LQR optimal control method for high switching frequency single‑phase Lorentz motor drive system

The single-phase Lorentz motor, serving as the micro-actuator in macro-micro motion stages of high-precision manufacturing systems, demands a drive system with high bandwidth and minimal current ripple to achieve nano scale motion control. This paper presents a high-switching-frequency drive system tailored for such motors. Starting from a core PI-controlled current loop, the system is enhanced through optimized current sampling and duty cycle update timing, along with the integration of LC output filtering. To address the instability caused by LC resonance, an active suppression strategy based on the Linear Quadratic Regulator (LQR) is proposed. The resonance suppression is reformulated as a state-tracking problem, where frequency-adaptive optimal damping is achieved via the tuning of cost function weight matrices. A Luenberger full-state observer is also designed to estimate the system’s state variables, enabling the implementation of the LQR controller. Simulation results in MATLAB confirm the proposed system’s excellent steady-state and dynamic performance, meeting the stringent demands of high-precision motion control.