A GIS on-site electric pulse partial discharge charging detection device and detection method

Abstract

This invention discloses a live-line detection device and method for partial discharge in GIS (Gas Insulation System), relating to the field of live-line detection of power equipment. The equivalent capacitance between the primary and secondary windings of a current transformer coil is used as a pulse signal coupling channel. Two sets of pulse current signals within the high-voltage conductor of the GIS are acquired through these two pulse signal coupling channels. Then, the partial discharge voltage signal of a specified frequency is extracted through a pulse partial discharge detection circuit. The two extracted pulse signals are output to a differential mode comparison and acquisition module. This module compares the pulse signals input from the two channels, effectively eliminating interference signals. This invention simultaneously solves two problems in GIS live-line partial discharge pulse detection: pulse coupling and high-voltage side partial discharge interference during live operation. It achieves accurate detection of partial discharge during GIS operation, ensuring the safe and stable operation of GIS electrical equipment.

Description

Technical Field

[0001] This invention relates to the field of application technology of live-line testing of power equipment, specifically to a live-line testing device and method for GIS field electrical pulse partial discharge. Background Technology

[0002] The statements in this section are provided only as background information in connection with this disclosure and may not constitute prior art.

[0003] Gas-insulated metal-enclosed switchgear (GIS) is an essential piece of equipment in the power grid. Its reliability is crucial to the safe and stable operation of the grid. Internal insulation failures in GIS can significantly impact its stable operation. However, defects are unavoidable in the internal insulation of GIS. When GIS is put into operation, these defects can lead to partial discharge (PD) under the influence of an electric field. PD accelerates insulation deterioration and, in severe cases, can cause insulation breakdown. The causes of PD in GIS insulation are twofold: firstly, during manufacturing, transportation, and installation, defects such as bubbles, cracks, burrs, and impurities inevitably appear in the insulation; secondly, under the influence of overvoltage in the power system, these insulation defects can cause PD, accelerating insulation aging and ultimately leading to insulation breakdown. This can cause the entire power system to malfunction or even fail, resulting in significant losses.

[0004] This reveals that partial discharge is not only a phenomenon and characteristic of internal defects and deterioration of insulation, but also an important factor that promotes insulation aging. Therefore, it is necessary to carry out partial discharge detection during GIS operation. However, at present, partial discharge detection during GIS operation is carried out in real time using ultra-high frequency, ultrasonic and ground wave methods. However, the online monitoring devices have poor long-term working stability, cannot make quantitative judgments on the amount of partial discharge, and cannot make accurate assessments of insulation performance. Summary of the Invention

[0005] The purpose of this invention is to address the current lack of effective means for detecting defects in GIS insulation before they develop into faults. This invention provides a device and method for detecting partial discharge on-site via electrical pulses in GIS, resolving issues related to power supply and environmental interference during GIS operation. It also addresses the problem of quantitative detection of partial discharge in GIS, enabling accurate detection of partial discharge during GIS operation, timely identification of internal insulation defects and potential hazards caused by long-term partial discharge, thereby ensuring the safe and stable operation of GIS electrical equipment.

[0006] The technical solution of the present invention is as follows:

[0007] A GIS field electrical pulse partial discharge detection device includes:

[0008] A current transformer, which is used to acquire pulse current signals in the high-voltage conductor of GIS;

[0009] An electrical pulse partial discharge detection circuit is provided, wherein the input terminal of the electrical pulse partial discharge detection circuit is connected to the ground terminal of the current measurement module inside the current transformer, and the output terminal of the electrical pulse partial discharge detection circuit is connected to the signal acquisition module.

[0010] The pulse current signal enters the electrical pulse partial discharge detection circuit through the ground terminal of the current measurement module; the electrical pulse partial discharge detection circuit extracts the partial discharge voltage signal of a specified frequency and outputs the extracted electrical pulse signal to the signal acquisition module for acquisition and detection.

[0011] Furthermore, the equivalent capacitance between the windings of the current transformer coil serves as an electrical pulse signal coupling channel, through which the pulse current signal within the GIS high-voltage conductor is obtained.

[0012] Furthermore, the equivalent capacitance between the primary and secondary windings of the current transformer coil serves as an electrical pulse signal coupling channel, and two sets of pulse current signals within the GIS high-voltage conductor are obtained through the two electrical pulse signal coupling channels.

