CN118746732A - Partial discharge detection equipment - Google Patents

Abstract

The present application relates to a partial discharge detection device. The device includes an inductor coil and an inductor detection device; the inductor coil is connected in parallel with the inductor detection device; the inductor coil and the target metal set on the external insulating shell of the insulating device to be detected are set opposite to each other; when the external insulating shell of the insulating device to be detected is damaged, the eddy current generated by the target metal changes the inductance value of the inductor coil; the inductor detection device is used to periodically detect the inductance value of the inductor coil; wherein the inductance value represents the partial discharge condition of the insulating device to be detected. The present application determines the partial discharge condition through the mutual inductance effect, and external interference will not affect the mutual inductance effect. Therefore, external interference can be avoided, thereby improving the accuracy of determining the partial discharge condition.

Description

Partial discharge detection equipment

Technical Field

The present application relates to the field of computer technology, and in particular to a partial discharge detection device.

Background Art

With the development of the power industry, gas insulated switchgear (Gas Insulated Substation) has been increasingly widely used in power grids due to its high reliability, small size, and simple maintenance. GIS equipment inevitably has defects during manufacturing, transportation, and installation. These defects include metal burrs, protrusions, or suspended particles. In long-term operation, these potential defects can cause partial discharge.

The main reason for partial discharge in GIS equipment is the insulation defects caused by the production process, transportation and installation of the equipment. Once the GIS equipment has insulation defects, it will be easily affected by the electric field and partial discharge will occur, which will seriously cause insulation damage to the equipment. Partial discharge is not only a precursor to insulation defects in power equipment, but also a cause of insulation degradation.

In the prior art, partial discharge detection of GIS equipment is usually performed by ultrasonic detection or ultra-high frequency detection. However, the ultrasonic detection method is greatly interfered by external noise, and the vibration in the environment will bring huge noise, so that the vibration caused by partial discharge is drowned by the noise; and the ultra-high frequency method is limited by the large size of the detection antenna and the need for electrical connection, which cannot be placed inside the GIS equipment for measurement. Therefore, no matter which detection method is used, there is a problem that it is greatly interfered by the outside world, resulting in inaccurate partial discharge detection results.

Summary of the invention

Based on this, it is necessary to provide a partial discharge detection device that can accurately detect partial discharge in order to solve the above technical problems.

In a first aspect, the present application provides a partial discharge detection device, including an inductor coil and an inductor detection device;

The inductance coil is connected in parallel with the inductance detection device;

The inductor coil and the target metal provided on the outer insulating shell of the insulating device to be detected are arranged opposite to each other;

When the outer insulating shell of the insulating device to be tested is damaged, the eddy current generated by the target metal changes the inductance value of the inductor coil;

The inductance detection device is used to periodically detect the inductance value of the inductance coil; wherein the inductance value represents the partial discharge condition of the insulation equipment to be detected.

In one of the embodiments, the inductance monitoring device determines the degree of partial discharge of the insulation equipment to be detected according to the inductance value of the inductor coil at different cycles.

In one embodiment, the device further includes a signal generator; the signal generator is connected in parallel with the inductor coil and is used to provide an AC signal to the inductor coil.

In one of the embodiments, the device further includes a phase analysis device; the phase analysis device is connected to the inductance monitoring device and is used to determine the discharge phase according to the phase difference between the inductance change of the inductor coil in different cycles and the standard AC signal.

In one embodiment, the standard AC signal is a sinusoidal AC signal with a frequency of 50 Hz.

In one of the embodiments, the device further includes a voltage transformer; the voltage transformer is connected to the phase analysis device and is used to provide a standard AC signal to the phase analysis device.

In one of the embodiments, the voltage transformer is a terminal box.

In one embodiment, the insulating equipment to be inspected is a gas-insulated switchgear.

In one embodiment, the inductance detection device is a digital bridge.

