首页>
外国专利>
THREE-PHASE POWER FACTOR CONTROLLER WITH INDUCED EMF SENSING
THREE-PHASE POWER FACTOR CONTROLLER WITH INDUCED EMF SENSING
展开▼
机译:感应电动势感应的三相功率因数控制器
展开▼
页面导航
摘要
著录项
相似文献
摘要
A power factor controller for an A.C. induction motor (10) is provided which is of the type comprising thryistor switches (110), (111) and (112) connected in series with the motor, phase detectors (122), (124) and (126) for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thryistor is "off" and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance "soft" starting of the motor.
展开▼