Multi-parameter active protection gas relay

Abstract

The invention discloses a multi-parameter active protection gas relay which comprises a body, a double-floating-ball mechanical assembly arranged in a measurement and control cavity of the body and a multi-parameter monitoring module arranged on the body, and the double-floating-ball mechanical assembly comprises an upper floating ball and a lower floating ball which are arranged up and down. The upper floating ball and the lower floating ball are used for responding to liquid level information in the measurement and control cavity; the multi-parameter monitoring module comprises an active protection module, a liquid level monitoring unit and a hydrogen monitoring unit, and the liquid level monitoring unit is used for detecting and acquiring liquid level information in the measurement and control cavity to reflect the gas gathering amount; the hydrogen monitoring unit is used for detecting and acquiring the hydrogen content in oil and the hydrogen content in gas in the measurement and control cavity; the liquid level monitoring unit and the hydrogen monitoring unit are connected into the collecting end of the active protection module, and the active protection module correspondingly conducts graded protection action based on the liquid level information, the hydrogen content in oil and the hydrogen content in gas.

Description

Technical Field

[0001] This invention relates to the technical field of power equipment protection, and in particular to a multi-parameter active protection gas relay. Background Technology

[0002] Gas relays are core protection devices for transformers. They monitor changes in gas or oil flow caused by faults inside the transformer and trigger protective actions such as light gas alarms, heavy gas trips, or low oil level trips, which are crucial for the safe operation of transformers. However, traditional gas relays rely solely on two mechanical triggering conditions—gas volume (light gas) and oil flow velocity (heavy gas)—and cannot distinguish the nature of the fault. 1. Limited Monitoring Parameters: 1) Misjudgment of Air Ingress and Fault Gas: Air introduced during transformer oil filling and filtration accumulates in the relay, triggering a light gas alarm (gas volume ≥250mL). However, the composition of air (primarily nitrogen) is completely different from fault gases (hydrogen, methane, etc.), making it impossible for traditional solutions to identify, resulting in a high annual false alarm rate. 2) Inability to Distinguish Fault Types: Different faults, such as partial discharge (primarily hydrogen), overheating (primarily methane and ethylene), and arc faults (primarily acetylene), produce significantly different gas compositions. However, traditional relays only trigger based on gas volume, failing to provide maintenance personnel with fault location information and delaying repairs.

[0003] 2. Delayed Fault Early Warning: Traditional relays require the use of gas chromatographs (GC) or online oil chromatography monitoring systems (DGA) to analyze gas components, resulting in a fatal lag: 1) Lack of timeliness in offline detection: Traditional processes require manual oil sampling → laboratory testing, with a single analysis taking 4-8 hours and a sampling cycle typically lasting 1-3 months, failing to capture early gas characteristics of sudden faults (such as inter-turn short circuits). 2) The "passive waiting" limitation of online DGA: Even with online DGA, its detection principle still relies on the slow release of gas from the oil (degassing efficiency approximately 30%-50% / 24h). Concentration data for critical fault gases such as hydrogen lags behind the actual fault occurrence by more than 24 hours, leading to missed early warning windows.

[0004] Secondly, the protection logic of the relay is based on mechanical triggering with a fixed threshold, which cannot achieve "gradual handling" of faults. It lacks graded response capability through a "one-size-fits-all" action mode. In summary, the technical limitations of traditional gas relays have become a key bottleneck restricting the safe operation of transformers. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-parameter active protection gas relay that achieves accurate identification, early warning and graded protection of transformer faults through the coordinated design of mechanical structure and electronic monitoring.

[0006] To achieve the above objectives, the present invention provides a multi-parameter active protection gas relay, comprising a body, a dual-float mechanical assembly disposed in the measurement and control cavity of the body, and a multi-parameter monitoring module disposed on the body, wherein... The dual-float mechanical assembly includes an upper float and a lower float arranged vertically, which are used to respond to liquid level information in the measurement and control cavity; The multi-parameter monitoring module includes an active protection module, a liquid level monitoring unit, and a hydrogen monitoring unit. The liquid level monitoring unit is used to detect and acquire liquid level information in the measurement and control cavity to reflect the amount of gas accumulation. The hydrogen monitoring unit is used to detect and acquire the hydrogen content in the oil and the hydrogen content in the gas in the measurement and control cavity. The active protection module's acquisition terminals are respectively connected to the liquid level monitoring unit and the hydrogen monitoring unit, and the active protection module performs graded protection actions based on the liquid level information, the hydrogen content in the oil, and the hydrogen content in the gas.