[0013] The electrical pulse partial discharge detection circuit consists of two sets, and the signal acquisition module is a signal differential mode comparison acquisition module; the signal differential mode comparison acquisition module compares the electrical pulse signals input from the two input channels and effectively eliminates interference signals;

[0014] The input terminals of the two sets of electrical pulse partial discharge detection circuits are connected to the ground terminals of the current measurement modules corresponding to the primary winding and the secondary winding, respectively, and the output terminals of the two sets of electrical pulse partial discharge detection circuits are connected to the two input channels of the signal differential mode comparison and acquisition module, respectively.

[0015] Furthermore, the signal differential mode comparison acquisition module does not record electrical pulse signals with a voltage difference of less than 10% between the two input channels, but records electrical pulse signals with a voltage difference of more than 10% between the two input channels.

[0016] Furthermore, the electrical pulse partial discharge detection circuit includes:

[0017] The frequency selection circuit extracts the partial discharge voltage signal at a frequency of 200 kHz to 1 MHz.

[0018] Furthermore, the electrical pulse partial discharge detection circuit further includes:

[0019] The signal amplification circuit uses an adjustable amplification factor of 20 to 500 times to amplify the extracted electrical pulse signal and output the amplified electrical pulse signal to the signal acquisition module for acquisition and detection.

[0020] Furthermore, the electrical pulse partial discharge detection circuit further includes:

[0021] The clamping circuit controls the voltage across the frequency selection circuit to be above 1V, ensuring reliable grounding of the current measurement module's grounding terminal and allowing the pulse current signal to enter the frequency selection circuit.

[0022] Furthermore, the electrical pulse partial discharge detection circuit further includes:

[0023] A protective ball gap is provided, with its voltage set at 100V to prevent malfunctions in the electrical pulse partial discharge detection circuit.

[0024] A method for detecting partial discharge charge in GIS field using electrical pulses, based on the aforementioned device for detecting partial discharge charge in GIS field using electrical pulses, includes:

[0025] Step S1: Obtain the pulse current signal in the GIS high-voltage conductor through a current transformer;

[0026] Step S2: The pulse current signal is fed into the electrical pulse partial discharge detection circuit through the grounding terminal of the current measurement module;

[0027] Step S3: Extract the partial discharge voltage signal of the specified frequency through the electrical pulse partial discharge detection circuit, and output the extracted electrical pulse signal to the signal acquisition module for acquisition and detection.

[0028] Further, step S1 includes:

[0029] The equivalent capacitance between the primary and secondary windings of the current transformer coil is used as an electrical pulse signal coupling channel, and two sets of pulse current signals in the GIS high-voltage conductor are obtained through the two electrical pulse signal coupling channels.

[0030] Step S2 includes:

[0031] Two sets of pulse current signals enter a set of electrical pulse partial discharge detection circuits through the grounding terminal of the current measurement module;

[0032] Step S3 includes:

[0033] Based on two sets of pulse current signals, the partial discharge voltage signals with a frequency of 200k to 1MHz are extracted through the corresponding pulse partial discharge detection circuits, and the extracted two sets of pulse signals are output to the two input channels of the signal differential mode comparison and acquisition module. The signal differential mode comparison and acquisition module compares the pulse signals input to the two input channels to effectively eliminate interference signals.

[0034] The signal differential mode comparison acquisition module does not record electrical pulse signals with a voltage difference of less than 10% between the two input channels, but records electrical pulse signals with a voltage difference of more than 10% between the two input channels.

[0035] Compared with existing technologies, the advantages of this invention are:

[0036] 1. A device and method for detecting live partial discharge in GIS using electrical pulses, comprising: a current transformer for acquiring pulse current signals within the high-voltage conductor of the GIS; and an electrical pulse partial discharge detection circuit, wherein the input terminal of the detection circuit is connected to the grounding terminal of a current measurement module inside the current transformer, and the output terminal of the detection circuit is connected to a signal acquisition module; the pulse current signal enters the electrical pulse partial discharge detection circuit through the grounding terminal of the current measurement module; the detection circuit extracts a partial discharge voltage signal of a specified frequency and outputs the extracted electrical pulse signal to the signal acquisition module for acquisition and detection; it uses the equivalent capacitance between the windings of the current transformer coil as the electrical pulse signal coupling channel, and acquires the pulse current signal within the high-voltage conductor of the GIS through the electrical pulse signal coupling channel, thus solving the electrical pulse coupling problem faced in the detection of live partial discharge pulses in GIS.

