Sensorless rotor position estimation at standstill of high speed PMSM drive with LC inverter output filter

This paper presents a new innovative method for sensorless rotor position estimation at standstill for high speed PMSM. To avoid critical thermal losses in the high speed PMSM a controlled LC filter is connected between the machine and the inverter. This additional filter leads to failure of many known methods for sensorless rotor position detection at standstill. The presented method is suitable for accurate and reliable detection of the rotor position at standstill. The function principle is based on voltage pulses applied on the LC filter and the high speed PMSM. Based on measured stator currents and voltages a special structure to model the system behavior and to calculate the actual rotor position is used. This allows a parameter insensitive operation. All theoretical proposals are proved by practical experiments.