Combustible gas on-line monitoring system for transformer gas relay

Abstract

The utility model discloses a combustible gas on-line monitoring system for a transformer gas relay. The combustible gas on-line monitoring system comprises an oil-gas separation module, a detection module, a control module and a communication module, the oil-gas separation module and the communication module are respectively connected with the control module; the oil-gas separation module and the communication module are respectively connected with the detection module, and the oil-gas separation module is used for separating gas in an oil-gas mixture; the detection module is used for detecting components and concentration of gas; the control module regulates and controls the oil-gas separation module according to the obtained fault signal sent by the gas relay; and the communication module is used for transmitting the gas detection result to a master control room or a remote monitoring center. By adopting the technical scheme of the utility model, the real-time monitoring of combustible gases-hydrogen and methane in the transformer gas relay is realized.

Description

Technical Field

[0001] This utility model belongs to the field of transformer technology, and in particular relates to an online monitoring system for combustible gases used in transformer gas relays. Background Technology

[0002] During the long and continuous operation of a transformer, various factors such as electrical stress, thermal stress, and mechanical stress can cause chemical changes in the insulating oil, leading to the release of various flammable gases, such as hydrogen (H2) and methane (CH4), from the transformer's gas relay. The content and trends of these gases are key indicators for determining whether there are faults inside the transformer and the severity of those faults. In particular, the presence of hydrogen and methane usually indicates potential abnormalities such as overheating, arcing, or partial discharge inside the transformer.

[0003] Among traditional methods for analyzing gases evolved from transformer gas relay oil, chromatography (GC) is the most commonly used. However, GC has a complex implementation process, including sample pretreatment, instrument parameter optimization, and data analysis. These steps not only increase the technical barrier to entry but also extend the overall analysis cycle. Therefore, traditional methods for detecting gases evolved from transformer gas relay oil suffer from operational complexity and high costs. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide an online monitoring system for combustible gases for transformer gas relays.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An online combustible gas monitoring system for a transformer gas relay includes: an oil-gas separation module, a detection module, a control module, and a communication module; the oil-gas separation module and the communication module are respectively connected to the control module; the oil-gas separation module and the communication module are respectively connected to the detection module, wherein the oil-gas separation module is used to separate the gas from the oil-gas mixture; the detection module is used to detect the composition and concentration of the gas; the control module adjusts the oil-gas separation module according to the fault signal issued by the gas relay; and the communication module is used to transmit the gas detection results to the main control room or a remote monitoring center.

[0007] Preferably, the oil-gas separation device includes: a gas collecting tank, on which an inlet / oil solenoid valve is provided to regulate the inlet and outlet of gas, thereby realizing gas extraction and separation during the automatic gas collection process; a float-type liquid level sensor is provided on the cover of the gas collecting tank to monitor changes in the oil level in real time; and a waste oil solenoid valve is provided at the bottom of the gas collecting tank to discharge the separated oil.

[0008] Preferably, the detection module includes a methane sensor and a hydrogen sensor, which are encapsulated in a sensor box.

[0009] As a preferred option, the control module uses a Siemens programmable logic controller (PLC) as the main control element.

[0010] Preferably, the control module also includes an alarm unit, which automatically triggers a light gas alarm signal when the detected methane and hydrogen concentrations exceed a preset safety threshold.

[0011] Preferably, the communication module includes: an RS485 communication module and a 4-20mA analog input / output module.

[0012] This utility model integrates an oil-gas separation module, a detection module, a control module, and a communication module to achieve real-time monitoring of combustible gases—hydrogen and methane—inside the transformer's gas relay. It can accurately measure the concentration of specific gas components inside the transformer in real time, transmit data instantly, and store it efficiently. It can quickly and accurately assess the health status of the transformer, helping maintenance personnel make judgments and prevent further escalation of accidents. At the same time, it eliminates the need for traditional manual gas sampling and operation, effectively ensuring the personal safety of personnel. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0014] Figure 1 This is a diagram of the combustible gas online monitoring system for transformer gas relays according to this utility model;

[0015] Figure 2 This is a schematic diagram of the oil-gas separation module;

[0016] Figure 3 This is a flowchart of a transformer gas relay combustible gas online monitoring system; where (a) is a switch input, (b) is a digital input, and (c) is an analog input. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Example 1:

[0020] like Figure 1 As shown, this utility model provides an online combustible gas monitoring system for a transformer gas relay, comprising: an oil-gas separation module, a detection module, a control module, and a communication module; the oil-gas separation module and the communication module are respectively connected to the control module; the oil-gas separation module and the communication module are respectively connected to the detection module.

