CN103207352B

CN103207352B - Route selection impedance magnitude characteristic is utilized to realize wire selection method for power distribution network single phase earthing failure

Info

Publication number: CN103207352B
Application number: CN201310079876.5A
Authority: CN
Inventors: 林富洪
Original assignee: State Grid Corp of China SGCC; 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; Putian Power Supply Co of State Grid Fujian Electric Power Co Ltd
Priority date: 2013-03-13
Filing date: 2013-03-13
Publication date: 2015-09-02
Anticipated expiration: 2033-03-13
Also published as: CN103207352A

Abstract

The invention discloses a method for realizing single-phase grounding fault line selection of a distribution network by using the impedance amplitude characteristic of line selection. This method measures the zero-sequence voltage of the distribution network busbar and the zero-sequence current of each feeder; if the zero-sequence voltage amplitude of the distribution network busbar is greater than 0.15 times the busbar phase voltage amplitude during normal operation of the distribution network, the parameters of the arc-suppression coil are kept unchanged. Change the switching parallel resistance, measure the zero-sequence voltage of the distribution network busbar and the zero-sequence current of each feeder again; calculate the line selection impedance amplitude of each feeder line in the distribution network, and use the line selection impedance amplitude corresponding to the normal feeder The corresponding line selection impedance amplitude is equal to the parallel resistance value, which is the characteristic of the line selection impedance amplitude to select the single-phase ground fault line of the distribution network. The fault line selection performance of the method of the present invention is not affected by factors such as feeder type, fault location, feeder line parameters, transition resistance, and feeder length. The operating environment of the distribution network has good engineering practical value.

Description

Realization of Line Selection Method for Single-phase-to-ground Fault in Distribution Network Using Line Selection Impedance Magnitude Characteristics

技术领域technical field

本发明涉及电力系统配电网故障选线技术领域，具体地说是涉及一种利用选线阻抗幅值特性实现配电网单相接地故障选线方法。The invention relates to the technical field of power system distribution network fault line selection, in particular to a method for realizing single-phase ground fault line selection of distribution network by using the line selection impedance amplitude characteristic.

背景技术Background technique

配电网馈线单相接地故障后，由于消弧线圈提供感性电流的补偿作用，引起流经故障馈线的零序电流量很小，故障特征不明显，使得选取配电网故障馈线存在较大困难。目前已提出的配电网馈线方法主要分为稳态法和暂态法。稳态法主要采用配电网馈线单相接地产生的稳态基频或各谐波电气信号完成故障选线功能，由于受配电网馈线单相高阻接地的故障特征不明显这一关键因素影响，该方法往往选线失败，不能适应现场实用需求。暂态法依据故障零序电流的暂态分量远大于稳态量的特点，结合利用一定选定频带内的暂态零模电压和电流完成故障选线功能，选线正确性高，然而暂态法对硬件和算法的可靠性要求过高，无法适应复杂的配电网环境，不能适应现场实用需求。After the single-phase grounding fault of the distribution network feeder, due to the compensation effect of the inductive current provided by the arc suppression coil, the zero-sequence current flowing through the fault feeder is very small, and the fault characteristics are not obvious, which makes it difficult to select the fault feeder of the distribution network . The proposed distribution network feeder methods are mainly divided into steady state method and transient state method. The steady-state method mainly uses the steady-state fundamental frequency or harmonic electrical signals generated by the single-phase grounding of the distribution network feeder to complete the fault line selection function. This method often fails in line selection and cannot meet the practical needs of the site. The transient method is based on the fact that the transient component of the fault zero-sequence current is much larger than the steady-state value, and uses the transient zero-mode voltage and current in a certain selected frequency band to complete the function of fault line selection. The correctness of line selection is high, but the transient state The method has too high requirements on the reliability of hardware and algorithms, and cannot adapt to the complex distribution network environment, and cannot adapt to the practical needs of the field.

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，提供一种可靠正确选线，适应复杂配电网运行环境的利用选线阻抗幅值特性实现配电网单相接地故障选线方法。The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a reliable and correct line selection method for single-phase grounding fault line selection in the distribution network by utilizing the line selection impedance amplitude characteristics and adapting to the complex distribution network operating environment.

