Transient waveform acquisition and analysis method between different grounding systems based on conduction coupling

Abstract

The invention discloses a transient test and analysis method for providing conduction coupling leading under different grounding conditions, and the method comprises the steps: 1, carrying out the switching operation through an operation wave impact test system device and a high-voltage isolation probe of a high-voltage test room, systematically carrying out the switching-on and switching-off operation of a first-stage switch and a front switch, and carrying out the switching-on and switching-off operation of a second-stage switch and a front switch; recording waveform data captured by the oscilloscope during instantaneous operation; and 2, considering near-end grounding and far-end grounding modes, respectively acquiring waveform data between the operation wave impact test system equipment and the equipment ground wire during near-end grounding and far-end grounding, and pressurizing the operation wave impact test system at the moment. According to the method for collecting and analyzing the transient waveforms between the different grounding systems based on conduction coupling, the transient waveform characteristics under different grounding conditions are systematically arranged and analyzed, and reference is provided for voltage withstanding protection research of the grounding systems.

Description

Technical Field

[0001] The present invention relates to the technical field of transient testing of conductive coupling in power systems, and in particular to a method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling. Background Art

[0002] Currently, there is no systematic method for transient testing of ground potential differences between different substation grounding systems. Switching operations are generally studied only for certain types of switches, such as GIS disconnectors and IGBT switches. During testing, disturbance voltages are collected from certain equipment in the secondary system, but there is a lack of testing across different grounding systems. While recent literature has explained the causes of zero-ground potential differences and proposed methods for mitigating them in lightning protection and equipment grounding systems, no specific analysis of the waveform characteristics of zero-ground disturbance voltages has been conducted. Similarly, analysis of the impact of grounding methods on transients is common, with single-phase and high-resistance grounding being analyzed, while research on near-end and far-end grounding is limited. Conductive coupling, which is dominant in low-frequency components and presents as differential-mode interference, can harm signal transmission and directly impact equipment operation. Conductive coupling between different grounding systems is quite strong and highly detrimental. Summary of the Invention

[0003] In order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling, which meets the measurement requirements of transient oscillation waves, designs test methods for different grounding systems, creatively uses mathematical integration methods to calculate the discharge amount, analyzes the transient waveform characteristics between different grounding systems based on the discharge amount and spectrum, and uses analysis software to facilitate induction and a clearer understanding of the entire test process.

[0004] The present invention is achieved through the following technical solutions:

[0005] A method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling includes the following steps:

[0006] Step S1: Using the operating wave shock test system equipment and high-voltage isolation probe in the high-voltage test laboratory, perform switch operations, systematically close and open the primary switch and the front switch, and record the discharge waveform data captured by the oscilloscope during the instantaneous operation;

[0007] Step S2: Considering the proximal grounding and distal grounding modes, waveform data between the operational wave shock test system equipment and the equipment ground wire are collected when the proximal grounding and distal grounding are respectively used. At this time, the operational wave shock test system is pressurized.

[0008] Step S3: Integrate the collected discharge waveform through software processing to obtain discharge capacity data;

[0009] Step S4: Perform FFT transformation on the discharge waveform and perform spectrum analysis.

[0010] Step 1 is specifically implemented as follows:

[0011] Step S1.1: The operating wave shock test system equipment in the high-voltage laboratory is a primary switch, which is closed and opened in sequence, and is operated once every one minute;

[0012] Step S1.2: The operation wave shock test system equipment in the high-voltage laboratory is a front switch, which is operated in the order of closing and opening, and is operated once every one minute.

[0013] Step 2 is specifically implemented as follows:

[0014] Step S2.1: When the proximal grounding is performed, the ground wire of the operating wave shock test system equipment is used as the low-voltage ground, and the ground wire of the operating wave shock test system equipment is used as the high-voltage ground;

[0015] Step S2.2: When remote grounding is performed, the ground wire of the operating wave shock test system equipment is used as the low-voltage ground, and the ground wire of the operating wave shock test system equipment is used as the high-voltage ground (the distance between the ground wire of the operating wave shock test system and the ground wire is 25m).

[0016] Step 3 is specifically implemented as follows:

[0017] Step S3.1: Select one of the following integration methods: mathematical area of ​​oscillation wave, mathematical area of ​​the same coordinate, absolute area of ​​oscillation wave, and absolute area of ​​all discharge waveforms for integration.

[0018] Step 4 is specifically implemented as follows:

[0019] Step S4.1: The software performs FFT root mean square normalization on the acquired waveform, and verifies through spectrum analysis that the transient characteristics are attributed to the conduction coupling mode.