In a second aspect, the present application also provides a partial discharge detection system, including a discharge detection device and an insulation device to be detected;

The inductor coil is arranged opposite to the target metal provided on the outer insulating shell of the insulating device to be detected;

When the outer insulating shell of the insulating device to be tested is damaged, the eddy current generated by the target metal changes the inductance value of the inductor coil;

The inductance detection device is used to periodically detect the inductance value of the inductance coil; wherein the inductance value represents the partial discharge condition of the insulation equipment to be detected.

The above-mentioned partial discharge detection equipment includes an inductor coil and an inductor detection device; the inductor coil is connected in parallel with the inductor detection device; the inductor coil and the target metal set on the external insulating shell of the insulating device to be detected are set opposite to each other; when the external insulating shell of the insulating device to be detected is damaged, the eddy current generated by the target metal changes the inductance value of the inductor coil; the inductor detection device is used to periodically detect the inductance value of the inductor coil; wherein the inductance value represents the partial discharge condition of the insulating device to be detected. The present application determines the partial discharge condition through the mutual inductance effect, and external interference will not affect the mutual inductance effect. Therefore, external interference can be avoided, thereby improving the accuracy of determining the partial discharge condition.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a structural diagram of a partial discharge detection device in a first embodiment;

FIG2 is a structural diagram of a partial discharge detection device in a second embodiment;

FIG3 is a circuit diagram of a partial discharge detection device in one embodiment;

FIG4 is a structural diagram of a partial discharge detection device in a third embodiment;

FIG5 is a structural diagram of a partial discharge detection device in a fourth embodiment;

FIG. 6 is a structural diagram of a partial discharge detection system in one embodiment.

Description of reference numerals:

1: discharge detection equipment; 11: inductor coil;

12: signal generator; 13: inductance detection device;

14: Phase analysis device; 15: Terminal box;

2: Insulation equipment to be tested.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the term "including" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

In actual applications, gas-insulated switchgear may have insulation defects due to the production process, transportation and installation of equipment. Once the gas-insulated switchgear has insulation defects, it will be easily affected by the electric field and prone to partial discharge, which may seriously cause insulation damage to the equipment. Partial discharge is both a precursor to insulation defects in gas-insulated switchgear and a cause of insulation degradation.

Based on this, in one embodiment, as shown in FIG1 , a partial discharge detection device 1 is provided, which includes an inductor 11 and an inductor detection device 13; the inductor 11 and the inductor detection device 13 are connected in parallel; the inductor 11 and the target metal set on the outer insulating shell of the insulating device 2 to be detected are set opposite to each other; when the outer insulating shell of the insulating device 2 to be detected is damaged, the eddy current generated by the target metal changes the inductance value of the inductor 11; the inductor detection device 13 is used to periodically detect the inductance value of the inductor 11. The inductor monitoring device 13 determines the partial discharge degree of the insulating device 2 to be detected according to the inductance value of the inductor 11 in different periods.

The inductance value represents the partial discharge condition of the insulation device 2 to be detected. The insulation device 2 to be detected is a gas insulated switchgear. The inductance detection device 13 is a digital bridge.

Exemplarily, the insulating device to be tested may be a gas insulated switchgear in a gas insulated switchgear. Gas insulated switchgear (GIS) consists of a circuit breaker, a disconnector, a grounding switch, a current transformer, a voltage transformer, a lightning arrester, a busbar, connectors, and outlet terminals. These devices or components are all enclosed in a metal grounded casing, which is filled with insulating gas at a certain pressure, so it is also called a fully enclosed combination electrical appliance.

Exemplarily, the inductance detection device can be a digital bridge. A digital bridge is an instrument that can measure inductance, capacitance, resistance, and impedance. This is a traditional saying. The earliest impedance measurement used a real bridge method. It can be used for the calibration and transfer of impedance measuring tools in the metrology and testing department, as well as for routine measurement of impedance elements in general departments. Many digital bridges have standard interfaces that can automatically grade the measured components according to the accuracy of the measured values; they can also be directly connected to the automatic test system for automatic inspection of products on the component production line to achieve quality control of the production process.

