Simulation device and method for spatial-temporal distribution characteristics of multi-parameter signals of internal discharge defects of large transformer
By designing the equivalent experimental device of large transformer and the equivalent position monitoring device of multiple inlet/outline lines, the problem of neglecting internal structure influence and single sensor arrangement in the existing technology is solved, and the spatiotemporal distribution of multi-parameter signals for internal discharge defects of large transformers is realized. Accurate monitoring of features provides a reliable basis for active protection of large transformers.
Patent Information
- Application Number
- CN202411430781.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2025-01-07
AI Technical Summary
When the prior art studies the spatial and temporal distribution characteristics of multi-parameter signals of internal discharge defects in large transformers, it ignores the influence of the internal structure of the transformer on signal propagation, and the sensor arrangement is single, so the timing characteristics and spatial propagation laws of the discharge signal cannot be accurately obtained.
A simulation device including a large transformer equivalent experimental device and a multi-in/outline equivalent position monitoring device is designed to simulate the internal environment of the transformer through an epoxy barrel, an inter-turn discharge model, a multi-channel high-frequency current sensor and an ultrasonic sensor. , realize simultaneous monitoring at different locations and analyze the spatiotemporal distribution characteristics of multi-parameter signals.
It effectively solves the problem of unclear signal propagation laws caused by the differences between the model and the actual situation, and realizes accurate monitoring of the space-time distribution of multi-parameter signals of internal discharge defects of large transformers, providing a reliable basis for active protection and early warning.
Smart Images
Figure CN119269988A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of electrical equipment measurement, and in particular relates to a device and method for simulating the temporal and spatial distribution characteristics of multi-parameter signals of internal discharge defects of a large transformer. Background Art
[0002] As an irreplaceable key link in the new power system, the health status of the transformer greatly affects the safe and reliable operation of the entire power grid. How to ensure the long-term stable operation of transformer equipment has always been the core content of the operation and management of power grid equipment. In recent years, the annual capacity of new transformers in my country has increased rapidly, but at the same time, the frequency of transformer failures has also increased. Large transformers are subject to various overvoltage shocks, thermal and mechanical effects during operation, and the complex and harsh operating environment greatly increases the probability of failure. Relevant statistics show that the incidence of faults caused by internal discharge defects in large transformers is as high as 60% to 70% of the total faults. Therefore, clarifying the propagation law of characteristic signals during the development of internal discharge defects in large transformers and realizing reliable monitoring of characteristic parameters are one of the key issues currently facing the field of transformer online monitoring.
[0003] In the prior art, there are two deficiencies in the research of multi-parameter signal propagation characteristics of the inter-turn discharge development process of large transformers by domestic and foreign researchers. First, in the construction of the overall experimental device, the influence of the internal structure of the transformer on the propagation and attenuation of the discharge signal is often ignored. The model is quite different from the actual transformer, and the spatial propagation law of the multi-parameter signal cannot be obtained. Second, the arrangement position of the sensor is single, and the monitoring position does not match the actual input and output line position of the transformer, so the timing characteristics of the discharge signal cannot be obtained.
[0004] Therefore, there is an urgent need for a simulation device and method for the spatiotemporal distribution characteristics of multi-parameter signals of internal discharge defects in large transformers, so as to obtain the spatiotemporal distribution characteristics of multi-parameter signals of internal discharge defects in large transformers, which provides a reliable basis for the active protection identification of discharge defects in large transformers. Summary of the invention
[0005] The purpose of the present invention is to provide a device for simulating the time-space distribution characteristics of multi-parameter signals of internal discharge defects of large transformers, which is characterized by comprising: a large transformer equivalent experimental device and a transformer multi-channel inlet / outlet line equivalent position monitoring device;
[0006] The large transformer equivalent experimental device includes: a 120kV booster, a 10kΩ protection resistor, a capacitor voltage divider, an epoxy barrel, an inter-turn discharge model, a screen, and a 20-equal-division capacitor voltage divider; the transformer multi-channel inlet / outlet line equivalent position monitoring device includes: a first high-frequency current sensor, a second high-frequency current sensor, and a third high-frequency current sensor; the inter-turn discharge model is connected in series with the 20-equal-division capacitor voltage divider to form a discharge defect model.
