基于PMU的同步定频微网孤岛运行控制策略

PMU-based Constant-frequency Synchronous Control Method for Islanded Microgrid

针对微网孤岛运行采用下垂控制时造成的频率偏差、功率无法精确分配问题,提出一种基于PMU的同步定频微网孤岛运行控制策略。以PMU秒脉冲为同步参考信号,计算生成统一参考坐标系的实时旋转相角。基于此相角对各节点可调度型分布式电源逆变器进行同步控制,使其输出频率固定、相位相同的电压。根据各测点PMU同步功率量测信息,结合各分布式电源额定容量占比,对逆变器输出电压进行二次调整,实现各分布式电源输出功率的精确分配。通过建立传递函数、绘制根轨迹对逆变器功率控制参数进行分析和设计。利用Matlab/Simulink时域仿真模型和微网实验平台共同验证了所提策略的可行性和有效性。

In order to solve the problem of frequency deviation and power imprecision distribution caused by droop control in islanded microgrid,a PMU-based constant-frequency synchronous control method was proposed.Taking the PMU second pulse as the synchronous reference signal,the real-time rotation phase angle of the unified reference coordinate system was generated.Based on this phase angle,the dispatchable distributed generation inverter of each node was controlled synchronously to export the voltage with fixed frequency and the same phase.According to the PMU synchronous power measurement information of each measuring point,combined with the rated capacity proportion of each distributed generation,the output voltage of the inverter was secondary adjusted to realize the accurate distribution of the output power of each distributed generation.The power control parameters of inverter were analyzed and designed by establishing transfer function and drawing root locus.The feasibility and effectiveness of the proposed strategy was verified by Matlab/Simulink time-domain simulation model and microgrid experimental platform.