基于条件风险价值的风柴储孤岛微网经济风险评估

Economic risk assessment of wind-diesel-storage islanded microgrid based on conditional value at risk

基于条件风险价值方法提出风柴储孤岛微网经济风险评估模型。对孤岛微网中风机与柴油发电机故障情况进行抽样,结合其出力分别建立可靠性模型;综合考虑储能放电深度和充放电次数对储能容量衰减的影响以及储能运行策略,建立储能系统可靠性模型;考虑微网内不同重要程度负荷停电造成的经济损失,采用条件风险价值方法定义经济风险严重度指标;采用蒙特卡洛模拟法求解严重度指标计算公式中的停电损失概率密度函数。以欧洲典型低压孤岛微网为例,对不同风机装机容量、负荷峰值、一般负荷容量占比以及置信度下的严重度指标进行分析,验证了该指标的合理性。

An economic risk assessment model of wind-diesel-storage islanded microgrid is proposed based on CVaR(Conditional Value at Risk).The fault conditions of wind turbines and diesel generators in isolated microgrid are sampled,and the reliability models are established in combination with their outputs.A reliability model of energy storage system is established,which comprehensively considers the influence of discharge depth and charge/discharge times of energy storage on the attenuation of energy storage capacity and the operation strategy of energy storage.Considering the economic loss caused by load blackout of different important degrees in microgrid,the CVaR method is adopted to define the economic risk severity index.Monte Carlo simulation method is used to solve the probability density function of blackout loss in the calculation formula of severity index.The typical low voltage isolated microgrid in Europe is taken as an example to analyze the severity index under different wind power installed capacities,load peakvalues,general load capacity proportions and confidence degrees,which verifies the rationality of the index.