一种考虑RSC和GSC的双馈风机短路电流实用计算方法  

A practical calculation method for short-circuit current of DFIG considering RSC and GSC

作　　者：靳现林 蔡晓宇[2] 刘其辉[2] 刘自发[2] JIN Xianlin;CAI Xiaoyu;LIU Qihui;LIU Zifa(Guohua Energy Investment Co.,Ltd.,Beijing 100007,China;North China Electric Power University,Beijing 102206,China)

机构地区：[1]国华能源投资有限公司,北京100007 [2]华北电力大学,北京102206

出　　处：《电力系统保护与控制》2019年第24期23-30,共8页Power System Protection and Control

基　　金：国家重点研发计划项目资助“大容量风电机组电网友好型控制技术”(2018YFB0904000);国家电网公司科技项目资助(SGJB0000TKJS1801242);神华集团科技项目资助“双馈机组异常工况仿真及故障分析”(SHNY(2018)0049)~~

摘　　要：由于双馈风机(DFIG)的短路电流特性与传统电机不同,使其保护整定变得困难。针对电网对称故障下双馈风机短路电流,提出一种同时考虑机侧变流器(RSC)和网侧变流器(GSC)故障期间特性的双馈风机短路电流实用计算方法。在电网电压轻度跌落时,考虑RSC和GSC对风机暂态特性的影响。在电网电压深度跌落时综合考虑RSC、GSC和撬棒保护(Crowbar)的影响,把风机短路电流视为定子短路电流和变流器GSC输出电流两部分之和。建立双馈风机短路电流计算数学模型,并在数学模型中体现Crowbar动作的延时性。计算过程以Crowbar动作时刻为时间分界点,获得短路电流时域表达式,计算短路电流的最大值和有效值。在PSCAD中进行仿真验证,验证所用方法的准确性和有效性。Since the Short Circuit(SC) characteristics of DFIG are different from traditional generators, the protection setting of DFIG becomes difficult. A practical calculation method for SC current of DFIG under symmetrical fault of power grid is proposed, considering both the characteristics of the Rotor Side Converter(RSC) and Grid Side Converter(GSC) during fault. The influence of RSC and GSC on the transient characteristics is considered under a slight voltage dip, and the influence of RSC, GSC and Crowbar protection is considered under a severe voltage dip. The SC current is regarded as the sum of the stator SC current and the GSC output current. The mathematical model of SC current calculation is established, and the delay of Crowbar action is reflected in the modeling. The calculation process is segmented by Crowbar action time. The time domain expression of SC current is obtained and the maximum and valid value of SC current is computed. The simulation analysis is achieved in PSCAD to verify the accuracy and validity of the method.

关 键 词：双馈风力发电机组 电压跌落 短路电流 撬棒保护 低电压穿越 

分 类 号：TM315[电气工程—电机] TM713