Multi-partial discharge wireless online monitoring method and system

Abstract

The invention relates to the technical field of power equipment monitoring, in particular to a multi-partial discharge wireless online monitoring method and system, which comprises a server, a mobile phone terminal monitor, a signal acquisition module, a communication controller, a user interface, a monitoring early warning and a communication circuit design. The on-line monitoring system provided by the invention develops a three-in-one wireless partial discharge sensor which can stably work for a long time in an electrified operation state of equipment and in high and low temperature environments aiming at a partial discharge phenomenon caused by factors such as material aging, poor contact and current overload at a contact part of the electrical equipment and a fault hidden danger which is not easy to detect; the device has the advantages of small size, light weight, capability of live installation, reduced wiring and installation cost, wide application scene range, high adaptability and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment monitoring, and in particular to a method and system for wireless online monitoring of multiple partial discharges. Background Art

[0002] There are many primary devices in the power system, including transformers, capacitors, reactors, and various distribution cabinets. In the power distribution process of the power system, the above equipment plays an important role, and their stability is related to the stability of users' power consumption. In actual operation, distribution equipment is often affected by various environmental interferences. For example, high temperature can easily cause insulation aging or even damage of the equipment, high humidity can easily cause surface discharge of equipment insulation, and overload can also affect the performance of the equipment. Among these, the most likely to occur is partial discharge of the equipment.

[0003] The existing methods for detecting partial discharge of power equipment include ultrasonic detection method, TEV detection method, etc. The handheld partial discharge detectors on the market have high enough detection sensitivity, but they are mostly used by the operation and maintenance personnel of the power system during the annual spring inspection, autumn inspection or routine inspection, and cannot obtain real-time monitoring data of power equipment. At the same time, it is difficult for handheld partial discharge detectors to track the long-term discharge of a certain power equipment.

[0004] In order to make up for the above-mentioned shortcomings of handheld partial discharge detectors, this project comprehensively applies high-frequency partial discharge, ultra-high frequency partial discharge detection, transient ground voltage and ultrasonic detection to partial discharge detection of power equipment, and develops partial discharge online monitoring sensors based on ultrasonic, ultra-high frequency and TEV combined technology. Its main advantage is that it realizes online monitoring of partial discharge, can timely detect early partial discharge phenomena of power equipment, and can save long-term discharge monitoring data of power equipment. Based on these data, operation and maintenance personnel can understand the health status of the equipment, and then repair or replace it. A multi-partial discharge wireless online monitoring method and system is needed to solve this problem. Summary of the invention

[0005] The object of the present invention is to provide a method and system for wireless online monitoring of multiple partial discharges to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned object, the present invention provides the following technical solutions: a wireless online monitoring system for multiple partial discharges, including a server, a mobile terminal monitoring, a signal acquisition module, a communication control, a user interface, a monitoring warning and a communication circuit design; The server is respectively connected to the mobile terminal monitoring and signal acquisition modules, the server is connected to the communication control, the server is connected to the user interface, the server is connected to the monitoring warning, and the server is connected to the communication circuit design.

[0007] As a preferred technical solution of the present invention, the signal acquisition module is divided into A / D conversion and a main controller. The A / D conversion is mainly divided into converting the acoustic emission voltage signal into a digital signal to facilitate signal processing and transmission, while the main controller processes the acoustic emission signal into acoustic emission characteristic parameters.

[0008] As a preferred technical solution of the present invention, the communication control is connected to an on-site discharge detection unit array, wherein the on-site discharge detection unit array helps power operation and maintenance personnel to timely understand the equipment operation status and discover insulation defects of the switch cabinet.