[0020] A method for implementing a transient waveform acquisition and analysis method between different grounding systems based on conductive coupling, comprising an oscilloscope, a high-voltage isolation probe, an operating wave impact test system device, and an operating wave impact test system pressurization method, wherein:

[0021] Oscilloscopes and high-voltage isolation probes are important waveform acquisition tools;

[0022] The operating wave shock test system equipment acts as a primary switch, and the operating wave shock test system equipment acts as a pre-switch, providing operating interference transient data for the overall test;

[0023] The pressurization method of the operating wave impact test system provides test conditions for measuring transient waveforms between high-voltage ground and low-voltage ground under different grounding conditions.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] Existing transient ground potential difference tests are limited to a single device and there is little research on the waveform characteristics of the ground potential difference between different grounding systems. The method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling provided by the present invention uses the first-level switch and the front switch of the high-voltage laboratory operation wave impact test system equipment to perform a system ground switch operation test, collects the interference voltage between the equipment ground wire and the 220V neutral line, and explores the interference voltage between the high-voltage ground wire and the low-voltage ground wire when pressurized under the two grounding methods of proximal grounding and distal grounding. The testing method is simpler. The present invention pioneered an integral method to analyze the transient operation discharge amount. When analyzing, the FFT method and the discharge amount are combined to comprehensively illustrate the harmfulness of the transient operation, which is more convincing than the existing research methods. The test and analysis method provided by the present invention has important reference significance in the transient aspect dominated by conductive coupling, and at the same time fills the gap in the field of transient test and analysis between different grounding systems based on conductive coupling. The test and analysis method provided by the present invention can better realize partial discharge fault monitoring with higher efficiency, provide more reliable data analysis for equipment status maintenance, and provide a more accurate research method for grounding system withstand voltage protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a test circuit diagram for switch testing, which uses a test transformer to simulate the circuit load process during the actual opening and closing operations of the line switch in operation.

[0027] Figure 2 This is the impact diagram of the closing and opening operations of the first-level switch, recording the more typical representatives during the operation process.

[0028] Figure 3 For the proximal and distal operation shock diagrams, the oscillation wave decays rapidly and the peak value of the waveform reaches the kV level.

[0029] Figure 4 This is the discharge amount generated from zero to ground under the primary switching operation. The discharge amount obtained by integration under the same operation is relatively close.

[0030] Figure 5 Normalized RMS amplitude spectrum of the pre-switch opening, with the frequencies with higher amplitudes marked. DETAILED DESCRIPTION

[0031] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are provided as examples only, and those skilled in the art may derive variations based on these methods. The basic principles of the present invention defined in the following description may be applied to equivalents and similar embodiments of the present invention.

[0032] Among them, the technical solution adopted by the present invention is: dividing the switch operating system into a first-level switch and a front switch, using the operation wave impact test system equipment as the first-level switch, and the operation wave impact test system equipment as the front switch, directly performing the switch closing and opening operations, collecting the interference voltage between the equipment ground wire and the 220V neutral wire, and designing the operation wave impact test system pressurization method, collecting the interference voltage between the operation wave impact test system equipment and the operation wave impact test system equipment when the proximal grounding and the distal grounding are respectively performed, and saving the signal data obtained from the test as a CSV format file, using analysis software to perform integral calculation and FFT transformation on the signal data, which is convenient for summarization and a clearer understanding of the entire process of the entire test.

[0033] For details, see the attached drawings. Figure 1 , Figure 1 This is a circuit diagram for the switch test circuit of the present invention. In this circuit, each device in the test system is simplified to a capacitor (power supply capacitor, load capacitor, etc.). The primary switch serves as the master switch for the front-end equipment in the control room. Its closing and opening operations involve transient processes, which have a certain impact on the time characteristics of the potential. The pre-switch, acting as a secondary switch, is less harmful than the interference voltage generated by the primary switch.

[0034] Figure 2 This is the impact diagram of the closing and opening operation of the first-level switch of the present invention. In the figure, when the first-level switch is operating, the ground potential difference when the switch is open is higher than the ground potential difference generated when the switch is closed. The waveform is composed of several oscillation waves with uncertain frequencies. An oscillation wave generally has 3 or 4 cycles, and the waveform frequency composition is complex. In addition, Figure 2 As shown in (a) and (b), the high value of the closing waveform is between 17V and 38V, and about three oscillation waves with decreasing peak values ​​are generated at the moment of closing. The period between the primary and secondary oscillation waves is about 0.3ms. Figure 2 Figures (c) and (d) show the waveforms generated by the tripping operation, with the high value ranging from 42V to 142V. Approximately six or seven oscillations are generated at the moment of tripping, which decay to zero after approximately 1ms. These results indicate that a greater discharge may occur at the moment of tripping.

[0035] Figure 3 This is a diagram of the impact of the near-end and far-end operations of the present invention. The transient ground potential difference generated by the near-end ground in the diagram typically consists of a main oscillation wave that decays into a relatively stable frequency of small oscillation waves after about 0.1ms. The number of small oscillation waves is about 18. The transient ground potential difference generated by the far-end ground is higher than that generated by the near-end ground.

