摘要
励磁系统是发电系统的重要组成部分,应针对其可能的故障形式装设必要的保护。文章首先利用电磁暂态程序(EMTP)建立了静止励磁系统的仿真模型,并在此基础上研究了励磁变压器低压侧单相接地和整流主回路异常时保护测量回路的波形特征。仿真结果表明,当出现上述故障时,转子接地保护测量的取样电压及失磁保护测量的励磁电压都会出现大量的非特征谐波,这一特点可用来改进发变组保护的动作特性。
Excitation system is an important component of power generation system and necessary protection devices should be configured according to its probable fault types. Here, firstly a simulation model of static excitation system is established by use of electromagnetic transient program (EMTP), on this basis the features of waveform outputs in measurement circuits of protection relays are researched when single phase grounding fault at low voltage side of excitation transformer and the abnormality in main circuit of rectifying bridge occur. Simulation results show that when above mentioned faults appear, a lot of non-characteristic harmonics will appear in the sampling voltage measured by rotor winding earth fault protection and the excitation voltage measured by loss-of-excitation protection, therefore these phenomena can be used to improve the action characteristics of the protections for generator-transformer units.
出处
《电网技术》
EI
CSCD
北大核心
2005年第12期66-71,共6页
Power System Technology
