CN110456123B - Broadband transient voltage division measuring device and method - Google Patents

Abstract

The invention discloses a broadband transient voltage partial pressure measuring device and a broadband transient voltage partial pressure measuring method, wherein the device comprises a high-voltage arm unit, a low-voltage arm unit and a high-voltage arm unit, wherein the high-voltage arm unit is used for dividing the high voltage of a measured line to obtain a divided low voltage and sending the divided low voltage to the low-voltage arm unit; a low-voltage arm unit for sending the divided low voltage to the broadband transient measurement unit; the broadband transient state measuring unit is used for measuring the divided voltage low voltage sent by the low-voltage arm unit and determining the high voltage of the measured line according to the divided voltage low voltage and a divided voltage ratio; the device adopts a low-inductance ceramic capacitor and a non-inductance resistor to carry out multistage series connection, and can be directly hung on a transmission line to measure the high voltage of a measured circuit in real time; the device can measure the amplitude of voltage, has high frequency band and is little influenced by the external environment; the real waveform of the overvoltage can be determined, and the method has important significance for safe and stable operation of the power transmission line.

Description

A broadband transient voltage divider measurement device and method

technical field

The present invention relates to the field of power systems, and more particularly, to a device and method for measuring broadband transient voltage division.

Background technique

In the power system, the transmission lines and substations will form overvoltage due to lightning intrusion or isolation knife switch operation, and the overvoltage will endanger the operation equipment of the transmission lines and substations. and safe and stable operation is of great significance. However, due to the high amplitude, wide frequency band, and unpredictable occurrence of the overvoltage, it is difficult to measure the overvoltage of the transmission line in real time. In the past, the research and analysis of overvoltage of transmission lines and substations were mostly based on simulation calculation. However, due to the difficulty of fully considering various complex influencing factors in the real situation in the simulation calculation process, the simulation results will be different from the actual operating conditions. The waveform parameters calculated by simulation can only be used as a reference, and there will be a certain gap with the real waveform. When there are differences in the simulation calculation modeling, the calculated overvoltage waveforms are very different, and it is difficult to evaluate the calculation accuracy.

In order to accurately measure the overvoltage waveform of the transmission line, the most intuitive method is to use a voltage divider for measurement, which requires the measurement of the frequency bandwidth of the voltage divider used: it is necessary to cover the measurement of the power frequency voltage to the overvoltage waveform at the front of the fast wave head, and the measurement amplitude High: It can cover the overvoltage amplitude from the rated power frequency operating voltage to (2~3) times the rated voltage.

At present, the method of real-time monitoring of overvoltage in substations mostly adopts the method of electric field sensor. The electric field sensor has the advantages of small size and convenient installation. However, in complex situations, the electric field sensor is easily disturbed by the surrounding environment. Except for the transmission line, other live It is also difficult to calibrate the voltage coefficient of the electric field sensor, so although the overvoltage waveform measured by the electric field sensor has more reference value than the waveform calculated by simulation, However, it still cannot fully reflect the real overvoltage waveform, and it is necessary to design a broadband transient voltage divider that can be directly connected to the transmission line for real-time monitoring.

SUMMARY OF THE INVENTION

In order to solve the problem in the background art that the existing technology cannot be directly connected to the transmission line to measure the high voltage of the circuit under test in real time, is greatly affected by the external environment and is difficult to determine the true waveform of the overvoltage, the present invention provides a broadband transient A voltage divider measurement device, the device includes:

A high-voltage arm unit, one end of the high-voltage arm unit is connected to the high-voltage line of the line under test, and the other end is connected to the low-voltage arm unit; the high-voltage arm unit is used to divide the high voltage of the line under test to obtain a divided low voltage , and send the divided low voltage to the low voltage arm unit;

A low-voltage arm unit, one end of the low-voltage arm unit is connected to the high-voltage arm unit and the broadband transient measurement unit respectively, and the other end is connected to the ground terminal; the low-voltage arm unit is used for sending the divided low voltage to the the broadband transient measurement unit;

A broadband transient measurement unit, one end of the broadband transient measurement unit is connected to the low-voltage arm unit; the broadband transient measurement unit is used to measure the divided low voltage sent by the low-voltage arm unit, and according to the The divided low voltage and the divided voltage ratio determine the high voltage amplitude and waveform of the line under test.

