摘要 |
<p>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 to 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 wired to generate a DC power higher in DC voltage than that due to the normal power source.</p> |