[0021] The oil-gas separation module employs gas separation technology to separate the gas from the oil-gas mixture, while ensuring that the separated oil flows smoothly into the waste oil box. The detection module accurately detects the composition and concentration of the gas, ensuring data accuracy. The control module coordinates the collaborative work between the various modules, ensuring the smooth operation of the entire monitoring process. Simultaneously, the communication module transmits monitoring data to the main control room or remote monitoring center in real time and accurately.

[0022] When the gas relay level reaches the user-preset alarm threshold, the system immediately activates the oil-gas separation module to rapidly separate the gas and then analyze its components and concentration. Once the analysis is complete, the gas concentration data and alarm signal are uploaded in real time to the HMI or remote monitoring center via 4-20mA or RS485 communication protocol. In addition, the system has a cumulative gas sampling volume function. When the cumulative gas sampling volume reaches the user-set light gas alarm value, the equipment automatically triggers an alarm signal to remind maintenance personnel to take timely measures.

[0023] As one embodiment of this utility model, oil-gas separation relies on the significant differences in physical properties between oil and gas, particularly their density and pressure response. During automatic gas extraction, the positive pressure inside the transformer pushes the gas out through a specific outlet, while the negative pressure generated by the oil draining operation guides the gas-containing oil mixture to the gas collecting device. This process combines the effects of positive and negative pressure, ensuring that gas can be efficiently and continuously extracted into the gas collecting device, while the oil is effectively separated in subsequent steps through a precise control mechanism, achieving accurate oil-gas separation and providing a clean gas sample for the subsequent detection module.

[0024] The oil-gas separator uses a stainless steel gas collecting tank as its core component, ensuring the tank's durability and corrosion resistance. Figure 2 As shown, an inlet / oil solenoid valve is integrated on the top of the gas collecting tank for precise control of gas intake and output, enabling gas extraction and separation during the automatic gas collection process. Simultaneously, a float-type liquid level sensor is installed on the gas collecting tank cover to monitor changes in the oil level in real time, providing control signals for the automatic gas collection process. Furthermore, a waste oil solenoid valve is located at the bottom of the gas collecting tank for discharging the separated oil. These components, precisely secured with screws, together constitute the oil-gas separation module.

[0025] In one embodiment of this utility model, methane detection relies on NDIR (Noise Reduction Interference). The core principle of NDIR is that when infrared light passes through the gas to be detected, specific gas molecules absorb infrared light with wavelengths matching their absorption wavelengths; this absorption relationship follows the Lambert-Beer absorption law. To detect methane in a mixture of gases, a narrow-band filter is installed in front of the detection module or infrared light source. This filter filters out the specific wavelengths absorbed by methane molecules. In this way, the detection module can accurately reflect changes in the concentration of the methane gas being measured based on signal changes, thereby effectively analyzing the methane component in the gas mixture. Furthermore, the NDIR detection method is not limited by oxygen concentration, and the built-in temperature probe can perform temperature compensation, ensuring the accuracy of the measurement results.

[0026] Hydrogen detection employs an electrochemical principle. The ECS (Electrochemical Current Detector) works based on an electrochemical reaction, its core structure consisting of an anode, a cathode, and a thin layer of electrolyte between them. When hydrogen molecules permeate through this electrolyte, they come into contact with active substances in the electrolyte, triggering a reversible chemical reaction. This reaction generates a current signal, the intensity of which is directly proportional to the hydrogen concentration. The hydrogen concentration can be accurately calculated based on the detected current magnitude.

[0027] Therefore, a high-precision detection module integrating methane and hydrogen detection functions is designed, comprising two sensors: a methane sensor (NDIR) and a hydrogen sensor (ECS). These two sensors are encapsulated within a compact sensor housing.

[0028] In one embodiment of this utility model, the control module uses a Siemens programmable logic controller (PLC) as the main control element and integrates a human-machine interface (HMI) touchscreen. To ensure the stable operation of the PLC in complex electromagnetic environments, intermediate relays are equipped in the control module to effectively isolate external electromagnetic interference.

[0029] The PLC receives various signal inputs in real time, including switch signals, analog signals, and digital signals. These signals reflect parameters such as oil level and gas concentration monitoring parameters of the gas relay. To ensure data accuracy and reliability, the PLC incorporates multiple filtering algorithms, such as amplitude limiting filtering, mean filtering, and integral processing algorithms, to finely process the received analog signals and effectively eliminate interference. Parameter configurations for the analog input channels are also optimized, including settings for sampling frequency and dead-zone threshold, further improving signal accuracy. Based on the processed signal data, the PLC intelligently determines whether adjustments to the oil-gas separation module and the detection module are necessary. If adjustments are required, the PLC quickly controls the on / off state of the solenoid valves to regulate these two modules.

