Oil chromatography doubling control system and method
By using a dual oil chromatography control system, two sets of oil chromatography monitoring devices are used to sample and integrate the data from different parts of the transformer, which solves the problems of accuracy and stability in monitoring gas in transformer oil and realizes intelligent assessment of transformer condition and operation and maintenance decisions.
Patent Information
- Application Number
- CN202410764761.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-14
- Publication Date
- 2025-12-16
AI Technical Summary
Existing transformer oil chromatography monitoring devices cannot effectively monitor gases in transformer oil, resulting in distorted data and low operational stability. They cannot guarantee the reliability of transformer equipment and the accuracy of monitoring, nor can they comprehensively assess the condition of the transformer.
The system employs a dual-control system based on oil chromatography, which uses two sets of oil chromatography monitoring devices to sample different parts of the transformer, collect differentiated data, and integrate and analyze the signals through the dual-control system to determine the transformer's status and remotely control it. It has self-control, self-inspection, and self-calibration capabilities, and integrates monitoring data and fault alarms.
It improves the accuracy and reliability of gas monitoring in transformer oil, enhances the ability to sense, monitor and warn of transformers, and enables intelligent assessment of transformer status and intelligent operation and maintenance decisions.
Smart Images
Figure CN121141920A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of oil chromatography monitoring and control technology for transformers, specifically an oil chromatography dual control system and method. Background Technology
[0002] As the hub connecting different voltages in the entire power system, the proper operation of transformers determines the safety and stability of the power grid. The safe and stable operation of transformers is an indispensable key factor for power safety and reliability, and effective measures must be taken to prevent and reduce transformer failures.
[0003] Online oil chromatography monitoring devices are currently the most effective means of early warning of abnormalities in large oil-filled equipment. In recent years, multiple transformer failures have occurred in operating UHV substations, which have had a significant impact on the safe and stable operation of the power grid. This also reflects that the ability to perceive, monitor, and warn of the status of large oil-filled equipment cannot meet the actual needs.
[0004] Several technologies exist, some providing a variable threshold-based method for detecting outliers in online oil chromatography monitoring data to address the problem of data distortion in online systems. Others utilize an oil chromatography control unit that adjusts its operating time to regulate the data acquisition interval of the data acquisition module. This interval is adjusted based on comparison results from a comparison and diagnostic output module, which also outputs diagnostic results and transmits them to a backend system via a communication module, thus providing an adaptively adjustable oil chromatography control unit. Still others address multi-mode stratified automatic oil sampling monitoring methods for transformers. Since oil quality at different depths is correlated with faults, this method can link fault conditions with oil samples taken at different depths, enabling the targeted collection of oil samples at specific depths. This provides a multi-mode stratified automatic oil sampling monitoring method for transformers that collects oil samples at designated depths and frequencies based on monitoring data, achieving stratified oil sampling at different depths of the transformer.
[0005] Analyzing the characteristic gas composition and content in transformer insulating oil is crucial for assessing equipment operating status and fault conditions. Currently, transformer oil chromatography monitoring devices are ineffective at monitoring gases in transformer oil, resulting in data distortion, low device stability, and an inability to guarantee the reliability of transformer operation. There is a need to improve the monitoring and early warning capabilities for large transformers, enhance the reliability and accuracy of transformer monitoring, and refine oil chromatography monitoring and analysis strategies. Existing power transformer monitoring solutions cannot comprehensively assess transformers; efficiently and accurately determining the condition of power transformers has become a pain point for on-site operation and maintenance personnel and a challenge for transformer online monitoring manufacturers. Summary of the Invention
[0006] To achieve the above objectives, this invention proposes a dual-configuration control system and method for oil chromatography. The dual-configuration control system includes a dual-configuration online oil chromatography monitoring device and a dual-configuration control device. The dual-configuration oil chromatography monitoring device collects oil samples from multiple points on a large transformer, gathering differentiated data from different parts of the transformer. The dual-configuration control device establishes communication with the oil chromatography monitoring device via the DL / T 860 communication protocol. The dual-configuration control device collects real-time data from two on-site installed online oil chromatography monitoring devices, integrates and analyzes the signals, and performs monitoring deployment as required. Based on the online oil chromatography monitoring data, the transformer status is determined, remote control is implemented, and mechanisms for resampling, shortening the cycle time, and data comparison are activated. Logical analysis is performed on the data from the two oil chromatography devices, and the corresponding device control strategy is determined based on the analysis results.
