An online charged filter leakage detection system and detection method

Abstract

This invention discloses an online live-line oil filtration machine leakage detection system and method, relating to the field of power equipment monitoring technology. The system includes an inlet pipe leakage detection unit, an outlet pipe leakage detection unit, a main unit internal leakage detection unit, a cumulative flow difference judgment unit, and a control and alarm unit. The inlet and outlet pipe units detect leaks by comparing flow rates at both ends of the pipes using flow meters; the main unit internal unit detects internal leaks by detecting the liquid level at the lowest point of the machine; the cumulative flow judgment unit determines whether the transformer has an abnormal oil shortage risk by periodically comparing the cumulative flow difference between the transformer's outlet and inlet sides. When any of the above units detects an abnormality, the control and alarm unit can interlock and control the oil filtration machine to stop operation and cut off the inlet and outlet oil passages, while simultaneously issuing an alarm. This invention effectively improves the safety and reliability of the online live-line oil filtration process.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment monitoring, and particularly relates to an on-line live oil filter leakage detection system and a detection method. Background Art

[0002] During the operation of a transformer, on-line live oil filtering technology can purify the transformer oil without powering off the transformer, avoiding the impact on the power grid operation caused by long-term power outages, and has gradually been applied.

[0003] However, during the operation of an on-line live oil filter device, it usually needs to be connected to the transformer through external oil inlet pipes and oil outlet pipes. Affected by factors such as pipeline connection, hose aging, or seal component failure, there is a risk of leakage. In the prior art, most only monitor a single pipe section or a single detection signal, lacking a collaborative detection mechanism for the leakage conditions of the oil inlet pipe, oil outlet pipe, and the interior of the oil filter main body; at the same time, for the risk of abnormal oil shortage in the transformer that may occur during the oil filtering process, there are also no effective real-time identification and linkage control means.

[0004] Once leakage occurs or the transformer oil volume is abnormal during on-line live oil filtering, it is easy to cause a large loss of the transformer insulating oil, which not only affects the normal operation of the transformer, but also brings problems of resource waste and environmental pollution. Therefore, there is an urgent need to provide a leakage detection system and a detection method suitable for on-line live oil filtering conditions to achieve real-time monitoring and safety interlock control of various leakage risks and the risk of oil shortage in the transformer. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the technical solution adopted by the present invention to solve its technical problems is: an on-line live oil filter leakage detection system applied to an on-line live oil filter connected to a transformer, including: An oil inlet pipe leakage detection unit, arranged between the oil outlet of the transformer and the oil inlet of the on-line live oil filter, including a first oil inlet flowmeter, a second oil inlet flowmeter, and an oil inlet pneumatic cut-off valve; An oil outlet pipe leakage detection unit, arranged between the oil outlet of the on-line live oil filter and the oil inlet of the transformer, including a first oil outlet flowmeter, a second oil outlet flowmeter, and an oil outlet pneumatic cut-off valve; An internal leakage detection unit of the main body, arranged at the lowest position inside the body of the on-line live oil filter, including a liquid level detection device; An accumulated flow difference judgment unit, used to periodically compare the accumulated oil inlet flow on the oil outlet side of the transformer with the accumulated oil outlet flow on the oil inlet side of the transformer during the continuous operation of the on-line live oil filter. When the accumulated flow difference between the two continuously exceeds a preset threshold, it is determined that the transformer has a risk of abnormal oil shortage; The control and alarm unit is communicatively connected to the oil inlet pipeline leakage detection unit, the oil outlet pipeline leakage detection unit, the main unit internal leakage detection unit, and the cumulative flow difference judgment unit, respectively. When a leak is detected or there is an abnormal oil shortage risk, the control unit controls the online live oil filter to stop running, and simultaneously closes the oil inlet pneumatic shut-off valve and the oil outlet pneumatic shut-off valve, and outputs an alarm signal.

[0006] Preferably, the oil inlet pipeline leakage detection unit and the oil outlet pipeline leakage detection unit compare the real-time flow or cumulative flow of the corresponding flow meter, and determine that the corresponding pipeline has leaked when the flow difference exceeds a preset threshold.

