单-双极运行方式转换直流电力电子变压器的启动策略研究

直流电网技术的各类场景,均存在实现各类功能的直流型电力电子变压器。分布式/集中式的新能源电站自身的单极性直流输出,与外部连接的双极性电网之间,需要一种专用的单-双极运行方式转换直流电力电子变压器,用以匹配两者运行方式的差异。本文基于双向有源全桥电路,给出一种应用于该场景下的具体实现方案。在分析其电路拓扑、工作原理、控制策略基础上,设计出一套功率30k W,输入150V转换为±150V的单-双极运行方式转换直流电力电子变压器。针对不同的工况下外部条件不同以及控制目标差异,对变压器启动过程进行研究,并设计相应的启动控制策略。仿真与实验结果均证明了理论分析的正确性和有效性。

Startup strategy of monopolar-to-bipolar DC-type power electronic transformer

In the DC network,different DC-type power electronics transformers are required for different functions.The centralized/distributed renewable energy generation station is usually with monopolar configuration,which leads to the mismatch with the outside DC grid with the bipolar configuration.Therefore,a particular monopolar-to-bipolar DC-type power electronic transformer,M2B DC-PET,is needed to serve as interface between renewable energy generation station and DC grid.A detailed implementation scheme has been given in this paper,of which the rated transmission power is 30kW and rated voltage is 150V transformed into ± 150V.On the basis of theoretical analysis,corresponding startup strategies is designed according to the different scenarios.Both simulation and experimental results validated both the correctness and effectiveness of the theoretical analysis and discussion results on the proposed M2B DC-PET.