[0007] The dual-control oil chromatography system can comprehensively reflect the operating status of large transformer oil chromatographs, perform comprehensive diagnosis of gases in transformer oil, and send monitoring data and fault alarms to the backend. The transformer oil gas monitoring system is the core of the dual-control oil chromatography system, possessing the capabilities of transformer self-control, self-inspection, self-testing, and self-calibration, realizing the perception of the operating status of power equipment, intelligent judgment of defects and anomalies, intelligent control of operating conditions, and intelligent decision-making for operation and maintenance.
[0008] The technical solution adopted by the present invention to achieve the above objectives is as follows:
[0009] A dual-control system for oil chromatography includes two sets of oil chromatography monitoring devices and one oil chromatography control device. The two sets of oil chromatography monitoring devices share a common oil return port, and the two sets of monitoring devices are respectively connected to different oil inlets of the transformer. The oil chromatography control device is located in the substation monitoring room and is connected to the monitoring devices via a communication cable.
[0010] The oil chromatography control device includes:
[0011] The protocol acquires arbitration data to obtain real-time oil chromatography data and sends configuration and control data to the oil chromatography monitoring device.
[0012] The general data processing terminal is used to process real-time oil chromatography data and store the processed data in a local relational database.
[0013] The data display terminal is used to show transformer oil chromatographic monitoring data and modified configuration data.
[0014] The protocol collects data from the arbitration panel, including:
[0015] The data acquisition and analysis module is used to acquire real-time oil chromatographic data from the oil chromatographic monitoring device and to send control data and configuration data to it.
[0016] The first data processing module is used to interact with the acquisition and parsing module and the data arbitration module respectively, and to interact with the general data processing terminal through shared memory.
[0017] The data arbitration module is used to perform logical analysis and judgment on the received real-time oil chromatography data through the arbitration logic configuration information in the arbitration configuration file, and generate and send control data.
[0018] The general data processing terminal includes:
[0019] The second data processing module is used to filter and select the shared data in memory;
[0020] The data storage module is used to store the processed data into a local relational database.
[0021] The data display terminal includes:
[0022] The data display module is used to display real-time and historical data from the two sets of oil chromatography monitoring for the transformer.
[0023] The data configuration module is used to modify configuration data and synchronize it to the local relational database.
[0024] The specific arrangement of the oil inlet and outlet ports corresponding to the two sets of oil chromatography monitoring devices on the transformer is as follows:
[0025] If the transformer has a dedicated oil inlet or outlet for the online monitoring device for dissolved gases in oil, and the oil inlet of the transformer is arranged diagonally relative to the oil inlet of the transformer, then the oil chromatography monitoring devices A and B shall select the oil inlets at the lower and upper parts of the transformer as oil inlet 1 and oil inlet 2, respectively.
[0026] If there is no dedicated oil inlet or outlet for the online dissolved gas monitoring device on the transformer, and if an oil chromatography monitoring device A has been installed on the transformer, then the original oil inlet position of the on-site oil chromatography monitoring device A shall remain unchanged and shall be used as inlet 1. If the on-site transformer has not installed oil chromatography monitoring device A, then the oil inlet of oil chromatography monitoring device A shall be selected on the oil collection pipeline of the cooling device at the bottom of the transformer as inlet 1. The oil inlet of oil chromatography monitoring device B shall be installed on the pipeline at the active oil flow position outside the transformer, opposite to the oil inlet of oil chromatography monitoring device A, as inlet 2, and shall be arranged diagonally to inlet 1.
[0027] The oil inlet in the middle of the transformer is selected as the oil return port, and the oil return of the dual distribution device is realized by adding a three-way valve.
[0028] A dual-control method for oil chromatography includes the following steps:
[0029] When the real-time oil chromatography data collected by the oil chromatography monitoring device is normal, the oil chromatography control device controls both oil chromatography monitoring devices to sample at a period of N hours. The sampling interval between the two oil chromatography monitoring devices is N / 2 hours. That is, if oil chromatography monitoring device A is set to start at time T, then oil chromatography monitoring device B needs to start at time T+(N / 2)h.
[0030] When the real-time oil chromatographic data collected by any oil chromatographic monitoring device exceeds the set threshold, an alarm signal is sent, and both sets of oil chromatographic monitoring devices automatically start testing and simultaneously start collecting oil samples, and the monitoring cycle is shortened to N / 2 hours.
