Speed sensorless control of electrically excited synchronous motor based on the reduce-order state observer flux observation

Abstract

In the speed control system of electrically excited synchronous motor (EESM), flux observer plays an important role, which can detect rotating angle and the amplitude of flux. Essentially, the state observer is the state reconstruction of motor, it can be get according to the state equation of EESM and modern control theory. Due to the mathematical model of EESM is very complex, the state equation is very complex. The design of the reduced-order observer can simplify the structure of the state observer. By combining the flux state observer with model reference adaptive system (MRAS), based on the difference between the reference model and adjustable model, the speed of motor could be identified. Reduced-order observer works as the adjustable model, the current-model flux observation as the reference model, realizing the speed identification of EESM.