Once the operating frequency of magnetic coupling resonant wireless power transfer (MCR-WPT) reaches the MHz level—for instance, 6.78 MHz (the wireless charging frequency specified by AirFuel)—capacitive parasitic parameters in the magnetically coupled coils will affect the transmission performance of the WPT system and thus cannot be ignored [5]-[6]. Clarifying the formation mechanism and mathematical model of parasitic capacitances in magnetically coupled coils is crucial for mitigating their impacts. Currently, the shortest path method, function method, and improved shortest path method are utilized in [7] to calculate the inter-turn structural capacitances of transformers under high-frequency (HF) conditions. [8] introduces a calculation method for the parasitic capacitance of HF solenoid inductors, which are formed by uniformly winding single-layer coils with a circular cross-section on a cylindrical non-conductive magnetic core. In [9], an analytical method based on conformal transformation is proposed to solve the inter-turn structural capacitances and turn-to-core capacitances of coils with different geometric structures. In [10], the total parasitic capacitance is calculated based on the approximate solution of inter-turn structural capacitances. Existing studies have analyzed the impacts and calculation methods of inter-turn structural capacitances between adjacent turns in transformers and inductors, but they have neglected the influence of inter-turn structural capacitances between non-adjacent turns on the equivalent parasitic capacitance. To optimize the transmission performance of magnetically coupled coils, [11] utilizes the parasitic capacitance of the coils as part of the compensation capacitance. However, this method is only applicable to the parallel/parallel (P/P) compensation topology and not to other topologies such as series/series (S/S), series/parallel (S/P), and series/series-parallel (S/SP) [12]-[15]. [16]-[17] suggest paralleling multiple multi-layer PCB coils to generate large inter-turn structural capacitance for replacing compensation capacitors, thereby improving the reliability of magnetically coupled coil design. Nevertheless, the compensation method that leverages parallel resonance between inter-turn structural capacitance and the equivalent inductance of the coil is only suitable for current-source-driven P/P compensation topologies, not for voltage-source-driven compensation networks such as the S/S topology. Among these studies, [16] addresses this issue by adopting a traditional centralized series compensation capacitor on the transmitter side, but the equivalent parasitic capacitance of the transmitter side still impairs the transmission capability of the magnetically coupled coil.

Aiming at the reliability challenge of metal foreign object detection (FOD) in inductive coupled power transfer (ICPT) systems, a fault classification strategy based on incremental transfer dual-dictionary learning is first proposed. The method first constructs a safety dictionary and a base foreign object dictionary, and introduces a reconstruction error ratio as a decision criterion to achieve fault diagnosis of metal foreign objects. Subsequently, to further enhance generalization capability, incremental transfer learning is integrated to improve the dictionary model. This involves dynamically updating the foreign object dictionary using small samples of unknown metals, with atom addition and fine-tuning to quickly adapt to new foreign object features. Finally, the trained model is evaluated. Experimental results demonstrate that the proposed method achieves a recall rate of over 95% for unfamiliar metal foreign objects after transfer, verifying the effectiveness of the detection approach. This method retains the advantages of unsupervised learning while requiring no detection coils, significantly enhancing its adaptability to complex application scenarios.

Three-port converters are increasingly preferred for standalone PV-battery systems due to their versatility and multifunctional operation, which allow the system to effectively mitigate the effects of intermittency in renewable power generation. However, their reliability is often lower than that of two-port converters, as they involve more components, experience higher thermal stress, require complex control algorithms, and operate in multiple modes. This paper investigates and evaluates the reliability of a three-port power converter under different operating modes using the MIL-HDBK-217F standard. Component-level failure rates were analyzed, and design improvements were proposed to reduce stress and enhance performance. Based on the reliability analysis, a novel reliability-oriented control strategy is proposed to enhance the resilience of the standalone system. By implementing a state-of-charge (SoC) based management algorithm, the converter avoids high-stress operating modes, such as the SISO PV-load mode, thereby extending the expected operational lifetime. The effectiveness of these improvements was verified through LTspice simulations and Scilab calculations, providing a robust validation method given that physical lifecycle testing requires extended operational durations. Results indicate a significant reduction in failure rates, improved system efficiency, and extended operational lifetime.

To simplify the dual-inverter architecture for driving open-end winding induction motors (OEWIMs), this study proposes a dual-port 120° phase-shifted drive scheme based on an L-type dual-output three-level converter (L-DO-TLC). The proposed L-DO-TLC topology is constructed by cascading a T-type three-level inverter with a nine-switch converter in an L-shaped configuration. By reusing devices, it generates two independent three-level outputs, reducing the number of power switches from 24 to 15. Based on this topology, a hybrid-vector (HV) finite control set model predictive control (FCS-MPC) strategy is introduced. The prediction model of the OEWIM is formulated using forward Euler discretization. A voltage vector selection mechanism is then developed based on the zero-sequence current (ZSC) suppression principle, significantly reducing the computational complexity of the predictive control algorithm. To further improve control performance, an HV-MPC decision-making strategy is proposed that jointly optimizes current tracking and vector application. This method effectively mitigates the large torque ripple observed in single-vector (SV)-MPC and the high switching frequency encountered in dual-vector (DV)-MPC. Simulation and hardware-in-the-loop experimental results validate the effectiveness and advantages of the proposed strategy.

