基于分布式两级控制的孤岛微网网络化控制策略

Networked Control Strategy of Islanded Microgrid Based on Distributed Secondary Control

针对传统微网下垂控制的网络化控制策略中数据传输随机丢包对系统控制精度和稳定性影响的问题,提出一种基于分布式两级控制的孤岛微网网络化控制方法。采用初级控制实现负荷分配,同时增加分布式次级控制部分弥补电压和频率偏差提高孤岛微网负荷分配精度并维持微网稳定,通过改进的分布式卡尔曼(Kalman)滤波估计微网电压与频率输出状态,可有效避免数据传输随机丢包对系统稳定性的影响。所提的控制策略可实现二次型性能指标的全局最优控制,且对较小程度的数据丢包率具有鲁棒性。仿真实验验证表明,所給出的控制方法是有效可行的。

Considering the influence of random data transmission packet loss on control precision and stability of microgrids when the networked control strategy of conventional droop control scheme is adopted, a method of networked control strategy of islanded microgrid based on distributed secondary control is proposed. The primary control part is used to achieve the load distribution, and the distributed secondary control part is used in the voltage and frequency restoration to improve the accuracy of load distribution and maintain the stability of the islanded microgrid. An improved distributed Kalman filter is proposed to estimate the output states of voltage and frequency in microgrid, which can effectively avoid the influence of random data packet loss on system stability. The proposed control strategy can realize the global optimal control based on quadratic performance index, and it is robust to the smaller data packet loss rate. Simulation results show that the proposed control method is effective and feasible.