本发明的目的是通过以下途径实现的：The purpose of the present invention is achieved by the following approach:

利用选线阻抗幅值特性实现配电网单相接地故障选线方法，其要点在于，包括如下步骤：The key point of realizing the single-phase ground fault line selection method of distribution network by using the impedance amplitude characteristic of line selection is that it includes the following steps:

(1)提供一种测量装置，其测量配电网母线零序电压和各馈线零序电流若大于则投切并联电阻，再次测量配电网母线零序电压和各馈线零序电流其中，i为第i条馈线编号，i＝1，...,n，n为配电网馈线数目，为配电网正常运行时的母线相电压；并联电阻在电气结构上与消弧线圈并联连接；(1) Provide a measuring device that measures the zero-sequence voltage of the distribution network bus and zero-sequence current of each feeder like more than the Then switch the parallel resistance and measure the zero-sequence voltage of the distribution network bus again and zero-sequence current of each feeder Among them, i is the i-th feeder number, i=1,...,n, n is the number of distribution network feeders, is the phase voltage of the busbar during the normal operation of the distribution network; the parallel resistor is connected in parallel with the arc suppression coil in the electrical structure;

(2)提供一种数据处理装置，其根据测量装置测量到的数据对i从1到n依次计算配电网各馈线的选线阻抗其中，i为第i条馈线编号，i＝1，...,n，n为配电网馈线数目；(2) Provide a data processing device, which calculates the line selection impedance of each feeder line of the distribution network sequentially from 1 to n according to the data measured by the measuring device Among them, i is the i-th feeder number, i=1,...,n, n is the number of distribution network feeders;

(3)数据处理装置设定整定阻抗值Z_set，选取选线阻抗幅值满足对应的配电网馈线为故障馈线；其中，i为第i条馈线编号，i＝1，...,n，n为配电网馈线数目。(3) The data processing device sets the impedance value Z _set , and selects the line selection impedance amplitude to satisfy The corresponding distribution network feeder is a fault feeder; wherein, i is the number of the i-th feeder, i=1,...,n, n is the number of distribution network feeders.

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:

本发明方法根据正常馈线对应的选线阻抗幅值为无穷大、故障馈线对应的选线阻抗幅值等于并联电阻值这一选线阻抗幅值特性实现配电网单相接地故障选线，选线性能不受馈线类型、故障位置、馈线线路参数、过渡电阻和馈线长度等因素影响，配电网单相高阻接地故障时本发明方法能可靠正确选线，适应复杂配电网运行环境，具有良好工程实用价值。The method of the invention realizes single-phase grounding fault line selection of distribution network according to the line selection impedance amplitude characteristic corresponding to the normal feeder line is infinite, and the line selection impedance amplitude corresponding to the fault feeder is equal to the parallel resistance value. The performance is not affected by factors such as feeder type, fault location, feeder line parameters, transition resistance and feeder length, and the method of the present invention can reliably and correctly select the line when a single-phase high-impedance grounding fault occurs in the distribution network, adapting to the complex operating environment of the distribution network, and has the advantages of Good engineering practical value.

附图说明Description of drawings

图1为应用本发明方法的并联电阻投切前的配电网单相接地故障零序序网图。Fig. 1 is a zero-sequence network diagram of a single-phase-to-ground fault in a distribution network before parallel resistor switching using the method of the present invention.

图2为应用本发明方法的并联电阻投切后的配电网单相接地故障零序序网图。Fig. 2 is a zero-sequence network diagram of a single-phase-to-ground fault in a distribution network after parallel resistor switching using the method of 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 further described in detail according to the accompanying drawings.

本实施例以中性点经消弧线圈接地的配电网第n条馈线发生单相接地故障为例进一步阐述本发明技术方案。This embodiment further illustrates the technical solution of the present invention by taking a single-phase ground fault occurring on the nth feeder line of the distribution network whose neutral point is grounded through an arc suppressing coil as an example.

图1为并联电阻投切前的配电网单相接地故障零序序网图。图1中的为配电网母线注入消弧线圈的零序电流。测量配电网母线零序电压测量第1、2、...、n-1、n条馈线流过的零序电流其中，n为配电网馈线数目。Figure 1 is a zero-sequence network diagram of a single-phase-to-ground fault in a distribution network before shunt resistor switching. in Figure 1 Inject the zero-sequence current of the arc-suppression coil into the busbar of the distribution network. Measuring the zero-sequence voltage of distribution network bus Measure the zero-sequence current flowing through the 1st, 2nd, ..., n-1, n feeders Among them, n is the number of distribution network feeders.

