Transformer cooling control device and water spraying arrangement method

Abstract

The invention discloses a transformer cooling control device and a water spray arrangement method.The transformer cooling control device comprises an electrical control module and a water loop module, the electrical control module comprises a station end monitoring background for collecting real-time information of a transformer, and the station end monitoring background establishes communication with an auxiliary equipment gateway machine in a read-only mode; the auxiliary equipment gateway machine is internally provided with a PID control strategy and intercommunicates with the new-generation centralized control system and the communication gathering equipment, the communication gathering equipment communicates with the communication receiving module in a wireless transmission mode, and the communication receiving module is embedded in the control device; the water loop module comprises a proportional electromagnetic valve, a flow meter and a spraying pipe, a small spraying hole is formed in the spraying pipe, and by means of an original device in a station and a PID control strategy, waste of water resources is reduced while automatic spraying and cooling of the transformer are achieved, and the deployment cost of the device is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer cooling, and in particular relates to a transformer cooling control device and a water spraying arrangement method. Background Art

[0002] As a key equipment in the power system, the stability and safety of the transformer are of vital importance. The transformer will generate a lot of heat during operation, especially during high temperatures in summer or peak load periods. If this heat cannot be dissipated in time, it will affect the normal operation and life of the transformer over time. Existing transformer auxiliary cooling technologies include air cooling and water cooling. Air cooling achieves the effect of heat dissipation by using a blower to continuously blow air through the transformer heat sink, but the blower consumes a lot of power and has serious noise pollution, so it is not suitable for installation in urban substations. As a means of auxiliary heat dissipation, water cooling essentially exchanges heat with the heat sink through flowing water, takes away the heat from the heat sink, and completes the cooling of the heat sink.

[0003] The existing water cooling spray method is relatively simple. Usually, multiple spray valves are arranged on the top of the transformer heat sink. The spray water flow of this method can only cover part of the top area of ​​the heat sink. The water column formed by the water flowing down the side wall of the heat sink has a relatively small water film area on the heat sink, which makes the heat exchange efficiency low and leads to poor spray cooling effect.

[0004] The existing water cooling control method also has shortcomings. It relies on manual control of the start and stop of the spray device, and cannot adjust the spray according to the transformer load rate and oil temperature, which consumes a lot of water resources. The cooling method that relies on automatic control often requires the deployment of a large amount of hardware such as temperature sensing devices and automatic control devices, with high deployment costs, decentralized system operation, and great management difficulty. In addition, most existing substations adopt unattended mode, and there is a certain time lag in the manual start and stop of the water spray device. The delayed start cannot achieve an effective cooling effect, and the delayed shutdown wastes a lot of water resources. It is also a great waste of manpower and material resources on the round trip. Therefore, it is necessary to design a transformer cooling control device and a water spray arrangement method to solve the above problems. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a transformer cooling control device and a water spray arrangement method. By combining the temperature information of the transformer body and the transformer load information, according to the real-time operating status of the transformer, a PID control strategy is used in combination with an efficient heat dissipation spray arrangement method to accurately cool the transformer in a multi-gradient manner, thereby ensuring the safe operation of the transformer while saving water, and facilitating the later maintenance of the transformer.

[0006] In order to achieve the above technical effects, the technical solution adopted by the present invention is: A transformer cooling control device comprises an electrical control module and a water circuit module. The electrical control module comprises a station-end monitoring background for collecting real-time information of the transformer. The station-end monitoring background is connected to the auxiliary equipment gateway in a read-only manner, and the auxiliary equipment gateway executes a PID control strategy; the auxiliary equipment gateway is connected to the centralized control system and the communication summary device, and the communication summary device is connected to the communication receiving module in a wireless transmission manner; the water circuit module comprises a proportional solenoid valve, which is connected in series with the inspection valve and then in parallel with the manual valve. A flow meter is connected to the water inlet side of the manual valve, and the water inlet side of the flow meter is connected to the entire water circuit main pipeline. The main pipeline is divided into two branch pipelines with the same arrangement. The terminals of the two branch pipelines are spray pipes, and the two spray pipes respectively perform water cooling auxiliary cooling on the #main transformer and the #main transformer.

