Partial discharge digital monitoring method and system

Abstract

The invention discloses a partial discharge digital monitoring method and system. A digital sensor is used for collecting partial discharge signals, obtaining the real-time frequency of a power grid and converting the real-time frequency into a power frequency phase, partial discharge detection data containing the power frequency phase are sent to a signal collection terminal through a POE network cable, and the voltage frequency is synchronized and digitalized in real time. The wireless acquisition system is wirelessly connected with the analysis and diagnosis background, and the sensors are connected through a series topological structure, so that redundant wiring is reduced, sensor signals are acquired, the frequency of a power grid is synchronized in a UDP broadcast mode, a closed loop of'accurate synchronization-reliable transmission-intelligent operation and maintenance 'is realized, and the reliability of the system is improved. A data basis of millimeter-level space-time precision is provided for state evaluation of the power equipment; the 4G / WIFI unit ensures that partial discharge data is synchronously transmitted to the background, and remote alarm and control are supported.

Description

Technical Field

[0001] This invention relates to the field of online partial discharge monitoring technology, and in particular to a digital monitoring method and system for partial discharge. Background Technology

[0002] Traditional substation GIS / GIL equipment monitoring systems have significant drawbacks: digital sensors lack analog interfaces and cannot directly obtain the real-time frequency of the power grid from the 220V power supply or PT, resulting in the partial discharge signal and the power frequency phase being unable to be accurately synchronized; wired transmission relies on a large number of cables, which makes construction difficult and maintenance costs high in high-voltage environments; and existing systems are unable to support high-speed wireless aggregation and remote diagnosis of multi-sensor data. Summary of the Invention

[0003] The purpose of this invention is to provide a digital monitoring method and system for partial discharge, which solves the problems of inaccurate synchronization of power frequency phase, cable redundancy, and difficulty in multi-data fusion diagnosis in equipment monitoring systems.

[0004] The present invention solves the technical problem by adopting the following technical solution:

[0005] A digital monitoring method for partial discharge uses a digital sensor to collect partial discharge signals, obtains the real-time frequency of the power grid and converts it into the power frequency phase, and sends the partial discharge detection data containing the power frequency phase to the signal acquisition terminal through a PoE network cable, thereby synchronizing the digital voltage and frequency in real time.

[0006] Preferably, a partial discharge digital monitoring method and system includes: several wireless acquisition systems and an analysis and diagnosis backend, wherein the wireless acquisition systems respectively acquire partial discharge signals and are all wirelessly connected to the analysis and diagnosis backend;

[0007] The wireless acquisition system includes a power module, an acquisition module, and a signal acquisition terminal. The acquisition module acquires partial discharge signals and is connected to the signal acquisition terminal. The power module is connected to the signal acquisition terminal, and the signal acquisition terminal is wirelessly connected to the analysis and diagnosis backend.

[0008] Preferably, the signal acquisition terminal includes: a signal exchange module, a control module, a synchronization module, and a WIFI module. The synchronization module is connected to the signal exchange module, the signal exchange module is connected to the control module, the control module is connected to the analysis and diagnosis backend through the WIFI module, the signal exchange module is connected to the acquisition module, and the digital frequency calculation module is connected to the power supply.

[0009] Preferably, the synchronization module includes: a power conversion unit, an analog-to-digital conversion unit, and a digital frequency calculation unit. The power conversion unit is connected to the power module and the acquisition module, respectively. The analog-to-digital conversion unit is connected to the power supply and the control module, respectively. The digital frequency calculation unit is connected to the analog-to-digital conversion unit and the control module, respectively.

[0010] Preferably, the acquisition module includes a sensor daisy chain, which is connected to the signal exchange module, and the sensor types include ultra-high frequency sensors, high frequency sensors, and ultrasonic sensors.

[0011] Preferably, the power module includes a lithium battery and a 220V maintenance power supply.

[0012] Preferably, the analysis and diagnosis backend includes: a data storage module, a map recognition module, a positioning module, and an alarm module.

[0013] Preferably, the ultrasonic sensor, high-frequency sensor, and ultra-high-frequency sensor are cascaded in a series topology.