若大于投切并联电阻R；其中，为正常运行时配电网母线相电压，并联电阻R在电气结构上与消弧线圈L并联连接。like more than the Switching parallel resistance R; where, For the distribution network bus phase voltage during normal operation, the parallel resistor R is connected in parallel with the arc suppression coil L in the electrical structure.

图2为并联电阻投切后的配电网单相接地故障零序序网图。图2中的为并联电阻投切后的配电网母线注入消弧线圈与并联电阻的零序电流。测量配电网母线零序电压测量第1、2、...、n-1、n条馈线流过的零序电流其中，n为配电网馈线数目。Figure 2 is a zero-sequence network diagram of a single-phase-to-ground fault in a distribution network after switching resistors in parallel. in Figure 2 The zero-sequence current of the arc suppressing coil and the parallel resistor is injected into the busbar of the distribution network after the parallel resistor is switched. Measuring the zero-sequence voltage of distribution network bus Measure the zero-sequence current flowing through the 1st, 2nd, ..., n-1, n feeders Among them, n is the number of distribution network feeders.

计算并联电阻R投切后的配电网第1、2、...、n-1、n条馈线的选线阻抗幅值：Calculate the line selection impedance amplitude of the 1st, 2nd, ..., n-1, n feeder lines of the distribution network after the parallel resistance R is switched:

$| | {Z Z}_{11} | | = = | | \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{I I}}_{0101}^{22} - - \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot \cdot}{U u}}_{00}^{11}} {\overset{\cdot \cdot}{I I}}_{0101}^{11}} | | = = | | \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{I I}}_{0101}^{22} - - \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot \cdot}{U u}}_{00}^{11}} {Y Y}_{0101} {\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} | | = = \frac{| | {\overset{\cdot \cdot}{U u}}_{00}^{22} | |}{| | {\overset{\cdot &Center Dot;}{U u}}_{00}^{22} {Y Y}_{0101} - - {\overset{\cdot &Center Dot;}{U u}}_{00}^{22} {Y Y}_{0101} | |} = = \frac{| | {\overset{\cdot \cdot}{U u}}_{00}^{22} | |}{00} = = \infty \infty$

$| | {Z Z}_{22} | | = = | | \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{I I}}_{0202}^{22} - - \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} {\overset{\cdot &Center Dot;}{I I}}_{0202}^{11}} | | = = | | \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot \cdot}{I I}}_{0202}^{22} - - \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} {Y Y}_{0202} {\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} | | = = \frac{| | {\overset{\cdot \cdot}{U u}}_{00}^{22} | |}{| | {\overset{\cdot \cdot}{U u}}_{00}^{22} {Y Y}_{0202} - - {\overset{\cdot \cdot}{U u}}_{00}^{22} {Y Y}_{0202} | |} = = \frac{| | {\overset{\cdot &Center Dot;}{U u}}_{00}^{22} | |}{00} = = \infty \infty$

$| | {Z Z}_{33} | | = = | | \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{I I}}_{0303}^{22} - - \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} {\overset{\cdot &Center Dot;}{I I}}_{0303}^{11}} | | = = | | \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{I I}}_{0303}^{22} - - \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} {Y Y}_{0303} {\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} | | = = \frac{| | {\overset{\cdot &Center Dot;}{U u}}_{00}^{22} | |}{| | {\overset{\cdot &Center Dot;}{U u}}_{00}^{22} {Y Y}_{0303} - - {\overset{\cdot &Center Dot;}{U u}}_{00}^{22} {Y Y}_{0303} | |} = = \frac{| | {\overset{\cdot &Center Dot;}{U u}}_{00}^{22} | |}{00} = = \infty \infty$

……...