[0007] Preferably, the auxiliary equipment gateway transmits the received real-time information of transformer temperature and load rate to the new generation centralized control system, performs manual data monitoring of the main transformer water spray device and determines whether to issue a command to start and stop the device, thereby remotely controlling the proportional solenoid valve; the auxiliary equipment gateway automatically starts the automatic control of the proportional solenoid valve through the received transformer temperature and load rate; the new generation centralized control system transmits the execution instruction to the auxiliary equipment gateway through the data network. When the remote control start instruction is issued and the auxiliary equipment gateway is turned on, the time lag period start up, After failure, the built-in PID control strategy is turned on, and the priority of remote control is set higher than automatic control. The PID control strategy is as follows: ; In the formula Indicates actual temperature With preset temperature The difference, is the integral term of the difference, which is used to eliminate the static error of the entire control process. The differential term of the error can achieve precise control by responding to the change of the preset temperature value more quickly. , and It is the parameter of PID control strategy, which determines the response speed and stability of the whole control process; , and The parameters are given by the manufacturer, where The output signal is transmitted to the execution module and then converted into a current signal to control the proportional solenoid valve; The proportional solenoid valve can be divided into four proportional opening positions according to the size of the given temperature signal, and the opening degrees are 0, , and 1, the specific working method is: When the actual temperature Less than the preset temperature When , the proportional solenoid valve opening is set to 0, that is, closed state; When the actual temperature exist ~( +5℃), the proportional solenoid valve opening is set to ; When the actual temperature exist( +5℃)~( +10℃), the proportional solenoid valve opening is set to ; When the actual temperature Not less than ( +10℃), the proportional solenoid valve opening is set to 1.

[0008] Preferably, the auxiliary equipment gateway has a built-in time lag function that coordinates with the PID control strategy, and the specific method is as follows: The transformer temperature is positively correlated with the transformer load factor, and the load factor increase takes precedence over the temperature increase. Less than the preset temperature When the load rate is still greater than the safety value , set the time delay period , Then judge the load rate again, and repeat the judgment until the load rate is less than the safe value. , at this time the proportional solenoid valve is closed.

[0009] Preferably, the communication receiving module adopts LORA433MHZ wireless communication technology, which is embedded in the control device TIAM335X. The control device has a built-in manual start function button. When the manual start is turned on, the manual start information is transmitted to the auxiliary device gateway through communication. The PID control strategy is closed at this time. During this period, the PID control strategy is turned on again, and then the proportional opening gear of the proportional solenoid valve is manually adjusted by the control device to manually control the proportional solenoid valve to work when the PID control strategy cannot effectively control it.

[0010] Preferably, a spray pipe and a proportional solenoid valve are installed in the water circuit module, and the arrangement is as follows: The spray pipe is installed at the top position between the adjacent heat sink bodies of the transformer. The spray holes arranged on the spray pipe have a spacing of 1 cm between adjacent spray holes. The angle of the water column ejected through the spray hole relative to the heat sink is set to 45°. Through comparative experiments, the water film formed by the water column on the heat sink in this arrangement has a better coverage area. The proportional solenoid valve is connected in series with the inspection valve and then in parallel with the manual valve to prevent the manual valve from being opened or closed when the proportional solenoid valve fails. A flow meter for detecting and controlling the water flow is connected to the water inlet side of the manual valve. A drain valve is set at the lowest point of the pipe on the water outlet side of the manual valve to manually drain the remaining water in the pipe when the temperature is low to prevent the pipe from freezing and cracking.

[0011] The beneficial effects of the present invention are as follows: 1. The present invention combines the temperature information of the transformer body and the transformer load information, and according to the real-time operating state of the transformer, uses the PID control strategy combined with the efficient heat dissipation spray arrangement to realize multi-gradient temperature control to accurately cool the transformer, thereby ensuring the safe operation of the transformer and saving water, and facilitating the later maintenance of the transformer; 2. In addition to the intelligent control method, the remote communication control device and the multi-proportional solenoid valve of the present invention also retain human intervention measures, increase system redundancy safety, and ensure stable operation of the entire device.

