Transformer operation intelligent heat dissipation control system

Abstract

The application belongs to the technical field of transformer heat dissipation control, and specifically discloses a transformer operation intelligent heat dissipation control system, which comprises, in sequence, a heat dissipation device layout module, a temperature monitoring module, a hotspot identification module, a hotspot diffusion analysis module, an air flow control module and an execution feedback module. An infrared thermal imaging sensor array and a fan group are arranged in the transformer according to the distribution of heat sources. The infrared thermal imaging sensor array is used to collect the surface temperature distribution in real time, identify the hotspot area and its diffusion direction, and select the upstream, midstream and downstream fans to construct a directional relay cooling air flow chain through the time difference pulse and the rotational speed hierarchical control, so as to realize the forward-looking intervention on the current hotspot and potential diffusion path, and make the heat dissipation control have the local precise regulation and control ability with the dynamic evolution characteristic, thereby improving the heat dissipation efficiency and reducing the fan energy consumption.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of transformer heat dissipation control, and specifically discloses an intelligent heat dissipation control system for transformer operation. BACKGROUND

[0002] With the continuous improvement of the power system on the reliability of power supply, the transformer as the core equipment, its operation stability directly affects the safety of the power grid. A large amount of heat is generated in the operation of the transformer due to the loss, and if it cannot be dissipated in time and effectively, it will lead to local overheating, accelerate the insulation aging, and even cause failure. Therefore, the implementation of effective heat dissipation control is crucial to ensure its safe operation.

[0003] Compared with oil-immersed transformers, dry-type transformers have the advantages of good fireproof performance, convenient maintenance, strong environmental adaptability, etc., and are widely used in urban distribution networks and high-rise buildings and other scenes. However, due to the dependence on air cooling, it is easy to have the problem of excessive temperature rise under high load or poor ventilation conditions. Therefore, the cooling efficiency needs to be improved through heat dissipation control to ensure the safe operation and prolong the service life.

[0004] At present, the heat dissipation control of dry-type transformers mostly adopts the method of built-in fan combined with temperature sensor, for example, the Chinese invention patent with the publication number CN103594229A proposes a heat dissipation structure of dry-type transformer, which includes a fan, a temperature sensor, a temperature controller, an alarm and a proximity switch; by setting a temperature sensor between the high-voltage coil and the low-voltage coil, and combining the temperature controller to control the start and stop of the fan, the overall temperature of the transformer is monitored and cooled.

[0005] The above scheme mainly controls the start and stop of the fan according to the overall temperature threshold, and does not fully consider the local characteristics of the heat distribution inside the transformer. In actual operation, the temperature rise is often concentrated in a specific area, and the hot spot position will dynamically spread with the change of load and operating state. It is difficult to achieve accurate identification and directional intervention of local hot spots by relying only on global temperature control strategy, which leads to uneven cooling coverage, response lag, and thus reduces the heat dissipation efficiency. At the same time, the non-directional cooling method is easy to cause waste of cooling resources and increase the energy consumption of the fan. SUMMARY

[0006] In view of this, the present application aims to provide an intelligent heat dissipation control system for transformer operation, which realizes directional relay cooling control based on the heat propagation path through dynamic monitoring and diffusion direction identification of the hot spot area, and improves the heat dissipation efficiency and response ability of the local overheating area.

[0007] The purpose of the present application can be achieved by the following technical scheme: an intelligent heat dissipation control system for transformer operation, comprising: a heat dissipation device layout module: a micro infrared thermal imaging sensor array is arranged in the gap between the transformer high-voltage winding axial air duct and the core gap, and a fan group is arranged in the transformer according to the heat source distribution characteristics.

[0008] Temperature monitoring module: Real-time scanning of transformer surface temperature distribution using infrared thermal imaging sensor array, constructing spatial-time thermal gradient dataset.

[0009] Hot spot identification module: Spatial clustering processing of thermal gradient dataset, generating hot spot area identification results and marking hot spot area centroid coordinates.

[0010] Hot spot diffusion analysis module: Based on hot spot area centroid coordinates, radiation tracing to extract temperature gradient vector and temperature rise rate field to surrounding area, and fusion of temperature gradient vector and temperature rise rate field to predict hot spot diffusion direction.

[0011] Airflow control module: Selecting upstream fan, midstream fan and downstream fan according to hot spot diffusion direction, and performing time difference pulse and rotating speed grade control on three groups of fans to form directional relay cooling airflow chain.

[0012] Execution feedback module: Real-time monitoring of hot spot area temperature drop curve slope during airflow control process, and dynamic adjustment of fan group time interval and rotating speed grade.

[0013] Compared with the prior art, the beneficial effects of the present application are as follows: 1. The present application arranges infrared thermal imaging sensor array and fan group in the transformer according to heat source distribution, real-time collects surface temperature distribution, identifies hot spot area and its diffusion direction, and accordingly selects upstream, midstream and downstream fans to construct directional relay cooling airflow chain through time difference pulse and rotating speed control, realizes forward-looking intervention on current hot spot and potential diffusion path, and makes the heat dissipation control have local precise regulation and control ability with dynamic evolution characteristics, which improves heat dissipation efficiency while reducing fan energy consumption.

