Battery module low temperature test method and system for substation inspection robot

Abstract

The present application relates to the technical field of battery control, in particular to a battery module low-temperature test method and system for a substation inspection robot. The method obtains a surface temperature reference change rate, an initial surface temperature and an initial measured impedance before heating; closes a heating loop to obtain cumulative heating energy; opens the heating to obtain a terminal surface temperature and a terminal measured impedance; obtains a heating temperature rise value based on the terminal surface temperature, the initial surface temperature and the surface temperature reference change rate; obtains a convection heat loss rate based on the cumulative heating energy and the heating temperature rise value; obtains an internal resistance response residual rate based on the terminal surface temperature, the terminal measured impedance and the initial measured impedance; and obtains a start control strategy of the battery module based on the convection heat loss rate and the internal resistance response residual rate. The present application effectively solves the problem of start-up crash or invalid heating caused by the inability to accurately evaluate the battery state by obtaining the convection heat loss rate and the internal resistance response residual rate, and improves the environmental adaptability of the robot.

Description

Technical Field

[0001] This invention relates to the field of battery control technology, specifically to a low-temperature testing method and system for the battery module of a substation inspection robot. Background Technology

[0002] As a crucial component of the smart grid operation and maintenance system, substation inspection robots operate long-term in uncontrolled outdoor environments, undertaking the critical tasks of equipment status monitoring and data acquisition. In frigid winters or high-altitude areas, the extremely low ambient temperatures, often accompanied by strong winds, present severe challenges to the robot's power battery system.

[0003] Existing battery management systems typically employ a surface temperature sensor-based heating control strategy to address low-temperature startup issues. This involves closing the heater for preheating when the battery surface temperature is detected to be below a set threshold, and stopping heating and allowing the system to power on when the surface temperature reaches the threshold. While this control logic performs well in a constant-temperature, windless laboratory environment, it presents significant technical limitations in outdoor, unsteady-state thermal environments. Firstly, in strong winds and convection, heat from the battery module surface dissipates rapidly. If the battery management system relies solely on surface temperature for judgment, most of the heat generated by the heater will be carried away by the environment, causing the surface temperature to fail to reach the preset temperature threshold for a long time. The system will then fall into a state of continuous ineffective heating until the battery is depleted, rendering the robot unable to perform its tasks. On the other hand, the battery module is composed of multiple layers of cells, brackets, and potting compound, and its heat conduction has a significant lag. During rapid heating, the battery surface temperature may rise rapidly and trigger a heating completion signal, but the internal electrolyte temperature remains at an extremely low level, with low ionic conductivity and extremely high internal resistance. If the system misjudges this as ready and performs a full-power start (such as a high-current start-up of the drive motor), the extremely high internal resistance voltage drop will cause the terminal voltage to drop instantly below the cutoff voltage, triggering the battery management system's undervoltage protection, causing the robot to crash upon startup.

[0004] Therefore, existing technologies rely solely on a single battery surface temperature index, which cannot effectively distinguish between two fundamentally different physical conditions: excessively rapid heat dissipation from the external environment and delayed internal heat conduction. Consequently, it is difficult to accurately assess the battery's true power output capability and to accurately control the start-up timing and power strategy of the substation inspection robot, affecting the robot's uptime and operational reliability in low-temperature and complex environments. Summary of the Invention

[0005] To address the technical problem that existing technologies rely solely on battery surface temperature, making it impossible to effectively distinguish between two physical conditions—rapid external heat dissipation and delayed internal heat conduction—and consequently, difficulty in accurately assessing the battery's true power output capability, thus affecting the stable operation of substation inspection robots, this invention aims to provide a low-temperature testing method and system for battery modules of substation inspection robots. The specific technical solution adopted is as follows:

[0006] In a first aspect, one embodiment of the present invention provides a method for low-temperature testing of the battery module of a substation inspection robot, the method comprising the following steps:

[0007] Before the heating circuit is closed, the surface temperature data of the battery module within a first preset time period is obtained to calculate the surface temperature reference change rate, and the initial surface temperature and initial measured impedance of the battery module before heating are obtained; the heating circuit is closed for a second preset time period, and the accumulated heating energy is obtained according to the voltage and current at each moment; after the heating circuit is disconnected and a preset thermal relaxation time is waited, the termination surface temperature and termination measured impedance are obtained.