[0012] 3. The spray cooling device of the present invention fully utilizes the temperature sensing device of the transformer body and some of the original communication equipment in the substation, with a small number of deployed hardware and low cost, and is uniformly connected to a new generation of centralized control system, without the need to build a self-built system, and has great management advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is an overall flow chart of the control method of an embodiment of the present invention; Figure 2 This is a schematic diagram of the planar structure of a water circuit according to an embodiment of the present invention; Figure 3 A side view of a spray pipe arranged on the outer wall of a heat sink according to an embodiment of the present invention; Figure 4 A partial view showing a spray pipe arranged between heat sinks according to an embodiment of the present invention; Figure 5 This is a diagram of the water film heat transfer process according to an embodiment of the present invention; Figure 6 It is a flow chart of the temperature control principle of an embodiment of the present invention; In the figure: main pipeline 1, spray pipe 2, proportional solenoid valve 3, flow meter 4, manual valve 5, inspection valve 6, manual main valve 7, drain valve 8, heat sink 9, spray hole 10. DETAILED DESCRIPTION

[0014] Embodiment 1: like Figure 1As shown, a transformer cooling control device includes an electrical control module and a water circuit module. The electrical control module includes a station-end monitoring background for collecting real-time information of the transformer. The station-end monitoring background is connected to the auxiliary equipment gateway in a read-only manner, and the auxiliary equipment gateway executes a PID control strategy; the auxiliary equipment gateway is connected to the centralized control system and the communication summary device, and the communication summary device is connected to the communication receiving module in a wireless transmission manner; the water circuit module includes a proportional solenoid valve 3, which is connected in series with the inspection valve 6 and then in parallel with the manual valve 5. The water inlet side of the manual valve 5 is connected to a flow meter 4, and the water inlet side of the flow meter 4 is connected to the entire water circuit main pipeline 1. The main pipeline 1 is connected to two branch pipelines with the same arrangement. The terminals of the two branch pipelines are spray pipes 2, and the two spray pipes 2 respectively perform water cooling auxiliary cooling on the 1# main transformer and the 2# main transformer.

[0015] Preferably, the auxiliary equipment gateway transmits the received real-time information of transformer temperature and load rate to the new generation centralized control system, performs manual data monitoring of the main transformer water spray device and determines whether to issue a command to start and stop the device, thereby remotely controlling the proportional solenoid valve 3; the auxiliary equipment gateway automatically starts the automatic control of the proportional solenoid valve 3 through the received transformer temperature and load rate; the new generation centralized control system transmits the execution instruction to the auxiliary equipment gateway through the data network. When the remote control start instruction is issued and the auxiliary equipment gateway is turned on, the time lag period start up, After failure, the built-in PID control strategy is turned on, and the priority of remote control is set higher than automatic control. The PID control strategy is as follows: ; In the formula Indicates actual temperature With preset temperature The difference, is the integral term of the difference, which is used to eliminate the static error of the entire control process. The differential term of the error can achieve precise control by responding to the change of the preset temperature value more quickly. , and It is the parameter of PID control strategy, which determines the response speed and stability of the whole control process; , and The parameters are given by the manufacturer, where The output signal is transmitted to the execution module and then converted into a current signal for controlling the proportional solenoid valve 3; The proportional solenoid valve 3 can be divided into four proportional opening positions according to the size of the given temperature signal, and the opening degrees are 0, , and 1, the specific working method is: When the actual temperature Less than the preset temperature When , the opening of proportional solenoid valve 3 is set to 0, that is, closed state; When the actual temperature exist ~ When the temperature is between +5℃, the opening of proportional solenoid valve 3 is set to ; When the actual temperature exist +5℃~ When the temperature is between +10℃, the opening of proportional solenoid valve 3 is set to ; When the actual temperature Not less than +10℃, the opening of proportional solenoid valve 3 is set to 1.

[0016] Preferably, the auxiliary equipment gateway has a built-in time lag function that coordinates with the PID control strategy, and the specific method is as follows: The transformer temperature is positively correlated with the transformer load factor, and the load factor increase takes precedence over the temperature increase. Less than the preset temperature When the load rate is still greater than the safety value , set the time delay period , Then judge the load rate again, and repeat the judgment until the load rate is less than the safe value. , at this time, the proportional solenoid valve 3 is closed.

[0017] Preferably, the communication receiving module adopts LORA433MHZ wireless communication technology, which is embedded in the control device TIAM335X. The control device has a built-in manual start function button. When the manual start is turned on, the manual start information is transmitted to the auxiliary device gateway through communication. The PID control strategy is closed at this time. During this period, the PID control strategy is turned on again, and then the proportional opening gear of the proportional solenoid valve is manually adjusted by the control device to manually control the proportional solenoid valve 3 to work when the PID control strategy cannot effectively control.