[0007] A first distance d1 is formed between the inner wall of the epoxy barrel and the screen; a second distance d2 is formed between the screen and the discharge defect model; the first distance d1 and the second distance d2 are restored in a 1:1 relationship according to the distance relationship between the high-voltage winding, the screen, and the box wall inside the 500kV large transformer oil tank.
[0008] The epoxy barrel is a cylindrical oil-filled epoxy barrel, the size of which is 1:1 restored to the size of a 500kV large transformer oil tank, and the epoxy barrel is filled with transformer oil.
[0009] The inter-turn discharge model is a pig-tail discharge model, which is connected in series with a 20-equal-division capacitance divider to restore the ground capacitance and mutual capacitance parameters of the high, medium and low voltage windings inside a 500kV large transformer.
[0010] The first high-frequency current sensor is arranged at the high-voltage lead of the discharge defect model, which is equivalent to the transformer bushing inlet position; the second high-frequency current sensor is arranged at the grounding outlet of the discharge defect model, which is equivalent to the transformer core grounding position; the third high-frequency current sensor is arranged at the oil-filled cavity grounding wire of the epoxy barrel, which is equivalent to the transformer casing grounding position.
[0011] The transformer multi-channel inlet / outlet line equivalent position monitoring device also includes: a UHF sensor and an ultrasonic sensor, and the UHF sensor and the ultrasonic sensor are arranged on one side of the enclosure close to the outer wall of the epoxy barrel.
[0012] The transformer multi-channel input / output line equivalent position monitoring device also includes an oscilloscope, and the first high-frequency current sensor, the second high-frequency current sensor, the third high-frequency current sensor, the ultra-high frequency sensor and the ultrasonic sensor are connected to the oscilloscope. The oscilloscope is connected to the PC through the oscilloscope supporting software to achieve simultaneous monitoring of different positions of five signals.
[0013] The object of the present invention is to provide an equivalent method of a simulation device for the temporal and spatial distribution characteristics of multi-parameter signals of internal discharge defects of large transformers, characterized in that it comprises the following steps:
[0014] The partial discharge test was carried out by using the step-by-step voltage-boosting method. The voltage-boosting interval was 3 minutes and the voltage-boosting amplitude was 1 kV. The signal amplitude changes of the first high-frequency current sensor, the second high-frequency current sensor, the third high-frequency current sensor, the ultra-high-frequency sensor and the ultrasonic sensor were recorded.
[0015] The beneficial effects of the present invention are:
[0016] The present invention discloses a device and method for simulating the spatiotemporal distribution characteristics of a multi-parameter signal of an internal discharge defect of a large transformer. Based on the large transformer equivalent experimental device and the transformer multi-channel inlet / outlet line equivalent position monitoring device, multi-parameter sensors are arranged at the inlet / outlet lines at different positions of the transformer in a test loop to achieve simultaneous monitoring of different positions, analyze the obtained signals, and obtain the spatiotemporal distribution law of the multi-parameter signal of the internal discharge defect of the large transformer.