[0014] 2. The present application real-time collects heat dissipation effect of hot spot area during the time difference pulse and rotating speed control process based on upstream, midstream and downstream fans, and accordingly dynamically adjusts the start-stop time interval and rotating speed grade between fan groups to form a closed-loop feedback regulation mechanism, improves the response accuracy and adaptability of the cooling process, ensures that the heat dissipation strategy is optimized in real time with the evolution of hot spots, thereby improving the heat dissipation efficiency and enhancing the stability and intelligent level of system operation. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used for the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0016] Figure 1 The system composition schematic diagram in the present application.

[0017] Figure 2 Fig. 3 is a schematic diagram of a radial path around the centroid of a hotspot area in the present application.

[0018] Figure 3 Fig. 4 is an operation diagram of the time sequence difference pulse and speed gear control of the upstream fan, the midstream fan and the downstream fan corresponding to the diffusion direction of the hotspot in the present application. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0020] Referring to Figure 1 The present application proposes a transformer operation intelligent heat dissipation control system, which comprises heat dissipation device layout module, temperature monitoring module, hotspot identification module, hotspot diffusion analysis module, air flow control module and execution feedback module which are coupled in sequence, realizes closed-loop data flow from environment perception to dynamic regulation and control, and builds a complete heat dissipation control chain from state monitoring, analysis and decision to precise intervention.

[0021] The heat dissipation device layout module is used for laying a micro infrared thermal imaging sensor array at the axial air duct gap of the transformer high-voltage winding and the core gap, and laying a fan group in the transformer according to the heat source distribution characteristics.

[0022] It should be noted that the micro infrared thermal imaging sensor array is laid at the axial air duct gap of the transformer high-voltage winding and the core gap because these parts are key areas with local heat source concentration and significant temperature rise. The infrared thermal imaging sensor can realize continuous monitoring of non-contact surface temperature field, has the advantages of wide coverage, high spatial resolution and fast response speed compared with traditional point temperature sensors, can more comprehensively and accurately reflect the internal heat distribution state of the equipment, and improve the sensitivity and positioning accuracy of hotspot identification.

[0023] It needs to be supplemented that, in order to ensure the effective layout of the infrared thermal imaging sensor array at the key parts of the transformer, a mirror relay structure is used at the axial air duct gap of the high-voltage winding, and a 90° turning lens is used to realize temperature monitoring of the blind area of the winding inner surface; in the core gap area, a patch type sensor is deployed, and a high-temperature resistant insulating ceramic layer is covered on the surface. The above structure design aims to ensure that the sensor can accurately capture the heat distribution information of the hidden area, and at the same time meet the electrical insulation and operation reliability in high-temperature environment, improve the overall temperature measurement accuracy and system safety.

[0024] In the preferred implementation of the above scheme, the fan group is arranged according to the heat source distribution characteristics in the transformer as follows: independent fan columns are arranged in the high-voltage winding area of the transformer along the axial direction for each phase, and the spacing between the fans in the column is adapted to the width of the air duct.

[0025] It should be understood that the width of the air duct refers to the actual width of the channel inside the transformer for guiding the flow of cooling air, which is usually determined by the design structure of the transformer.

[0026] The above-mentioned arrangement of fans in the high-voltage winding area along the axial direction and the adaptation of the spacing between the fans to the width of the air duct is because if the spacing between the fans is too large or too small, it may cause uneven airflow, resulting in local vortex or dead zones, affecting the heat dissipation effect. The spacing between the fans adapted to the width of the air duct can ensure uniform distribution of airflow across the entire air duct cross-section, avoiding airflow discontinuity or dead angles, thereby improving overall heat dissipation efficiency.

[0027] In the transformer core joint area, the fan units are installed in a diagonal cross arrangement, with the fan outlet axis forming an oblique angle with the core joint plane. The recommended angle range is 30°-60°.

[0028] In the above-mentioned diagonal cross arrangement of fans in the core joint area, the cross-perturbed airflow is formed to enhance the cooling effect of the local hot spots between the core laminations, while avoiding the increase of magnetic hysteresis loss caused by direct airflow.

[0029] A convection fan group with bidirectional reversing function is arranged at the bottom and top of the transformer respectively.

[0030] In the above-mentioned arrangement of convection fan groups with bidirectional reversing function at the bottom and top of the transformer, a driven convection circulation system in the vertical direction is constructed. The bottom fan can guide cold air into the interior of the device, and the top fan can cooperate to exhaust high-temperature gas, forming an upper and lower linkage hot air replacement mechanism, effectively preventing the occurrence of local heat accumulation.

[0031] Through the above-mentioned three differentiated fan arrangement methods, targeted cooling layout for the high-voltage winding, core joint, and overall cavity in the transformer is achieved, and an intelligent fan group heat dissipation network with spatial adaptability and dynamic response capability is constructed.

