弧光接地过电压故障逻辑保护模型研究

Research on the Logic Fault Protection Model of Arc-grounding Overvoltage

现代城镇全电缆配电网中电容电流很大,极易引起弧光接地过电压,建立准确的电弧接地故障模型是研究弧光接地过电压故障保护相关问题的重要理论基础。鉴于此,作者在研究分析有关电弧接地故障模型理论、电弧优化控制模型、弧道电阻的非线性变化分析方法的基础上,建立了一种以故障相电压和故障接地点电流作为燃弧和熄弧的控制条件的新型逻辑电弧优化综合控制模型,解决了以往电弧模型控制不精确、电弧电阻为定值的缺陷。利用MATLAB进行了对比验证,仿真结果表明本模型能够准确的反应出实际弧光接地过电压特性,为深入研究弧光接地过电压故障保护提供了新方法。

The arc-grounding overvoltage can be produced very easily because of strong capacitive current in the cable distribution network of modern urban areas. Building an accurate model is important to the theory development of arc-grounding overvoltage. Hence the theory of existing arc-grounding fault model and the arc optimization control model with the methods of arc resistance of nonlinear are analyzed in this paper. A new logic optimization model using the fault phase voltage and ground fault current as arcing and arc extinguishing control condition was developed. It solves the problem ofinaccuracy in arc model control and the problem of fixed arc resistance value. The simulation results of MATLAB proved the new model can immediately respond to the actual arc grounding overvoltage,thus offering a new model for the fault protection of arc-grounding overvoltage.