An intelligent online monitoring system and device for partial discharge of switch cabinet

Abstract

The present invention discloses an intelligent online monitoring system and device for partial discharge of a switch cabinet, belonging to the field of switch cabinet monitoring. The system includes an online real-time monitoring module, a real-time data processing module, a real-time data acquisition module, a real-time data sending module, a real-time data monitoring module and a data retrieval interface module; the online real-time monitoring module is used to monitor the ultrasonic wave and electromagnetic wave information generated by the partial discharge inside the switch cabinet in real time through the partial discharge sensor, and monitor the temperature at the contact point in the switch cabinet in real time through the wireless temperature sensor. After determining that partial discharge occurs in the switch cabinet, the specific point where the partial discharge occurs in the switch cabinet can be accurately located according to the time difference between the electromagnetic pen and the ultrasonic wave and the attenuation of the electromagnetic wave energy, and the information is fed back to the management personnel, so that the management personnel can accurately and quickly locate the point where the partial discharge occurs in the switch cabinet.

Description

Technical Field

[0001] The invention relates to switch cabinet monitoring, and in particular to an intelligent online monitoring system and device for partial discharge of a switch cabinet. Background Art

[0002] Partial discharge is a pulse discharge that will produce a series of physical phenomena and chemical changes such as light, sound, electrical and mechanical vibrations inside and around the power equipment. Partial discharge is a poor insulation phenomenon in the switch cabinet, which can easily lead to circuit faults such as short circuits in the switch cabinet, and even fire in the switch cabinet. Therefore, monitoring partial discharge in the switch cabinet is one of the routine and important tasks of power inspection. At present, manual inspection is used to determine whether partial discharge occurs in the switch cabinet, or by installing monitoring equipment in the room where the switch cabinet is placed, and judging whether partial discharge occurs in the switch cabinet through real-time monitoring images. Whether it is manual inspection or monitoring through monitoring equipment, it relies heavily on manual labor and requires manual judgment, which is prone to untimely discovery or misjudgment, and it is impossible to accurately and quickly locate the point where partial discharge occurs. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to provide an intelligent online monitoring system for partial discharge of a switch cabinet; another purpose of the present invention is to provide an intelligent online monitoring device for partial discharge of a switch cabinet.

[0004] Technical solution: An intelligent online monitoring system for partial discharge of a switch cabinet, the system comprises an online real-time monitoring module, a real-time data processing module, a real-time data acquisition module, a real-time data transmission module, a real-time data monitoring module and a data retrieval interface module;

[0005] Online real-time monitoring module: used to monitor the ultrasonic and electromagnetic wave information generated by partial discharge inside the switch cabinet in real time through the partial discharge sensor, and to monitor the temperature at the contact point inside the switch cabinet in real time through the wireless temperature sensor;

[0006] Real-time data processing module: used to process the ultrasonic and electromagnetic wave information data monitored by the partial discharge sensor. When the ultrasonic and electromagnetic wave information data exceed the preset threshold parameters, it is judged that partial discharge occurs inside the switch cabinet. At the same time, the specific point where partial discharge occurs in the switch cabinet can be determined according to the energy attenuation of the electromagnetic wave.

[0007] Real-time data acquisition module: used to collect information data monitored by the online real-time monitoring module and information data obtained after processing and analysis by the real-time data processing module;

[0008] Real-time data sending module: used to send the information data collected by the real-time data collection module to the real-time data monitoring module;

[0009] Data real-time monitoring module: used to receive information data sent by the data real-time sending module, store it, and display it.

[0010] Preferably, the partial discharge sensor comprises an ultrasonic partial discharge sensor and an ultra-high frequency partial discharge sensor; the ultrasonic partial discharge sensor and the ultra-high frequency partial discharge sensor are respectively used to monitor ultrasonic and electromagnetic wave information data generated after partial discharge occurs.

