Evaluation of direct position estimation based on α-β axes inductance information for IPMSM sensorless control systems

This paper proposes a direct rotor-position estimation method for IPMSMs (Interior Permanent Magnet Synchronous Motors) in low-speed regions including standstill. In general, the rotor position is estimated indirectly by converging the position estimation error into 0 by the phase-locked-loop (PLL). The indirect rotor position estimation methods require the convergence time of position estimation error. On the other hand, the proposed direct rotor estimation method does not require a phase-locked-loop (PLL), which degrades the response of position estimation. The proposed method has possibilities of improving the position estimation response. This paper demonstrates the performance of sensorless control based on proposed direct position estimation.