Electrical equipment insulation on-line monitoring device

Abstract

The invention belongs to the technical field of electrical equipment state monitoring, and particularly relates to an electrical equipment insulation online monitoring device which comprises a shell, a power module, a multi-parameter sensing interface unit, a synchronous acquisition unit, an edge processing unit and a communication unit. The power supply module is positioned in the shell; the multi-parameter sensing interface unit is used for connecting and receiving analog and digital signals from external sensors, and the external sensors comprise a dielectric loss monitoring sensor, a partial discharge sensor, an insulation resistance monitoring sensor and an environment temperature and humidity sensor; the synchronous acquisition unit is used for performing synchronous analog-to-digital conversion on multiple paths of analog signals and providing a unified time base for data acquisition of all channels; the edge processing unit is used for carrying out processing, feature extraction and insulation state analysis on the collected data; and the communication unit is used for transmitting data and diagnosis results of the device to the outside, so that the problems of high false alarm rate, single function and low intelligent degree in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of power equipment condition monitoring technology, and in particular to an online insulation monitoring device for electrical equipment. Background Technology

[0002] The insulation condition of electrical equipment is a key factor determining its operational reliability. Traditional preventive testing and periodic maintenance are lagging and may fail to detect potential insulation defects in a timely manner. Existing online monitoring devices mostly use single-parameter monitoring (such as monitoring only dielectric loss or partial discharge), which has the following shortcomings:

[0003] High false alarm rate: Single parameters are easily affected by on-site electromagnetic interference, ambient temperature, humidity and operating load, resulting in unreliable diagnostic results;

[0004] Single function: Different monitoring projects often require independent devices, which are costly and complex.

[0005] Low level of intelligence: Most devices only collect and upload data, lack on-site analysis and diagnosis capabilities, and alarm thresholds are mostly fixed values, unable to adapt to changing working conditions;

[0006] Therefore, there is an urgent need for an integrated, intelligent online monitoring device capable of comprehensive multi-parameter analysis to improve the accuracy and reliability of insulation condition assessment. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide an online monitoring device for electrical equipment insulation that is highly integrated, has strong anti-interference capabilities, and provides accurate diagnostics.

[0008] This invention proposes an online insulation monitoring device for electrical equipment, comprising: a housing, a power module, a multi-parameter sensing interface unit, a synchronous acquisition unit, an edge processing unit, and a communication unit. The power module, located within the housing, supplies power to the entire device. The multi-parameter sensing interface unit connects to and receives analog and digital signals from external sensors, including dielectric loss monitoring sensors, partial discharge sensors, insulation resistance monitoring sensors, and environmental temperature and humidity sensors. The synchronous acquisition unit, electrically connected to the multi-parameter sensing interface unit, performs synchronous analog-to-digital conversion on multiple analog signals. It has a built-in or external high-precision clock source to provide a unified time base for data acquisition across all channels. The edge processing unit, electrically connected to the synchronous acquisition unit, includes a microprocessor and a memory. The memory stores a computer program, which, when executed by the microprocessor, processes the acquired data, extracts features, and analyzes the insulation status. The communication unit, electrically connected to the edge processing unit, transmits the device's data and diagnostic results externally.

[0009] Preferably, the edge processing unit is configured to perform multi-parameter fusion analysis, specifically including: performing time alignment and correlation analysis on dielectric loss angle variation data, partial discharge characteristic data, and insulation resistance data to cross-validate the diagnostic conclusions of insulation status.

[0010] Preferably, the edge processing unit is further configured to dynamically adjust the reference values ​​of the dielectric loss angle and insulation resistance alarm threshold based on the ambient temperature and humidity data collected by the received ambient temperature and humidity sensor and the equipment operating voltage data obtained through the operating parameter interface.

[0011] Preferably, the high-precision clock source used in the synchronous acquisition unit is a BeiDou satellite synchronization module or a high-stability constant-temperature crystal oscillator.

[0012] Preferably, the multi-parameter sensing interface unit includes: a dielectric loss measurement interface for connecting a through-core current sensor or obtaining signals from the end screen of equipment such as transformers; a partial discharge measurement interface, including a high-frequency current transformer interface and an ultra-high frequency sensor interface; an insulation resistance measurement interface for connecting a DC superposition method or a low-frequency AC method measurement circuit; an ambient temperature and humidity measurement interface, using a digital or analog interface, for connecting a temperature and humidity sensor; and an equipment operating parameter interface for obtaining operating voltage and current data of equipment such as transformers from station control layer equipment via RS-485 or Ethernet.