[0037] 2. A device and method for detecting partial discharge on-site in GIS using electrical pulses, wherein the equivalent capacitance between the primary and secondary windings of a current transformer coil is used as an electrical pulse signal coupling channel. Two sets of pulse current signals are obtained from the high-voltage conductor of the GIS through the two electrical pulse signal coupling channels. Then, the partial discharge voltage signal of a specified frequency is extracted through a separate electrical pulse partial discharge detection circuit. The two extracted electrical pulse signals are output to a signal differential mode comparison and acquisition module. At the same time, the signal differential mode comparison and acquisition module compares the electrical pulse signals input from the two input channels to effectively eliminate interference signals, thereby eliminating high-voltage side partial discharge interference. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of a GIS field electrical pulse partial discharge detection device. Detailed Implementation

[0039] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0040] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0041] Example 1

[0042] Partial discharge in GIS is not only a phenomenon and characteristic of internal insulation defects and deterioration, but also an important factor that promotes insulation aging. Therefore, it is necessary to carry out partial discharge detection during GIS operation. However, at present, partial discharge detection during GIS operation is carried out in real time using ultra-high frequency, ultrasonic and ground wave methods. However, the online monitoring devices have poor long-term working stability, cannot make quantitative judgments on the amount of partial discharge, and cannot make accurate assessments of insulation performance.

[0043] Therefore, based on the above-mentioned problems, this embodiment proposes a field electrical pulse partial discharge detection device and method for GIS, which solves the problems of power supply and environmental interference in GIS operation; solves the problem of quantitative detection of partial discharge in GIS, realizes accurate detection of partial discharge during GIS operation, and timely detects internal insulation defects and hidden dangers caused by long-term partial discharge, so as to ensure the safe and stable operation of GIS electrical equipment.

[0044] Please see Figure 1 A GIS field electrical pulse partial discharge detection device, specifically comprising:

[0045] A current transformer (CT) is used to acquire pulse current signals within the high-voltage conductor of a GIS. It should be noted that in this embodiment, only the current transformer is used to acquire the pulse current signal, and the structure of the current transformer itself is not modified. Therefore, the current measurement module inside the current transformer measures the current amplitude and phase without being affected by the added electrical pulse partial discharge detection circuit. Thus, it can be concluded that the function of the current transformer in this embodiment is different from the function of the current transformer itself (converting large currents into small currents for detection, etc.).

[0046] Preferably, the equivalent capacitance between the windings of the current transformer coil serves as an electrical pulse signal coupling channel, through which the pulse current signal in the GIS high-voltage conductor is obtained;

[0047] An electrical pulse partial discharge detection circuit is provided, wherein the input terminal of the electrical pulse partial discharge detection circuit is connected to the ground terminal of the current measurement module inside the current transformer, and the output terminal of the electrical pulse partial discharge detection circuit is connected to the signal acquisition module.

[0048] The pulse current signal enters the electrical pulse partial discharge detection circuit through the ground terminal of the current measurement module; the electrical pulse partial discharge detection circuit extracts the partial discharge voltage signal of a specified frequency and outputs the extracted electrical pulse signal to the signal acquisition module for acquisition and detection.

[0049] In this embodiment, the detection of partial discharge pulses on a live GIS mainly faces two problems: electrical pulse coupling and interference from high-voltage side partial discharge during live operation. The problem of electrical pulse coupling is solved by using the equivalent capacitance between the windings of the current transformer coil as the electrical pulse signal coupling channel. The problem of interference from high-voltage side partial discharge during live operation is solved through the following structural design.

[0050] In this embodiment, specifically, the equivalent capacitance between the primary and secondary windings of the current transformer coil serves as an electrical pulse signal coupling channel, and two sets of pulse current signals within the GIS high-voltage conductor are obtained through the two electrical pulse signal coupling channels. Preferably, the current transformer typically has two or more secondary coils for measurement and protection. In this embodiment, to ensure the effectiveness of the signal differential mode comparison acquisition module output, it is more appropriate to select two protection coils for the two coils of the current transformer.

[0051] The electrical pulse partial discharge detection circuit consists of two sets, and the signal acquisition module is a signal differential mode comparison acquisition module. The signal differential mode comparison acquisition module compares the electrical pulse signals input from the two input channels and effectively eliminates interference signals. Preferably, the interference signals include corona discharge during high-voltage side operation, etc. The signal differential mode comparison acquisition module adopts a maximum sampling rate of 5M S / s and a maximum sampling depth of 16MB.