[0031] When the monitoring results from the two oil chromatography monitoring devices differ, the oil chromatography control device performs the following processing:
[0032] If the data monitored by both oil chromatography monitoring devices are normal, then a second simultaneous monitoring will be performed. If the result is still normal, then the device is determined to be a false alarm, and the normal N-hour monitoring cycle will be restored. The sampling interval between the two oil chromatography devices is N / 2 hours.
[0033] If two oil chromatography monitoring devices produce different results when monitoring simultaneously, and the outlier device is consistent with the previous outlier monitoring device, continue to wait for the second simultaneous monitoring result or manually verify it to rule out the possibility of false alarms from the device.
[0034] If the monitoring results of both oil chromatography monitoring devices are abnormal, the oil chromatography control device will control the oil chromatography monitoring devices to continue a second simultaneous monitoring. If the results are still abnormal, the equipment status of the transformer will be further evaluated manually.
[0035] The present invention has the following beneficial effects and advantages:
[0036] 1. This invention provides a dual-control system and method for oil chromatography. The dual-control device collects data from two online oil chromatography monitoring devices, performs comparative analysis and logical judgment, evaluates the real-time operating status of the transformer based on the dual-monitoring data, optimizes the monitoring data anomaly algorithm, and effectively improves the accuracy of gas monitoring in the oil of large transformers.
[0037] 2. This invention realizes the control of the sampling cycle and sampling time of the dual-mode oil chromatography monitoring device through a dual-mode control device, which flexibly adjusts the sampling cycle and sampling time according to the oil chromatography monitoring results. When the monitoring data is abnormal, the sampling cycle is adjusted according to the analysis results, which improves the intelligence of the monitoring and provides a control device that can automatically adjust the working cycle of the oil chromatography device.
[0038] 3. This invention enables threshold setting control of a dual-control oil chromatography monitoring device through a dual control mechanism. Maintenance administrators can modify the warning and alarm thresholds for oil chromatography monitoring data such as hydrogen, methane, acetylene, ethylene, ethane, carbon monoxide, carbon dioxide, and total hydrocarbons. Oil chromatography monitoring data is susceptible to influences from environmental temperature, humidity, and inherent equipment errors. Therefore, anomaly detection and correction are necessary before analysis and diagnosis. This invention allows for flexible adjustment of the warning thresholds of the oil chromatography monitoring device, enhancing the device's sensing, monitoring, and early warning capabilities for transformers.
[0039] 4. By diagonally arranging the oil sampling ports of the dual-oil chromatography monitoring device, the oil sampling ports are set at the active oil flow positions in the transformer tank, enabling multi-point, all-round monitoring of the transformer body. The configuration and layout follow the principle that the oil sampling ports are representative and that the two oil sampling ports are located on different sides of the main transformer tank (with the relative distance as far as possible). The dual-oil chromatography control device can collect the differentiated monitoring data of the two oil chromatography devices in real time, view the real-time data and historical data of gas in the transformer oil, and reliably grasp the overall operating status of the large transformer.
[0040] 5. Real-time setpoints for the sampling cycle, gas alarm value, and sampling time of the oil chromatography device can be obtained through the dual control device for oil chromatography, enabling remote control of the oil chromatography monitoring device, such as setting modification and immediate sampling. Attached Figure Description
[0041] Figure 1 Structure diagram of the dual-control system for oil chromatography;
[0042] Figure 2 Overall framework diagram of the transformer oil gas monitoring system of the oil chromatography dual control device;
[0043] Figure 3 Data flow diagram of oil chromatography monitoring device and oil chromatography dual control device;
[0044] Figure 4 Alarm handling flowchart for oil chromatography dual-control device. Detailed Implementation
[0045] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0046] like Figure 1 As shown, the overall layout of the dual-mode oil chromatography online monitoring device should follow the principle that the oil sampling points are representative and that the two sampling points are located on different sides of the main transformer tank (with the greatest possible relative distance). The sampling point location should reflect the overall operating status of the transformer. Given that there are many defects in the bushing riser and outgoing line devices of transformers with voltage levels of 500 kV and above, the monitoring of oil samples in the middle and upper parts of the transformer body should be strengthened when using a dual-mode configuration.
