A modular structured 12-kW resonant converter with effective zero voltage switching (ZVS) is proposed to integrate renewable energy lower voltage source to the microgrid. In this study, duty cycle control is adopted until ZVS fails and thereafter, sequential and parallel adjustment of duty cycle and the switching frequency is proposed for effective output voltage regulation. The proposed control logic ensures ZVS and output voltage regulation over wide load range even at very light loads compared to conventional control methods. Further, it maintains very high system efficiency with narrow range of frequency operation. Hence, it is easy to implement using a conventional digital controller. To minimise ripple current, each of the four converters is provided with phase delayed gate pulses under the proposed control scheme. This study presents an optimal design of the tank circuit elements assimilating high permeable powder cores to reduce magnetic loss and operation with IGBT switches at an optimum point to reduce conduction loss for enhanced system efficiency. A 12-kW, 400–1600 V developed prototype is tested and experimental results are discussed.

中文翻译：

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直流微网高效双控模块化谐振变换器的设计与实现

提出了一种具有有效零电压开关（ZVS）的模块化结构的12 kW谐振转换器，以将可再生能源低压电源集成到微电网。在这项研究中，采用占空比控制直到ZVS失效，然后，建议对占空比和开关频率进行顺序和并行调整，以实现有效的输出电压调节。与常规控制方法相比，即使在非常轻的负载下，所提出的控制逻辑也可确保在较宽的负载范围内实现ZVS和输出电压调节。此外，它在狭窄的频率范围内保持了很高的系统效率。因此，使用常规的数字控制器很容易实现。为了最小化纹波电流，四个转换器中的每一个都配有相位延迟的门脉冲在建议的控制方案下。这项研究提出了一种油箱电路元件的最佳设计，该油箱电路元件吸收了高磁导率的压粉磁芯以减少磁损耗，并且在最佳点使用IGBT开关进行操作以减少传导损耗，从而提高了系统效率。测试了一个12kW，400–1600 V的开发原型，并讨论了实验结果。