针对含高比例分布式电源的双极性直流配电系统所面临的极间均衡控制与电能质量问题,本文提出一种基于前端电流平衡器的解决方案.该方案通过在每一用户所对应的公共连接点处配备电流平衡电路,实现配电网内任意用户节点的正/负极电流均衡控制,进而实现全网正负极对称运行.在此基础上本文提出一种适用于双极性低压直流配电网的前端电流平衡器拓扑及其控制策略,并给出基于P/N型Boost电路的分布式发电单元并网架构,形成具体的分布式直流电源双极性接入技术方案.该方案一方面可实现分布式电源与直流型负载的高效率、灵活化接入;另一方面可以保证任意用户与配电网正/负极线路间交换电流相等,保证可再生能源高渗透率接入条件下直流双极间均衡运行.针对正/负极侧分布式电源功率失衡典型工况,仿真结果表明理论分析正确可靠.该方案在未来分布式直流配电系统中具备潜在应用价值.%In order to cope with technical challenges of bipolar balancing and power quality issues of DC distributed system, a new solution based on front-end current balancer ( FECB) has been proposed in this paper, which will be operated in the scenario of high percentage distributed generation ( DG ) . The positive- and negative-line cur-rents for each user node could be balanced by installing FECB at each corresponding PCC. The whole system will be operated symmetrically under an ideal network condition. A novel FECB topology has been further proposed to-gether with corresponding strategy. For DG integration with bipolar DC distribution system, a detailed solution is given on the basis of P/N-type Boost converters. In this scheme, both high efficiency flexible integration of DG u-nits and balanced line currents on each user node can be obtained in order to guarantee the symmetrical operation of distribution system. All theoretical results have been validated by simulation. The proposed scheme has a potential application value in future DC distribution system and DC integration of renewable energy.
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