GIS ultrahigh frequency partial discharge test device and acquisition unit

Abstract

The utility model discloses a GIS ultrahigh frequency partial discharge testing device and an acquisition unit, and belongs to the field of high voltage switch equipment, the acquisition unit uses at least two operational amplifiers to form a multistage operational amplifier structure, so that small amplitude signals are amplified, large amplitude signals are pulled down to an effective range to realize acquisition, the range of signal acquisition is effectively expanded, and the acquisition efficiency is improved. The antenna performance difference is leveled to a certain extent, the universality of the GIS ultrahigh frequency partial discharge test acquisition unit is improved, and the problem of poor equipment universality caused by narrow signal acquisition range of a partial discharge test device is solved; meanwhile, each operational amplifier is provided with an AD acquisition channel, data of all the acquisition channels do not interfere with one another, the accuracy of output signals is improved, and the accuracy of data acquisition of the test acquisition unit is further improved.

Description

Technical Field

[0001] The utility model belongs to the field of high-voltage switch equipment, in particular to a GIS ultra-high frequency partial discharge test device and a collection unit. Background Art

[0002] Gas insulated switchgear (GIS) organically combines substation circuit breakers, disconnectors, grounding switches, voltage transformers, lightning arresters, and inlet and outlet bushings into a whole to achieve equipment miniaturization, making equipment installation and maintenance more convenient. However, multiple electrical components are integrated in the narrow space of GIS, and the working field strength is very high. The insulation margin between electrical components is relatively small. Once insulation defects occur inside GIS, partial discharge is easily caused, causing equipment failure.

[0003] Partial discharge refers to the electrical discharge phenomenon in which only part of the insulation between conductors is broken down under the action of an electric field. Partial discharge is a pulse discharge that will produce a series of physical phenomena and chemical changes such as light, sound, electrical and mechanical vibrations inside and around the power equipment. Partial discharge will also generate pulse currents, which will excite high-frequency electromagnetic waves. The severity of the current partial discharge can be determined by detecting high-frequency electromagnetic waves.

[0004] However, during the GIS UHF partial discharge detection process, due to the inconsistent performance of various UHF antennas and the narrow acquisition frequency band of the signal acquisition module of the detection device, different antennas need to be configured with corresponding partial discharge test devices with different detection ranges, resulting in high detection costs.

[0005] In summary, the existing partial discharge test device has a narrow signal acquisition range, resulting in poor versatility of the device. Utility Model Content

[0006] The utility model aims to provide a GIS ultra-high frequency partial discharge test device and a collection unit to solve the technical problem that the partial discharge test device in the prior art has a narrow signal collection range and causes poor versatility of the equipment.

[0007] In order to achieve the above-mentioned purpose, the technical solution of the GIS UHF partial discharge test device and acquisition unit provided by the utility model is:

[0008] A GIS ultra-high frequency partial discharge test acquisition unit comprises an ADC chip and at least two cascaded operational amplifiers. The output signal end of each operational amplifier is connected to the ADC chip through different AD acquisition channels. The ADC chip is used to convert the output signals of each operational amplifier acquired by the AD acquisition channel into digital signals.

[0009] As a further improvement, an envelope detection unit is further provided between the output signal terminal of each operational amplifier and the AD acquisition channel, and the envelope detection unit is used to extract the peak value of the output signal of the corresponding operational amplifier.

[0010] As a further improvement, the operational amplifier adopts a current feedback operational amplifier.

[0011] As a further improvement, the power supply module used in the acquisition unit includes a power supply and a first voltage conversion module and a second voltage conversion module for converting the power supply into a first power supply and a second power supply respectively. The first power supply is used to power each operational amplifier, and the second power supply is used to power the ADC chip.

[0012] As a further improvement, the first voltage conversion module includes a first switching power supply and a first linear regulator, the input end of the first switching power supply is connected to the power supply, the output end of the first switching power supply is connected to the input end of the first linear regulator, and the output end of the first linear regulator outputs the first power supply; the second voltage conversion module includes a second switching power supply and a second linear regulator, the input end of the second switching power supply is connected to the power supply, the output end of the second switching power supply is connected to the input end of the second linear regulator, and the output end of the second linear regulator outputs the second power supply.

[0013] The utility model also discloses a GIS ultra-high frequency partial discharge test device, including a collection unit and a data processing unit for collecting ultra-high frequency signals. The collection unit includes an ADC chip and at least two cascaded operational amplifiers. The output signal end of each operational amplifier is connected to the ADC chip through a different AD collection channel. The ADC chip is used to convert the output signals of each operational amplifier collected by the AD collection channel into digital signals and upload them to the data processing unit. The data processing unit is used to determine whether partial discharge occurs according to the received digital signals.

