Low Speed Position Estimation Scheme for Model Predictive Control with Finite Control Set

This paper presents the low speed position estimation scheme for an IPM machine controlled by model predictive control with finite control set. The career signal injection is not viable as there is no PWM to superimpose it with PWM for this type of control. The pulse vector injection technique requires current derivative sensors which makes the overall scheme less attractive. This paper utilizes the inherent high frequency vector injection of the model predictive control to extract the position information. It is shown that the high frequency current response is amplitude modulated with respect to the position. A demodulation technique based on the reactive power estimation is proposed. The simulation results at various initial positions confirm the validity of the proposed position estimation scheme.