[0032] It should be noted that the dry-type transformer usually adopts air natural convection or forced air cooling for heat dissipation, and the structure is provided with cooling channels such as axial air duct, winding gap and core gap, which provides a feasible space for air flow organization and fan arrangement. Especially in the high-voltage winding area, the low-voltage winding area and the core around, there is a regular geometric space, which is suitable for arranging small and modular fan columns along the axial or radial direction. At present, there are micro DC fans, brushless fans and low-power axial flow fans, which have the characteristics of small size, low noise and high efficiency, and are suitable for the compact environment inside the transformer. The fan can be installed in a modular way and embedded in the air duct or integrated into the support structure without affecting the original electrical performance. Therefore, the dry-type transformer has the physical space and technical feasibility to arrange the fan group.

[0033] The temperature monitoring module is used to scan the surface temperature distribution of the transformer in real time with an infrared thermal imaging sensor array to construct a space-time thermal gradient data set.

[0034] Optionally, the specific implementation of the above module includes the following: during the operation of the transformer, a non-contact thermal field scanning of the surface of the transformer is performed by using an infrared thermal imaging sensor array to obtain continuous two-dimensional thermal images, wherein each pixel point in the thermal image corresponds to the surface temperature value of the measured area.

[0035] It should be noted that in order to ensure the consistency and accuracy of the data, all infrared thermal imaging sensors should collect data synchronously.

[0036] A three-dimensional space rectangular coordinate system is established based on the structure of the transformer body, and the pixel points in the two-dimensional thermal image are mapped into the coordinate system to form a temperature field distribution graph with spatial positioning information, thereby realizing the visualization and spatial marking of the temperature distribution of the key areas of the transformer.

[0037] In the specific implementation of the above scheme, the three-dimensional space rectangular coordinate system is established as follows:

[0038] The origin of the coordinate system is set at the geometric center position of the transformer body, which is usually the intersection of the high and low voltage winding center axes or the midpoint of the core column cross section. This setting helps to unify the spatial positioning reference of each part and facilitates the subsequent spatial mapping of thermal field data.

[0039] Define the three-axis directions: the X-axis is along the axial direction of the high-voltage winding of the transformer, i.e. the extension direction of the cooling air duct. The Y-axis is along the circumferential direction of the winding, which is used to represent the temperature distribution of different phases or angular positions of the winding; the Z-axis is perpendicular to the winding plane and points to the outer surface of the transformer, which is used to represent the height or interlayer position.

[0040] The temperature field distribution graphs corresponding to multiple time sampling points are stacked in time sequence to construct a space-time thermal gradient data set containing spatial position and time dimension, which is used to describe the dynamic evolution process of the temperature of each key area with time and space.

[0041] The hotspot recognition module is used for spatial clustering processing on the thermal gradient data set, generating a hotspot area recognition result and marking a hotspot area center coordinate.

[0042] As an implementable manner of the present application, the specific implementation process of the above module is as follows: for each pixel point in the space-time thermal gradient data set corresponding to the current time sampling point, the temperature difference between the pixel point and the surrounding adjacent pixel points is calculated, and a preset temperature difference threshold is applied to screen out the pixel points with the temperature difference exceeding the threshold as potential heat island candidate points.

[0043] In the above, the adjacent pixel points of each pixel point are defined as the pixel set directly adjacent thereto.

[0044] It should be understood that the surface temperature of the transformer changes smoothly based on the basic law of heat conduction under normal operating conditions; when local abnormal heating occurs, a significant temperature jump will be formed. Using the temperature difference between adjacent pixel points as a criterion can effectively capture this local thermal disturbance.

[0045] In the above, the temperature difference threshold is essentially a quantification of the temperature change rate between adjacent pixels. When the temperature difference between a certain point and its neighborhood exceeds the threshold, it indicates that there is a significant temperature jump in this region, which may be caused by local heat concentration or limited heat conduction, and has the risk of becoming a hotspot.

[0046] Specifically, the temperature difference threshold can be set according to the thermal performance parameters of the internal materials of the transformer, for example, the maximum local temperature difference limit value allowed can be obtained from the technical manual according to the material specifications, and the threshold can be set to a certain proportion slightly lower than this limit value. This setting method reflects the comprehensive consideration of the thermal stability and insulation safety margin of the material, aiming to identify the possible local overheating trend in advance on the premise of ensuring the safe operation of the equipment, to realize early warning and intervention of the hotspot.

[0047] A clustering algorithm is used to perform spatial aggregation processing on all heat island candidate points, merging them into high-temperature regions with spatial continuity.

[0048] It should be understood that a heat island region is often not an isolated point, but a high-temperature zone with spatial continuity. The clustering algorithm can automatically merge adjacent pixel points with similar temperatures to form a structured high-temperature region.

[0049] The high-temperature region formed by the current time sampling point is spatially overlapped with the high-temperature region identified by the next time sampling point, and a spatiotemporal coincidence degree index of the high-temperature region is obtained by calculating the intersection and union ratio between the two regions.

[0050] It needs to be understood that after identifying the high-temperature region based on the current time sampling point, it is not directly determined as a hotspot region. In order to improve the stability and dynamic tracking ability of hotspot identification, the concept of time coincidence degree is introduced to evaluate the spatial consistency and persistence characteristics of the high-temperature region in the time sequence by calculating the spatial intersection ratio of the high-temperature region at adjacent time sampling points. This method can effectively distinguish between false high-temperature regions caused by transient temperature fluctuations and real hotspot regions with persistent evolution trends, thereby avoiding misjudgment and improving the accuracy and robustness of hotspot identification.

