Modified Nonlinear Active Disturbance Rejection Control for PMSM Speed Regulation With Frequency Domain Analysis

Strong robustness and smooth speed are two crucial goals of the high-performance permanent magnet synchronous motor (PMSM) drive systems. Conventional active disturbance rejection control (ADRC) strategy generally increases the bandwidth of the extended state observer (ESO) to improve the unsatisfactory disturbance rejection ability, which will inevitably amplify the measurement noise. To address this tough issue, a nonlinear extended state observer (NESO) using finite-time technique is constructed in this article to enhance the anti-disturbance property. On this basis, the NESO with small bandwidth is sufficient to guarantee strong robustness without sacrificing noise suppression performance. Utilizing the frequency-sweep method, the advantages of the proposed NESO-based modified ADRC (MADRC) system can be analyzed in terms of frequency domain characteristics, which is more practical than traditional theoretical analysis from a mathematical point of view. Meanwhile, a quasi-resonant controller is combined with MADRC system to attenuate the main harmonic component of torque ripple for smooth speed. Experimental results are carried out to verify the effectiveness of the proposed control scheme and frequency-sweep analysis method.