[0013] Preferably, the communication unit supports at least one of the following communication protocols: IEC61850, MQTT, Modbus TCP / IP or 4G / 5G wireless transmission protocol, and the communication unit may include a 4G communication module.

[0014] Preferably, the memory of the edge processing unit also stores a lightweight neural network model for pattern recognition and preliminary fault type classification of the PRPD spectrum generated by partial discharge.

[0015] Preferably, the device further includes a local human-machine interface, which includes an LCD touch screen and buttons for displaying monitoring data and device status locally.

[0016] Compared with the prior art, the present invention provides an online insulation monitoring device for electrical equipment, which has the following beneficial effects:

[0017] 1. Integration: Multiple monitoring functions are integrated into one device, simplifying the system structure and reducing costs.

[0018] 2. Synchronization: High-precision synchronous sampling ensures the consistency of different parameter data over time, laying a solid foundation for subsequent fusion analysis.

[0019] 3. Intelligent: The device has edge computing capabilities, which can complete complex data analysis and diagnosis on-site, reducing the burden on the upper-level system and improving the response speed.

[0020] 4. Reliability: Through multi-parameter fusion analysis and dynamic threshold adjustment, the limitations of single-parameter monitoring are effectively overcome, and the accuracy and anti-interference ability of insulation condition diagnosis are significantly improved. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the installation and application of an online insulation monitoring device for electrical equipment proposed in this invention within a monitoring system.

[0022] Figure 2 This is a hardware structure block diagram of an online insulation monitoring device for electrical equipment proposed in this invention;

[0023] Figure 3 This is a flowchart illustrating the internal data processing of an online insulation monitoring device for electrical equipment proposed in this invention.

[0024] Figure 4 This is a schematic diagram of the front panel of one embodiment of an online insulation monitoring device for electrical equipment proposed in this invention.

[0025] In the diagram: 1. This device; 2. Transformer; 3. End-screen current sensor; 4. UHF sensor; 5. Temperature and humidity sensor; 6. Local area network within the station; 7. Local monitoring center or remote cloud platform; 101. Power module; 102. Multi-parameter sensing interface unit; 103. Synchronous acquisition unit; 104. Edge processing unit; 105. Communication unit; 106. Human-machine interface; 102a. Dielectric loss measurement interface; 102b. Partial discharge measurement interface; 102c. Insulation resistance measurement interface; 102d. Ambient temperature and humidity measurement interface; 102e. Operating parameter interface; 103a. High-precision clock source; 104a. Memory; 105a. 4G communication module; 106a. LCD touch screen; 106b. Buttons. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] See Figure 1 The device 1 is installed at the substation site and connects to various external sensors through a multi-parameter sensing interface unit, including: a screen current sensor 3 for monitoring the bushing insulation of transformer 2, a partial discharge sensor (UHF sensor 4) for monitoring partial discharge of transformer 2, and a temperature and humidity sensor 5 installed on site; at the same time, the device 1 connects to the local area network 6 of the station through the communication unit 105 and can upload data to the local monitoring center or remote cloud platform 7.

[0029] See Figure 2 The hardware structure of the online insulation monitoring device for electrical equipment includes:

[0030] Power module 101: It adopts a wide AC / DC voltage input (AC / DC 85-265V) and has a built-in backup battery to ensure power supply reliability;

[0031] Multi-parameter sensing interface unit 102: provides a variety of dedicated interfaces;

[0032] Dielectric loss measurement interface 102a: provides a BNC or LEMO interface for through-core current sensors, with a weak current signal as the input signal;

[0033] Partial discharge measurement interface 102b: includes HFCT interface (for cable connectors, etc.) and UHF interface (SMA type, for GIS or transformers);

[0034] Insulation resistance measurement interface 102c: provides wiring terminals for connection to a DC overlay unit or direct sampling;

[0035] 102d Ambient temperature and humidity sensor interface: Uses RS-485 or I2C digital interface to connect to digital temperature and humidity probe;