Specifically, the inductor coil and the inductor detection device are connected in parallel, and the inductor coil and the target metal set on the external insulating shell of the insulating device to be detected are set oppositely. When the external insulating shell of the insulating device to be detected is not damaged, there will be no current on the external insulating shell of the insulating device to be detected, so no eddy current will be formed. However, when the external insulating shell of the insulating device to be detected is damaged, there will be current on the external insulating shell of the insulating device to be detected due to leakage. At this time, the part of the external insulating shell where the current exists is the target metal, and the charged metal will produce an eddy current effect with the inductor coil, so eddy current will be generated on the target metal, which in turn changes the inductance value of the inductor coil through coupling. The inductor detection device will periodically detect the inductance value of the inductor coil. When there is an inductance value or there is a significant difference in the inductance value (such as when the difference between the detected inductance value and the preset standard inductance value is greater than the preset threshold), it is judged that the external insulating shell corresponding to the target metal in the insulating device to be detected has a partial discharge.

The above-mentioned partial discharge detection equipment includes an inductor coil and an inductor detection device; the inductor coil is connected in parallel with the inductor detection device; the inductor coil and the target metal set on the external insulating shell of the insulating device to be detected are set opposite to each other; when the external insulating shell of the insulating device to be detected is damaged, the eddy current generated by the target metal changes the inductance value of the inductor coil; the inductor detection device is used to periodically detect the inductance value of the inductor coil; wherein the inductance value represents the partial discharge condition of the insulating device to be detected. The present application determines the partial discharge condition through the mutual inductance effect, and external interference will not affect the mutual inductance effect. Therefore, external interference can be avoided, thereby improving the accuracy of determining the partial discharge condition.

It should be noted that compared with other GIS partial discharge detection devices, the signal readout circuit size of the present invention is very small. The present application can place the inductor coil outside the GIS equipment to achieve wireless signal transmission, without the need to open holes in the GIS box to affect the normal operation of the GIS equipment. The present application converts vibration physical quantities into electrical quantities, solving the problem that ultrasonic measurement is susceptible to external vibration interference. The target metal and processing circuit of the present application are both outside the GIS metal box, avoiding the inconvenience of installing power supplies, wires, etc. inside the GIS equipment. Compared with optical and laser sensors, the electrical equipment control system of the present application is low-cost.

It should be noted that the electrical equipment control system has inherent robustness in harsh environments and is insensitive to pollutants (such as dirt, dust, oil, humidity or any non-conductive materials). The electrical equipment control system (Electric Control System, ECS) is generally called the secondary control circuit of electrical equipment. Different equipment has different control circuits, and the control methods of high-voltage electrical equipment and low-voltage electrical equipment are also different. Specifically, the electrical control system refers to a combination of several electrical components used to achieve control of one or some objects, thereby ensuring the safe and reliable operation of the controlled equipment. Its main functions are: automatic control, protection, monitoring and measurement. The main application objects are the switch closing and opening of power plants, the display and alarm of the switch status and the status of power generation equipment, and the real-time display of analog quantities. Specifically, the automatic control function: the volume of high-voltage and high-current switchgear is very large, and generally an operating system is used to control the opening and closing of the switch. In particular, when the equipment fails, the switch needs to automatically cut off the circuit. There must be a set of automatic control electrical operating equipment to automatically control the power supply equipment. Protection function: electrical equipment and lines may fail during operation, and the current (or voltage) may exceed the range and limit of the equipment and lines. This requires a set of protection equipment that detects these fault signals and automatically adjusts the equipment and lines (disconnection, switching, etc.). Monitoring function: electricity is invisible to the naked eye. It is impossible to tell from the outside whether a device is powered on or off. This requires the setting of various audio-visual signals, such as lights and sounds, to conduct electrical monitoring of primary equipment. Measurement function: Lights and sound signals can only qualitatively indicate the working status of the equipment (powered on or off). If you want to quantitatively know the working status of the electrical equipment, you also need various instrument measurement equipment to measure various parameters of the line, such as voltage, current, frequency, and power.