[0014] Preferably, the signal exchange module is provided with several interfaces, which are respectively connected to the ultrasonic sensor, the high-frequency sensor and the ultra-high-frequency sensor, as well as the synchronization module.

[0015] Preferably, the sensor daisy chain includes: a plurality of digital sensors connected in series, the digital sensors being connected to a signal exchange module and powered by a power supply module.

[0016] Preferably, the analysis and diagnosis backend and signal acquisition terminal are also equipped with 4G network terminals.

[0017] This invention utilizes a wireless acquisition system and a wireless analysis and diagnostic backend for wireless connection. Sensors are connected via a serial topology to reduce redundant wiring. Sensor signals are acquired and synchronized with the power grid frequency via UDP broadcast, achieving a closed loop of "precise synchronization - reliable transmission - intelligent operation and maintenance." This provides a data foundation with millimeter-level spatiotemporal accuracy for power equipment condition assessment. The 4G / WIFI unit ensures that partial discharge data is synchronously transmitted to the backend, supporting remote alarm and control. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0019] Figure 2 This is a schematic diagram of the structural connection of the present invention;

[0020] Figure 3 This is a schematic diagram of the module connection of the present invention;

[0021] The markings in the diagram are as follows: 1-Wireless acquisition system; 2-Analysis and diagnosis backend; 3-Power module; 4-Acquisition module; 5-Signal acquisition terminal; 6-Signal exchange module; 7-Control module; 8-Synchronization module; 9-WIFI module; 10-Sensor daisy chain; 11-Digital sensor; 12-4G network terminal. Detailed Implementation

[0022] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0023] A digital monitoring method for partial discharge uses a digital sensor to collect partial discharge signals, obtains the real-time frequency of the power grid and converts it into the power frequency phase, and sends the partial discharge detection data containing the power frequency phase to the signal acquisition terminal through a PoE network cable, thereby synchronizing the digital voltage and frequency in real time.

[0024] In a further implementation of this embodiment, during the signal acquisition stage, the digital sensor captures the partial discharge pulse signal at a sampling rate of 100MS / s and simultaneously acquires the 220V grid voltage waveform.

[0025] In a further implementation of this embodiment, during the frequency synchronization stage, the analog-to-digital converter converts the power grid analog signal into a 24-bit ADC, 10kHz sampled digital signal, which can achieve a power frequency phase synchronization accuracy of ±0.5μs.

[0026] In a further implementation of this embodiment, during the data transmission stage, the digital sensor binds and packages the partial discharge signal with the synchronization phase, and transmits it to the signal acquisition terminal via a PoE network cable.

[0027] In a further implementation of this embodiment, during real-time synchronization, the frequency broadcast is updated every 20ms power frequency cycle, the signal acquisition terminal verifies the time scale deviation, automatically compensates for transmission delay, and μs-level clock synchronization is achieved between multiple terminals using the IEEE 1588v2 protocol.

[0028] Example 2

[0029] A partial discharge digital monitoring system includes: several wireless acquisition systems 1 and an analysis and diagnosis backend 2. The multiple wireless acquisition systems 1 respectively acquire partial discharge signals and are all wirelessly connected to the analysis and diagnosis backend 2 to form a broadband wireless communication network.

[0030] The wireless acquisition system 1 includes: a power module 3, an acquisition module 4, and a signal acquisition terminal 5. The acquisition module 4 acquires partial discharge signals and is connected to the signal acquisition terminal 5 via a network cable. The power module 3 is connected to the signal acquisition terminal 5, and the signal acquisition terminal 5 is wirelessly connected to the analysis and diagnosis backend 2.

[0031] In a further embodiment of this invention, the signal acquisition terminal 5 includes: a signal exchange module 6, a control module 7, a synchronization module 8, and a WIFI module 9. The synchronization module 8 integrates a GPS / BeiDou dual-mode clock chip and is connected to the signal exchange module 6. The signal exchange module 6 is connected to the control module 7. The control module 7 is based on an ARM Cortex-M7 processor, runs a real-time operating system to schedule data acquisition tasks, and is connected to the analysis and diagnosis backend 2 through the WIFI module 9. The signal exchange module 6 is connected to the acquisition module 4, and the digital frequency calculation module is connected to the power supply.