[0011] Preferably, the wireless temperature sensor includes a battery-powered strap-type temperature sensor and an electricity-drawing strap-type temperature sensor; the battery-powered strap-type temperature sensor and the electricity-drawing strap-type temperature sensor are used to be installed and fixed at the contacts in the switch cabinet, so as to monitor the temperature at the contacts in the switch cabinet in real time. According to the specific conditions of the contacts in the switch cabinet, the battery-powered strap-type temperature sensor or the electricity-drawing strap-type temperature sensor is installed and fixed.

[0012] Preferably, the real-time data processing module includes a data temporary storage module, a data analysis module and a result feedback module;

[0013] Data temporary storage module: used to temporarily store the ultrasonic and electromagnetic wave information data monitored by the partial discharge sensor;

[0014] Data analysis module: used to process and analyze the information data temporarily stored in the data storage module. When the ultrasonic and electromagnetic wave information data exceeds the preset threshold parameters, it can be judged that partial discharge occurs in the switch cabinet and the specific point where the partial discharge fault occurs can be determined;

[0015] Result feedback module: used to feed back the partial discharge judgment results and specific point information of partial discharge obtained by the data analysis module to the real-time data acquisition module.

[0016] Preferably, after the data analysis module determines that partial discharge occurs in the switch cabinet, the distance between the partial discharge point and the ultrasonic partial discharge sensor and the ultra-high frequency sensor is determined based on the time difference from the ultrasonic partial discharge sensor from no detection to the ultrasonic frequency exceeding the threshold parameter and the time difference from the ultra-high frequency partial discharge sensor from no detection to the electromagnetic wave frequency exceeding the threshold parameter:

[0017]

[0018] Among them, r1 and r2 are the distances between the PD point and the UHF PD sensor and the ultrasonic PD sensor, respectively; c is the propagation speed of electromagnetic waves in the air; v is the propagation speed of ultrasonic waves in the air; Δt1 and Δt2 are the time difference from no detection to the electromagnetic wave frequency exceeding the threshold parameter by the UHF PD sensor and the time difference from no detection to the ultrasonic wave frequency exceeding the threshold parameter by the ultrasonic PD sensor, respectively;

[0019] At this time, the partial discharge point is any point on the circle with radius r1, and the partial discharge point is any point on the circle with radius r2. The two circles intersect, so two intersection points can be obtained. Then, any corner point at the bottom of the switch cabinet is used as the origin and 0.1m is used as the unit interval of the coordinate axis to obtain the coordinates of the two intersection points. Remove the intersection points that meet the following conditions:

[0020] x≤0 or x≥L or z≤0 or z≥H

[0021] Among them, x and z are the coordinate values ​​of the intersection on the x-axis and z-axis respectively, L is the length of the switch cabinet, and H is the height of the switch cabinet. Finally, the point where partial discharge occurs can be obtained.

[0022] Preferably, after the data analysis module obtains the point where the partial discharge occurs, since the switch cabinet is a three-dimensional structure, the point obtained is the projection point where the partial discharge occurs. At this time, according to the frequency of the electromagnetic wave monitored by the UHF partial discharge sensor, the electromagnetic wave energy generated by the point where the partial discharge occurs can be obtained as follows:

[0023] E=(3·U·I) / 16·π 2 ·R 5 ·C

[0024] Among them, E is the electromagnetic wave energy generated by the point where partial discharge occurs, U is the voltage at the point where partial discharge occurs, I is the current passing through the point where partial discharge occurs, R is the radius of the sphere centered at the point where partial discharge occurs, R = 1-2 cm, and C is the speed of light; then combined with the electromagnetic wave energy monitored by the UHF partial discharge sensor, the distance from the specific point on the straight line where the projection point where partial discharge occurs is located to the UHF partial discharge sensor can be obtained as:

[0025]

[0026] Where d is the distance from the point where partial discharge occurs to the UHF partial discharge sensor, ɑ is the attenuation coefficient of the electromagnetic wave, and E d It is the electromagnetic wave energy monitored by the UHF partial discharge sensor; then according to:

[0027]

[0028] The distance d between the specific point on the straight line where the projection point of the partial discharge occurs and the projection point where the partial discharge occurs can be obtained. t , Z A It is the vertical distance from the projection point where the partial discharge occurs to the UHF partial discharge sensor; ultimately the specific point where the partial discharge occurs can be obtained.