[0036] Equipment operating parameter interface 102e: adopts RS-485 interface, and reads real-time voltage and current values ​​from the station control system via Modbus protocol;

[0037] Synchronous acquisition unit 103: Its core is a multi-channel synchronous acquisition ADC chip (such as AD7606); the high-precision clock source 103a adopts a high-stability temperature-controlled crystal oscillator (OCXO) to provide a stable sampling clock with extremely low jitter for the ADC; the sampling time of all channels is strictly synchronized with an error of less than 1 nanosecond;

[0038] Edge processing unit 104: adopts an architecture of "ARM Cortex-A series core processor (such as TI's AM57xx) + FPGA"; the FPGA is responsible for high-speed data transfer and preprocessing (such as digital filtering), and the ARM core processor is responsible for running the embedded Linux operating system and the main analysis program; the memory 104a includes DDR3 memory and eMMCFlash for storing programs and data.

[0039] Communication unit 105: includes a gigabit Ethernet PHY chip, supporting IEC61850MMS and GOOSE protocols; it can also be equipped with an optional 4G communication module 105a to realize wireless transmission;

[0040] Human-machine interface 106: includes an LCD touch screen 106a and several buttons 106b, used for local display of waveforms, data, alarm information and parameter settings;

[0041] See Figure 3 The data processing flow inside the electrical equipment insulation online monitoring device is as follows:

[0042] Step 1, Data Synchronous Acquisition (S101): Under the drive of the OCXO clock, the synchronous acquisition unit 103 synchronously acquires the analog and digital signals of all interfaces;

[0043] Step 2, Signal Preprocessing (S102): The FPGA preprocesses the original signal, such as power frequency cycle integration, digital filtering, pulse counting, etc.

[0044] Step 3, Feature Extraction (S103): The ARM processor calculates various feature quantities, such as: dielectric loss angle (tanδ) and capacitance (C), partial discharge quantity, discharge number, PRPD spectrum statistical characteristics, insulation resistance value, ambient temperature and humidity value, etc.

[0045] Step 4, Multi-parameter Fusion Analysis and Diagnosis (S104): This is the core step; the processor calls the program in memory and executes it.

[0046] 1. Time alignment: Ensure that the timestamps of all features are consistent;

[0047] 2. Correlation analysis: For example, if a decrease in insulation resistance is found and an increase in ambient humidity is detected at the same time, it may be judged as dampness; if a decrease in insulation resistance is accompanied by a sharp increase in partial discharge activity, it may be judged as the early stage of insulation aging and breakdown; through multi-parameter cross-validation, a more reliable diagnostic conclusion can be obtained (S105).

[0048] 3. Dynamic threshold adjustment: Based on the current ambient humidity, automatically query the preset humidity-threshold comparison table and adjust the dielectric loss alarm threshold;

[0049] Step 5, Result Output and Transmission (S106): Package the diagnostic results, characteristic data and original waveforms (if an alarm is triggered) in IEC61850 format and upload them to the monitoring system through communication unit 105.

[0050] Working principle:

[0051] In use, the power module 101 powers the entire electrical equipment insulation online monitoring device. The multi-parameter sensing interface unit 102 connects to corresponding external devices and sensors through its included dielectric loss measurement interface 102a, partial discharge measurement interface 102b, insulation resistance measurement interface 102c, ambient temperature and humidity measurement interface 102d, and operating parameter interface 102e. Specifically, the dielectric loss measurement interface 102a connects to the end-screen current sensor 3 to obtain dielectric loss related signals from electrical equipment such as the transformer 2; the partial discharge measurement interface 102b connects to the UHF sensor 4 to obtain partial discharge signals; the insulation resistance measurement interface 102c connects to the insulation resistance monitoring sensor; the ambient temperature and humidity measurement interface 102d connects to the temperature and humidity sensor 5; and the operating parameter interface 102e obtains information about the transformer 2 from the station control layer equipment via RS-485 or Ethernet. The system processes voltage and current data. The multi-parameter sensing interface unit 102 receives the analog and digital signals and transmits them to the synchronous acquisition unit 103. The synchronous acquisition unit 103 uses a high-precision clock source 103a to perform synchronous analog-to-digital conversion on multiple analog signals. The converted data is then transmitted to the edge processing unit 104. The microprocessor of the edge processing unit 104 calls the computer program in the memory 104a to process the data, extract features, and analyze insulation status. The analysis results and related data are transmitted via the communication unit 105 to the local area network 6 according to the supported communication protocol, and then uploaded to the local monitoring center or remote cloud platform 7. Simultaneously, the local human-machine interface 106 displays the monitoring data and device status locally via the LCD touchscreen 106a and buttons 106b, realizing online monitoring and diagnosis of the insulation status of electrical equipment.

