Multi-parameter active pressure release protection device for extra-high voltage transformer

Abstract

The application belongs to the technical field of power equipment protection, and provides a multi-parameter active pressure release protection device for an extra-high voltage transformer, which comprises a mechanical release module, a digital monitoring module, a signal processing module and an integrated protection structure, and each module is rigidly connected through a flange; the mechanical release module comprises a mechanical release valve body, an oil injection port, a diaphragm disc, a spring assembly, a junction box and a pressure sensor interface. The application realizes fault early warning through a pressure gradient algorithm, is 0.5s-2s earlier than a traditional mechanical action, avoids deformation or explosion of an oil tank due to sudden pressure rise, improves performance parameters, is suitable for extreme environments, supports digital operation and maintenance, and is more convenient to install.

Description

Technical Field

[0001] This invention belongs to the field of power equipment protection technology, specifically a multi-parameter active pressure relief protection device for ultra-high voltage transformers. Background Technology

[0002] Ultra-high voltage transformers are core equipment in power systems. Abnormal internal pressure in their oil tanks (such as internal short circuits or insulation breakdowns) can easily lead to tank deformation or even explosion. Pressure relief devices are needed to ensure safety. However, traditional transformer pressure relief valves use mechanical pressure triggering structures, and their technical defects are mainly reflected in the following aspects: Limited monitoring capabilities: They can only provide mechanical action signals, lack digital monitoring and data analysis capabilities, cannot track pressure change trends in real time, and are difficult to predict faults. Response lag: Low pressure monitoring accuracy (typically deviation of ±5 kPa or more), fixed action threshold, and inability to dynamically adjust response time according to the rate of pressure change, which can easily lead to untimely protection. Insufficient mechanical performance: limited oil discharge (traditional diameter is mostly 100mm~150mm), poor fatigue resistance of spring material (e.g., tensile strength of 65Mn spring ≤1200MPa), insufficient diaphragm sealing performance (vacuum withstand capability ≤10Pa), and easy to leak or malfunction after long-term operation. Poor environmental adaptability: It lacks anti-electromagnetic interference design, has a high failure rate in the vibration environment (4-1000Hz) of UHV converter transformers, and its protection level is mostly IP54, which cannot adapt to high humidity, dusty and highly corrosive environments. Lack of data interaction: It is impossible to link with the backend monitoring system, stress data cannot be stored and traced, and it is difficult for operation and maintenance personnel to analyze the cause of stress anomalies.

[0003] To address these issues, those skilled in the art have proposed a multi-parameter active pressure relief protection device for ultra-high voltage transformers. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a multi-parameter active pressure relief protection device for ultra-high voltage transformers, thereby resolving the issues mentioned in the prior art.

[0005] A multi-parameter active pressure release protection device for ultra-high voltage transformers includes a mechanical release module, a digital monitoring module, and a signal processing module. The mechanical release module comprises a mechanical release valve body, an oil injection port, a diaphragm disc, a spring assembly, a junction box, and a pressure sensor interface. The junction box is located on the top of the mechanical release valve body, and the pressure sensor interface is located on the outside of the junction box. An oil injection port is located on the side of the mechanical release valve body, and a spring assembly is located inside the oil injection port. A diaphragm disc is located at the bottom of the spring assembly. The digital monitoring module integrates a pressure sensor. The signal processing module incorporates a pressure gradient algorithm.

[0006] Preferably, a spring pressure plate is provided on the top of the spring assembly, the spring pressure plate is fixedly connected to the spring assembly, a sliding rod is provided between the spring pressure plate and the top of the mechanical release valve body, the spring assembly and the spring pressure plate move inside the mechanical release valve body through the sliding rod, a valve seat is provided at the bottom of the spring assembly, the valve seat is fixedly installed at the bottom of the mechanical release valve body, and the valve seat is fixedly connected to the bottom of the spring assembly.

