阅读说明：本技术 一种基于准确测量电压的输电线路雷电故障定位方法 (Power transmission line lightning fault positioning method based on accurate voltage measurement ) 是由 刘红文 于广辉 王科 赵现平 聂鼎 于 2019-10-29 设计创作，主要内容包括：本申请提供了一种基于准确测量电压的输电线路雷电故障定位方法,当输电线路受到雷击时,雷击点将会出现较大的过电压,并且该过电压行波会以某一衰减系数向线路两侧衰减传播,通过对线路上不同位置处电压的准确测量,计算出线路电压衰减系数以及推算出故障发生的位置,提高雷电故障定位的速度和准确性。(The application provides a power transmission line lightning fault positioning method based on accurate voltage measurement, when a power transmission line is struck by lightning, a lightning stroke point can generate large overvoltage, the overvoltage traveling wave can be attenuated and transmitted to two sides of the line by a certain attenuation coefficient, the attenuation coefficient of the line voltage is calculated and the position of the fault is calculated by accurately measuring the voltage at different positions on the line, and the speed and the accuracy of lightning fault positioning are improved.)

1. A power transmission line lightning fault positioning method based on accurate voltage measurement is characterized by comprising the following steps:

acquiring real-time voltage waveform of a point to be measured on a transmission line;

Judging whether the current voltage of the point to be measured on the power transmission line is overvoltage or not according to the real-time voltage waveform of the point to be measured on the power transmission line;

If the current voltage of the point to be measured on the power transmission line is overvoltage, selecting a plurality of voltage acquisition points from two sides of the point to be measured on the power transmission line respectively;

calculating to obtain a voltage attenuation coefficient of the power transmission line according to the voltage values of the voltage acquisition points and the distance between the voltage acquisition points positioned on the same side of the point to be measured on the power transmission line;

And determining the position of the lightning fault of the power transmission line according to the voltage attenuation coefficient of the power transmission line and the distance between the voltage acquisition points positioned on the two sides of the point to be measured on the power transmission line.

2. the method of claim 1, wherein the step of calculating the voltage attenuation coefficient of the power transmission line according to the voltage values of the voltage acquisition points and the distance between the voltage acquisition points on the same side as the point to be measured on the power transmission line comprises the following steps:

Acquiring the voltage values of the voltage acquisition points and the distance between the voltage acquisition points positioned on the same side of the point to be measured on the power transmission line,

calculating to obtain a voltage attenuation coefficient of the power transmission line according to the voltage values of the voltage acquisition points and the distance between the voltage acquisition points positioned on the same side of the point to be measured on the power transmission line and according to the following formula;

Wherein, alpha represents the voltage attenuation coefficient of the first transmission line; beta represents a voltage attenuation coefficient of the second transmission line; u shape₁Representing a voltage value of a voltage acquisition point closest to a point to be measured on the power transmission line; u shape₁₁Represents and U₁The voltage values of the voltage acquisition points on the same side of the corresponding voltage acquisition points; l is₃Represents U₁Corresponding voltage acquisition point and U₁₁the distance between corresponding voltage collection points; u shape₂Represents and U₁The voltage value of a voltage acquisition point which is opposite to the corresponding voltage acquisition point and is closest to the point to be measured on the power transmission line; u shape₂₂Represents U₂Voltage value L of voltage acquisition point on the same side of corresponding voltage acquisition point₄Represents U₂Corresponding voltage acquisition point and U₂₂The distance between the corresponding voltage collection points.

3. The method of claim 2, wherein the determining the location of the transmission line lightning fault from the transmission line voltage attenuation coefficient and the distance between the voltage collection points on both sides of the point to be measured on the transmission line comprises:

calculating to obtain a line fault point distance U according to the power transmission line voltage attenuation coefficient and the distance between the voltage acquisition points positioned at two sides of the point to be measured on the power transmission line and the following formula₁Distance corresponding to the voltage acquisition point;

Wherein, alpha represents the voltage attenuation coefficient of the first transmission line; beta represents a voltage attenuation coefficient of the second transmission line; u shape₁Representing a voltage value of a voltage acquisition point closest to a point to be measured on the power transmission line; u shape₂Represents and U₁The voltage value of a voltage acquisition point which is opposite to the corresponding voltage acquisition point and is closest to the point to be measured on the power transmission line; l represents U₂Corresponding voltage acquisition point and U₁The distance between corresponding voltage collection points; l is₁Represents U₁And the distance between the corresponding voltage acquisition point and the point to be measured on the power transmission line.