[0008] Based on the termination surface temperature, initial surface temperature, surface temperature baseline change rate and related duration, the heating temperature rise value after eliminating environmental interference is obtained.

[0009] The theoretical adiabatic temperature rise is obtained based on the accumulated heating energy, and the convective heat loss rate is obtained based on the difference between the heating-induced temperature rise and the theoretical adiabatic temperature rise.

[0010] The thermal equilibrium reference impedance is obtained based on the termination surface temperature. The internal resistance response residual rate is obtained by combining the deviation of the termination measured impedance from the thermal equilibrium reference impedance with the initial measured impedance.

[0011] The startup control strategy of the battery module is obtained based on the convective heat loss rate and the internal resistance response residual rate.

[0012] Furthermore, the method for obtaining the heating-induced temperature rise is as follows:

[0013] The difference between the final surface temperature and the initial surface temperature is taken as the actual temperature change value;

[0014] The sum of the second preset duration and the preset thermal relaxation duration is used as the reference duration.

[0015] The product of the surface temperature reference rate of change and the reference duration is used as the change value of the ambient reference temperature.

[0016] The difference between the actual temperature change and the ambient reference temperature change is taken as the heating-induced temperature rise.

[0017] Furthermore, the method for obtaining the convective heat loss rate is as follows:

[0018] Obtain the preset total heat capacity constant of the module; wherein, the total heat capacity constant of the module is determined based on the weighted sum of the product of the specific heat capacity and mass of each component in the battery module;

[0019] The ratio of the accumulated heating energy to the total heat capacity constant of the module is used as the theoretical adiabatic temperature rise value.

[0020] The result of negatively correlating and normalizing the ratio of the heating-induced temperature rise to the theoretical adiabatic temperature rise is taken as the convective heat loss rate.

[0021] Furthermore, the method for obtaining the residual rate of the internal resistance response is as follows:

[0022] Obtain the preset thermal balance impedance lookup table, and determine the corresponding thermal balance reference impedance by querying the thermal balance impedance lookup table through the termination surface temperature.

[0023] The difference between the measured impedance at termination and the thermal equilibrium reference impedance is taken as the first difference;

[0024] The ratio of the first difference to the initial measured impedance is taken as the internal resistance response residual rate.

[0025] Furthermore, the method for obtaining the startup control strategy is as follows:

[0026] When the internal resistance response residual rate is less than or equal to the preset thermal hysteresis threshold, the start-up control strategy is full-power start-up;

[0027] When the internal resistance response residual rate is greater than the preset thermal hysteresis threshold, it is determined whether the convective heat loss rate is greater than the preset heat loss threshold.

[0028] If the convective heat loss rate is greater than the preset heat loss threshold, the control strategy will be degraded startup.

[0029] If the convective heat loss rate is less than or equal to the preset heat loss threshold, then check the number of iterations in the current test.

[0030] If the number of iterations is less than the preset maximum number of iterations, the control strategy is to maintain heating and return to the step of acquiring surface temperature data;

[0031] If the number of iterations reaches the preset maximum number of iterations, the start control strategy will be degraded startup.

[0032] Furthermore, the method for obtaining the downgrade startup is as follows:

[0033] The difference between the voltage at the end of the preset thermal relaxation time and the minimum allowable operating voltage of the battery module is used as the limiting voltage.

[0034] The ratio of the defined voltage to the measured termination impedance is used as the reference current;

[0035] The product of the preset safety factor and the reference current is taken as the maximum allowable current;

[0036] The maximum allowable current is sent as a power limit boundary to the robot's controller, which then controls the robot to operate at the limited power.

[0037] Furthermore, the method for obtaining the initial measured impedance and the final measured impedance is as follows:

[0038] An electrical pulse of preset amplitude is applied to the battery module, and the voltage change and loop current at the pulse moment are collected; the voltage change is the difference between the terminal voltages before and after the pulse is applied.

[0039] The ratio of the voltage change to the loop current is used as the measured impedance.

[0040] Furthermore, the method for obtaining the surface temperature reference change rate is as follows:

[0041] The difference between the surface temperature data at the end time and the initial time within the first preset time period is obtained as the first temperature change analysis value.