[0007] Preferably, it also includes an integrated protective structure, which is specifically a complete housing. The integrated protective structure meets the IP67 protection level and C5M corrosion resistance level, integrates EMC anti-interference design and wiring cavity anti-condensation structure, and passes EMC anti-interference tests including electrostatic discharge, radio frequency electromagnetic field radiation and fast transient burst.

[0008] Preferably, the sampling frequency of the pressure gradient algorithm is 1kHz, and it includes three action thresholds: 0.5s when dP / dt≥5kPa / s, 1s when 2kPa / s<dP / dt<5kPa / s, and 2s when dP / dt≤2kPa / s. The static pressure over-limit threshold is set to 80kPa, and the normal operating pressure is 0~50kPa.

[0009] Preferably, the mechanical release module further includes a silver-nickel alloy contact switch, with the contacts integrating a fluororubber sealing ring and a labyrinthine waterproof oil channel.

[0010] Preferably, the digital monitoring module supports real-time communication with the background monitoring system, the pressure history data storage period is ≥3 months, and it can retrieve pressure change curves with a time resolution of 1 second and action event records including action time, pressure peak, and recovery time.

[0011] Preferably, the pressure sensor is a diffused silicon pressure sensor, model MEASMS5837-30BA, which is used in conjunction with an AD7190 24-bit ADC chip and a second-order Butterworth filter is used to eliminate high-frequency noise.

[0012] Preferably, the spring assembly uses a 55 silicon-chromium alloy spring, through 10 6 After several compression cycles and load tests of 500N to 1500N, the residual deformation is ≤0.5mm, and the salt spray resistance test is ≥1000 hours.

[0013] Preferably, the anti-condensation structure of the wiring cavity includes a Gore-Tex waterproof and breathable membrane with an air permeability ≥500ml / m³. 2 • After 24 hours, with a 5WPTC heating element, there is no condensation at 50℃ and 90%RH, and the insulation resistance is ≥100MΩ.

[0014] Preferably, the pressure gradient algorithm achieves dynamic response through the following steps: Step 1: Collect pressure data at a sampling frequency of 1kHz and calculate the rate of pressure change per unit time; Step 2: Preset 3-level action thresholds; specifically: when dP / dt≥5kPa / s, the action time is 0.5s; when 2kPa / s<dP / dt<5kPa / s, the action time is 1s; when dP / dt≤2kPa / s, the action time is 2s. Step 3: Combine the absolute value of static pressure to trigger graded early warning, and output 4mA~20mA analog signal and RS485 digital signal.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. Active protection upgrade: Fault warning is achieved through pressure gradient algorithm, which is 0.5s to 2s earlier than traditional mechanical action, to avoid deformation or explosion of oil tank due to sudden pressure rise.

[0016] 2. Performance parameters improved dramatically: fuel displacement ≥ 1.2m 3 / min (40% improvement), opening pressure accuracy ±2kPa (60% improvement), contact switch life ≥2000 cycles (100% extension), mean time between failures (MTBF) ≥80000 hours.

[0017] 3. Extreme environment adaptation: The IP67+C5M design can operate for a long time in coastal high humidity (>95%RH), strong electromagnetic interference, and 4~1000Hz vibration scenarios, with sensor output fluctuation ≤0.5kPa.

[0018] 4. Digital operation and maintenance support: Pressure data is uploaded to the SCADA system in real time, and the pressure curve and action events (time, peak, recovery time) can be traced with a resolution of 1 second, reducing operation and maintenance costs by 30%.

[0019] 5. Improved ease of installation: The integrated structure weighs ≤15kg (40% lighter), the installation height is reduced by 30%, the wiring time is shortened by 50%, and it is compatible with the retrofitting of existing transformers. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the mechanical release module in the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the mechanical release module in the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the internal structure of the mechanical release module in this invention; Figure 4 This is a schematic diagram of the digital monitoring module in this invention; Figure 5 This is a flowchart of the pressure gradient algorithm in this invention.

