Self generative variable speed induction motor drive

摘要

An inverter controls an induction motor in response to signals from a power factor control circuit. The power factor control circuit receives signals related to motor terminal voltages and multiplexes them to a comparator. The inverter and multiplexor are sequenced each time the comparator input reaches a reference level. The frequency of the inverter is thus self generated. The power factor of the system can be controlled to implement a variety of control strategies.