Thermal Management Method and System for Electric Traction Equipment

Abstract

The present invention relates to the technical field of electric stretching equipment, and provides a thermal management method and system for an electric stretching equipment. The operating conditions of the electric stretching equipment include a traction condition and a tension condition. This thermal management method is used to manage the battery module that powers the electric stretching equipment, and it includes determining the operating conditions of the electric stretching equipment; when the traction condition is triggered, switching to a first heat dissipation mode; wherein, the maximum heat dissipation power Q1 of the first heat dissipation mode satisfies: Q1 ≥ 1.5 × P*; P* represents the maximum heat generation power of the battery module under the traction condition; when the tension condition is triggered, switching to a second heat dissipation mode; wherein, the maximum heat dissipation power Q2 of the second heat dissipation mode satisfies: Q2 = (0.3 - 0.5) × Q1. The thermal management method and system for the electric stretching equipment of the present invention eliminate the hysteresis of temperature feedback through the operating condition prediction and active heat dissipation mode switching mechanism, and improve the efficiency and effectiveness of thermal management.

Description

Technical Field

[0001] The present invention relates to the technical field of electric tensioning equipment, and in particular to a thermal management method and system for electric tensioning equipment. Background Art

[0002] The electric tensioning equipment is the core equipment for overhead line stringing construction of transmission lines, and its power system is powered by a battery module. Due to the significant difference in the load characteristics of the equipment under the traction condition (actively outputting power) and the tension condition (passively maintaining tension), there is an order-of-magnitude difference in the heat generation power of the battery module under different working conditions. For example, during the traction condition, the large current discharge of the battery causes a sharp increase in heat generation, while during the tension condition, the battery is in a low-power maintenance state with low heat generation.

[0003] For battery thermal management, a heat dissipation control strategy based on temperature feedback is usually adopted. By arranging temperature sensors in the battery module, the battery temperature is monitored in real time, and the heat dissipation power is dynamically adjusted according to the temperature threshold or the temperature rise rate (such as switching between air cooling and liquid cooling modes). However, such methods have the following defects:

[0004] Response hysteresis: The heat dissipation control strategy based on temperature feedback is in the way of temperature sensor → threshold judgment → heat dissipation mode switching, which belongs to "posteriori" feedback control. There is a time difference between battery heat generation and heat dissipation power adjustment. Especially under the traction condition, the battery heat generation power rises rapidly, and the temperature sensor needs to wait for the heat to conduct to the monitoring point before triggering the heat dissipation mode switching, which results in a lag in heat dissipation response. Local high-temperature areas may have formed inside the battery, accelerating battery aging and even causing thermal runaway; that is to say, the heat dissipation control strategy based on temperature feedback is a passive response and cannot predict the thermal shock caused by sudden changes in working conditions.

[0005] Temperature monitoring blind area: The temperature distribution inside the battery module is uneven, and it is difficult to accurately capture the risk points of thermal runaway relying on discrete temperature sensors, resulting in local failure of the heat dissipation strategy. Summary of the Invention

[0006] Therefore, the purpose of the present invention is to overcome the problems of response hysteresis and temperature monitoring blind area caused by switching the heat dissipation mode based on temperature feedback control in the prior art, and provide a thermal management method and system for electric tensioning equipment. By means of a running condition prediction and active heat dissipation mode switching mechanism, the hysteresis of temperature feedback is eliminated, and the efficiency and effectiveness of thermal management are improved.

[0007] In a first aspect, to solve the above technical problems, the present invention provides a thermal management method for an electric tensioning equipment. The running conditions of the electric tensioning equipment include a traction condition and a tension condition. This thermal management method is used to manage the battery module that powers the electric tensioning equipment, and it includes:

[0008] Determine the running condition of the electric tensioning equipment;

[0009] When the traction condition is triggered, switch to the first heat dissipation mode; wherein, the maximum heat dissipation power Q1 of the first heat dissipation mode satisfies: Q1≥1.5×P*; P* represents the maximum heat generation power of the battery module under the traction condition.

[0010] When the tension condition is triggered, switch to the second heat dissipation mode; wherein, the maximum heat dissipation power Q2 of the second heat dissipation mode satisfies: Q2=(0.3~0.5)×Q1.

