The step-up resonant converters are widely adopted to provide high voltage in kV-level for electric propulsion system due to their high efficiency, low mass, modularisation, and high-power density. The bipolar Cockcroft-Walton voltage multiplier (BiCWVM) is a major circuit that steps up the voltage in the resonant converter. However, the diode non-linearity in BiCWVM can introduce self-sustained quasi-periodic oscillations in the voltage and current waveforms, which is commonly known as the Deane and Hamill (DH) phenomenon. The oscillation can lead to higher magnetic loss and control failure, and it is more likely to present in the gallium nitride-based converter due to the high-frequency operation. The authors aim to investigate and mitigate the DH phenomenon systematically so that proper mitigation can be implemented. To facilitate the investigation, the circuit before the BiCWVM in the converter is derived and modelled as a voltage source v_m and a series inductor L_sy. Also, the reverse recovery process of the diode in the BiCWVM can be represented by a piecewise-linear (PWL) model, with the simplified circuit and PWL model, the relationship between voltage and current under different operating conditions can be determined with ease. The relationship allows to understand the mechanism of diode reverse recovery in BiCWVM that leads to DH phenomenon. Finally, a hybrid-/full-silicon carbide (SiC) design is proposed to mitigate the DH phenomenon, which is verified experimentally for a 300-kHz, 5-W, 20-V/1.5-kV GaN-based step-up resonant converter.

中文翻译：

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电力推进系统应用氮化镓高压电源中迪恩和哈米尔现象的缓解

升压谐振变换器因其高效率、低质量、模块化和高功率密度而被广泛采用，为电力推进系统提供kV级高压。双极科克罗夫特-沃尔顿电压倍增器（BiCWVM）是谐振转换器中升压的主要电路。然而，BiCWVM 中的二极管非线性会在电压和电流波形中引入自持准周期振荡，这通常称为迪恩和哈米尔 (DH) 现象。这种振荡会导致更高的磁损耗和控制故障，并且由于高频工作，更容易出现在氮化镓基转换器中。作者的目标是系统地调查和缓解 DH 现象，以便实施适当的缓解措施。为了便于研究，转换器中 BiCWVM 之前的电路被导出并建模为电压源v _m和串联电感器L _sy。此外，BiCWVM中二极管的反向恢复过程可以用分段线性（PWL）模型来表示，通过简化的电路和PWL模型，可以轻松确定不同工作条件下电压和电流之间的关系。该关系有助于理解 BiCWVM 中二极管反向恢复导致 DH 现象的机制。最后，提出了一种混合/全碳化硅 (SiC) 设计来减轻 DH 现象，并在 300kHz、5W、20V/1.5kV GaN 基升压谐振器中进行了实验验证。转换器。