[0042] The ratio of the first temperature change analysis value to the total duration of the first preset time period is used as the baseline change rate of surface temperature.

[0043] Furthermore, the method for obtaining the accumulated heating energy is as follows:

[0044] Obtain the product of voltage and current at each moment within the second preset time period, and use it as the reference power at the corresponding moment.

[0045] The result of integrating the reference power at all times within the second preset time period is taken as the cumulative heating energy.

[0046] Secondly, another embodiment of the present invention provides a low-temperature testing system for the battery module of a substation inspection robot. The system includes: a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any of the above methods.

[0047] The present invention has the following beneficial effects:

[0048] This invention first obtains the baseline rate of change of surface temperature, the initial surface temperature of the battery module before heating, and the initial measured impedance before the heating circuit is closed. This is beneficial for establishing a baseline zero point for evaluating the temperature rise amplitude and impedance change, and for quantifying the background temperature drift rate without active intervention. Then, the cumulative heating energy is obtained by closing the heating circuit, which is beneficial for subsequent use as input to the heat capacity model, providing a physical energy benchmark for evaluating the actual temperature rise efficiency. Furthermore, the heating circuit is disconnected to obtain the termination surface temperature and termination measured impedance, which is beneficial for subsequent acquisition of final state data reflecting the true thermal response characteristics of the battery. Then, based on the termination surface temperature, initial surface temperature, baseline rate of change of surface temperature, and related duration, the heating-induced temperature rise value after eliminating environmental interference is obtained, accurately reflecting the thermal response caused only by active heating excitation, eliminating the natural temperature drift interference introduced by external wind cooling or sunlight, which is beneficial for subsequent accurate calculation of convective heat loss rate. Finally, based on the cumulative heating energy, the theoretical adiabatic temperature rise value is obtained, accurately reflecting the ideal adiabatic temperature rise. The theoretical upper limit of temperature rise is assumed. Then, based on the difference between the heating-induced temperature rise and the theoretical adiabatic temperature rise, the convective heat loss rate is obtained, which accurately reflects the degree of energy loss caused by the current environmental wind cooling effect. This is helpful for the subsequent system to judge the effectiveness of heating operations and avoid ineffective energy consumption. Furthermore, the thermal equilibrium reference impedance is obtained based on the termination surface temperature, which accurately reflects the ideal low impedance benchmark when the internal and external temperatures of the battery are assumed to be the same. Then, based on the deviation of the termination measured impedance from the thermal equilibrium reference impedance, combined with the initial measured impedance, the internal resistance response residual rate is obtained, which accurately reflects the lag of the internal electrolyte activity relative to the surface temperature indication. This is helpful for the subsequent system to identify false ready signals and prevent undervoltage crashes. Finally, based on the convective heat loss rate and the internal resistance response residual rate, the start-up control strategy of the battery module is accurately obtained. This helps to ensure that full-power start is not forced when the internal components are not fully heated, and to stop losses in time when there is ineffective heating due to strong external winds. This effectively improves the robot's environmental adaptability and operational reliability in low-temperature and complex environments. Attached Figure Description

[0049] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a schematic flowchart illustrating a low-temperature testing method for the battery module of a substation inspection robot according to an embodiment of the present invention.

[0051] Figure 2 This is a structural diagram of a low-temperature testing system for the battery module of a substation inspection robot provided in one embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of a computer device provided according to an embodiment of the present invention. Detailed Implementation

[0053] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of the low-temperature testing method and system for the battery module of the substation inspection robot proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0055] The following description, in conjunction with the accompanying drawings, details the specific scheme of the low-temperature testing method and system for the battery module of the substation inspection robot provided by this invention.

[0056] Example 1:

[0057] This invention proposes a low-temperature testing method for the battery module of a substation inspection robot. Please refer to [link / reference]. Figure 1 The diagram illustrates a schematic flowchart of a low-temperature testing method for the battery module of a substation inspection robot according to an embodiment of the present invention. The method includes the following steps:

[0058] Step S1: Before closing the heating circuit, acquire the surface temperature data of the battery module within a first preset time period to calculate the surface temperature reference change rate, and acquire the initial surface temperature and initial measured impedance of the battery module before heating; close the heating circuit for a second preset time period, and acquire the cumulative heating energy based on the voltage and current at each moment; disconnect the heating circuit and wait for a preset thermal relaxation time, and acquire the termination surface temperature and termination measured impedance.

