Sensorless Control of Permanent Magnet Synchronous Linear Motor Based on Improved Second-Order Generalized Integrators

Band-pass filter (BPF) and low-pass filter (LPF) are generally used to extract the position error signal of permanent magnet synchronous linear motor (PMSLM) in the traditional high-frequency (HF) pulsating voltage injection method. However, filters will generate system delay and affect the dynamic performance of the system. Therefore, this paper proposes to combine the generalized second-order integrator (SOGI) and notch filter (NF) to form an improved generalized second-order integrator (SOGI-NF). This structure effectively reduces the time delay caused by signal processing and shortens the operation time by replacing the BPF. Meanwhile, compared with the traditional SOGI, it has stronger harmonic attenuation ability, wider bandwidth and better dynamic performance. Finally, the feasibility and superiority of the position error signal extraction strategy based on the improved second-order generalized integrator are verified by simulation.