基于改进蒙特卡洛法的智能电网实时运行风险评估

Real-time operation risk assessment of smart grid based on improved monte carlo method

蒙特卡洛法需使用大量电网抽样数据,花费的风险评估时间长,提出一种改进蒙特卡洛法实现高效智能电网实时运行风险评估。从多方面考虑,构建智能电网风险评价指标体系,明确蒙特卡洛法存在抽样次数多及方差系数大的问题;将交叉熵重要抽样法与分散抽样法相结合,构建近似函数,令原本电网中微小概率事件转换为大概率事件,减少算法抽样次数和方差系数,提高算法的计算效率。实验表明,所提方法能够有效识别正常状态下及元件失效条件下的电网实时运行风险,并通过失效线路负荷转移的方式有效降低了智能电网实时运行风险。

The Monte Carlo method requires a large amount of power grid sampling data,which takes a long time for risk assessment.An improved Monte Carlo method is proposed to realize real-time operation risk assessment of efficient smart grid.Considering from various aspects,the risk evaluation index system of smart grid is constructed,and it is clear that the Monte Carlo method has the problems of more sampling times and large variance coefficient.The cross entropy importance sampling method is combined with the decentralized sampling method to construct an approximate function,so that the small probability events in the original power grid can be converted into large probability events,reduce the number of sampling times and variance coefficient of the algorithm,and improve the calculation efficiency of the algorithm.The experiment shows that the proposed method can effectively identify the real-time operation risk of the power grid under normal conditions and component failure conditions,and effectively reduce the real-time operation risk of the smart grid by transferring the load of the failed line.