$| | {Z Z}_{n no - - 11} | | = = | | \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot \cdot}{I I}}_{00 n no - - 11}^{22} - - \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} {\overset{\cdot \cdot}{I I}}_{00 n no - - 11}^{11}} | | = = | | \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{I I}}_{00 n no - - 11}^{22} - - \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot \cdot}{U u}}_{00}^{11}} {Y Y}_{00 n no - - 11} {\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} | | = = \frac{| | {\overset{\cdot &Center Dot;}{U u}}_{00}^{22} | |}{| | {\overset{\cdot \cdot}{U u}}_{00}^{22} {Y Y}_{00 n no - - 11} - - {\overset{\cdot \cdot}{U u}}_{00}^{22} {Y Y}_{00 n no - - 11} | |} = = \frac{| | {\overset{\cdot &Center Dot;}{U u}}_{00}^{22} | |}{00} = = \infty \infty$

$| | {Z Z}_{n no} | | = = | | \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{{\overset{\cdot \cdot}{I I}}_{00 n no}^{22} - - \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} {\overset{\cdot \cdot}{I I}}_{00 n no}^{11}} | | = = \frac{| | {\overset{\cdot \cdot}{U u}}_{00}^{22} | |}{| | - - \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{R R} | |} = = R R - - - - - - ((11))$

其中，R为并联电阻；Y₀₁、Y₀₂、Y₀₃、……、Y_0n-1分别表示第1、2、3、……、n-1条馈线的对地导纳。Among them, R is the parallel resistance; Y ₀₁ , Y ₀₂ , Y ₀₃ , ..., Y _0n-1 represent the ground admittance of the 1st, 2nd, 3rd, ..., n-1 feeders respectively.

由上述分析可知，第1、2、...、n-1条馈线对应的选线阻抗幅值为无穷大数值，第n条馈线对应的选线阻抗幅值等于并联电阻值，即正常馈线对应的选线阻抗幅值为无穷大数值，故障馈线对应的选线阻抗幅值等于并联阻抗值，因此本发明方法利用选线阻抗此幅值特性构成配电网故障选线判据如下：From the above analysis, it can be seen that the line selection impedance amplitude corresponding to the 1st, 2nd, ..., n-1 feeders is an infinite value, and the line selection impedance amplitude corresponding to the nth feeder is equal to the parallel resistance value, that is, the normal feeder corresponds to The magnitude of the line selection impedance is an infinite value, and the line selection impedance magnitude corresponding to the fault feeder is equal to the parallel impedance value, so the method of the present invention utilizes this amplitude characteristic of the line selection impedance to form the distribution network fault line selection criterion as follows:

$| | {Z Z}_{i i} | | = = | | \frac{{\overset{\cdot \cdot}{U u}}_{00}^{22}}{{\overset{\cdot \cdot}{I I}}_{00 i i}^{22} - - \frac{{\overset{\cdot &Center Dot;}{U u}}_{00}^{22}}{{\overset{\cdot &Center Dot;}{U u}}_{00}^{11}} {\overset{\cdot &Center Dot;}{I I}}_{00 i i}^{11}} | | < < {Z Z}_{set set},,$

其中，Z_set为整定阻抗值，i为第i条馈线编号，i＝1，...,n，n为配电网馈线数目，于是，选取选线阻抗幅值满足对应的配电网馈线为故障馈线。Among them, Z _set is the setting impedance value, i is the number of the i-th feeder, i=1,...,n, n is the number of feeders in the distribution network, so the selected line impedance amplitude satisfies The corresponding distribution network feeder is the fault feeder.

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 line selection impedance amplitude characteristic to realize the single-phase grounding fault line selection method of distribution network, it is characterized in that, comprises the following steps:

(1) Provide a measuring device that measures the zero-sequence voltage of the distribution network bus and zero-sequence current of each feeder like more than the Then switch the parallel resistance and measure the zero-sequence voltage of the distribution network bus again and zero-sequence current of each feeder Among them, i is the i-th feeder number, i=1,...,n, n is the number of distribution network feeders, is the phase voltage of the busbar during the normal operation of the distribution network; the parallel resistor is connected in parallel with the arc suppression coil in the electrical structure;

(2) Provide a data processing device, which calculates the line selection impedance of each feeder line of the distribution network sequentially from 1 to n according to the data measured by the measuring device Where, i is the number of the i-th feeder, i=1,...,n, n is the number of distribution network feeders;

(3) The data processing device sets the impedance value Z _set , and selects the line selection impedance amplitude to satisfy The corresponding distribution network feeder is a fault feeder; where, i is the number of the i-th feeder, i=1,...,n, n is the number of distribution network feeders.