A transformer on-line oil filtering device structure and its control strategy

Abstract

The application provides a transformer online oil filter device structure and a control strategy thereof. The device is provided with an electric control safety valve and a pressure regulating valve at an oil inlet, and can realize automatic closing, starting and stopping and pressure regulating of an oil circuit according to a control signal. In addition, the application provides a control strategy of the transformer online oil filter device, which realizes real-time online monitoring of pressure and oil flow rate data of an inlet and outlet oil pipe and an oil valve state, sets oil speed and pressure mutation monitoring thresholds, automatically controls components such as a safety valve and a pressure regulating valve according to changes of real-time sampling data before and after, and prevents fault alarm. Related operation data and alarm information are synchronously transmitted to a remote terminal, and the safety, reliability and online monitoring capacity of the oil filter device are further improved.

Description

Technical Field

[0001] This invention belongs to the field of electrical equipment and electrical safety technology, and specifically relates to the structure and control strategy of an online oil filtration device for transformers. Background Technology

[0002] Live-line oil filtration is an important auxiliary device for transformers, ensuring the purity and cleanliness of the transformer oil. Its main function is to absorb moisture and various impurities during transformer operation, preventing moisture and gases in the transformer oil from causing insulation aging and faults, and preventing impurities from causing poor oil flow, which affects operating efficiency and stability. Live-line oil filtration plays a crucial role in improving the insulation performance and cooling effect of transformer oil, ensuring normal transformer operation, and enhancing the reliability and safety of the transformer.

[0003] A live oil filtration system typically consists of an oil pump motor, pressure gauge, inlet and outlet oil pipes, oil valves, connecting flanges, filter elements, filter tank, and control components. The inlet and outlet oil pipes are connected to the outlet and inlet oil pipes of the tap changer, respectively. After the oil pump motor starts, pressure draws the transformer oil from the tap changer through the connecting pipes into the filter tank. The filtered oil is then injected back into the tap changer.

[0004] Oil filtration devices frequently experience malfunctions during operation, such as air accumulation in the pipes, excessively high or low oil pressure, excessively fast oil flow, and insufficient vacuum, leading to numerous production accidents. Improper operation settings of the oil filtration device are often the root cause of component damage and erroneous activation of the transformer's heavy gas protection system. Existing transformer oil filtration devices generally lack comprehensive online status monitoring functions, automatic voltage regulation structures, and control measures. Manual inspections are insufficient to promptly adjust the device's status based on oil pressure, flow rate, and other conditions within the filtration device. When abnormal conditions such as oil pressure and flow rate occur, they easily trigger erroneous activation of the transformer's heavy gas protection system, rendering inspections reactive. Summary of the Invention

[0005] To address the shortcomings and deficiencies of existing technologies, this invention designs a structure and control strategy for an online oil filtration device for transformers. The online oil filtration device mainly consists of components such as an oil pump motor, pressure gauge, inlet and outlet oil pipes, shut-off valve, safety valve, pressure regulating valve, connecting flange, filter element, filter tank, pressure sensor module, oil flow rate sensor module, sampling valve, remote terminal, local control cabinet, and device housing. By real-time acquisition and uploading of parameters such as oil flow rate and pipeline pressure, it can achieve both remote and local operating modes.

[0006] The device is equipped with an electrically controlled safety valve and a pressure regulating valve at the oil inlet, which can automatically shut down, start, stop, and regulate the oil circuit according to control signals. Furthermore, a control strategy for the transformer online oil filtration device is proposed. This strategy involves real-time online monitoring of inlet and outlet oil pipe pressure and flow rate data, as well as the status of oil valves. Thresholds for monitoring sudden changes in oil speed and pressure are set. Based on changes in real-time sampled data, the device automatically controls and executes components such as the safety valve and pressure regulating valve to prevent fault alarms. Relevant operating data and alarm information are synchronously transmitted to a remote terminal, further enhancing the safety, reliability, and online monitoring capabilities of the oil filtration device.

