Flexible deployment type global full-duration partial discharge detection system and method

Abstract

The invention relates to a flexible deployment type global full-duration partial discharge detection system and method, the system comprises a signal acquisition module, a power frequency synchronization module, a power supply communication module and an analysis and diagnosis module, the power frequency synchronization module obtains the real-time power frequency of a power grid by using a UDP power frequency synchronization device, and sends the real-time power frequency to a digital sensor; the signal processing module digitizes the ultrahigh frequency signal on site, converts the ultrahigh frequency signal into continuous real-time monitoring data and transmits the continuous real-time monitoring data to the power supply communication module; the power supply communication module is used for providing a stable power supply capable of continuously working for a long time for the digital sensor and transmitting continuous real-time monitoring data to the analysis and diagnosis module; and the analysis and diagnosis module is used for receiving the continuous real-time monitoring data and carrying out partial discharge detection. Compared with the prior art, the method has the advantages that a large amount of on-site deployment working hours are saved, the requirements of rapid deployment, full-station coverage and reliable discovery of accidental intermittent signals can be met, and synchronous long-time continuous monitoring of partial discharge of the GIS equipment in the full station is realized.

Description

Technical Field

[0001] The present invention relates to the field of partial discharge state detection, and in particular to a flexible deployment type full-domain full-time partial discharge detection system and method. Background Art

[0002] As an effective detection method and analysis and diagnosis technology, partial discharge status detection of power equipment can timely and accurately grasp the health status of equipment and ensure the safe, reliable and economical operation of equipment. Among them, ultra-high frequency partial discharge live detection is the best means to detect GIS (gas-insulated metal-enclosed switchgear) insulation defects at an early stage. At present, there are three main types of mainstream ultra-high frequency partial discharge detection technologies:

[0003] Inspection technology based on handheld single-channel detection device can detect and discover suspected partial discharge signals;

[0004] Based on the analysis and positioning technology of portable multi-channel diagnostic devices, the type judgment and positioning of suspected abnormal signals can be realized;

[0005] Based on the long-term monitoring technology of the mobile intensive care unit, the tracking and analysis of the changing trend of the partial discharge signal is realized.

[0006] At present, there are two types of equipment used to detect partial discharge in switch cabinets: handheld partial discharge testers and online partial discharge testers. Handheld partial discharge testers require testers to be dispatched to conduct regular inspections of all electrical equipment to be tested, with a detection cycle of 1-2 times a year. When partial discharge occurs in electrical equipment, the detection frequency needs to be increased according to the severity of the partial discharge phenomenon. However, due to the need for the participation of testers, real-time online continuous monitoring is not possible, and the workload of each test is large. Online partial discharge testers can monitor equipment online continuously in real time, but the number of partial discharge testers required is huge, the total cost is high, and there are also disadvantages such as large size, fixed installation location, inconvenient installation and disassembly, external power supply and supporting communication receiving and processing devices, which make it difficult to promote and use it widely.

[0007] Traditional UHF sensors are analog devices that transmit analog signals through coaxial cables. Due to cable attenuation, the distance between the sensor and the acquisition unit generally cannot exceed 20 meters, making flexible deployment impossible.

[0008] In traditional detection systems, sensors and signal aggregation devices are connected in a star configuration, and each sensor needs to be connected to the signal aggregation device one by one, which consumes a lot of cables. At the same time, due to the complex wiring layout, it is difficult to achieve rapid and convenient deployment between different substations.

[0009] According to statistics, for GIS equipment, in the partial discharge diagnosis link, about 30% of the partial discharge signals caused by insulation defects are intermittent and sporadic signals, which are difficult to detect based on patrol inspection technology. They can only be found through uninterrupted continuous monitoring and accumulated long-term PRPD spectrum. The accumulated PRPD spectrum must have accurate frequency synchronization information. If the frequency cannot be synchronized in real time, the accumulated PRPD spectrum will be seriously distorted, and the partial discharge signal cannot be identified, which will eventually lead to missed detection. Summary of the invention

[0010] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a flexible deployment type full-area and full-time partial discharge detection system and method, so as to realize the synchronous long-term continuous monitoring of partial discharge of the entire station GIS equipment.

