摘要
针对乒乓式一点接地保护无法解决励磁电压变化对保护精度和灵敏度的影响问题,提出了在励磁回路的双端注入一个直流电压,并将开关切换回路接在该电压两端的改进方案,给出了该方案的原理和动作判据,并对接地电阻的计算方法进行分析。仿真实验结果表明改进方案能满足实际运行需要的精度和灵敏度。
Current ping-pong type of field winding ground protections cannot detect the accuracy and sensitivity of winding affected by voltage change.To remedy this defect,the paper uses an improving scheme for ping-pong type field winding ground protection,that is,a DC voltage is injected into field winding and a switching-over circuit is connected in parallel with the injected voltage.The principle of this improving scheme and the criterion for protection action are given;and several problems such as the calculation method of grounding resistance are analyzed.Simulation results show that the accuracy and sensitivity of the improving scheme can meet the requirement of practical operation.
出处
《南方电网技术》
2011年第2期76-80,共5页
Southern Power System Technology
关键词
发电机
励磁回路接地
保护
灵敏度
generator
field winding ground
protection
sensitivity
