摘要
对转子电压采用电阻分压方式,将分压后的电压引入保护装置,参与转子接地运算。针对目前常见的乒乓式与低频电源注入式2种接地保护,从接地电阻及接地位置2个方面对保护测量的影响进行理论分析,并提出相应的改进方案。以三峡ALSTOM机组为例,在PSCAD/EMTDC建立仿真模型,仿真数据结果表明,采用电阻分压式转子接地保护能准确计算接地电阻阻值及接地位置,避免较高电压直接接入保护屏,同时利用对不同抽取电阻的切换,能正确定位接地点是在励磁回路上还是在测量回路引线电缆上。
The resistor divider mode is used for the rotor voltage, which is introduced to protective devices to take part in the rotor earth fault protection calculation. Based on the current common modes of earth fault protection, namely, the Ping-Pong type and voltage injection type, a theoretical analysis of the impact on protective measurement is made from two aspects, the grounding resistance and grounding location, with the corresponding solutions put forward. The ALSTOM units of the Three Gorges are taken as an example and the simulation model is built in PSCAD/EMTDC. Simulation results show that the grounding resistance value and location can be accurately calculated using rotor earth fault protection in the resistor divider mode, avoiding high voltage getting switched into the protection screen directly. Meanwhile, by changing different extraction resistors, it is possible to know whether the grounding point located on the leader cable in the excitation circuit or measuring circuit.
出处
《电力系统自动化》
EI
CSCD
北大核心
2013年第22期90-95,共6页
Automation of Electric Power Systems
关键词
转子接地
电阻分压
乒乓式
注入式
测量电阻
接地位置
rotor earth fault
resistor divider
Ping-Pong type
injection type
measuring resistor
grounding location