[0059] Specifically, because substation inspection robots operate in open outdoor environments for extended periods, the surface temperature of battery modules naturally drifts due to uncontrollable factors such as air temperature fluctuations, solar radiation, and ambient wind speed. Directly adding this background temperature change to the temperature rise data during the active heating process would lead to significant deviations in subsequent assessments of heating efficiency (heat loss). Therefore, before the power system is fully closed, this embodiment executes a standard timing sequence including silent sampling, state locking, energy measurement, and thermal relaxation. This aims to obtain pure thermal response data caused solely by active excitation, enabling the subsequent system to accurately distinguish between the effects of external environmental heat dissipation and internal heat transfer hysteresis.

[0060] Before the heating circuit is closed, the system first acquires the surface temperature data of the battery module within a first preset time period. In this embodiment, the duration of the first preset time period is set to 5 seconds to ensure that short-term environmental temperature change trends can be captured without taking up too much test preparation time. The implementer can set the duration of the first preset time period according to the actual situation, and it is not limited here. During the first preset time period, the system keeps the heater and motor driver in the off state and uses a surface temperature sensor to collect surface temperature data in real time at a fixed frequency (e.g., 10Hz) to obtain the surface temperature baseline change rate, so as to quantify the background temperature drift rate without active intervention. The method for obtaining the surface temperature baseline change rate is as follows: the difference between the surface temperature data at the end time and the initial time within the first preset time period is obtained as the first temperature change analysis value; the ratio of the first temperature change analysis value to the total duration of the first preset time period is used as the surface temperature baseline change rate. It should be noted that this embodiment assumes that the thermal drift rate caused by environmental factors is approximately constant within the first preset time period of a single test.

[0061] To establish a baseline zero point for evaluating subsequent temperature rise and impedance changes, the system needs to lock the battery's physical state at the start of energy injection. Therefore, in this embodiment, at the end of the first preset time period, the battery management system controls the motor controller to output a short-duration micro-pulse (e.g., a discharge pulse with an amplitude of 5A and a duration of 50ms). This pulse has extremely low energy, designed to excite the voltage response without causing an internal temperature rise in the battery. The system simultaneously acquires the voltage change and loop current at the pulse moment, where the voltage change is the difference in terminal voltage before and after the pulse is applied. Based on Ohm's law, i.e., the ratio of voltage change to loop current, the initial measured impedance of the battery module before heating is determined. At the same time, the system records the battery surface temperature reading at the end of the first preset time period, which is recorded as the initial surface temperature.

[0062] Because the power supply voltage of the substation inspection robot fluctuates with the battery charge, and the resistance of the heating element has a positive temperature coefficient, the heating power changes dynamically over time. Simply relying on the heating duration cannot accurately determine the total energy injected into the system. To ensure the accuracy of the subsequent thermal capacity model input, the system closes the heating loop and maintains it for a second preset duration. In this embodiment, the second preset duration is set to 30 seconds to ensure that the battery module receives sufficient heat to cause an observable temperature rise, while controlling the energy consumption of a single test. The implementer can set the size of the second preset duration according to the actual situation; no limitation is made here. During the closed heating loop period, the system synchronously collects the terminal voltage and loop current of the heating loop at a fixed period (e.g., 100ms) in real time. The product of the voltage and current at each moment is used as the reference power at the corresponding moment. The result of time integration of the reference power at all moments within the second preset duration is used as the accumulated heating energy, accurately reflecting the total Joule heat actually injected into the battery module and effectively eliminating measurement errors caused by power fluctuations. It should be noted that if the accumulated heating energy is less than the preset minimum energy threshold, the heating circuit is judged to be faulty, and an error is directly reported or the process is terminated. The preset minimum energy threshold is set by professionals according to the actual situation and is not limited here.

