UHV输电暂态信号的动力学分析新方法

New Research Approach Using Dynamic Analysis for Ultra High Voltage(UHV)Transmission Transient Signal

特高压交流输电线路故障的正确识别与快速切除对于保障整个系统的安全、稳定和可靠运行具有重要意义。通过PSCAD-EMTDC仿真,在比较不同故障类型下故障相、非故障相最大过电流大小的基础上,本文从动力学角度分析了故障信号混沌特征的变化规律。利用Duffing混沌系统对于环境噪声具有较好的抗干扰性的特点,以检测到的故障信号作为该系统的摄动输入,得到了不同故障类型下的相轨迹图,再利用小波边缘检测技术提取到了各相图中的故障指纹信息。最后对某750kV输电线路的故障信号进行了识别,结果表明,该系统具有较好的故障识别能力,验证了该方法的正确性。

It is important to protect the entire power grid for security,stability and reliable operation through identifying fault correctly and removing it rapidly for UHV AC transmission line.By PSCAD-EMTDC simulation,on the basis of comparing maximum overcurrent of the fault phase and non-fault phase for different faults types,from view point of dynamics,this paper analyses the variation rule of chaotic characteristics for fault signals.Utilizing the better anti-interference characteristics of Duffing chaos system for environmental interference,phase trajectory diagrams under different fault types are obtained by using fault signals detected as the perturbation input of system,and then the finger mark fault information is extracted using wavelet edge detection technique for each phase diagram.Finally,different fault types are classified accurately by fault signals using Duffing chaos system for one 750kV transmission line.Results show that this detection method has preferable ability to identify faults,whose validity is verified.