[0021] In the picture: 1. Mechanical release valve body; 2. Pressure sensor interface; 3. Junction box; 4. Oil injection port; 5. Spring assembly; 6. Diaphragm; 7. Limit rod; 8. Spring pressure seat; 9. Valve plate. Detailed Implementation

[0022] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0023] As attached Figure 1 To be continued Figure 5 As shown: Example 1: This invention provides a multi-parameter active pressure release protection device for ultra-high voltage transformers, comprising a mechanical release module, a digital monitoring module, a signal processing module, and an integrated protection structure. Each module is rigidly connected via flanges; the interface conforms to GB / T5273 M20×1.5 thread. The mechanical release module includes a mechanical release valve body 1, an oil injection port 4, a diaphragm disc 6, a spring assembly 5, a junction box 3, and a pressure sensor interface 2. The mechanical release valve body 1 is made of Q345R pressure vessel special steel plate (8mm thick) machined by CNC lathe, with an inner wall roughness Ra≤1.6μm to prevent impurities from accumulating and causing the diaphragm disc 6 to jam. A junction box 3 is installed on the top of the mechanical release valve body 1. The junction box 3 is made of flame-retardant ABS plastic (compliant with UL94V0 flame-retardant standard), with a protection rating of IP67, and internally equipped with Weidmuller WDU anti-loosening wiring. The terminals (rated current 16A, rated voltage AC250V, contact resistance ≤5mΩ) support integrated wiring for signal, power, and grounding, reducing wiring time by 50% compared to traditional devices (from 2 hours to 1 hour). A pressure sensor interface 2 is located on the outside of the junction box 3, with an M20×1.5 thread and a built-in fluororubber sealing ring (oil-resistant temperature ~20℃~200℃) to ensure good airtightness after sensor installation (pressure drop ≤0.005MPa after passing through 0.1MPa compressed air and holding for 30 minutes). An oil spray port 4 with a diameter of 170mm and a 60° diffusion angle design—verified through fluid dynamics simulation (ANSYS Fluent software)—ensures uniform oil mist diffusion during pressure relief, avoiding localized pressure concentration and increasing the oil discharge rate to ≥1.2m³. 3 / min (compared to 0.8–1.0 m / min of traditional devices) 3 ( / min increase of 20-50%), can accelerate 100m within 3 seconds 3The pressure in the volumetric oil tank drops from 100 kPa to below 60 kPa. An anti-backflow structure (rubber retainer ring) is installed inside the injector 4 to prevent oil mist from flowing back after pressure relief. A spring assembly 5 is installed inside the injector 4. The spring assembly 5 is made of 55 silicon-chromium alloy (chemical composition: C 0.52~0.60%, Si 1.20~1.60%, Cr 0.50~0.80%, Mn≤0.80%), with a spring diameter of 8 mm, a free length of 120 mm, a working length of 95 mm, and a compression stroke of 25 mm. A diaphragm disc 6 is installed at the bottom of the spring assembly 5. The diaphragm disc 6 is made of 2.5 mm thick 316 stainless steel. Made of stainless steel (containing 10% nickel and 17% chromium), it is CNC stamped (with a radius of 5mm to avoid stress concentration) and then annealed at 1050℃ for 2 hours (holding time 2 hours, cooling rate 5℃ / min) to ensure a yield strength ≥500MPa and an elongation ≥20%. It can withstand a pressure of 0.15MPa without permanent deformation. The sealing surface between the diaphragm 6 and the valve seat adopts laser cladding technology (cladding material is Stellite 6 alloy), with a sealing surface roughness Ra≤0.8μm and a vacuum withstand capability ≤1Pa (superior to the 10Pa index of traditional devices). It has no leakage during long-term operation. A spring pressure plate (made of 304 stainless steel, 10mm thick) is provided on the top of the spring assembly 5. The spring pressure plate is fixedly connected to the spring assembly 5. A sliding rod (10mm in diameter, made of 20CrMnTi, chrome-plated) is provided between the spring pressure plate and the top of the mechanical release valve body 1. The spring assembly 5 and the spring pressure plate move inside the mechanical release valve body 1 through the sliding rod. The clearance between the sliding rod and the spring pressure plate is 0.02~0.05mm to ensure that the spring assembly 5 and the diaphragm 6 move smoothly along the axial direction without jamming or offset. A valve seat is provided at the bottom of the spring assembly 5. The valve seat is fixedly installed at the bottom of the mechanical release valve body 1 and is fixedly connected to the bottom of the spring assembly 5. The valve seat is fastened to the bottom of the mechanical release valve body 1 with bolts (8.8 grade high strength bolts) with a torque ≥40N・m to prevent loosening due to vibration. The sliding rod and the spring pressure plate can ensure that the movement trajectory of the spring assembly 5 and the diaphragm 6 is stable and without offset. The digital monitoring module integrates a pressure sensor with a range of 0–200 kPa and an accuracy of ±1 kPa. It features a built-in temperature compensation circuit from -40℃ to 125℃ and outputs 4mA–20mA analog signals and RS485 digital signals. The signal processing module incorporates a pressure gradient algorithm based on an STM32H743 microcontroller, capable of calculating the pressure change rate dP / dt and triggering a graded response of 0.5–2 seconds. The integrated protective structure meets IP67 protection and C5M corrosion resistance standards. It integrates EMC anti-interference design and a wiring cavity anti-condensation structure. The integrated protective structure has passed eight EMC anti-interference tests, including electrostatic discharge (±8kV contact, ±15kV air), radio frequency electromagnetic field radiation (10V / m), and fast transient bursts (±2kV power supply, ±1kV signal), conforming to GB / T17626 standards.

