Slip recovery induction motor controller - uses diode rectification of rotor current and two independent series inverter bridges to control phase shift of returned power (BR 13.10.81)

摘要

The induction motor slip recovery system uses diode bridge rectification (RCT) of the rotor (RT) current and two three phase bridge inverters operating in series, each supplying one of two primary windings (SC1,SC2) of a three-winding transformer (TNF) having its secondary (PM) connected to the AC mains (L1,L2,L3). The two bridge inverters (INV1,INV2) are made up of thyristors controlled by two fitting circuits (GC) which allow the firing angles of the inverters to be independently varied . By the control of the inverter firing angles the phase shift of the recovered slip power is held within a narrow range reducing the kVA rating required of the transformer (TNF) and making power factor correction capacitors more effective.