【作者】 吴翔宇； 沈沉； 赵敏； 李凡； 马红伟； 吕斌；

【Author】 Xiangyu Wu;Chen Shen;Min Zhao;Fan Li;Hongwei Ma;Bin Lv;State Key Lab of Power Systems, Dept. E.E, Tsinghua University;XJ ELECTRIC CO.,LTD;

【机构】 电力系统及发电设备控制和仿真国家重点实验室,清华大学； 许继电气股份有限公司；

【摘要】 在微电网孤网运行系统中,传统下垂控制策略大多将频率引入控制中,但是在以纯逆变器接口的微电网中,系统功率的不平衡量难以通过频率来直接反映。本文根据微电网公共母线电压幅值(V),以及d轴电压与q轴电压的比值(rat)同微电网系统有功和无功不平衡量之间的关系,设计了P/V、Q/rat下垂控制策略。该控制策略能够使微电网在孤网运行时维持电压及频率稳定,并且使所有的分布式电源按照预先设定的下垂系数分配有功及无功功率。更多还原

【Abstract】 Frequency and voltage droop control is a general power control and load sharing strategy in islanded microgrids. However, when all distributed generation(DG) units are connected to the microgrid via power-electronic converters, the frequency deviation of the microgrid does not reflect the power imbalance in the microgrid. And the conventional droop control based on power- frequency relationship will not be functioning. This paper reveals that the PCC bus voltage magnitude(V) and the ratio(rat) of d-axis bus voltage to q-axis bus voltage are related to power imbalance in a power-electronic converter interfaced microgrid. And a P/V and Q/rat droop control method is proposed. With this control, the islanded microgrid can maintain stable voltage and frequency and all DG units can accurately share active and reactive loads according to preset ratios. Simulation results on an islanded microgrid in its steady-state and load-switching operation are given to verify the proposed method.更多还原