[0024] Working principle: The device is installed after the oil tank of the UHV transformer. The digital monitoring module collects the static pressure of the oil tank in real time, and the temperature compensation circuit corrects the error (accuracy ±1kPa) in an environment of -40℃~125℃; the signal processing module calculates dP / dt at a frequency of 1kHz. When dP / dt≥5kPa / s and static pressure≥80kPa, a trigger signal is output within 0.5 seconds; Triggered in 1 second when 2 kPa / s < dP / dt < 5 kPa / s and static pressure ≥ 80 kPa; Triggered after 2 seconds when dP / dt≤2kPa / s and static pressure≥80kPa; After receiving the signal, the mechanical release module activates the spring-driven diaphragm 6 to open, achieving a flow rate of ≥1.2m through the 170mm diameter injection nozzle 4 with a 60° diffusion angle. 3 / min oil discharge volume for rapid pressure relief; at the same time, the digital module uploads pressure data (1-second resolution) and action events (time, peak value) to the SCADA system, with a storage period of ≥3 months, for maintenance personnel to trace and analyze.

[0025] Example 2: This example, based on Example 1, adds refined signal processing and data interaction functions. The sampling frequency of the pressure gradient algorithm is 1kHz, and it includes three action thresholds: 0.5s when dP / dt ≥ 5kPa / s, 1s when 2kPa / s < dP / dt < 5kPa / s, and 2s when dP / dt ≤ 2kPa / s. The static pressure over-limit threshold is set to 80kPa, and the normal operating pressure is 0-50kPa. The mechanical release module also includes a silver-nickel alloy contact switch, with integrated fluororubber sealing rings and labyrinth-type waterproof oil channels. The transformer has an IP67 rating and a labyrinthine waterproof oil channel. The labyrinthine channel consists of three layers of annular grooves, which can effectively prevent transformer oil and water vapor from entering the contacts. There is no leakage under 0.1MPa oil pressure. The contact switch is triggered by a "spring plate linkage": when the diaphragm plate 6 is opened, the spring plate drives the contacts to close, outputting a mechanical trigger signal, which is simultaneously fed back to the signal processing module to achieve "mechanical + electronic" dual trigger verification. The digital monitoring module supports real-time communication with the background monitoring system. The pressure history data storage period is ≥3 months, and the pressure change curve with a time resolution of 1s and the action event records including the action time, pressure peak, and recovery time can be retrieved.