[0052] The input terminals of the two sets of electrical pulse partial discharge detection circuits are connected to the ground terminals of the current measurement modules corresponding to the primary winding and the secondary winding, respectively, and the output terminals of the two sets of electrical pulse partial discharge detection circuits are connected to the two input channels of the signal differential mode comparison and acquisition module, respectively.

[0053] In this embodiment, specifically, the signal differential mode comparison acquisition module does not record electrical pulse signals with a voltage difference of less than 10% between the two input channels, but records electrical pulse signals with a voltage difference of more than 10% between the two input channels; that is, the signal differential mode comparison acquisition module uses 10% of the amplitude of the single-channel sampled electrical pulse voltage as a threshold, and does not record electrical pulse signals with a voltage difference of less than 10% between the two input channels.

[0054] In this embodiment, specifically, the electrical pulse partial discharge detection circuit includes:

[0055] The frequency selection circuit extracts the partial discharge voltage signal at a frequency of 200 kHz to 1 MHz.

[0056] In this embodiment, specifically, the electrical pulse partial discharge detection circuit further includes:

[0057] The signal amplification circuit uses an adjustable amplification factor of 20 to 500 times to amplify the extracted electrical pulse signal and output the amplified electrical pulse signal to the signal acquisition module (i.e., the signal differential mode comparison acquisition module) for acquisition and detection.

[0058] In this embodiment, specifically, the electrical pulse partial discharge detection circuit further includes:

[0059] The clamping circuit controls the voltage across the frequency selection circuit to be above 1V, ensuring reliable grounding of the current measurement module's grounding terminal and allowing the pulse current signal to enter the frequency selection circuit.

[0060] In this embodiment, specifically, the electrical pulse partial discharge detection circuit further includes:

[0061] A protective ball gap is provided, with its voltage set at 100V to prevent malfunctions in the electrical pulse partial discharge detection circuit.

[0062] This embodiment, based on the aforementioned GIS field electrical pulse partial discharge charging detection device, proposes a method for GIS field electrical pulse partial discharge charging detection, specifically including:

[0063] Step S1: Obtain the pulse current signal in the GIS high-voltage conductor through a current transformer;

[0064] Step S2: The pulse current signal is fed into the electrical pulse partial discharge detection circuit through the grounding terminal of the current measurement module;

[0065] Step S3: Extract the partial discharge voltage signal of the specified frequency through the electrical pulse partial discharge detection circuit, and output the extracted electrical pulse signal to the signal acquisition module for acquisition and detection.

[0066] In this embodiment, specifically, step S1 includes:

[0067] The equivalent capacitance between the primary and secondary windings of the current transformer coil is used as an electrical pulse signal coupling channel, and two sets of pulse current signals in the GIS high-voltage conductor are obtained through the two electrical pulse signal coupling channels.

[0068] Step S2 includes:

[0069] Two sets of pulse current signals enter a set of electrical pulse partial discharge detection circuits through the grounding terminal of the current measurement module;

[0070] Step S3 includes:

[0071] Based on two sets of pulse current signals, the partial discharge voltage signals with a frequency of 200k to 1MHz are extracted through the corresponding pulse partial discharge detection circuits, and the extracted two sets of pulse signals are output to the two input channels of the signal differential mode comparison and acquisition module. The signal differential mode comparison and acquisition module compares the pulse signals input to the two input channels to effectively eliminate interference signals.

[0072] The signal differential mode comparison acquisition module does not record electrical pulse signals with a voltage difference of less than 10% between the two input channels, but records electrical pulse signals with a voltage difference of more than 10% between the two input channels.

[0073] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

[0074] This background section is provided to generally present the context of the invention. The work of the currently named inventors, the work to the extent described in this background section, and aspects of this section that did not constitute prior art at the time of application are neither expressly nor impliedly acknowledged as prior art to the invention.

