一种考虑短路电流指标的动态等值方法  

Dynamic equivalence based on short circuit current index

作　　者：翁华[1] 徐政[1] 

机构地区：[1]浙江大学电气工程学院,浙江杭州310027

出　　处：《电力自动化设备》2012年第9期85-89,100,共6页Electric Power Automation Equipment

基　　金：国家高技术研究发展计划基金资助项目(863项目)(2011AA05119)~~

摘　　要：短路电流反映了交流系统的强度,为了简化原系统并保留原系统的短路电流特性,提出了一种考虑短路电流指标的动态等值方法。首先将外部系统根据机组的同调性划分为若干外部等值子系统,然后将短路电流作为等值过程中的一个重要量化指标,利用改进的Ward等值法对每个等值子系统化简,最后根据外部系统中的发电机与边界母线的电气距离来确定等值发电机的参数。算例表明,所提出的动态等值方法不仅能使等值前后研究系统的对称和不对称短路电流完全一致,还非常好地保留了原系统动态特性。Short circuit current reflects the strength of AC system.A method of dynamic equivalence considering the short circuit current index is proposed to simplify the original system while retain its short circuit current characteristics.The external system is divided into several subsystems according to the coherency of generators,the modified Ward method with the short circuit current as an important index in the equivalence process is then applied to simplify each subsystem,and the parameters of the equivalent generator are calculated according to the electrical distance between external generator and boundary bus.Simulative results show that,both the symmetric and asymmetric short circuit currents before and after the equivalence are consistent and the dynamic characteristics of the original system are well reserved.

关 键 词：电力系统 Ward等值法 短路电流 同调等值法 电气距离 

分 类 号：TM712[电气工程—电力系统及自动化]