[0017] By designing and developing the large transformer equivalent experimental device, the actual internal environment of the large transformer can be better simulated in terms of actual size, internal structure, and spatial environment, thereby solving the problem in the prior art that the influence of the actual internal structure of the transformer on the propagation and attenuation of the discharge signal is ignored in the construction of the overall experimental device, the model is quite different from the actual transformer, and the spatial propagation law of the multi-parameter signal cannot be obtained;
[0018] By designing and developing a transformer multi-channel input / output line equivalent position monitoring device, a transformer multi-channel output line equivalent method is proposed. The constructed test circuit restores the input / output lines at different positions of the actual transformer, and realizes simultaneous monitoring of different positions through multi-parameter sensors. Through the effective cooperation of various sensors, the temporal and spatial distribution characteristics of multi-parameter signals during internal discharge are obtained, and the internal characteristic information of the transformer is effectively identified to ensure the accuracy and reliability of active protection warning. The problem of the single spatial arrangement of multi-parameter sensors in the prior art, the mismatch between the monitoring position and the actual input and output line position of the transformer, the inability to obtain the timing characteristics of the discharge signal, and the inability to accurately obtain the propagation law of the multi-parameter signal is solved. The technical problem of inaccurate temporal and spatial distribution law of multi-parameter signals of internal discharge defects of existing large transformers is solved, and a reliable basis is provided for active protection warning of large transformers, thereby laying a foundation for large-scale engineering applications of multi-parameter joint monitoring. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a structural schematic diagram of a device for simulating the spatiotemporal distribution characteristics of multi-parameter signals of internal discharge defects of a large transformer according to the present invention;
[0020] Figure 2 It is a structural schematic diagram of a transformer multi-channel inlet / outlet line equivalent position monitoring device according to an embodiment of the present invention;
[0021] Figure 3A comparison diagram of the amplitude changes of various sensors in an embodiment of the present invention;
[0022] Among them: 1-1: 120kV booster, 1-2: 10kΩ protection resistor, 1-3: capacitor voltage divider, 1-4: epoxy barrel, 1-5: inter-turn discharge model, 1-6: screen, 1-7: 20 equally divided capacitor voltage divider, 2-1: first high-frequency current sensor, 2-2: second high-frequency current sensor, 2-3: third high-frequency current sensor, 2-4: UHF sensor, 2-5: ultrasonic sensor. DETAILED DESCRIPTION
[0023] The present invention provides a device and method for simulating the spatiotemporal distribution characteristics of multi-parameter signals of internal discharge defects of a large transformer. The present invention is further described in detail below in conjunction with the accompanying drawings.
[0024] like Figure 1 The embodiment of the present invention shown discloses a device for simulating the spatiotemporal distribution characteristics of multi-parameter signals of internal discharge defects of a large transformer, comprising:
[0025] A large transformer equivalent experimental device and a transformer multi-way inlet / outlet equivalent position monitoring device; the large transformer equivalent experimental device comprises: a 120kV booster 1-1, a 10kΩ protection resistor 1-2, a capacitor voltage divider 1-3, an epoxy barrel 1-4, an inter-turn discharge model 1-5, a screen 1-6, and a 20-equally divided capacitor voltage divider 1-7; the transformer multi-way inlet / outlet equivalent position monitoring device comprises: a first high-frequency current sensor 2-1, a second high-frequency current sensor 2-2, and a third high-frequency current sensor 2-3; the inter-turn discharge model 1-5 and the 20-equally divided capacitor voltage divider 1-7 are connected in series to form a discharge defect model.
[0026] In this embodiment, the simulation device for the spatiotemporal distribution characteristics of the multi-parameter signal of the internal discharge defect of a large transformer is more in line with the actual situation of the large transformer in terms of actual size, internal structure, and spatial position, and specifically includes:
[0027] 1. The sizes of the epoxy barrels 1-4 are designed and developed according to the equivalent principle of 500kV large transformers;
[0028] 2. Considering the ground capacitance and mutual capacitance of the high, medium and low voltage windings inside the large transformer, connect 20 equally divided capacitive voltage dividers 1-7 in series to the inter-turn discharge model 1-5;
[0029] 3. Arrange the enclosure 1-6 and the overall discharge model according to the spatial position equivalence principle of the internal structure of the large transformer, so that the distance between the epoxy barrel 1-4 and the enclosure 1-6, and between the enclosure 1-6 and the overall discharge model is more realistic.
[0030] The specific features in this embodiment are as follows:
[0031] The epoxy barrel 1-4 is a cylindrical oil-filled epoxy barrel, the size of the epoxy barrel 1-4 is 1:1 restored to the size of a 500kV large transformer oil tank, and the epoxy barrel 1-4 is filled with transformer oil.
