基于统一控制策略的光伏微网控制器参数敏感性分析

Parameter Sensitivity Analysis of Controller Based on Unified Control Strategy in Photovoltaic Microgrid

针对低压光伏微网中逆变器的控制,设计了一种基于统一控制策略的控制器,能够避免微网在并网和孤岛两种运行方式间切换时控制策略的转换,实现不同运行模式间的平滑切换及光伏微源功率均分。对传统的下垂控制进行改进,在传统下垂控制的基础上引入一个功率PI补偿器。根据阶跃响应动态指标和稳定性要求,利用根轨迹法优化设计控制器参数。最后,在Matlab/Simulink环境下进行了仿真,结果验证了所设计的控制器的可行性和有效性。

A controller based on unified control strategy for the DC/AC converters in a low-voltage photovoltaic micro-grid（PV-MG） is proposed for both grid-connected and islanding mode operation and seamless switching as well as power sharing of the PV generators, which can avoid using two different control strategies when the PV-MG operates at grid-connected or islanding mode. The unified controller is designed by combining the power PI compensator with droop control, and can realize the automatic and seamless switching between the two modes of PV-MG. According to the step response dynamic index and stability constraints, the parameters of the controller are optimized with root locus methods. The Matlab/Simulink simulation results verfy the feasibility and effectiveness of the proposed controller.