摘要
针对直流配网中换流器交流出口处的单相接地故障,对故障下直流侧正负极电容电压的响应进行了推导,并给出了故障下单个换流站的零序等效电路。对故障消除后直流正负极电压的恢复过程进行了分析。分别从在故障下消除直流正负极电容电压的工频共模波动和在故障消除后直流正负极电压的快速恢复2个角度对电容中点接地电阻的取值进行了讨论。提出了电容中点接地电阻的取值依据。最后通过PSCAD/EMTDC仿真软件进行了直流配网系统故障仿真,对结论进行了验证。
Response of DC capacitor voltage of the voltage source convertor in DC distribution network under asymmetry fault at its internal AC bus is derived. And the zero-sequence equivalent circuit of the converter station under AC side asymmetric fault is obtained. The voltage restoration process of DC side after fault is analyzed. Value of the grounding resistance of DC capacitor midpoint is discussed, based on both the following points, to eliminate the fundamental common-mode oscillations of the DC positive and negative capacitors during fault and to achieve fast recovery of the DC voltage after fault. Value selection rules of the grounding resistance of DC capacitor midpoint are proposed. The conclusion is verified by the results of simulations by PSCAD/EMTDC.
出处
《电网技术》
EI
CSCD
北大核心
2014年第10期2665-2670,共6页
Power System Technology
基金
国家863高技术基金项目(2013AA050104)~~
关键词
直流配网
电压源换流器
接地方式
不对称故障
电容电压平衡
零序分量
DC distribution system
voltage sourceconverter
grounding method
unbalanced fault
capacitorvoltage balance
zero sequence components