[0032] The inter-turn discharge model 1-5 is a pig-tail discharge model, which is connected in series with a 20-equal-division capacitor voltage divider 1-7 to restore the ground capacitance and mutual capacitance parameters of the high, medium and low voltage windings inside a 500kV large transformer.
[0033] like Figure 2 As shown, a first distance d1 is formed between the inner wall of the epoxy barrel 1-4 and the screen 1-6; a second distance d2 is formed between the screen 1-6 and the discharge defect model; the first distance d1 and the second distance d2 are restored in a 1:1 manner according to the distance relationship between the high-voltage winding, the screen, and the box wall inside the 500kV large transformer oil tank.
[0034] In this embodiment, the inter-turn discharge model 1-5 and the 20-equal-division capacitor voltage divider 1-7 constitute an overall discharge model; the distance between the epoxy barrel 1-4, the screen 1-6 and the overall discharge model is restored in a 1:1 manner according to the distance relationship between the high-voltage winding, the screen and the tank wall inside the 500kV large transformer oil tank.
[0035] The first high-frequency current sensor 2-1 is arranged at the high-voltage lead of the discharge defect model, which is equivalent to the transformer bushing input position; the second high-frequency current sensor 2-2 is arranged at the grounding output of the discharge defect model, which is equivalent to the transformer core grounding position; the third high-frequency current sensor 2-3 is arranged at the oil-filled cavity grounding wire of the epoxy barrel 1-4, which is equivalent to the transformer casing grounding position.
[0036] The transformer multi-channel inlet / outlet line equivalent position monitoring device also includes: a UHF sensor 2-4 and an ultrasonic sensor 2-5, which are arranged on one side of the enclosure 1-6 close to the outer wall of the epoxy barrel 1-4.
[0037] The transformer multi-channel input / output line equivalent position monitoring device also includes an oscilloscope, and the first high-frequency current sensor 2-1, the second high-frequency current sensor 2-2, the third high-frequency current sensor 2-3, the ultra-high frequency sensor 2-4 and the ultrasonic sensor 2-5 are connected to the oscilloscope. The oscilloscope is connected to the PC through the oscilloscope supporting software to achieve simultaneous monitoring of different positions of five signals.
[0038] In this embodiment, if Figure 1As shown, the spatial arrangement of the transformer multi-way inlet / outlet equivalent position monitoring device is as follows: a first high-frequency current sensor 2-1 is arranged at the equivalent transformer bushing inlet position at the high-voltage lead; a second high-frequency current sensor 2-2 is arranged at the equivalent transformer core grounding position at the discharge defect model grounding outlet; and a third high-frequency current sensor 2-3 is arranged at the equivalent transformer casing grounding position at the oil-filled cavity grounding wire.
[0039] In an optional embodiment, a UHF sensor 2-4 and an ultrasonic sensor 2-5 are arranged at the position of the equivalent transformer housing to assist the high-frequency current sensor in determining the discharge state.
[0040] In this embodiment, when implementing equivalent monitoring of multiple output lines, the first high-frequency current sensor 2-1, the second high-frequency current sensor 2-2, the third high-frequency current sensor 2-3, the ultra-high frequency sensor 2-4 and the ultrasonic sensor 2-5 are connected to the same oscilloscope, and connected to the PC through the oscilloscope supporting software to achieve simultaneous monitoring of different positions of the five signals.
[0041] In this embodiment, an equivalent experimental device is used to simulate the actual internal environment of a large transformer, and a transformer multi-way outlet equivalent method is proposed when building a test circuit. The transformer multi-way input / output line equivalent position monitoring device applies the transformer multi-way outlet equivalent method to achieve simultaneous monitoring of different positions through multiple sensors, and obtain the multi-parameter signal spatiotemporal distribution characteristics of the internal discharge defects of the large transformer, providing a reliable basis for the active protection identification of the discharge defects of the large transformer.