[0007] Furthermore, the graded protection action is divided into a warning stage, an alarm stage, and a tripping stage, wherein, Warning phase: When the hydrogen content in the oil exceeds the rated threshold, a warning signal is triggered; Alarm phase: When the amount of gas accumulated exceeds the rated threshold and the hydrogen content in the gas exceeds the rated threshold, an alarm signal is triggered. Trip phase: When the liquid level information is lower than the preset lower limit value, a trip signal is triggered.

[0008] Furthermore, the active protection module calculates the hydrogen change rate in the oil and the hydrogen change rate in the gas based on the hydrogen content in the oil and the hydrogen content in the gas obtained by the continuous sampling of the hydrogen monitoring unit, and then performs corresponding protection actions based on the hydrogen change rate in the oil and / or the hydrogen change rate in the gas.

[0009] Furthermore, when the rate of change of hydrogen in the oil and / or the rate of change of hydrogen in the gas exceeds the rated threshold, a warning signal is triggered.

[0010] Furthermore, it also includes a display module installed on the outside of the main body for displaying the amount of gas accumulation, the hydrogen content in the oil, the hydrogen content in the gas, the rate of change of hydrogen in the oil, and the rate of change of hydrogen in the gas.

[0011] Furthermore, the upper and lower floating balls are made of solid stainless steel.

[0012] Furthermore, the dual-float mechanical assembly also includes an oil flow impact baffle located in the middle of the measurement and control cavity, which is used to reflect the oil flow velocity.

[0013] Furthermore, when the oil flow rate exceeds the rated threshold, the tripping phase is triggered.

[0014] Furthermore, a warning signal is triggered when the hydrogen content in the oil is greater than 5000 ppm, the rate of increase of hydrogen in the oil is greater than 100 ppm / h, or the rate of increase of hydrogen in the gas is greater than 80 ppm / h.

[0015] Furthermore, when the gas accumulation is ≥250mL and the hydrogen content in the gas is >80%, an alarm signal is triggered.

[0016] The present invention adopts the above-mentioned solution, and its beneficial effects are as follows: 1) Through mechanical-electronic dual redundancy protection, the mechanical triggering of the dual floats and electronic monitoring can work in parallel, and the mechanical protection can still operate independently under extreme conditions (such as sensor failure); 2) Through structural optimization, multi-parameter fusion and intelligent algorithm synergy, the accuracy and timeliness of transformer protection are significantly improved, and it is applicable to the safety protection of various oil-immersed power transformers. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a gas relay.

[0018] Figure 2 This is a schematic diagram of the structure of the dual-float mechanical assembly.

[0019] Figure 3 This is a flowchart of the multi-parameter monitoring module.

[0020] Among them, 1-body, 2-multi-parameter monitoring module, 21-liquid level monitoring unit, 22-hydrogen monitoring unit, 3-dual float mechanical assembly, 31-upper float, 32-lower float, 33-oil flow impact baffle. Detailed Implementation

[0021] To facilitate understanding of the present invention, a more complete description of the invention is provided below with reference to the accompanying drawings, which illustrate preferred embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the disclosure of the invention will be more thorough and complete.

[0022] See appendix Figure 1-3As shown, in this embodiment, a multi-parameter active protection gas relay is installed at a high point between the oil conservator and the oil tank to achieve multi-dimensional perception and graded protection of transformer faults. Specifically, it includes a body 1, a dual-float mechanical assembly 3, and a multi-parameter monitoring module 2. Specifically, the gas relay's measurement and control chamber is connected to the transformer oil tank. During normal operation, the chamber is filled with transformer oil (without gas). When a fault occurs inside the transformer (such as partial discharge or overheating), fault gases such as hydrogen and methane are generated. These gases rise through the oil path and accumulate at the top of the measurement and control chamber, causing the oil level inside the chamber to drop—the more gas accumulates, the lower the oil level. Therefore, the dual-float mechanical assembly 3 and the multi-parameter monitoring module 2 work in parallel to perform monitoring and protection functions.

