Switch cabinet partial discharge monitoring equipment

Abstract

The utility model discloses partial discharge monitoring equipment for a switch cabinet, and the equipment comprises an integrated intelligent partial discharge sensor and a data collector. The integrated intelligent partial discharge sensor comprises a processor, a USB interface, a charging management chip, a lithium ion battery, a synchronous positive and negative voltage DC-DC converter, a circuit power management unit, an ultrasonic unit, a TEV unit and a wireless communication module. Signals collected by the integrated intelligent partial discharge sensor are accessed to the multifunctional data gateway by the data collector through a wireless network via a network port / RS485 / serial port, and then the data are transmitted to a background terminal. According to the utility model, the problems of on-line monitoring of the partial discharge signal state of the switch cabinet, narrow actual measurement bandwidth of the TEV and easy interference of environmental electromagnetic waves in the TEV test are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of switch cabinets, in particular to a switch cabinet partial discharge monitoring device. Background Art

[0002] In the power system, switchgear is an important part of the power grid, and the stability of its operation directly affects the safety of the power grid. Switchgear relies on previous inspection, testing, and detection technologies, which often fail to meet the requirements of timely grasping equipment defects.

[0003] Traditional power outage preventive test technology mainly relies on withstand voltage test to check insulation performance. Since the time interval of the switchgear preventive test cycle is 3-6 years, it is difficult to find the insulation defects developed between the secondary preventive test intervals, which can easily cause insulation failure accidents. According to actual operating experience, there should be discharge phenomena before the failure occurs during the accident incubation period. Partial discharge is the main cause of insulation degradation and insulation failure of switchgear equipment. Its detection and evaluation have become an important means of insulation condition monitoring. Therefore, it is extremely significant to adopt appropriate partial discharge live test methods in the actual operation of switchgear. In the long-term operation of the switchgear, due to various objective reasons, the switchgear will have cable joint faults, busbar faults, contact faults, operating mechanism faults, lightning arrester faults, etc. during the installation and commissioning process, which brings hidden dangers to the reliable operation of the power grid and directly affects the safe and stable operation of the equipment.

[0004] Partial discharge failures caused by insulation failures account for 36% of the total failures of switchgear. The partial discharge detection equipment for medium and high voltage switchgear on the market today uses the transient ground voltage method. This technology has always had the problem of narrow measured bandwidth (narrow bandwidth will lead to inaccurate test data) and weak resistance to environmental electromagnetic waves. After more than 10 years of exploration, the industry has not yet perfectly solved this problem. At present, most switchgears still use manual operation and maintenance detection methods, basically using handheld partial discharge detection equipment to conduct an inspection once a quarter, which is not only time-consuming and labor-intensive, but also extremely expensive. Problems are often not discovered in a timely manner. (No long-term data accumulation to discover changes in partial discharge trend data).

[0005] Therefore, it is necessary to provide a switch cabinet partial discharge monitoring device to solve the above technical problems. The best way to monitor partial discharge is online monitoring, which can obtain the switch cabinet partial discharge trend data after a long period of data accumulation, so that problems can be found before the switch cabinet suffers a serious partial discharge accident through trend data analysis. Utility Model Content

[0006] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the title of the invention of this application to avoid blurring the purpose of this section, the abstract of the specification and the title of the invention, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] Therefore, the technology to be solved by the present invention is to accurately detect the switch cabinet through online monitoring, provide partial discharge trend data, and stably and accurately discover the changes in the degradation of the internal components of the switch cabinet equipment.

[0008] To solve the above technical problems, the utility model provides the following technical solutions: a switch cabinet partial discharge monitoring device, characterized in that the partial discharge monitoring device includes an integrated intelligent partial discharge sensor and a data collector, the integrated intelligent partial discharge sensor includes a processor, a USB interface, a charging management chip, a lithium-ion battery, a synchronous positive and negative voltage DC-DC converter, a circuit power management, an ultrasonic unit, a TEV unit and a wireless communication module, the USB interface, the charging management chip, the lithium-ion battery, the synchronous positive and negative voltage DC-DC converter and the circuit power management are electrically connected, the USB interface and the circuit power management are electrically connected to the processor, the ultrasonic unit and the TEV unit are electrically connected to the processor, the wireless communication module is electrically connected to the processor, the integrated intelligent partial discharge sensor detects the switch cabinet by ultrasonic measurement and transient ground wave measurement, the integrated intelligent partial discharge sensor is connected to the data collector, the signal collected by the integrated intelligent partial discharge sensor is connected to the multi-functional data gateway through the wireless network by the data collector through the network port / RS485 / serial port, and the data is transmitted to the background terminal.