[0009] As the preferred technical solution of the present invention, the A / D conversion chip realizes the conversion of the acoustic emission voltage analog signal into a digital signal, and is an important component of the signal acquisition system. Its sampling rate and sampling accuracy determine the integrity and accuracy of the collected signal. This project uses a UHF antenna to sense the electromagnetic wave signal in the switch cabinet, and an ultrasonic sensor to sense the vibration of the ultrasonic signal transmitted by the discharge source. According to the characteristics of the ultrasonic signal generated by partial discharge, the frequency range is 20kHz~300kHz. According to the sampling law and system design requirements, the signal sampling rate range should be 1MHz~2MHz. The AD conversion chip should have a higher sampling rate and a sampling accuracy of 16 bits. The data bus interface of the AD conversion chip has a serial mode and a parallel mode. Compared with the serial data output mode, the parallel data output mode has a higher sampling rate.

[0010] As a preferred technical solution of the present invention, the key point of the partial discharge generation of ultrasonic vibration signals, ultra-high frequency electromagnetic wave signals and transient ground voltage collection and data transmission system designed by the communication circuit is the high-speed signal collection and rapid transmission of large quantities of data.

[0011] As the preferred technical solution of the present invention, the partial discharge sensor designed by the communication circuit obtains ultrasonic information of substation equipment and transient ground voltage partial discharge information, and the ultra-high frequency partial discharge sensor obtains ultra-high frequency partial discharge information of switchgear to realize data collection, data storage, monitoring table, trend query, database record, alarm information, equipment information, setting, SMS reminder and other functions.

[0012] A method for wireless online monitoring of multiple partial discharges, characterized in that it comprises the following steps: S1. Before monitoring, first keep the surface of the switch cabinet and transformer-related power equipment clean and dry to prevent the insulation surface from being damp or contaminated. Before use, it needs to be closed and left to stand for a period of time to prevent the switch cabinet and transformer from having just been used and residual electricity and heat that affect the results of subsequent monitoring. S2. Before applying voltage, test the test circuit to ensure that no partial discharge occurs at a test voltage slightly higher than that of the product under test. If the partial discharge interference level exceeds or approaches 50% of the maximum allowable discharge capacity value of the test product, the source of interference must be identified and measures must be taken to reduce the interference level; S3. During the monitoring process, transient voltage detection and ultrasonic detection are used to perform threshold, horizontal and vertical analysis on the switchgear and transformer-related power equipment, and preliminary diagnosis is performed. The auxiliary UHF detection method can effectively suppress electromagnetic interference and improve the sensitivity of detection. It can obtain information from multiple angles and levels to adapt to different environments and equipment. S4. Through ultrasonic, transient ground voltage and UHF comprehensive verification, the five-in-one partial discharge comprehensive detection sensor detection of power equipment discharge is the first step in the insulation fault monitoring and verification of power equipment such as high-voltage switchgear and transformers. The electrical signal output by the partial discharge composite sensor is converted into a digital signal after processing, and then transmitted and further calculated; S5. The partial discharge online monitoring system will be able to realize the detection, identification and positioning functions. Through the signal processing process, it will identify the type of defect and give the location of the defect, and conduct power outage inspection and experimental analysis, and quickly find out the cause of the fault, and send this information as an alarm message to the detection system monitor terminal and the management personnel's mobile terminal; S6. Power equipment adopts joint detection technology that mainly uses transient ground voltage and ultrasonic detection and is supplemented by ultra-high frequency detection. By organically combining the three for joint detection, the efficiency and accuracy of detection can be improved in different scenarios, and the advantages can be complementary. It can collect on-site data in all directions, accurately grasp the status of equipment, and has a wider range of applications.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention is a method and system for wireless online monitoring of multiple partial discharges. The online monitoring system provided by the present invention targets partial discharge phenomena caused by material aging, poor contact, current overload and other factors at the contact points of electrical equipment, and hidden faults that are difficult to detect. A three-in-one wireless partial discharge sensor is developed that can work stably for a long time when the equipment is powered on and in high and low temperature environments. The sensor has the advantages of small size, light weight, and can be installed under power, reducing wiring and installation costs, and having a wide range of application scenarios and strong adaptability.