[0063] To obtain data reflecting the battery's true thermal response characteristics, the system needs to acquire the final state after heating. It should be noted that at the instant the heater is powered off, the local temperature on the battery surface may be artificially high due to residual heat from the heating wire (thermal overshoot), and direct acquisition will lead to data distortion. Therefore, in this embodiment, after the second preset duration, the heating circuit is disconnected, and a preset thermal relaxation duration is waited for. This thermal relaxation process aims to diffuse the accumulated heat on the surface of the heating element into the module and around the sensor, eliminating local hot spots. At the end of the preset thermal relaxation duration, the system again controls the motor controller to output a micropulse with the same parameters as the aforementioned short-duration micropulse. The system simultaneously acquires the voltage change and loop current at the current pulse moment, i.e., the end of the preset thermal relaxation duration. The ratio of the voltage change to the loop current at this time is determined as the measured termination impedance of the battery module; simultaneously, the battery surface temperature reading at this time is acquired, which is the termination surface temperature. In this embodiment, the preset thermal relaxation time is set to 10 seconds to ensure that the residual heat on the surface of the heating element has enough time to dissipate, so that the collected surface temperature can better represent the overall uniform temperature of the battery casing, rather than local hot spots. The implementer can set the preset thermal relaxation time according to the actual situation, and there is no limitation here.

[0064] It should be noted that the first preset time period, the second preset duration, and the preset thermal relaxation duration are consecutive. Furthermore, before starting this experimental procedure, the system initializes the current experiment's iteration count to 0.

[0065] Step S2: Based on the termination surface temperature, initial surface temperature, surface temperature reference change rate, and related duration, obtain the heating temperature rise value after eliminating environmental interference.

[0066] Specifically, the difference between the final surface temperature and the initial surface temperature collected in step S1 includes the temperature rise caused by the active energy injection from the heater and the natural temperature drift caused by environmental factors (such as air temperature changes, wind speed heat dissipation, etc.). In order to eliminate the interference of external environmental factors on the thermal response data and accurately obtain the pure temperature rise caused only by the active heating action, this embodiment obtains the heating-induced temperature rise value after removing environmental interference based on the final surface temperature, the initial surface temperature, the surface temperature reference change rate, and the relevant duration. This accurately characterizes the thermal response characteristics of the battery module to the accumulated heating energy, laying the foundation for the subsequent accurate calculation of the heat loss rate.

[0067] Preferably, in one feasible embodiment, the method for obtaining the heating-induced temperature rise is as follows: the difference between the termination surface temperature and the initial surface temperature is used as the actual temperature change value, accurately reflecting the overall temperature fluctuation during the entire test process; the sum of the second preset duration and the preset thermal relaxation duration is used as the reference duration, accurately reflecting the total time window in which environmental factors continuously act on the battery module; the product of the surface temperature reference change rate and the reference duration is used as the environmental reference temperature change value, accurately quantifying the natural temperature drift component caused only by the background environment (such as wind cooling and sunlight) within this time window; in order to eliminate environmental noise and separate the thermal response caused only by active heating excitation, the difference between the actual temperature change value and the environmental reference temperature change value is used as the heating-induced temperature rise value.

[0068] Step S3: Obtain the theoretical adiabatic temperature rise based on the accumulated heating energy, and obtain the convective heat loss rate based on the difference between the heating-induced temperature rise and the theoretical adiabatic temperature rise.

[0069] Specifically, considering that in a low-temperature, high-wind environment, some of the energy injected by the heater is carried away by environmental convection, resulting in a lower-than-expected actual temperature rise, this embodiment first obtains the theoretical adiabatic temperature rise value based on the accumulated heating energy to provide a physical benchmark for subsequent evaluation of the actual temperature rise efficiency. Then, based on the difference between the heating-induced temperature rise value and the theoretical adiabatic temperature rise value, the convective heat loss rate is obtained, which accurately reflects the degree of energy loss caused by the current environmental wind-cooling effect, and is beneficial for subsequent system judgment of the effectiveness of heating operation. Among them, the larger the convective heat loss rate, the stronger the environmental heat dissipation and the lower the heating efficiency.

