The single phase grounding fault location is the focus which researchers pay attention to and study in power system. The accurate fault location can lighten the patrolling burden, and enhance the reliability of the po...The single phase grounding fault location is the focus which researchers pay attention to and study in power system. The accurate fault location can lighten the patrolling burden, and enhance the reliability of the power network. It adopts A/D which has high speed, and uses TMS320VC5402 DSP chip as the system core. This paper presented theory of operation based on traveling waves and achieved software and hardware in detail.展开更多
This paper introduced correlation method to locate transmission line fault.First it described the principle of transmission line fault location based on traveling waves.The principle of correlation analysis is introdu...This paper introduced correlation method to locate transmission line fault.First it described the principle of transmission line fault location based on traveling waves.The principle of correlation analysis is introduced,then the method using correlation analysis in fault location is given.Transmission line model is established with EMTP-ATP.Basing on the model,some kinds of fault are simulated.The feasibility of this algorithm is proved based on simulation results.By comparing with the classical wavelet analysis,this paper gave the advantages of this algorithm in two cases:noise influence suppression and accuracy of near distance fault location.Experiment is established to simulate transmission line grounding fault.The experiment result showed the correlation algorithm's validity.All the analysis result indicated that the correlation algorithm have a high precision.展开更多
针对全并联自耦变压器(auto-transformer,AT)牵引网故障点反射波波头微弱难辨识,且线路并联结构导致故障行波折反射复杂而造成定位困难的问题,提出基于变分模态分解(variational mode decomposition,VMD)和改进能量算子的牵引网故障行...针对全并联自耦变压器(auto-transformer,AT)牵引网故障点反射波波头微弱难辨识,且线路并联结构导致故障行波折反射复杂而造成定位困难的问题,提出基于变分模态分解(variational mode decomposition,VMD)和改进能量算子的牵引网故障行波单端定位方法。首先,深入分析牵引网故障行波的传输特性,研究全并联结构对行波折反射的影响,确定不同故障类型和潮流特征,以此为依据提取故障特征量,将波头辨识转化为能量突变值提取;随后,利用VMD去噪提取电压行波真实分量,再针对第二反射波波头微弱难标定问题,在滑动时间窗口(sliding time window,STW)下,结合对称差分能量算子(symmetrical differencing energy operator,SDEO)构造故障信号的二次瞬时能量谱,效果良好。仿真结果表明:所提方法抗过渡电阻能力强,能够反应不同工况下故障牵引网电磁能量的变化,具有较高的定位精度。展开更多
基于晶闸管换流器的特高压直流输电系统(ultra-high voltage direct current based on line commutated converter,LCC-UHVDC)的故障定位算法对智能电网的安全稳定运行起着重要作用。针对长距离特高压直流输电系统故障测距方法精准度低...基于晶闸管换流器的特高压直流输电系统(ultra-high voltage direct current based on line commutated converter,LCC-UHVDC)的故障定位算法对智能电网的安全稳定运行起着重要作用。针对长距离特高压直流输电系统故障测距方法精准度低、快速性差的问题,提出了一种基于变分模态分解法(variational mode decomposition,VMD)和Teager能量算子(Teager energy operator,TEO)的双端行波故障测距方法。首先,研究了LCC-UHVDC线路故障电压行波的传播特性。利用零模电压随线路传播衰减明显的特征,通过VMD算法提取采样点处零模电压行波的时频特性。针对VMD参数选择不当导致的模态混叠问题,利用K-L散度(Kullback-Leibler divergence)对提取的模态指标进行优化。然后采用TEO对分解后信号进行瞬时能量谱提取,精确标定波头到达时间,最后采用双端迭代测距法迭代求解故障距离。在PSCAD/EMTDC搭建±800 kV LCC-UHVDC仿真模型进行验证。结果表明,所提方法在不同故障位置、过渡电阻和故障类型下具有较强的鲁棒性。展开更多
直流输电线路故障行波波速不确定、波头提取困难以及噪声干扰等因素制约了直流电网中故障测距技术的应用。为了降低上述因素对定位准确性的影响,提出一种基于局部特征有理样条插值均值分解(LMD based on characteristic rational spline...直流输电线路故障行波波速不确定、波头提取困难以及噪声干扰等因素制约了直流电网中故障测距技术的应用。为了降低上述因素对定位准确性的影响,提出一种基于局部特征有理样条插值均值分解(LMD based on characteristic rational spline,CRS-LMD)和奇异值分解(singular value decomposition,SVD)的故障测距方法。首先,利用特征尺度选取最优极点系数,结合有理样条插值调节拟合曲线的松紧程度,实现对故障电压行波的局部均值分解。其次,采用奇异值分解对故障行波波头进行准确提取。最后,在PSCAD/EMTDC中搭建了张北±500 kV柔性直流电网的仿真模型,模拟各种故障情况并输出故障数据,利用Matlab对故障数据进行处理并验证定位算法。最后,仿真结果表明,所提故障测距算法在不同故障距离和故障类型下均能实现故障测距,且在叠加噪声和过渡电阻的情况下也能保障较高的精确性。展开更多
文摘The single phase grounding fault location is the focus which researchers pay attention to and study in power system. The accurate fault location can lighten the patrolling burden, and enhance the reliability of the power network. It adopts A/D which has high speed, and uses TMS320VC5402 DSP chip as the system core. This paper presented theory of operation based on traveling waves and achieved software and hardware in detail.