[0014] (2) The present invention is a multi-partial discharge wireless online monitoring method and system. The project innovation of the online monitoring method provided by the present invention is to use ultra-high frequency, ultrasonic wave, transient ground wave, ambient temperature, and ambient humidity five-in-one comprehensive online monitoring technology, and combine the use of microelectronics technology and sensor low-power technology to achieve comprehensive online monitoring and alarm of hidden dangers of operation failures of electrical equipment such as transformers, ring network cabinets, and distribution boxes. The sensor life is greater than 10 years, the product is safe and reliable, easy to deploy, and maintenance-free BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a joint detection flow chart of a method for wireless online monitoring of multiple partial discharges according to an embodiment of the present invention; Figure 2 It is a schematic diagram of the structure of an online detection scheme of a method for wireless online monitoring of multiple partial discharges according to an embodiment of the present invention; Figure 3 The system block diagram of a multi-partial discharge wireless online monitoring system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0018] Example 1

[0019] refer to Figure 1 to Figure 2 Embodiment 1 is described, a method for wireless online monitoring of multiple partial discharges, characterized in that it comprises the following steps: S1. Before monitoring, first keep the surface of the switch cabinet and transformer-related power equipment clean and dry to prevent the insulation surface from being damp or contaminated. Before use, it needs to be closed and left to stand for a period of time to prevent the switch cabinet and transformer from having just been used and residual electricity and heat that affect the results of subsequent monitoring. S2. Before applying voltage, test the test circuit to ensure that no partial discharge occurs at a test voltage slightly higher than that of the product under test. If the partial discharge interference level exceeds or approaches 50% of the maximum allowable discharge capacity value of the test product, the source of interference must be identified and measures must be taken to reduce the interference level; S3. During the monitoring process, transient voltage detection and ultrasonic detection are used to perform threshold, horizontal and vertical analysis on the switchgear and transformer-related power equipment, and preliminary diagnosis is performed. The auxiliary UHF detection method can effectively suppress electromagnetic interference and improve the sensitivity of detection. It can obtain information from multiple angles and levels to adapt to different environments and equipment. S4. Through ultrasonic, transient ground voltage and UHF comprehensive verification, the five-in-one partial discharge comprehensive detection sensor detection of power equipment discharge is the first step in the insulation fault monitoring and verification of power equipment such as high-voltage switchgear and transformers. The electrical signal output by the partial discharge composite sensor is converted into a digital signal after processing, and then transmitted and further calculated; S5. The partial discharge online monitoring system will be able to realize the detection, identification and positioning functions. Through the signal processing process, it will identify the type of defect and give the location of the defect, and conduct power outage inspection and experimental analysis, and quickly find out the cause of the fault, and send this information as an alarm message to the detection system monitor terminal and the management personnel's mobile terminal; S6. Power equipment adopts joint detection technology that mainly uses transient ground voltage and ultrasonic detection and is supplemented by ultra-high frequency detection. By organically combining the three for joint detection, the efficiency and accuracy of detection can be improved in different scenarios, and the advantages can be complementary. It can collect on-site data in all directions, accurately grasp the status of equipment, and has a wider range of applications.

