Flexibly deployable full-coverage full-time partial discharge detection system and method

Abstract

A flexibly deployable full-coverage full-time partial discharge detection system and method. The system comprises a signal collection module, a power frequency synchronization module, a power supply and communication unit and an analysis and diagnosis module, wherein the power frequency synchronization module obtains a real-time power frequency of a grid by using a UDP power-frequency synchronization apparatus, and sends the real-time power frequency to a digital sensor; a signal processing module digitizes an ultra-high frequency signal in situ to convert same into real-time continuous monitoring data, and transmits the real-time continuous monitoring data to the power supply and communication unit; the power supply and communication unit provides a continuously operating long-term stable power source for the digital sensor, and transmits the real-time continuous monitoring data to the analysis and diagnosis module; and the analysis and diagnosis module receives the real-time continuous monitoring data and performs partial discharge detection. Compared with the prior art, by means of the present invention, on-site deployment labor is significantly saved on, the requirements for rapid deployment, full-station coverage and reliable detection of sporadic intermittent signals can be met, and continuous long-term monitoring with respect to partial discharge is synchronously implemented for all GIS devices across a station.

Description

Flexible deployment type global full-time local discharge detection system and method TECHNICAL FIELD

[0001] The present application relates to the field of local discharge state detection, in particular to a flexible deployment type global full-time local discharge detection system and method. BACKGROUND

[0002] The local discharge state detection of power equipment is an effective detection means and analysis and diagnosis technology, which can timely and accurately master the health state of the equipment and ensure the safe, reliable and economic operation of the equipment. Among them, the UHF local discharge on-line detection is the best means for early detection of GIS (gas-insulated metal-enclose switchgear) insulation defects. At present, the mainstream UHF partial discharge detection technology mainly has three categories:

[0003] The patrol technology based on a handheld single-channel detection device realizes the detection and discovery of suspected partial discharge signals;

[0004] The analysis and positioning technology based on a portable multi-channel diagnosis device realizes the type judgment and positioning of suspected abnormal signals;

[0005] The long-time monitoring technology based on a mobile intensive care device realizes the tracking analysis of the change trend of the partial discharge signals.

[0006] At present, the devices used to detect the local discharge phenomenon of switch cabinets include handheld partial discharge testers and on-line partial discharge testers. The handheld partial discharge tester requires to dispatch testers to detect all electrical equipment to be tested regularly, and the detection cycle is 1-2 times per year. When the electrical equipment has local discharge, the detection frequency needs to be increased according to the severity of the local discharge phenomenon. However, due to the need of testers, it is impossible to realize real-time online continuous monitoring, and the workload of each test is large. The on-line partial discharge tester can realize online continuous real-time monitoring of the equipment, but the number of required partial discharge testers is huge, the total cost is high, and in addition, there are the following shortcomings: large size, fixed installation position, inconvenient installation and removal, external power supply and supporting communication receiving and processing devices, etc., which makes it difficult to be widely used.

[0007] The traditional UHF sensor is an analog device, which transmits analog signals through a coaxial cable. The distance between the sensor and the collection unit generally cannot exceed 20 meters due to the influence of cable attenuation, and flexible deployment cannot be realized.

[0008] The traditional detection system adopts star connection between sensors and signal converging devices, each sensor and signal converging device needs to be connected one by one, and the cable consumption is huge. Meanwhile, due to the complex wiring layout, it is difficult to realize rapid deployment and convenient deployment between different substations.

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

[0010] The purpose of the present application is to overcome the defects of the prior art and provide a flexible deployment type global full-time partial discharge detection system and method, which realizes long-time continuous monitoring of GIS equipment partial discharge in the whole station.

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

[0012] A flexible deployment type global full-time partial discharge detection system, comprising 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 obtains the real-time power frequency of the power grid from the 220V maintenance power supply or the power frequency current transformer by using the UDP power frequency synchronization device, and sends it to the digital sensor;

[0014] The signal processing module digitizes the ultra-high frequency signal in the real-time power frequency on site by using the digital sensor, converts it into continuous real-time monitoring data, and transmits it to the power supply communication module through a wired mode;

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

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

[0017] Further, the ultra-high frequency signal is digitized on site by the digital sensor, converted into continuous real-time monitoring data, and the continuous real-time monitoring data is transmitted remotely without damage.

[0018] Further, the digital sensor is composed of a sensor array, which collects the ultra-high frequency electromagnetic wave and transmits the signal to the serial power supply communication unit through a wired mode.