[0036] Figure 4The discharge amount generated by the zero-ground under the first-level switch operation of the present invention is close to the discharge amount of the 5 closing operations. The discharge amount of the second opening operation is 6 times the average value, showing that the closing operation waveform is more stable. The discharge amount generated by the opening operation is about 3 times that of the closing operation. This result is consistent with the Figure 2 This corresponds to the phenomenon of a large number of discharge pulses and a high peak voltage during the center opening operation.

[0037] Figure 5 This is the normalized RMS amplitude spectrum of the pre-switch opening operation of the present invention. It can be seen that the main frequency is within 100 kHz (with higher amplitudes at frequencies such as 61 kHz and 78 kHz), and there are also certain high-frequency components, indicating that the interference voltage generated by the pre-switch closing operation is dominated by conductive coupling.

[0038] In the preferred embodiment of the present invention, those skilled in the art should note that the operational wave shock test system equipment, analysis software, etc. involved in the present invention can be regarded as prior art.

[0039] Preferred embodiment.

[0040] The present invention discloses a transient waveform acquisition method and a waveform analysis method between different grounding systems based on conductive coupling, comprising the following steps:

[0041] Step S1: Using the operating wave shock test system equipment and high-voltage isolation probe in the high-voltage test laboratory, perform switch operations, systematically close and open the primary switch and the front switch, and record the waveform data captured by the oscilloscope during the instantaneous operation;

[0042] Step S2: Considering the proximal grounding and distal grounding modes, waveform data between the operating wave shock test system equipment and the ground wire of the operating wave shock test system equipment are collected respectively when the proximal grounding and distal grounding are used. At this time, the operating wave shock test system is pressurized.

[0043] Step S3: Integrate the collected waveform through software processing to obtain discharge data;

[0044] Step S4: Perform FFT transformation on the waveform and perform spectrum analysis.

[0045] Wherein step S1 is specifically implemented as follows:

[0046] Step S1.1: The operating wave shock test system equipment in the high-voltage laboratory is a primary switch, which is operated in the order of closing and opening, and is operated once every one minute;

[0047] Step S1.2: The operation wave shock test system equipment in the high-voltage laboratory is a front switch, which is operated in the order of closing and opening, and is operated once every one minute.

[0048] Specifically, step S2 is implemented as follows:

[0049] Step S2.1: When the proximal grounding is performed, the ground wire of the operating wave shock test system equipment is used as the low-voltage ground, and the ground wire of the operating wave shock test system equipment is used as the high-voltage ground;

[0050] Step S2.2: When remote grounding is performed, the ground wire of the operating wave shock test system equipment is used as the low-voltage ground, and the ground wire of the operating wave shock test system equipment is used as the high-voltage ground (the distance between the ground wire of the operating wave shock test system and the ground wire is 25m).

[0051] In particular, step S3 is specifically implemented as the following steps:

[0052] Step S3.1: Select one of the following integration methods: oscillation wave mathematical area, same-coordinate mathematical area, oscillation wave absolute area, and total x absolute area.

[0053] In addition, step S4 is specifically implemented as the following steps:

[0054] Step S4.1: The software performs FFT root mean square normalization on the acquired waveform, and verifies through spectrum analysis that the transient characteristics are attributed to the conduction coupling mode.

[0055] The present invention discloses a method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling, which is characterized by comprising an oscilloscope, a high-voltage isolation probe, an operating wave impact test system, and a pressurization method for the operating wave impact test system, wherein:

[0056] Oscilloscopes and high-voltage isolation probes are important waveform acquisition tools;

[0057] The operating wave shock test system equipment acts as a primary switch, and the operating wave shock test system equipment acts as a pre-switch, providing operating interference transient data for the overall test;

[0058] The pressurization method of the operating wave impact test system provides test conditions for measuring transient waveforms between high-voltage ground and low-voltage ground under different grounding conditions.

[0059] Specifically, the switch operation interference data mainly includes instantaneous waveform signal data generated by switch closing and switch opening.

[0060] More specifically, the high voltage ground and the low voltage ground are equipment grounding.

[0061] Preferably, the test device consists of: This test mainly consists of the operating wave shock test system equipment of the high-voltage test room and the operating wave shock test system equipment.

[0062] 1. Operational wave shock test system equipment: As the master control equipment of the high-voltage test room, it has different switches, mainly primary switches, which can provide switch operation transient testing.

[0063] 2. Operational wave shock test system equipment: As a test equipment for near-end and far-end ground, the grounding wire is led to the grounding pile to provide a low-voltage ground.

[0064] 3. Operational wave shock test system equipment: As the test equipment for the near-end ground and the far-end ground, it is protected by grounding and provides a high-voltage ground.

