CN103245876B

CN103245876B - Voltage drop real part characteristic is utilized to realize circuit inter-phase fault single-end ranging

Info

Publication number: CN103245876B
Application number: CN201310129414.XA
Authority: CN
Inventors: 曾惠敏; 林富洪
Original assignee: State Grid Corp of China SGCC; State Grid Fujian Electric Power Co Ltd; Maintenance Branch of State Grid Fujian Electric Power Co Ltd; Putian Power Supply Co of State Grid Fujian Electric Power Co Ltd
Current assignee: State Grid Corp of China SGCC; State Grid Fujian Electric Power Co Ltd; Maintenance Branch of State Grid Fujian Electric Power Co Ltd; Putian Power Supply Co of State Grid Fujian Electric Power Co Ltd
Priority date: 2013-04-15
Filing date: 2013-04-15
Publication date: 2015-08-26
Anticipated expiration: 2033-04-15
Also published as: CN103245876A

Abstract

The invention discloses a single-end distance measuring method for phase-to-phase faults of lines by utilizing the characteristics of the real part of voltage drop. The method of the present invention uses the negative sequence voltage between fault phases and the positive sequence impedance of the transmission line per unit length to calculate the voltage phase angle of the short circuit fault point between phases, and then calculates the additional fault distance caused by the transition resistance, and uses the ratio of the fault phase voltage to the voltage drop of the transmission line per unit length Subtract the additional fault distance caused by the transition resistance from the real part of , and get the fault distance from the transmission line protection installation to the phase-to-phase short-circuit fault point. The method of the present invention overcomes the problem of the influence of transition resistance and load current on the accuracy of single-ended fault distance measurement, and the method of the present invention has very high distance measurement accuracy when there is a high-resistance short-circuit fault between phases of the transmission line, the principle of distance measurement is simple, and the program is easy to implement, and There is no need to use search algorithms to directly calculate the fault distance, and the ranging speed is fast and the real-time performance is strong.

Description

Using the characteristics of the real part of the voltage drop to realize the single-end distance measurement method of the phase-to-phase fault of the line

技术领域technical field

本发明涉及电力系统继电保护技术领域，具体地说是涉及一种利用电压降实部特性实现线路相间故障单端测距方法。The invention relates to the technical field of electric power system relay protection, in particular to a single-end distance measuring method for phase-to-phase faults of lines by using the characteristics of the real part of voltage drop.

背景技术Background technique

输电线路单端故障测距方法仅利用输电线路一端电气量进行故障定位，无须通讯和数据同步设备，运行费用低且算法稳定，在输电线路中获得广泛应用。输电线路单端故障测距方法主要分为行波法和阻抗法。行波法利用故障暂态行波的传送性质进行单端故障测距，精度高，不受运行方式、过度电阻等影响，但对采样率要求很高，需要专门的录波装置，应用成本高。阻抗法利用故障后的电压、电流量计算故障回路阻抗，根据线路长度与阻抗成正比的特性进行单端故障测距，简单可靠，但故障测距精度受到过渡电阻和负荷电流等因素影响严重，尤其当过渡电阻较大时，因过渡电阻引起的附加故障距离的影响，故障距离测量结果会严重偏离真实故障距离，甚至出现故障测距失败。The single-end fault location method of transmission lines only uses the electrical quantity at one end of the transmission line for fault location, does not require communication and data synchronization equipment, has low operating costs and stable algorithms, and has been widely used in transmission lines. Single-ended fault location methods for transmission lines are mainly divided into traveling wave method and impedance method. The traveling wave method utilizes the transmission properties of fault transient traveling waves to perform single-ended fault location. It has high precision and is not affected by the operation mode and excessive resistance. However, it requires a high sampling rate, requires a special wave recording device, and has high application costs. . The impedance method uses the voltage and current after the fault to calculate the fault loop impedance, and performs single-ended fault location based on the characteristic that the line length is proportional to the impedance. It is simple and reliable, but the fault location accuracy is seriously affected by factors such as transition resistance and load current. Especially when the transition resistance is large, due to the influence of the additional fault distance caused by the transition resistance, the measurement result of the fault distance will seriously deviate from the real fault distance, and even failure of fault distance measurement may occur.

发明内容Contents of the invention

本发明的目的在于克服已有技术存在的不足，提供一种抗附加故障距离影响、能精确测量故障距离的利用电压降实部特性实现线路相间故障单端测距方法。The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a single-ended distance measurement method for phase-to-phase faults of lines that is resistant to the influence of additional fault distances and can accurately measure fault distances by utilizing the characteristics of the real part of voltage drop.