[0018] Preferably, a spray pipe 2 and a proportional solenoid valve 3 are installed in the water circuit module, and the arrangement is as follows: The spray pipe 2 is installed at the top position between the adjacent heat sinks 9 of the transformer. The spray holes 10 arranged on the spray pipe 2 have a spacing of 1 cm between adjacent spray holes 10. The angle of the water column ejected through the spray hole 10 relative to the heat sink 9 is set to 45°. Through comparative experiments, the water film coverage area formed by the water column on the heat sink 9 is better in this arrangement; the proportional solenoid valve 3 is connected in series with the inspection valve 6 and then in parallel with the manual valve 5, so that the manual valve 5 can be opened or closed when the proportional solenoid valve 3 fails. The water inlet side of the manual valve 5 is connected to a flow meter 4 for detecting and controlling the water flow rate. A drain valve 8 is arranged at the lowest point of the pipe on the water outlet side of the manual valve 5, which can be used to manually discharge the remaining water in the pipe when the temperature is low to prevent the pipe from freezing and cracking.

[0019] Embodiment 2: like Figure 2~Figure 4 As shown, the specific arrangement of the water circuit of the present invention includes a proportional solenoid valve, which is connected in series with a maintenance valve and then in parallel with a manual valve. A flow meter is connected to the water inlet side of the manual valve, and the water inlet side of the flow meter is connected to the main pipeline of the entire water circuit. The main pipeline is divided into two branch pipelines with the same arrangement and working principle. The terminals of the two branch pipelines, namely, spray pipes, respectively perform water cooling to assist in cooling the 1# main transformer and the 2# main transformer, and the spray pipes are made of PVC.

[0020] The proportional solenoid valve is connected in series with the inspection valve and then in parallel with the manual valve to prevent the manual valve from being opened or closed when the proportional solenoid valve fails. A flow meter for detecting and controlling the water flow is connected to the water inlet side of the manual valve. A drain valve is set at the lowest point of the pipe on the water outlet side of the manual valve to manually drain the remaining water in the pipe when the temperature is low to prevent the pipe from freezing and cracking.

[0021] The spray pipe is installed at the top position between the adjacent heat sink bodies of the transformer. The spray holes arranged on the spray pipe are set at a spacing of 1 cm between adjacent spray holes. The angle of the water column ejected through the spray hole relative to the heat sink is set to 45°. The comparative experiment verifies that the water film formed by the water column on the heat sink in this arrangement has a better coverage area. The following is the experimental verification principle of this parameter scheme: When the transformer oil with high temperature flows, it will transfer the heat from the inner wall of the heat sink to the outer wall of the heat sink. If the water film on the outer wall of the heat sink is not completely covered, there will be dry spots. The distribution of water film and dry spots and the principle of water film convection heat dissipation are as follows: Figure 5 As shown, the specific formula is: ; In the formula, Q is the total heat transfer, Exchange heat between dry spots and air, is the heat dissipation of water film and air, , , They are the heat that the water film does not dissipate, the heat that the water film transfers to the air in the form of latent heat of vaporization, and the convection heat between the water film and the air. is the heat transfer coefficient of the dry spot, is the mass transfer coefficient, is the water film coverage, is the latent heat of vaporization coefficient, , , The heat sink outer wall temperature and the air inlet and outlet temperatures are respectively, , is the inlet and outlet temperature of water, S is the heat exchange surface area, , are the air inlet and outlet humidity contents, , , m are the moisture content at the gas-liquid interface, the constant-pressure specific heat capacity of water and the mass flow rate of water respectively.

[0022] From the heat dissipation principle, it can be seen The larger the water film coverage area The larger the size, the better the heat dissipation effect. The main factors affecting the water film coverage are the jet incident angle and spray hole spacing , the specific empirical formula is: ; in , , is a positive real number, which shows that the larger the incident angle of the jet, the easier it is to cause splashing and rebound, resulting in The smaller the jet incident angle, the greater the free travel of the water column in the air, which will also cause the outer wall of the heat sink to At the same time, the larger the distance between the spray holes, that is, the fewer the number of holes, the splashing phenomenon will also occur. On the contrary, the more holes there are, the water columns may interfere with each other before reaching the heat sink, resulting in a small water film coverage area.

[0023] In order to obtain a better set of parameters, a simulation experiment was set up, using painted steel plates to simulate heat sinks, current generators to simulate heat sources, flow meters, and PVC water pipe components. Therefore, this experiment can calculate the coverage of the water film by analyzing the steel plate temperature field captured by the infrared thermal imager and combining it with image processing methods.