[0070] Preferably, in one feasible embodiment of this method, the convective heat loss rate is obtained as follows: First, a preset static parameter needs to be retrieved from the non-volatile memory of the battery management system to obtain the preset total thermal capacity constant of the module, which is used to define the energy-temperature rise conversion coefficient of a specific model module under ideal dissipation-free operating conditions. The total thermal capacity constant of the module is determined based on the weighted sum of the product of the specific heat capacity and mass of each component within the battery module. It is a fixed value, usually calculated by the battery module manufacturer based on the material properties of each component, and is preset in the system memory, requiring no real-time measurement during the test. The accumulated heating energy represents the actual injected total heat energy. The ratio of the accumulated heating energy to the total thermal capacity constant of the module is then used as the theoretical adiabatic temperature rise value, accurately reflecting the theoretical upper limit of temperature rise that should be achieved under the assumption of no heat loss. To accurately characterize the loss ratio of the actual thermal response relative to the theoretical baseline, the ratio of the heating-induced temperature rise value to the theoretical adiabatic temperature rise value is negatively correlated and normalized, and used as the convective heat loss rate. Considering that the ratio of heating-induced temperature rise to theoretical adiabatic temperature rise ranges from 0 to 1, and because according to the law of conservation of energy, the actual temperature rise cannot exceed the theoretical upper limit of temperature rise under adiabatic conditions, and the direction of temperature rise should be consistent with the direction of energy injection, the result of subtracting the ratio of heating-induced temperature rise to theoretical adiabatic temperature rise from 1 is used as the result of negative correlation and normalization of the ratio of heating-induced temperature rise to theoretical adiabatic temperature rise.

[0071] Step S4: Obtain the thermal equilibrium reference impedance based on the termination surface temperature. Based on the deviation of the termination measured impedance from the thermal equilibrium reference impedance, and combined with the initial measured impedance, obtain the internal resistance response residual rate.

[0072] Specifically, considering that rapid heating in actual situations leads to a rapid increase in the battery surface temperature, while the internal electrolyte remains at a lower temperature due to thermal conduction lag, resulting in a state of high impedance with a hot surface and cold interior, this embodiment first obtains a thermal equilibrium reference impedance based on the termination surface temperature to accurately reflect the ideal low impedance benchmark assuming the battery's internal and external temperatures are the same. This is beneficial for subsequent evaluation of the lag magnitude of the actual impedance. Then, based on the deviation of the termination measured impedance from the thermal equilibrium reference impedance, combined with the initial measured impedance, the internal resistance response residual rate is obtained. This accurately reflects the lag degree of the internal electrolyte activity relative to the surface temperature indication, which is helpful for the system to identify false ready signals. A larger internal resistance response residual rate indicates a more severe heat transfer lag and lower battery activity.

[0073] Preferably, in one feasible embodiment, the method for obtaining the internal resistance response residual rate is as follows: First, a pre-calibrated thermal balance impedance lookup table is obtained by performing calibration tests on battery modules of the same model under constant temperature conditions in the laboratory, which is beneficial for constructing an accurate physical mapping relationship of the internal state; then, the corresponding thermal balance reference impedance is determined by querying the thermal balance impedance lookup table by the termination surface temperature; in order to characterize the absolute deviation of the actual impedance from the ideal reference, the difference between the termination measured impedance and the thermal balance reference impedance is taken as the first difference; the larger the first difference, the lower the internal temperature is than the surface temperature; in order to eliminate the influence of individual battery differences and initial state on the evaluation index and achieve normalized evaluation, the ratio of the first difference to the initial measured impedance is taken as the internal resistance response residual rate, ensuring that the value range of the internal resistance response residual rate is 0 to 1, because as heating proceeds, the termination measured impedance is less than the initial measured impedance and greater than the thermal balance reference impedance.

[0074] Step S5: Based on the convective heat loss rate and the internal resistance response residual rate, obtain the start-up control strategy of the battery module.

[0075] Specifically, the known convective heat loss rate accurately reflects the degree of energy loss caused by the external wind cooling effect, and the internal resistance response residual rate accurately reflects the degree of lag of the internal electrolyte activity relative to the surface temperature. Therefore, the specific thermal conditions of the current battery module (such as heat dissipation-dominated or heat transfer-lagging type) can be accurately analyzed by the convective heat loss rate and the internal resistance response residual rate. In order to maximize the task attendance rate while ensuring startup safety, this embodiment obtains the startup control strategy of the battery module based on the convective heat loss rate and the internal resistance response residual rate, ensuring that full-power startup is not forced when the internal components are not fully heated, and timely loss is stopped when external wind is strong and ineffective heating occurs, effectively improving the robot's environmental adaptability and operational reliability in low-temperature complex environments.

