35kV及以下变电站系统接地选线方案的研究

Research on Grounding Line Selection Scheme for 35 kV and Below Substation Systems

对于小电流接地系统的35 kV及以下的变电站系统,由于综合自动化的应用,其接地选线可以采用微机保护装置及监控系统实现。提出了利用微机保护装置实现小电流接地选线的检测原理,给出了以Modbus为总线的变电站监控系统的选线方案。应用小波变换方式从暂态故障电流中提取故障特征,可以提高故障选线的精度和可靠性。可以优化变电站的结构,减少二次电缆,节省空间,提高接地选线的正确性。

For 35kV and below substation system of small current grounding systems,due to the application of integrated automation,the grounding line selection can be realized by the microcomputer protection device and monitoring system. This paper proposes the detection principle of small current grounding line selection realized through the microcomputer protection device,and gives the line selection scheme of the substation monitoring system using Modbus. By using wavelet transform to extract fault characteristics from transient fault current. We can improve the accuracy and reliability of fault line selection. This scheme can optimize the substation structure,reduce secondary cables,save space and improve the correctness of grounding line selection.