Multi-mode sensing high-voltage switch cabinet insulation fault diagnosis device
By using a multimodal sensing high-voltage switchgear insulation fault diagnosis device, combined with ultrasonic and pulse current detection, a multi-dimensional feature analysis system is constructed, which solves the sensitivity and anti-interference problems in high-voltage switchgear insulation fault detection and achieves high-precision fault diagnosis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-07
- Publication Date
- 2026-03-27
AI Technical Summary
Existing high-voltage switchgear insulation fault detection technologies suffer from limited sensitivity, insufficient immunity to interference, and low reliability of single-source detection, making it difficult to meet the technical requirements for comprehensive evaluation.
A multimodal sensing high-voltage switchgear insulation fault diagnosis device is adopted, which combines ultrasonic detection and pulse current detection to construct a time-frequency-space multidimensional feature analysis system. The system uses piezoelectric ultrasonic sensors and ceramic insulator capacitors for signal capture and processing to achieve multi-source data fusion.
It significantly improves the accuracy of discharge mode recognition and fault location, and enhances the robustness of detection in complex electromagnetic environments.
Smart Images
Figure CN224052345U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to high -voltage switchgear partial discharge detection technical field, concretely relates to a kind of multimodal perception high-voltage switchgear insulation fault diagnosis device. BACKGROUND
[0002] As the core node equipment of power distribution network, high-voltage switchgear bears the key functions of electric energy receiving, distribution and control in 35kV and below voltage level systems. The 2022 operation report of State Grid pointed out that the number of 10kV level switchgears in operation in China has exceeded 6 million, with an annual growth rate of 8.7%, and its operation stability directly affects the urban power supply reliability index and the terminal user power quality. In the special field of rail transit, data center and other power supply continuity requirements, the insulation performance of equipment becomes the core parameter to determine the safe operation of power supply system.
[0003] There are potential risks of inducing insulation defects in each link of the equipment life cycle: micro air gap (typical size 0.1-3mm) and residual metal particles (particle size 50-500μm) caused by process defects in the manufacturing link; epoxy resin microcracks (annual expansion 0.02mm) caused by mechanical stress in the transportation and installation process; typical defect modes such as contact resistance deterioration (resistance increase by 15% for thousands of operations) caused by thermal cycle effect in the operation stage, and tracking on the surface of insulation materials (corona onset field strength decreases to 1.2kV / mm) in humid environment. These micro-defects can cause the local electric field intensity distortion coefficient to reach 2.3-5.6 times, and trigger more than 78% of the discharge initiation probability.
[0004] The evolution process of partial discharge presents significant nonlinear characteristics: in the initial stage, the discharge quantity is mainly distributed in the range of 5-50pC, and the discharge frequency is less than 10 times / min; in the development stage, the amplitude can jump to 200-800pC, and the signal strength in the characteristic frequency band (300kHz-1.5MHz) is improved by 20dB; in the final stage, pre-breakdown pulses with single discharge quantity exceeding 2000pC appear. It is worth noting that under the action of discharge heat effect (pyrolysis threshold about 180℃), the dielectric loss factor tanδ of organic insulation materials increases at a rate of 0.05% / year, eventually leading to a 35%-60% decrease in power frequency withstand voltage strength, and the incubation period of forming through breakdown is usually 3-8 years.
[0005] As an important inducement of insulation deterioration, partial discharge parameters also constitute the core indicators for evaluating insulation status. By accurately detecting discharge signals, potential defects of equipment can be effectively identified, real-time monitoring, fault diagnosis and life assessment of insulation status can be realized, data support can be provided for preventive maintenance, and the safety of power grid operation can be significantly improved.
[0006] In the existing live detection technology, the ultrasonic wave method and the pulse current method are most widely used. The pulse current method is based on detecting impedance to capture the discharge pulse current, has 0.1 pC level sensitivity and quantitative detection advantages, but is easily affected by wide frequency interference sources such as frequency conversion devices; the ultrasonic wave method captures the discharge ultrasonic signal through the shell sensor, has the anti-electromagnetic interference characteristic, but the sound wave attenuation of the internal defect of the epoxy pouring body is up to 30 dB / cm, and the detection rate of the deep defect is less than 40%.
[0007] The existing single detection method has inherent limitations in sensitivity, anti-interference and the like, and is difficult to meet the technical requirements of comprehensive evaluation of the insulation state of the high-voltage switch cabinet. Practical new type content
[0008] The utility model discloses a kind of multi-modal perception high-voltage switch cabinet insulation fault diagnosis devices, to solve the sensitivity limitation, anti-interference deficiency and single-source detection low reliability of existing high-voltage switch cabinet insulation fault detection exist Technical problems.
