METHOD AND APPARATUS FOR TRANSDUCERLESS FLUX, POSITION AND VELOCITY ESTIMATION IN DRIVES FOR AC MACHINES

摘要

Power is provided to the stator windings of an AC motor (31) from inverterdrivesystem (38). The inverter (38) receives command signals for the fundamentalfrequency dand q axis currents (40, 41) and higher frequency voltage command signals (42)from aposition and velocity observer (43). The position and velocity observer (43)uses informationfrom the signals (44, 45) to provide estimates for the rotor position andspeed provided asoutput signals (47, 48). The direct field oriented controller (50) includes aflux regulator(58), a torque calculator (60) and a rotor flux observer (61) and provide theinverter (38) withthe fundamental frequency current command signals (40, 41). Conventionalinduction motorscan be provided with sufficient spatial variations in the stator windingimpedance as afunction of rotor position by varying the depth and/or width of the slots overthe rotorconductive bars or by varying the cross-section of the bars, or by filling orpartially fillingsome of the slots.