[0011] Preferably, when the operating condition switches from the traction condition to the tension condition, it further includes obtaining the temperature distribution of the battery module and determining its highest temperature; if the highest temperature of the battery module is greater than or equal to the first temperature, then perform the following steps: simultaneously operate the first heat dissipation mode and the second heat dissipation mode, and reduce the heat dissipation power of the first heat dissipation mode and increase the heat dissipation power of the second heat dissipation mode until the switching time t0; wherein, reduce the heat dissipation power of the first heat dissipation mode according to the following method:

[0012] ;

[0013] Increase the heat dissipation power of the second heat dissipation mode according to the following method:

[0014] ; represents the heat dissipation power of the first heat dissipation mode at time t; t represents time; k1 is the first factor, used to characterize the speed of stopping the first heat dissipation mode; t0 represents the switching time. represents the heat dissipation power of the second heat dissipation mode at time t; k2 is the second factor, used to characterize the response speed of starting the second heat dissipation mode; wherein, k2>k1 is satisfied.

[0015] Preferably, the switching time t0 characterizes the time required to eliminate the current excess heat stored in the battery module when the first heat dissipation mode and the second heat dissipation mode are operating simultaneously.

[0016] Preferably, obtaining the temperature distribution of the battery module includes deploying temperature sensors at multiple predetermined positions of the battery module to form discrete temperature monitoring points; obtaining the coordinates of each temperature monitoring point and its corresponding temperature measurement value, and the temperature measurement values of all the temperature monitoring points constitute a temperature matrix; for any of the temperature monitoring points, calculating its Euclidean distance to all the temperature monitoring points to obtain a first Euclidean distance, inputting the first Euclidean distance into a radial basis function to obtain a basis function matrix; determining the position-temperature relationship between the temperature monitoring points in the battery module according to the basis function matrix and the temperature matrix; for any target point in the battery module, calculating its Euclidean distance to all the temperature monitoring points to obtain a second Euclidean distance; inputting the second Euclidean distance into the radial basis function to obtain the weight influence value of each monitoring point on the target point; calculating and obtaining the interpolation temperature of the target point according to the position-temperature relationship and the weight influence value of each monitoring point on the target point; traversing all the target points in the battery module to generate the temperature distribution of the battery module.

[0017] Preferably, among the multiple battery cells included in the battery module, the straight-line distance between the geometric center of each battery cell and at least one of the temperature sensors is less than a preset threshold; wherein, the preset threshold is related to the thermal diffusivity of the battery cell and the ambient temperature.

[0018] Preferably, the first heat dissipation mode and the second heat dissipation mode are a liquid cooling heat dissipation mode and an air cooling heat dissipation mode respectively.

[0019] Preferably, the electric tensioning device includes a main motor, and the main motor drives a tension wheel to traction wire transmission; detecting the torque direction of the main motor, if the torque direction is positive, it is determined as the traction working condition, and if it is negative, it is determined as the tension working condition.

[0020] In a second aspect, to solve the above technical problems, the present invention further provides a thermal management system for an electric tensioning device. The operating conditions of the electric tensioning device include a traction working condition and a tension working condition. This thermal management system is used to manage the battery module that supplies power to the electric tensioning device, and it includes,

[0021] A working condition determination module configured to detect and determine the operating condition of the electric tensioning device in real time;

[0022] A heat dissipation control module that generates a first control instruction in response to a traction working condition trigger signal; and generates a second control instruction in response to a tension working condition trigger signal;

[0023] A first heat dissipation module that starts to dissipate heat from the battery module in response to the first control instruction; wherein, the maximum heat dissipation power Q1 of the first heat dissipation module satisfies: Q1≥1.5×P*; P* represents the maximum heat generation power of the battery module under the traction working condition;

[0024] A second heat dissipation module that starts dissipating heat from the battery module in response to the second control instruction; wherein, the maximum heat dissipation power Q2 of the second heat dissipation mode satisfies: Q2 = (0.3 - 0.5) × Q1.

[0025] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0026] The thermal management method and system of the electric traction device described in the present invention are based on working condition determination rather than passive dependence on temperature signals, directly predicting the heat generation demand of the battery (high heat generation in the traction working condition and low heat generation in the tension working condition), actively switching the heat dissipation mode before the sudden change of the heat generation power, preventing the instantaneous high temperature risk of the battery caused by heat dissipation delay from the source, eliminating the hysteresis of temperature feedback, and improving the response speed, efficiency and effectiveness of thermal management.

