静止励磁系统保护配置方案

结合现有的机组保护配置方案和静止励磁系统的基本组成,分析了励磁系统保护方案的不足。发生在励磁变低压侧的单相接地故障无法通过现有的保护方案提供有效保护,但却可能引起转子接地保护的误动。可控整流桥的断臂、触发脉冲丢失等故障直接引起励磁电压大小和波形的变化,可能引起基于励磁电压原理的失磁保护的不正确动作。因此,建议深入研究励磁系统各种故障对现有保护原理的影响,并采取措施提高现有保护方案的性能。

Protection Configuration Scheme of Static Excitation System

Based on the available protection configuration schemes of generator-transformer unit and basic composition of static excitation system, this paper analyzes the disadvantages of protection configuration schemes of excitation system. It is concluded that the single phase grounding faults occurred in low voltage sides of excitation transformer can't be effectively protected by existing protection scheme and may cause improper operation of rotor grounding relay. Arms breaking and trigger pulse losing of controlled rectifier bridge can directly lead to the variation of amplitude and waveform of excitation voltage, which maybe result in improper operation of loss-of-excitation protection based on excitation voltage. Therefore, this paper suggests that the influence of excitation system faults on existing protection principles must be carefully studied and some measures must be taken to improve the performance of existing protection schemes.