采用通用生成函数法的自治微网旋转备用充裕性评估

自治微网中可再生能源的随机波动特性对旋转备用容量的运行规划提出了新的要求。基于通用生成函数法(UGF),结合马尔可夫技术建立了自治微网内各元件的多状态概率预测模型,提出了自治微网旋转备用概率预测充裕性评估方法与流程。模型综合考虑了风速、光照强度的预测不确定性,以及风机、光伏系统的随机故障特性和拓扑结构。针对UGF处理多状态会产生组合爆炸问题,采用合并同类项、均摊法以及改进K-means聚类进行状态削减,以减小计算负担、提高计算速度。通过MATLAB编程对自治微网算例系统进行仿真分析,结果表明增大传统机组爬坡速率、合理设置光风容量以及初始储能状态有助于提升旋转备用裕度程度。

Adequacy Evaluation of Spinning Reserve for Autonomous Microgrids Based on Universal Generating Function Method

The random fluctuation characteristics of renewable energy in the autonomous microgrid put forward new requirements for the operating and planning of the spinning reserve capacity. Based on the universal generating function(UGF)method and the Markov technique, a multi-state probability prediction model for each component in the autonomous microgrid is developed. And the probabilistic prediction based evaluation method for the spinning reserve adequacy of autonomous microgrid and its flow are proposed. The inherent characteristics of components and renewable energy are incorporated when modeling, including the uncertainty of the wind speed and the light intensity, the random failure characteristics and the topology of the wind turbine and photovoltaic system. In view of the UGF method for dealing with multi-state may generate combinatorial explosion, merging like terms, an apportion method and a K-means clustering technique are utilized to reduce the amount of states and improve the computing speed. The proposed models are applied to a microgrid test system and the simulation calculation is performed by programming in MATLAB. The results show that increasing the ramp rate of conventional units, setting reasonable wind and solar energy capacities and the initial energy storage condition can help improve the degree of spinning reserve adequacy. This work is supported by National Natural Science Foundation of China(No. 51377162)and Fundamental Research Funds for the Central Universities(No. 1081-15056187).