协调经济性及电压稳定性的受端系统紧急负荷控制优化方法  

Optimization Method for Emergency Load Control of Receiving-end System Considering Coordination of Economy and Voltage Stability

作　　者：孙大雁[1,2] 周海强 鞠平[1] 周荣玲[1] 苏大威[2] 徐春雷 

机构地区：[1]河海大学能源与电气学院,江苏省南京市210098 [2]国网江苏省电力公司,江苏省南京市210024

出　　处：《电力系统自动化》2017年第17期106-112,共7页Automation of Electric Power Systems

基　　金：国家电网公司科技项目(SGJS0000DKJS1501031)~~

摘　　要：特高压直流逆变站闭锁后,应在确保受端系统安全稳定的前提下尽量减小紧急控制的经济代价,同时,为了使逆变器尽快恢复正常运行,控制后的系统还需要提供足够的无功支撑,为此提出了一种协调经济性及电压稳定性的受端系统紧急负荷控制优化方法。首先,讨论了事故发生后受端系统的动态响应,提出根据电压薄弱性指标识别受端系统的若干电压薄弱节点,将其电压跌落量的平方和作为电压稳定性指标;然后,计算控制方案对应的负荷损失及事故罚款,将两者之和作为经济指标。为克服分段优化问题的求解困难,首先将分段的事故罚款曲线进行了近似光滑处理;然后,在考虑频率、电压及潮流等约束条件的基础上,以经济性、电压稳定性指标的加权和最小为目标,构建紧急负荷控制优化问题的数学模型,并应用原对偶内点法快速求解;最后,以含高压直流输电的IEEE 10机39节点系统为例,对算法进行了验证。结果表明,协调经济性及电压稳定性的优化控制可在不增加经济代价的前提下,改善控制后系统的电压稳定性,有助于逆变站恢复运行。When the ultra-high voltage direct current converter station is blocked,the cost of emergency load control of the receiving-end power system should be reduced as much as possible on the premise of security.Meanwhile,the receiving-end should also have sufficient reactive power support for the recovery of the inverter.An optimization method for emergency load control with economy and voltage stability coordinated is proposed.Firstly,the dynamic responses of the receiving-end system are analyzed when blocking accidents occur.The voltage vulnerability index can be used to identify the most vulnerable load nodes.The sum of squares of voltage dips of these nodes is taken as an index of voltage stability.Then,the cost of lost loads and penalties made are calculated.The total cost of emergency control is taken as the economy index.The piecewise linear penalty curves are approximated with polynomials to facilitate the optimization of sectional problems.Secondly,the emergency load control optimization problem is modeled under the constraints on frequency,voltage,maximum transmission power,etc.The objective is to minimize the weighted sum of economical and voltage stability indexes.The primal-dual interior point method is chosen to solve this problem for its fast speed.Finally,the algorithm is applied in the modified IEEE 10-generator39-bus system with two high voltage direct current transmission lines to verify its effectiveness.Simulation results show that the voltage stability is improved while the cost of control remains unchanged.And the coordinated optimal load control is beneficial to inverter recovery.

关 键 词：高压直流输电 紧急负荷控制 电压薄弱性 原对偶内点法 

分 类 号：TM712[电气工程—电力系统及自动化] TM721.1