[0011] The purpose of the present invention can be achieved by the following technical solutions:

[0012] A flexible deployment type full-area full-time partial discharge detection system, including a signal acquisition module, a power frequency synchronization module, a power supply communication module and an analysis and diagnosis module, wherein:

[0013] The power frequency synchronization module uses the UDP power frequency synchronization device to obtain the real-time power frequency of the power grid from the 220V maintenance power supply or power frequency current transformer and sends it to the digital sensor;

[0014] A signal processing module, which uses the digital sensor to digitize the ultra-high frequency signal in the real-time power frequency on-site, converts it into continuous real-time monitoring data, and transmits it to the power supply communication module via a wired manner;

[0015] A power supply communication module, which provides a stable power supply for the digital sensor to work continuously for a long time, and transmits continuous real-time monitoring data to the analysis and diagnosis module;

[0016] The analysis and diagnosis module receives the continuous real-time monitoring data and performs partial discharge detection through the analysis and diagnosis background.

[0017] Furthermore, the UHF signal is digitized on-site by the digital sensor and converted into continuous real-time monitoring data, thereby realizing long-distance lossless transmission of the continuous real-time monitoring data.

[0018] Furthermore, the digital sensor is composed of a sensor array, which collects ultra-high frequency electromagnetic waves on site and transmits them sequentially to the series power supply communication unit in a wired manner.

[0019] Furthermore, the sensor arrays are connected in series in a daisy chain structure to transmit signals and power.

[0020] Furthermore, the UDP power frequency synchronization device sends the real-time power frequency of the power grid to the digital sensor through network broadcasting based on the power frequency real-time synchronization technology of the network protocol.

[0021] Furthermore, the stable power supply includes multiple types of 220kV AC power supply, lithium battery and CT power supply.

[0022] Furthermore, the power supply communication unit wirelessly transmits the continuous real-time detection data of the digital sensor to the analysis and diagnosis background.

[0023] Furthermore, the wireless mode is a wireless Ethernet WiFi connection.

[0024] Furthermore, the analysis and diagnosis background adopts a movable cabinet with a built-in network switch, an industrial computer and diagnostic analysis software to receive, analyze and diagnose the continuous real-time detection data.

[0025] According to another aspect of the present invention, a flexible deployment type full-area full-duration partial discharge detection method is provided, comprising the following steps:

[0026] The UDP power frequency synchronization device is used to obtain the real-time power frequency of the power grid and send it to the digital sensor through network broadcast;

[0027] The UHF signal collected in the real-time power frequency is digitized locally by the digital sensor, converted into continuous real-time monitoring data, and transmitted to the power supply communication unit by wired means;

[0028] The continuous real-time monitoring data is transmitted to the analysis and diagnosis background through the power supply communication unit for partial discharge detection.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. Each sensor array of the present invention is respectively connected to a power supply communication unit and a UDP power frequency synchronization device, and is powered by a battery or CT to reduce the deployment of on-site power sockets. Then, the power supply communication module is connected to the analysis and diagnosis module via WIFI to transmit partial discharge data and perform statistics on the accumulated PRPD spectrum, thereby achieving reliable detection of intermittent signals and reducing on-site cable deployment. On-site disassembly or deployment can be quickly completed within 8 hours.

[0031] 2. The present invention adopts a combination of wired and wireless methods. Each module can be directly installed or connected on site without the need for civil construction. The UHF sensor relies on a daisy chain structure to form a number of sensor arrays, which is convenient for rapid deployment and meets 7*24 hours of uninterrupted data collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the principle flow chart of the present invention;

[0033] Figure 2 2 is a comparison diagram of the PRPD spectra of unipolar suspended potential discharge with and without real-time grid frequency, where (2a) is the PRPD spectrum with real-time grid frequency, and (2b) is the PRPD spectrum without real-time grid frequency. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0035] Abbreviations involved:

[0036] Gas-insulated metal-enclose switchgear: gas-insulated metal-enclose switchgear, GIS

[0037] Example 1

[0038] This embodiment provides a flexible deployment type full-area full-time partial discharge detection system, including:

[0039] The power frequency synchronization module uses the UDP power frequency synchronization device to obtain the precise frequency of the power grid from the 220V maintenance power supply or the power frequency current transformer. The real-time power frequency synchronization technology based on the network protocol sends the real-time power frequency of the power grid to the digital sensor, ensuring that each sensor obtains the real-time power grid frequency in real time, realizing the correct statistics of the accumulated PRPD spectrum and the reliable detection of partial discharge signals.