[0052] In summary, the device of the present invention integrates multiple monitoring functions, and through hardware synchronization and software fusion analysis, it significantly improves the accuracy and reliability of online monitoring of electrical equipment insulation.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An online insulation monitoring device for electrical equipment, characterized in that, include: The device comprises a housing, a power module (101), a multi-parameter sensing interface unit (102), a synchronous acquisition unit (103), an edge processing unit (104), and a communication unit (105). The power module (101) is located inside the housing and is used to power the entire device. The multi-parameter sensing interface unit (102) is used to connect to and receive analog and digital signals from external sensors, including a dielectric loss monitoring sensor, a partial discharge sensor, an insulation resistance monitoring sensor, and an ambient temperature and humidity sensor (5). The synchronous acquisition unit (103) is electrically connected to the multi-parameter sensing interface unit (102) and is used to process multiple signals. The analog signal undergoes synchronous analog-to-digital conversion, and it has a built-in or external high-precision clock source (103a) to provide a unified time base for data acquisition of all channels; the edge processing unit (104) is electrically connected to the synchronous acquisition unit (103), and it includes a microprocessor and a memory (104a). The memory (104a) stores a computer program, which is used to process the acquired data, extract features, and analyze insulation status when executed by the microprocessor; the communication unit (105) is electrically connected to the edge processing unit (104) and is used to transmit the device's data and diagnostic results to the outside world.

2. The online insulation monitoring device for electrical equipment according to claim 1, characterized in that, The edge processing unit (104) is configured to perform multi-parameter fusion analysis, specifically including: performing time alignment and correlation analysis on dielectric loss angle change data, partial discharge characteristic data, and insulation resistance data to cross-validate the diagnostic conclusions of insulation status.

3. The online insulation monitoring device for electrical equipment according to claim 2, characterized in that, The edge processing unit (104) is also configured to dynamically adjust the reference values ​​of the dielectric loss angle and insulation resistance alarm threshold based on the ambient temperature and humidity data collected by the received ambient temperature and humidity sensor (5) and the equipment operating voltage data obtained through the operating parameter interface (102e).

4. The online insulation monitoring device for electrical equipment according to claim 1, characterized in that, The high-precision clock source (103a) used by the synchronous acquisition unit (103) is a GPS / BeiDou satellite synchronization module or a high-stability constant-temperature crystal oscillator.

5. The online insulation monitoring device for electrical equipment according to claim 1, characterized in that, The multi-parameter sensing interface unit (102) includes: a dielectric loss measurement interface (102a) for connecting a through-core current sensor or obtaining signals from the end screen of equipment such as the transformer (2); a partial discharge measurement interface (102b) including a high-frequency current transformer interface and an ultra-high frequency sensor (4) interface; an insulation resistance measurement interface (102c) for connecting a DC superposition method or a low-frequency AC method measurement circuit; an ambient temperature and humidity measurement interface (102d) using a digital or analog interface for connecting a temperature and humidity sensor (5); and an equipment operation parameter interface (102e) for obtaining the operating voltage and current data of equipment such as the transformer (2) from the station control layer equipment via RS-485 or Ethernet.

6. The online insulation monitoring device for electrical equipment according to claim 1, characterized in that, The communication unit (105) supports at least one of the following communication protocols: IEC61850, MQTT, Modbus TCP / IP or 4G / 5G wireless transmission protocol, and the communication unit (105) may include a 4G communication module (105a).

7. The online insulation monitoring device for electrical equipment according to claim 1, characterized in that, The edge processing unit (104) also stores a lightweight neural network model in its memory (104a) for pattern recognition and preliminary fault type classification of the PRPD spectrum generated by partial discharge.

8. The online insulation monitoring device for electrical equipment according to claim 1, characterized in that, The device also includes a local human-machine interface (106), which includes an LCD touch screen (106a) and buttons (106b) for displaying monitoring data and device status locally.

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