考虑不确定性的下垂控制微电网可达性分析

Reachability Analysis of Droop-controlled Microgrids Considering Uncertainty

针对下垂控制微电网中时刻存在的不确定因素,提出基于齐诺多面体的可达性分析方法,研究系统在不确定条件下的动态运行特性。首先采用齐诺多面体作为集合表达形式,描述系统中的不确定变量,并提出线性动态系统可达集的计算方法。随后基于下垂控制微电网的动态模型,对微电网算例进行仿真分析,并通过时域采样仿真验证了所提方法的有效性。结果表明,可达性分析方法仅需通过一次仿真计算,即可考虑各种不确定因素的持续叠加影响,给出系统所有可能运行轨迹的边界,确定系统频率、电压等状态变量的最大波动范围,从而分析系统在不确定条件下的安全稳定性。

Considering the uncertain factors in droopcontrolled microgrids, a reachability analysis method based on zonotopes was proposed to study the dynamic performance of the system under uncertainties. Firstly, zonotopes were used as set representation to describe the uncertain variables of the system, and the calculation method for reachable set of linear dynamic system was presented. Then, based on the dynamic model of the droop-controlled microgrid, simulation analysis was performed on a microgrid test system, and the effectiveness of the proposed method was verified by time domain sampling simulation. The results show that reachability analysis method can consider the continuous impact of various uncertain factors, compute the bounds of all possible dynamic trajectories and determine the maximum fluctuation range of state variables such as frequency and voltage by one single simulation, so as to analyze the system dynamic security and stability under uncertain conditions.