[0023] In this embodiment, the main body 1 is provided with a measurement and control cavity, which is connected to the oil tank and the transformer oil tank through flange interfaces respectively. The dual float mechanical assembly 3 includes an upper float 31 and a lower float 32 arranged vertically. The upper float 31 and the lower float 32 are connected to a preset micro switch through a preset connecting rod. The upper float 31 and the lower float 32 are used to respond to the liquid level information in the measurement and control cavity. This is a mechanical protection function of a traditional gas relay (light gas alarm, heavy gas trip, low oil level trip). Its structural principle is a conventional technical means and will not be described in detail here.

[0024] Furthermore, the upper and lower floats are made of solid stainless steel to avoid malfunctions caused by oil leakage and sinking, thus reducing the false alarm rate.

[0025] In this embodiment, a multi-dimensional monitoring unit is installed on the main body 1 to monitor the liquid level and gas conditions in the measurement and control cavity of the main body 1. Specifically, it includes an active protection module, a liquid level monitoring unit 21, and a hydrogen monitoring unit 22. The liquid level monitoring unit 21 is used to detect and acquire liquid level information in the measurement and control cavity to reflect the amount of gas accumulation. That is, the liquid level monitoring unit 21 infers the gas volume by detecting the height of the gas-liquid interface. Through indirect measurement, it does not need to directly contact the gas (to avoid corrosive gases damaging the sensor). It is suitable for high voltage and strong electromagnetic interference environments by indirectly calculating through changes in oil level. The hydrogen monitoring unit 22 is used to detect and acquire the hydrogen content in the oil and the hydrogen content in the gas in the measurement and control cavity.

[0026] In this embodiment, the liquid level monitoring unit 21 uses a capacitive liquid level sensor (such as model CLS-100), with a probe length of 150mm, which is inserted into the top of the measurement and control cavity. It measures the height of the gas-liquid interface by the difference in dielectric constant between gas and oil. Its range is 0-10% (corresponding to a gas volume of 0-50mL), resolution is 0.1%, linear error is ≤±0.5%FS, and response time is <1s.

[0027] In this embodiment, the hydrogen monitoring unit 22 employs a semiconductor metal thin-film sensor, based on the hydrogen adsorption characteristics of the Pd-Ag alloy thin film (resistance change rate is positively correlated with hydrogen concentration). The specific principle is as follows: Hydrogen detection in oil: The sensor probe is directly immersed in the transformer oil (no liquid-gas separation required). The thin film is heated to 200℃±5℃ (temperature control via Pt100 thermoelectric resistance feedback). Hydrogen molecules penetrate the oil film and are adsorbed by the film, causing a change in resistance, thereby monitoring the hydrogen content in the oil. Hydrogen detection in gas: Gas is introduced into the sensor's gas chamber through a gas guide tube at the top of the chamber, simultaneously detecting the hydrogen concentration in the gas, thereby monitoring the hydrogen content in the gas. Hydrogen monitoring unit 22 detection range: 0-100% (volume fraction, corresponding to 0-10). 5 ppm); Accuracy: ±100ppm (0-10 4 ppm range), ±5%FS (10 4 -10 5 ppm range); response time: <60s (90% response), lifetime ≥10 years (at room temperature).

[0028] In this embodiment, the acquisition terminals of the active protection module are connected to the liquid level monitoring unit 21 and the hydrogen monitoring unit 22, respectively. The control terminal of the active protection module can be connected to the transformer (not shown in the figure). The active protection module performs graded protection actions based on the liquid level information, the hydrogen content in the oil, and the hydrogen content in the gas.

[0029] In this embodiment, the active protection module calculates the hydrogen content in the oil and the hydrogen content in the gas by continuously sampling the hydrogen content in the oil and the hydrogen content in the gas, respectively, based on the hydrogen monitoring unit 22. The active protection module then performs corresponding protection actions based on the hydrogen content in the oil and / or the hydrogen content in the gas.

[0030] Furthermore, in this embodiment, data can be sampled every 60 seconds by the hydrogen monitoring unit 22 (monitoring and acquiring the rate of change of hydrogen in oil and the rate of change of hydrogen in gas), and the hydrogen rise rate (unit: ppm / h) can be calculated by a differential algorithm, specifically: .