[0007] Preferably, the cumulative flow difference judgment unit uses a preset detection cycle to periodically sample and accumulate the cumulative inlet flow and cumulative outlet flow to eliminate the impact of operating condition fluctuations during the oil filtration process on the judgment result.

[0008] Preferably, the transformer is determined to have an abnormal oil shortage risk only when the cumulative flow difference exceeds the preset threshold continuously for multiple consecutive detection cycles.

[0009] Preferably, the control and alarm unit is a programmable logic controller (PLC).

[0010] A method for leak detection in an online electrically charged oil filter includes the following steps: S1: During the operation of the online electrostatic oil filter, the flow data of the corresponding flow meters at both ends of the oil inlet pipe and the oil outlet pipe are collected; S2: Compare the flow data of the oil inlet pipe and the oil outlet pipe. When the difference in flow rate exceeds the preset threshold, it is determined that the corresponding pipe is leaking. S3: Collect the detection signal of the liquid level detection device installed at the lowest position inside the online electric oil filter. When an abnormal liquid level is detected, it is determined that a leak has occurred inside the main unit. S4: During the continuous operation of the online live oil filter, the cumulative oil flow rate at the transformer outlet side and the cumulative oil flow rate at the transformer inlet side are periodically accumulated and the difference is judged. When the cumulative flow rate difference continues to exceed the preset threshold, it is determined that the transformer has an abnormal oil shortage risk. S5: When any of the conditions in steps S2, S3 or S4 are met, control the online live oil filter to stop running, close the oil inlet and outlet passages, and output an alarm signal.

[0011] Preferably, the cumulative flow difference determination in step S4 is based on a preset detection period.

[0012] Preferably, the cumulative flow difference in step S4 must continuously exceed the preset threshold for multiple consecutive detection cycles before it is determined that the transformer has an abnormal oil shortage risk.

[0013] Preferably, the closing of the oil inlet and outlet passages in step S5 is performed by interlocking.

[0014] The beneficial effects of this invention are as follows: 1. This invention, by installing front and rear flow meters along the oil flow direction on the oil inlet and outlet pipes respectively, and comparing and judging the corresponding flow data, can directly reflect the leakage status through the difference in flow before and after the pipeline when a leak occurs, avoiding the problem of delayed leakage detection caused by relying solely on single-point flow or manual inspection.

[0015] 2. A liquid level detection device is installed at the lowest position inside the online live oil filter. When a leak occurs at any position inside the equipment and oil accumulates, the oil will collect at the lowest position under the action of gravity. This allows the liquid level detection device to effectively identify the internal leakage status and improve the reliability of detecting internal leaks in the oil filter host.

[0016] 3. A cumulative flow difference judgment unit is set up to accumulate and statistically analyze the inlet and outlet oil flow of the transformer during continuous operation. By using the cumulative flow difference rather than the instantaneous flow as the judgment basis, it can identify abnormal changes in transformer oil volume caused by minor continuous leakage or abnormal operating conditions, and reduce the risk of misjudgment caused by instantaneous flow fluctuations.

[0017] 4. By interlocking the judgment results of oil inlet pipe leakage, oil outlet pipe leakage, main unit internal leakage and abnormal oil shortage state of transformer with equipment operation control, the oil filtration is automatically stopped and the oil circuit is cut off when an abnormal state is detected, thereby reducing transformer insulating oil loss and reducing operational safety risks. Attached Figure Description

[0018] Figure 1 This is a block diagram illustrating the system structure principle of the present invention; Figure 2 This is a flowchart of the detection method of the present invention. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

[0020] The online live-line oil filter forms an online circulating oil circuit with the transformer through an inlet and an outlet oil pipe. One end of the inlet oil pipe is connected to the transformer's outlet, and the other end is connected to the inlet of the online live-line oil filter. Along the oil flow direction, the following are sequentially installed on the inlet oil pipe: a first inlet flow meter, an inlet pneumatic shut-off valve, and a second inlet flow meter.

[0021] The first inlet flow meter is used to detect the inlet flow rate at the transformer outlet, and the second inlet flow meter is used to detect the actual inlet flow rate before entering the online live oil filter. The pipe section between the two is the leakage risk section of the inlet pipeline.