[0020] Example 2

[0021] refer to Figure 3 Example 2 is described. This embodiment further describes Example 1, including a server, mobile terminal monitoring, a signal acquisition module, a communication control, a user interface, a monitoring warning, and a communication circuit design; The server is respectively connected to the mobile terminal monitoring and signal acquisition module, the server is connected to the communication control, the server is connected to the user interface, the server is connected to the monitoring warning, and the server is connected to the communication circuit design; Among them, the signal acquisition module is divided into A / D conversion and main controller. A / D conversion is mainly divided into converting the acoustic emission voltage signal into a digital signal to facilitate the processing and transmission of the signal. The main controller processes the acoustic emission signal into acoustic emission characteristic parameters, including: ring count, rise time, amplitude, energy and effective voltage value, which are uploaded to the server through PCI bus or network communication. The communication control is connected to the field discharge detection unit array, where the field discharge detection unit array helps power operation and maintenance personnel to understand the equipment operation status in time and find insulation defects in the switch cabinet. The A / D conversion chip realizes the conversion of the acoustic emission voltage analog signal into a digital signal, which is an important part of the signal acquisition system. Its sampling rate and sampling accuracy determine the integrity and accuracy of the collected signal. This project uses a UHF antenna to sense the electromagnetic wave signal in the switch cabinet, and an ultrasonic sensor to sense the vibration of the ultrasonic signal transmitted by the discharge source. According to the characteristics of the ultrasonic signal generated by partial discharge, the frequency range is 20kHz~300kHz. According to the sampling law and system design requirements, the signal sampling rate range should be 1MHz~2MHz. The AD conversion chip should have a higher sampling rate and a sampling accuracy of 16 bits. The data bus interface of the AD conversion chip has serial mode and parallel mode. Compared with the serial data output mode, the parallel data output mode has a higher sampling rate. Therefore, choosing a bus interface chip with a parallel data output mode can greatly improve the sampling rate of the signal. There are three main types of AD converters according to the principle, namely successive comparison type, integral type and Σ-Δ modulation type. The Σ-Δ modulation type has good linearity, but its conversion speed is not very fast. The dual integral type has strong anti-interference ability and high conversion accuracy, but the conversion speed is relatively slow. The successive approximation AD converter has the advantages of high conversion accuracy, low noise, and fast conversion speed. This type of chip can be selected as the analog converter for this project. The key point of the partial discharge designed by the communication circuit to generate ultrasonic vibration signals, ultra-high frequency electromagnetic wave signals, and transient ground voltage collection and data transmission system lies in the high-speed signal collection and rapid transmission of large quantities of data. The partial discharge sensor designed by the communication circuit obtains the ultrasonic information of the substation equipment and the transient ground voltage partial discharge information, and the ultra-high frequency partial discharge sensor obtains the ultra-high frequency partial discharge information of the switch equipment to realize data collection, data storage, monitoring tables, trend queries, database records, alarm information, equipment information, settings, SMS reminders and other functions. The platform provides queries on the original collected data information, and forms various reports on years, months, and days through calculations.

[0022] Among them, the combined use of multiple live detection technologies can timely discover equipment defects and accurately diagnose and locate them. It can comprehensively and effectively diagnose and troubleshoot insulation faults of power equipment such as switch cabinets, transformers, and capacitors, and can efficiently guide the development of maintenance work to ensure the safe and stable operation of equipment. The three-in-one wireless partial discharge joint monitoring device developed in this project can realize real-time and comprehensive monitoring and analysis of key parameters of the operating status of power equipment, replace operating personnel to complete patrol work such as continuous status monitoring, defect detection and early warning, and patrol environment assessment, effectively solve the drawbacks of traditional patrol mode, reduce operation and maintenance costs, and improve the intelligent operation and maintenance level of substation equipment. It has high promotion and application value and broad market prospects.

[0023] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top", "bottom", "one side", "the other side", "front", "back", "middle part", "inside", "top end", "bottom end", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wireless online monitoring system for multiple partial discharges, characterized in that: Including server, mobile terminal monitoring, signal acquisition module, communication control, user interface, monitoring warning and communication circuit design; The server is respectively connected to the mobile terminal monitoring and signal acquisition modules, the server is connected to the communication control, the server is connected to the user interface, the server is connected to the monitoring warning, and the server is connected to the communication circuit design.

2. A wireless online monitoring system for multiple partial discharges according to claim 1, characterized in that: The signal acquisition module is divided into A / D conversion and a main controller. The A / D conversion is mainly divided into converting the acoustic emission voltage signal into a digital signal to facilitate signal processing and transmission, while the main controller processes the acoustic emission signal into acoustic emission characteristic parameters.