[0031] The graded protection action in this embodiment is divided into a warning stage, an alarm stage, and a tripping stage, as detailed below: Warning Phase: When the hydrogen content in the oil exceeds the rated threshold, or the rate of change of hydrogen in the oil exceeds the rated threshold, or the rate of change of hydrogen in the gas exceeds the rated threshold, a warning signal is triggered; that is, when the hydrogen content in the oil is >5000ppm or the rate of increase of hydrogen in the oil is >100ppm / h or the rate of increase of hydrogen in the gas is >80ppm / h, a warning frame is sent through the active protection module, thereby sending a warning signal (such as a flashing red indicator light) to the preset warning devices (backend system, mobile devices, indicator lights, etc.).

[0032] Alarm phase: When the amount of gas accumulated exceeds the rated threshold and the hydrogen content in the gas exceeds the rated threshold, an alarm signal is triggered. Trip phase: When the liquid level information is lower than the preset lower limit of the liquid level, a trip signal is triggered. That is, when the gas accumulation is ≥250mL (light gas threshold) and the hydrogen content in the gas is >80%, an alarm frame is sent through the active protection module, thereby sending an alarm signal (such as the buzzer sounding) to the preset warning devices (display screen, mobile device, indicator light, buzzer, etc.).

[0033] Trip phase: When the liquid level information is lower than the preset lower limit value, a trip signal is triggered. That is, when the liquid level information is less than 1 / 8 of the total liquid level, a trip frame is sent through the active protection module to cut off the power supply to the transformer.

[0034] In this embodiment, a display module is also included, which is installed outside the main body 1 and is used to display the gas accumulation amount, the hydrogen content in the oil, the hydrogen content in the gas, the rate of change of hydrogen in the oil, and the rate of change of hydrogen in the gas. The display module is a display screen connected to the active protection module to display the above-mentioned parameter information, which is more convenient for on-site personnel to view intuitively.

[0035] Furthermore, the dual float mechanical assembly 3 in this embodiment also includes an oil flow impact baffle 33 located in the middle of the measurement and control cavity (a related Hall sensor can be added at its rotating shaft to monitor the deflection angle of the oil flow impact baffle 33), which is used to reflect the oil flow velocity. That is, when the oil flow velocity is >1.0m / s and the baffle deflection angle is ≥15°, the tripping stage is triggered.

[0036] To facilitate understanding, the following explanations are provided in conjunction with specific embodiments.

[0037] Taking a specific relay as an example, its working process is as follows: 1. Installation and initialization: By connecting the main body 1 between the transformer oil tank and the oil conservator, the measurement and control cavity is connected to the transformer oil circuit, thereby making the transformer oil in the measurement and control cavity (without gas).

[0038] 2. Daily monitoring: During normal operation, the control chamber is filled with transformer oil, the dual floats are at a low position, the liquid level sensor probe detects a gas volume of <250mL, and the hydrogen monitoring unit 22 samples the hydrogen content in the oil and the hydrogen content in the gas every 60 seconds. At the same time, the rate of change of hydrogen in the oil and the rate of change of hydrogen in the gas are calculated based on the hydrogen content in the oil and the hydrogen content in the gas.

[0039] 3. Fault Response: 3.1) Partial Discharge Fault: When the hydrogen content rises to 6000ppm (exceeding the warning threshold), the active protection module triggers a warning signal, and the display module flashes the "Hydrogen Exceeds Standard" indicator light; 3.2) Insulation Overheating Fault: When the gas accumulation reaches 280mL (exceeding the alarm threshold) and the hydrogen content in the gas rises to 85%, the active protection module triggers a light gas alarm, and the background system receives the alarm signal; 3.3) Severe Short Circuit Fault: When the oil flow impact velocity reaches 1.2m / s (exceeding the heavy gas threshold) or the liquid level information is lower than 1 / 8 of the total liquid level, the oil flow baffle triggers a trip signal, cutting off the transformer power supply.

