不平衡工况下交直流配电网非隔离变换器  

Transformerless Converter for AC/DC Distribution Network Under Unbalanced Conditions

作　　者：王磊[1] 张馨方 尹泽华 韩肖清[1] 任宇 WANG Lei;ZHANG Xinfang;YIN Zehua;HAN Xiaoqing;REN Yu(Shanxi Key Laboratory of Power System Operation and Control,Taiyuan University of Technology,Taiyuan 030024,China;Taiyuan Electric Power Supply Company,State Grid Shanxi Electric Power Company,Taiyuan 030001,China)

机构地区：[1]太原理工大学电力系统运行与控制山西省重点实验室,太原030024 [2]国网山西省电力公司太原供电公司,太原030001

出　　处：《高电压技术》2023年第11期4849-4858,共10页High Voltage Engineering

基　　金：山西省科技重大专项(20181102028)。

摘　　要：非隔离变换器具有高效、经济的优势,因此在低压交直流配电网中具有广阔的应用前景,但漏电流及供电质量低的问题限制了非隔离变换器的推广应用。为此,通过构建变换器的共模等效电路,对传统四桥臂变换器进行改进,得到一种无漏电流的共地型四桥臂变换器。在此基础上,分析不平衡工况下直流侧二倍频波动及基频共模波动机理,并提出共地型四桥臂拓扑的多目标复合控制策略。最后,经dSPACE实验平台进行对比验证,研究结果表明:采用所提共地型四桥臂拓扑及复合控制策略,漏电流得到了有效抑制,双极直流母线电压保持稳定,实现了低压交直流配电网的安全稳定运行。研究结果证明了所提策略的有效性。Transformerless converter has higher transmission efficiency and lower cost,thus it has broad prospects for application in low-voltage AC/DC distribution networks.However,the problems of leakage current and low quality of power supply limit the application of transformerless converters.Therefore,we constructed a common-mode equivalent circuit,and improved the traditional four-leg converter to obtain a common-ground four-leg converter without leakage current.Then,we analyzed the mechanism of DC-side diode and fundamental-frequency common-mode fluctuations under the condition of unbalanced load,and proposed the multi-objective composite control strategy of common-ground four-leg topology.Finally,the dSPACE experimental platform was used for comparison and verification.The results show that the proposed common-ground four-leg topology and composite control strategy can effectively suppress the leakage current and keep the bipolar DC bus voltage stable,thus realizing the safe and stable operation of the low-voltage AC/DC distribution network.The results prove the effectiveness of the proposed strategy.

关 键 词：低压交直流配电网 非隔离 漏电流 不平衡 共地型 复合控制 

分 类 号：TM46[电气工程—电器]