[0040] Signal processing module, the digital sensor includes several sensor arrays, each sensor array is serially connected in a daisy chain structure to transmit signals and power, continuously collects ultra-high frequency electromagnetic waves on site, digitizes the ultra-high frequency signals on site, and transmits them in real time to the series power supply communication unit in sequence through wired means; the daisy chain series connection technology enables the sensors in each interval to be powered and communicated in a cascade manner, greatly reducing the use of cables, improving the flexibility of on-site installation, and improving deployment efficiency.

[0041] The power supply communication module supports 220kV AC power supply, lithium battery and CT power supply, and is connected to the digital sensor through a network cable to provide a stable power supply for long-term continuous operation of the digital sensor; the power supply communication unit transmits the monitoring data to the analysis and diagnosis background through a wireless Ethernet WiFi connection, and sends the data of the sensor chain to the analysis and diagnosis background in real time. At the same time, the power supply communication unit can obtain power from the nearest maintenance power box and can be powered by a large-capacity lithium battery. Through the solution of local power supply and wired and wireless integration, the deployment of network cables between intervals is eliminated, the deployment efficiency is further improved, and the cost of cable auxiliary materials is reduced.

[0042] The analysis and diagnosis module receives continuous real-time monitoring data and performs partial discharge detection through the analysis and diagnosis background. The analysis and diagnosis background adopts a movable cabinet with a built-in network switch, industrial computer and diagnostic analysis software, which is deployed on site to receive, analyze and diagnose data, and realizes the cloud display of monitoring data and diagnostic results through the built-in 4G communication module.

[0043] like Figure 1 As shown in the figure, each digital sensor daisy chain string is composed of N digital sensors, which obtain stable power supply through the local power supply communication unit and send the detection data to the power supply communication unit in real time. The power supply communication unit draws power from the 220V maintenance power supply on site, or is powered by a large-capacity lithium battery, and sends the data of this string of sensors to the analysis and diagnosis background through the WiFi wireless network. The analysis and diagnosis background is configured with a high-power WiFi hotspot, which can provide a stable WiFi network covering the entire station, receive the detection data of the sensor, and provide the sensor with real-time power grid frequency information. The analysis and diagnosis background is configured with a 4G network terminal, so that the operation and maintenance personnel can remotely access the analysis and diagnosis background in real time to view the detection data and alarm information.

[0044] Real-time synchronization of grid frequency is a necessary function for live partial discharge detection. The signal acquisition unit must be able to obtain the grid frequency in real time to ensure the correct statistical drawing of the partial discharge pulse sequence spectrum (PRPS) and the partial discharge phase spectrum (PRPD). The PRPS and PRPD spectra are the only criteria for determining whether there is a partial discharge signal and the type of partial discharge defect. Figure 2 The 1-minute cumulative PRPD spectrum of a unipolar suspended potential discharge with and without real-time grid frequency is compared. The cumulative PRPD spectrum with real-time grid frequency is as follows: Figure 2 As shown in (2a), the cumulative PRPD spectrum without real-time grid frequency is as follows Figure 2By comparison, it can be seen that when it is necessary to detect intermittent and occasional partial discharge signals by continuously collecting and accumulating PRPD spectra, if the real-time frequency of the power grid cannot be reliably obtained, the accumulated PRPD spectrum cannot reflect the spectrum characteristics of partial discharge, and the existence of partial discharge signals cannot be determined.

