【摘要】 通过对输电线路故障暂态电流的理论分析 ,发现区内、外故障时暂态电流由于线路阻波器、结合设备以及杂散电容的影响有所不同 ,主要表现在两个方面 ,一是每个突变点 (行波到达时刻 )的波形变化的陡变不同 ,二是在一个时间段内包含的高频分量不同。利用小波变换提取和放大两者的差异可以构成输电线路的保护判据。仿真结果表明 ,利用小波变换提出的保护算法足以放大和提取这种差异而构成正确的保护判据。更多还原

【Abstract】 The paper proposes a new principle of line protection based on fault transient current signals by study of transmission line electromagnetic transients.The result of transient current signal analysis shows that there exist differences between internal and external faults mainly because of the line traps and bus bar capacitance.Using wavelet transform can extract and amplify the difference to construct non unit protection discrimination.The EMTP simulations show that the discriminate is correct.更多还原