[0009] As a preferred solution of the switch cabinet partial discharge monitoring device described in the utility model, the integrated intelligent partial discharge sensor also includes indicator light control, power on / off logic management and data storage area, and the indicator light control, the power on / off logic management and the data storage area are electrically connected to the processor.

[0010] As a preferred solution of the switch cabinet partial discharge monitoring device of the utility model, the shell shape of the integrated intelligent partial discharge sensor is an insulating rectangular parallelepiped with a protective function.

[0011] As a preferred solution of the switch cabinet partial discharge monitoring device of the utility model, the integrated intelligent partial discharge sensor is fixed on the cabinet surface by magnetic attraction and has an anti-slip function.

[0012] As a preferred solution of the switch cabinet partial discharge monitoring device of the utility model, the ultrasonic unit includes a signal amplifier, a signal conditioner and an ultrasonic probe.

[0013] As a preferred solution of the switch cabinet partial discharge monitoring device of the utility model, the TEV unit includes a signal amplification and detection, a signal conditioning and coupling board.

[0014] As a preferred solution of the switch cabinet partial discharge monitoring device described in the utility model, the amplitude range of the ultrasonic measurement is -9 to 65dBuV, and the frequency band range is 40 (+1 / -2)KHz; the amplitude range of the transient ground wave measurement is 0 to 60dBmV, and the frequency band range is 3 to 100MHZ, the measured + / -6db bandwidth is greater than or equal to 50MHZ, and the counting frequency range is 10Hz to 20Hz.

[0015] As a preferred solution of the switch cabinet partial discharge monitoring device described in the utility model, the data collector includes a processor, a POE power input terminal, a 12V DC voltage, a DC-DC converter, a power management module, an Ethernet chip, an RJ-45 network port, a wireless communication module, an RS-485 driver chip and an RS-232 interface chip. The POE power input terminal and the 12V DC voltage are connected to the DC-DC converter, the DC-DC converter is connected to the power management module and the processor, the power manager is connected to the Ethernet chip, the processor is connected to the Ethernet chip and the RJ-45 network port, the RS-485 driver chip is connected to the RS-232 interface chip, and the RS-485 driver chip is connected to the wireless communication module and the processor.

[0016] As a preferred solution of the switch cabinet partial discharge monitoring device described in the utility model, the communication interface of the data collector is: 1 Ethernet port, 1 RS-485 driver chip, 1 RS-232 interface chip, the downward communication mode is ZIGBEE, and the upward communication mode is RS485 / RJ45 / serial port.

[0017] The beneficial effects of the utility model are as follows: by magnetically attaching an integrated intelligent partial discharge sensor on the outer surface of the switch cabinet, the partial discharge data can be accurately tested through ultrasonic measurement and transient ground wave measurement, and the degradation changes of the internal components of the switch cabinet equipment can be stably and accurately discovered; the problem of narrow TEV measurement bandwidth and the problem that TEV testing is easily interfered by environmental electromagnetic waves are solved; in addition, it is an effective solution to the ultrasonic method, circuit noise and power supply ripple reduction, and by comparing the two monitoring methods of TEV and ultrasound, an effective monitoring method is provided for the safe operation of our power grid; at the same time, wavelet denoising technology, adaptive filtering technology and narrowband interference elimination technology are used to eliminate interference signals in the space and lines of the monitoring site, and statistical analysis can be performed on the amplitude, periodic pulse number, severity level, etc. of the discharge pulse, and multiple discharge fault points can be tracked. At the same time, an online continuous tracking and positioning mode of the discharge source is provided to track its displacement and intensity changes in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0019] Figure 1 A schematic diagram of the internal structure of an integrated intelligent partial discharge sensor of a switch cabinet partial discharge monitoring device according to an embodiment of the utility model;

[0020] Figure 2 A schematic diagram of the internal structure of a data collector of a switch cabinet partial discharge monitoring device according to an embodiment of the utility model;

[0021] Figure 3 An overall schematic diagram of a partial discharge sensor and a data collector of a switch cabinet partial discharge monitoring device according to an embodiment of the utility model. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general proportion, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0025] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0026] Example 1

