The autotransformer(AT)neutral current ratio method is widely used for fault location in the AT traction power network.With the development of high-speed electrified railways,a large number of data show that the relat...The autotransformer(AT)neutral current ratio method is widely used for fault location in the AT traction power network.With the development of high-speed electrified railways,a large number of data show that the relation between the AT neutral current ratio and the distance from the beginning of the fault AT section to the fault point(Q-L relation)is mostly nonlinear.Therefore,the linear Q-L relation in the traditional fault location method always leads to large errors.To solve this problem,a large number of load-related current data that can be used to describe the Q-L relation are obtained through the load test of the electric multiple unit(EMU).Thus,an improved fault location method based on the back propagation(BP)neural network is proposed in this paper.On this basis,a comparison between the improved method and the traditional method shows that the maximum absolute error and the average absolute error of the improved method are 0.651 km and 0.334 km lower than those of the traditional method,respectively,which demonstrates that the improved method can effectively eliminate the influence of nonlinear factors and greatly improve the accuracy of fault location for the AT traction power network.Finally,combined with a shortcircuit test,the accuracy of the improved method is verified.展开更多
The features of three modes of AT-fed traction power networks (TPNs) have been briefly described in the existing literature, which is not adequate yet. In this paper, these three modes of TPNs are compared mainly on T...The features of three modes of AT-fed traction power networks (TPNs) have been briefly described in the existing literature, which is not adequate yet. In this paper, these three modes of TPNs are compared mainly on TPN capacity, transformer capacity, rail potential and voltage level, etc., and conclusions are drawn.展开更多
随着我国风电装机容量与高速铁路运营里程不断增长,部分地区出现风电场与电气化铁路共同接入电网公共连接点(point of common coupling,PCC)的情况,将会引发一系列谐波不稳定问题。针对此类问题,对风电场与多车接入牵引网耦合系统进行...随着我国风电装机容量与高速铁路运营里程不断增长,部分地区出现风电场与电气化铁路共同接入电网公共连接点(point of common coupling,PCC)的情况,将会引发一系列谐波不稳定问题。针对此类问题,对风电场与多车接入牵引网耦合系统进行稳定性研究(为便于阐述,将牵引变电所、接触网与列车视为一个整体,称为牵引供电系统),建立了电网-牵引供电系统-风电场耦合系统导纳模型,并结合阻抗扫频验证了模型的准确性。接着分析了传输线路长度对电网-牵引供电系统-风电场耦合系统谐波稳定性的影响,并基于风电场、牵引供电系统的导纳Bode图进一步揭示了风电场和牵引供电系统交互影响的产生机理,并探究了耦合系统临界稳定时机车数量与风机数量比例条件。最后,基于Matlab/Simulink仿真和Starsim/HIL硬件在环仿真平台,验证了所建模型对电网-牵引供电系统-风电场耦合系统谐波不稳定现象研究的有效性和正确性。展开更多
