| 摘要 |
A polyphase induction motor propels an elevator car. The motor is powered by a multiphase inverter which receives power from a battery. The inverter is controlled in such a way as to control the frequency and amplitude of the power supplied to the motor in order to control the motor's speed, acceleration, and slip. That inverter control is accomplished by sensing the motor's speed and in response providing predetermined slip and torque signals. The slip can be controlled over a range which can provide negative slip, by which power is regenerated into the battery, which is thereby charged, and positive slip for motoring torque. A charger also charges the battery. The motor and its controls are thereby ostensibly isolated from the power system that supplies power to the charger, the battery handling the peak power requirements. Thus, little noise is injected into the power system. This motor control system is thus efficient to operate, economical to build and very quiet.
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