Further, the device includes M groups of high-voltage arm units; the M is a positive integer.

Further, the high-voltage arm unit includes N groups of high-voltage resistance-capacitance modules connected in series; the N is a positive integer.

Further, the low-voltage arm unit adopts a circuit model including a PCB.

Further, the low-voltage arm unit includes Q groups of low-voltage resistance-capacitance modules connected in parallel; the Q is a positive integer.

Further, the high-voltage RC module and the low-voltage RC module include low-inductance capacitors and non-inductive resistors.

Further, the capacitance value of the low-inductance capacitor and the resistance value of the non-inductance resistor in the high-voltage RC module make the RC time constant of the device less than P nanoseconds; the P is a positive number.

The method for measuring the voltage division of a broadband transient voltage includes:

According to the voltage level of the transmission line to be measured, it is determined that the high-voltage arm units in the broadband transient voltage divider measurement device are in M groups; the M is a positive integer;

connecting the high-voltage arm unit and the high-voltage terminal of the line to be measured, connecting the low-voltage arm unit and the ground terminal in the broadband transient voltage division measurement device, and connecting the low-voltage arm unit and the broadband transient measuring unit;

Collecting the high voltage of the transmission line to be measured, obtaining a divided low voltage after being divided by the high voltage arm unit and the low voltage arm unit, and sending the divided low voltage to the broadband transient measurement unit;

The amplitude and waveform of the high voltage of the transmission line to be tested are determined according to the divided low voltage and the divided voltage ratio.

Further, the high-voltage arm unit includes N groups of high-voltage resistance-capacitance modules connected in series; the N is a positive integer.

Further, the low-voltage arm unit includes Q groups of low-voltage resistance-capacitance modules connected in parallel; the Q is a positive integer.

The beneficial effects of the present invention are as follows: the technical solution of the present invention provides a broadband transient voltage division measurement device including a high-voltage arm unit, which is used to divide the high-voltage voltage of the line under test to obtain a divided voltage. Press down the voltage and send the divided low voltage to the low voltage arm unit; the low voltage arm unit is used to send the divided low voltage to the broadband transient measurement unit; the broadband transient measurement unit , the broadband transient measurement unit is used to measure the divided low voltage sent by the low voltage arm unit, and determine the high voltage of the line under test according to the divided low voltage and the voltage division ratio; the device adopts a low inductance Ceramic capacitors and non-inductive resistors are connected in multi-stage series, and can be directly connected to the transmission line to measure the high voltage of the circuit under test in real time; the amplitude of the measurable voltage is high, the frequency bandwidth is small, and the influence of the external environment is small; the device can determine the overvoltage It is of great significance to the safe and stable operation of transmission lines.

Description of drawings

Exemplary embodiments of the present invention may be more fully understood by reference to the following drawings:

FIG. 1 is a structural diagram of a broadband transient voltage divider measuring device according to a specific embodiment of the present invention;

FIG. 2 is a flowchart of a method for measuring broadband transient voltage division according to a specific embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for the purpose of this thorough and complete disclosure invention, and fully convey the scope of the invention to those skilled in the art. The terms used in the exemplary embodiments shown in the drawings are not intended to limit the invention. In the drawings, the same elements/elements are given the same reference numerals.

Unless otherwise defined, terms (including scientific and technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is to be understood that terms defined in commonly used dictionaries should be construed as having meanings consistent with the context in the related art, and should not be construed as idealized or overly formal meanings.