[0022] One end of the oil outlet pipe is connected to the oil outlet of the online live oil filter, and the other end is connected to the oil inlet of the transformer. Along the direction of oil flow, the following are installed sequentially on the oil outlet pipe: a first oil outlet flow meter, an oil outlet pneumatic shut-off valve, and a second oil outlet flow meter.

[0023] The first oil flow meter is used to detect the oil flow rate of the oil filter, and the second oil flow meter is used to detect the actual oil flow rate returning to the transformer. The pipe section between the two is the leakage risk section of the oil outlet pipeline.

[0024] A liquid level detection device is installed at the lowest position inside the online electrified oil filter. This lowest position is where the oil inside the filter naturally collects under the action of gravity. When a leak occurs in any part of the filter, the leaking oil can flow to this position and be detected by the liquid level detection device.

[0025] Each flow meter, level detection device, and pneumatic shut-off valve is connected to the control and alarm unit. The control and alarm unit uses a programmable logic controller (PLC) to perform data acquisition, judgment, and interlocking control.

[0026] When the online electrified oil filter is in operation, the control and alarm unit collects the following data according to a preset sampling period: real-time flow data of the first and second inlet flow meters, real-time flow data of the first and second outlet flow meters, and the detection status signal of the liquid level detection device. This data serves as the basis for leak detection and operational control.

[0027] During the operation of the oil filter, the control and alarm unit compares the flow data from the first and second inlet flow meters. When the difference between the flow rate detected by the first and second inlet flow meters exceeds a preset threshold, the control and alarm unit determines that the flow rates before and after the oil inlet pipe are inconsistent, thus indicating a risk of leakage in the oil inlet pipe.

[0028] Upon determining that a leak has occurred in the oil inlet pipeline, the control and alarm unit executes the following control logic: stops the online energized oil filter from operation; closes the pneumatic shut-off valve for the oil inlet, cutting off the oil inlet passage between the transformer and the oil filter, and outputs the corresponding alarm signal.

[0029] Similarly, during the operation of the oil filter, the control and alarm unit compares the flow data from the first and second oil flow meters. When the flow difference between the first and second oil flow meters exceeds a preset threshold, the control and alarm unit determines that there is a risk of leakage in the oil outlet pipeline.

[0030] Upon determining that a leak has occurred in the oil outlet pipeline, the control and alarm unit controls the online energized oil filter to stop operating, closes the pneumatic shut-off valve for the oil outlet, and simultaneously outputs an alarm signal.

[0031] During the operation of the oil filter, the liquid level detection device continuously monitors whether there is oil accumulation at the lowest point inside the machine. When the liquid level detection device detects an abnormal liquid level signal, the control and alarm unit determines that a leak has occurred inside the online energized oil filter. In this case, the control and alarm unit performs the following operations: stops the operation of the online energized oil filter; simultaneously closes the inlet pneumatic shut-off valve and the outlet pneumatic shut-off valve, and outputs an internal leakage alarm signal for the main unit.

[0032] During continuous operation of the oil filter, the control and alarm unit accumulates and statistically analyzes the inlet and outlet oil flow rates on the transformer's oil outlet side. Within each preset detection cycle, the inlet and outlet oil flow rates are summed, and the corresponding cumulative flow difference is calculated.

[0033] When the cumulative flow difference exceeds the preset threshold within a single detection cycle, the control and alarm unit continues to make cumulative judgments for subsequent detection cycles. When the cumulative flow difference continuously exceeds the preset threshold for multiple consecutive detection cycles, even if the instantaneous flow does not show obvious abnormalities, the control and alarm unit still determines that the transformer has an abnormal oil shortage state.

[0034] After determining that the transformer is in an abnormal oil shortage state, the control and alarm unit controls the online live oil filter to stop running, cuts off the oil inlet and outlet passages, and outputs the corresponding alarm signal.

[0035] In this embodiment, leaks in the inlet pipe, outlet pipe, internal leakage of the main unit, and abnormal oil shortage in the transformer are all independent conditions for triggering shutdown and cutting off the oil circuit. When any condition is triggered, the control and alarm units execute unified interlocking control logic to prevent the leakage from escalating or the transformer oil level from becoming further abnormal.