[0009] To achieve the above-mentioned purpose, the utility model adopts the following technical solutions:
[0010] A kind of multi-modal perception high-voltage switch cabinet insulation fault diagnosis device, including partial discharge signal detection module, signal conditioning module, data processing module, edge computing gateway and PC host computer;The partial discharge signal detection module includes ultrasonic detection sensor and pulse current detection sensor, and is connected with signal conditioning module respectively by radio frequency signal line;The signal conditioning module is connected with data processing module by radio frequency coaxial line;The data processing module and edge computing gateway carry out data transmission by LoRa communication network;The edge computing gateway and PC host computer carry out data transmission by 4G or 5G network.
[0011] The utility model constructs time-frequency space multidimensional feature analysis system through pulse current and ultrasonic wave double mode sensing coordination mechanism: the former exerts 0.1 pC level high sensitivity characteristic of pulse current method, accurately quantifies medium internal electric tree branch discharge and along surface discharge parameter;The latter utilizes the strong anti-interference advantage of ultrasonic detection, realizes effective signal capture in complex electromagnetic environment, and after double mode data is fused by feature level, discharge mode recognition accuracy and fault positioning accuracy are significantly improved.
[0012] The utility model further illustrates that the ultrasonic detection sensor adopts piezoelectric ultrasonic sensor, and is attached and installed on the cabinet body of high-voltage switch cabinet.
[0013] The ultrasonic detection sensor is mainly responsible for detecting the ultrasonic signal generated by the violent collision between electrons when the discharge occurs inside the equipment.
[0014] The pulse current detection sensor further comprises a capacitor embedded in the ceramic insulator, a display unit and a detection impedance.
[0015] The pulse current detection sensor mainly utilizes the capacitor of the ceramic insulator of the electric charging display device, avoids the direct action of the power frequency high voltage on the detection impedance, provides a loop for the pulse current generated by the partial discharge, and realizes the partial discharge detection.
[0016] The signal conditioning module is independent of the data processing module and comprises an amplification circuit module and a filter circuit module.
[0017] The signal conditioning module is mainly responsible for the band-pass filtering and amplification of the partial discharge signal. The frequency range of the switch cabinet ultrasonic detection method is 20 kHz-200 kHz; the frequency range of the pulse current method is 10 kHz-500 kHz. The frequency range of the pulse current detection method contains the frequency range of the ultrasonic detection method, so the same signal conditioning circuit can be adopted to realize the amplification and filtering of the partial discharge signal.
[0018] The data processing module comprises a high-speed signal acquisition circuit, an FPGA chip, a main control chip, a power module, a LoRa communication module and an SD storage module; the high-speed signal acquisition circuit is connected with the main control chip through the FPGA chip; the main control chip is connected with an edge computing gateway through the LoRa communication module; the power module and the SD storage module are connected with the main control chip respectively. The high-speed signal acquisition circuit mainly comprises an ADC08D1000 chip, an amplification circuit AD8009 chip, a single-ended to differential converter ADA4939 chip, a high-voltage module and a power chip. The main control chip adopts a microprocessor MSP430F6767 type single-chip microcomputer.
[0019] The utility model discloses a data processing module core is microprocessor MSP430F6767 type singlechip, is mainly responsible for completing ADC data conversion, data processing and analysis, data storage, data display and data transmission etc. To guarantee sampling signal precision, the high -speed signal acquisition circuit is with ADC08D1000 as the core. Because microprocessor operating frequency can not satisfy high -speed signal acquisition circuit, therefore uses FPGA and high -speed signal acquisition circuit to communicate first, and then FPGA sends the data that gathers to microprocessor and handles.
[0020] The utility model further illustrates that the PC host computer is power internet of things monitoring system, can carry out the analysis to the collected partial discharge signal data, and then realizes the diagnosis of partial discharge type.
[0021] The main body structure of the multi-modal sensing high-voltage switch cabinet insulation fault diagnosis device is a cuboid structure, wherein the front panel and the rear panel are rubber panels, the front panel is provided with two SMA interfaces, and the rear panel is provided with a LoRa interface and a power external connection / charging interface; the other four panels are all aluminum metal panels. Four L-shaped angle bars are further fixed at the bottom four corners through screws, for fixing and mounting the device.