[0051] The high-temperature space-time coincidence degree is compared with a preset hotspot persistence judgment threshold value. If the coincidence degree reaches or exceeds the threshold value, it is determined that the high-temperature region has persistent heating characteristics, and the high-temperature region at the next time sampling point is judged as a hotspot region.

[0052] The hotspot persistence judgment threshold value is essentially a constraint condition for the spatial coincidence degree of the high-temperature region between adjacent time sampling points, and reflects the basis for distinguishing whether the local temperature anomaly is persistent or non-transient. If the high-temperature region maintains a high spatial coincidence degree at consecutive time points, it indicates that it has a clear development trend and heat accumulation effect. Conversely, if the coincidence degree is low, it may be caused by transient disturbance or measurement noise and should not be considered as a real hotspot.

[0053] Specifically, the hotspot persistence judgment threshold value can be set based on the geometric structure and material thermal conductivity of the transformer to establish a heat diffusion model, simulate the spatial expansion process of the hotspot region over time, calculate the spatial coincidence degree at different times, and set a reasonable threshold value based on the simulation results to match the evolution speed and range changes of the actual hotspot.

[0054] The spatial coordinates of all pixel points in the identified hotspot region are weighted and averaged using the corresponding temperature values as weights to obtain the centroid coordinates of the hotspot in the three-dimensional space coordinate system.

[0055] In the above, the temperature value is used as the weight to linearly weight and average the spatial coordinates of the hotspot region, which can more accurately reflect the thermal center of the high-temperature region rather than the geometric center. From a mathematical point of view, this method is equivalent to performing weighted expectation estimation on the normalized temperature field in the spatial domain, which reflects the physically meaningful heat distribution barycenter and more truly reflects the core position of local heat accumulation.

[0056] The hotspot diffusion analysis module is configured to radiate and track the surrounding area based on the centroid coordinates of the hotspot region to extract a temperature gradient vector and a temperature rise rate field, and fuse the temperature gradient vector and the temperature rise rate field to predict the diffusion direction of the hotspot.

[0057] Preferably, the temperature gradient vector and the temperature rise rate field are extracted by radiation tracing based on the hotspot region centroid coordinates as follows: taking the centroid coordinates of the hotspot region as the center point, performing temperature sampling on each pixel point along multiple radially distributed radial paths around the centroid in the two-dimensional temperature field, and extending the sampling path in each direction outward from the hotspot core to continuously track the boundary position where the temperature value drops to the ambient background temperature, thereby defining the spatial influence range of the local thermal disturbance.

[0058] It should be noted that after identifying the hotspot region, it is considered that it is not static but has dynamic diffusion characteristics. The heat of the hotspot region as a local heat source will diffuse to the surrounding medium in the form of a spherical wave, which is a radial propagation in two-dimensional space. Therefore, sampling along multiple radial directions can effectively capture the heat energy distribution trend. This method helps to predict the main propagation path and potential impact area of the hotspot in the future, thereby identifying the possible heat energy migration direction and new hotspot formation position in advance, providing forward-looking and targeted decision support for heat dissipation control strategies.

[0059] It should be understood that the above-mentioned set of radial lines distributed around the centroid of the hotspot is used to simulate the possible propagation path of heat. Specifically, the radial paths around the centroid of the hotspot region are shown in FIG. 2. Figure 2

[0060] It should be noted that the ambient background level refers to the normal operating temperature away from the hotspot region as a reference benchmark for judging local abnormal temperature rise.

[0061] For each direction, the maximum temperature difference value on the sampling path is extracted by comparing the collected temperature values with the ambient background temperature. The maximum temperature difference reflects the strength of the local thermal disturbance in that direction and its potential expansion trend.

[0062] The direction corresponding to the maximum temperature difference value in all directions is defined as the temperature gradient main direction at the current time, and the temperature gradient vector is constructed by combining the unit vector of the direction and the maximum temperature difference value.

[0063] The above-mentioned temperature gradient vector is constructed by combining the unit direction vector corresponding to the temperature gradient main direction and the corresponding maximum temperature difference value, which has directional and amplitude information, and is used to represent the dominant trend of heat conduction from the hotspot region to the external environment.

[0064] ​It needs to be understood that according to the basic principle of thermodynamics, heat tends to propagate along the path with the smallest thermal resistance in the medium; and the maximum temperature difference direction in the local hot spot area usually reflects the direction of the most severe temperature change in the area, which is taken as the main direction of the temperature gradient, which characterizes the most active expansion trend of the current hot spot, and thus can be used as the main prediction direction of the hot spot diffusion path, which has a high probability of being consistent with the actual heat propagation direction.

[0065] The temperature rise rate of the temperature values at the same spatial position on the sampling path in each direction is calculated for the thermal gradient data set at two consecutive time sampling points under the same spatial structure framework. The temperature rise rate is the temperature change rate of the same spatial position, i.e., the pixel point, at two time sampling points, i.e., the temperature difference between the later time sampling point and the earlier time sampling point divided by the time interval of the two time sampling points.