Technical Field

The application relates to the technical field of lightning monitoring of power transmission lines of power systems, in particular to a lightning fault positioning method of a power transmission line based on accurate voltage measurement.

Background

Accidents in the power grid occupy a large proportion of faults of the power transmission lines, and faults of the power transmission lines occupy a large proportion of faults of lightning trip-out, particularly the power transmission lines in mountainous areas, and the faults of the power transmission lines are basically caused by the lightning trip-out. According to the operation record analysis, the point-based fault of the overhead transmission line is mainly characterized by strong seasonality, quick formation, great harm, difficult discovery of fault points and easy formation of invisible defects, and if the point-based fault is not eliminated in time, a continuous malignant fault can be caused, and a major accident can be caused to a power grid. At present, the accident occurrence place is difficult to find out only by a conventional tour method, and the fault is difficult to find out quickly and accurately.

Disclosure of Invention

The application provides a power transmission line lightning fault positioning method based on accurate voltage measurement, and aims to solve the problems that the accident occurrence place is difficult to find out and the fault is difficult to find out quickly and accurately only by means of a conventional inspection method.

The application provides a power transmission line lightning fault positioning method based on accurate voltage measurement, which comprises the following steps:

Acquiring real-time voltage waveform of a point to be measured on a transmission line;

judging whether the current voltage of the point to be measured on the power transmission line is overvoltage or not according to the real-time voltage waveform of the point to be measured on the power transmission line;

If the current voltage of the point to be measured on the power transmission line is overvoltage, selecting a plurality of voltage acquisition points from two sides of the point to be measured on the power transmission line respectively;

Calculating to obtain a voltage attenuation coefficient of the power transmission line according to the voltage values of the voltage acquisition points and the distance between the voltage acquisition points positioned on the same side of the point to be measured on the power transmission line;

And determining the position of the lightning fault of the power transmission line according to the voltage attenuation coefficient of the power transmission line and the distance between the voltage acquisition points positioned on the two sides of the point to be measured on the power transmission line.

According to the technical scheme, the lightning fault positioning method of the power transmission line based on the accurate voltage measurement is provided, when the power transmission line is struck by lightning, a lightning stroke point can generate large overvoltage, the overvoltage traveling wave can be attenuated and transmitted to two sides of the line by a certain attenuation coefficient, the attenuation coefficient of the line voltage is calculated and the position of the fault is calculated by accurately measuring the voltage at different positions on the line, and the speed and the accuracy of lightning fault positioning are improved.

Drawings

In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without any creative effort.

FIG. 1 is a flow chart of a method for locating a lightning fault of a power transmission line based on accurate voltage measurement according to the present application;

FIG. 2 is a block diagram of a transmission line lightning fault monitoring system;

FIG. 3 is a schematic diagram of power transmission line lightning stroke fault location.

Detailed Description

Referring to fig. 1, the present application provides a method for positioning a lightning fault of a power transmission line based on accurate voltage measurement, the method comprising:

Step 11: and acquiring the real-time voltage waveform of a point to be measured on the transmission line.

Referring to fig. 2, a ceramic capacitor core insulator string is installed at a point to be measured on a power transmission line, C1 is a high-voltage arm capacitor, C2 is a low-voltage arm capacitor, and the overvoltage monitoring device is used for monitoring the real-time voltage waveform of the point to be measured on the power transmission line and transmitting the real-time voltage waveform to the overvoltage transmission distribution characteristic and the lightning arrester monitoring system of the power transmission line through a wireless network.