[0032] The signal exchange module 6 is an Ethernet switch that connects to the sensor daisy chain 10 via an RJ45 interface. It has Ethernet power supply and switch communication functions, and is connected to DC power from the power module 3 to provide power to the sensor daisy chain 10. It can also be cascaded to the next sensor in the daisy chain. It forms a local area network with all the devices in the daisy chain, and receives and distributes partial discharge detection data, power frequency phase synchronization information, and control commands from the analysis and diagnosis background 2.

[0033] The signal exchange module 6 is configured with 8 dedicated interfaces. Interfaces 1-3 are connected to UHF, HF, and ultrasonic sensor chains, respectively. Interface 4 is used for the dedicated gigabit fiber optic interface of the synchronization module 8. Interfaces 5-6 are used for cascading adjacent signal acquisition terminals 5. Interfaces 7-8 are spare expansion interfaces.

[0034] Synchronization module 8 acquires and converts the real-time frequency of the power grid into power frequency phase synchronization. Based on the UDP network protocol, it sends the real-time frequency of the power grid in digital form to the digital sensor 11 of the sensor daisy chain 10 via network broadcast. Then, the digital sensor 11 sends the partial discharge detection data containing the power frequency phase to the signal acquisition terminal 5 via the POE network cable, thus realizing the real-time synchronization of digital voltage frequency (power frequency phase).

[0035] In a further embodiment of this invention, the synchronization module 8 includes: a power conversion unit, an analog-to-digital conversion unit, and a digital frequency calculation unit. The power conversion unit is connected to the power module 3 and the acquisition module 4, respectively, and converts the 220V maintenance power supply into a 48V DC power supply to provide continuous power to the sensor daisy chain 10. The analog-to-digital conversion unit is connected to the power supply and the control module 7, respectively, and uses a 24-bit high-precision ADC to capture the power grid waveform at a sampling rate of 10kHz, converting the 220V voltage sine wave analog signal into a digital signal. The digital frequency calculation module is connected to the analog-to-digital conversion module and the control module 7, respectively, and uses the FFT algorithm to filter and analyze the sine wave digital signal to calculate the power grid frequency in real time.

[0036] In a further embodiment of this example, the acquisition module 4 includes a sensor daisy chain 10, which is connected to the signal exchange module 6. The sensor types include ultra-high frequency sensors, high frequency sensors, and ultrasonic sensors.

[0037] In a further embodiment of this invention, the power module 3 includes a lithium battery and a 220V maintenance power supply. The lithium battery is used in the event of a sudden power outage to ensure that the equipment continues to operate for a period of time and to prevent data loss.

[0038] A further implementation of this embodiment analyzes and displays the data analysis results of the integrated diagnostic backend 2, and displays the GIS / GIL status monitoring results on the software interface and alarm devices, which can be viewed remotely. Specifically, it includes a data storage module, a map recognition module, a positioning module, and an alarm module. The data storage module stores partial discharge data received from the wireless acquisition system 1; the map recognition module analyzes the partial discharge map to identify the discharge type and severity; the positioning module locates the discharge source based on multi-sensor data fusion; and the alarm module triggers local and remote alarm devices when an anomaly is detected, and supports remote access via 4G / WIFI network, enabling maintenance personnel to view monitoring data and alarm information in real time.

[0039] In a further embodiment of this invention, the ultrasonic sensor daisy chain 10, the high-frequency sensor daisy chain 10, and the ultra-high frequency sensor daisy chain 10 are cascaded in series topology. The ultra-high frequency daisy chain spacing is ≤5m, and they are connected in series through an SMA interface. The coaxial cable length of the high-frequency daisy chain is ≤3m. The ultrasonic daisy chain is connected through a shielded twisted pair daisy chain. The end of the ultrasonic daisy chain is equipped with a 120Ω terminating resistor to ensure signal integrity.