In order to expand the detection range of the partial discharge detection device, based on the above embodiment, as shown in FIG. 2 , the partial discharge detection device further includes a signal generator 12 ; the signal generator 12 is connected in parallel with the inductor 11 to provide an AC signal to the inductor 11 .

For example, a signal generator is a device that can provide electrical signals of various frequencies, waveforms and output levels. It is used as a test signal source or excitation source when measuring the amplitude characteristics, frequency characteristics, transmission characteristics and other electrical parameters of various telecommunication systems or telecommunication equipment, as well as measuring the characteristics and parameters of components. Signal generators, also known as signal sources or oscillators, are widely used in production practice and science and technology. Various waveform curves are represented by trigonometric function equations. A circuit that can generate a variety of waveforms, such as triangular waves, sawtooth waves, rectangular waves (including square waves), and sine waves is called a function signal generator.

Specifically, the signal generator is connected in parallel with the inductor coil, and the signal generator provides an AC signal to the inductor coil, and also provides an AC signal to the inductor detection device, so that the inductor detection device can operate. The inductor coil and the target metal set on the external insulating shell of the insulating device to be detected are set opposite to each other. When the external insulating shell of the insulating device to be detected is not damaged, there will be no current on the external insulating shell of the insulating device to be detected, and therefore no eddy current will be formed. However, when the external insulating shell of the insulating device to be detected is damaged, there will be current on the external insulating shell of the insulating device to be detected due to leakage. At this time, the part of the external insulating shell where the current exists is the target metal, and the charged metal will produce an eddy current effect with the inductor coil, so eddy current will be generated on the target metal, and then in turn, the inductance value of the inductor coil will be changed through coupling. The inductance detection device will periodically detect the inductance value of the inductor coil. When there is an inductance value or there is a significant difference in the inductance value, it is judged that there is a partial discharge in the external insulating shell corresponding to the target metal in the insulating device to be detected.

Exemplarily, FIG3 is a circuit diagram of a partial discharge detection device in one embodiment. Rt in FIG3 is the inherent resistance value of the target metal in the insulation device to be detected, and _Lt is the inductance coil equivalent to the target metal in the insulation device to be detected. The LCR analyzer in FIG3 is the signal analyzer in the partial discharge detection device, the signal generator is the signal generator in the partial discharge detection device, and _Lc is the inductance coil in the partial discharge detection device. _M12 is the mutual inductance between the insulation device to be detected and the partial discharge detection device.

This embodiment can make the determined partial discharge situation more accurate.

In order to expand the detection range of the above-mentioned partial discharge detection equipment, on the basis of the above-mentioned embodiment, as shown in Figure 3, the partial discharge detection also includes a phase analysis device 14; the phase analysis device 14 is connected to the inductance monitoring device 13, and is used to determine the discharge phase according to the phase difference between the inductance change of the inductor coil 11 in different periods and the standard AC signal.

Exemplarily, the phase analysis device can be a phase analyzer. The phase meter is a new generation of instrument for electric power system energy metering and relay protection, and for on-site detection of secondary circuits. It is also widely used in electrical equipment manufacturing, petrochemical industry, steel metallurgy, railway electrification, scientific research and teaching and other departments, and has the following uses: Detect the phase relationship between each group of CTs in relay protection. Check whether the wiring of the watt-hour meter is correct. Determine the speed of the watt-hour meter and collect electricity charges reasonably. Discrimination of inductive and capacitive circuits. Check the wiring group of the transformer. Measurement of current and voltage phase in electrical equipment production. Used as a leakage current meter, etc.

Specifically, the phase analysis device is connected to the inductance monitoring device, and the phase analysis device receives the inductance change sent by the inductance monitoring device. The phase analysis device determines the specific phase information of the discharge in the target metal through a graph analysis based on the phase difference between the inductance change of the inductance coil in different cycles and the standard AC signal, and then determines the discharge phase.