[0036] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. An online live-line oil filter leak detection system, characterized in that, include: The oil inlet pipeline leakage detection unit is installed between the transformer oil outlet and the online live oil filter oil inlet, and includes a first oil inlet flow meter, a second oil inlet flow meter and an oil inlet pneumatic shut-off valve. The oil outlet pipeline leakage detection unit is installed between the oil outlet of the online live oil filter and the oil inlet of the transformer, and includes a first oil outlet flow meter, a second oil outlet flow meter, and an oil outlet pneumatic shut-off valve. The internal leakage detection unit of the main unit is located at the lowest position inside the body of the online live oil filter, and includes a liquid level detection device; The cumulative flow difference judgment unit is used to periodically compare the cumulative flow of oil entering the transformer outlet side with the cumulative flow of oil exiting the transformer outlet side during the continuous operation of the online live oil filter. When the cumulative flow difference between the two continuously exceeds the preset threshold, it is determined that there is an abnormal oil shortage risk in the transformer. The control and alarm unit is communicatively connected to the oil inlet pipeline leak detection unit, the oil outlet pipeline leak detection unit, the main unit internal leak detection unit, and the cumulative flow difference judgment unit, respectively. When a leak is detected or there is an abnormal oil shortage risk, the control unit controls the online live oil filter to stop running, and simultaneously closes the oil inlet pneumatic shut-off valve and the oil outlet pneumatic shut-off valve, and outputs an alarm signal.

2. The online live-line oil filter leak detection system according to claim 1, characterized in that: The oil inlet pipeline leakage detection unit and the oil outlet pipeline leakage detection unit compare the real-time flow or cumulative flow of the corresponding flow meter. When the flow difference exceeds a preset threshold, it is determined that the corresponding pipeline has leaked.

3. The online live-line oil filter leak detection system according to claim 1, characterized in that: The cumulative flow difference judgment unit uses a preset detection cycle to periodically sample and accumulate the cumulative inlet flow and cumulative outlet flow to eliminate the impact of operating condition fluctuations during the oil filtration process on the judgment result.

4. The online live-line oil filter leak detection system according to claim 3, characterized in that: The transformer is only deemed to have an abnormal oil shortage risk if the cumulative flow difference exceeds the preset threshold continuously for multiple consecutive detection cycles.

5. The online live-line oil filter leak detection system according to claim 1, characterized in that: The control and alarm unit is a programmable logic controller (PLC).

6. A method for detecting leaks in an online live-line oil filter, applied to the online live-line oil filter leak detection system according to any one of claims 1-5, characterized in that, Includes the following steps: S1: During the operation of the online electrostatic oil filter, the flow data of the corresponding flow meters at both ends of the oil inlet pipe and the oil outlet pipe are collected; S2: Compare the flow data of the oil inlet pipe and the oil outlet pipe. When the difference in flow rate exceeds the preset threshold, it is determined that the corresponding pipe is leaking. S3: Collect the detection signal of the liquid level detection device installed at the lowest position inside the online electric oil filter. When an abnormal liquid level is detected, it is determined that a leak has occurred inside the main unit. S4: During the continuous operation of the online live oil filter, the cumulative oil flow rate at the transformer outlet side and the cumulative oil flow rate at the transformer inlet side are periodically accumulated and the difference is judged. When the cumulative flow rate difference continues to exceed the preset threshold, it is determined that the transformer has an abnormal oil shortage risk. S5: When any of the conditions in steps S2, S3 or S4 are met, the online live oil filter is stopped and the oil inlet and outlet passages are closed, and an alarm signal is output.

7. The leakage detection method for an online live-line oil filter according to claim 6, characterized in that: The cumulative flow difference judgment in step S4 is based on a preset detection period.

8. The leakage detection method for an online live-line oil filter according to claim 6, characterized in that: In step S4, the cumulative flow difference must continuously exceed the preset threshold for multiple consecutive detection cycles before it is determined that the transformer has an abnormal oil shortage risk.

9. The leakage detection method for an online electrostatic oil filter according to claim 6, characterized in that: The closing of the oil inlet and outlet passages in step S5 is an interlocked operation.

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