[0030] The HMI (Hardware Management System) serves as a platform for operator interaction with the system, providing detailed information display and convenient operation and control functions. Through the HMI, operators can intuitively monitor key information such as gas relay oil levels, gas detection results, historical alarm records, and current equipment status, facilitating system monitoring and management. Furthermore, the HMI integrates a user login function, effectively preventing unauthorized operations and ensuring system security through a strict access control mechanism. After successful login, users can manually operate solenoid valve switches on the display screen, achieving flexible system control.

[0031] To ensure the overall safety and stability of the system, the control module also includes an alarm unit, which monitors and diagnoses out-of-limit situations in module data in real time, promptly identifying and addressing potential problems. Simultaneously, the integrated short-circuit alarm function can quickly trigger an alarm in the event of an anomaly, preventing module damage.

[0032] In one embodiment of this utility model, the communication module integrates an RS485 communication module and a 4-20mA analog input / output module to achieve remote monitoring and management functions of the system. The RS485 communication module provides a high-speed, reliable data transmission channel, enabling the PLC to exchange data and transmit commands in real time with the remote monitoring center. The 4-20mA analog input / output module is used for remote communication with the smart substation terminal. This module can receive and process analog signals from the substation terminal in real time, such as the component concentration data of combustible gases (H2 and CH4) in the transformer gas relay, and light gas alarm signals.

[0033] As one embodiment of this utility model, the working process of the online combustible gas monitoring system of this utility model is as follows:

[0034] The PLC receives various types of fault signals, including switching signals, analog signals, and digital signals from the transformer gas relay, such as... Figure 3 As shown. The signal transmission mechanism varies depending on its type: switch signals are directly connected to the PLC for instant response; digital signals are transmitted using an RS485 communication module; analog signals require conversion and preprocessing via a 4-20mA analog input / output module to meet the PLC's input requirements.

[0035] When the PLC receives a fault signal from the gas relay, it automatically triggers and executes a series of control commands based on preset logic algorithms and program flows. Specifically, the PLC sends a control signal to the air / oil solenoid valve, instructing it to open, thereby allowing the oil-gas mixture inside the transformer to flow into the gas collecting tank along a preset path. Inside the gas collecting tank, based on the density difference between oil and gas, the oil naturally settles to the bottom, while the gas rises to the top and accumulates. As the oil level inside the gas collecting tank continues to rise, the internal gas is gradually compressed under the positive pressure effect and released into the detection module.

[0036] The sensors embedded in the detection module first measure the concentrations of methane and hydrogen, converting this information into current signals. Subsequently, a 4-20mA analog input / output module receives these current signals and performs signal conversion processing, transforming them into digital signals recognizable by the PLC. The PLC receives these digital signals, analyzes them, and displays the methane and hydrogen concentration detection results on the HMI (Human-Machine Interface). Simultaneously, the system also features real-time upload capabilities, transmitting gas concentration data and potential alarm signals to the HMI or a remote monitoring center via 4-20mA or RS485 communication protocols. Furthermore, the PLC possesses intelligent monitoring and judgment functions; if the detected methane and hydrogen concentrations exceed preset safety thresholds, the PLC automatically triggers a light gas alarm signal to ensure the safe operation of the system.

[0037] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Any modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A combustible gas online monitoring system for a transformer gas relay, characterized in that, include: Oil-gas separation module, detection module, control module, and communication module; The oil-gas separation module and the communication module are respectively connected to the control module; The oil-gas separation module and the communication module are respectively connected to the detection module. The oil-gas separation module is used to separate the gas from the oil-gas mixture; the detection module is used to detect the composition and concentration of the gas; the control module adjusts the oil-gas separation module according to the fault signal issued by the gas relay; and the communication module is used to transmit the gas detection results to the main control room or remote monitoring center.

2. The combustible gas online monitoring system for transformer gas relays as described in claim 1, characterized in that, The oil-gas separation device includes: a gas collection tank, on which an inlet / oil solenoid valve is installed to regulate the inlet and outlet of gas, thereby realizing gas extraction and separation during the automatic gas collection process; a float-type liquid level sensor is installed on the cover of the gas collection tank to monitor changes in the oil level in real time; and a waste oil solenoid valve is installed at the bottom of the gas collection tank to discharge the separated oil.

3. The combustible gas online monitoring system for transformer gas relays as described in claim 1, characterized in that, The detection module includes a methane sensor and a hydrogen sensor, which are encapsulated in a sensor box.

4. The combustible gas online monitoring system for transformer gas relays as described in claim 3, characterized in that, The control module uses a Siemens programmable logic controller (PLC) as the main control element.

5. The combustible gas online monitoring system for transformer gas relays as described in claim 4, characterized in that, The control module also includes an alarm unit, which automatically triggers a light gas alarm signal when the detected methane and hydrogen concentrations exceed preset safety thresholds.

6. The combustible gas online monitoring system for transformer gas relays as described in claim 5, characterized in that, The communication module includes: an RS485 communication module and a 4-20mA analog input / output module.

Images