[0040] In summary, the gas relay in this embodiment achieves multi-dimensional perception, hierarchical protection, and intelligent early warning of transformer faults through the synergy of mechanical structure and electronic monitoring. It fundamentally addresses the pain points of traditional relays, such as "passive triggering, single parameter, and delayed early warning," especially by employing dual float mechanical and electronic redundancy protection: 1) Mechanical triggering: upper float 31 (triggers light gas alarm when gas ≥ 250mL), lower float 32 (triggers tripping when oil level < 1 / 8), and oil flow baffle (triggers heavy gas tripping when flow velocity > 1.0m / s), operating independently under extreme conditions; 2) Electronic monitoring: synchronously collects hydrogen concentration, oil level, and oil flow velocity in the oil / gas, achieving proactive early warning through an active protection module, thus realizing an active protection mechanism. This upgrades from "tripping after a fault" to "early warning before a fault," and by fusing multiple parameters such as hydrogen rate and gas quantity, it identifies potential faults (such as local overheating and insulation aging) in advance, significantly improving the timeliness and accuracy of transformer protection and providing crucial assurance for the safe operation of power equipment.

[0041] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any modifications or variations made by those skilled in the art, without departing from the scope of the present invention, using the disclosed technical content, are equivalent embodiments of the present invention. Therefore, all equivalent changes made based on the concept of the present invention without departing from the scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A multi-parameter active protection gas relay, characterized in that: It includes a main body (1), a dual-float mechanical assembly (3) located in the measurement and control cavity of the main body (1), and a multi-parameter monitoring module (2) located on the main body (1), wherein, The dual-float mechanical assembly (3) includes an upper float (31) and a lower float (32) arranged vertically, which are used to respond to liquid level information in the measurement and control cavity; The multi-parameter monitoring module (2) includes an active protection module, a liquid level monitoring unit (21), and a hydrogen monitoring unit (22). The liquid level monitoring unit (21) is used to detect and acquire liquid level information in the measurement and control cavity to reflect the amount of gas accumulation. The hydrogen monitoring unit (22) is used to detect and acquire the hydrogen content in the oil and the hydrogen content in the gas in the measurement and control cavity. The active protection module's acquisition terminals are respectively connected to the liquid level monitoring unit (21) and the hydrogen monitoring unit (22), and the active protection module performs graded protection actions based on the liquid level information, the hydrogen content in the oil, and the hydrogen content in the gas.

2. The multi-parameter active protection gas relay according to claim 1, characterized in that: The graded protection action is divided into a warning stage, an alarm stage, and a tripping stage, among which... Warning phase: When the hydrogen content in the oil exceeds the rated threshold, a warning signal is triggered; Alarm phase: When the amount of gas accumulated exceeds the rated threshold and the hydrogen content in the gas exceeds the rated threshold, an alarm signal is triggered. Trip phase: When the liquid level information is lower than the preset lower limit value, a trip signal is triggered.

3. The multi-parameter active protection gas relay according to claim 2, characterized in that: The active protection module calculates the hydrogen content in the oil and the hydrogen content in the gas by continuously sampling the hydrogen content in the oil and the hydrogen content in the gas, respectively, based on the hydrogen monitoring unit (22). The active protection module then performs corresponding protection actions based on the hydrogen content in the oil and / or the hydrogen content in the gas.

4. A multi-parameter active protection gas relay according to claim 3, characterized in that: When the rate of change of hydrogen in oil and / or the rate of change of hydrogen in gas exceeds the rated threshold, a warning signal is triggered.

5. A multi-parameter active protection gas relay according to claim 3, characterized in that: It also includes a display module installed outside the main body (1) for displaying the amount of gas accumulation, the hydrogen content in the oil, the hydrogen content in the gas, the rate of change of hydrogen in the oil, and the rate of change of hydrogen in the gas.

6. A multi-parameter active protection gas relay according to claim 1, characterized in that: The upper floating ball (31) and the lower floating ball (32) are made of solid stainless steel.

7. A multi-parameter active protection gas relay according to claim 2, characterized in that: The dual-float mechanical assembly (3) also includes an oil flow impact baffle (33) located in the middle of the measurement and control cavity, which is used to reflect the oil flow velocity.

8. A multi-parameter active protection gas relay according to claim 7, characterized in that: When the oil flow rate exceeds the rated threshold, the tripping phase is triggered.

9. A multi-parameter active protection gas relay according to claim 4, characterized in that: An early warning signal is triggered when the hydrogen content in the oil is greater than 5000 ppm, the rate of hydrogen rise in the oil is greater than 100 ppm / h, or the rate of hydrogen rise in the gas is greater than 80 ppm / h.

10. A multi-parameter active protection gas relay according to claim 2, characterized in that: An alarm signal is triggered when the gas accumulation is ≥250mL and the hydrogen content in the gas is >80%.

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