[0029] Preferably, the data real-time monitoring module includes a data receiving module, a data storage module and a data display module;

[0030] Data receiving module: used to receive information data sent by the real-time data sending module;

[0031] Data storage module: used to store the information data received by the data receiving module;

[0032] Data display module: used to retrieve the information data to be displayed from the data storage module and display the information data in a specific format.

[0033] Preferably, the system also includes a data retrieval interface module, which is used to enable a third-party system to establish a link with the data real-time monitoring module through the module when authorized, thereby facilitating the authorized third-party system to retrieve information data from the data real-time monitoring module.

[0034] An intelligent online monitoring device for partial discharge of a switch cabinet comprises a built-in ultrasonic partial discharge sensor, an ultra-high frequency partial discharge sensor, an industrial-grade microprocessor and a communication module. After the ultrasonic partial discharge sensor and the ultra-high frequency partial discharge sensor monitor information data, the industrial-grade microprocessor processes and analyzes the information data to determine whether partial discharge occurs in the switch cabinet, and gives the specific location of the partial discharge. The monitored information data and the processed information data are uploaded through the communication module.

[0035] Preferably, the communication module is an RS485 communication module.

[0036] Beneficial effects:

[0037] (1) Through the joint monitoring of ultrasonic partial discharge sensors and ultra-high frequency partial discharge sensors, the ultrasonic information and electromagnetic wave information in the switch cabinet can be monitored in real time, and the monitored ultrasonic information and electromagnetic wave information can be compared with the preset threshold parameters. When the ultrasonic information and electromagnetic wave information exceed the preset threshold parameters, it is judged that partial discharge occurs in the switch cabinet, so that the management personnel can be warned in time, so that the management personnel can know the partial discharge in the switch cabinet in time.

[0038] (2) After determining that partial discharge has occurred in the switch cabinet, the specific point where the partial discharge has occurred in the switch cabinet can be accurately located based on the time difference between the reception of the electromagnetic pen and the ultrasonic wave and the attenuation of the electromagnetic wave energy. The information can be fed back to the management personnel, so that the management personnel can accurately and quickly locate the point where the partial discharge has occurred in the switch cabinet, thereby avoiding unnecessary waste of time caused by manual inspections, thereby delaying the progress of switch cabinet maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the principle of the system of the present invention;

[0040] Figure 2 is a schematic diagram of locating a partial discharge projection point according to the present invention;

[0041] Figure 3 A schematic diagram of locating specific points of partial discharge according to the present invention;

[0042] Figure 4 This is the installation diagram of the partial discharge monitoring device for the switch cabinet. DETAILED DESCRIPTION

[0043] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Example

[0045] like Figure 1 As shown, an intelligent online monitoring system for partial discharge of a switch cabinet is composed of a partial discharge monitoring device for a switch cabinet, a wireless temperature sensor (including a battery-powered strap temperature sensor and an electricity-drawing strap temperature sensor), a comprehensive detection device, and a monitoring terminal. The wireless temperature sensor sends the monitored information to the comprehensive detection device via wireless communication (for example, wireless communication methods such as WIFI, 4G\5G, etc.). The partial discharge monitoring device for the switch cabinet communicates with the comprehensive detection device via an RS485 communication module. The partial discharge monitoring device for the switch cabinet is installed on the switch cabinet, such as Figure 4 As shown. According to the actual situation of the contacts in the switch cabinet, a battery-powered strap temperature sensor or an electric meter strap temperature sensor is installed on each contact. At the same time, a comprehensive detection device is installed on the switch cabinet.

[0046] The switch cabinet partial discharge monitoring device includes a partial discharge sensor composed of an ultrasonic partial discharge sensor and an ultra-high frequency partial discharge sensor, an online real-time monitoring module, and a real-time data processing module composed of a data temporary storage module, a data analysis module, and a result feedback module. The comprehensive detection device is composed of a real-time data acquisition module and a real-time data transmission module. The monitoring terminal includes a real-time data monitoring module and a data retrieval interface module composed of a data receiving module, a data storage module, and a data display module.