[0027] Reference Figure 1-3The first embodiment of the utility model is a switch cabinet partial discharge monitoring device, characterized in that the partial discharge monitoring device includes an integrated intelligent partial discharge sensor and a data collector, the integrated intelligent partial discharge sensor includes a processor, a USB interface, a charging management chip, a lithium-ion battery, a synchronous positive and negative voltage DC-DC converter, a circuit power management, an ultrasonic unit, a TEV unit and a wireless communication module, the USB interface, the charging management chip, the lithium-ion battery, the synchronous positive and negative voltage DC-DC converter and the circuit power management are electrically connected, the USB interface and the circuit power management are electrically connected to the processor, the ultrasonic unit and the TEV unit are electrically connected to the processor, the wireless communication module is electrically connected to the processor, the integrated intelligent partial discharge sensor detects the switch cabinet by ultrasonic measurement and transient ground wave measurement, the integrated intelligent partial discharge sensor is connected to the data collector by signal, the signal collected by the integrated intelligent partial discharge sensor is connected to the multi-functional data gateway through the wireless network by the data collector through the network port / RS485 / serial port, and the data is transmitted to the background terminal. Specifically, the shell of the integrated intelligent partial discharge sensor is in the shape of a rectangular parallelepiped made of insulating material and having a protective function. The integrated intelligent partial discharge sensor also includes indicator light control, power on / off logic management and data storage area, and the indicator light control, the power on / off logic management and the data storage area are electrically connected to the processor. The integrated intelligent partial discharge sensor adopts a modular design and a unified data bus, so that data query and parameter setting can be performed on each unit without power outage; the protection level of the insulating protective cover of the integrated intelligent partial discharge sensor shell is IP65; the integrated intelligent partial discharge sensor is magnetically adsorbed on the surface of the switch cabinet, which is easy to deploy and ensures that the sensor surface is fully fitted with the surface of the cabinet to be tested; the integrated intelligent partial discharge sensor has an anti-slip function to prevent movement after installation; the integrated intelligent partial discharge sensor should be small in size and does not occupy the outer space of the electric cabinet after installation: the integrated intelligent partial discharge sensor adopts 2.4GHZ ZIGBEE / LORA 475MHZ (optional) wireless ad hoc network communication mode does not require wiring; the integrated intelligent partial discharge sensor is powered by lithium-ion batteries, and a single charge can ensure the use of more than 1 year (sampling interval is 1 hour once); the relevant data is stored in the data storage area; the integrated intelligent partial discharge sensor can use a variety of methods such as local or remote to set system parameters and upgrade software maintenance; the integrated intelligent partial discharge sensor can use acoustic and electrical joint testing (ultrasonic method and geoelectric wave method), and can effectively extract partial discharge signals through the combined analysis of acoustic and electrical data. It can display real-time waveforms, trend charts, frequency domain analysis charts and other graphics to provide data support for the effective analysis of discharge types and suspected fault points; the sampling frequency is configurable, and the sampling frequency can be automatically changed in abnormal situations to ensure the accuracy of the detection data.At the same time, the ultrasonic unit in the integrated intelligent partial discharge sensor includes a signal amplifier, a signal conditioner and an ultrasonic probe; the TEV unit includes signal amplification and detection, signal conditioning and a coupling plate. The ultrasonic probe can be used to detect the partial discharge sound wave signal. The coupling plate is a component of the intelligent partial discharge sensor for collecting transient ground waves. When the intelligent partial discharge sensor is reliably attached to the surface of the switch cabinet, it forms a capacitive coupling induction plate with the cabinet surface, effectively sensing the partial discharge signal on the surface of the switch cabinet. The data collector includes a processor, a POE power input terminal or a 12V DC voltage, a DC-DC power converter, a power management module, an Ethernet chip, an RJ-45 network port, a wireless communication module, an RS-485 driver chip and an RS-232 interface chip, wherein the POE power input terminal and the 12V DC voltage are connected to the DC-DC power converter, the DC-DC power converter is connected to the power management module and the processor, the power manager is connected to the Ethernet chip, the processor is connected to the Ethernet chip and the RJ-45 network port, the RS-485 driver chip is connected to the RS-232 interface chip, and the RS-485 driver chip is connected to the wireless communication module and the processor. The DC-DC power converter is connected to 5VDC.

[0028] The size of the integrated intelligent partial discharge sensor is 122mm*80mm*43mm, and the weight is about 0.43Kg; the size of the data collector is 120mm*105mm*28mm, and the weight is about 0.2Kg.

