基于灵敏度分析微网孤岛运行下的频率控制器研究

Study on the Frequency Controller of Microgrid during Islanded Operation Based on Sensitivity Analysis

以微网孤岛运行时的稳定性分析为目标,将未来可再生电能的传输和管理网络作为研究对象,首先分别推导了固态变压器、网络线路以及负荷模型的状态空间方程,建立了相应环节的小信号模型,并引入了下垂控制器与电压电流双环控制器,建立了完整的微网小信号模型。其次对微网系统状态矩阵进行了特征值的关键性与一般性灵敏度分析,确定了影响系统稳定的环节和系统参数。通过分析结果得出电流环控制器参数对系统稳定性有影响,功率下垂控制器的下垂控制系数对系统稳定性有影响。对微网系统状态矩阵进行了特征值灵敏度分析,该分析方法对微电网系统频率控制器优化配置提供理论支持。

Targeting the stability analysis of microgrid during islanded operation and taking delivery and management of renewable electric energy in future as the research object, this paper, first of all, derives the state space equations of the solid state transformer （SST）, network line and load model respectively, and then establishes the small-signal model of the corresponding link, and droop controller, voltage-loop and current-loop controller are introduced to control the voltage and frequency, thus a complete microgrid small-signal model is established. Secondly, the parameters which affect the stability of system are determined according to the key and general eigenvalues and sensitivity of the state matrix analysis. The analysis concludes that both the parameters of the current-loop controller and the droop controller affect the stability of the microgrid system. The eigenvalue value sensitivity analysis is carried out for the state matrix of the micro grid system, pro- viding the theoretical support for the optimal allocation of the frequency controller of the micro grid system.