This paper presents a switched-capacitor cascaded boost converter designed to overcome the limitations of the traditional topology. The proposed converter integrates a switched-capacitor unit, which enables the superposition of inductor energy onto the output side during the switch-off period, thereby achieving double the voltage gain of a conventional cascaded boost converter (CCBC), as defined by M = 2/(1-D)2. This structure also results in significantly reduced voltage stress on the semiconductor devices. Furthermore, a collaborative filtering mechanism between the primary stage (C2/C3) and the secondary stage (C0) reduces dependency on individual capacitor values while simultaneously enhancing output ripple suppression. Additional advantages include inherent input-output common ground for effective electromagnetic interference (EMI) suppression and a simplified gate driver design due to the synchronized operation of the two switches. The operational principle and steady-state performance are analyzed thoroughly. A mathematical model is derived using the state-space averaging technique and validated by simulation. Experimental results from a 250W hardware prototype (32V input to 400V output) confirm the feasibility of the proposed topology.

The adoption of lithium-ion batteries (LIBs) is rising in electric vehicles (EVs), data centers, and energy storage systems, due to their prolonged cycle life and enhanced safety performance. The battery packs incorporate a battery management system (BMS). BMS is vulnerable to cybersecurity risks because it depends on communication. We need to secure the reference values of battery voltage, current, and state of charge (SoC). If a hacker changes these values, the battery could be overcharged or undercharged. In this context, this paper discusses various communication protocols used in BMS, along with cell-balancing techniques, including active and passive ones. Furthermore, it enlightens the different SoC estimation techniques, such as artificial neural networks (ANN), model-based, data-driven, and statistical-based. These SoC methods are employed on an online dataset of a LIB. It indicates that the ANN has a minimum root mean square error (RMSE) of 0.1%. Moreover, blockchain is utilized to store the BMS data on a private blockchain network for anomaly detection. A hardware prototype is implemented to validate the anomaly data logging. The fabric network shows a maximum throughput rate of 312 for 500 transactions.

To enhance the output voltage quality and system efficiency of a three-phase four-wire (3P4W) three-level inverter under unbalanced load conditions, this paper proposes an optimization strategy for continuous control set model predictive control (CCS-MPC) based on hybrid modulation. First, an active damping method employing a notch filter is integrated into the CCS-MPC to suppress resonance caused by load-filter interactions, improving the output voltage quality. Phase correction is also applied to the output voltage reference generated via two-step prediction. Second, based on neutral-point (NP) voltage balancing control, a fuzzy logic algorithm (FLA)-based hybrid pulse width modulation (HPWM) method is proposed to further increase system efficiency. The FLA evaluates NP voltage fluctuation amplitude and balancing capability to adaptively determine whether to disassemble the O switching state, enabling optimal combination of dual-carrier sinusoidal pulse width modulation (SPWM) and double modulation wave carrier-based pulse width modulation (DMW-CBPWM). Compared with traditional zero-level disassembly (ZD) method, the proposed FLA-based HPWM method maintains NP voltage balance while achieving higher system efficiency. Finally, the feasibility and effectiveness of the proposed optimization strategy are verified by simulation and experiment results.

Accurate thermal characterizations of power modules are beneficial for design and operation of power converters with the assistance of thermal models. However, the thermal coupling effects (TCEs) may degrade the performance of thermal models, and this becomes more pronounced in multi-chip power modules. To address this, a thermal model that enables to characterize different types of TCEs is presented in this paper. In the proposed thermal model, the properties of the classical thermal models are first provided. Then, different types of TCEs in multi-chip power modules are thoroughly analyzed. It is revealed from the analysis that the TCEs will affect the junction temperature distributions and heat flows, and distinct thermal behaviors are observed with different TCEs. Afterward, the thermal parameters including the self-thermal parameters and the coupling thermal parameters are extracted, and accordingly, the proposed thermal model is obtained. With the proposed thermal model, accurate thermal characterizations for multi-chip power modules are performed. Finally, taking typical insulated-gate bipolar transistor (IGBT) modules as a case study, the validity of the proposed thermal model under various conditions is confirmed through extensive experimental testing.

This paper investigates the interoperability of un-symmetrical transmitter (Tx) and receiver (Rx) coil geometries for wireless charging of unmanned aerial vehicles (UAVs). It evaluates the coupling performance of circular, double-D (DD), and bipolar (BP) coil structures under various excitation modes to identify configurations that minimize sensitivity to misalignment. The study analyses BP coils under both 0° and 180° excitation modes and DD coils in a conventional configuration. Finite element analysis (FEA) using Ansys Maxwell and experimental validation through hardware implementation were conducted to examine magnetic coupling across air gaps (10 to 100 mm) and lateral misalignments (±250 mm). The interoperability assessment identified the circular Tx-Rx coil pair as the most robust solution, achieving a nominal coupling coefficient (k ≈ 0.2) at a 50 mm air gap with misalignment tolerance of ±50 mm in both x and y directions. BP (0°) excitation mode demonstrated improved misalignment tolerance but required a reduced air gap for optimal coupling, while DD configurations showed stronger coupling along specific misalignment axes but were more sensitive to positional deviations. The findings emphasize the importance of coil geometry and excitation mode in enhancing UAV wireless charging performance. This research provides comprehensive guidelines for optimizing Tx-Rx coil interoperability, with the circular coil pair emerging as the most effective design for stable and efficient power transfer under real-world misalignment conditions.

This paper introduces an enhanced non-isolated DC-DC converter with high voltage gain capability for efficient power conversion. The proposed configuration achieves significant voltage gain with minimal components, ensuring optimal performance under various operating conditions. In particular, it maintains a common ground between the input and output, enhancing safety and reliability. Furthermore, the design offers high efficiency, balanced voltage and current distribution, reduced stress on switching devices, and effectively minimizes voltage fluctuations. These attributes make it a highly suitable solution for various power conversion applications. The paper provides a comprehensive analysis of converter key waveforms, operating principles, steady-state behavior, and design equations. The voltage conversion ratio, as well as voltage and current stress, is derived and compared with other converters in the literature. To validate the proposed converter design, a 400 W prototype was developed and successfully tested, demonstrating efficient voltage conversion from 32 V to 400 V.