3. A wireless online monitoring system for multiple partial discharges according to claim 1, characterized in that: The communication control is connected to an array of on-site discharge detection units, wherein the array of on-site discharge detection units helps power operation and maintenance personnel to timely understand the operating status of the equipment and discover insulation defects of the switch cabinet.

4. A wireless online monitoring system for multiple partial discharges according to claim 1, characterized in that: The A / D conversion chip converts the acoustic emission voltage analog signal into a digital signal, and is an important part of the signal acquisition system. Its sampling rate and sampling accuracy determine the integrity and accuracy of the collected signal. This project uses a UHF antenna to sense the electromagnetic wave signal in the switch cabinet, and an ultrasonic sensor to sense the vibration of the ultrasonic signal transmitted by the discharge source. According to the characteristics of the ultrasonic signal generated by partial discharge, the frequency range is 20kHz~300kHz. According to the sampling law and system design requirements, the signal sampling rate range should be 1MHz~2MHz. The AD conversion chip should have a higher sampling rate and a sampling accuracy of 16 bits. The data bus interface of the AD conversion chip has serial mode and parallel mode. Compared with the serial data output mode, the parallel data output mode has a higher sampling rate.

5. The wireless online monitoring system for multiple partial discharges according to claim 1 is characterized in that: The key point of the partial discharge generation of ultrasonic vibration signals, ultra-high frequency electromagnetic wave signals and transient ground voltage collection and data transmission system designed by the communication circuit is the high-speed signal collection and rapid transmission of large quantities of data.

6. The wireless online monitoring system for multiple partial discharges according to claim 1 is characterized in that: The partial discharge sensor designed by the communication circuit obtains ultrasonic information of substation equipment and transient ground voltage partial discharge information, and the ultra-high frequency partial discharge sensor obtains ultra-high frequency partial discharge information of switchgear to realize data collection, data storage, monitoring table, trend query, database record, alarm information, equipment information, setting, SMS reminder and other functions; A method for wireless online monitoring of multiple partial discharges, characterized in that it comprises the following steps: S1. Before monitoring, first keep the surface of the switch cabinet and transformer-related power equipment clean and dry to prevent the insulation surface from being damp or contaminated. Before use, it needs to be closed and left to stand for a period of time to prevent the switch cabinet and transformer from having just been used and residual electricity and heat that affect the results of subsequent monitoring. S2. Before applying voltage, test the test circuit to ensure that no partial discharge occurs at a test voltage slightly higher than that of the product under test. If the partial discharge interference level exceeds or approaches 50% of the maximum allowable discharge capacity value of the test product, the source of interference must be identified and measures must be taken to reduce the interference level; S3. During the monitoring process, transient voltage detection and ultrasonic detection are used to perform threshold, horizontal and vertical analysis on the switchgear and transformer-related power equipment, and preliminary diagnosis is performed. The auxiliary UHF detection method can effectively suppress electromagnetic interference and improve the sensitivity of detection. It can obtain information from multiple angles and levels to adapt to different environments and equipment. S4. Through ultrasonic, transient ground voltage and UHF comprehensive verification, the five-in-one partial discharge comprehensive detection sensor detection of power equipment discharge is the first step in the insulation fault monitoring and verification of power equipment such as high-voltage switchgear and transformers. The electrical signal output by the partial discharge composite sensor is converted into a digital signal after processing, and then transmitted and further calculated; S5. The partial discharge online monitoring system will be able to realize the detection, identification and positioning functions. Through the signal processing process, it will identify the type of defect and give the location of the defect, and conduct power outage inspection and experimental analysis, and quickly find out the cause of the fault, and send this information as an alarm message to the detection system monitor terminal and the management personnel's mobile terminal; S6. Power equipment adopts joint detection technology that mainly uses transient ground voltage and ultrasonic detection and is supplemented by ultra-high frequency detection. By organically combining the three for joint detection, the efficiency and accuracy of detection can be improved in different scenarios, and the advantages can be complementary. It can collect on-site data in all directions, accurately grasp the status of equipment, and has a wider range of applications.

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