[0047] This plan defines the existing online oil chromatography monitoring device of the main transformer as Device A, and the newly added online oil chromatography monitoring device as Device B. Based on the common types of 500 kV transformers, and depending on whether the transformer body has a dedicated oil inlet / outlet port, two typical layout schemes are proposed:
[0048] 1. The main transformer body has a dedicated oil inlet / outlet: For the main transformer body with a dedicated oil inlet / outlet for the dissolved gas in oil online monitoring device, and the oil inlet of the device is located diagonally opposite to the oil inlet of the main transformer body, the oil inlets of devices A and B are selected at the lower and upper parts of the main body, respectively, as the oil inlets of the device, and the oil inlet in the middle of the main body is selected as the oil return port of the device. The oil return of the dual distribution device is realized by adding a three-way valve. No hole modification is required, which can increase the number of sampling points and increase the sampling frequency.
[0049] 2. The main transformer body lacks a dedicated oil inlet / outlet: If the main transformer body lacks a dedicated online oil dissolved gas monitoring device for oil inlet / outlet, and an oil chromatograph A is already installed on the site, maintain the original oil inlet position of the on-site oil chromatograph A as inlet 1. If the on-site transformer does not have an oil chromatograph, the oil inlet (inlet 1) of oil chromatograph A should be selected on the oil collection pipeline of the transformer cooling device (lower part). The oil inlet of device B should be added to the opposite side of the transformer from the oil inlet of oil chromatograph A, utilizing external pipelines in areas with active oil flow, such as oil pipes connected to the radiator, to increase the number of sampling points and improve sampling frequency. The oil inlets should be located in the active oil flow area of the transformer body and arranged diagonally to achieve multi-point, all-round monitoring of the transformer body. It is recommended to select the oil inlet on the oil collection pipeline of the transformer cooling device (lower part).
[0050] like Figure 2 As shown, the transformer oil gas monitoring system platform of this patented dual-control oil chromatography device includes: a protocol acquisition and arbitration terminal, a general data processing terminal, and a data display terminal. The protocol acquisition and arbitration terminal consists of an acquisition and parsing module, a data processing module, and a data arbitration module; the general data processing terminal consists of a data processing module and a data storage module; and the data display terminal consists of a data display module and a data configuration module.
[0051] The protocol acquisition and arbitration end consists of an acquisition and parsing module, a data processing module, and a data arbitration module. The acquisition and parsing module configures the real-time oil chromatography data, configuration data, and control data to be acquired through an acquisition configuration file. It establishes a TCP connection with the dual oil chromatography systems using the DL / T 860 communication protocol and an RJ45-compliant communication cable, enabling bidirectional communication. This allows for simultaneous real-time oil chromatography data acquisition while simultaneously modifying the acquisition cycle and issuing control data to immediately initiate sampling. The acquisition and parsing module interacts with the data processing module to exchange real-time, configuration, and control data. The data processing module interacts with the data arbitration module. The data arbitration module, based on the arbitration logic configuration information in the arbitration configuration file, performs logical analysis and judgment on the received real-time oil chromatography data, issuing corresponding control data such as resampling, threshold setting, and cycle setting, thereby achieving the purpose of monitoring and controlling the dual oil chromatography systems.
[0052] The data processing module at the arbitration end and the data processing module at the general data processing end interact with each other for real-time and control data via a shared data address in memory. The data processing module at the general data processing end filters and selects the shared data in memory before storing it in the data storage module. The data storage module at the general data processing end then stores the processed data in the local relational database of the monitoring system.
[0053] The data display terminal uses a browser / server model to provide users with data browsing and remote control functions. After the user opens a browser and enters the monitoring system's IP address and port number, the data display terminal accesses the local relational database to obtain real-time data from the oil chromatography and transmits it to the user's browser. The user can view the transformer's real-time and historical data through the browser; the user can modify the oil chromatography device's sampling period, threshold, and start-up operation configuration information through the data configuration module, which synchronously updates the modified content to the local relational database. After receiving the database update information, the general data processing terminal's data processing module sends the modified configuration data to the oil chromatography device via DL / T 860 communication by sharing data addresses in memory. The oil chromatography device then updates the corresponding sampling period and threshold. If there is control data such as starting sampling, the oil chromatography device immediately executes the corresponding control command.