[0076] Preferably, in one feasible method of this embodiment, the method for obtaining the start-up control strategy is as follows: when the internal resistance response residual rate is less than or equal to the preset thermal hysteresis threshold, it indicates that the internal activity of the battery has met the requirements. At this time, the start-up control strategy is full-power start-up, which is beneficial to ensure the robot's full-task execution capability. When the internal resistance response residual rate is greater than the preset thermal hysteresis threshold, it indicates that the battery is in a low-temperature and high-resistance state. At this time, it is necessary to further judge the external environment and then judge whether the convective heat loss rate is greater than the preset heat loss threshold. If the convective heat loss rate is greater than the preset heat loss threshold, it indicates that the environmental heat dissipation is too strong and the benefit of continuing to heat is extremely low. At this time, the start-up control strategy is degraded start-up (stop-loss mode) to avoid ineffective consumption of precious battery power and failure to improve the battery state. If the convective heat loss rate is less than or equal to the preset heat loss threshold, it indicates that the heating is still effective. At this time, in order to further increase the internal temperature of the battery to reach the full-power start-up condition, the number of iterations of the current test is checked. Because under extreme low temperature conditions or when the heating system is aging, even if the environmental heat dissipation is not large, the internal temperature of the battery may increase extremely slowly. If there is no time limit for cyclic heating, the system will fall into a dead loop and exhaust the power.

[0077] If the number of iterations is less than the preset maximum number of iterations, it means that the system is still within the allowable preheating period. In this case, the control strategy is to maintain heating, increment the current iteration number by 1, and return to the step of acquiring surface temperature data, i.e., step S1 (cyclic preheating mode). The silent sampling within the first preset time period is re-executed to update the surface temperature reference change rate. Since environmental conditions such as wind speed may change over time, the environmental reference needs to be calibrated in real time to continue to improve the internal state using the remaining heat. If the number of iterations reaches the preset maximum number of iterations, it means that the preheating time has been exhausted or the heating system may have performance degradation. In order to avoid system deadlock and power depletion caused by falling into an infinite loop, the control strategy is to degrade the start-up.

[0078] It should be noted that the preset thermal hysteresis threshold, preset heat loss threshold, and preset maximum number of iterations were obtained through offline bench testing calibration. For example, the preset thermal hysteresis threshold was determined by testing the voltage drop during full-power startup of the battery under different internal resistance states to ensure that the voltage does not drop below the undervoltage protection point; the preset heat loss threshold was determined by evaluating the balance point between heater power and heat dissipation power under different wind speeds. This ensures that the threshold settings conform to the physical characteristics of the specific battery module model and the actual task requirements of the robot.

[0079] The method for obtaining degraded start-up is as follows: the difference between the voltage at the end of the preset thermal relaxation time and the minimum allowable operating voltage of the battery module is used as the limiting voltage, which accurately limits the voltage drop margin that the battery can utilize without triggering undervoltage protection, thus avoiding system power failure at startup; the ratio of the limiting voltage to the measured termination impedance is used as the reference current, which accurately reflects the theoretical limit current when only considering the voltage drop of ohmic internal resistance; in order to accurately address the risk of nonlinear increase in polarization internal resistance under high current, the product of the preset safety factor and the reference current is used as the maximum allowable current, which helps to leave a safety margin and avoid triggering undervoltage protection due to the actual terminal voltage drop exceeding the theoretical calculation value caused by the enhanced battery polarization effect during high current discharge; in order to ensure that the robot operates within the physical boundary of the battery's capacity, the maximum allowable current is sent to the robot's controller as the power limit boundary, and the robot is controlled to operate at the limited power, thereby avoiding shutdown due to voltage drop caused by high current startup. The minimum allowable operating voltage and preset safety factor of the battery module are obtained by querying the hardware protection parameters of the battery management system and analyzing the voltage response characteristics in historical low-temperature operation data, respectively, to ensure that the calculation results are practical for engineering applications.

