电容换相换流器在预防高压直流换相失败上的特性研究  

Characteristics of capacitor commutated converter in the prevention of HVDC in commutation failure

作　　者：李思思[1] 贺兴容[2] 明志强[2] 王渝红[1] 李兴源[1] 何鹏飞[1] 

机构地区：[1]四川大学电气信息学院,四川成都610065 [2]四川省电力公司超(特)高压运行检修公司,四川成都610041

出　　处：《电力系统保护与控制》2011年第18期88-92,133,共6页Power System Protection and Control

摘　　要：换相失败是高压直流输电最常见的故障之一,严重时会导致极停运给电网带来更大危害。一种人工换相技术—电容换相换流器(CCC),借助于换相电容上的电压能有效地减少换相失败发生概率。从CCC的数学机理出发,将CCC运用到高压直流,研究其在预防换相失败上的特性。以德宝直流枯小方式为模型,在PSCAD/EMTDC中采用优化仿真的方法通过计算换相失败临界阻抗的大小,反映CCC在预防高压直流换相失败上的特性。仿真结果表明,CCC的应用能够有效预防高压直流的换相失败。As commutation failure is one of the most frequent faults in HVDC, it may aggravate the damage of network when bipolar unplanned outage. The capacitor commutated converter（CCC） is a method of artificial commutation. The voltages on capacitors aid in the commutation process and effectually reduce the probability of commutation failure. The mathematical model of CCC is presented firstly and its commutated characteristics are studied in the prevention of HVDC in commutation failure. Taking De-Bao DC dry small mode as a model, the commutation critical impedances are calculated by using optimal simulation module in PSCAD/EMTDC. According to the critical impedances, the characteristics of CCC＇s commutation-improving under grounding faults are tested. Simulation results show that the application of CCC in HVDC can effectively prevent the converter from commutation failure.

关 键 词：人工换相 电容换相换流器 高压直流 换相失败 临界阻抗 

分 类 号：TM721.1[电气工程—电力系统及自动化]