[0007] The present invention specifically adopts the following technical solution:

[0008] An online oil filtration device for transformers is described, comprising an electrically controlled safety valve and a pressure regulating valve installed at the oil inlet to control the shut-off, start-up, and pressure regulation of the oil circuit according to control signals; and real-time online monitoring of inlet and outlet oil pressure and oil flow rate data, as well as the status of the oil valves, by installing pressure sensor modules and oil flow rate sensor modules, and setting monitoring thresholds for sudden changes in oil speed and pressure. Based on changes in real-time sampled data, the safety valve and pressure regulating valve are controlled to prevent fault alarms.

[0009] Furthermore, the safety valve is installed on the oil inlet pipe, is electrically controlled, and has two states: open and closed.

[0010] The pressure regulating valve is installed on the oil inlet pipe, is electrically controlled, and has two states: open and closed. It is used to adjust the pressure inside the oil filtration device.

[0011] Furthermore, the oil pressure sensor module includes an inlet pipe oil pressure sensor and an outlet pipe oil pressure sensor, which are respectively installed on the inlet pipe and outlet pipe of the oil filter device to collect the pressure data of the inlet and outlet pipes of the oil filter device in real time and upload them to a remote terminal.

[0012] The oil flow rate sensing module includes an inlet pipe oil flow rate sensor and an outlet pipe oil flow rate sensor, which are installed on the inlet pipe and outlet pipe of the oil filtration device, respectively, to collect the oil flow rate data of the inlet and outlet pipes of the oil filtration device in real time and upload it to a remote terminal.

[0013] Furthermore, operational data and alarm information are simultaneously transmitted to remote terminals.

[0014] Furthermore, an oil inlet pipe shut-off valve and an oil outlet pipe shut-off valve are provided; the oil inlet pipe shut-off valve is used to control whether the transformer tap changer chamber is connected to the oil inlet pipe of the oil filter; the oil outlet pipe shut-off valve is used to control whether the transformer tap changer chamber is connected to the oil outlet pipe of the oil filter.

[0015] Furthermore, a sampling valve is installed and connected to the oil filtration device via a pipeline to sample the transformer oil inside the oil filtration machine.

[0016] Furthermore, a local control cabinet is also provided, equipped with a remote / local switching switch, which allows the local control cabinet to control the working status of the oil filter device in both remote and local modes; the local control cabinet is also equipped with oil pump motor start / stop and on / off control buttons for each oil pipe valve.

[0017] In addition, a control strategy is provided for the structure of the online oil filtration device for transformers:

[0018] The output signal of the pressure sensor is set to S, the output signal of the oil flow sensor is set to Y, the output signal of the pressure change rate is set to KS, the output signal of the oil flow change rate is set to KY, the output signal of the safety valve is set to A1, and the output signal of the pressure regulating valve is set to T1. When the pressure difference between the inlet / outlet pipe and the outlet pipe is greater than the set value of 10 kPa, the output signal of the pressure sensor is 1, and 0 in other cases. When the oil flow at the inlet / outlet pipe and the outlet pipe is greater than the set value of 0.5 m / s, the output signal of the oil flow sensor is 1, and 0 in other cases. The specific formulas are shown in equations (1) and (2).

[0019]

[0020]

[0021] The pressure mutation rate is calculated from the rate of change of pressure difference within adjacent sampling time intervals. When the pressure difference changes too quickly within adjacent sampling time intervals, the pressure mutation rate output signal KS is 1, and 0 in other cases.

[0022] The oil flow mutation rate is calculated from the rate of change of oil flow within adjacent sampling time intervals. When the oil flow changes too quickly within adjacent sampling time intervals, the oil flow mutation rate output signal KS is 1, and in other cases it is 0. The specific formulas are shown in equations (3) and (5):

[0023]

[0024]

[0025] Furthermore, the opening and closing states of the safety valve are determined by the pressure sensor, the oil flow sensor, the pressure change rate, and the oil flow change rate. When any of these signals is triggered, the safety valve will close, and A1 will output 1; otherwise, A1 will output 0. At the same time, if the pressure difference continues to increase, the pressure regulating valve T1 will output 1 to release the oil pressure. The start and stop states of the motor are related to the safety valve. When the safety valve is closed, the motor lockout output signal will be 1; otherwise, it will be 0. The specific formulas are shown in (5), (6), and (7).