Claims

1. A GIS field electrical pulse partial discharge detection device, characterized in that, include: A current transformer, which is used to acquire pulse current signals in the high-voltage conductor of GIS; An electrical pulse partial discharge detection circuit is provided, wherein the input terminal of the electrical pulse partial discharge detection circuit is connected to the ground terminal of the current measurement module inside the current transformer, and the output terminal of the electrical pulse partial discharge detection circuit is connected to the signal acquisition module. The pulse current signal enters the electrical pulse partial discharge detection circuit through the ground terminal of the current measurement module; the electrical pulse partial discharge detection circuit extracts the partial discharge voltage signal of a specified frequency and outputs the extracted electrical pulse signal to the signal acquisition module for acquisition and detection; The equivalent capacitance between the primary and secondary windings of the current transformer coil serves as an electrical pulse signal coupling channel, and two sets of pulse current signals in the GIS high-voltage conductor are obtained through the two electrical pulse signal coupling channels. The electrical pulse partial discharge detection circuit consists of two sets, and the signal acquisition module is a signal differential mode comparison acquisition module. The signal differential mode comparison acquisition module compares the electrical pulse signals input from the two input channels and effectively eliminates interference signals.

2. The GIS field electrical pulse partial discharge detection device according to claim 1, characterized in that, The equivalent capacitance between the windings of the current transformer coil serves as a coupling channel for electrical pulse signals, through which pulse current signals within the GIS high-voltage conductor are obtained.

3. The GIS field electrical pulse partial discharge detection device according to claim 2, characterized in that, The input terminals of the two sets of electrical pulse partial discharge detection circuits are connected to the ground terminals of the current measurement modules corresponding to the primary winding and the secondary winding, respectively, and the output terminals of the two sets of electrical pulse partial discharge detection circuits are connected to the two input channels of the signal differential mode comparison and acquisition module, respectively.

4. The GIS field electrical pulse partial discharge detection device according to claim 3, characterized in that, The signal differential mode comparison acquisition module does not record electrical pulse signals with a voltage difference of less than 10% between the two input channels, but records electrical pulse signals with a voltage difference of more than 10% between the two input channels.

5. The GIS field electrical pulse partial discharge detection device according to claim 1, characterized in that, The electrical pulse partial discharge detection circuit includes: The frequency selection circuit extracts the partial discharge voltage signal at a frequency of 200 kHz to 1 MHz.

6. The GIS field electrical pulse partial discharge detection device according to claim 5, characterized in that, The electrical pulse partial discharge detection circuit further includes: The signal amplification circuit uses an adjustable amplification factor of 20 to 500 times to amplify the extracted electrical pulse signal and output the amplified electrical pulse signal to the signal acquisition module for acquisition and detection.

7. The GIS field electrical pulse partial discharge detection device according to claim 5, characterized in that, The electrical pulse partial discharge detection circuit further includes: The clamping circuit controls the voltage across the frequency selection circuit to be above 1V, ensuring reliable grounding of the current measurement module's grounding terminal and allowing the pulse current signal to enter the frequency selection circuit.

8. The GIS field electrical pulse partial discharge detection device according to claim 5, characterized in that, The electrical pulse partial discharge detection circuit further includes: A protective ball gap is provided, with its voltage set at 100V to prevent malfunctions in the electrical pulse partial discharge detection circuit.

9. A method for detecting partial discharge charge in GIS field using electrical pulses, characterized in that, A GIS field electrical pulse partial discharge detection device according to any one of claims 1-8 includes: Step S1: Obtain the pulse current signal in the GIS high-voltage conductor through a current transformer; Step S2: The pulse current signal is fed into the electrical pulse partial discharge detection circuit through the grounding terminal of the current measurement module; Step S3: Extract the partial discharge voltage signal of a specified frequency through the electrical pulse partial discharge detection circuit, and output the extracted electrical pulse signal to the signal acquisition module for acquisition and detection.

10. A method for detecting partial discharge in GIS field according to claim 9, characterized in that, Step S1 includes: The equivalent capacitance between the primary and secondary windings of the current transformer coil is used as an electrical pulse signal coupling channel. Two sets of pulse current signals in the GIS high-voltage conductor are obtained through the two electrical pulse signal coupling channels. Step S2 includes: Two sets of pulse current signals enter a set of electrical pulse partial discharge detection circuits through the grounding terminal of the current measurement module; Step S3 includes: Based on two sets of pulse current signals, the partial discharge voltage signals with a frequency of 200k~1MHz are extracted through the corresponding pulse partial discharge detection circuits, and the extracted two sets of pulse signals are output to the two input channels of the signal differential mode comparison and acquisition module. The signal differential mode comparison and acquisition module compares the pulse signals input to the two input channels to effectively eliminate interference signals. The signal differential mode comparison acquisition module does not record electrical pulse signals with a voltage difference of less than 10% between the two input channels, but records electrical pulse signals with a voltage difference of more than 10% between the two input channels.

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