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.

The extended state observer (ESO)-based deadbeat active disturbance rejection control (DB-ADRC) is commonly employed for high-performance torque or current control, however, it performs poorly when rejecting current harmonics caused by periodic disturbances, such as inverter nonlinearities and flux harmonics. The internal model-based method, such as resonant control, can be combined with ESO to mitigate current ripples when the harmonic frequencies are known, which however is not always the case in real applications. In this article, an online-trained radial basis function neural network (RBFNN) compensator with fast training process is integrated into the DB-ADRC system to simultaneously suppress the aperiodic and harmonic disturbances without knowing harmonic frequencies. By using the proposed scheme, current harmonics under various speed and load conditions can be effectively suppressed without affecting dynamic performance. Various experiments are conducted on the test bench based on the dSPACE MicroLabBox and permanentmagnet synchronous motor to validate the effectiveness of the proposed method.

This article presents a contra-rotating (CR) brushless integrated flux-modulation (BIFM) machine with an open-slot structure for wind power generation, termed CR-BIFM machine. The presented machine employs two CR rotors coupled with two sets of wind turbine blades, thus being able to capture more wind energy than conventional single-rotor wind turbines. Owing to the dual-flux-modulation effect and flux-bridge effect, the presented machine exhibits high torque/power density, making it suitable for direct-drive wind power generation without issues related to mechanical gearboxes. As two sets of windings share the same stator slots in the presented machine, the decoupling design of windings is systematically investigated from the perspective of airgap-modulated magnetic field, considering the influence of both stator and rotors. The advantages of the presented machine are comprehensively evaluated compared with the baseline machine, showing that the presented machine exhibits higher torque/power density, higher efficiency, higher power factor, higher permanent magnet utilization, and better vibration performance. Finally, a prototype is fabricated and tested to validate the analysis.

As the demand for high precision in permanent magnet synchronous motors (PMSM) increases, achieving superior disturbance rejection in PMSM speed regulation becomes essential. In this context, active disturbance rejection control (ADRC) has emerged as a widely employed method. To enhance disturbance rejection, researchers have explored higher-order extended state observers (ESO) and cascaded ESO (CESO). However, the unclear relationship between these approaches leads to redundant efforts, and the fixed ESO structure used in constructing CESO often limits its potential improvement. Additionally, the impact of individual observer bandwidth within CESO on the overall system is poorly understood. To address these gaps, this paper analyzes various ESO structures for constructing CESO and identifies two promising CESO configurations with improved disturbance rejection. Subsequently, a comparative analysis of different observer bandwidths is conducted to optimize performance. Furthermore, this paper establishes the equivalence between CESO and higher-order ESO. The results are validated through theoretical analysis and experimental tests using dSPACE DS1202 MicroLabBox.

Fault-tolerant control (FTC) strategy can be realized without modifying the peripheral hardware circuit when the open-circuit fault (OCF) occurs in the multiphase motor. However, FTC relies on accurately identifying the fault location and switching to a new reconfiguration fault-tolerant algorithm. This can significantly increase the complexity of the system. To overcome the challenge, this article investigates a passive fault-tolerant scheme of a 2 × 3-phase surface-mounted permanent-magnet synchronous motor (SPMSM) driven by a mono-inverter when single-phase OCF occurs. The state equations based on field-oriented control of 2 × 3-phase SPMSM under healthy and single-phase OCF are discussed. The special motor drive mode and the constraint of i_d = 0 make the phase currents of each module passively optimized under the two neutral point configurations (i.e., isolated or connected), thus meeting the demand of restraining torque ripple. In the proposed PFTS, when the OCF occurs, the system does not require to attempt to diagnose or correct faults. Hence, a seamless transition from normal to faulty operation is guaranteed. Moreover, it enhances system reliability and stability. Furthermore, taking an existing 2 × 3-phase SPMSM as an example, the experiments are carried out for validation.

Fault-tolerant ability of dual three-phase permanent magnet synchronous motors (PMSMs) is crucial for safety-critical applications. When a single open-phase fault occurs, the current references in conventional methods must be adjusted for avoiding the generation of torque ripple. Meanwhile, their design should balance the tradeoff between the torque operation range (TOR) and the copper loss. However, these postfault current references still need to be retailored under different open-phase fault locations; otherwise, more severe system damage may occur. Aiming to improve the robustness of the control algorithm, this article has proposed an online postfault strategy that can achieve minimum copper loss while maximizing the TOR for dual three-phase PMSMs with sinusoidal back-EMF. Unlike existing literature, the current reference in the harmonic subspace can be uniformly determined by the intermediate variable of phase shift and amplitude ratio, independent of fault scenarios. Additionally, the required fault identification is reduced from locating a specific phase to identifying one set of three-phase windings. The postfault performance of minimum copper loss can be achieved during the full TOR. Furthermore, the implementation of proposed algorithm does not require any optimization iterative process or look-up tables. Comprehensive experimental results have verified the effectiveness of the proposed method.