[0024] In experiment 1, the spray hole spacing was set They are 3cm, 2.5cm, 1cm, and 0.5cm respectively, and the jet incidence angle The uniform angle is 60°. After thermal imaging and image processing, their water film coverage rates are 64.85%, 74.12%, 80.73%, and 79.44% respectively. In Experiment 2, the spray hole spacing is set is 1cm, the jet incident angle They are 30°, 45°, 60°, and 90° respectively. The water film coverage after processing and calculation They correspond to 71.31%, 84.59%, 80.73% and 66.52% respectively; therefore, through Experiments 1 and 2, it can be concluded that when the jet incident angle is 45° and the spray hole spacing is 1 cm, this arrangement has a better spraying effect.

[0025] Embodiment three: Figure 1 An electrical control module is disclosed, the electrical control module includes a station-side monitoring background that collects real-time information of the transformer, the station-side monitoring background establishes communication with an auxiliary device gateway in a read-only manner, the auxiliary device gateway has a built-in PID control strategy and communicates with a new generation of centralized control system and communication summary equipment, and can convey and feedback some specific instructions and information through the real-time temperature and load rate of the transformer, the communication summary equipment communicates with a communication receiving module in a wireless transmission manner, and the communication receiving module is embedded in the control device; The auxiliary equipment gateway transmits the received real-time information of the transformer temperature and load rate to the new generation centralized control system, realizes the manual data monitoring of the main transformer water spray device and determines whether to issue the start and stop device command, thereby realizing the remote control of the proportional solenoid valve (3); the auxiliary equipment gateway automatically starts the automatic control of the proportional solenoid valve (3) with the received transformer temperature and load rate, and the new generation centralized control system transmits the execution command to the auxiliary equipment gateway through the data network. When the remote control start command is issued and the auxiliary equipment gateway is turned on, the time lag period start up, After failure, the built-in PID control strategy is turned on, and the priority of remote control is set higher than automatic control. The PID control strategy is as follows: ; In the formula Indicates actual temperature With preset temperature The difference, is the integral term of the difference, which is used to eliminate the static error of the entire control process. It is the differential term of the error, which can respond to the change of the preset temperature value more quickly to achieve precise control. , and are the parameters of the PID control strategy. The values ​​of these three parameters determine the response speed and stability of the entire control process. , and The parameters are given by the manufacturer, where The output signal is transmitted to the execution module and then converted into a current signal to control the proportional solenoid valve; The proportional solenoid valve can be divided into four proportional opening positions according to the size of the given current signal, and the openings are 0, , and 1, set the preset temperature at the same time is 70℃, such as Figure 6 As shown, the specific working method is: A1. When the actual temperature When the temperature is lower than the preset temperature of 70°C, the proportional solenoid valve opening is set to 0, i.e. closed state; A2. When the actual temperature When the temperature is between 70℃ and 75℃, the proportional solenoid valve opening is set to ; A3. When the actual temperature When the temperature is between 75℃ and 80℃ (including 75℃), the proportional solenoid valve opening is set to ; A4. When the actual temperature Not less than 80℃, the proportional solenoid valve opening is set to 1; The built-in time lag function of the auxiliary equipment gateway can coordinate with the PID control strategy to set the load rate safety value The time delay period of the time delay function is 70%. Set to 30 minutes, the working mode is as follows: Since the transformer temperature is positively correlated with the transformer load rate, and the load rate increases first with the temperature increase, when the actual temperature When the temperature is lower than the preset temperature of 70℃, but the load rate is still higher than the safety value of 70%, a time delay period of 30 minutes is set. After 30 minutes, the load rate value is judged again, and the judgment is repeated in sequence until the load rate is less than 70%. Only then can the proportional solenoid valve be closed.

[0026] The communication receiving module adopts LORA433MHZ wireless communication technology, which is embedded in the control device TI AM335X. The control device has a built-in manual start function button. When the manual start is turned on, the manual start information is transmitted to the auxiliary device gateway through communication. The PID control strategy is closed at this time, and then the proportional opening gear of the proportional solenoid valve can be manually adjusted through the control panel of the control device. When the PID control strategy cannot effectively control the specific working mode of the proportional solenoid valve, the flexibility of control is increased. After the period, the PID control strategy is turned on again and the relevant control recovers automatically.