[0026] The pressure gradient algorithm runs on the FreeRTOS real-time system of the STM32H743 microcontroller, dividing the pressure data into three levels: "normal (0-50kPa), warning (50-80kPa), and over-limit (≥80kPa)," with corresponding output of different indicator light signals (green / yellow / red). When the contact switch is triggered, in addition to mechanical pressure relief, an AC220V 16A control signal is simultaneously output to the transformer cooling system to achieve "pressure relief + cooling" coordinated protection. In EMC testing, under the radio frequency electromagnetic field radiation (10V / m) environment, the sensor output fluctuation is ≤0.4kPa, and there is no packet loss in RS485 data. The back-end system can remotely adjust the pressure threshold (such as setting the over-limit pressure to 75kPa) via the Modbus-RTU protocol without on-site disassembly.

[0027] Example 3: Based on Example 1, this example enhances reliability under extreme environments. The surface of the mechanical release valve body 1 is coated with an epoxy zinc-rich anti-corrosion coating (thickness ≥120μm), meeting the ISO12944-5C5M anti-corrosion grade requirements. It withstands salt spray tests for ≥1000 hours (neutral salt spray chamber test, GB / T10125-2021 standard), allowing for long-term operation in high-humidity coastal environments. The pressure sensor uses a diffused silicon pressure sensor, model MEASMS5837-30BA. This sensor is based on the semiconductor piezoresistive effect principle (pressure changes cause changes in silicon wafer resistance, which are converted into electrical signals via a Wheatstone bridge). It has a range of 0~200kPa and an accuracy of ± With a pressure range of 1 kPa (80% improvement over traditional sensors ±5 kPa), and an operating temperature range of -40℃ to 125℃, the sensor incorporates a built-in temperature sensor (PT1000 platinum resistance thermometer) to collect ambient temperature data in real time, providing temperature compensation for pressure measurements. Addressing the temperature-sensitive nature of diffused silicon sensors (approximately 0.05 kPa error per 1℃ temperature change), a dual hardware and software temperature compensation circuit is designed: Hardware-wise, a PT1000 platinum resistance thermometer is used to collect ambient temperature data, and a differential amplifier circuit composed of operational amplifiers is used to correct the sensor output signal in real time; software-wise, based on an STM32H743 microcontroller, a piecewise linear interpolation algorithm is used to adjust the pressure measurement accuracy from -40℃ to 125℃. The temperature range of 0℃ to 125℃ is divided into 16 intervals, each with a preset compensation coefficient to ensure pressure measurement accuracy of ±1kPa across the entire temperature range. Combined with the AD7190 24-bit ADC chip, which boasts a conversion rate of 4.8kHz, 24-bit resolution, and an integral nonlinearity error ≤0.001%, it accurately converts the weak analog signal (mV level) output by the sensor into a digital signal. To eliminate high-frequency noise (frequency >10Hz) generated by transformer vibration and electromagnetic interference, a second-order Butterworth low-pass filter is incorporated into the circuit, with a cutoff frequency of 10Hz and an attenuation rate of ~40dB / decade. Testing shows that the sensor output fluctuation after filtering is ≤0.5kPa (within 1...). Under 0V / m radio frequency electromagnetic field radiation conditions, spring assembly 5 uses a 55 silicon-chromium alloy spring. Under 106 compression cycles (corresponding to a 20-year operating cycle) and a load of 500N~1500N (covering normal operation and fault conditions), the residual deformation is ≤0.5mm (only 1 / 3 of that of a traditional 65Mn spring). Within a temperature range of -40℃~125℃, the elastic coefficient change rate is ≤5%, ensuring stable opening pressure accuracy. The spring surface undergoes a double-layer anti-corrosion treatment of phosphating and electrophoresis (coating thickness ≥30μm), with a salt spray resistance test of ≥1000 hours and no rust. The anti-condensation structure of the wiring cavity includes a Gore-Tex waterproof and breathable membrane with a breathability of ≥500ml / m³. 2 • After 24 hours, with a 5WPTC heating element, no condensation occurred at 50℃ and 90%RH, and the insulation resistance was ≥100MΩ. The pressure gradient algorithm achieved dynamic response through the following steps: Step 1: Collect pressure data at a sampling frequency of 1kHz and calculate the rate of pressure change per unit time; Step 2: Preset 3-level action thresholds; specifically: when dP / dt≥5kPa / s, the action time is 0.5s; when 2kPa / s<dP / dt<5kPa / s, the action time is 1s; when dP / dt≤2kPa / s, the action time is 2s. Step 3: Combine the absolute value of static pressure to trigger graded early warning, and output 4mA~20mA analog signal and RS485 digital signal.

