基于故障模型的环状直流系统暂态量计算方法  

Calculation method of fault transient quantity of ring DC system based on fault model

作　　者：徐岩[1] 刘婧妍[1] 付媛[1] 王毅[1] Xu Yan;Liu Jingyan;Fu Yuan;Wang Yi(State Key Laboratory of New Energy and Electric Power Systems,North China Electric Power University,Baoding 071003,Hebei,China)

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,河北保定071003

出　　处：《电测与仪表》2018年第13期1-6,共6页Electrical Measurement & Instrumentation

基　　金：国家自然科学基金资助项目(51607070);中央高校基本科研业务费专项资金资助项目(2015MS93)

摘　　要：多端柔性直流系统线路上发生极间短路时,不同换流站共同作用,导致故障电流上升迅速,故障特性复杂,工程实际中要求在电容放电阶段将故障进行切除,更增加了求解的难度。针对此问题,首先提出将n端系统电容放电过程分解为n个单端电容单独作用过程,简化了计算量。然后,根据分解前后多端模型与单端模型的参数关系表达式计算出最终结果,并分析参数的变化对故障特性的影响。最后,利用MATLAB/Simulink软件搭建了3端环状直流系统的故障模型,验证了方法的可靠性,为保护方案的设计提出了建议。该方法为直流保护中整定值的计算提供了理论依据。When the pole-to-pole fault occurs in multi-terminal flexible DC system,all the converter station act together,resulting in the fault current increasing rapidly and the fault characteristics are very complex. It is required to remove the fault before the voltage zero crossing point,but also increased the difficulty of solving. A practical method is proposed to solve the current and voltage transient expression. Aiming at this problem,the n-terminal system capacitor discharge process is decomposed into n single-ended capacitor alone process,which simplifies the calculation process. Then,the influence of the parameter change on the fault characteristics is analyzed according to the parameters expression before and after decomposition. Finally,the fault model of 3-terminal ring DC system is built by MATLAB/Simulink software,which verifies the reliability of the method and provides theoretical basis for the protection setting value.

关 键 词：多端直流系统 故障模型 保护 电容放电阶段 

分 类 号：TM933[电气工程—电力电子与电力传动]