In general, the integral sliding mode control (ISMC) with an integral sliding surface would lead to tracking errors under unbalanced and harmonic grid voltage conditions. In order to eliminate tracking errors under these conditions, multi-resonant items are added to the conventional integral sliding surface in the proposed strategy, which can be called multi-resonant-based sliding mode control (MRSMC). A comparison of tracking precision on the ISMC and MRSMC is analyzed. In order to regulate the system powers directly, the errors of instantaneous active and reactive powers are selected as the state variables. Finally, the output current harmonics and a majority of the doubly-fed induction generator’s (DFIG) electromagnetic torque pulsations can be removed under unbalanced and harmonic grid voltage conditions. Simulation and experimental results are presented to verify the correctness and effectiveness of the proposed strategy.

This paper summarizes the main results and contributions of the MagNet Challenge 2023, an open-source research initiative for data-driven modeling of power magnetic materials. The MagNet Challenge has (1) advanced the stateof-the-art in power magnetics modeling; (2) set up examples for fostering an open-source and transparent research community; (3) developed useful guidelines and practical rules for conducting data-driven research in power electronics; and (4) provided a fair performance benchmark leading to insights on the most promising future research directions. The competition yielded a collection of publicly disclosed software algorithms and tools designed to capture the distinct loss characteristics of power magnetic materials, which are mostly open-sourced. We have attempted to bridge power electronics domain knowledge with state-of-the-art advancements in artificial intelligence, machine learning, pattern recognition, and signal processing. The MagNet Challenge has greatly improved the accuracy and reduced the size of data-driven power magnetic material models. The models and tools created for various materials were meticulously documented and shared within the broader power electronics community.

In this paper, based on sampled-data modeling technique, a second-order equivalent circuit that can describe the global dynamic characteristics of dual active bridge (DAB) converter is developed. The proposed technique can characterize the dynamics of the ac current through the transformer and the output voltage. Afterwards, by using a sensitive-based tool, named participation factor, it is identified which state variables are critical for system stability and which state variables provide negligible effects. On this basis, the large-signal equivalent circuit is simplified, meanwhile the parasitic resistance is still taken into account by an intuitive "loss branch". This model can be used to comprehensively investigate the relationship of the DAB converter stability versus circuit parameters, controller gain, input/reference voltage, and the load conditions, and these results can be expressed analytically. Furthermore, a linearized control method is proposed to eliminate the nonlinear terms in the equivalent circuit model. It facilitates to reduce the sensitivity of system stability to the load condition and reference voltage and helps to enlarge the stable region. Finally, the proposed model is validated by comparing the results obtained by the model with the simulations and experimental results. The effectiveness of the linearized control method is also demonstrated.

Dual active bridge (DAB) converter is one of the most popular bidirectional isolated dc/dc converters. Comparing with the two-level DAB converter, the multilevel DAB topologies take advantages of providing more control degrees of freedom to enhance the control flexibility. Therefore, these topologies are promising alternatives for wide voltage range applications. This article proposed an optimizing modulation strategy for neutral-point-clamped hybrid three-level dual active bridge (NH3L-DAB) converter to minimize the rms value of inductor current and the conduction losses. First, the basic operating principle of NH3L-DAB is analyzed comprehensively in the article. Afterward, the concept of global optimal condition is employed to derive the optimal modulation, and the corresponding analytical expressions of the control coordinates for rms current minimization are derived. By applying the optimal modulation strategy, NH3L-DAB facilitates to break the performance barriers of the prior-of-art of two-level DAB converter when the voltage transmission ratio has large variation. Finally, a bidirectional prototype with 200–450 V input and 20–28.8 V output is built to demonstrate the superior performance of the proposed optimal modulation strategy, and the detailed explanation of the experimental results is given as well.

Due to the quick development of wide bandgap power devices, the power density of the converters is expected to be much higher. In order to increase the power density and efficiency of the DAB converter, especially the efficiency under light load, a quasi-optimal current root-mean-square (RMS) control strategy to achieve All-ZVS is proposed by taking the inductor RMS current optimization algorithm into account in this paper. First the constraint conditions for realizing ZVS of all switching devices under different operating modes are concluded by analyzing the switching mode and the working principle of the DAB converter under the triple phase shift (TPS) modulation. The ZVS domain for All-ZVS operation in each operating mode is further obtained. Then, the GOC strategy is combined with the ZVS condition to derive the novel modulation for all operating modes. Based on this scheme, the switching conditions of all switches can be improved, and the efficiency of the DAB system under the light load is optimized. With ZVS operation, the switching frequency can be raised. Finally, a GaN HEMT based prototype of DAB converter was built and the switching frequency is 200kHz, the effectiveness of the proposed modulation scheme was verified by the experimental results.

For a Vienna type rectifier, unbalanced grids introduce twice the fundamental frequency ripples in dc‐link voltage and input active/reactive power. To eliminate the input power ripple, the common current reference generation strategy, such as dual‐frame hybrid vector control, can be adopted to maintain constant input power and eliminate ripples in dc‐link voltage under light unbalanced grids. However, this control method does not work when under severe unbalanced grids. The theoretical operation area of the constant power control method under unbalanced grids is analysed in this study, furthermore, a compromised control method, which injects a small amount of input power ripple and makes a compromise between the working area and the output voltage ripples, is proposed. The control method can work when the grids have severe unbalance. The experimental operating area of constant power control is presented. The performance comparison and waveforms of three control strategies under different unbalanced grids are given.