[0029] Transient Earth Wave Measurement

[0030] Amplitude range: 0~60dBmV

[0031] Frequency band: 3~100MHz

[0032] Resolution: 0.1dB

[0033] Accuracy: 0.1dB

[0034] Linearity error: ±10%

[0035] Measured + / -6db bandwidth >=50MHZ;

[0036] Counting frequency range: 10Hz~20kHz (ZIGBEE communication distance range in open area)>=150 meters;

[0037] LORA communication distance (open area)>=300 meters.

[0038] Ultrasonic measurement

[0039] Amplitude range: -9~65dBuV;

[0040] Frequency band range: 40 (+1 / -2) KHZ;

[0041] Resolution: 0.1dB;

[0042] Accuracy: 0.1dB Linearity error: ±10%.

[0043] Data Logger

[0044] 12DC input or POE power supply mode;

[0045] Power: ≤3W;

[0046] Downward communication method: ZIGBEE;

[0047] Upward communication mode: RS485 / RJ45 / serial port;

[0048] Upward communication protocol: ModBus / TCP;

[0049] GPS can complete system time correction and positioning functions;

[0050] Communication interface: 1 Ethernet port, 1 RS-485 driver chip, 1 RS-232 interface chip.

[0051] TEV transient ground wave

[0052] bandwidth

[0053] The measured bandwidth of TEV+ / -6db reaches more than 50MHZ, and the TEV amplitudes measured by signals at different frequency points within the bandwidth are basically the same, which has been a problem that has troubled the industry for many years. The national standard requires 10MHZ (many manufacturers do not exceed 6MHZ, and some even only 2-3MHZ). This is also the reason why the industry believes that the measurement results of TEV can only be used as a reference.

[0054] Interference immunity

[0055] The unique signal chain processing technology solves the problem that TEV is easily interfered by external signals and ensures the consistency and repeatability of test results under specific signal sources.

[0056] Power supply noise

[0057] Unique and sophisticated power supply processing technology, the system power supply ripple does not exceed 8mV VPP, ensuring the accuracy and stability of the sampling data.

[0058] AA Air Ultrasound

[0059] The unique power supply noise elimination technology ensures the stable acquisition of small signals of -9db uv, and the sophisticated signal chain conditioning technology and algorithm ensure the accuracy and consistency of each sampling of specific small signals (uV level);

[0060] Ultrasonic and transient ground voltage signal detection can be configured according to user requirements. Various partial discharge signals are collected through the intelligent data collector host, and then the operating status of distribution equipment (such as switch cabinets, ring network cabinets, etc.) is monitored through edge computing;

[0061] Wavelet noise elimination technology, adaptive filtering technology, and narrowband interference elimination technology are used to eliminate interference signals in the space and lines at the monitoring site. At the same time, statistical analysis can be performed on the amplitude, periodicity, pulse number, severity level, etc. of the discharge pulse, and multiple discharge fault points can be tracked. At the same time, an online continuous tracking and positioning mode for the discharge source is provided to track its displacement and intensity changes in real time.

[0062] Application Environment

[0063] Relative humidity: 5% to 95% without condensation;

[0064] Working temperature: -25℃~70℃;

[0065] Storage temperature: -40℃~84℃》;

[0066] power supply

[0067] Working power supply: 3.7V lithium-ion built-in battery;

[0068] Charger: 5V / 2A dedicated power adapter;

[0069] Charging interface: type C;

[0070] Battery life: single battery > 1 year (monitoring once per hour);

[0071] Working indicator light

[0072] Power on: The red and blue indicator lights are on for 3 seconds at the same time;

[0073] Router connection is normal: blue light flashes for 3s;

[0074] The router connection is abnormal: the red light flashes for 1s;

[0075] Low battery: the red light flashes at intervals of 1s2;

[0076] Power on and working status indication

[0077] Power button: short press to turn on, short press to turn off (after turning on, when the blue indicator light flashes alternately, short press the power button once to turn off);

[0078] Charging indicator

[0079] Red: Charging; Green: Charging completed;

[0080] The red and green lights flash alternately: charging failure;

[0081] Alarm threshold setting and indication function (green, orange and red); sensor array operation status detection (self-diagnosis); amplitude measurement statistics; pulse counting statistics,

[0082] PD severity calculation; PD spectrum analysis:

[0083] Manual monitoring in manual mode (when an early warning is found, the background can be switched to manual monitoring in manual mode);

[0084] In summary, by installing integrated intelligent partial discharge sensors and data collectors in the switch cabinet, online partial discharge monitoring of the switch cabinet can be carried out. The integrated intelligent partial discharge sensors and data collectors can work intelligently, with a sampling interval of once an hour, and will transmit the collected data to the background terminal. Relevant staff can understand the status of the switch cabinet in real time based on the transmitted data. There is no need for manual timed detection, which saves labor costs and greatly improves work efficiency. The equipment is small, stable, and highly accurate, making it suitable for promotion.

