计及电网停电风险的输电线路动态融冰决策方法

电网发生大面积冰灾情况时,多条输电线路存在覆冰故障隐患,电网稳定运行受到严重威胁,需要提前制定输电线路融冰方案,合理安排融冰顺序。针对此问题,分析输电线路覆冰继续运行给电网带来的停电风险,将与待融冰输电线路相关联的变电站的电气主接线展开,将传统削负荷模型改进后应用于输电网与变电站主接线的组合网络,建立断路器可靠性模型,计算靠后融冰线路因继续运行的电网停电风险;利用计及风速及降雨影响的输电线路覆冰增长预测模型,计算输电线路的覆冰率,根据覆冰率门槛值确定待融冰线路集,基于覆冰严重度模型构建系统全局的覆冰指数指标;综合考虑电网停电风险及系统全局覆冰指数建立输电线路融冰紧迫度指标,动态更新待融冰线路并决策融冰顺序。最后,以IEEE RBTS系统进行算例分析,验证了所提方法的可行性与合理性。

A dynamic ice melting decision method for transmission lines considering outage risk of power grid

Multiple transmission lines have the icing hidden fault when a large area of ice disaster happens to power grid, and the stable operation of power system will be seriously threatened. Therefore, the ice-melting scheme should be developed in advance to arrange the order of ice-melting reasonably. In order to analyze the outage risk of power grid caused by the continuous operation of icing-hidden transmission lines, it''s needed to expand the substation main electrical wiring, which is associated with the transmission line needing to melt ice. An improved cutting load model is proposed to assess power grid outage risk of the combination network of transmission grid and substation. And a breaker reliability model is set up to access the outage risk caused by the continuous operation of transmission lines which queue at the rear of ice-melting queue. Icing rate is calculated based on line icing growth model considering wind speed and rainfall, and the ice melting lines set is determined by the icing rate threshold. Power system global icing index is proposed based on icing severity model. Considering the outage risk of power system and global icing index, the ice melting urgent degree index is proposed to dynamically update the ice melting lines set, and determine the ice melting order. Finally, the feasibility and rationality of the proposed method is verified by taking IEEE RBTS as an example.