Adjustable speed polyphase a-c motor drive utilizing an in-phase current signal for motor control
Abstract
Abstract D R A W I N G THE CURRENT AND VOLTAGE TO EACH PHASE OF AN A-C MOTOR ARE SENSED AND UTILIZED TO PRODUCE A PHASE CONTROL SIGNAL HAVING AN AVERAGE VALUE PORTIONAL TO THE AVERAGE MAGNITUDE OF THE IN-PHASE CURRENT WITHIN THAT PHASE. THE PHASE CONTROL SIGNALS ARE SUMMED TO PRODUCE A COMPOSITE SIGNAL INDICATIVE OF CERTAIN MOTOR OPERATING CHARACTERISTICS, INCLUDING SLIP AND TORQUE, THE COMPOSITE CONTROL SIGNAL BEING SUPPLIED TO THE CONTROL OF AN INVERTER WHICH PRODUCES VARIABLE FREQUENCY ALTERNATING CURRENT ELECTRIC POWER FOR DRIVING THE A-C MOTOR. IN RESPONSE TO VARIATIONS IN THE COMPOSITE CONTROL SIGNAL, THE FUNDAMENTAL FREQUENCY AND THE AVERAGE VOLTAGE OF THE ALTERNATING CURRENT POWER ARE ADJUSTED BY THE CONTROL.
Inventors
- 👤 C Graf
- 👤 E Skogsholm
- 👤 W Volkmann
Bibliographic Details
Claims Analysis
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