This paper aims to improve the performance of the permanent magnet synchronous motor (PMSM) speed regulation system by combining a novel disturbance observer (DOB) with the super-twisting sliding mode (STSM) technique. First, a STSM controller is constructed to eliminate the adverse effects of the lumped disturbance in the PMSM speed regulation system. A novel DOB is introduced to estimate and compensate the lumped unknown disturbance, which constitutes a composite controller with a feedforward compensation term and a state-feedback control. As a result, the gain of the composite sliding mode controller can be significantly reduced, which will improve the performance of the closed-loop PMSM speed regulation system. The validity and robustness of the proposed composite control scheme are fully verified by simulation and experimental results.

This article designs a novel finite-time extended state observer (FTESO)-based super-twisting sliding mode (STSM) control scheme to promote the anti-disturbance property and tracking performance of permanent magnet synchronous motor (PMSM). First, a FTESO combined with generalized super-twisting technique is constructed to estimate the unknown lumped disturbance and compensate the estimated value to the STSM speed controller. Compared with the conventional extended state observer (ESO), the proposed FTESO can make the estimation error converge to the origin in finite time, which provides a faster convergence speed and higher estimation accuracy. Moreover, to tackle the problem of performance deterioration caused by inertia mismatch, particularly for PMSM speed control, an inertia identification method is employed to calculate the true value of inertia online to tune the parameters of FTESO and STSM controller automatically. Comprehensive simulation and experimental results demonstrate that the proposed control method can improve the robustness of PMSM system in the presence of load torque and inertia variations.

This paper explicitly proposes a novel second-order sliding mode (SOSM) controller based on disturbance observer (DOB) to optimize the disturbance rejection property of the permanent magnet synchronous motor (PMSM) system. Firstly, to tackle the inevitable chattering problem in conventional first-order sliding mode controllers, a new type of SOSM control technique is designed for the speed loop of PMSM system by retaining the discontinuous switching function in the derivative of the actual controller. The proposed controller can not only provide the strong anti-disturbance performance, but also significantly attenuate the potential chattering problem. Then, a DOB constructed based on the auxiliary system is further adopted to compensate the adverse effect generated by the disturbance to enhance dynamical performance. Finally, comprehensive experimental results are provided to verify the effectiveness of the proposed method.

A new super-twisting-like fractional (STLF) controller is proposed in this article to improve the control performance for surface-mounted permanent magnet synchronous motor (SPMSM) system. Compared with the conventional super-twisting sliding mode (STSM) algorithm, the most distinctive characteristic of the proposed strategy is to replace the discontinuous switching function hidden under the integration with a nonsmooth term, which can significantly optimize the performance of SPMSM system. Meanwhile, the introduction of nonsmooth term can provide stronger anti-disturbance capability than the widely used smooth controller. In addition, the desired control performance can be achieved by adjusting the parameters of the proposed STLF controller according to the specific situations. Comparative experiments among the proposed STLF, conventional STSM and proportional integral controllers are carried out to demonstrate the feasibility and effectiveness of the proposed STLF technique.

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.

For the purpose of realizing permanent magnet synchronous motor (PMSM) systems with strong robustness and smooth speed, the quasi-proportional-resonant (QPR) controller is combined with super-twisting extended state observer (STESO) in this paper. Although traditional active disturbance rejection control scheme generally selects a sufficiently large bandwidth of linear extended state observer (LESO) to enhance the time-varying disturbance rejection capacity, the bandwidth of LESO is limited by system stiffness. To solve this tough issue, the STESO using generalized super-twisting technique is developed to optimize the stability and anti-disturbance capacity of motor drive system. In addition, the QPR controller is combined with the proposed STESO to suppress the motor speed fluctuation. Experimental results show that the proposed STESO-based QPR control algorithm has satisfactory characteristics.