[0066] The area where the temperature rise rate exceeds the set temperature rise rate determination limit value is marked as a hot spot expansion area, and a temperature rise rate field map around the current hot spot area is generated accordingly. The temperature rise rate field map not only contains the current hot spot area but also the hot spot expansion area around the current hot spot area, which describes the dynamic evolution characteristics of the hot spot in space.

[0067] The temperature rise rate determination limit value is essentially a constraint on the temperature rise speed per unit time, which can distinguish between normal temperature rise fluctuations and local thermal disturbances with a development trend. When the temperature rise rate of a certain area exceeds the limit value, it indicates that it may be an active area on the hot spot diffusion path and has the potential to become a new hot spot, and thus is marked as a hot spot expansion area. By setting the temperature rise rate limit value, the area that will rise in temperature can be identified in advance, and its spatial orientation relative to the current hot spot can provide a reference for hot spot diffusion direction prediction.

[0068] Specifically, the temperature rise rate determination limit value can be determined by analyzing the historical temperature data of the transformer under various load conditions and environmental conditions. By statistically analyzing the typical temperature rise rates recorded in each area, the average temperature rise rate and its standard deviation can be calculated, and the limit value can be set as the average value plus several times the standard deviation, so as to cover the temperature rise fluctuation range under normal operating conditions. When the actual temperature rise rate of a certain area exceeds this preset limit value, it indicates that the temperature rise speed of the area has exceeded the fluctuation range expected by the conventional operation, showing an abnormal acceleration trend. This usually indicates that the area may be experiencing a thermal disturbance different from the normal working state in the past.

[0069] The application provides a prediction reference for heat propagation direction by constructing a temperature gradient vector at a current time point when predicting a diffusion direction based on a hotspot area. Meanwhile, a time dimension analysis mechanism is introduced to construct a temperature rise rate field, which provides a trend prediction reference for a dynamic evolution process of the hotspot, uses the time dimension to enhance the dynamic response capability of identification, avoids static misjudgment, and forms a closed-loop hotspot diffusion trend analysis mechanism.

[0070] Further, the temperature gradient vector and the temperature rise rate field are fused to predict the hotspot diffusion direction, and the following process is used: comparing the temperature rise rate of each hotspot expansion area in the temperature rise rate field map, extracting the hotspot expansion area with the maximum temperature rise rate as the dominant expansion area, and the area represents the most developing front of thermal disturbance in the current hotspot evolution process.

[0071] The connection vector direction between the two is determined according to the spatial pointing relationship between the center of the hotspot area and the center of the dominant expansion area, and the direction is defined as the temperature rise rate field expansion direction.

[0072] The temperature gradient vector and the temperature rise rate field expansion direction are vector superimposed, wherein the temperature gradient vector represents the main spatial direction of the heat energy release of the hotspot at the current time, and the temperature rise rate field expansion direction represents the dynamic evolution path, which embodies the fusion of static heat conduction and dynamic expansion trend.

[0073] If the two vectors are consistent or approximately in the same direction, it indicates that the static heat conduction direction and the dynamic expansion trend are coordinated and unified, and the output combined vector is the hotspot diffusion direction.

[0074] When the two vectors are consistent or approximately in the same direction, it is specifically embodied that the included angle between the two vectors is less than 90°, and when the two vectors are opposite, it is specifically embodied that the included angle between the two vectors is greater than 90°.

[0075] When the two vectors are opposite, it indicates that the heat energy propagation direction of the current hotspot is deviating, and the temperature rise rate field expansion direction is output as the hotspot diffusion direction, because it can better reflect the developing thermal disturbance trend.

[0076] The airflow control module is used to select the upstream fan, the middlestream fan group, and the downstream fan according to the hotspot diffusion direction, and perform time difference pulse and rotating speed level control on the three fan groups to form a directional relay cooling airflow chain.

[0077] Optionally, selecting the upstream fan, the middlestream fan, and the downstream fan according to the hotspot diffusion direction includes the following: the upstream fan is a fan located in the opposite direction of the hotspot diffusion direction and having a spatial distance greater than a preset safety distance from the current hotspot area.

[0078] The middlestream fan is located in the spatial coverage range of the current hotspot area.

[0079] Downstream fan: a fan located in the positive direction of the hotspot diffusion direction and with a spatial distance between its installation position and the hotspot expansion area less than the set pre-cooling radius.

[0080] According to the supplementary description of the above scheme, the safety distance refers to the minimum spatial interval that should be maintained between the upstream fan and the current hotspot area. This distance should be greater than the range that can be directly affected by thermal disturbance, to ensure that the air introduced by the upstream fan is still in a relatively low temperature state and is not disturbed by the thermal effects of the hotspot.

[0081] The pre-cooling radius refers to the maximum spatial distance that can be effectively covered by the downstream fan group when it is arranged on the hotspot diffusion path. The area within this range is considered to be a potential hot area that may be affected by the hotspot in the future, and air flow guidance and temperature regulation need to be performed in advance. Specifically, by identifying the thermal influence prediction range of the forward area in the hotspot diffusion direction, deploying the downstream fan group in this area can achieve pre-cooling intervention for the area that will soon be heated, and establish an air flow channel in advance to prevent heat accumulation and improve system response speed.