[0019] Further, the sensor array is connected in series in a daisy chain mode and transmits the signal and power supply.

[0020] Further, the UDP power frequency synchronization device synchronizes the real-time power frequency of the power grid based on the network protocol, and broadcasts the real-time power frequency of the power grid to the digital sensor through the network.

[0021] Further, the stable power supply includes 220kV AC power supply, lithium battery and CT power supply.

[0022] Further, the power supply communication unit transmits the continuous real-time detection data of the digital sensor to the analysis and diagnosis background through a wireless mode.

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

[0024] Further, the analysis and diagnosis background adopts a movable cabinet mode, and is internally provided with a network switch, an industrial computer and diagnosis and analysis software, so as to receive, analyze and diagnose the continuous real-time detection data.

[0025] According to another aspect of the present application, a flexible deployment type global full-time local discharge detection method is provided, which comprises the following steps:

[0026] The UDP power frequency synchronization device is used to obtain the real-time power frequency of the power grid, and the real-time power frequency is broadcasted to the digital sensor through the network.

[0027] The digital sensor is used to digitize the ultra-high frequency signal collected in the real-time power frequency, and convert the signal into continuous real-time monitoring data, which is transmitted to the power supply communication unit through a wired mode.

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

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

[0030] 1. Each sensor array of the present application is connected to the power supply communication unit and the UDP power frequency synchronization device, and is powered by a battery or a CT power supply, so as to reduce the deployment of the power supply socket on site, and then the power supply communication module is connected to the analysis and diagnosis module through WIFI, and the local discharge data is transmitted, the cumulative PRPD graph is counted, the reliable detection of the intermittent signal is realized, the on-site cable deployment is reduced, and the on-site disassembly or deployment can be completed within 8 hours.

[0031] 2. The application adopts a combination of wired and wireless modes, each module can be directly installed or connected on site without civil construction, and the UHF sensor relies on a daisy chain structure to form a number of sensor arrays, facilitating rapid deployment and meeting 7*24-hour uninterrupted data acquisition. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a principle flowchart of the application;

[0033] Figure 2 is a comparison chart of single polarity suspension potential discharge PRPD pattern with and without real-time power grid frequency, wherein (2a) is the PRPD pattern with real-time power grid frequency, and (2b) is the PRPD pattern without real-time power grid frequency. DETAILED DESCRIPTION

[0034] The application will be described in detail below in combination with the drawings and specific embodiments. The embodiments are implemented on the premise of the technical scheme of the application, and detailed implementation modes and specific operation processes are given, but the protection scope of the application is not limited to the following embodiments.

[0035] English abbreviations involved:

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

[0037] Example 1

[0038] The embodiment provides a flexible deployment type global full-time length partial discharge detection system, which comprises:

[0039] The power frequency synchronization module obtains the accurate frequency of the power grid from the 220V maintenance power supply or the power frequency current transformer by using the UDP power frequency synchronization device, and sends the real-time power frequency of the power grid to the digital sensor based on the network protocol real-time synchronization technology of power frequency, so that the real-time power frequency of the power grid is obtained by each sensor, and correct statistics of the cumulative PRPD pattern and reliable detection of the partial discharge signal are realized.

[0040] The signal processing module comprises a number of sensor arrays, each sensor array is connected in series in a daisy chain structure and transmits signals and power supply, and continuously collects the on-site UHF electromagnetic wave, digitizes the UHF signal on site, and transmits the UHF signal to the series power supply communication unit in real time through a wired mode; the daisy chain series connection technology enables the sensors in each interval to be powered and communicated through cascading, greatly reduces the amount of cable used, improves the flexibility of on-site installation, and improves the deployment efficiency.

[0041] The power supply communication module supports 220 kV AC power supply, lithium battery and CT power supply, is connected with the digital sensor through a network cable, and provides a stable power supply for the digital sensor to work continuously for a long time. 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 nearby maintenance power supply box and can supply power through a large-capacity lithium battery. Through the scheme of local power supply, wired and wireless fusion, 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 through the analysis and diagnosis background and performs partial discharge detection. The analysis and diagnosis background adopts a movable cabinet mode, and is internally provided with a network switch, an industrial computer and diagnosis and analysis software, is deployed on site, receives, analyzes and diagnoses data, and realizes cloud display of monitoring data and diagnosis results through a built-in 4G communication module.