Claims

1. A transformer temperature reduction control device, characterized in that: It includes an electrical control module and a water circuit module. The electrical control module includes a station-side monitoring background that collects real-time information of the transformer. The station-side monitoring background is connected to the auxiliary equipment gateway in a read-only manner. The auxiliary equipment gateway executes the PID control strategy. The auxiliary equipment gateway is connected to the centralized control system and the communication summary equipment in communication, and the communication summary equipment is connected to the communication receiving module in communication in a wireless transmission mode; the water circuit module comprises a proportional solenoid valve (3), the proportional solenoid valve (3) is connected in series with the inspection valve (6) and then connected in parallel with the manual valve (5), the water inlet side of the manual valve (5) is connected with a flow meter (4), the water inlet side of the flow meter (4) is connected to the entire water circuit main pipeline (1), the main pipeline (1) is connected to two branch pipelines with the same arrangement, the two branch pipelines are terminated with spray pipes (2), and the two spray pipes (2) respectively perform water cooling auxiliary cooling on the 1# main transformer and the 2# main transformer.

2. The water spray arrangement method of a transformer temperature reduction control device according to claim 1, characterized in that: The auxiliary equipment gateway transmits the received real-time information of the transformer temperature and load rate to the new generation centralized control system, performs manual data monitoring of the main transformer water spray device and determines whether to issue a command to start and stop the device, thereby remotely controlling the proportional solenoid valve (3); the auxiliary equipment gateway automatically starts the automatic control of the proportional solenoid valve (3) based on the received transformer temperature and load rate; the new generation centralized control system transmits the execution command to the auxiliary equipment gateway through the data network. When the remote control start command is issued and the auxiliary equipment gateway is turned on, the time lag period start up, After failure, the built-in PID control strategy is turned on, and the priority of remote control is set higher than automatic control. The PID control strategy is as follows: ； In the formula Indicates actual temperature With preset temperature The difference, is the integral term of the difference, which is used to eliminate the static error of the entire control process. It is the differential term of the error, which can respond to the change of the preset temperature value more quickly to achieve precise control. , and It is the parameter of PID control strategy, which determines the response speed and stability of the whole control process; , and The parameters are given by the manufacturer, where The output signal is transmitted to the execution module and then converted into a current signal for controlling the proportional solenoid valve (3); The proportional solenoid valve (3) can be divided into four proportional opening positions according to the size of the given temperature signal, and the opening degrees are 0, , and 1, the specific working method is: When the actual temperature Less than the preset temperature When , the opening of the proportional solenoid valve (3) is set to 0, i.e. closed state; When the actual temperature exist ~( +5℃), the proportional solenoid valve (3) is set to open ; When the actual temperature exist( +5℃)~( +10℃), the proportional solenoid valve (3) is set to open ; When the actual temperature Not less than ( +10℃), the opening of the proportional solenoid valve (3) is set to 1.

3. The water spray arrangement method of a transformer temperature reduction control device according to claim 2, characterized in that: The auxiliary equipment gateway machine has an embedded time lag function that coordinates with the PID control strategy. The specific method is as follows: The transformer temperature is positively correlated with the transformer load factor, and the load factor increase takes precedence over the temperature increase. Less than the preset temperature When the load rate is still greater than the safety value , set the time delay period , Then judge the load rate again, and repeat the judgment until the load rate is less than the safe value. , at this time the proportional solenoid valve (3) is closed.

4. The water spray arrangement method of a transformer temperature reduction control device according to claim 3 is characterized in that: The control device has a built-in manual start function button. When the manual start is turned on, the manual start information is transmitted to the auxiliary device gateway through communication. The PID control strategy is turned off at this time. During this period, the PID control strategy is turned on again, and then the proportional opening gear of the proportional solenoid valve is manually adjusted by the control device, so as to manually control the proportional solenoid valve (3) to work when the PID control strategy cannot effectively control.

5. The water spray arrangement method of a transformer temperature reduction control device according to claim 4, characterized in that: The water circuit module is equipped with a spray pipe (2) and a proportional solenoid valve (3), and the arrangement is as follows: The spray pipe (2) is installed at the top position between adjacent heat sinks (9) of the transformer. The spray holes (10) provided on the spray pipe (2) are arranged such that the spacing between adjacent spray holes (10) is set to 1 cm. The angle of the water column ejected through the spray holes (10) relative to the heat sink (9) is set to 45 degrees. The proportional solenoid valve (3) is connected in series with the inspection valve (6) and then connected in parallel with the manual valve (5). The water inlet side of the manual valve (5) is connected with a flow meter (4) for detecting and controlling the water flow rate. A drain valve (8) is arranged at the lowest point of the pipeline on the water outlet side of the manual valve (5).

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