为完成上述目的，本发明采用如下技术方案：For accomplishing above-mentioned object, the present invention adopts following technical scheme:

(1)保护装置对输电线路保护安装处的电压互感器PT的电压波形和电流互感器CT的电流波形进行采样得到电压、电流瞬时值，并对其采样得到的电压、电流瞬时值利用傅里叶算法计算输电线路保护安装处的故障相间电压故障相间电流和故障相间负序电压其中，φφ＝AB、BC、CA相；(1) The protection device samples the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT at the installation place of the transmission line protection to obtain the instantaneous value of the voltage and current, and uses Fourier to obtain the instantaneous value of the voltage and current obtained by sampling Leaf Algorithm Calculation of Fault Phase-to-Phase Voltage at Transmission Line Protection Installation Fault phase current and the negative sequence voltage between the faulted phases Among them, φφ=AB, BC, CA phase;

(2)保护装置利用输电线路保护安装处的故障相间电压故障相间电流和故障相间负序电压计算因过渡电阻引起的附加故障距离Δx：(2) The protection device uses the transmission line to protect the fault phase-to-phase voltage at the installation place Fault phase current and the negative sequence voltage between the faulted phases Calculate the additional fault distance Δx due to transition resistance:

$Δx Δx = = - - \frac{Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]] - - Im Im [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]]}{Im Im [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]] - - Re Re [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]]} Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ} {z z}_{11}}]]$

其中，z₁为单位长度输电线路正序阻抗；为的虚部；为的实部；为的实部；为的实部；为的虚部；Re[z₁]为z₁的实部；Im[z₁]为z₁的虚部；Among them, z ₁ is the positive sequence impedance of the transmission line per unit length; for the imaginary part of for the real part of for the real part of for the real part of for The imaginary part of; Re[z ₁ ] is the real part of z ₁ ; Im[z ₁ ] is the imaginary part of z ₁ ;

(3)保护装置利用减去附加故障距离Δx得到输电线路保护安装处到相间短路故障点的故障距离x：(3) Protection device utilization Subtract the additional fault distance Δx to obtain the fault distance x from the transmission line protection installation to the phase-to-phase short-circuit fault point:

$x x = = Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] + + \frac{Re Re [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ}}{{\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]] - - Im Im [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]]}{Im Im [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]] - - Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]]} Re Re [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ} {z z}_{11}}]]$

其中，为的实部。in, for the real part of .

本发明与现有技术相比较，具有以下积极成果：Compared with the prior art, the present invention has the following positive results:

本发明方法利用故障相间负序电压与单位长度输电线路正序阻抗计算相间短路故障点电压相角，进而计算因过渡电阻引起的附加故障距离，利用故障相间电压与单位长度输电线路电压降的比值的实部减去因过渡电阻引起的附加故障距离，得到输电线路保护安装处到相间短路故障点的故障距离。本发明方法克服了过渡电阻和负荷电流对单端故障测距精度的影响问题，输电线路相间高阻短路故障时本发明方法具有很高的测距精度，测距原理简单，程序实现容易，且无需采用搜索算法直接计算故障距离，测距速度快，实时性强。The method of the invention uses the negative sequence voltage between fault phases and the positive sequence impedance of the unit length transmission line to calculate the voltage phase angle of the short circuit fault point between phases, and then calculates the additional fault distance caused by the transition resistance, and uses the voltage between fault phases The voltage drop per unit length of the transmission line Subtracting the additional fault distance caused by the transition resistance from the real part of the ratio of , the fault distance from the transmission line protection installation to the phase-to-phase short-circuit fault point is obtained. The method of the present invention overcomes the problem of the influence of transition resistance and load current on the accuracy of single-ended fault distance measurement, and the method of the present invention has very high distance measurement accuracy when there is a high-resistance short-circuit fault between phases of the transmission line, the principle of distance measurement is simple, and the program is easy to implement, and There is no need to use search algorithms to directly calculate the fault distance, and the ranging speed is fast and the real-time performance is strong.

附图说明Description of drawings

图1为应用本发明的线路输电系统示意图。Fig. 1 is a schematic diagram of a line transmission system applying the present invention.

具体实施方式Detailed ways

下面根据说明书附图对本发明的技术方案做进一步详细表述。The technical solution of the present invention will be described in further detail below according to the accompanying drawings.