[0040] In a further embodiment of this invention, the signal exchange module 6 is provided with several interfaces, which are respectively connected to the ultrasonic sensor, the high-frequency sensor, and the ultra-high-frequency sensor, as well as the synchronization module 8.

[0041] In a further embodiment of this invention, the sensor daisy chain 10 includes: a plurality of digital sensors 11 connected in series, the digital sensors being connected to the interface of the signal exchange module 6 and powered by a 220V maintenance power supply or a lithium battery; the synchronization module 8 is located in the signal acquisition terminal 5 and communicates with the analysis and diagnosis backend 2 via a wireless connection.

[0042] The background diagnostic backend, signal acquisition terminal 5, and all digital sensors 11 form a global detection network through wired and wireless integration. Power grid frequency phase information, partial discharge detection data, and control commands issued by the analysis and diagnostic backend 2 can all be transmitted and responded to in real time.

[0043] In a further implementation of this embodiment, the analysis and diagnosis backend 2 and the signal acquisition terminal 5 are also equipped with a 4G network terminal 12, which allows maintenance personnel to remotely access and view detection data and alarm information in real time.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A digital monitoring method for partial discharge, characterized in that, Partial discharge signals are acquired using digital sensors, the real-time frequency of the power grid is obtained and converted into the power frequency phase, and the partial discharge detection data containing the power frequency phase is sent to the signal acquisition terminal via a PoE network cable to synchronize the digital voltage and frequency in real time.

2. A partial discharge digital monitoring system, characterized in that, include: Several wireless acquisition systems and an analysis and diagnosis backend are provided. The wireless acquisition systems acquire partial discharge signals and are all wirelessly connected to the analysis and diagnosis backend. The wireless acquisition system includes a power module, an acquisition module, and a signal acquisition terminal. The acquisition module acquires partial discharge signals and is connected to the signal acquisition terminal. The power module is connected to the signal acquisition terminal, and the signal acquisition terminal is wirelessly connected to the analysis and diagnosis backend.

3. The partial discharge digital monitoring method and system according to claim 1, characterized in that, The signal acquisition terminal includes a signal exchange module, a control module, a synchronization module, and a WIFI module. The synchronization module is connected to the signal exchange module, the signal exchange module is connected to the control module, the control module is connected to the analysis and diagnosis backend through the WIFI module, the signal exchange module is connected to the acquisition module, and the digital frequency calculation module is connected to the power supply.

4. The partial discharge digital monitoring method and system according to claim 3, characterized in that, The synchronization module includes a power conversion unit, an analog-to-digital conversion unit, and a digital frequency calculation unit. The power conversion unit is connected to the power module and the acquisition module, the analog-to-digital conversion unit is connected to the power supply and the control module, and the digital frequency calculation unit is connected to the analog-to-digital conversion unit and the control module.

5. The partial discharge digital monitoring method and system according to claim 3, characterized in that, The acquisition module includes a sensor daisy chain, which is connected to the signal exchange module. The sensor types include ultra-high frequency sensors, high frequency sensors, and ultrasonic sensors.

6. The partial discharge digital monitoring method and system according to claim 1, characterized in that, The power module includes a lithium battery and a 220V maintenance power supply.

7. The partial discharge digital monitoring method and system according to claim 1, characterized in that, The analysis and diagnosis backend includes: a data storage module, a map recognition module, a positioning module, and an alarm module.

8. The partial discharge digital monitoring method and system according to claim 5, characterized in that, The ultrasonic sensor, high-frequency sensor, and ultra-high-frequency sensor are cascaded in a series topology.

9. The partial discharge digital monitoring method and system according to claim 5, characterized in that, The signal exchange module is equipped with several interfaces, which are respectively connected to the ultrasonic sensor, the high-frequency sensor, the ultra-high-frequency sensor, and the synchronization module.

10. The partial discharge digital monitoring method and system according to claim 5, characterized in that, The sensor daisy chain includes: several digital sensors connected in series, which are connected to a signal exchange module and powered by a power supply module.

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