[0042] The transformer multi-channel output equivalent method is:
[0043] A first high-frequency current sensor 2-1 is arranged at the position of the equivalent transformer bushing inlet at the high-voltage lead; a second high-frequency current sensor 2-2 is arranged at the equivalent transformer core grounding position at the grounding outlet of the discharge defect model; a third high-frequency current sensor 2-3 is arranged at the equivalent transformer casing grounding position at the oil-filled cavity grounding wire; an ultra-high frequency sensor 2-4 and an ultrasonic sensor 2-5 are arranged at the equivalent transformer casing position; the first high-frequency current sensor 2-1, the second high-frequency current sensor 2-2, the third high-frequency current sensor 2-3, the ultra-high frequency sensor 2-4 and the ultrasonic sensor 2-5 are connected to the same oscilloscope, and connected to the PC through the oscilloscope supporting software to realize simultaneous monitoring of different positions of five signals.
[0044] Another embodiment of the present invention discloses an equivalent method for a simulation device of the spatiotemporal distribution characteristics of multi-parameter signals of internal discharge defects of a large transformer according to the embodiment of the present invention, comprising the following steps: performing a partial discharge test using a step-by-step voltage boosting method, with a voltage boosting interval of 3 minutes and a voltage boosting amplitude of 1 kV, and recording changes in signal amplitudes of the first high-frequency current sensor 2-1, the second high-frequency current sensor 2-2, the third high-frequency current sensor 2-3, the ultra-high-frequency sensor 2-4, and the ultrasonic sensor 2-5.
[0045] In this embodiment, a simulation device for the spatiotemporal distribution characteristics of multi-parameter signals of internal discharge defects of large transformers is used, and a partial discharge test is carried out based on a large transformer equivalent experimental device and a transformer multi-channel input / output line equivalent position monitoring device. Multi-parameter sensors are arranged at the input / output lines at different positions of the transformer in the test loop to achieve simultaneous monitoring of different positions. The spatiotemporal distribution law of multi-parameter signals of internal discharge defects of large transformers can be obtained by analyzing the test data.
[0046] The technical principle of the equivalent method of the simulation device of the time-space distribution characteristics of the multi-parameter signal of the internal discharge defect of the large transformer according to the embodiment of the present invention is: the partial discharge test is carried out by the withstand voltage method or the step-up voltage method, and the time-space characteristics of the multi-sensor signal are measured. In the process of discharge development, the appearance time and amplitude of the characteristic signals of the first high-frequency current sensor 2-1, the second high-frequency current sensor 2-2 and the third high-frequency current sensor 2-3 will show certain rules due to being in different inlet / outlet positions. The order of the signal appearance time can reflect the time series distribution characteristics of the discharge. At the same time, the sensor that first appears the signal is used as the criterion for the discharge generation. The ultra-high frequency sensor 2-4 has a high sensitivity to weak discharge and serves as an auxiliary criterion. The difference in signal amplitude reflects the propagation and attenuation law of the characteristic signal in space. The sensor with the largest amplitude is used as the criterion for the severity of the discharge development. The ultrasonic sensor 2-5 has a significant increase in amplitude in the severe discharge stage and serves as an auxiliary criterion.
[0047] In this embodiment, the specific discharge test process is as follows: a partial discharge test is performed using a step-by-step voltage step-up method, with a voltage step-up interval of 3 minutes and a voltage step-up amplitude of 1 kV. The amplitude changes of each sensor signal are recorded as follows: Figure 3 As shown, the temporal and spatial distribution law of multi-parameter signals is obtained.
[0048] The temporal and spatial distribution law of the multi-parameter signal is as follows: when local discharge occurs, the first high-frequency current sensor 2-1 and the ultra-high frequency sensor 2-4 detect the signal first; after 1 minute of pressure resistance, the second high-frequency current sensor 2-2 and the ultrasonic sensor 2-5 detect the signal, among which the sensitivity of the second high-frequency current sensor 2-2 is twice that of the first high-frequency current sensor 2-1; after 2 minutes of pressure resistance, the third high-frequency current sensor 2-3 detects the discharge signal, and the sensitivity is the same as that of the first high-frequency current sensor 2-1.
