Torque-Pulse-Based Initial Rotor Polarity Detection for IPMSM with Low Saturation Effect

Referring to the sensorless control of interior permanent magnet synchronous motor (IPMSM), initial rotor polarity is normally estimated based on saturation effect. However, for certain special IPMSMs, effect weak even at rated point, making saturation-based detection methods invalid. Therefore, this paper proposes a novel method torque-pulse injection. Two current pulses are imposed positive and negative directions q-axis by high-frequency injection (HFI) method, respectively; signs speed peaks indicate polarity. To derive from tiny signal, new estimation presented. improve dynamic performance estimation, filter adopted in HFI method. choose proper width amplitude pulse under different load inertia conditions, an automatic program designed. The proposed has advantages high accuracy, short identification time, movement, operation, it applicable various conditions. effectiveness validated experiments IPMSM with low