刘海霞,李 岚,叶吉亮,王宇龙.改善功率分配及电能质量的微电网分层控制策略[J].电测与仪表,2018,55(18):37-43. Liu Haixia,Li Lan,Ye Jiliang,Wang Yulong.Hierarchical Control Strategy of Islanded Microgrid to Improve Power Distribution and Power Quality of Islanded Microgrid[J].Electrical Measurement & Instrumentation,2018,55(18):37-43.
改善功率分配及电能质量的微电网分层控制策略
Hierarchical Control Strategy of Islanded Microgrid to Improve Power Distribution and Power Quality of Islanded Microgrid
For two parallel inverters in islanded microgrid, because they are influenced by the line impedance, the traditional droop control cannot be utilized to achieve accurate power in proportion for different micro source. In order to im-prove the accuracy of reactive power distribution, the paper deeply analyzes the influence of total impedance on load power distribution, and points out that the necessary and sufficient condition to realize reasonable power distribution is that the total impedance must be inversely proportional to its rated capacity. Therefore, a hierarchical control strategy for microgrid is proposed. The first layer designs a virtual impedance based on a rotating coordinate system not only to eliminate the coupling phenomena between active power and reactive power in the microgrid, but also to improve reactive power distribution performance; The central controller in second layer provides reactive power feedback to the first layer to further achieve no difference distribution of reactive power. In addition, the system frequency and common bus voltage are adjusted to optimize the power quality. The parallel model of two mi-cro-source is built in Matlab / Simulink simulation platform. The simulation results prove the correctness and feasi-bility of the control strategy.