图1为应用本发明的线路输电系统示意图。图1中PT为电压互感器、CT为电流互感器。保护装置对输电线路保护安装处的电压互感器PT的电压波形和电流互感器CT的电流波形进行采样得到电压、电流瞬时值，并对其采样得到的电压、电流瞬时值利用傅里叶算法计算输电线路保护安装处的故障相间电压故障相间电流和故障相间负序电压其中，φφ＝AB、BC、CA相。Fig. 1 is a schematic diagram of a line transmission system applying the present invention. In Fig. 1, PT is a voltage transformer, and CT is a current transformer. The protection device samples the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT at the installation place of the transmission line protection to obtain the instantaneous value of the voltage and current, and calculates the instantaneous value of the voltage and current obtained by sampling using the Fourier algorithm Fault phase-to-phase voltage at transmission line protection installation Fault phase current and the negative sequence voltage between the faulted phases Among them, φφ=AB, BC, CA phase.

保护装置利用输电线路保护安装处的故障相间电压故障相间电流和故障相间负序电压计算因过渡电阻引起的附加故障距离Δx：The protection device uses the transmission line to protect the fault phase-to-phase voltage at the installation Fault phase current and the negative sequence voltage between the faulted phases Calculate the additional fault distance Δx due to transition resistance:

$Δx Δx = = - - \frac{Re Re [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ}}{{\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]] - - Im Im [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]]}{Im Im [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]] - - Re Re [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]]} Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ} {z z}_{11}}]]$

其中，z₁为单位长度输电线路正序阻抗；为的虚部；为的实部；为的实部；为的实部；为的虚部；Re[z₁]为z₁的实部；Im[z₁]为z₁的虚部；φφ＝AB、BC、CA相。Among them, z ₁ is the positive sequence impedance of the transmission line per unit length; for the imaginary part of for the real part of for the real part of for the real part of for The imaginary part; Re[z ₁ ] is the real part of z ₁ ; Im[z ₁ ] is the imaginary part of z ₁ ; φφ=AB, BC, CA phase.

由于因此，本发明方法利用减去因过渡电阻引起的附加故障距离Δx得到输电线路保护安装处到相间短路故障点的故障距离x：because Therefore, the method of the present invention utilizes Subtract the additional fault distance Δx caused by the transition resistance to obtain the fault distance x from the transmission line protection installation to the phase-to-phase short-circuit fault point:

$x x = = Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] + + \frac{Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]] - - Im Im [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]]}{Im Im [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]] - - Re Re [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]]} Re Re [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ} {z z}_{11}}]]$

其中，为的实部。in, for the real part of .

以上所述仅为本发明的较佳具体实施例，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，可轻易想到的变化或替换，都应涵盖在本发明的保护范围之内。The above descriptions are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto, any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention , should be covered within the protection scope of the present invention.

Claims

1. Utilize the real part characteristic of voltage drop to realize the fault single-ended ranging method between line phases, it is characterized in that, comprises the steps:

(1) The protection device samples the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT at the installation place of the transmission line protection to obtain the instantaneous value of the voltage and current, and uses Fourier to obtain the instantaneous value of the voltage and current obtained by sampling Leaf Algorithm Calculation of Fault Phase-to-Phase Voltage at Transmission Line Protection Installation Fault phase current and the negative sequence voltage between the faulted phases Among them, φφ=AB, BC, CA phase;

(2) The protection device uses the transmission line to protect the fault phase-to-phase voltage at the installation place Fault phase current and the negative sequence voltage between the faulted phases Calculate the additional fault distance Δx due to transition resistance:

Δx Δx = = - - \frac{Re Re [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ}}{{\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]] - - Im Im [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ}}{{\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]]}{Im Im [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]] - - Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]]} Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ} {z z}_{11}}]]

Among them, z ₁ is the positive sequence impedance of the transmission line per unit length; for the imaginary part of for the real part of for the real part of for the real part of for The imaginary part of; Re[z ₁ ] is the real part of z ₁ ; Im[z ₁ ] is the imaginary part of z ₁ ;

(3) Protection device utilization Subtract the additional fault distance Δx to obtain the fault distance x from the transmission line protection installation to the phase-to-phase short-circuit fault point:

x x = = Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] + + \frac{Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ}}{{\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]] - - Im Im [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ}}{{\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]]}{Im Im [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot &Center Dot;}{I I}}_{φφ φφ}}]] Re Re [[{z z}_{11}]] - - Re Re [[\frac{{\overset{\cdot &Center Dot;}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ}}]] Im Im [[{z z}_{11}]]} Re Re [[\frac{{\overset{\cdot \cdot}{U u}}_{φφ φφ 22}}{{z z}_{11} {\overset{\cdot \cdot}{I I}}_{φφ φφ} {z z}_{11}}]]

in, for the real part of .