敏感负荷电压凹陷敏感度不确定性最大熵评估

Sensitivity Uncertainty Assessment of Sensitive Equipment Due to Voltage Sag Based on Maximum Entropy Principle

敏感负荷对电压凹陷的敏感度是时空变量,受供电侧电压凹陷幅值、持续时间、频次以及负荷特征、功能、运行状态等多因素影响,存在很大的不确定性。客观准确评估敏感负荷电压凹陷敏感度是研究的热点和难点。现有概率评估法基于大量样本,主观假设其敏感等级与随机分布规律后进行评估,不同的假设对评估结果影响很大。针对现有评估法的不足,提出用以电压凹陷对敏感负荷产生影响的严重性指标为随机变量,在样本数较少的情况下,根据最大熵原理求得不依赖于主观假设的负荷敏感度随机分布规律,通过概率密度函数的累积求和对敏感负荷故障率进行评估的新方法。给出了详细的最大熵模型及其求解方法,提出了具体评估过程,以PC机为例进行了仿真评估,并与现有4种概率评估法进行了比较,结果表明提出的方法不需主观假设,在样本数比较少的情况下,评估结果具有较好的准确性与适用性。

Aimed at overcoming the shortcoming of the current stochastic assessment of equipment sensitivity,an effective new method was proposed which use the voltage sag severity index of each type equipment as stochastic variable and search its objective probability density function based on maximum entropy principle.Then the equipment sensitivity was described by equipment failure rate through cumulative summing method.The detailed stochastic assessment principle and solution method was proposed also.The simulatio...