[0047] In the process of monitoring partial discharge of the switch cabinet, the ultrasonic partial discharge sensor and the ultra-high frequency partial discharge sensor monitor the ultrasonic frequency and electromagnetic wave frequency information inside the switch cabinet in real time, and forward the monitored ultrasonic frequency and electromagnetic wave frequency information to the data temporary storage module in the real-time data processing module in real time for temporary storage. Then, the data analysis module compares the monitored ultrasonic frequency and electromagnetic wave frequency information with the preset threshold parameters. If the ultrasonic frequency and electromagnetic wave frequency information exceed the preset threshold parameters, it is determined that partial discharge occurs inside the switch cabinet. Then, the distance r2 and r1 of the partial discharge point from the ultrasonic partial discharge sensor to the ultrasonic frequency exceeding the threshold parameter is determined based on the time difference Δt2 from the ultrasonic partial discharge sensor to the time difference Δt1 from the ultra-high frequency partial discharge sensor to the time difference Δt1 from the ultra-high frequency partial discharge sensor to the electromagnetic wave frequency exceeding the threshold parameter:

[0048]

[0049] Among them, c is the propagation speed of electromagnetic waves in the air, and v is the propagation speed of ultrasonic waves in the air.

[0050] At this time, the local discharge point is any point on the circle with radius r1, and the local discharge point is any point on the circle with radius r2. The two circles intersect, so that two intersection points (A, B) can be obtained. Then, any corner point at the bottom of the switch cabinet is taken as the origin and 0.1m is taken as the unit interval of the coordinate axis, so that the coordinates of the two intersection points can be obtained, such as Figure 2 And remove the intersection points that meet the following conditions:

[0051] x≤0 or x≥L or z≤0 or z≥H

[0052] Among them, x and z are the coordinate values ​​of the intersection on the x-axis and z-axis respectively, L is the length of the switch cabinet, and H is the height of the switch cabinet. Thus, the point where the partial discharge occurs can be obtained. Since the switch cabinet is a three-dimensional structure, the point obtained is the projection point where the partial discharge occurs, and the specific point where the partial discharge occurs should be on the straight line C where the projection point is located, such as Figure 3At this time, according to the frequency of the electromagnetic wave monitored by the UHF partial discharge sensor, the electromagnetic wave energy E generated at the point where the partial discharge occurs can be obtained as:

[0053] E=(3·U·I) / 16·π 2 ·R 5 ·C

[0054] Among them, U is the voltage at the point where partial discharge occurs, I is the current passing through the point where partial discharge occurs, and R is the radius of the sphere centered on the point where partial discharge occurs, R = 1cm. At this time, since the radius of the sphere centered on the point where partial discharge occurs is small, the attenuation of the electromagnetic wave is extremely small, and the attenuation of the electromagnetic wave energy is negligible. Therefore, the electromagnetic wave energy at the spherical surface with a radius of R is used as the electromagnetic wave energy generated by the point where partial discharge occurs. C is the speed of light; then combined with the electromagnetic wave energy monitored by the UHF partial discharge sensor, the distance d from the specific point where partial discharge occurs to the UHF partial discharge sensor can be obtained as:

[0055]

[0056] Among them, ɑ is the attenuation coefficient of electromagnetic waves. Since the switch cabinet has strict humidity and temperature requirements, this coefficient is obtained by averaging the attenuation coefficient results of electromagnetic waves obtained through multiple experiments (for example, alternative measurement experiment method, tomography experiment method, etc.) under strictly controlled humidity and temperature. d It is the electromagnetic wave energy monitored by the UHF partial discharge sensor; then according to:

[0057]

[0058] The distance d between the specific point on the straight line where the projection point of the partial discharge occurs and the projection point where the partial discharge occurs can be obtained. t , Z A is the vertical distance from the projection point where the partial discharge occurs to the UHF partial discharge sensor; finally, the specific point Q where the partial discharge occurs can be obtained according to the established coordinate system, such as Figure 3 Then, the specific point information of the local release is fed back to the real-time data acquisition module through the result feedback module.

