FOUR ROTOR POSITION AND SPEED SIMPLIFIED ESTIMATORS FOR VECTOR CONTROL OF HIGH-SPEED SPMSM, WITH TEST COMPARISONS

Abstract

The surface permanent magnet synchronous machines have a very simple structure due to the fact that Ld=Lq and thus they are favored for high-speed applications. The simplicity of these motors raises problems when sensorless control is desired for the reason that position and speed estimators do not behave, at low speeds, as well as they do in induction and interior permanent magnet synchronous machines. In high-speed applications the online computing cycle is small and therefore simplified position/ speed estimators are needed. Four rotor position and speed simplified estimators were implemented and compared to be used in encoderless systems. Several experimental drive tests are demonstrated, with experimental results showing the effectiveness of all implemented position and speed estimators, in high-speed range