Bipolar-Voltage-Injection-Based Position Estimation Method of Planar Switched Reluctance Motors Using Improved Flux Linkage Model

This article proposes a new position estimation method based on an unsaturated flux linkage model for planar switched reluctance motors (PSRMs). The bipolar-voltage-injection method is used to measure the flux linkage, and it is found that ripples caused by iron loss and aluminum eddy current with different amplitudes appear at the troughs of the flux curve. The effect of the losses on the flux linkage measurement is revealed in this article, and the loss compensation models are built based on the analysis. The improved flux linkage model is proposed with the loss compensation models. Then, the position estimation method is given with the improved flux linkage model. Flux linkage measurement result shows that the model with loss compensation has higher accuracy than the conventional model. Initial and planar-motion position estimation experiments are carried out for the PSRM. The initial position estimation error is from -0.4 to 0.4 mm. The planar-motion position estimation errors are from -1.1 to 1.1 mm in the X-axis and from -1.2 to 1.0 mm in the {Y-axis, and the effectiveness of the proposed flux linkage model is verified.