[0022] The utility model has the advantages of:
[0023] The utility model constructs the multi-source heterogeneous sensing fusion system of pulse current method and ultrasonic detection, forms the composite detection system with time-frequency-space multidimensional feature extraction capability: first, based on the high sensitivity characteristic of pulse current method, realizes the accurate quantitative characterization of the discharge amount of insulation defects such as electric tree branch discharge and surface discharge, and simultaneously, combining the anti-electromagnetic interference advantage of ultrasonic detection, constructs the double-channel verification mechanism in the electromagnetic noise environment. This multi-modal fusion strategy not only retains the quantitative detection capability of pulse current method, but also enhances the diagnosis confidence through the spatial positioning characteristic of ultrasonic detection, significantly improves the insulation fault detection robustness under complex working conditions. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 It is the system overall architecture of an embodiment of the utility model;
[0025] Figure 2 It is primary wiring schematic drawing of live display device;
[0026] Figure 3 It is the basic principle of pulse current method partial discharge detection;
[0027] Figure 4 It is the amplification circuit module in signal conditioning module;
[0028] Figure 5This is the frequency-gain curve of the INA129 instrumentation amplifier;
[0029] Figure 6 This refers to the filter circuit module within the signal conditioning module.
[0030] Figure 7 This describes the overall structure of the high-speed signal acquisition circuit.
[0031] Figure 8 This is a topology diagram of the communication between the FPGA and the high-speed signal acquisition circuit.
[0032] Figure 9 For the MSP430F6767 microcontroller and its peripheral circuits;
[0033] Figure 10 This is the LoRa wireless transmission module circuit;
[0034] Figure 11 Power supply circuit for LoRa;
[0035] Figure 12 A simplified geometric diagram of a multimodal fault sensing device;
[0036] Figure 13 This is side A of the multimodal fault sensing device;
[0037] Figure 14 This is side B of the multimodal fault sensing device. Detailed Implementation
[0038] The present invention will be further described below with reference to the accompanying drawings.
[0039] Example:
[0040] A multimodal sensing high-voltage switchgear insulation fault diagnosis device, such as Figure 1 As shown, the system includes a partial discharge signal detection module, a signal conditioning module, a data processing module, an edge computing gateway, and a PC host computer. The partial discharge signal detection module includes an ultrasonic detection sensor and a pulse current detection sensor, which are respectively connected to the signal conditioning module via radio frequency signal lines. The signal conditioning module is connected to the data processing module via a radio frequency coaxial cable. The data processing module and the edge computing gateway transmit data via a LoRa communication network. The edge computing gateway and the PC host computer transmit data via a 4G or 5G network.
[0041] This embodiment further illustrates that the ultrasonic detection sensor is a piezoelectric ultrasonic sensor and is attached to the cabinet of the high-voltage switchgear.
[0042] In the embodiment, the ultrasonic detection sensor is mainly responsible for detecting the ultrasonic signal generated by the violent collision between electrons when discharge occurs inside the equipment. It selects the piezoelectric ultrasonic sensor commonly used in the field of partial discharge detection. It works by using the piezoelectric effect of piezoelectric materials. When the mechanical wave generated by partial discharge acts on the piezoelectric ceramic, the mechanical wave is converted into pressure, causing the ceramic sheet to stretch and contract. The two surfaces of the ceramic sheet generate electric charges of opposite polarity. The more intense the contraction and expansion of the ceramic sheet, the more electric charges are generated. These electric charges are converted into voltage and output. Through the coaxial cable, it can be measured and recorded by an oscilloscope and other devices, thereby realizing the conversion of sound and electricity, i.e. converting the ultrasonic signal generated by partial discharge into an electric signal.
[0043] The embodiment further illustrates that the pulse current detection sensor includes a capacitor embedded in a ceramic insulator, a display unit, and a detection impedance; the capacitor is connected in series with the display unit, and the detection impedance is connected in parallel with the display unit.