[0049] In the discharge development stage, in the withstand voltage stage after each voltage boost, the signal amplitudes of the first high-frequency current sensor 2-1 and the ultra-high frequency sensor 2-4 always increase first; 1 minute later, the amplitudes of the second high-frequency current sensor 2-2 and the ultrasonic sensor 2-5 increase, and the sensitivity of the second high-frequency current sensor 2-2 is twice that of the first high-frequency current sensor 2-1; 2 minutes later, the amplitude of the third high-frequency current sensor 2-3 increases, and its sensitivity is the same as that of the first high-frequency current sensor 2-1.
[0050] After analyzing and studying a large amount of experimental data, the inventors obtained the temporal and spatial distribution law of multi-parameter signals, which is as follows: after a discharge defect occurs inside a large transformer, the high-frequency current characteristic signal is first generated at the bushing inlet position, then propagates to the transformer core grounding outlet position, and finally to the transformer casing grounding outlet position; the signal sensitivity of the bushing inlet position and the transformer casing grounding outlet position are consistent, and the sensitivity of the transformer core grounding outlet position is twice that of the former two.
[0051] Based on the time-space distribution law of the multi-parameter signal, the inventor discloses a simulation device and method for the time-space distribution characteristics of the multi-parameter signal of the internal discharge defect of a large transformer. Different from the prior art in which the high-frequency current sensor is generally set at the position of the third high-frequency current sensor 2-3 in this embodiment, the simulation device for the time-space distribution characteristics of the multi-parameter signal of the internal discharge defect of a large transformer disclosed in the present invention arranges the first high-frequency current sensor 2-1 with a faster response at the high-voltage lead of the discharge defect model, which is equivalent to the transformer bushing inlet position; arranges the second high-frequency current sensor 2-2 with a higher sensitivity at the grounding outlet of the discharge defect model, which is equivalent to the transformer core grounding position; and introduces the ultra-high frequency sensor 2-4 and the ultrasonic sensor 2-5 to assist in judgment, so as to obtain the time sequence characteristics of the discharge signal; the ultra-high frequency sensor 2-4 and the ultrasonic sensor 2-5 are arranged on one side of the enclosure 1-6 close to the outer wall of the epoxy barrel 1-4.
[0052] In summary, the present invention discloses a simulation device and method for the spatiotemporal distribution characteristics of a multi-parameter signal of an internal discharge defect of a large transformer. Based on the spatiotemporal distribution law of the multi-parameter signal, firstly, a large transformer equivalent experimental device is designed and developed. The large transformer equivalent experimental device can better simulate the actual internal environment of the large transformer, and solve the technical problem that the spatial propagation law of the multi-parameter signal of the internal discharge defect of the existing large transformer is unclear; secondly, the present invention discloses a transformer multi-channel input / output line equivalent position monitoring device. Based on the transformer multi-channel input / output line equivalent position monitoring device, a test circuit is constructed to restore the input and output lines at different positions of the actual transformer, and simultaneous monitoring of different positions is achieved through a multi-parameter sensor, which solves the technical problem that the spatiotemporal distribution law of the multi-parameter signal of the internal discharge defect of the existing large transformer is inaccurate, and provides a reliable basis for active protection and early warning of large transformers, thereby establishing a foundation for large-scale engineering applications of multi-parameter joint monitoring.
Claims
1. A device for simulating the temporal and spatial distribution characteristics of multi-parameter signals of internal discharge defects in large transformers, characterized in that: include: Large transformer equivalent experimental device and transformer multi-channel inlet / outlet equivalent position monitoring device; The large transformer equivalent experimental device comprises: a 120 kV booster (1-1), a 10 kΩ protection resistor (1-2), a capacitor voltage divider (1-3), an epoxy barrel (1-4), an inter-turn discharge model (1-5), a screen (1-6), and a 20-equal-division capacitor voltage divider (1-7); the transformer multi-channel inlet / outlet line equivalent position monitoring device comprises: a first high-frequency current sensor (2-1), a second high-frequency current sensor (2-2), and a third high-frequency current sensor (2-3); the inter-turn discharge model (1-5) and the 20-equal-division capacitor voltage divider (1-7) are connected in series to form a discharge defect model.