[0026]

[0027]

[0028]

[0029] Compared to existing technologies, this invention and its preferred embodiment enable full-system monitoring of the online transformer oil filtration device. By adding safety valves and pressure regulating valves, protection against abnormal conditions such as excessive oil pressure and excessive oil flow rate is achieved. Simultaneously, real-time online monitoring of inlet and outlet oil pipe pressure and oil flow rate data, as well as oil valve status, is implemented. Based on data processing results, the actuators are automatically controlled, and data and alarm information are transmitted to a remote terminal, thus improving the safety and reliability of the oil filtration device. Attached Figure Description

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0032] Figure 1 This is a schematic diagram of the system composition according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the structural composition of an embodiment of the present invention;

[0034] Figure 3 This is a control flow diagram of an embodiment of the present invention;

[0035] Figure 4 This is a simplified schematic diagram of the control logic in an embodiment of the present invention. Detailed Implementation

[0036] To make the features and advantages of this patent more apparent and understandable, specific embodiments are provided below for detailed explanation:

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components described and shown in the accompanying drawings can generally be combined and designed in different configurations. Therefore, the following detailed description of selected embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but only to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] The specific solution of the present invention will be further described below with reference to the accompanying drawings and embodiments:

[0040] like Figure 1 , Figure 2 As shown, this embodiment of the invention first proposes a transformer online oil filtration device structure based on the existing structure, including an oil pump motor 1, an oil pipe 2, a connecting flange 3, a filter module 4, a shut-off valve 5, a sampling valve 6, a safety valve 7, a pressure regulating valve 8, an oil pressure sensor module 9, an oil flow rate sensor module 10, a local control cabinet 11, a device housing 12, and a remote terminal.

[0041] The inlet and outlet of the oil pump motor 1 are connected to the oil inlet pipe of the oil filter and the filtration system, respectively.

[0042] Oil pipe 2 includes an inlet pipe 21 and an outlet pipe 22, and the diameters of the inlet pipe 21 and the outlet pipe 22 are the same.

[0043] The connecting flange 3 includes an oil inlet flange 31 and an oil outlet flange 32, which are respectively connected to the oil outlet and oil inlet of the transformer tap changer.

[0044] The filter module 4 includes a pressure gauge 41 and a filter canister 42, which contains a filter element 43. The pressure gauge 41 displays the pressure value in the filter canister, and the filter element 43 filters and absorbs water and free carbon impurities in the oil.

[0045] The shut-off valve 5 includes an inlet pipe shut-off valve 51 and an outlet pipe shut-off valve 52. The inlet pipe shut-off valve 51 can control whether the transformer tap changer chamber is connected to the oil filter inlet pipe, and the outlet pipe shut-off valve 52 can control whether the transformer tap changer chamber is connected to the oil filter outlet pipe.

[0046] The sampling valve 6 is connected to the filter module 4 and can be manually opened and closed to sample the transformer oil inside the oil filter.

[0047] Safety valve 7 is installed on oil inlet pipe 21. Safety valve 7 is electrically controlled and has two states: open and closed. Its control signal is determined by the corresponding control strategy.

[0048] The pressure regulating valve 8 is installed on the oil inlet pipe 21. The pressure regulating valve 8 is electrically controlled and has two states: open and closed. The adjustment state of the valve is determined by a certain control strategy and is used to adjust the pressure inside the oil filter device.

[0049] The oil pressure sensor module 9 includes an inlet pipe oil pressure sensor 101 and an outlet pipe oil pressure sensor 102, which are respectively installed on the inlet pipe 21 and outlet pipe 22 of the oil filter device, and collect the pressure data of the inlet and outlet pipes of the oil filter device in real time and upload them to the remote terminal.