[0027] Realize the dynamic adaptation of the thermal management strategy to the heat generation demand: forcefully start high heat dissipation in the traction working condition to ensure that the heat dissipation power always covers the maximum heat generation demand and avoid the cumulative heat dissipation of the battery; switch to low heat dissipation in the tension working condition to avoid mis-triggering high-power heat dissipation due to environmental temperature interference and reduce energy waste. Through the precise matching of the working condition and the heat dissipation mode, the energy consumption efficiency is optimized while ensuring the safety of the battery. Description of the Drawings

[0028] In order to make the content of the present invention easier to be clearly understood, the following further describes the present invention in detail according to the specific embodiments of the present invention in combination with the drawings, wherein,

[0029] Figure 1 is a flowchart of the thermal management method of the electric traction device in the preferred embodiment of the present invention;

[0030] Figure 2 is a flowchart of obtaining the temperature distribution of the battery module in the preferred embodiment of the present invention;

[0031] Figure 3 is a structural block diagram of the thermal management system of the electric traction device in the preferred embodiment of the present invention. Detailed Embodiments

[0032] The following further describes the present invention in combination with the drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the examples given are not intended to limit the present invention.

[0033] Embodiment 1

[0034] Refer to Figure 1As shown in the figure, an embodiment of the present invention discloses a thermal management method for an electric tensioning device. The operating conditions of the electric tensioning device include a traction condition and a tension condition. This thermal management method is used to manage the battery module that powers the electric tensioning device, and it includes determining the operating condition of the electric tensioning device; when the traction condition is triggered, switching to the first heat dissipation mode; where the maximum heat dissipation power Q1 of the first heat dissipation mode satisfies: Q1≥1.5×P*; P* represents the maximum heat generation power of the battery module under the traction condition; when the tension condition is triggered, switching to the second heat dissipation mode; where the maximum heat dissipation power Q2 of the second heat dissipation mode satisfies: Q2=(0.3~0.5)×Q1.

[0035] In a specific application scenario, the electric tensioning device includes a traction condition and a tension condition:

[0036] The traction condition refers to the working state in which the electric tensioning device actively outputs power and pulls a wire or cable through a drive system (such as a main motor and a slave motor group) to move it in a specific direction. In this condition, the device is operating at a high load and requires the battery module to provide a large current to meet the high-power demand; under the traction condition, the battery discharges at a high rate (such as above 2C), and the heat generation power mainly comes from the internal resistance; due to the large-current discharge, the temperature of the battery cells inside and the connecting components between the modules rises rapidly, and local hot spots may be formed. For example, in scenarios such as power construction for pulling cables through pipes and actively lifting heavy objects during hoisting.

[0037] The tension condition refers to the working state in which the electric tensioning device passively maintains the tension of the wire to prevent it from loosening or being overly tightened; in this condition, the device is operating at a low load, and the battery output power is mainly used to maintain the control circuit and the braking system. In this condition, the battery discharges at a low rate (such as 0.2C~0.5C), and the heat generation power is significantly reduced; external high temperature or sunlight radiation may cause the battery temperature to rise slowly, but there is no intense heat generation. For example, in scenarios such as maintaining a constant wire tension during wire laying, relaxation control when the cable is hanging, and static tension maintenance when the device is on standby.

[0038] The power system of the electric tensioning device includes a main motor and a slave motor group. The main motor drives the traction and conveying of the wire, and the slave motor group drives the distributed tension wheels in sections to assist in conveying the wire and maintain a constant tension of the wire during conveying. In the electric tensioning device, the core goal of determining the operating condition is to accurately distinguish between high-load (traction) and low-load (tension) states to match the corresponding heat dissipation strategies. Common methods for determining the operating condition include torque direction detection, current detection, temperature feedback, etc. In a preferred embodiment of the present invention, based on the topological structure of the power system of the electric tensioning device, the operating condition of the electric tensioning device is determined by detecting the torque direction of the main motor: if the torque direction is positive, it is determined as the traction condition, and if it is negative, it is determined as the tension condition.

[0039] Current determination of operating conditions: Current is vulnerable to interference from factors such as battery aging, internal resistance changes, and circuit harmonics, and it cannot distinguish dynamic load fluctuations. In complex operating conditions (such as intermittent traction and wire jamming), the direction of the current may fluctuate frequently (such as the change in current polarity caused by motor start and stop).

[0040] Comparing with the drawbacks of the conventional method of determining operating conditions based on the direction of current, in the embodiments of the present invention, the operating conditions are determined by the torque direction. The torque signal can be detected within milliseconds, with strong real-time performance. The torque direction only depends on the operating state of the device itself and is not affected by external interference, with high anti-interference ability. The torque direction is directly output by the motor controller, and the signal is stable and reliable. The torque direction directly reflects the mechanical load state of the device and is strongly coupled with the heat generation demand of the battery, without the need for indirect calculation. In complex scenarios such as current fluctuations and temperature interference, it can still accurately distinguish the operating conditions and avoid heat dissipation failure or energy waste caused by misjudgment.

