Full-speed domain sensorless control of IPMSM based on the sparrow search algorithm

In order to achieve sensorless control across the entire speed range of an Interior Permanent Magnet Synchronous Motor (IPMSM), a sensorless control method for low-to-high-speed switching in an IPMSM is proposed. First, a mathematical reference model of the IPMSM is established. Then, the transition region from low to high speed is then determined by measuring the rotor speed. Based on this,the zero to low speed range uses pulse high-frequency injection(HFI) signals, while the sliding mode observer(SMO) method is used in the medium to high speed range. This enables the estimation of motor speed and position of the rotor in the zero to low speed and medium-high-speed domains, respectively. Improving upon traditional weighted switching methods, a variable weighting coefficient method is adopted. An objective function is formulated, and the optimal weighting coefficients are determined using the Sparrow Search Algorithm(SSA). This ensures smooth transition within the switching region, ultimately achieving sensorless control of the IPMSM across the entire speed range. Simulation results demonstrate the proposed sensorless control method's reliability and stability, with smoother low-to-high-speed transitions and more accurate estimation precision.