This article presents a bidirectional nonisolated dc–dc converter based on switched-capacitor converters intended for electric railway system applications. It consists of plural main converters with two power devices per converter, plural auxiliary converters each of which is formed by cascaded chopper cells, and small-sized inductors for current control. The dc–dc converter can achieve zero-current switching (ZCS) for all power devices used in the main converters under arbitrary load conditions and an arbitrary voltage ratio of high-voltage-side voltage and low-voltage-side voltage. Consequently, square-wave currents can be removed from both the high- and low-voltage sides of the converter. The validity of the operating principles as well as the control methods proposed in this article is verified by experiments using a 200-V, 2-kW downscaled model.

中文翻译：

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基于开关电容转换器的双向非隔离式DC-DC转换器的控制和实验验证

本文介绍了一种基于开关电容转换器的双向非隔离式DC-DC转换器，旨在用于电气铁路系统应用。它由多个主转换器组成，每个转换器具有两个功率器件，多个辅助转换器（每个均由级联斩波单元组成）和用于电流控制的小型电感器组成。dc-dc转换器可以在任意负载条件下以及高压侧电压和低压侧电压的任意电压比下，对主转换器中使用的所有功率器件实现零电流开关（ZCS）。因此，可以从转换器的高压侧和低压侧都去除方波电流。通过使用200V电压进行的实验，验证了本文中提出的工作原理以及控制方法的有效性。