[0059] After the real-time data acquisition module completes the collection of information about the ultrasonic partial discharge sensor, the ultra-high frequency partial discharge sensor, the wireless temperature measurement sensor, and the specific location where the partial discharge occurs, it sends the information to the real-time data monitoring module through the real-time data sending module. After the real-time data monitoring module receives the information data through the data receiving module, it stores the information data in the data storage module. At the same time, the data display module retrieves the data from the data storage module and displays the data in the specified display format and style, so that the management personnel can clearly and detailedly grasp the situation inside the switch cabinet.

[0060] In addition, the third-party authorization system can also establish a link with the data real-time monitoring module through the data retrieval interface module, so that the authorized third-party system can retrieve information data from the data real-time monitoring module for use.

[0061] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An intelligent online monitoring system for partial discharge of switch cabinet, characterized in that: The system includes an online real-time monitoring module, a real-time data processing module, a real-time data acquisition module, a real-time data sending module, a real-time data monitoring module and a data retrieval interface module; Online real-time monitoring module: used to monitor the ultrasonic and electromagnetic wave information generated by partial discharge inside the switch cabinet in real time through the partial discharge sensor, and to monitor the temperature at the contact point inside the switch cabinet in real time through the wireless temperature sensor; Real-time data processing module: used to process the ultrasonic and electromagnetic wave information data monitored by the partial discharge sensor. When the ultrasonic and electromagnetic wave information data exceed the preset threshold parameters, it is judged that partial discharge occurs inside the switch cabinet, and the specific point where the partial discharge occurs in the switch cabinet can be determined according to the energy attenuation of the electromagnetic wave. The module includes a data temporary storage module, a data analysis module and a result feedback module. The data temporary storage module: used to temporarily store the ultrasonic and electromagnetic wave information data monitored by the partial discharge sensor; the data analysis module: used to process and analyze the information data temporarily stored in the data temporary storage module. When the ultrasonic and electromagnetic wave information data exceed the preset threshold parameters, the module generates a signal. After the number is obtained, the partial discharge in the switch cabinet is judged, and the specific point where the partial discharge fault occurs is determined; the result feedback module is used to feed back the partial discharge judgment result obtained by the data analysis module and the specific point information of the partial discharge to the real-time data acquisition module; wherein the specific process of the data analysis module determining the specific point where the partial discharge fault occurs is: after judging the partial discharge in the switch cabinet, the distance of the partial discharge point from the ultrasonic partial discharge sensor to the ultrasonic partial discharge sensor and the ultra-high frequency sensor is determined according to the time difference from the ultrasonic partial discharge sensor from no to the ultrasonic frequency exceeding the threshold parameter and the time difference from the ultra-high frequency partial discharge sensor from no to the electromagnetic wave frequency exceeding the threshold parameter: ； in, r 1 , r 2 are the distances from the PD point to the UHF PD sensor and to the ultrasonic PD sensor, respectively. c is the propagation speed of electromagnetic waves in air, v is the propagation speed of ultrasound in air, Δt 1 , Δt 2 They are respectively the time difference from no detection to the electromagnetic wave frequency exceeding the threshold parameter of the UHF PD sensor and the time difference from no detection to the ultrasonic wave frequency exceeding the threshold parameter of the ultrasonic PD sensor; At this time, the local discharge point is r 1 Any point on the circle with radius r 2 The two circles intersect at any point on the circumference of the radius, so that two intersection points can be obtained. Then, any corner point at the bottom of the switch cabinet is taken as the origin and 0.1m is taken as the unit interval of the coordinate axis, so that the coordinates of the two intersection points can be obtained. The intersection points that meet the following conditions are removed: ； in, x , z are the coordinates of the intersection point on the x-axis and z-axis respectively, L is the length of the switch cabinet, H is the height of the switch cabinet, and finally the point where partial discharge occurs can be obtained; Since the switch cabinet is a three-dimensional structure, the point obtained is the projection point where the partial discharge occurs. At this time, according to the frequency of the electromagnetic wave monitored by the UHF partial discharge sensor, the electromagnetic wave energy generated by the point where the partial discharge occurs can be obtained as: ； Among them, E is the electromagnetic wave energy generated by the point where partial discharge occurs, U is the voltage at the point where partial discharge occurs, I is the current passing through the point where partial discharge occurs, R is the radius of the sphere centered at the point where partial discharge occurs, R=1cm, and C is the speed of light; then combined with the electromagnetic wave energy monitored by the UHF partial discharge sensor, the distance from the specific point on the straight line where the projection point where partial discharge occurs is located to the UHF partial discharge sensor can be obtained as: ； in, d is the distance from the point where partial discharge occurs to the UHF partial discharge sensor. ɑ is the attenuation coefficient of electromagnetic waves, E d It is the electromagnetic wave energy monitored by the UHF partial discharge sensor; then according to: ； The distance between the specific point on the straight line where the projection point of the partial discharge occurs and the projection point where the partial discharge occurs can be obtained. d t , Z A It is the vertical distance from the projection point where the partial discharge occurs to the UHF partial discharge sensor; finally, the specific point where the partial discharge occurs can be obtained; Real-time data acquisition module: used to collect information data monitored by the online real-time monitoring module and information data obtained after processing and analysis by the real-time data processing module; Real-time data sending module: used to send the information data collected by the real-time data collection module to the real-time data monitoring module; Data real-time monitoring module: used to receive information data sent by the data real-time sending module, store it, and display it.