FIG. 1 is a structural diagram of a broadband transient voltage divider measurement device according to a specific embodiment of the present invention. As shown in Figure 1, the device includes:

High-voltage arm unit 1, one end of the high-voltage arm unit 1 is connected to the high-voltage line of the line under test, and the other end is connected to the low-voltage arm unit 2; the high-voltage arm unit 1 is used to divide the high voltage of the line under test. Obtain the divided low voltage, and send the divided low voltage to the low voltage arm unit 2;

Further, the number of groups of high-voltage arm units 1 can be flexibly selected according to the voltage level of the field test. In this example, three groups of high-voltage arm units 1 are used; the power frequency withstand voltage of each group of high-voltage arm units 1 is 150kV, which can withstand shock The voltage is 400kV;

Further, the high-voltage arm unit 1 is designed to be air-insulated, which is light in size and convenient for transportation and installation during field tests; in order to ensure the installation stability of the capacitive components of the high-voltage arm unit 1, a "ji"-shaped organic The glass bracket is used to fix the disc capacitive element of the high-voltage arm unit 1;

Further, the high-voltage arm unit includes N groups of high-voltage resistance-capacitance modules 12 connected in series; the N is a positive integer; in this example, 20 groups of high-voltage resistance-capacitance modules 12 connected in series are used;

Further, the high-voltage resistance-capacitance module 12 includes a low-inductance ceramic capacitor and a non-inductive resistor; in this example, the capacitance of each stage of the capacitor in the high-voltage resistance-capacitance module 12 is 3000pF, and the resistance value of each stage of resistance is 14Ω, ensuring that The RC time constant of the voltage divider is within 100ns;

Further, a cylindrical insulating connection block for fixing is installed between every two stages of capacitors in the high-voltage arm unit 1, and each stage of resistor components is arranged in a ring around the cylindrical insulating block in parallel, and the upper and lower ends of the non-inductive resistor are welded to metal copper. On the foil, the metal copper foil welded on both ends of the resistor is tightly connected with the upper and lower capacitors through nuts to reduce the stray inductance of the resistor components.

The low-voltage arm unit 2, one end of the low-voltage arm unit 2 is connected to the high-voltage arm unit 1 and the broadband transient measurement unit 3 respectively, and the other end is connected to the ground terminal; the low-voltage arm unit 2 is used to sending the depressed voltage to the broadband transient measurement unit 3;

Further, the low-voltage arm unit 2 adopts a circuit model including a disc type PCB;

Further, the low-voltage arm unit 2 includes Q groups of low-voltage resistance-capacitance modules 21 connected in parallel; the Q is a positive integer; the low-voltage resistance-capacitance module 21 includes a low-inductance ceramic capacitor and a non-inductive resistor, which can reduce the low-voltage arm unit 2 . The stray inductance parameters of the middle and middle components improve the frequency response characteristics of the device;

In this example, the low-voltage arm unit includes 25 groups of low-voltage RC modules 21 connected in parallel;

Further, in order to ensure good anti-electromagnetic interference characteristics of the low-voltage arm unit 2, the low-voltage arm unit 2 is installed in a metal shielding box.

A broadband transient measurement unit 3, one end of the broadband transient measurement unit 2 is connected to the low voltage arm unit 2; the broadband transient measurement unit 3 is used to measure the divided low voltage sent by the low voltage arm unit 2 , and determine the amplitude and waveform of the high voltage of the line under test according to the divided low voltage and the divided voltage ratio.

Further, the device is small in size, light in weight, and has a wide measurement frequency band, and can be used in substations of 220kV and below to realize on-line overvoltage monitoring of lines and calibration factor of electric field sensors.

