适用于直流微网系统的新型双向三端口变换器及其控制策略

Novel Bidirectional Three Port Converter andIts Control Strategy for DC Microgrid System

在传统分布式新能源并网接口中增加储能装置作为第三端口,可有效改善因分布式新能源强不确定性和随机性等特征引发的输出功率波动问题。为此提出并研究了一种适用于高升降压比直流微网系统的新型非隔离双向三端口变换器及其控制方法。通过集成双有源半桥变换器和非隔离双向Buck/Boost变换器,实现了三个端口中任意两个端口之间功率的双向传输。详细分析了所提新型变换器的工作原理、变换器输出特性以及控制策略,通过移相+脉宽调制控制方法,实现了宽范围的电压调节和各端口间功率的平滑切换。搭建了一台1 kW的试验样机,验证了所提出的新型三端口变换器及其控制方法的可行性和有效性。研究结果对于提高分布式新能源接入稳定性具有理论指导与工程实践借鉴意义。

Adding an energy storage device as the third port in the traditional distributed new energy grid connection interface can effectively improve the output power fluctuations caused by the strong uncertainty and randomness of distributed new energy.In this article a novel non-isolated bidirectional thre-port converter and its control method suitable for high rise to drop ratio DC microgrid systems was proposed and studied.By integrating a dual active half bridge converter and a non-isolated bidirectional Buck/Boost converter,bidirectional power transmission between any two of the three ports was achieved.A detailed analysis was conducted on the working principle,output characteristics,and control strategy of the proposed new converter.Through phase shifting plus pulse width modulation control methods,a wide range of voltage regulation and smooth power switching between various ports were achieved.A 1 kW experimental prototype was built to verify the feasibility and effectiveness of the proposed new three port converter and its control method.The research results obtained in this article have theoretical guidance and engineering practical reference significance for improving the stability of distributed new energy access.