[0045] The flexible deployment type full-area full-time partial discharge detection system has reliable detection capabilities for intermittent and sporadic partial discharge phenomena with "small pulses and few pulses" characteristics. Due to the partially active power supply mode of the sensor, the continuous collection of partial discharge ultra-high frequency signals is guaranteed. The convergence of the whole station signal adopts a mixed mode of wired and wireless, with wired communication within the interval and wireless communication between intervals, which saves a lot of man-hours for on-site deployment and realizes full-station detection and rapid deployment.

[0046] Example 2

[0047] This embodiment provides a flexible deployment type full-area full-duration partial discharge detection method, including the following steps:

[0048] The UDP power frequency synchronization device is used to obtain the real-time power frequency of the power grid and send it to the digital sensor through network broadcast;

[0049] The UHF signal collected in the real-time power frequency is digitized on-site by a digital sensor, converted into continuous real-time monitoring data, and transmitted to the power supply communication unit by wire;

[0050] The continuous real-time monitoring data is transmitted to the analysis and diagnosis background through the power supply communication unit for partial discharge detection.

[0051] The rest is the same as in Example 1.

[0052] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A flexible deployment type full-area full-time partial discharge detection system, characterized in that: It includes signal acquisition module, power frequency synchronization module, power supply communication module and analysis and diagnosis module, among which: The power frequency synchronization module uses the UDP power frequency synchronization device to obtain the real-time power frequency of the power grid from the 220V maintenance power supply or power frequency current transformer and sends it to the digital sensor; A signal processing module, which uses the digital sensor to digitize the ultra-high frequency signal in the real-time power frequency on-site, converts it into continuous real-time monitoring data, and transmits it to the power supply communication module via a wired manner; A power supply communication module, which provides a stable power supply for the digital sensor to work continuously for a long time, and transmits continuous real-time monitoring data to the analysis and diagnosis module; The analysis and diagnosis module receives the continuous real-time monitoring data and performs partial discharge detection through the analysis and diagnosis background.

2. The flexible deployment type full-area full-time partial discharge detection system according to claim 1 is characterized in that: The ultra-high frequency signal is digitized on-site through the digital sensor and converted into continuous real-time monitoring data, thereby realizing long-distance lossless transmission of the continuous real-time monitoring data.

3. The flexible deployment type full-area full-time partial discharge detection system according to claim 1 is characterized in that: The digital sensor is composed of a sensor array, which collects ultra-high frequency electromagnetic waves on site and transmits them to the series power supply communication unit in sequence through a wired manner.

4. The flexible deployment type full-area full-time partial discharge detection system according to claim 3 is characterized in that: The sensor arrays are connected in series in a daisy chain configuration and transmit signals and power.

5. The flexible deployment type full-area full-time partial discharge detection system according to claim 1 is characterized in that: The UDP power frequency synchronization device is based on the power frequency real-time synchronization technology of the network protocol, and sends the real-time power frequency of the power grid to the digital sensor through network broadcasting.

6. The flexible deployment type full-area full-time partial discharge detection system according to claim 1 is characterized in that: The stable power supply includes multiple types of 220kV AC power supply, lithium battery and CT power supply.

7. The flexible deployment type full-area full-time partial discharge detection system according to claim 1 is characterized in that: The power supply communication unit wirelessly transmits the continuous real-time detection data of the digital sensor to the analysis and diagnosis background.

8. The flexible deployment type full-area full-time partial discharge detection system according to claim 7 is characterized in that: The wireless mode is a wireless Ethernet WiFi connection.

9. The flexible deployment type full-area full-time partial discharge detection system according to claim 1 is characterized in that: The analysis and diagnosis background adopts a movable cabinet, with a built-in network switch, an industrial computer and diagnosis and analysis software, to receive, analyze and diagnose the continuous real-time detection data.

10. A flexible deployment type full-area full-time partial discharge detection method, characterized in that: The following steps are involved: Use the UDP power frequency synchronization device to obtain the real-time power frequency of the power grid and send it to the digital sensor through network broadcast; The UHF signal collected in the real-time power frequency is digitized locally by the digital sensor, converted into continuous real-time monitoring data, and transmitted to the power supply communication unit by wired means; The continuous real-time monitoring data is transmitted to the analysis and diagnosis background through the power supply communication unit for partial discharge detection.

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