FIG. 2 is a flowchart of a method for measuring broadband transient voltage division according to a specific embodiment of the present invention. As shown in Figure 2, the method includes:

Step 110: According to the voltage level of the transmission line to be measured, determine that the high-voltage arm units in the broadband transient voltage divider measurement device are in M groups; the M is a positive integer;

In this example, three groups of high-voltage arm units in the broadband transient voltage divider measurement device are determined according to the voltage level of the transmission line to be measured;

Step 120, connect each unit of the broadband transient voltage divider device; connect the high-voltage arm unit to the high-voltage terminal of the line to be measured, connect the low-voltage arm unit and the ground terminal of the broadband transient voltage divider measurement device, and connect the low-voltage arm unit and the broadband transient measurement unit;

Step 130: Collect the high voltage of the transmission line to be tested, obtain a divided low voltage after dividing the voltage by the high voltage arm unit and the low voltage arm unit, and send the divided low voltage to the broadband transient measurement unit;

Step 140: Determine the high voltage amplitude and waveform of the transmission line to be tested according to the divided low voltage and the divided voltage ratio;

In this example, the output cable of the broadband transient voltage divider measurement device is connected to the broadband transient measurement software; in the measurement software, the amplitude, polarity of the voltage to be measured, and the voltage of the broadband transient voltage divider measurement device are set. The voltage divider ratio and the total duration of the recording;

After the opening and closing operation in the substation, generate an overvoltage signal, observe and record the broadband transient voltage signal recorded by the broadband transient voltage divider measurement device, and perform parameter analysis on the recorded voltage waveform in the measurement software. .

Further, the high-voltage arm unit includes N groups of high-voltage resistance-capacitance modules connected in series; the N is a positive integer;

In this example, the high-voltage arm unit includes 20 sets of high-voltage resistance-capacitance modules connected in series.

Further, the low-voltage arm unit includes Q groups of low-voltage resistance-capacitance modules connected in parallel; the Q is a positive integer;

In this example, the low-voltage arm unit includes 25 groups of low-voltage RC modules connected in parallel.

In the description provided herein, numerous specific details are set forth. It will be understood, however, that embodiments of the present disclosure may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Those skilled in the art will understand that the modules in the device in the embodiment can be adaptively changed and arranged in one or more devices different from the embodiment. The modules or units or components in the embodiments may be combined into one module or unit or component, and further they may be divided into multiple sub-modules or sub-units or sub-assemblies. All features disclosed in this specification (including accompanying claims, abstract and drawings) and any method so disclosed may be employed in any combination, unless at least some of such features and/or procedures or elements are mutually exclusive. All processes or units of equipment are combined. Each feature disclosed in this specification (including accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. The step numbers involved in this specification are only used to distinguish each step, but not to limit the time or logical relationship between the steps. Unless clearly defined in the text, the relationship between the various steps includes various possible Happening.

Furthermore, those skilled in the art will appreciate that although some of the embodiments described herein include certain features, but not others, included in other embodiments, that combinations of features of different embodiments are intended to be within the scope of the present disclosure within and form different embodiments. For example, any of the embodiments claimed in the claims may be used in any combination.

Various component embodiments of the present disclosure may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. The present disclosure can also be implemented as an apparatus or system program (eg, computer programs and computer program products) for performing some or all of the methods described herein. Such a program implementing the present disclosure may be stored on a computer-readable medium, or may be in the form of one or more signals. Such signals may be downloaded from Internet sites, or provided on carrier signals, or in any other form.

It should be noted that the above-described embodiments illustrate rather than limit the disclosure, and that alternative embodiments may be devised by those skilled in the art without departing from the scope of the appended claims. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present disclosure may be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claim enumerating several systems, several of these systems can be embodied by one and the same item of hardware.

The above are only specific embodiments of the present disclosure. It should be pointed out that for those skilled in the art, several improvements, modifications, and variations can be made without departing from the spirit of the present disclosure. These improvements, Modifications and deformations should be regarded as falling within the protection scope of the present application.