[0082] It should be understood that the upstream fan is used to introduce cold air that is not affected by thermal disturbance, to ensure that the air sucked by the upstream fan is not heated, providing stable initial air flow conditions for subsequent cooling process. The midstream fan directly acts on the hotspot body or its thermal influence core area, and is used to implement high-intensity local cooling intervention to effectively suppress the temperature rising trend. The downstream fan is used to guide the hot air out or to perform early cooling intervention on the potential heating area to prevent heat accumulation.

[0083] The above selection of upstream fan, midstream fan and downstream fan according to the hotspot diffusion direction can construct a complete cooling chain from the introduction of cold air to the cooling of hotspot core area to the discharge of hot air, thereby realizing directional relay cooling control of the hotspot.

[0084] Referring to Figure 3 As shown, further optionally, the timing difference pulse and speed gear step control of the three groups of fans is implemented as follows: the upstream fan is started first, the midstream fan is started after a delay time length of the upstream fan, and the downstream fan is started after a delay time length of the midstream fan.

[0085] The delay time length between the upstream fan and the midstream fan can be estimated according to the actual length of the internal air duct of the transformer and the air supply speed of the upstream fan, to determine the time required for the transmission of cold air from the upstream area to the midstream area. For the delay time length between the midstream fan and the downstream fan, it can also be calculated based on the geometric size of the midstream-to-downstream section air duct and the average flow speed of the air flow in this area, to ensure that the air after heat exchange still has sufficient cooling capacity when entering the downstream area, thereby realizing the orderly connection of the air flow and the continuity of the cooling process.

[0086] It needs to be understood that the application of the above operation is that the control system first triggers the start command of the upstream fan under the preset condition to guide the cold air into the system and establish the initial cooling air flow. Subsequently, a start signal is sent to the middle fan after a set time delay after the start of the upstream fan, so that it carries out concentrated cooling intervention on the hot core area on the basis that the cold air flow has been initially established. Further, a time delay control system is introduced after the start of the middle fan to output a start command to the downstream fan, ensuring that it intervenes in operation when the hot air starts to move to the diffusion path, so as to effectively guide the hot air out and maintain the overall air flow circulation. Through the above pulse start control with time difference, the coordinated cooperation and air flow relay effect between the fan groups are realized, and the response capability and energy efficiency utilization rate of the cooling system are improved.

[0087] The high-speed gear is adopted for the upstream fan to generate high-speed laminar flow to resist the heat diffusion trend, the medium-speed gear is adopted for the middle fan to maintain the stable coverage of the vortex ring air mass, and the low-speed gear is adopted for the downstream fan to generate continuous negative pressure to adsorb the overflow heat.

[0088] The execution feedback module is used for monitoring the temperature drop curve slope of the hot spot area in real time in the air flow control process and dynamically adjusting the time interval and speed gear of the fan group.

[0089] As a specific implementation of the above module, the temperature data of the hot spot area is collected in real time in the air flow control process to construct the temperature drop curve changing with time.

[0090] The curve slope of the current time window and the current temperature of the hot spot area are obtained from the drawn temperature drop curve based on the set time window, and are compared with the target cooling rate and the environmental background temperature, respectively. If the current temperature of the hot spot area has not dropped to the environmental background temperature and the curve slope of the current time window is lower than the target cooling rate, it indicates that the current cooling response is insufficient, and the fan linkage rhythm needs to be accelerated to enhance the cold air flow. At this time, the time delay pulse delay between the upstream fan, the middle fan and the downstream fan is shortened step by step until the minimum allowed value is reached, so as to improve the response speed and cooperation efficiency of the cooling air flow.

[0091] It needs to be noted that the temperature drop curve reflects the actual intervention effect of the current cooling strategy on the local heat field, and the slope of the curve represents the cooling rate per unit time, which is the core dynamic index for evaluating the response capability and efficiency of the cooling system. The temperature of the current hot spot area reflects the actual output result of the cooling action. Taking the two as the basis for coordinated regulation, double closed-loop control of the cooling process can be realized: on the one hand, the slope is used to judge whether the cooling dynamics meets the expectation, and on the other hand, the temperature is used to judge whether the cooling target is gradually approaching. This comprehensive regulation mechanism combining dynamic trend and static result helps to accurately identify the cooling efficiency deviation and dynamically optimize the fan group operation strategy, so as to improve the responsiveness, stability and energy efficiency level of the overall heat dissipation system.

[0092] In particular, the target cooling rate described in the above scheme characterizes the temperature drop speed expected to be achieved by the cooling system per unit time, which is usually set according to the thermal capacity, thermal conductivity and insulation grade of the transformer body material and other physical parameters. The rate can be obtained from the technical specifications of the specific transformer model, from its product specification or technical manual, to prevent local temperature rise accumulation or insulation degradation caused by slow cooling.

[0093] In further embodiments, the time difference pulse delay between the upstream, midstream and downstream fans can be adjusted step by step through a preset multi-stage delay strategy. For example, the initial delay levels are set to be 5 seconds, 3 seconds, 1 second, etc. When the system detects that the temperature drop curve slope is lower than the target cooling rate, it switches to a shorter delay configuration in the preset order to improve the air flow coordination efficiency and cooling response speed. After each delay adjustment, temperature data is continuously collected and the slope of the temperature drop curve is recalculated, combined with the current hot spot area temperature, and compared with the target cooling rate to determine whether the expected cooling effect is met. If the set performance indicators have not been met, the system continues to switch to the next shorter delay until the minimum allowed delay threshold is reached, thereby realizing a closed-loop cooling control process with dynamic optimization.