[0041] The difference between the first heat dissipation mode and the second heat dissipation mode lies in the different heat dissipation powers. The first heat dissipation mode has a large heat dissipation power, and the second heat dissipation mode has a small heat dissipation power. In the embodiments of the present invention, two completely different heat dissipation methods are preferably used to form two heat dissipation modes, namely the liquid cooling heat dissipation mode and the air cooling heat dissipation mode. Among them, in the liquid cooling heat dissipation mode, a liquid circulation system (such as water, ethylene glycol solution or special coolant) is used as the heat conduction medium to quickly transfer the heat generated by the battery module to the external radiator, and finally dissipate it into the environment through air or a secondary cooling system. Its core principle is to utilize the high specific heat capacity and high thermal conductivity of the liquid to achieve efficient heat transfer. In the air cooling heat dissipation mode, the heat on the battery surface is transferred to the air through forced air convection (driven by a fan) or natural convection. Its core depends on the air flow rate and the surface area of the heat sink. Based on different heat dissipation methods, two different heat dissipation modes are formed, and two heat dissipation methods with different heat dissipation powers are respectively formed. Of course, choosing the same heat dissipation mode (such as liquid cooling or air cooling) and operating at different heat dissipation powers to adapt to the traction and tension conditions of this application can also solve the problems of this application, which is selected according to the actual application scenario.

[0042] The thermal management method of the electric traction and tension device described in the present invention is based on the determination of operating conditions rather than passive dependence on temperature signals. It directly predicts the heat generation demand of the battery (high heat generation in traction conditions and low heat generation in tension conditions), actively switches the heat dissipation mode before the sudden change of the heat generation power, prevents the instantaneous high temperature risk of the battery caused by heat dissipation delay from the root, eliminates the hysteresis of temperature feedback, and improves the response speed, efficiency and effectiveness of thermal management.

[0043] Among them, it is specified that the maximum heat dissipation power Q1 of the first heat dissipation mode satisfies: Q1 ≥ 1.5 × P*; P* represents the maximum heat generation power of the battery module under traction conditions. It should be noted that the maximum heat generation power of the battery module under traction conditions is calculated and determined according to the discharge current and internal resistance: P* = I2 ×R; I represents the discharge current; R represents the internal resistance. By setting Q1 ≥ 1.5×P* to cover the peak heat generation, ensuring that the heat dissipation power is always higher than the maximum heat generation power, the battery temperature is forced to be suppressed within the safety threshold (such as below 50 degrees Celsius); and the temperature rise inertia is suppressed: the heat generation of the battery has instantaneity and cumulativeness, and 1.5 times the maximum heat generation power provides redundancy for heat generation fluctuations and heat dissipation delays, eliminating the risk of temperature rise lag.

[0044] Under the tension condition, the heat generation power of the battery decreases significantly, but the ambient temperature may cause additional temperature rise. Set Q2 = (0.3 - 0.5)×Q1, which can not only offset the ambient heat interference but also avoid the waste of energy in high-power heat dissipation.

[0045] The thermal management method of the electric traction device described in the present invention anticipates the change of heat load according to the torque direction and starts the adaptive heat dissipation mode in advance to solve the inherent hysteresis of temperature feedback. In the specific implementation process, when the current traction condition is switched to the tension condition, if the battery temperature is still at a high level, there may be a risk of directly switching to the air-cooling mode, that is, the air-cooling heat dissipation capacity is not enough to quickly reduce the battery temperature, resulting in out-of-control temperature rise; in addition, when the liquid cooling is suddenly turned off, the residual heat cannot be dissipated in time, and the battery temperature may rebound by 3 - 8°C. To solve the problem of out-of-control temperature rise caused by the sudden drop of heat dissipation capacity during the high-temperature condition switch, in a further implementation scheme of the present invention, when the operating condition is switched from the traction condition to the tension condition, it also includes obtaining the temperature distribution of the battery module and determining its highest temperature; if the highest temperature of the battery module is greater than or equal to the first temperature, the following steps are executed: simultaneously operate the first heat dissipation mode and the second heat dissipation mode, and reduce the heat dissipation power of the first heat dissipation mode and increase the heat dissipation power of the second heat dissipation mode until the switching time t0 is reached. Through the collaborative control of condition-dominated switching + temperature feedback correction, not only the fast response advantage of condition switching is retained, but also the risk of insufficient air-cooling capacity in high-temperature scenarios is avoided, achieving an optimal balance between heat dissipation efficiency and energy consumption.