基金Project Supported by Chongqing Science and Technology Committee(2005AA600)
文摘This paper introduced correlation method to locate transmission line fault.First it described the principle of transmission line fault location based on traveling waves.The principle of correlation analysis is introduced,then the method using correlation analysis in fault location is given.Transmission line model is established with EMTP-ATP.Basing on the model,some kinds of fault are simulated.The feasibility of this algorithm is proved based on simulation results.By comparing with the classical wavelet analysis,this paper gave the advantages of this algorithm in two cases:noise influence suppression and accuracy of near distance fault location.Experiment is established to simulate transmission line grounding fault.The experiment result showed the correlation algorithm's validity.All the analysis result indicated that the correlation algorithm have a high precision.
文摘针对全并联自耦变压器(auto-transformer,AT)牵引网故障点反射波波头微弱难辨识,且线路并联结构导致故障行波折反射复杂而造成定位困难的问题,提出基于变分模态分解(variational mode decomposition,VMD)和改进能量算子的牵引网故障行波单端定位方法。首先,深入分析牵引网故障行波的传输特性,研究全并联结构对行波折反射的影响,确定不同故障类型和潮流特征,以此为依据提取故障特征量,将波头辨识转化为能量突变值提取;随后,利用VMD去噪提取电压行波真实分量,再针对第二反射波波头微弱难标定问题,在滑动时间窗口(sliding time window,STW)下,结合对称差分能量算子(symmetrical differencing energy operator,SDEO)构造故障信号的二次瞬时能量谱,效果良好。仿真结果表明:所提方法抗过渡电阻能力强,能够反应不同工况下故障牵引网电磁能量的变化,具有较高的定位精度。
文摘基于晶闸管换流器的特高压直流输电系统(ultra-high voltage direct current based on line commutated converter,LCC-UHVDC)的故障定位算法对智能电网的安全稳定运行起着重要作用。针对长距离特高压直流输电系统故障测距方法精准度低、快速性差的问题,提出了一种基于变分模态分解法(variational mode decomposition,VMD)和Teager能量算子(Teager energy operator,TEO)的双端行波故障测距方法。首先,研究了LCC-UHVDC线路故障电压行波的传播特性。利用零模电压随线路传播衰减明显的特征,通过VMD算法提取采样点处零模电压行波的时频特性。针对VMD参数选择不当导致的模态混叠问题,利用K-L散度(Kullback-Leibler divergence)对提取的模态指标进行优化。然后采用TEO对分解后信号进行瞬时能量谱提取,精确标定波头到达时间,最后采用双端迭代测距法迭代求解故障距离。在PSCAD/EMTDC搭建±800 kV LCC-UHVDC仿真模型进行验证。结果表明,所提方法在不同故障位置、过渡电阻和故障类型下具有较强的鲁棒性。
文摘直流输电线路故障行波波速不确定、波头提取困难以及噪声干扰等因素制约了直流电网中故障测距技术的应用。为了降低上述因素对定位准确性的影响,提出一种基于局部特征有理样条插值均值分解(LMD based on characteristic rational spline,CRS-LMD)和奇异值分解(singular value decomposition,SVD)的故障测距方法。首先,利用特征尺度选取最优极点系数,结合有理样条插值调节拟合曲线的松紧程度,实现对故障电压行波的局部均值分解。其次,采用奇异值分解对故障行波波头进行准确提取。最后,在PSCAD/EMTDC中搭建了张北±500 kV柔性直流电网的仿真模型,模拟各种故障情况并输出故障数据,利用Matlab对故障数据进行处理并验证定位算法。最后,仿真结果表明,所提故障测距算法在不同故障距离和故障类型下均能实现故障测距,且在叠加噪声和过渡电阻的情况下也能保障较高的精确性。
