A high-stability control method for high-frequency response of current loop for PMSLM considering voltage saturation

The bandwidth is a crucial factor influencing the dynamic response and disturbance rejection of permanent magnet synchronous linear motors. The motor's bandwidth is ultimately limited by its current loop. Excessive current loop bandwidth may result in system instability and voltage saturation. Consequently, the present loop bandwidth is limited by two primary issues, which complicate parameter tweaking by empirical methods in actual applications. This work presents a design methodology for current loop control parameters with zero-pole cancellation. The cancellation of zeros and poles minimally affects system performance, hence reducing the system to a first-order model. The relationship among current loop bandwidth, system stability, and maximum control voltage is derived, upon which the control parameters are formulated. The theory's validity is confirmed through studies on the current loop and the position loop.