Effect of Eddy Currents on the Star-Point Voltage Dynamics of Synchronous Machines for Sensorless Operation

Abstract

In the field of sensorless control for Synchronous Motors (SMs), machine magnetic anisotropy based techinques which exploit the star-point voltage to estimate the rotor position have been applied successfully. Although these techniques present a mathematical model to describe the star-point voltage dynamics, the influence of the eddy currents effects is usually neglected. The inclusion of these effects into the mathematical model can be exploited to improve the measurement techniques and therefore to reduce the position estimation error. Thus, the aim of this work is to improve the mathematical model of the star-point voltage dynamics by considering the presence of eddy currents. Therefore, in the first section of this work a new mathematical model is developed. Through experimental results, this new model is validated and compared with a star-point dynamics model proposed in literature.