[0014] As a further improvement, an envelope detection unit is further provided between the output signal terminal of each operational amplifier and the AD acquisition channel, and the envelope detection unit is used to extract the peak value of the output signal of the corresponding operational amplifier.

[0015] As a further improvement, the operational amplifier adopts a current feedback operational amplifier.

[0016] As a further improvement, the power supply module used in the testing device includes a power supply and a first voltage conversion module and a second voltage conversion module for converting the power supply into a first power supply and a second power supply respectively. The first power supply is used to power each operational amplifier, and the second power supply is used to power an ADC chip and a data processing unit.

[0017] As a further improvement, the first voltage conversion module includes a first switching power supply and a first linear regulator, the input end of the first switching power supply is connected to the power supply, the output end of the first switching power supply is connected to the input end of the first linear regulator, and the output end of the first linear regulator outputs the first power supply; the second voltage conversion module includes a second switching power supply and a second linear regulator, the input end of the second switching power supply is connected to the power supply, the output end of the second switching power supply is connected to the input end of the second linear regulator, and the output end of the second linear regulator outputs the second power supply.

[0018] The beneficial effects of the GIS ultra-high frequency partial discharge test acquisition unit of the utility model are as follows: in the utility model, at least two operational amplifiers are used to form a multi-stage operational amplifier structure so that small-amplitude signals can be amplified, and large-amplitude signals can be pulled down to an effective range for acquisition, thereby effectively expanding the range of acquired signals, leveling the differences in antenna performance to a certain extent, improving the versatility of the GIS ultra-high frequency partial discharge test acquisition unit, and solving the problem that the partial discharge test device has a narrow signal acquisition range, resulting in poor equipment versatility; at the same time, each operational amplifier is provided with an AD acquisition channel, and the data of each acquisition channel do not interfere with each other, thereby improving the accuracy of the output signal, and further improving the accuracy of the data collected by the test acquisition unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of a GIS ultra-high frequency partial discharge test acquisition unit in the utility model. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model, that is, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] GIS UHF partial discharge test device embodiment:

[0022] The GIS ultra-high frequency partial discharge test device comprises a collection unit for collecting ultra-high frequency signals, a data processing unit and a power supply module.

[0023] like Figure 1As shown, the acquisition unit includes an ADC chip and at least two cascaded operational amplifiers, each operational amplifier output signal end is connected to the ADC chip through a different AD acquisition channel, and the ADC chip converts the output signal of each operational amplifier acquired by the AD acquisition channel into a digital signal and uploads it to the data processing unit. Preferably, the at least two cascaded operational amplifiers can be at least four cascaded operational amplifiers. In this embodiment, ten cascaded operational amplifiers are used, and ten AD acquisition channels are used to acquire the output signals of each operational amplifier.

[0024] The data processing unit is used to determine whether partial discharge occurs according to the received digital signal. The data processing unit is also used to determine whether partial discharge occurs when the collected data of any AD channel is within a set threshold range.

[0025] In order to improve the efficiency of partial discharge testing, an envelope detection unit is also set between the output signal end of each operational amplifier and the AD acquisition channel. The envelope detection unit is used to extract the peak value of the output signal of the corresponding operational amplifier. The peak points are connected to form a low-frequency envelope curve, which can be regarded as the amplitude information of the signal for reference by the data processing unit.

[0026] In order to improve the accuracy of partial discharge testing when collecting high frequencies, the operational amplifier uses a current feedback operational amplifier.

[0027] The power supply module used in the test device includes a power supply and a first voltage conversion module and a second voltage conversion module for converting the power supply into a first power supply and a second power supply respectively. The first power supply is used to power each operational amplifier, and the second power supply is used to power an ADC chip and a data processing unit.

[0028] Specifically, the first voltage conversion module includes a first switching power supply and a first linear regulator, the input end of the first switching power supply is connected to the power supply, the output end of the first switching power supply is connected to the input end of the first linear regulator, and the output end of the first linear regulator outputs the first power supply. The second voltage conversion module includes a second switching power supply and a second linear regulator, the input end of the second switching power supply is connected to the power supply, the output end of the second switching power supply is connected to the input end of the second linear regulator, and the output end of the second linear regulator outputs the second power supply.

[0029] The power supply is a 24V power supply. The first switching power supply converts the 24V main power supply into +9V and -9V, and then uses the first LDO to convert +9V and -9V into +5V and -5V first power supplies, which are used to power the operational amplifier. The second switching power supply converts the 24V main power supply into +5V, and then uses the second LDO to convert +5V into +3.3V second power supply, which is used to power various chips.

[0030] For the same partial discharge signal, when the amplitude of the signal received by the device is low, it can reach the threshold range after multiple stages of amplification, thereby making a correct judgment; conversely, when the amplitude of the signal received by the device is high, it can reach the threshold range after a small amount of amplification, so it will not be filtered out as interference, thereby improving the accuracy of partial discharge testing.