[0094] If the curve slope of the current time window reaches or is higher than the target cooling rate, it indicates that the current cooling strategy is effective, and the system enters a stable maintenance stage. At this time, the maintenance time is tracked and compared with the set time. If the maintenance time has not reached the set time, the upstream fan remains in high speed, the midstream fan speeds up to sub-high speed, and the downstream fan increases to medium speed to enhance the hot air exhaust capacity. If the maintenance time reaches the set time, the current fan start-stop timing and speed configuration remain unchanged until the hot spot area temperature drops to the ambient background temperature.

[0095] The set time described above reflects the minimum time requirement for the cooling system to maintain an effective cooling state after reaching the target cooling rate, which is used to determine whether the current cooling control strategy has achieved stable suppression of the local thermal field, preventing false judgments or premature exit from the high-efficiency cooling mode caused by transient temperature fluctuations. Its physical meaning is that only when the transformer runs at the target cooling rate for a sufficient time can it be confirmed that the heat accumulation process of the hot spot area has been effectively alleviated and the thermal equilibrium tends to be stable. Specifically, the set time can be statistically analyzed based on historical operation data, and the typical cooling period of the effective cooling process under the same or similar working conditions is selected, with the mean value or slightly higher than the mean value as the reference, thereby improving the adaptability and robustness of the control strategy.

[0096] If the current hotspot temperature drops to the ambient background temperature, indicating that the local overheating problem has been resolved, the upstream, midstream and downstream fans are uniformly adjusted to medium speed operation and maintained for a set period of time, ensuring uniformity of the internal thermal field and preventing residual heat backflow.

[0097] The above-described embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, the above-described embodiments can be implemented in whole or in part in the form of a computer program product.

[0098] Those of ordinary skill in the art can be aware that, with reference to the examples described in the embodiments disclosed in the present document, the modules and algorithm steps of each example can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether the functions are performed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present application.

[0099] In addition, each functional module in each embodiment of the present application can be integrated into one processing module, or each module can exist physically independently, or two or more modules can be integrated into one module.

[0100] The above description is merely specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0101] Finally, the above description is merely preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An intelligent heat dissipation control system for transformer operation, characterized in that: include: Heat dissipation equipment layout module: A micro infrared thermal imaging sensor array is placed in the axial air duct gaps of the transformer's high-voltage windings and the cracks in the iron core. At the same time, fan groups are placed inside the transformer according to the heat source distribution characteristics. Temperature monitoring module: uses an infrared thermal imaging sensor array to scan the transformer surface temperature distribution in real time and construct a spatial-temporal thermal gradient dataset; Hotspot identification module: performs spatial clustering on the thermal gradient dataset, generates hotspot area identification results and marks the centroid coordinates of the hotspot area; Hotspot diffusion analysis module: Based on the centroid coordinates of the hotspot area, radiation tracing is performed to the surrounding area to extract the temperature gradient vector and temperature rise rate field, and the temperature gradient vector and temperature rise rate field are integrated to predict the hotspot diffusion direction; Airflow control module: Selects upstream, midstream, and downstream fans based on the hotspot diffusion direction, and performs timing difference pulse and speed gear graded control on the three groups of fans to form a directional relay cooling airflow chain; Execution feedback module: During the airflow control process, the slope of the temperature drop curve in the hotspot area is monitored in real time, and the timing interval and speed level of the fan group are dynamically adjusted; The speed gear stage control is implemented as follows: Use high speed gear for upstream fans, medium speed gear for midstream fans, and low speed gear for downstream fans; The specific implementation process of the execution feedback module is as follows: During the airflow control process, the temperature data of the hot spot area is collected in real time to construct the temperature drop curve over time; Based on the set time window, the slope of the curve in the current time window and the current hotspot area temperature are obtained from the drawn temperature drop curve, and compared with the target cooling rate and ambient background temperature respectively. If the current hotspot area temperature has not dropped to the ambient background temperature and the slope of the curve in the current time window is lower than the target cooling rate, the timing difference pulse delay length between the upstream, midstream and downstream fans is gradually shortened until it reaches the minimum allowable value; If the slope of the curve in the current time window reaches or exceeds the target cooling rate, the maintenance duration is tracked and compared with the set duration. If the maintenance duration does not reach the set duration, the upstream fan is kept at high speed, the midstream fan is increased to sub-high speed, and the downstream fan is increased to medium speed. If the maintenance duration reaches the set duration, the current fan start-stop sequence and speed configuration are maintained unchanged until the temperature in the hotspot area drops to the ambient background temperature. If the current hotspot temperature drops to the ambient background temperature, the upstream, midstream and downstream fans will be uniformly adjusted to medium speed and maintained for the set time.