[0046] Among them, the heat dissipation power of the first heat dissipation mode is reduced according to the following method:

[0047] ;

[0048] The heat dissipation power of the second heat dissipation mode is increased according to the following method:

[0049] ;

[0050] represents the heat dissipation power of the first heat dissipation mode at time t; t represents time; k1 is the first factor, used to characterize the speed of stopping the first heat dissipation mode; t0 represents the switching time; represents the heat dissipation power of the second heat dissipation mode at time t; k2 is the second factor, used to characterize the response speed of starting the second heat dissipation mode; where k2 > k1 is satisfied.

[0051] In a specific application scenario, when the operating condition switches from the traction condition to the tension condition, the temperature distribution of the battery module is obtained. If the highest temperature of the battery module is greater than or equal to the first temperature, it indicates that the current temperature of the battery module is still at a high level. At this time, switch to the simultaneous operation of the second heat dissipation mode and the first heat dissipation mode. Through the coordinated transition of the dual modes, the total heat dissipation power decreases smoothly, ensuring that the heat dissipation capacity is always higher than the residual heat generation. Among them, the first temperature is the threshold temperature for triggering the coordinated heat dissipation of the dual modes. The setting of the first temperature is the result of multi-objective trade-off, determined by combining battery chemistry, thermodynamic models, heat dissipation system capabilities, and measured data. On the premise of ensuring safety, it is as close as possible to the optimal range of battery performance, and at the same time, it matches the thermal inertia requirements of the operating condition switch. For example, the first temperature is set to 45°C.

[0052] During the transition stage of the dual-mode system, the heat dissipation power of the first heat dissipation mode decays exponentially, and the heat dissipation power of the second heat dissipation mode increases exponentially, realizing a smooth decrease in the total heat dissipation power, solving the problem while reducing the ineffective heat dissipation energy consumption.

[0053] Reduce the heat dissipation power of the first heat dissipation mode according to the following method: , k1 is the first factor, with the unit of s -1 , the smaller k1 is, the slower the decay of the heat dissipation power of the first heat dissipation mode, and the gentler the exit of the heat dissipation capacity; the larger k1 is, the faster the first heat dissipation mode closes. The first factor is set in combination with the thermal inertia of the battery module and the residual heat release rate, and is related to the heat capacity or temperature difference of the battery. For example, k1 = 0.1.

[0054] Increase the heat dissipation power of the second heat dissipation mode according to the following method: , k2 is the second factor, with the unit of s -1 , the second factor is set in combination with the thermal inertia of the battery module and the residual heat release rate, and is related to the heat capacity or temperature difference of the battery. For example, k2 = 0.2.

[0055] During the heat dissipation mode switching process, the core purpose of controlling k2 > k1 is to ensure the smooth transition of the total heat dissipation power by controlling the power growth rate of the second heat dissipation mode to be greater than the decay rate of the power of the first heat dissipation mode, suppressing temperature rebound and local overheating, improving the temperature field uniformity, and optimizing the energy consumption efficiency. Among them, the understanding of improving the temperature field uniformity is as follows: The main function of air cooling is not only to dissipate heat, but also to balance the module temperature through air flow diffusion, quickly reach the effective value of the air cooling power, accelerate the air flow circulation, reduce local hot spots, and at the same time can shorten the time window to reach effective heat dissipation, making the temperature distribution more uniform.

[0056] In one application scenario, when the traction condition is switched to the tension condition, the dual-mode cooperatively transitions. The temperature rebounds from +6°C to +0.5°C, and the temperature difference shrinks from 12°C to 3°C; the liquid cooling power decays from 750W according to decay, and the air cooling increases from 0W according to increase. The switching is completed within 10 seconds, and the temperature fluctuation ≤ 1°C.

[0057] Specifically, the switching time t0 represents the time required to eliminate the currently stored excess heat of the battery module under the simultaneous operation of the first heat dissipation mode and the second heat dissipation mode.

[0058] In a specific application scenario, the switching time t0 is the total time for the two heat dissipation modes to work together, and it is necessary to ensure that the currently stored excess heat (the additional thermal energy that needs to be eliminated by heat) of the battery module is completely eliminated within this time. Adjust the switching duration according to the real-time thermal state to completely eliminate the temperature rebound; be compatible with complex conditions such as temperature mutations, battery aging, and environmental interference.