[0043] As shown in FIG. 1, each digital sensor daisy chain string is composed of N digital sensors, obtains stable power supply through the local power supply communication unit, and sends the detection data to the power supply communication unit in real time. The power supply communication unit obtains power from the 220V maintenance power supply locally or supplies power through a large-capacity lithium battery, and sends the sensor data of the string to the analysis and diagnosis background through a 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 whole station, receive the detection data of the sensor, and provide real-time power grid frequency information for the sensor. 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 power grid frequency is a necessary function of partial discharge on-line detection. The signal acquisition unit must be able to obtain the power grid frequency in real time to ensure the correct statistical drawing of the partial discharge pulse sequence (PRPS) and the partial discharge phase pattern (PRPD), and the PRPS and PRPD patterns are the only criterion for judging whether there is a partial discharge signal and the type of partial discharge defect. FIG. 2 compares the 1-minute cumulative PRPD pattern of a single polarity suspended potential discharge with and without real-time power grid frequency. The cumulative PRPD pattern with real-time power grid frequency is shown in (2a) of FIG. 2, and the cumulative PRPD pattern without real-time power grid frequency is shown in (2b) of FIG. 2. By comparison, when it is necessary to detect intermittent and occasional partial discharge signals by continuously collecting and accumulating PRPD patterns, if the real-time power grid frequency cannot be reliably obtained, the cumulative PRPD pattern cannot reflect the pattern characteristics of partial discharge, and it is impossible to judge the existence of partial discharge signals.

[0045] The flexible deployment type global full-time partial discharge detection system has reliable detection capability for the intermittent and occasional partial discharge phenomenon with the characteristics of "small pulse, few pulses". Due to the active power supply mode of the sensor part, the continuous collection of the partial discharge ultra-high frequency signal is ensured. The convergence of the signals of the whole station adopts a mixed mode of wired and wireless, uses wired communication within the interval and wireless communication between the intervals, saves a lot of on-site deployment working hours, and realizes the whole station detection and rapid deployment.

[0046] Embodiment 2

[0047] The embodiment provides a flexible deployment type global full-time partial discharge detection method, comprising the following steps:

[0048] The power grid real-time power frequency is obtained by using the UDP power frequency synchronization device, and is sent to the digital sensor through network broadcast;

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

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

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

[0052] The above describes the preferred embodiments of the application in detail. It should be understood that those skilled in the art can make many modifications and changes without creative labor according to the concept of the application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment on the basis of the prior art according to the concept of the application should be within the protection scope determined by the claims.

Claims

1. A flexible deployment type global full-time local partial discharge detection system, characterized in that, It comprises a signal acquisition module, a power frequency synchronization module, a power supply communication module and an analysis and diagnosis module, wherein: The power frequency synchronization module obtains the real-time power frequency of the power grid from the 220V maintenance power supply or the power frequency current transformer using the UDP power frequency synchronization device and sends it to the digital sensor; The signal processing module 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 through a wired mode; The power supply communication module provides stable power supply for the continuous operation of the digital sensor and transmits the continuous real-time monitoring data to the analysis and diagnosis module; The analysis and diagnosis module receives the continuous real-time monitoring data through the analysis and diagnosis background and performs partial discharge detection.

2. The flexible deployment type global full-time length partial discharge detection system according to claim 1, characterized in that, The digital sensor digitizes the ultra-high frequency signal on site, converts it into continuous real-time monitoring data, and realizes the long-distance non-destructive transmission of the continuous real-time monitoring data.

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

4. The flexible deployment type global full-time length partial discharge detection system according to claim 3, characterized in that, The sensor array is connected in series in a daisy chain structure and transmits signals and power supply.

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

6. The flexible deployment type global full-time length partial discharge detection system according to claim 1, wherein, The stable power supply includes multiple types of 220kV AC power supply, lithium battery and CT power supply.

7. The flexible deployment type global full-time length partial discharge detection system according to claim 1, characterized in that, The power supply communication unit transmits the continuous real-time detection data of the digital sensor to the analysis and diagnosis background in a wireless mode.

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

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

10. A flexible deployment type global full-time length partial discharge detection method, characterized in that, It comprises the following steps: The UDP power frequency synchronization device obtains the real-time power frequency of the power grid and broadcasts it to the digital sensor through the network; The digital sensor digitizes the ultra-high frequency signal collected in the real-time power frequency on site, converts it into continuous real-time monitoring data, and transmits it to the power supply communication unit through a wired mode; The power supply communication unit transmits the continuous real-time monitoring data to the analysis and diagnosis background for partial discharge detection.

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