[0065] 4. Tektronix DPO3012B Oscilloscope: 100MHz bandwidth, USB connectivity for convenient data storage, and FilterVu™ low-pass filtering to remove low-peak background noise and obtain a true signal with minimal background interference.

[0066] In particular, waveform analysis uses analysis software, and integration methods include oscillation wave mathematical area, same-coordinate mathematical area, oscillation wave absolute area, and total x absolute area. Select one of these methods for integration.

[0067] It is important to note that spectrum analysis uses the x-axis time interval as an important sampling parameter, and different time intervals produce different amplitude interval values.

[0068] The beneficial effect of the present invention is to design a simpler test method, filling the gap in the field of transient testing between different grounding systems based on conductive coupling.

[0069] The present invention provides a method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling. The method uses the primary switch and the front switch of the high-voltage laboratory operation wave impact test system equipment to perform a system ground switch operation test, collects the interference voltage between the equipment ground wire and the 220V neutral line, and explores the interference voltage between the high-voltage ground wire and the low-voltage ground wire when pressurized under the two grounding methods of proximal grounding and distal grounding. The testing method is simpler. The present invention pioneered an integral method to analyze the transient operation discharge. During the analysis, the FFT method and the discharge amount are combined to comprehensively illustrate the harmfulness of the transient operation, which is more convincing than the existing research methods. The test and analysis method provided by the present invention has important reference significance in the transient aspect dominated by conductive coupling, and at the same time fills the gap in the field of transient test and analysis between different grounding systems based on conductive coupling. The test and analysis method provided by the present invention can better realize partial discharge fault monitoring with higher efficiency, provide more reliable data analysis for equipment status maintenance, and provide a more accurate research method for grounding system withstand voltage protection.

[0070] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling, characterized in that: The following steps are involved: Step S1: Using the operating wave shock test system equipment and high-voltage isolation probe in the high-voltage test laboratory, perform switch operations, systematically close and open the primary switch and the front switch, and record the discharge waveform data captured by the oscilloscope during the instantaneous operation; Step S2: Considering the proximal grounding and distal grounding modes, waveform data between the operational wave shock test system equipment and the equipment ground wire are collected respectively when the proximal grounding and distal grounding are used. At this time, the operational wave shock test system is pressurized. Step S3: Integrate the collected discharge waveform through software processing to obtain discharge capacity data; Step S4: Perform FFT transformation on the discharge waveform and perform spectrum analysis.

2. The method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling according to claim 1, characterized in that: Step 1 is specifically implemented as follows: Step S1.1: The operating wave shock test system equipment in the high-voltage laboratory is a primary switch, which is closed and opened in sequence, and is operated once every one minute; Step S1.2: The operation wave shock test system equipment in the high-voltage laboratory is a front switch, which is operated in the order of closing and opening, and is operated once every one minute.

3. The method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling according to claim 2, characterized in that: Step 2 is specifically implemented as follows: Step S2.1: When the proximal grounding is performed, the ground wire of the operating wave shock test system equipment is used as the low-voltage ground, and the ground wire of the operating wave shock test system equipment is used as the high-voltage ground; Step S2.2: When remote grounding is performed, the ground wire of the operating wave shock test system equipment is used as the low-voltage ground, and the ground wire of the operating wave shock test system equipment is used as the high-voltage ground (the distance between the ground wire of the operating wave shock test system and the ground wire is 25m).

4. The method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling according to claim 3 is characterized in that: Step 3 is specifically implemented as follows: Step S3.1: Select one of the following integration methods: mathematical area of ​​oscillation wave, mathematical area of ​​the same coordinate, absolute area of ​​oscillation wave, and absolute area of ​​all discharge waveforms for integration.

5. The method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling according to claim 4 is characterized in that: Step 4 is specifically implemented as follows: Step S4.1: The software performs FFT root mean square normalization on the acquired waveform, and verifies through spectrum analysis that the transient characteristics are attributed to the conduction coupling mode.

6. A method for implementing the method for collecting and analyzing transient waveforms between different grounding systems based on conductive coupling according to any one of claims 1 to 5, characterized in that: It includes an oscilloscope, a high-voltage isolation probe, an operating wave shock test system device, a pressurization method for the operating wave shock test system device, and an analysis module, wherein: Oscilloscopes and high-voltage isolation probes are important waveform acquisition tools; The operating wave shock test system equipment acts as a primary switch, and the operating wave shock test system equipment acts as a pre-switch, providing operating interference transient data for the overall test; The pressure equipment method of the operating wave impact test system provides test conditions for measuring transient waveforms between high-voltage ground and low-voltage ground under different grounding conditions; The analysis module is the task carrier for FFT processing and integral analysis of transient waveforms.

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