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 inverter d rive system (38). The inverter (38) receives command signals for the fundamental frequency d and q axis currents (40, 41) and hig her frequency voltage command signals (42) from a positi on and velocity observer (43). The position and velocity observer (43) uses in formation from the signals (44, 45) to provide estimates for the rotor position and speed provided as output signals (47, 48). The direct fie ld oriented controller (50) includes a flux regulator (5 8), a torque calculator (60) and a rotor flux observer (61) and provide the inverter (38) with the fundamental frequency current command signals (40 41). Conventional induction motors can be provided with sufficient spatial v ariations in the stator winding impedance as a function of rotor position by varying the depth and/or width of the slots over the rotor condu ctive bars or by varying the cross-section of the bars, or by filling or partially filling some of the slots.