Exemplarily, the atlas method in this embodiment can be a phase-resolved partial discharge atlas (PRPD), which displays each local discharge pulse with a phase mark according to the phase. The discharge information has no time information and belongs to the superposition of information within a period of time, such as within 1 second. It includes three categories: "end-transverse magnetic vector destruction type gradient echo imaging", "steady-state free precession imaging", and "balanced gradient magnetic field steady-state free precession imaging". Generally speaking, the narrow "gradient echo magnetic resonance pulse sequence" refers to the "end-transverse magnetic vector destruction type gradient echo imaging". "Han Huixun" and its imaging versions, "spin echo magnetic resonance pulse sequence", "spin echo magnetic resonance pulse sequence", and more broadly include the "fast spin echo magnetic resonance pulse sequence" in magnetic resonance imaging.

This embodiment can make the determined partial discharge situation more accurate.

In order to expand the detection range of the above partial discharge detection device, on the basis of the above embodiment, as shown in FIG. 4 , the partial discharge detection device further includes a voltage transformer 15 ; the voltage transformer 15 is connected to the phase analysis device 14 to provide a standard AC signal to the phase analysis device 14 .

The voltage transformer 15 is a terminal box. The standard AC signal is a sinusoidal AC signal with a frequency of 50 Hz.

For example, the potential transformer (PT) in this embodiment is similar to a transformer and is an instrument used to transform voltage. However, the purpose of the transformer to transform voltage is to facilitate the transmission of electrical energy, so the capacity is very large, generally calculated in kilovolt-amperes or megavolt-amperes; while the purpose of the voltage transformer to transform voltage is mainly to power measuring instruments and relay protection devices, to measure the voltage, power and electrical energy of the line, or to protect valuable equipment, motors and transformers in the line when a line fault occurs. Therefore, the capacity of the voltage transformer is very small, generally only a few volt-amperes, tens of volt-amperes, and the maximum does not exceed one thousand volt-amperes. The entry introduces its basic structure, working principle, main types, wiring methods, precautions, abnormalities and handling, and ferromagnetic resonance, etc.

Exemplarily, the voltage transformer in this embodiment can also be a terminal box. The terminal box, also known as a wiring terminal box, is an interface device that switches construction lines, marks branch lines, and provides convenience for wiring and line tracing. In some cases, in order to facilitate construction and debugging, some more special products with more regular installation settings, such as short-circuit isolators, can be installed in the wiring terminal box. The wiring terminal is an accessory product used to achieve electrical connection, which is industrially classified as a connector. With the increasing degree of industrial automation and the increasingly stringent and precise requirements for industrial control, the use of wiring terminals has gradually increased. With the development of the electronics industry, the scope of use of wiring terminals is increasing, and there are more and more types.

Specifically, the voltage transformer is connected to the phase analysis device, the voltage phase analysis device provides a standard AC signal, and at the same time, the phase analysis device receives the inductance change sent by the inductance monitoring device, so that the phase analysis device determines the specific phase information of the discharge in the target metal through the spectrum method according to the phase difference between the inductance change of the inductor coil in different cycles and the standard AC signal, and then determines the discharge phase.

This embodiment can make the determined partial discharge situation more accurate.

In one embodiment, as shown in FIG6 , a partial discharge detection system is provided, which comprises: a discharge detection device 1 and an insulating device to be detected 2; an inductor 11 is arranged opposite to a target metal on which an outer insulating shell of the insulating device to be detected 2 is arranged; when the outer insulating shell of the insulating device to be detected 2 is damaged, eddy currents generated by the target metal change the inductance value of the inductor; an inductance detection device 13 is used to periodically detect the inductance value of the inductor; wherein the inductance value represents the partial discharge condition of the insulating device to be detected.

