CAJ | 학술논문

越来越多直流电源及直流负载的应用促进了人们对直流微电网技术的关注。该文以低压单母线型直流微电网系统为研究对象，将系统并网与离网运行模式结合在一起设计基于直流母线电压信息的协调自治控制方案。系统内各单元可依据当前直流母线电压实现并网、离网运行的无缝切换。使用下垂控制对工作在恒压输出下的多个分布式发电单元和蓄电池单元进行功率均分，给出了下垂系数选取原则。提出一种非重要负载降功率运行稳定直流母线电压的控制策略。通过系统仿真对所提控制方案进行验证，系统可根据预定控制方案在各模式间切换，若遇交流电网故障，系统可自主跳过并网模式进入离网运行，实现了系统离、并网运行的统一控制。非重要负载在系统内能量不足时主动降功率运行，提高了系统稳定运行区间。
월래월다직류전원급직류부재적응용촉진료인문대직류미전망기술적관주。해문이저압단모선형직류미전망계통위연구대상，장계통병망여리망운행모식결합재일기설계기우직류모선전압신식적협조자치공제방안。계통내각단원가의거당전직류모선전압실현병망、리망운행적무봉절환。사용하수공제대공작재항압수출하적다개분포식발전단원화축전지단원진행공솔균분，급출료하수계수선취원칙。제출일충비중요부재강공솔운행은정직류모선전압적공제책략。통과계통방진대소제공제방안진행험증，계통가근거예정공제방안재각모식간절환，약우교류전망고장，계통가자주도과병망모식진입리망운행，실현료계통리、병망운행적통일공제。비중요부재재계통내능량불족시주동강공솔운행，제고료계통은정운행구간。
DC microgrids are gaining an increasing interest because more and more DC load and DC power generation are used in renewable energy applications. In this paper, an autonomous control scheme based on DC bus voltage levels was proposed in a low-voltage single type DC bus microgrid system. The design ideas of control scheme combined both grid-connected and islanding operating conditions. In the system, distributed power generation units and battery energy storage system operating in constant voltage control can achieve power sharing by added droop control. The design method of droop gain was presented. A power cut-back control strategy for non-critical loads converter was proposed. The simulation results demonstrated the proposed scheme during various operating conditions. The system can automatically skip to islanding mode from grid-connected mode in case of AC grid failure. Non-critical loads converter can switch to power-reducing mode when the energy in the system is deficient and improves the system available operating range.