PI Fuzzy Logic Control for Current-Feedback-Based Flux-Weakening Approach of BLDC Motor Operation at High-Speed Region

In applications requiring high-speed operation, a flux-weakening control strategy (FWCS) applied to brushless direct current (BLDC) motors is essential. This paper explores a current-feedback-based FWCS, where the d-axis current is derived from the q-axis current error through a proportional-integral (PI) controller, chosen for its stability and robustness. Notably, the PI controller parameters are dynamically adjusted using fuzzy logic control (FLC) to enhance performance. The performance of the proposed FWCS with FLC is first validated in conditions of both various speed ranges and load changing. Then, it is compared to a fixed-parameter proportional-integral (PI) controller under conditions where the stator inductance varies up and down by 30%. The simulation results demonstrate that integrating FLC within the FW CS significantly reduces the settling time of the q-axis current error and, consequently, the rotor speed. The proposed FWCS for the BLDC motor can be fully implementable in practice.