[0031] This embodiment solves the problem of inaccurate partial discharge detection caused by differences in UHF antenna performance. Specifically, for the same partial discharge signal, the difference in antennas will result in different signal amplitudes transmitted to the detection device. If the amplitude is too small or too large, it will exceed the detection range of the rear-end partial discharge detection device, resulting in missed detection. This embodiment can amplify signals that are too small and pull down signals that are too large to within the effective range, thereby leveling the differences in antenna performance to a certain extent and improving the accuracy of partial discharge detection.

[0032] GIS UHF partial discharge test acquisition unit implementation example:

[0033] like Figure 1 As shown, the GIS ultra-high frequency partial discharge test acquisition unit includes an ADC chip and at least two cascaded operational amplifiers, each operational amplifier output signal end is connected to the ADC chip through a different AD acquisition channel, and the ADC chip converts the output signal of each operational amplifier acquired by the AD acquisition channel into a digital signal. This embodiment is implemented with reference to the above-mentioned embodiment of the GIS ultra-high frequency partial discharge test device, and will not be repeated here.

[0034] Finally, it should be noted that the above is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments without creative work, or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A GIS ultra-high frequency partial discharge test acquisition unit, characterized in that: It includes an ADC chip and at least two cascaded operational amplifiers. The output signal end of each operational amplifier is connected to the ADC chip through different AD acquisition channels. The ADC chip is used to convert the output signals of each operational amplifier collected by the AD acquisition channel into digital signals.

2. The GIS ultra-high frequency partial discharge test acquisition unit according to claim 1, characterized in that: An envelope detection unit is also provided between the output signal terminal of each operational amplifier and the AD acquisition channel, and the envelope detection unit is used to extract the peak value of the output signal of the corresponding operational amplifier.

3. The GIS UHF partial discharge test acquisition unit according to claim 1, characterized in that: The operational amplifier is a current feedback operational amplifier.

4. The GIS UHF partial discharge test acquisition unit according to claim 1, characterized in that: The power supply module used in the acquisition unit includes a power supply and a first voltage conversion module and a second voltage conversion module for converting the power supply into a first power supply and a second power supply respectively. The first power supply is used to power each operational amplifier, and the second power supply is used to power an ADC chip.

5. The GIS UHF partial discharge test acquisition unit according to claim 4, characterized in that: The first voltage conversion module includes a first switching power supply and a first linear regulator, the input end of the first switching power supply is connected to the power supply, the output end of the first switching power supply is connected to the input end of the first linear regulator, and the output end of the first linear regulator outputs the first power supply; the second voltage conversion module includes a second switching power supply and a second linear regulator, the input end of the second switching power supply is connected to the power supply, the output end of the second switching power supply is connected to the input end of the second linear regulator, and the output end of the second linear regulator outputs the second power supply.

6. A GIS ultra-high frequency partial discharge test device, characterized in that: The invention comprises an acquisition unit and a data processing unit for acquiring ultra-high frequency signals. The acquisition unit comprises an ADC chip and at least two cascaded operational amplifiers. The output signal end of each operational amplifier is connected to the ADC chip through different AD acquisition channels. The ADC chip is used to convert the output signals of each operational amplifier acquired by the AD acquisition channel into digital signals and upload them to the data processing unit. The data processing unit is used to determine whether partial discharge occurs according to the received digital signals.

7. The GIS ultra-high frequency partial discharge test device according to claim 6, characterized in that: An envelope detection unit is also provided between the output signal terminal of each operational amplifier and the AD acquisition channel, and the envelope detection unit is used to extract the peak value of the output signal of the corresponding operational amplifier.

8. The GIS ultra-high frequency partial discharge test device according to claim 6, characterized in that: The operational amplifier is a current feedback operational amplifier.

9. The GIS ultra-high frequency partial discharge test device according to claim 6, characterized in that: The power supply module used in the test device includes a power supply and a first voltage conversion module and a second voltage conversion module for converting the power supply into a first power supply and a second power supply respectively. The first power supply is used to power each operational amplifier, and the second power supply is used to power an ADC chip and a data processing unit.

10. The GIS ultra-high frequency partial discharge test device according to claim 9, characterized in that: The first voltage conversion module includes a first switching power supply and a first linear regulator, the input end of the first switching power supply is connected to the power supply, the output end of the first switching power supply is connected to the input end of the first linear regulator, and the output end of the first linear regulator outputs the first power supply; the second voltage conversion module includes a second switching power supply and a second linear regulator, the input end of the second switching power supply is connected to the power supply, the output end of the second switching power supply is connected to the input end of the second linear regulator, and the output end of the second linear regulator outputs the second power supply.

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