[0050] The oil flow rate sensing module 10 includes an oil flow rate sensor 101 in the inlet pipe and an oil flow rate sensor 102 in the outlet pipe, which are respectively installed on the oil inlet pipe 21 and the oil outlet pipe 22 of the oil filter device. The module collects the oil flow rate data of the oil filter device in the inlet and outlet pipes in real time and uploads it to a remote terminal.

[0051] The local control cabinet 11 has a remote / local switch 111, which allows the local control cabinet to control the working status of the oil filter device in both remote and local modes. The local control cabinet contains control buttons for starting and stopping the oil pump motor and for switching on and off various oil pipe valves.

[0052] The outer casing 12 integrates the above structures 1 to 11 and serves a protective function.

[0053] Corresponding to the above device structure, the transformer online oil filtration device monitoring and control method has two working modes: automatic mode and manual mode.

[0054] In automatic mode, data such as inlet and outlet oil pipe pressure, oil flow rate, motor running time, and oil valve position are transmitted to the control cabinet for processing. The control cabinet controls the actuators based on the processing results to start and stop the oil pump motor and open and close the oil valve. The monitoring data and alarm signals are then uploaded to the remote terminal via the network server to achieve real-time online monitoring and control.

[0055] In manual mode, the remote terminal sends start / stop commands to the oil pump motor and electric oil valve via the local control cabinet, enabling remote manual start / stop of the oil pump motor and opening / closing of the oil valve.

[0056] Corresponding to the above structures and control methods, such as Figure 3 , Figure 4 As shown, the control strategy is as follows, where the control logic of the local control cabinet in automatic mode is:

[0057] The output signal of the pressure sensor is set to S, the output signal of the oil flow sensor is set to Y, the output signal of the pressure change rate is set to KS, the output signal of the oil flow change rate is set to KY, the output signal of the safety valve is set to A1, and the output signal of the pressure regulating valve is set to T1. When the pressure difference between the inlet / outlet pipe and the outlet pipe is greater than the set value of 10 kPa, the output signal of the pressure sensor is 1; otherwise, it is 0. When the oil flow at the inlet / outlet pipe and the outlet pipe is greater than the set value of 0.5 m / s, the output signal of the oil flow sensor is 1; otherwise, it is 0. The specific formulas are shown in equations (1) and (2):

[0058]

[0059]

[0060] The pressure mutation rate is calculated from the rate of change of pressure difference within adjacent sampling time intervals. When the pressure difference changes too rapidly within adjacent sampling time intervals, the pressure mutation rate output signal KS is 1; otherwise, it is 0. Similarly, the oil flow mutation rate is calculated from the rate of change of oil flow within adjacent sampling time intervals. When the oil flow changes too rapidly within adjacent sampling time intervals, the oil flow mutation rate output signal KS is 1; otherwise, it is 0. The specific formulas are shown in equations (3) and (5):

[0061]

[0062]

[0063] The opening and closing states of the safety valve are determined by the pressure sensor, oil flow sensor, pressure change rate, and oil flow change rate. When any of these signals is triggered, the safety valve will close, and A1 will output 1; otherwise, A1 will output 0. Simultaneously, if the pressure difference continues to increase, the pressure regulating valve T1 will output 1, releasing the oil pressure. The start and stop states of the motor are associated with the safety valve. When the safety valve is closed, the motor M lockout output signal is 1; otherwise, it is 0. Specific formulas are shown in (5), (6), and (7).

[0064]

[0065]

[0066]

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

[0068] This patent is not limited to the above-described preferred embodiment. Anyone can derive other forms of transformer online oil filtration device structure and control strategy based on the inspiration of this patent. All equivalent changes and modifications made within the scope of this patent application shall fall within the scope of this patent.