[0054] like Figure 3As shown, the oil chromatography unit and the oil chromatography dual control unit exchange operational data. The oil chromatography dual control unit communicates with the oil chromatography monitoring unit via the DL / T 860 communication protocol. The oil chromatography dual control unit collects real-time data from both oil chromatography monitoring units, receives remote signaling and telemetry data from the oil chromatography units, performs remote control, activates corresponding mechanisms, performs logical analysis on different data, determines corresponding handling strategies based on real-time data, and controls the sampling cycle, sampling time, alarm thresholds, etc., of the oil chromatography monitoring units, thereby realizing remote control and adjustment of the oil chromatography monitoring units. Communication is transmitted in the form of MMS messages. Real-time monitoring data flows unidirectionally from the online oil chromatography monitoring unit to the oil chromatography dual control unit, while non-real-time remote control data flows unidirectionally from the oil chromatography dual control unit to the online oil chromatography monitoring unit.
[0055] The transformer oil gas monitoring system with dual control of oil chromatography comprises three layers: the sensing layer, the field layer, and the monitoring layer. 1. Sensing Layer: This layer acquires data from the online transformer oil chromatography monitoring device, collects status data of gases in the transformer oil, and serves as a data import point for offline data such as transformer factory maintenance and repair data. 2. Field Layer: Centered on the oil chromatography monitoring host, this layer enables automatic and remote control functions such as the oil chromatography data acquisition cycle, as well as edge computing and IoT communication for status assessment, fault diagnosis, and data transmission. 3. Monitoring Layer: This layer displays and queries monitoring data from the transformer equipment via a web interface and allows for data and control command interaction with the substation control layer.
[0056] The dual-control oil chromatography system collects oil chromatographic data and analyzes and diagnoses the transformer oil chromatographic data using methods such as the David's triangle method, the three-ratio method, and the lexical diagram method. Furthermore, it can be extended to include advanced transformer condition analysis applications such as DGA trend prediction, fault diagnosis, and remaining insulation life prediction, using neural network deep learning algorithms and data collected from the monitoring layer.
[0057] like Figure 4 The control steps and methods of the oil chromatography dual-control device are shown below:
[0058] (1) Under normal circumstances, the dual-control oil chromatography system controls the oil chromatography to operate in the conventional mode. The dual-control system is configured with two sets of oil chromatography devices, each sampling with a 4-hour cycle. The sampling interval between the two sets of oil chromatography devices is 2 hours, thus achieving a 2-hour sampling cycle. A total of 12 sets of online monitoring data of oil chromatography are obtained per day. Taking the dual-configuration oil chromatography devices A and B as an example, if oil chromatography device A is set to start at time T, then oil chromatography device B needs to be started at time (T+2h).
[0059] (2) In case of abnormality, if the monitoring data of any one of the dual-configuration oil chromatography devices exceeds the set threshold, an alarm signal will be sent to the background, the dual oil chromatography devices will automatically start testing, and oil samples will be collected at the same time, and the monitoring cycle will be shortened to two hours.
[0060] Based on the different monitoring results of the dual-configuration oil chromatography apparatus, the dual-configuration control apparatus for oil chromatography can be categorized into the following treatment methods:
[0061] (1) If the data monitored by the dual-configuration oil chromatography device are all normal, then continue to perform the second simultaneous monitoring. If the result is still normal, then the device is determined to be a false alarm and the normal 4-hour monitoring cycle is restored. The sampling interval between the two oil chromatography devices is 2 hours.
[0062] (2) If different results are obtained when the dual-configuration oil chromatography device is used for simultaneous monitoring, and the abnormal value device is consistent with the previous abnormal value monitoring device, you can continue to wait for the second simultaneous monitoring result or manually check to rule out the possibility of false alarms from the device.
[0063] (3) If the monitoring results of the dual-configuration oil chromatography device are all abnormal, the dual-configuration control device controls the oil chromatography to continue the second simultaneous monitoring. If the results are still abnormal, experts will be organized to discuss and further evaluate the equipment status of the transformer.
Claims
1. A dual-control system for oil chromatography, characterized in that, It includes two sets of oil chromatography monitoring devices and one oil chromatography control device. The two sets of oil chromatography monitoring devices share a common oil return port. The two sets of monitoring devices are respectively connected to different oil intake ports of the transformer. The oil chromatography control device is located in the substation monitoring room and is connected to the monitoring devices through a communication cable.
