基于改进Apriori算法的直流闭锁受端断面越限调整策略

Adjustment Strategies Based on Improved Apriori Algorithm for Overloaded Transmission Section in Receiving-End Power Grid Under UHVDC Blocking Fault

当发生特高压直流闭锁故障时,会实施一系列调控措施填补受端电网的功率缺额。针对一、二次调频之后存在的断面越限问题,提出了一种基于改进Apriori算法的断面越限调整策略。首先,采用动态潮流算法进行闭锁故障仿真,根据灵敏度方法对断面越限进行调整,再提取调整信息,经过数据处理,形成机组、负荷调整策略和断面状态变化情况数据库。然后,对Apriori算法进行改进,将前项约束为机组、负荷调整策略,后项约束为断面状态变化情况,通过关联分析得到调整策略与断面状态变化情况之间的强关联规则。最后,对锦苏直流闭锁故障进行仿真及关联分析来验证所提方法的有效性,结果表明,改进后的Apriori算法大大减少了无效规则的产生,通过关联分析可得到对断面调整有效的强关联规则,为电网的断面越限调整提供决策依据。

Once blocking fault occurs in large-capacity ultra-high-voltage direct current(UHVDC) transmission system,a series of control measures are implemented to fill the power shortage of the receiving-end power grid.Focus on the problem of overloaded transmission sections after primary and secondary frequency modulation,this paper proposes an overloaded-section adjustment strategy based on the improved Apriori algorithm.Firstly,the blocking fault is simulated by the dynamic power flow algorithm and the transmission sections are adjusted by sensitivity method.Then,the adjustment information is extracted.After data processing,the database of unit,load adjustment strategy and section state change is set up.The Apriori algorithm is improved that fore-part item-set is restricted to be the unit and load adjustment strategy and rearpart item-set is restricted to be the change of the section state.The strong association rules between the adjustment strategy and the change of the section state are analyzed by improved Apriori algorithm.Finally,the simulation results of JinpingSuzhou DC fault and association analysis show that the improved Apriori algorithm greatly reduces the generation of invalid rules,and the strong association rules effective for section adjustment are extracted from association analysis,which provides decision-making basis for overloaded transmission section adjustment of the power grid.