[0059] Above, the embodiment solution of the present invention based on dual-mode cooperation and the thermal management system with traditional temperature feedback control have the comparison characteristics as shown in Table 1 below:

[0060] Table 1

[0061] Comparison item Temperature feedback control Embodiment of the present invention Response logic Passive response Active prediction Thermal accuracy of battery management High risk of local overheating Uniform regulation of the temperature field of the whole module Energy consumption efficiency High (fixed or frequently switched cooling power) Low (dynamically allocated as needed) Extreme working condition protection Single mode Dual-mode collaboration to cover the risk of thermal runaway

[0062] Furthermore, obtain the temperature distribution of the battery module. As shown in reference to Figure 2 , it includes deploying temperature sensors at multiple predetermined positions of the battery module to form discrete temperature monitoring points; obtaining the coordinates of each temperature monitoring point and its corresponding temperature measurement value, and the temperature measurement values of all the temperature monitoring points constitute a temperature matrix; for any of the temperature monitoring points, calculate its Euclidean distance to all the temperature monitoring points to obtain a first Euclidean distance, input the first Euclidean distance into a radial basis function to obtain a basis function matrix; determine the position-temperature relationship between each temperature monitoring point in the battery module according to the basis function matrix and the temperature matrix; for any target point in the battery module, calculate its Euclidean distance to all the temperature monitoring points to obtain a second Euclidean distance; input the second Euclidean distance into the radial basis function to obtain the weight influence value of each monitoring point on the target point; calculate and obtain the interpolation temperature of the target point according to the position-temperature relationship and the weight influence value of each monitoring point on the target point; traverse all the target points in the battery module to generate the temperature distribution of the battery module.

[0063] In a specific application scenario, temperature sensors are deployed in high-risk areas of the battery module (such as cell gaps, tab connections, geometric centers of battery cells, etc.). In addition, 10% more temperature sensors are deployed at the edges and corners of the battery module to prevent blind spots in boundary temperature monitoring. When deploying the temperature sensors, among the multiple battery cells included in the battery module, the straight-line distance between the geometric center of each battery cell and at least one of the temperature sensors is less than a preset threshold. Wherein, the preset threshold is related to the thermal diffusivity of the battery cell and the ambient temperature.

[0064] The preset threshold defines the maximum deployment spacing of the temperature sensors, and its physical meaning is: within the time window The maximum distance required for heat to diffuse from the critical temperature of battery thermal runaway to the ambient temperature. By calculating the temperature sensor spacing through the preset threshold, it is ensured that the heat of any battery cell can be transferred to at least one temperature sensor within the diffusion time window, and at the same time, it is ensured that the heat diffusion path is fully covered to respond to the thermal runaway risk within the time window

[0065] Specifically, the preset threshold Satisfies:

[0066] ;

[0067] Wherein, Represents the preset threshold; λ represents the thermal diffusivity, which is the ratio of the material's heat conduction ability to its heat storage ability, with the unit of length 2 / time; Represents the distance that heat diffuses within the time window ; T a Represents the critical temperature (unit: Kelvin K), that is, the highest temperature allowed for the battery. Exceeding this temperature may cause thermal runaway or failure; T b Represents the ambient temperature (unit: Kelvin K).

[0068] Obtaining the temperature distribution of the battery module includes:

[0069] Obtaining the coordinates (x i , y i , z i ) of each temperature monitoring point and its corresponding temperature measurement value Ti. Wherein, i represents the serial number of the temperature monitoring point, i = 1, 2,..., n, and n represents the number of temperature monitoring points and n ≥ 3.

[0070] The temperature measurement values of all the temperature monitoring points form a temperature matrix ;

[0071] ​For any of the temperature monitoring points, calculate its Euclidean distance to all temperature monitoring points to obtain a first Euclidean distance, and input the first Euclidean distance into a radial basis function to obtain a basis function matrix ; This basis function matrix is an n×n matrix;

[0072] Determine the position-temperature relationship between the temperature monitoring points in the battery module according to the basis function matrix and the temperature matrix T; Among them, the position-temperature relationship matrix is denoted as , and obtain the position-temperature relationship matrix by solving the linear equation system (). .

[0073] For any target point (x, y, z) in the battery module, calculate its Euclidean distance to all temperature monitoring points to obtain a second Euclidean distance d i :

[0074] Input the second Euclidean distance d i into the radial basis function , obtain the weight influence value of each monitoring point on the target point, and the weight influence values of all monitoring points on the target point form a weight influence value matrix;

[0075] Calculate the interpolation temperature T(x, y, z) of the target point according to the position-temperature relationship and the weight influence value of each monitoring point on the target point; traverse all target points in the battery module to generate the temperature distribution of the battery module.

[0076] The radial basis function can be a Gaussian function or an inverse quadratic function ; is the shape parameter. Among them, the shape parameter of the Gaussian function is determined as follows:

[0077] ; davg represents the average distance between all data points; β represents an empirical coefficient, usually taking β = 2~3, which is used to balance locality and globality; for example, if the average spacing davg of the temperature monitoring points = 0.2m, then = 2.5m -1 .

