基于MATLAB的电快速瞬变脉冲群形成机理及防护措施研究

Study on the Forming Mechanism and Safeguard Procedures of EFT/B

根据开关操作时形成电快速瞬变脉冲群的过程,在MATLAB中建立了隔离开关电弧重燃和熄灭的模型,仿真电力系统一次回路中隔离开关切感性负载(空载变压器)时引起的电快速瞬变脉冲群,得到相关电压波形与结果,并采取MOV(金属氧化物避雷器)保护,RC保护,相控开关技术抑制一次回路中的电快速瞬变脉冲群,根据其特点提出综合配合措施,通过仿真验证了采取措施的正确性。通过该工作,介绍利用MATLAB建立瞬态干扰模型的方法,利用MATLAB的易扩展性,为电力系统暂态干扰抑制建模提供新思路。

Electrical Fast Transient Burst（EFT/B） has characteristic such as short rise time and duration,high amplitude and repeat frequency.It interfere the microcomputer protection system in the transformer station.This is a difficult problem and is hard to conquer.Based on the Mechanism of EFT/B when the no-load transformer switching-off,build the extinguish and restrike model of the isolating switch voltaic arc and got the according voltage waves.Because most integrating circuit for resisting transient disturbance have no-effect level of the pulse train,the safeguard procedures are adopted such as metal-oxide varistor,the RC snubber,phase-controlled switch to test the ability of resisting EFT/B in the primary loop.Based on the analysis,a comprehensive method of resisting EFT/B which overcomes the above drawback is proposed.The model is equipped with easy expansibility of MATLAB and the whole work provides new strategies building transient model.