Claims (10)

1. a broadband transient voltage divider measuring device, characterized in that the device comprises: A high-voltage arm unit, one end of the high-voltage arm unit is connected to the high-voltage line of the line under test, and the other end is connected to the low-voltage arm unit; the high-voltage arm unit is used to divide the high voltage of the line under test to obtain a divided low voltage , and send the divided low voltage to the low-voltage arm unit; wherein, a cylindrical insulating connection block for fixing is installed between every two stages of capacitors in the high-voltage arm unit, and each stage of resistance components is connected to the cylindrical insulating connection block. The periphery of the resistor is arranged in parallel in a ring, and the upper and lower ends of the non-inductive resistor are welded to the metal copper foil, and the metal copper foil welded at both ends of the resistor is tightly connected with the upper and lower capacitors through nuts; A low-voltage arm unit, one end of the low-voltage arm unit is connected to the high-voltage arm unit and the broadband transient measurement unit respectively, and the other end is connected to the ground terminal; the low-voltage arm unit is used for sending the divided low voltage to the The broadband transient measurement unit; wherein, the low-voltage arm unit is installed in a metal shielding box; A broadband transient measurement unit, one end of the broadband transient measurement unit is connected to the low-voltage arm unit; the broadband transient measurement unit is used to measure the divided low voltage sent by the low-voltage arm unit, and according to the The divided low voltage and the divided voltage ratio determine the high voltage amplitude and waveform of the line under test. 2 . The device according to claim 1 , wherein the device comprises M groups of high-voltage arm units; the M is a positive integer. 3 . 3 . The device according to claim 1 , wherein the high-voltage arm unit comprises N groups of high-voltage resistance-capacitance modules connected in series; the N is a positive integer. 4 . 4 . The device according to claim 1 , wherein the low-voltage arm unit adopts a circuit model including a PCB. 5 . 5 . The device according to claim 3 , wherein the low-voltage arm unit comprises Q groups of low-voltage resistance-capacitance modules connected in parallel; and the Q is a positive integer. 6 . 6 . The device of claim 5 , wherein the high-voltage RC module and the low-voltage RC module comprise low-inductance capacitors and non-inductive resistors. 7 . 7 . The device according to claim 6 , wherein the capacitance value of the low-inductance capacitor in the high-voltage RC module and the resistance value of the non-inductance resistor make the RC time constant of the device less than P nanometers 7 . seconds; the P is a positive number. 8. A method for measuring broadband transient voltage division, wherein the method comprises: According to the voltage level of the transmission line to be measured, it is determined that there are M groups of high-voltage arm units in the broadband transient voltage divider measurement device; the M is a positive integer; wherein, a fixed cylinder is installed between each two-stage capacitor in the high-voltage arm unit Each stage of resistance components is arranged in a ring around the cylindrical insulation connection block in parallel. The upper and lower ends of the non-inductive resistor are welded to the metal copper foil, and the metal copper foil welded at both ends of the resistor passes through the upper and lower capacitors. Nuts are tightly connected; connecting the high-voltage arm unit and the high-voltage terminal of the transmission line to be measured, connecting the low-voltage arm unit and the ground terminal in the broadband transient voltage division measurement device, and connecting the low-voltage arm unit and the broadband transient measuring unit; wherein , the low-voltage arm unit is installed in a metal shielding box; Collecting the high voltage of the transmission line to be measured, obtaining a divided low voltage after being divided by the high voltage arm unit and the low voltage arm unit, and sending the divided low voltage to the broadband transient measurement unit; The amplitude and waveform of the high voltage of the transmission line to be tested are determined according to the divided low voltage and the divided voltage ratio. 9 . The method according to claim 8 , wherein the high-voltage arm unit comprises N groups of high-voltage resistance-capacitance modules connected in series; the N is a positive integer. 10 . 10 . The method according to claim 8 , wherein the low-voltage arm unit comprises Q groups of low-voltage resistance-capacitance modules connected in parallel; and the Q is a positive integer. 11 .

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