[0028] The pressure sensor underwent cyclic testing at -40℃ and 125℃ (each for 2 hours), maintaining a measurement accuracy of ±1 kPa. After being placed in a 50℃, 90%RH constant temperature and humidity chamber for 48 hours, no condensation was observed in the wiring cavity, and the insulation resistance was ≥100 MΩ (measured with a 500V megohmmeter). A 4Hz~1000Hz sweep frequency vibration test (acceleration 55 m / s²) was also performed. 2 After 1 hour, the bolt preload decreases by ≤5%, the mechanical structure is not loose, and the contact switch does not malfunction. During installation, Weidmüller WDU anti-loosening terminals are used to achieve one-time wiring of signal, power and ground wires, reducing the on-site installation time from the traditional 2 hours to 1 hour.

[0029] Working principle: A 2.5mm 316 stainless steel plate is CNC stamped (R5mm rounded corners), and the edges are laser-welded before annealing at 1050℃ for 2 hours (ensuring yield strength ≥500MPa) to form diaphragm plate 6; an 8mm diameter 55 silicon-chromium alloy wire coil spring (free length 120mm, working length 95mm) is electrophoretically treated and then assembled with diaphragm plate 6 into a 170mm fuel injector 4-diameter valve body. The spring compression stroke is adjusted to 25mm to ensure an opening pressure deviation of ±2kPa; the contact switch uses AgNi10 contacts with rated parameters of AC220V 16A and DC220V 1A, a mechanical life of ≥2000 cycles, and integrates a fluororubber sealing ring and a labyrinth channel, meeting IP67 standards. The MEASMS5837-30BA sensor and AD7 are integrated into the valve body. The 190ADC chip is soldered, connected to a second-order Butterworth filter (cutoff frequency 10Hz), and after soldering the temperature compensation circuit, it is encapsulated in a 316L stainless steel housing. It is rigidly connected to the mechanical release valve body via a Q235B galvanized flange. The pressure gradient algorithm (C language, code size ≤64KB) is programmed into the STM32H743 microcontroller, and sensor data is read via DMA. The RS485 signal is output through an ADUM1401 isolation chip (2.5kV isolation) to ensure a packet loss rate of ≤0.1% for 1km transmission (9600bps). The housing is coated with an anti-corrosion coating, and a Gore-Tex diaphragm and PTC heating element are installed in the wiring cavity. The entire system passes the EMC electrostatic discharge test (±8kV contact), and the sensor output fluctuation is ≤0.3kPa.

[0030] The embodiments of the present invention are given for the purposes of illustration and description. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made by those skilled in the art to the above embodiments within the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-parameter active pressure relief protection device for ultra-high voltage transformers, characterized in that: The system includes a mechanical release module, a digital monitoring module, and a signal processing module. The mechanical release module includes a mechanical release valve body (1), an oil injection port (4), a diaphragm disc (6), a spring assembly (5), a junction box (3), and a pressure sensor interface (2). The mechanical release valve body (1) has a junction box (3) on its top and a pressure sensor interface (2) on its outer side. The mechanical release valve body (1) has an oil injection port (4) on its side and a spring assembly (5) inside the oil injection port (4). The diaphragm disc (6) is located at the bottom of the spring assembly (5). The digital monitoring module integrates a pressure sensor. The signal processing module has a built-in pressure gradient algorithm.