[0044] In the embodiment, the pulse current detection sensor mainly uses the capacitor of the ceramic insulator of the live display device to provide a loop for the pulse current generated by partial discharge while avoiding the direct action of power frequency high voltage on the detection impedance, thereby realizing partial discharge detection. The basic principle is as shown in Figure 2 and Figure 3 . Figure 2 It is a schematic diagram of the primary wiring of the live display device. Figure 2 In the embodiment, C k is a capacitor embedded in a ceramic insulator. The capacitance value is generally 115 pF, which presents high impedance to power frequency excitation, but presents low impedance to high-frequency pulse excitation generated by partial discharge. Therefore, the partial discharge signal in the high-voltage switch cabinet can be coupled through the capacitor. Figure 2 In the embodiment, C ie and R ie are the equivalent circuit of the indicator light. The detection impedance can be connected in parallel across the indicator light, as shown in Figure 3 : The pulse current acts on the detection impedance, which appears as a pulse voltage signal U d (t). After transmission, collection, amplification, and display processing, the partial discharge generated by the equipment can be determined. When the primary equipment generates partial discharge, a transient voltage change ΔU will occur across the test capacitor C x . At this time, a pulse current i will be generated in the loop, which is coupled to the detection impedance Z d through the coupling capacitor (ceramic insulator capacitor) C k , which appears as a pulse voltage signal U d (t). After transmission, collection, amplification, and display processing, some basic parameters of the partial discharge generated by the equipment can be determined.
[0045] After the ultrasonic sensing detection unit and the pulse current detection unit complete the detection of partial discharge signals, the partial discharge signals obtained by the different detection units are sent to the signal conditioning module through the radio frequency signal line.
[0046] This embodiment further illustrates that the signal conditioning module is independent of the data processing module and includes an amplification circuit module and a filtering circuit module.
[0047] In this embodiment, the signal conditioning module is mainly responsible for bandpass filtering and amplification of the partial discharge signal. The frequency range of the ultrasonic detection method for switchgear is 20kHz to 200kHz; the frequency range of the pulse current method is 10kHz to 500kHz. The frequency range of the pulse current detection method includes that of the ultrasonic detection method, therefore the same signal conditioning circuit can be used to amplify and filter the partial discharge signal.
[0048] The amplifier circuit module uses the INA129 low-power precision instrumentation operational amplifier manufactured by Texas Instruments (TI), which features low offset voltage, low drift, low input bias current, and low noise. The gain formula for the INA129 operational amplifier is:
[0049]
[0050] In the formula, G is the amplification factor of the INA129 instrumentation amplifier, and R = 49.4kΩ is the sum of the feedback resistors of the two internal amplifiers, which has the advantages of high precision and low temperature drift. G An external resistor is used; changing the value of the external resistor can change the amplification factor.
[0051] in accordance with Figure 5 The frequency-gain curve of the INA129 instrumentation amplifier is shown. As can be seen from the figure, considering that the frequency band of the amplified signal will be severely reduced when the amplification factor G is too large, the resistance value of the external resistor is selected as 750Ω in this embodiment, and the amplification factor is 67dB.
[0052] To ensure signal integrity as much as possible, the filtering circuit module uses a Butterworth bandpass filter, specifically the NE5532 integrated operational amplifier from Texas Instruments (TI) designed as an active bandpass Butterworth filter. The following formula is used for calculation... Figure 6 The values of resistors R1 to R8 and capacitors C1 to C4 are specified. According to the design manual, C1 = C2 = C3 = C4 = 1nF.
[0053]
[0054] In the formula, f cH Given a high-pass cutoff frequency of 500kHz, R3 = R4 = 820Ω; cLThe high-pass cutoff frequency is 10kHz, R7 = R8 = 820Ω; Q is the filter quality factor, with a value of 0.8; A vp Given the gain of a single-stage op-amp, we can further determine that R1 = 5kΩ, R2 = 3kΩ, R5 = 47kΩ, and R6 = 27kΩ.
[0055] After the partial discharge signal is acquired, amplified, and filtered, the signal is sent to the data processing module via an RF coaxial cable.
[0056] This embodiment further illustrates, as follows: Figure 1 As shown, the data processing module includes a high-speed signal acquisition circuit, an FPGA chip, a main control chip, a power supply module, a LoRa communication module, and an SD storage module. The high-speed signal acquisition circuit is connected to the main control chip via the FPGA chip. The main control chip is connected to the edge computing gateway via the LoRa communication module. The power supply module and the SD storage module are respectively connected to the main control chip. Figure 7 As shown, the high-speed signal acquisition circuit mainly consists of an ADC08D1000 chip, an AD8009 amplifier chip, an ADA4939 single-ended to differential converter chip, a high-voltage module, and a power supply chip. The main control chip is an MSP430F6767 microcontroller.
[0057] In this embodiment, the core of the data processing module is a microcontroller, specifically an MSP430F6767, primarily responsible for ADC data conversion, data processing and analysis, data storage, data display, and data transmission. To ensure the accuracy of the sampled signal, the high-speed signal acquisition circuit uses an ADC08D1000 as its core. Since the microprocessor's operating frequency cannot meet the requirements of the high-speed signal acquisition circuit, an FPGA is first used to communicate with the high-speed signal acquisition circuit. The FPGA then sends the acquired data to the microprocessor for processing (the circuit topology for this part is as follows). Figure 8 (As shown).