Specifically, a signal generator is used to apply an AC signal of a certain frequency to the inductor coil, and the inductor coil carrying AC power is brought close to the metal of the switch cabinet, where eddy currents will be generated. The magnetic field generated by the eddy current will reduce the inductance of the inductor coil; when partial discharge occurs, the switch cabinet will vibrate at a certain frequency, thereby changing the distance between the inductor coil and the switch cabinet, which is ultimately reflected in the periodic change of the inductance of the inductor coil; the signal generator in the readout circuit sends a signal to the inductor coil, and then couples the signal coupled to the inductor coil again to achieve wireless transmission, and the signal analyzer analyzes the electrical signal coupled to the readout end; the inductance of the inductor coil is monitored in real time using a digital bridge to reflect the situation of partial discharge. The amplitude of the periodic change of inductance can reflect the degree of partial discharge. The 50Hz AC signal output by the terminal box and the inductance change information are transmitted to the host computer, where the phase of the AC is calculated and compared with the change in the inductance value of the readout coil to obtain the specific phase information of the discharge, and the type of fault is analyzed by the spectrum method.

The above-mentioned partial discharge detection system, discharge detection equipment and insulating equipment to be detected; the inductor coil is arranged opposite to the target metal set on the outer insulating shell of the insulating equipment to be detected; when the outer insulating shell of the insulating equipment to be detected is damaged, the eddy current generated by the target metal changes the inductance value of the inductor coil; the inductance detection device is used to periodically detect the inductance value of the inductor coil; wherein, the inductance value represents the partial discharge condition of the insulating equipment to be detected. The present application determines the partial discharge condition through the mutual inductance effect, and external interference will not affect the mutual inductance effect. Therefore, external interference can be avoided, thereby improving the accuracy of determining the partial discharge condition. The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims (10)

1. The partial discharge detection equipment is characterized by comprising an inductance coil and an inductance detection device;

The inductance coil is connected with the inductance detection device in parallel;

The inductance coil and the target metal arranged on the external insulating shell of the insulating equipment to be detected are oppositely arranged;

Under the condition that an external insulating shell of the insulating equipment to be detected is damaged, eddy current generated by the target metal changes the inductance value of the inductance coil;

the inductance detection device is used for periodically detecting the inductance value of the inductance coil; the inductance value characterizes the partial discharge condition of the insulation equipment to be detected.

2. The apparatus according to claim 1, wherein the inductance monitoring device determines the degree of partial discharge of the insulation apparatus to be detected based on inductance values of the inductance coil at different periods.

3. The apparatus of claim 1, further comprising a signal generator; the signal generator is connected in parallel with the inductance coil and is used for providing alternating current signals for the inductance coil.

4. The apparatus of claim 1, further comprising phase analysis means; the phase analysis device is connected with the inductance monitoring device and is used for determining a discharge phase according to the phase difference between inductance change conditions of the inductance coil in different periods and a standard alternating current signal.

5. The apparatus of claim 4, wherein the standard ac signal is a sinusoidal ac signal having a frequency of 50 Hz.

6. The apparatus of claim 4, further comprising a voltage transformer; the voltage transformer is connected with the phase analysis device and is used for providing a standard alternating current signal for the phase analysis device.

7. The apparatus of claim 6, wherein the voltage transformer is a terminal box.

8. The apparatus according to any one of claims 1 to 7, characterized in that the insulating apparatus to be tested is a gas-insulated switchgear.

9. The apparatus of any one of claims 1 to 7, wherein the inductance detection means is a digital bridge.

10. A partial discharge detection system comprising the discharge detection apparatus according to any one of claims 1 to 9 and an insulating apparatus to be detected;

The inductance coil is arranged opposite to the target metal arranged on the outer insulating shell of the insulating equipment to be detected;

Under the condition that an external insulating shell of the insulating equipment to be detected is damaged, eddy current generated by the target metal changes the inductance value of the inductance coil;

the inductance detection device is used for periodically detecting the inductance value of the inductance coil; the inductance value characterizes the partial discharge condition of the insulation equipment to be detected.