2. The multi-parameter active pressure relief protection device for ultra-high voltage transformers as described in claim 1, characterized in that, A spring pressure plate (8) is provided on the top of the spring assembly (5). The spring pressure plate (8) is fixedly connected to the spring assembly (5). A sliding rod (7) is provided between the spring pressure plate (8) and the top of the mechanical release valve body (1). The spring assembly (5) and the spring pressure plate (8) move inside the mechanical release valve body (1) through the sliding rod (7). A valve seat (9) is provided at the bottom of the spring assembly (5). The valve seat (9) is fixedly installed at the bottom of the mechanical release valve body (1) and is fixedly connected to the bottom of the spring assembly (5).

3. The multi-parameter active pressure relief protection device for ultra-high voltage transformers as described in claim 1, characterized in that: It also includes an integrated protective structure, which is specifically the entire housing. The integrated protective structure meets the IP67 protection level and C5M corrosion resistance level, and integrates EMC anti-interference design and anti-condensation structure for the wiring cavity. The integrated protective structure passes EMC anti-interference tests including electrostatic discharge, radio frequency electromagnetic field radiation and fast transient burst.

4. The multi-parameter active pressure relief protection device for ultra-high voltage transformers as described in claim 1, characterized in that: The sampling frequency of the pressure gradient algorithm is 1kHz, and it includes three action thresholds: 0.5s when dP / dt≥5kPa / s, 1s when 2kPa / s<dP / dt<5kPa / s, and 2s when dP / dt≤2kPa / s. The static pressure over-limit threshold is set to 80kPa, and the normal operating pressure is 0~50kPa.

5. The multi-parameter active pressure relief protection device for ultra-high voltage transformers as described in claim 1, characterized in that: The mechanical release module also includes a silver-nickel alloy contact switch, the contacts of which are integrated with fluororubber sealing rings and labyrinth-type waterproof oil channels.

6. The multi-parameter active pressure relief protection device for ultra-high voltage transformers as described in claim 1, characterized in that: The digital monitoring module supports real-time communication with the background monitoring system, and the pressure history data storage period is ≥3 months. It can retrieve pressure change curves with a time resolution of 1 second and action event records including action time, pressure peak, and recovery time.

7. The multi-parameter active pressure relief protection device for ultra-high voltage transformers as described in claim 1, characterized in that: The pressure sensor is a diffused silicon pressure sensor, model MEASMS5837-30BA, which is used in conjunction with an AD7190 24-bit ADC chip and a second-order Butterworth filter to eliminate high-frequency noise.

8. The multi-parameter active pressure relief protection device for ultra-high voltage transformers as described in claim 1, characterized in that: The spring assembly (5) uses a 55 silicon-chromium alloy spring, which is connected to a 10 6 After several compression cycles and load tests of 500N to 1500N, the residual deformation is ≤0.5mm, and the salt spray resistance test is ≥1000 hours.

9. The multi-parameter active pressure relief protection device for ultra-high voltage transformers as described in claim 3, characterized in that: The anti-condensation structure of the wiring cavity includes a Gore-Tex waterproof and breathable membrane with a breathability of ≥500ml / m³. 2 • 24h, also includes 5WPTC heating element, no condensation in 50℃, 90%RH environment, insulation resistance ≥100MΩ.

10. The multi-parameter active pressure relief protection device for ultra-high voltage transformers as described in claim 1, characterized in that: The pressure gradient algorithm achieves dynamic response through the following steps: Step 1: Collect pressure data at a sampling frequency of 1kHz and calculate the rate of pressure change per unit time; Step 2: Preset 3-level action thresholds; specifically: when dP / dt≥5kPa / s, the action time is 0.5s; when 2kPa / s<dP / dt<5kPa / s, the action time is 1s; when dP / dt≤2kPa / s, the action time is 2s. Step 3: Combine the absolute value of static pressure to trigger graded early warning, and output 4mA~20mA analog signal and RS485 digital signal.

Images