[0078] The shape parameter of the inverse quadratic function is determined as follows:

[0079] ; d min represents the minimum distance between data points, which avoids the function being too steep and causing numerical instability.

[0080] Specifically, the interpolation temperature calculation method is as follows: .

[0081] represents the interpolation temperature of the target point (x j , y j , z j ); j represents the target point number; i represents the temperature monitoring point number;

[0082] represents the Euclidean distance between the temperature monitoring point (x i , y i , z i ) and the target point (x j , y j , z j );

[0083] is the calculation result of inputting the Euclidean distance between the temperature monitoring point (x i , y i , z i ) and the target point (x j , y j , z j ) into the radial basis function, representing the weight influence value of the temperature monitoring point (x i , y i , z i ) on the target point (x j , y j , z j );

[0084] is an element of the matrix , obtained by solving the linear equation system ( );

[0085] is the basis function matrix composed of , ; m and n both represent any monitoring point numbers.

[0086] Among them, represents the Euclidean distance between the temperature monitoring point (x m , y m , z m ) and the temperature monitoring point (x n , y n , z n );

[0087] is the temperature monitoring point (x m , ym , z m ), and the Euclidean distance from the temperature monitoring point (x n , y n , z n ) is input into the calculation result of the radial basis function.

[0088] Due to factors such as structural limitations and cost control, the deployment location and quantity of temperature sensors are restricted. Or, temperature sensors are not deployed at the hot spot location, and the obtained discrete temperature measurement values cannot identify the local temperature in the area not covered by the temperature sensors, resulting in a risk of missing high-temperature detection. To solve this problem, in the implementation scheme of this invention application, a complete temperature field is reconstructed based on the interpolation method of the radial basis function. Even if the hot spot is located in the blind area of the temperature sensor, its position can still be predicted through gradient changes. For example, through six sparse temperature sensors + radial basis function interpolation, a coverage effect equivalent to that of 48 temperature sensors can be achieved. At the same time, when a certain temperature sensor fails, the interpolation algorithm reconstructs its temperature data through surrounding nodes, maintaining the integrity of the temperature field, and improving the integrity and reliability of temperature data while reducing costs.

[0089] Embodiment 2

[0090] Based on the same inventive concept, the embodiment of the present invention discloses a thermal management system for an electric traction device. The operating conditions of the electric traction device include a traction condition and a tension condition. This thermal management system is used to manage the battery module that powers the electric traction device. Referring to Figure 3 as shown, it includes

[0091] A working condition determination module configured to detect and determine the operating conditions of the electric traction device in real time;

[0092] A heat dissipation control module that generates a first control instruction in response to a traction condition trigger signal; and generates a second control instruction in response to a tension condition trigger signal;

[0093] A first heat dissipation module that starts to dissipate heat from the battery module in response to the first control instruction; wherein, the maximum heat dissipation power Q1 of the first heat dissipation module satisfies: Q1 ≥ 1.5 × P*; P* represents the maximum heat generation power of the battery module under the traction condition;

[0094] A second heat dissipation module that starts to dissipate heat from the battery module in response to the second control instruction; wherein, the maximum heat dissipation power Q2 of the second heat dissipation mode satisfies: Q2 = (0.3 - 0.5) × Q1.

[0095] The thermal management system for the electric traction device described in the embodiment of the present invention is used to execute the thermal management method for the electric traction device in Embodiment 1, and it has the same technical effects, which will not be elaborated here.

[0096] In summary, for the thermal management method and system of the electric stretching device described in the present invention, based on the working condition determination rather than passive reliance on temperature signals, it directly predicts the heat generation requirements of the battery (high heat generation in the traction working condition and low heat generation in the tension working condition), actively switches the heat dissipation mode before the sudden change of the heat generation power, prevents the instantaneous high temperature risk of the battery caused by heat dissipation delay from the root, eliminates the hysteresis of temperature feedback, and improves the response speed, efficiency and effectiveness of thermal management.