[0085] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In order to provide a concise description of the exemplary embodiments, all features of the actual embodiments may not be described (i.e., those features that are not related to the best mode currently considered to perform the present invention, or those features that are not related to the implementation of the present invention).

[0086] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0087] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A switch cabinet partial discharge monitoring device, characterized in that: The partial discharge monitoring device includes an integrated intelligent partial discharge sensor and a data collector. The integrated intelligent partial discharge sensor includes a processor, a USB interface, a charging management chip, a lithium-ion battery, a synchronous positive and negative voltage DC-DC converter, a circuit power management, an ultrasonic unit, a TEV unit and a wireless communication module. The USB interface, the charging management chip, the lithium-ion battery, the synchronous positive and negative voltage DC-DC converter and the circuit power management are electrically connected. The USB interface and the circuit power management are electrically connected to the processor. The ultrasonic unit and the TEV unit are electrically connected to the processor. The wireless communication module is electrically connected to the processor. The integrated intelligent partial discharge sensor detects the switch cabinet by ultrasonic measurement and transient ground wave measurement. The integrated intelligent partial discharge sensor is connected to the data collector. The signal collected by the integrated intelligent partial discharge sensor is connected to the multi-functional data gateway through the wireless network by the data collector through the network port / RS485 / serial port, and the data is transmitted to the background terminal.

2. The switch cabinet partial discharge monitoring device according to claim 1, characterized in that: The integrated intelligent partial discharge sensor also includes an indicator light control, a power on / off logic management and a data storage area, and the indicator light control, the power on / off logic management and the data storage area are electrically connected to the processor.

3. The switch cabinet partial discharge monitoring device according to claim 2, characterized in that: The shell of the integrated intelligent partial discharge sensor is in the shape of an insulating rectangular parallelepiped with a protective function.

4. The switch cabinet partial discharge monitoring device according to claim 3 is characterized in that: The integrated intelligent partial discharge sensor is adsorbed on the cabinet surface by magnetic attraction and has an anti-slip function.

5. The switch cabinet partial discharge monitoring device according to claim 1, characterized in that: The ultrasonic unit includes a signal amplifier, a signal conditioner and an ultrasonic probe.

6. The switch cabinet partial discharge monitoring device according to claim 5, characterized in that: The TEV unit includes a signal amplification and detection, a signal conditioning and a coupling board.

7. The switch cabinet partial discharge monitoring device according to claim 1, characterized in that: The amplitude range of the ultrasonic measurement is -9 to 65dBuV, and the frequency range is 40 (+1 / -2)KHz; the amplitude range of the transient ground wave measurement is 0 to 60dBmV, and the frequency range is 3 to 100MHZ. The measured + / -6db bandwidth is >= 50MHZ, and the counting frequency range is 10Hz to 20KHz.

8. The switch cabinet partial discharge monitoring device according to claim 1, characterized in that: The data acquisition device includes a processor, a POE power input terminal, a DC-DC power converter, a power management module, an Ethernet chip, an RJ-45 network port, a wireless communication module, an RS-485 driver chip and an RS-232 interface chip. The POE power input terminal is connected to the DC-DC converter, the DC-DC power converter is connected to the power management module and the processor, the power management module is connected to the Ethernet chip, the processor is connected to the Ethernet chip and the RJ-45 network port, the RS-485 driver chip is connected to the RS-232 interface chip, and the RS-485 driver chip is connected to the wireless communication module and the processor.

9. The switch cabinet partial discharge monitoring device according to claim 8, characterized in that: The communication interface of the data collector is: 1 Ethernet port, 1 RS-485 driver chip, 1 RS-232 interface chip, the downward communication mode is ZIGBEE, and the upward communication mode is RS485 / RJ45 / serial port.

Images