Claims

1. A control method based on the structure of an online oil filtration device for transformers, characterized in that: The online oil filtration device includes the following structure: An electronically controlled safety valve and a pressure regulating valve are installed at the oil inlet to shut down, start, stop, and regulate the oil circuit according to control signals. The oil pressure sensor module and the oil flow rate sensor module are installed to monitor the pressure and flow rate data of the inlet and outlet oil pipes and the status of the oil valves in real time. Thresholds for monitoring sudden changes in oil speed and pressure are set. The safety valve and the pressure regulating valve are controlled according to the changes in real-time sampling data before and after to prevent fault alarms. The safety valve is installed on the oil inlet pipe, is electrically controlled, and has two states: open and closed. The pressure regulating valve is installed on the oil inlet pipe, is electrically controlled, and has two states: open and closed. It is used to adjust the pressure inside the oil filtration device. The oil pressure sensor module includes an inlet oil pressure sensor and an outlet oil pressure sensor, which are installed on the inlet and outlet oil pipes of the oil filter device, respectively, to collect the pressure data of the inlet and outlet oil pipes of the oil filter device in real time and upload them to a remote terminal. The oil flow rate sensor module includes an oil flow rate sensor in the inlet pipe and an oil flow rate sensor in the outlet pipe, which are respectively installed on the oil inlet pipe and the oil outlet pipe of the oil filter device to collect the oil flow rate data of the oil filter device in the inlet and outlet pipes in real time and upload them to a remote terminal. The system is equipped with an inlet pipe shut-off valve and an outlet pipe shut-off valve; the inlet pipe shut-off valve is used to control whether the transformer tap changer chamber is connected to the oil filter inlet pipe; the outlet pipe shut-off valve is used to control whether the transformer tap changer chamber is connected to the oil filter outlet pipe. It is also equipped with a local control cabinet with a remote / local switch, which allows the local control cabinet to control the working status of the oil filter device in both remote and local modes. The local control cabinet is also equipped with oil pump motor start / stop and oil pipe valve on / off control buttons. The control method includes: The output signal of the pressure sensor is set to S, the output signal of the oil flow sensor is set to Y, the output signal of the pressure change rate is set to KS, the output signal of the oil flow change rate is set to KY, the output signal of the safety valve is set to A1, and the output signal of the pressure regulating valve is set to T1. When the pressure difference between the inlet / outlet pipe and the outlet pipe is greater than the set value of 10 kPa, the output signal of the pressure sensor is 1, and 0 in other cases. When the oil flow at the inlet / outlet pipe and the outlet pipe is greater than the set value of 0.5 m / s, the output signal of the oil flow sensor is 1, and 0 in other cases. The specific formulas are shown in equations (1) and (2). The pressure mutation rate is calculated from the rate of change of pressure difference within adjacent sampling time intervals. When the pressure difference changes too quickly within adjacent sampling time intervals, the pressure mutation rate output signal KS is 1, and 0 in other cases. The oil flow mutation rate is calculated from the rate of change of oil flow within adjacent sampling time intervals. When the oil flow changes too quickly within adjacent sampling time intervals, the output signal KS of the oil flow mutation rate is 1, and it is 0 in other cases. The specific formulas are shown in equations (3) and (5). As shown:

2. The control method based on the structure of the online oil filtration device for transformers according to claim 1, characterized in that: Operational data and alarm information are transmitted synchronously to the remote terminal.

3. The control method based on the structure of the online oil filtration device for transformers according to claim 1, characterized in that: A sampling valve is installed and connected to the oil filtration device via a pipeline to sample the transformer oil inside the oil filtration machine.

4. The control method based on the structure of the online oil filtration device for transformers according to claim 1, characterized in that: The opening and closing state of the safety valve is determined by the pressure sensor, oil flow sensor, pressure change rate, and oil flow change rate. When any of these signals is triggered, the safety valve will close and A1 output will be 1; otherwise, A1 will be 0. At the same time, if the pressure difference continues to increase, T1 output will be 1, releasing the oil pressure. The start and stop state of the motor is related to the safety valve. When the safety valve is closed, the motor lockout output signal will be 1; otherwise, it will be 0. The specific formulas are shown in (5), (6), and (7).

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