在交-直-交电力机车和交-直电力机车混跑线路的牵引供电系统中,存在丰富的宽频域谐波电流,且易产生车网谐振问题。文章首先采用谐波阻抗分析法建立了牵引网谐波阻抗电路模型,推导了牵引网谐振阻抗与谐波频率及供电臂长度的函数关系,分...在交-直-交电力机车和交-直电力机车混跑线路的牵引供电系统中,存在丰富的宽频域谐波电流,且易产生车网谐振问题。文章首先采用谐波阻抗分析法建立了牵引网谐波阻抗电路模型,推导了牵引网谐振阻抗与谐波频率及供电臂长度的函数关系,分析车网谐振产生机理和谐振特性,给出了车网谐振治理方式及装置安装位置的选择;然后,针对目前牵引网的宽频域谐波,提出一种地面加装有源电力滤波器(active power filter,APF)和无源高通滤波器(high pass filter,HPF)的综合治理方法,并给出“APF+HPF”装置的工程设计方法;最后,结合国内某铁路牵引网案例进行仿真验证。仿真结果显示,采用该方法后谐波电流总畸变率由75.29%下降到1.58%(“APF+二阶HPF”滤波器)和2.55%(“APF+阻波HPF”滤波器),证明该方法对宽频域谐波具有良好的治理效果,能有效抑制车网谐振现象并消除其危害,保障了牵引供电系统的安全运行。展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFB2601500)the Natural Science Foundation of Sichuan Province(No.2022NSFSC0405)。
文摘The autotransformer(AT)neutral current ratio method is widely used for fault location in the AT traction power network.With the development of high-speed electrified railways,a large number of data show that the relation between the AT neutral current ratio and the distance from the beginning of the fault AT section to the fault point(Q-L relation)is mostly nonlinear.Therefore,the linear Q-L relation in the traditional fault location method always leads to large errors.To solve this problem,a large number of load-related current data that can be used to describe the Q-L relation are obtained through the load test of the electric multiple unit(EMU).Thus,an improved fault location method based on the back propagation(BP)neural network is proposed in this paper.On this basis,a comparison between the improved method and the traditional method shows that the maximum absolute error and the average absolute error of the improved method are 0.651 km and 0.334 km lower than those of the traditional method,respectively,which demonstrates that the improved method can effectively eliminate the influence of nonlinear factors and greatly improve the accuracy of fault location for the AT traction power network.Finally,combined with a shortcircuit test,the accuracy of the improved method is verified.
文摘The features of three modes of AT-fed traction power networks (TPNs) have been briefly described in the existing literature, which is not adequate yet. In this paper, these three modes of TPNs are compared mainly on TPN capacity, transformer capacity, rail potential and voltage level, etc., and conclusions are drawn.
文摘随着我国风电装机容量与高速铁路运营里程不断增长,部分地区出现风电场与电气化铁路共同接入电网公共连接点(point of common coupling,PCC)的情况,将会引发一系列谐波不稳定问题。针对此类问题,对风电场与多车接入牵引网耦合系统进行稳定性研究(为便于阐述,将牵引变电所、接触网与列车视为一个整体,称为牵引供电系统),建立了电网-牵引供电系统-风电场耦合系统导纳模型,并结合阻抗扫频验证了模型的准确性。接着分析了传输线路长度对电网-牵引供电系统-风电场耦合系统谐波稳定性的影响,并基于风电场、牵引供电系统的导纳Bode图进一步揭示了风电场和牵引供电系统交互影响的产生机理,并探究了耦合系统临界稳定时机车数量与风机数量比例条件。最后,基于Matlab/Simulink仿真和Starsim/HIL硬件在环仿真平台,验证了所建模型对电网-牵引供电系统-风电场耦合系统谐波不稳定现象研究的有效性和正确性。
文摘在交-直-交电力机车和交-直电力机车混跑线路的牵引供电系统中,存在丰富的宽频域谐波电流,且易产生车网谐振问题。文章首先采用谐波阻抗分析法建立了牵引网谐波阻抗电路模型,推导了牵引网谐振阻抗与谐波频率及供电臂长度的函数关系,分析车网谐振产生机理和谐振特性,给出了车网谐振治理方式及装置安装位置的选择;然后,针对目前牵引网的宽频域谐波,提出一种地面加装有源电力滤波器(active power filter,APF)和无源高通滤波器(high pass filter,HPF)的综合治理方法,并给出“APF+HPF”装置的工程设计方法;最后,结合国内某铁路牵引网案例进行仿真验证。仿真结果显示,采用该方法后谐波电流总畸变率由75.29%下降到1.58%(“APF+二阶HPF”滤波器)和2.55%(“APF+阻波HPF”滤波器),证明该方法对宽频域谐波具有良好的治理效果,能有效抑制车网谐振现象并消除其危害,保障了牵引供电系统的安全运行。
