Dual three-phase permanent magnet synchronous machine (DTP-PMSM) suffers from the disadvantage of easily occurring large stator current harmonics under inverter nonlinearity, nonsinusoidal back-electromotive force, and external disturbances. To deal with the problem, an improved generalized extended state observer (IGESO) for current harmonic suppression is proposed in this article. First, the relationship between the observation of low-frequency and high-frequency periodic disturbances in conventional disturbance observers is explored. Second, a notch filter is used to optimize the conventional generalized extended state observer (GESO) structure to avoid interference in observing two different frequency disturbances. Then, a novel observer poles design principle is proposed, which can control the suppression frequency range and attenuation of periodic disturbances respectively. Besides, the performance compared with other strategies and the stability analysis of IGESO in the discrete-time domain are presented. The parameter range for system stability is also provided. Finally, the proposed method is evaluated on a laboratory DTP-PMSM platform.

Model predictive current control (MPCC) based on sliding mode disturbance observer (SMDO) effectively addresses the issues arising from parameter mismatches and unmodeled nonlinear elements in Permanent magnet synchronous motor (PMSM). However, conventional sliding mode faces a trade-off between reaching speed and chattering, and their closed-loop transfer functions are often challenging to derive. To overcome these limitations, this paper proposes a model-free predictive current control method based on an adaptive sliding mode disturbance observer (ASMDO-MFPCC). By exploiting a novel decoupled PMSM ultra-local model and a novel sliding mode control law, a discrete-time observer is designed to enhance convergence speed and suppress chattering. The stability of the observer is analyzed, and its parameter ranges are theoretically determined. Moreover, by linearizing the control law near the designed sliding surface, a complex vector linear model is established for the entire system, allowing closed-loop transfer function analysis to confirm that deadbeat performance can be preserved under accurate parameter settings. To further improve the system’s robustness, a simple yet effective inductance identification algorithm is proposed for real-time calibration of the predictive control system. This algorithm operates independently of the observer design. Experimental results validate the effectiveness of the proposed current control scheme.

To avoid the complex process of the weighting factor designing in model predictive torque control (MPTC) of surface permanent-magnet synchronous motor (SPMSM), a novel double vector MPTC without weighting factor is proposed in this article. First, the cost function of the torque and stator flux is converted into the voltage function in the two-phase synchronous stator frame. Meanwhile, the coordinate expression of an optimal reference vector, which can simultaneously satisfy the deadbeat condition of torque and flux, is derived by the proposed geometrical method. Then, to minimize the distance from the synthesizing vector to the reference vector, the zones of the linear modulation and overmodulation are divided into several parts. Accordingly, the principle of the double vector selection and the duty cycle calculation are presented in detail. Meanwhile, to improve the robustness, a detailed robustness analysis is conducted and an effective parameters identification method is proposed. Finally, the experimental verification is carried out on a 1 kW SPMSM drive system. Compared with two existing double vector MPTC methods, the proposed method can reduce the THD of the stator current, torque ripple, and stator flux ripple. Meanwhile, a faster dynamic response can be obtained by the proposed MPTC method.

Controlling three-phase current source rectifiers presents intricate challenges due to the input LC filters and DC bus capacitors. This paper proposes a multiple-loop-based control strategy for current source PWM rectifiers for low-voltage DC distribution systems to address these challenges. Firstly, the independent control of the active and reactive power is achieved based on the adjustment of the d-axis and q-axis currents on the grid side. Subsequently, a compensation scheme of capacitance current using the phasor method is proposed. Next, as an alternative damping method, the capacitor-voltage feedback is used to suppress the LC resonance, and the influence of the feedback gains on the system's stability is discussed. Furthermore, the dynamic performance is further improved by adopting DC-side inductor-current feedback and a damping factor. Ultimately, the feasibility and efficacy of the proposed approach are confirmed through experiments.

Compared to the voltage source inverter, the current source inverter (CSI) can boost voltage and improve filtering performance. However, the DC side of CSI is not a real current source, and the DC input current comprises a DC power supply and an inductor. In the switching process, the DC-link inductor is charged or discharged and is in an uncontrollable state. This paper proposes a novel CSI topology containing five switching tubes and a modulation strategy based on the hysteresis control strategy of the DC-link current. Due to the conduction and switching loss being positive to the DC-link current, the calculation method for the least reference value of the DC-link current is derived to meet power requirements. By constructing a virtual axis, we then present the control strategy of the output voltage in a two-phase rotating reference frame. Finally, we carry out the simulation and experiment are to validate the proposed topology, modulation, and control strategy.

Due to the influence of parasitic internal parameters and junction capacitance, the silicon carbide (SiC) power devices are frequently marred by significant overshoots in current and voltage, as well as high-frequency oscillations during the switching process. These phenomena can severely compromise the reliability of SiC-based power electronic converters during operation. This study delves into the switching transient of the SiC MOSFET with the goal of establishing a quantitative correlation between the gate driving current and the overshoot in both the drain-source voltage and the drain current. In light of these findings, the innovative active gate drive (AGD) circuit, which features an adjustable gate current, is introduced. Throughout the switching process, the AGD circuit employs a dynamic monitoring and feedback mechanism that is responsive to the gate voltage and rate of change in the drain-source voltage and drain current of the SiC MOSFET. This adjustment enables gate driving current to be actively modified, thereby effectively mitigating the occurrence of overshoots and oscillations. To empirically validate the efficacy of the proposed AGD circuit in curbing voltage and current overshoots and oscillations, a double-pulse experimental setup was meticulously constructed and tested.