2. The device for simulating the temporal and spatial distribution characteristics of multi-parameter signals of internal discharge defects of large transformers according to claim 1 is characterized in that: A first distance d1 is formed between the inner wall of the epoxy barrel (1-4) and the enclosure (1-6); a second distance d2 is formed between the enclosure (1-6) and the discharge defect model; the first distance d1 and the second distance d2 are restored in a 1:1 relationship according to the distance relationship between the high-voltage winding, enclosure, and box wall inside the oil tank of a 500 kV large transformer.
3. The device for simulating the temporal and spatial distribution characteristics of multi-parameter signals of internal discharge defects of large transformers according to claim 2 is characterized in that: The epoxy barrel (1-4) is a cylindrical oil-filled epoxy barrel, the size of the epoxy barrel (1-4) is 1:1 reduced to the size of a 500kV large transformer oil tank, and the epoxy barrel (1-4) is filled with transformer oil.
4. The device for simulating the temporal and spatial distribution characteristics of multi-parameter signals of internal discharge defects of large transformers according to claim 3 is characterized in that: The inter-turn discharge model (1-5) is a pig-tail discharge model, and the inter-turn discharge model (1-5) is connected in series with a 20-equal-division capacitance divider (1-7) to restore the ground capacitance and mutual capacitance parameters of the high, medium and low voltage windings inside a 500kV large transformer.
5. The device for simulating the temporal and spatial distribution characteristics of multi-parameter signals of internal discharge defects of large transformers according to claim 1 is characterized in that: The first high-frequency current sensor (2-1) is arranged at the high-voltage lead of the discharge defect model, which is equivalent to the transformer bushing inlet position; the second high-frequency current sensor (2-2) is arranged at the grounding outlet of the discharge defect model, which is equivalent to the transformer core grounding position; and the third high-frequency current sensor (2-3) is arranged at the oil-filled cavity grounding wire of the epoxy barrel (1-4), which is equivalent to the transformer shell grounding position.
6. The device for simulating the temporal and spatial distribution characteristics of multi-parameter signals of internal discharge defects of large transformers according to claim 5, characterized in that: The transformer multi-channel inlet / outlet line equivalent position monitoring device further comprises: a UHF sensor (2-4) and an ultrasonic sensor (2-5), wherein the UHF sensor (2-4) and the ultrasonic sensor (2-5) are arranged on one side of the enclosure (1-6) close to the outer wall of the epoxy barrel (1-4).
7. The device for simulating the temporal and spatial distribution characteristics of multi-parameter signals of internal discharge defects of large transformers according to claim 6, characterized in that: The transformer multi-channel inlet / outlet equivalent position monitoring device also includes an oscilloscope, the first high-frequency current sensor (2-1), the second high-frequency current sensor (2-2), the third high-frequency current sensor (2-3), the ultra-high frequency sensor (2-4) and the ultrasonic sensor (2-5) are connected to the oscilloscope, and the oscilloscope is connected to the PC via the oscilloscope supporting software to achieve simultaneous monitoring of different positions of five channels of signals.
8. An equivalent method of the device for simulating the spatiotemporal distribution characteristics of multi-parameter signals of internal discharge defects of large transformers according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: carrying out a partial discharge test by adopting a step-by-step voltage-boosting method, with a voltage-boosting interval of 3 minutes and a voltage-boosting amplitude of 1 kV, and recording changes in signal amplitudes of a first high-frequency current sensor (2-1), a second high-frequency current sensor (2-2), a third high-frequency current sensor (2-3), an ultra-high-frequency sensor (2-4), and an ultrasonic sensor (2-5).