2. The oil chromatography dualization control system according to claim 1, characterized in that, The oil chromatography control device includes: The protocol acquires arbitration data to obtain real-time oil chromatography data and sends configuration and control data to the oil chromatography monitoring device. The general data processing terminal is used to process real-time oil chromatography data and store the processed data in a local relational database. The data display terminal is used to show transformer oil chromatographic monitoring data and modified configuration data.
3. The dual-control system for oil chromatography according to claim 2, characterized in that, The protocol collects data from the arbitration panel, including: The data acquisition and analysis module is used to acquire real-time oil chromatographic data from the oil chromatographic monitoring device and to send control data and configuration data to it. The first data processing module is used to interact with the acquisition and parsing module and the data arbitration module respectively, and to interact with the general data processing terminal through shared memory. The data arbitration module is used to perform logical analysis and judgment on the received real-time oil chromatography data through the arbitration logic configuration information in the arbitration configuration file, and generate and send control data.
4. The dual-control system for oil chromatography according to claim 2, characterized in that, The general data processing terminal includes: The second data processing module is used to filter and select the shared data in memory; The data storage module is used to store the processed data into a local relational database.
5. The oil chromatography dualization control system according to claim 2, characterized in that, The data display terminal includes: The data display module is used to display real-time and historical data from the two sets of oil chromatography monitoring for the transformer; the data configuration module is used to modify the configuration data and synchronize it to the local relational database.
6. The oil chromatography dualization control system according to claim 1, characterized in that, The specific arrangement of the oil inlet and outlet ports corresponding to the two sets of oil chromatography monitoring devices on the transformer is as follows: If the transformer has a dedicated oil inlet or outlet for the online monitoring device for dissolved gases in oil, and the oil inlet of the transformer is arranged diagonally relative to the oil inlet of the transformer, then the oil chromatography monitoring devices A and B shall select the oil inlets at the lower and upper parts of the transformer as oil inlet 1 and oil inlet 2, respectively. If there is no dedicated oil inlet or outlet for the online dissolved gas monitoring device on the transformer, and if an oil chromatography monitoring device A has been installed on the transformer, then the original oil inlet position of the on-site oil chromatography monitoring device A shall remain unchanged and shall be used as inlet 1. If the on-site transformer has not installed oil chromatography monitoring device A, then the oil inlet of oil chromatography monitoring device A shall be selected on the oil collection pipeline of the cooling device at the bottom of the transformer as inlet 1. The oil inlet of oil chromatography monitoring device B shall be installed on the pipeline at the active oil flow position outside the transformer, opposite to the oil inlet of oil chromatography monitoring device A, as inlet 2, and shall be arranged diagonally to inlet 1. The oil inlet in the middle of the transformer is selected as the oil return port, and the oil return of the dual distribution device is realized by adding a three-way valve.
7. A dual-control method for oil chromatography, characterized in that, Includes the following steps: When the real-time oil chromatography data collected by the oil chromatography monitoring device is normal, the oil chromatography control device controls both oil chromatography monitoring devices to sample at a period of N hours. The sampling interval between the two oil chromatography monitoring devices is N / 2 hours. That is, if oil chromatography monitoring device A is set to start at time T, then oil chromatography monitoring device B needs to start at time T+(N / 2)h. When the real-time oil chromatographic data collected by any oil chromatographic monitoring device exceeds the set threshold, an alarm signal is sent, and both sets of oil chromatographic monitoring devices automatically start testing and simultaneously start collecting oil samples, and the monitoring cycle is shortened to N / 2 hours.
8. The dual-control method for oil chromatography according to claim 7, characterized in that, When the monitoring results from the two oil chromatography monitoring devices differ, the oil chromatography control device performs the following processing: If the data monitored by both oil chromatography monitoring devices are normal, then a second simultaneous monitoring will be performed. If the result is still normal, then the device is determined to be a false alarm, and the normal N-hour monitoring cycle will be restored. The sampling interval between the two oil chromatography devices is N / 2 hours. If two oil chromatography monitoring devices produce different results when monitoring simultaneously, and the outlier device is consistent with the previous outlier monitoring device, continue to wait for the second simultaneous monitoring result or manually verify it to rule out the possibility of false alarms from the device. If the monitoring results of both oil chromatography monitoring devices are abnormal, the oil chromatography control device will control the oil chromatography monitoring devices to continue a second simultaneous monitoring. If the results are still abnormal, the equipment status of the transformer will be further evaluated manually.