Gallium nitride high electron mobility transistors (GaN HEMTs) have emerged as a promising class of power semiconductor switching devices due to their superior characteristics, and have been widely used in the applications requiring high frequency, high efficiency, and high power density. Despite these advantages, the low parasitic capacitance of GaN HEMTs makes them highly sensitive to the parasitic inductances in high-frequency circuits, leading to switching oscillations. These oscillations can induce adverse effects, including voltage and current overshoots, false triggering, electromagnetic interference, crosstalk, and additional power losses. A comprehensive review of GaN HEMTs is provided, focusing on their operational principles and electronic characteristics. It further examines the impacts of various parameters and discusses widely adopted methods for oscillation suppression. The aim is to offer practical insights for the design and optimization of GaN HEMT-based power systems.
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High-performance microprocessors have rapidly evolved and become ubiquitous in modern society. However, their power supply has become a significant factor limiting their overall performance. A power delivery module, known as a voltage regulator module (VRM), is required to provide high voltage, low current, and a fast transient response to meet microprocessor demands. An interleaved parallel-buck converter is suitable for VRM applications. Selecting an appropriate control strategy for the interleaved converter can help achieve high precision and fast response, thereby optimizing performance. First, the operating principles of interleaved parallel converters are analyzed. The relationship between the number of phases and conversion efficiency is also examined. Subsequently, commonly employed control techniques for interleaved converters are reviewed, discussing their respective advantages and limitations, along with an analysis of their suitability for phase-shedding strategies. A phase-shedding technique for interleaved converters is then introduced. Finally, the shortcomings of current control approaches for interleaved buck converters are outlined, and potential future research directions are suggested. These insights aim to enhance control performance and advance practical engineering applications.
During wireless charging, misalignments commonly occur in the transmission between the transmitting and receiving pads, including misalignments in the forward, backward, lateral and vertical directions. Unavoidable misalignments can result in changes in system parameters, thus affecting charging performance. A novel diagonally crossed solenoid magnetic coupler (DCSMC) is developed as a solution. The DCSMC integrated into a wireless power transfer (WPT) system with a hybrid topology enables superior misalignment tolerance in the X, Y, Z and XY diagonal directions while maintaining load-independent voltage output characteristics. A simplified parameter design method is developed to optimize the misalignment tolerance performance of a hybrid WPT system in multiple directions. Finally, a hardware prototype of a WPT system is constructed with an operating frequency of 200 kHz and a power of 200 W. The experimental results show that the hybrid WPT system, operating under loads from 40 Ω to 80 Ω, can tolerate misalignments of ±90 mm (40.9%) in both the X and Y axes, maintaining as small as a 5% fluctuation in output voltage. In addition, the WPT system can handle a maximum vertical displacement of +40 mm along the Z-axis and XY-diagonal misalignments of ±40 mm (12.8%).
Open Access
Issue
In today’s fast-paced, information-driven world, data centers can offer high-speed, intricate capabilities on a larger scale owing to the ever-growing demand for networks and information systems. Because data centers process and transmit information, stability and reliability are important. Data center power supply architectures rely heavily on isolated bidirectional DC-DC converters to ensure safety and stability. For the smooth operation of a data center, the power supply must be reliable and uninterrupted. In this study, we summarize the basic principle, topology, switch conversion strategy, and control technology of the existing isolated bidirectional DC-DC converters. Subsequently, existing research results and problems with isolated bidirectional DC-DC converters are reviewed. Finally, future trends in the development of isolated bidirectional DC-DC converters for data centers are presented, which offer valuable insights for solving engineering obstacles and future research directions in the field.
Open Access
Issue
Modern eco-friendly industries such as renewable energy systems, electric vehicles (EVs), and light-emitting diodes (LEDs) have led to technological advancements in power electronics. Switching-based power converters have limited working ranges and can cause significant harmonics and oscillations in the output voltage and current. Introducing variable inductors can help solve this problem by changing the inductance without resorting to extreme switch duty cycles. Despite their advantages, there is still a lack of comprehensive reviews of variable inductor applications in power converter design. A thorough and in-depth review of variable inductance control in power conversion is presented, including its significance, working principle, core structure, modeling method, and typical applications. Traditionally, an inductor works in its linear magnetic region; its inductance in a power converter is considered constant, and the converter operates under fixed working conditions. However, a broad range of working conditions is required for power converters in practical applications. This is typically realized by changing the duty cycles of the switches. The working principle of variable inductance is reviewed, and the application of variable inductance control in power converters is presented, which will further help power electronics researchers and engineers design flexible and resilient power converters.
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