[0097] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0098] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate for implementing in the process Figure 1 a process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0099] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements in the process Figure 1 a process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0100] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 a process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0101] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. Thermal management method for an electric stretching device, the operating conditions of the electric stretching device include a traction condition and a tension condition, characterized in that: The thermal management method is used to manage the battery module that supplies power to the electric stretching device, and includes: Determining the operating condition of the electric tensioning device; When the traction condition is triggered, the first heat dissipation mode is switched; wherein the maximum heat dissipation power Q1 of the first heat dissipation mode satisfies: Q1 ≥ 1.5 × P*; P* represents the maximum heat generation power of the battery module under the traction condition; When the tension condition is triggered, the second heat dissipation mode is switched; wherein the maximum heat dissipation power Q2 of the second heat dissipation mode satisfies: Q2=(0.3~0.5)×Q1; When the operating condition is switched from traction condition to tension condition, it also includes: Obtaining the temperature distribution of the battery module and determining its maximum temperature; If the maximum temperature of the battery module is greater than or equal to the first temperature, the following steps are performed: Running the first heat dissipation mode and the second heat dissipation mode simultaneously, reducing the heat dissipation power of the first heat dissipation mode and increasing the heat dissipation power of the second heat dissipation mode until a switching time t0 is reached; The heat dissipation power of the first heat dissipation mode is reduced according to the following method: ； Increase the heat dissipation power of the second heat dissipation mode as follows: ; represents the heat dissipation power of the first heat dissipation mode at time t; t represents time; k1 is the first factor used to characterize the speed of stopping the first heat dissipation mode; t0 represents the switching time; represents the heat dissipation power of the second heat dissipation mode at time t; k2 is the second factor used to characterize the response speed of starting the second heat dissipation mode.

2. The thermal management method of the electric traction device according to claim 1, wherein: The first factor and the second factor satisfy k2>k1.

3. The thermal management method of the electric traction device according to claim 1, characterized in that: The switching time t0 represents the time required to eliminate the excess heat currently stored in the battery module when the first heat dissipation mode and the second heat dissipation mode are running simultaneously.

4. The thermal management method of the electric traction device according to claim 1, characterized in that: obtaining the temperature distribution of the battery module, include, Deploy temperature sensors at a plurality of predetermined positions of the battery module to form discrete temperature monitoring points; Acquire the coordinates of each temperature monitoring point and its corresponding temperature measurement value, and the temperature measurement values of all the temperature monitoring points constitute a temperature matrix; For any of the temperature monitoring points, calculate the Euclidean distance from the temperature monitoring point to all the temperature monitoring points to obtain a first Euclidean distance, and input the first Euclidean distance into a radial basis function to obtain a basis function matrix; Determining the position-temperature relationship between each temperature monitoring point in the battery module according to the basis function matrix and the temperature matrix; For any target point in the battery module, calculate the Euclidean distance from the target point to all temperature monitoring points to obtain a second Euclidean distance; Inputting the second Euclidean distance into the radial basis function to obtain a weighted influence value of each monitoring point on the target point; The interpolation temperature of the target point is obtained by calculating the position-temperature relationship and the weighted influence value of each monitoring point on the target point; All target points in the battery module are traversed to generate the temperature distribution of the battery module.

5. The thermal management method of the electric traction device according to claim 4, characterized in that: Among the multiple battery cells included in the battery module, the straight-line distance between the geometric center of each battery cell and at least one of the temperature sensors is less than a preset threshold; wherein the preset threshold is related to the thermal diffusivity of the battery cell and the ambient temperature.

6. The thermal management method of the electric stretching device according to claim 1, characterized in that: The first heat dissipation mode and the second heat dissipation mode are respectively a liquid cooling mode and an air cooling mode.

7. The thermal management method of the electric traction device according to any one of claims 1-6, characterized in that: The electric tensioning device includes a main motor, which drives a tension wheel to pull the wire for transmission; the torque direction of the main motor is detected, and if the torque direction is positive, it is determined to be a traction condition, and if it is negative, it is determined to be a tension condition.

8. Thermal management system for an electric stretching device, which executes the thermal management method for an electric stretching device according to any one of claims 1-7. The operating conditions of the electric stretching device include a traction condition and a tension condition, and are characterized in that: The thermal management system is used to manage the battery module that supplies power to the electric stretching device, and includes: The operating condition determination module is configured to detect and determine the operating condition of the electric traction device in real time; The heat dissipation control module generates a first control instruction in response to the traction condition trigger signal; And generates a second control instruction in response to the tension condition trigger signal; The first heat dissipation module starts to dissipate heat from the battery module in response to the first control instruction; wherein, the maximum heat dissipation power Q1 of the first heat dissipation module satisfies: Q1≥1.5×P*; P* represents the maximum heat generation power of the battery module under the traction condition; The second heat dissipation module starts to dissipate heat from the battery module in response to the second control instruction; wherein, the maximum heat dissipation power Q2 of the second heat dissipation mode satisfies: Q2=(0.3~0.5)×Q1.

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