2. The intelligent heat dissipation control system for transformer operation according to claim 1, characterized in that: The fan group is arranged in the transformer according to the heat source distribution characteristics as follows: An independent fan row is set up for each phase along the axial direction in the high-voltage winding area of ​​the transformer, and the fan spacing within the row is adapted to the width of the air duct; The fans are installed in an oblique cross arrangement in the transformer core joint area, with the fan outlet axis forming an oblique angle with the core joint plane; Convection fan groups with bidirectional reversing functions are respectively arranged at the bottom and top of the transformer.

3. The intelligent heat dissipation control system for transformer operation according to claim 1, characterized in that: The temperature monitoring module includes the following: During the operation of the transformer, an infrared thermal imaging sensor array is used to perform non-contact thermal field scanning on the transformer surface to obtain continuous two-dimensional thermal images, where each pixel in the thermal image corresponds to the surface temperature value of the measured area; A three-dimensional rectangular coordinate system is established based on the transformer structure, and the pixels in the two-dimensional thermal image are mapped to the coordinate system to form a temperature field distribution map with spatial positioning information; The temperature field distribution maps corresponding to multiple time sampling points are superimposed in time series to construct a space-time thermal gradient dataset containing spatial position and time dimensions.

4. The intelligent heat dissipation control system for transformer operation according to claim 3, characterized in that: The specific contents of the hotspot identification module are as follows: For each pixel in the space-time thermal gradient dataset corresponding to the current sampling point, the temperature difference between it and its surrounding pixels is calculated. A preset temperature difference threshold is applied to select pixels with temperature differences exceeding the threshold as potential heat island candidate points. A clustering algorithm is used to spatially aggregate all candidate heat island points and merge them into high-temperature areas with spatial continuity. The spatial overlap of the high-temperature area formed by the current sampling point and the high-temperature area identified by the next sampling point is analyzed, and the spatiotemporal overlap index of the high-temperature area is obtained by calculating the ratio of the intersection and union between the two areas; The high-temperature spatiotemporal coincidence is compared with the preset hotspot persistence judgment critical value. If the coincidence reaches or exceeds the critical value, the high-temperature area at the next time sampling point is judged as a hotspot area. The spatial coordinates of all pixels in the identified hotspot area are weighted averaged using the corresponding temperature value as the weight to obtain the centroid coordinates of the hotspot in the three-dimensional space coordinate system.

5. The intelligent heat dissipation control system for transformer operation according to claim 1, characterized in that: The following operation is performed to extract the temperature gradient vector and the temperature rise rate field based on the radiation tracing of the hotspot area centroid coordinates to the surrounding area: Taking the centroid coordinates of the hotspot area as the center point, the temperature is sampled pixel by pixel along multiple radial paths around the centroid in the two-dimensional temperature field. The sampling paths in each direction extend outward from the hotspot core and continue to track until the temperature value drops to the boundary position of the ambient background temperature. For each direction, the maximum temperature difference value relative to the ambient background on the sampling path is extracted by comparing the collected temperature value with the ambient background temperature; The direction corresponding to the maximum temperature difference in all directions is defined as the main direction of the temperature gradient at the current moment, and the temperature gradient vector is constructed by combining the unit vector of this direction and the maximum temperature difference; For the thermal gradient data set at two consecutive time sampling points, the temperature rise rate is calculated for the temperature value at the same spatial position on the sampling path in each direction under the same spatial structure framework; The area where the temperature rise rate exceeds the set temperature rise rate judgment limit is marked as the hotspot expansion area, and a temperature rise rate field map around the current hotspot area is generated based on this.

6. The intelligent heat dissipation control system for transformer operation according to claim 5, characterized in that: The process of fusion temperature gradient vector and temperature rise rate field to predict hot spot diffusion direction is as follows: Compare the temperature rise rates of each hotspot expansion area in the temperature rise rate field map, and extract the hotspot expansion area with the maximum temperature rise rate as the dominant expansion area; According to the spatial directional relationship between the center of mass of the hot spot area and the center of mass of the dominant expansion area, the direction of the connection vector between the two is determined, and this direction is defined as the expansion direction of the temperature rise rate field; Perform vector superposition of the temperature gradient vector and the expansion direction of the temperature rise rate field; If the two vectors are consistent or approximately in the same direction, the output composite vector is the hotspot diffusion direction; When the two vectors are in opposite directions, the expansion direction of the output temperature rise rate field is the hot spot diffusion direction.

7. The intelligent heat dissipation control system for transformer operation according to claim 1, characterized in that: The selection of upstream fans, midstream fans, and downstream fans according to the hotspot diffusion direction includes the following: Upstream fans: fans located in the opposite direction of the hotspot diffusion direction and whose spatial distance from the current hotspot area is greater than the preset safety distance; Midstream fans: located within the spatial coverage of the current hotspot area; Downstream fan: A fan located in the positive direction of the hotspot diffusion direction and whose installation position and the spatial distance between the hotspot expansion area are less than the set pre-cooling radius.

8. The intelligent heat dissipation control system for transformer operation according to claim 1, characterized in that: The timing difference pulse is controlled in the following hierarchical manner: The upstream fan starts first, the midstream fan starts after the delay time of the upstream fan start, and the downstream fan starts after the delay time of the midstream fan start.

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