考虑系统风险的输电网线路除冰优化调度

Transmission Lines De-icing Optimal Scheduling Considering System Risk

为了降低冰灾期间系统的运行风险,提出一种输电网线路除冰优化调度模型。由气象预测与线路覆冰预测得到冰灾期间线路的冰风荷载,以应力?强度干涉模型为工具计算线路的时变强迫停运率,作为冰灾期间系统风险评估的元件停运模型。考虑系统的运行水平与线路覆冰厚度等约束,以线路除冰停运计划为变量,以除冰期间系统的电量不足期望值最小为目标函数,建立动态0-1整数优化问题,采用遗传算法进行求解。以IEEE-RTS系统为研究对象,设计两组基于经验的除冰方案与优化模型求解的方案并进行比较。结果表明,在三组方案均保证线路安全的前提下,优化模型求解的方案,使系统在除冰周期具有最小的风险水平。该模型可作为冰灾前制定除冰计划的工具。

A model of transmission lines de-icing optimal scheduling was proposed in this paper to reduce the system risk during the ice storm. The ice and wind loads on lines could be calculated by weather and icing forecast. The time-variable forced outage rates of lines could be calculated by the load-strength interference model and it was the component outage model to evaluate the system risk during the ice storm. Considering the ice thickness constraints and system operating level, a dynamic 0-1 integer optimization problem for transmission lines de-icing scheduling, which was with the variables of lines de-icing outage scheme and the objective function of minimizing the value of expected energy not supplied, was proposed and the genetic algorithm was used to solve the programming problem. The proposed model was tested on the IEEE-RTS, and two cases of empirical de-icing scheme were designed to compare with the de-icing scheduling solution solved by the proposed model. The results indicate that under the premise that all three cases guarantee lines’ safety, the proposed model gives an appropriate de-icing scheme with minimum system risk. This model can be used as a tool to develop the de-icing scheme before the ice storm.