[0058] Figure 9 In this system, the main control chip has a crystal oscillator of 32.768kHz, the system power supply voltage is 3.3V, the ADC reference voltage is 1.65V, and the system power supply voltage is monitored by VCC-DETECT, which can monitor whether the system voltage is normal at any time.
[0059] This embodiment is equipped with LoRa wireless communication technology to transmit data to the edge computing gateway. The LoRa wireless transmission module circuit is as follows: Figure 10As shown. In addition, since the power consumption of the LoRa wireless data transmission module is about 150mW when transmitting data, and the standby power consumption is not higher than 10μW, the power consumption of the LoRa module is large when working. In order to realize low power consumption, a power supply circuit of the LoRa module needs to be designed, which is opened when the monitoring device needs to upload data, and is closed after the data transmission is completed, such as Figure 11 As shown.
[0060] After the LoRa uploads the partial discharge data to the edge computing gateway, the gateway transmits it to the "power internet monitoring system" through 4G, and then realizes the diagnosis of the type of partial discharge.
[0061] As shown in Figures 12-14 The main structure of the multi-modal sensing high-voltage switch cabinet insulation fault diagnosis device of the embodiment is a cuboid structure, wherein the front panel (A surface) and the rear panel (B surface) are rubber panels, the front panel (A surface) is provided with two SMA interfaces (ultrasonic wave detection coaxial line interface and pulse current detection coaxial line interface), and the rear panel (B surface) is provided with a LoRa interface and a power supply external connection / charging interface; the remaining four panels are aluminum metal panels. Four L-shaped angle bars are respectively fixed at the bottom four corners through screws, which are used for fixing and installing the device.
[0062] Obviously, the above embodiments are only examples for clearly illustrating the utility model, and are not a limitation on the implementation of the utility model. For ordinary skilled persons in the art, other different forms of changes or variations can be made on the basis of the above description; here, it is not necessary and impossible to exhaust all the embodiments; the obvious changes or variations derived therefrom are still within the protection scope of the utility model.
Claims
1. A multi-modal perception high voltage switchgear insulation fault diagnostic apparatus, characterized in that: The partial discharge signal detection module, the signal conditioning module, the data processing module, the edge computing gateway and the PC host computer are included. The partial discharge signal detection module includes ultrasonic detection sensors and pulse current detection sensors, and is connected with the signal conditioning module through radio frequency signal lines respectively. The signal conditioning module is connected with the data processing module through radio frequency coaxial lines. The data processing module and the edge computing gateway transmit data through a LoRa communication network. The edge computing gateway and the PC host computer transmit data through a 4G or 5G network.
2. The multi-modal perception high voltage switchgear insulation fault diagnostic apparatus as claimed in claim 1, wherein: The ultrasonic detection sensors are piezoelectric ultrasonic sensors and are attached to the cabinet of the high-voltage switch cabinet.
3. The multi-modal perception high voltage switchgear insulation fault diagnostic apparatus as claimed in claim 1, wherein: The pulse current detection sensor includes a capacitor embedded in a ceramic insulator, a display unit and a detection impedance; the capacitor is connected in series with the display unit, and the detection impedance is connected in parallel with the display unit.
4. The multi-modal perception high voltage switchgear insulation fault diagnostic apparatus as claimed in claim 1, wherein: The signal conditioning module is independent of the data processing module and includes an amplification circuit module and a filter circuit module.
5. The multi-modal perception high voltage switchgear insulation fault diagnostic apparatus as claimed in claim 1, wherein: The data processing module includes a high-speed signal acquisition circuit, an FPGA chip, a main control chip, a power module, a LoRa communication module and an SD storage module; the high-speed signal acquisition circuit is connected with the main control chip through the FPGA chip; the main control chip is connected with the edge computing gateway through the LoRa communication module; the power module and the SD storage module are connected with the main control chip respectively.
6. The multi-modal perception high voltage switchgear insulation fault diagnostic apparatus as claimed in claim 5, wherein: The high-speed signal acquisition circuit mainly consists of an ADC08D1000 chip, an amplification circuit AD8009 chip, a single-ended to differential converter ADA4939 chip, a high-voltage module and a power supply chip.
7. The multi-modal perception high voltage switchgear insulation fault diagnostic apparatus as claimed in claim 5, wherein: The main control chip adopts a microprocessor MSP430F6767 single-chip microcomputer.