PMSM sensorless rotor position detection for all speeds by Direct Flux Control

A Direct Flux Control (DFC) method is implemented in this paper in order to acquire the rotor position of a permanent magnet synchronous machine (PMSM), which can be obtained for all speeds and also at standstill. Flux linkage signals are utilized to calculate the rotor position based on trigonometric approximations. Electrical rotor positions are results of this method, which are validated by both software and hardware executions. The measured flux linkage signals are taken into account to analyze their behaviors, especially in frequency domain, which provide a new approximation function of the flux linkage signals. The estimated flux linkage signal function is analyzed and shows that a magnetization curve (BH curve) is one of the most important factors to reach the actual performances of the PMSM. Thus, the exact nonlinear BH curve is necessary to be considered, which has been achieved in the mutual software simulation with Simplorer and Maxwell. A TriCore PXROS platform is connected to the real PMSM to employ the DFC method as the hardware implementation on a real time system.