Improvement of rotor position angle estimation in SRD using fuzzy logic based motor model

In this paper, a novel method of sensorless rotor position angle estimation based on the knowledge of motor model and the relation of /spl Psi/-I-/spl theta/ is developed on using fuzzy logic based motor model. Due to electromagnetic interference and measurement error, there are more errors in result. In order to improve the precision of the method, a predictive module is added in system. Through comparing predicted value with estimated value, more accurate value is gotten in test. The result shows that, with improved estimation system, rotor position angle can be accurately estimated in different regions, including startup, low-speed and mid-speed region.