2. The intelligent online monitoring system for partial discharge of switch cabinet according to claim 1 is characterized in that: The partial discharge sensor comprises an ultrasonic partial discharge sensor and an ultra-high frequency partial discharge sensor; the ultrasonic partial discharge sensor and the ultra-high frequency partial discharge sensor are respectively used to monitor ultrasonic and electromagnetic wave information data generated after partial discharge occurs.

3. The intelligent online monitoring system for partial discharge of switch cabinet according to claim 1 is characterized in that: The wireless temperature sensor includes a battery-powered strap-type temperature sensor and an electricity-drawing strap-type temperature sensor; the battery-powered strap-type temperature sensor and the electricity-drawing strap-type temperature sensor are used to be installed and fixed at the contacts in the switch cabinet, so as to monitor the temperature at the contacts in the switch cabinet in real time. According to the specific conditions of the contacts in the switch cabinet, the battery-powered strap-type temperature sensor or the electricity-drawing strap-type temperature sensor is installed and fixed.

4. The intelligent online monitoring system for partial discharge of switch cabinet according to claim 1 is characterized in that: The data real-time monitoring module includes a data receiving module, a data storage module and a data display module; Data receiving module: used to receive information data sent by the real-time data sending module; Data storage module: used to store the information data received by the data receiving module; Data display module: used to retrieve the information data to be displayed from the data storage module and display the information data in a specific format.

5. The intelligent online monitoring system for partial discharge of switch cabinet according to claim 1 is characterized in that: The system also includes a data retrieval interface module, which is used to enable a third-party system to establish a link with the data real-time monitoring module through the module when authorized, so that the authorized third-party system can retrieve information data from the data real-time monitoring module.

6. A device using the intelligent online monitoring system for partial discharge of a switch cabinet according to any one of claims 1 to 5, characterized in that: The device includes built-in ultrasonic partial discharge sensors, ultra-high frequency partial discharge sensors, industrial-grade microprocessors and communication modules. After the ultrasonic partial discharge sensors and ultra-high frequency partial discharge sensors monitor the information data, they are processed and analyzed by the industrial-grade microprocessor to determine whether partial discharge occurs in the switch cabinet, and the specific location of the partial discharge is given. The monitored information data and the processed information data are uploaded through the communication module.

7. The intelligent online monitoring device for partial discharge of switch cabinet according to claim 6 is characterized in that: The communication module is an RS485 communication module.

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