Step 12: and judging whether the current voltage of the point to be measured on the power transmission line is overvoltage or not according to the real-time voltage waveform of the point to be measured on the power transmission line. And if the current voltage of the point to be measured on the power transmission line is overvoltage, executing the step 13.

Step 13: and respectively selecting a plurality of voltage acquisition points from two sides of the point to be measured on the power transmission line.

The overvoltage indicates that lightning stroke faults occur to the point to be measured, and the overvoltage can be transmitted to the two sides of the point to be measured through the power transmission line, so that a plurality of voltage collecting points are respectively selected on the two sides of the point to be measured on the power transmission line.

step 14: and calculating to obtain the voltage attenuation coefficient of the power transmission line according to the voltage values of the voltage acquisition points and the distance between the voltage acquisition points positioned on the same side of the point to be measured on the power transmission line.

Specifically, the voltage values of the voltage acquisition points and the distance between the voltage acquisition points positioned on the same side of the point to be measured on the power transmission line are acquired.

calculating to obtain a voltage attenuation coefficient of the power transmission line according to the voltage values of the voltage acquisition points and the distance between the voltage acquisition points positioned on the same side of the point to be measured on the power transmission line and according to the following formula;

wherein, alpha represents the voltage attenuation coefficient of the first transmission line; beta represents a voltage attenuation coefficient of the second transmission line; u shape₁to representThe voltage value of a voltage acquisition point closest to the point to be measured on the power transmission line; u shape₁₁Represents and U₁The voltage values of the voltage acquisition points on the same side of the corresponding voltage acquisition points; l is₃represents U₁Corresponding voltage acquisition point and U₁₁The distance between corresponding voltage collection points; u shape₂Represents and U₁the voltage value of a voltage acquisition point which is opposite to the corresponding voltage acquisition point and is closest to the point to be measured on the power transmission line; u shape₂₂Represents U₂Voltage value L of voltage acquisition point on the same side of corresponding voltage acquisition point₄Represents U₂Corresponding voltage acquisition point and U₂₂The distance between the corresponding voltage collection points.

For example, as shown in FIG. 3, A, B, C and D are voltage acquisition points located on both sides of the point to be measured, U₁₁Representing the voltage value, U, measured at point B₁Denotes the voltage value measured at point A, L₃represents the distance between two voltage acquisition points A and B, U₂The voltage value measured at the point C is represented; u shape₂₂Representing the voltage value, L, measured at point D₄The distance between the two voltage acquisition points C and D is shown.

step 15: and determining the position of the lightning fault of the power transmission line according to the voltage attenuation coefficient of the power transmission line and the distance between the voltage acquisition points positioned on the two sides of the point to be measured on the power transmission line.

Specifically, according to the voltage attenuation coefficient of the power transmission line and the distance between voltage acquisition points positioned on two sides of the point to be measured on the power transmission line, the line fault point distance U is calculated and obtained according to the following formula₁Distance corresponding to the voltage acquisition point;

Wherein, alpha represents the voltage attenuation coefficient of the first transmission line; beta represents a voltage attenuation coefficient of the second transmission line; u shape₁representing a voltage value of a voltage acquisition point closest to a point to be measured on the power transmission line; u shape₂represents and U₁the corresponding voltage acquisition point is opposite to one side and is far away from the power transmission line to be measuredThe voltage value of the voltage acquisition point closest to the point; l represents U₂Corresponding voltage acquisition point and U₁The distance between corresponding voltage collection points; l is₁Represents U₁And the distance between the corresponding voltage acquisition point and the point to be measured on the power transmission line. Continuing with the example of FIG. 3, L represents the distance between the two voltage acquisition points A and C; l is₁the distance between A and the point to be measured is indicated.

According to the technical scheme, the lightning fault positioning method of the power transmission line based on the accurate voltage measurement is provided, when the power transmission line is struck by lightning, a lightning stroke point can generate large overvoltage, the overvoltage traveling wave can be attenuated and transmitted to two sides of the line by a certain attenuation coefficient, the attenuation coefficient of the line voltage is calculated and the position of the fault is calculated by accurately measuring the voltage at different positions on the line, and the speed and the accuracy of lightning fault positioning are improved.