[0080] In summary, this embodiment acquires the baseline surface temperature change rate, initial surface temperature, and initial measured impedance before heating; acquires the cumulative heating energy by closing the heating circuit; acquires the termination surface temperature and termination measured impedance by disconnecting the heating circuit; acquires the heating-induced temperature rise based on the termination surface temperature, initial surface temperature, and baseline surface temperature change rate; acquires the convective heat loss rate based on the cumulative heating energy and heating-induced temperature rise; acquires the internal resistance response residual rate based on the termination surface temperature, termination measured impedance, and initial measured impedance; and acquires the battery module's startup control strategy based on the convective heat loss rate and internal resistance response residual rate. This invention effectively solves the problem of startup crashes or ineffective heating caused by the inability to accurately assess battery status by acquiring the convective heat loss rate and internal resistance response residual rate, thus improving the robot's environmental adaptability.

[0081] Example 2:

[0082] This invention also proposes a low-temperature testing system for the battery module of a substation inspection robot; please refer to [link / reference]. Figure 2 The diagram shows a structural diagram of a low-temperature test system for a battery module of a substation inspection robot provided in an embodiment of the present invention. The system includes: a data acquisition module 10, a heating temperature rise acquisition module 20, a convective heat loss rate acquisition module 30, an internal resistance response residual rate acquisition module 40, and a data processing module 50.

[0083] The data acquisition module 10 is used to acquire surface temperature data of the battery module within a first preset time period before the heating circuit is closed, to calculate the surface temperature reference change rate, and to acquire the initial surface temperature and initial measured impedance of the battery module before heating; to close the heating circuit for a second preset time period, and to acquire the cumulative heating energy based on the voltage and current at each moment; and to acquire the termination surface temperature and termination measured impedance after disconnecting the heating circuit and waiting for a preset thermal relaxation time.

[0084] The heating temperature rise acquisition module 20 is used to acquire the heating temperature rise value after removing environmental interference based on the termination surface temperature, the initial surface temperature, the surface temperature reference change rate, and the relevant duration.

[0085] The convective heat loss rate acquisition module 30 is used to obtain the theoretical adiabatic temperature rise value based on the accumulated heating energy, and to obtain the convective heat loss rate based on the difference between the heating-induced temperature rise value and the theoretical adiabatic temperature rise value.

[0086] The internal resistance response residual rate acquisition module 40 is used to obtain the thermal equilibrium reference impedance based on the termination surface temperature, and to obtain the internal resistance response residual rate based on the deviation of the termination measured impedance from the thermal equilibrium reference impedance and the initial measured impedance.

[0087] The data processing module 50 is used to obtain the start-up control strategy of the battery module based on the convective heat loss rate and the internal resistance response residual rate.

[0088] It should be noted that the system provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the computer equipment can be divided into different functional modules to complete all or part of the functions described above. In addition, the low-temperature test system for the battery module of the substation inspection robot provided in the above embodiments and the low-temperature test method for the battery module of the substation inspection robot belong to the same concept. The specific implementation process is detailed in the method embodiments and will not be repeated here.

[0089] Example 3:

[0090] This invention also proposes a low-temperature testing device for the battery module of a substation inspection robot. This device includes a memory and a processor. The memory stores executable program code, and the processor calls and executes the executable program code to perform the low-temperature testing method for the battery module of the substation inspection robot provided in the embodiments of this application. Specifically, the device may be a chip, component, or module. The chip may include a connected processor and memory; the memory stores instructions, and when the processor calls and executes the instructions, the chip can perform the low-temperature testing method for the battery module of the substation inspection robot provided in the above embodiments.

[0091] In addition, this embodiment also protects a computer device; please refer to [link to relevant documentation]. Figure 3 The computer device includes a memory 401, a processor 402, and a computer program 403 stored in the memory 401 and running on the processor 402. When the processor 402 executes the computer program 403, the computer device can execute the aforementioned method for low-temperature testing of the battery module of any substation inspection robot.

[0092] Example 4:

[0093] The present invention also provides a computer-readable storage medium storing computer program code, which, when executed on a computer, causes the computer to perform the aforementioned method steps to implement the low-temperature testing method for the battery module of the substation inspection robot provided in the above embodiments.

[0094] Example 5:

[0095] The present invention also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned related steps to implement the low-temperature testing method for the battery module of the substation inspection robot provided in the above embodiments.

[0096] In this embodiment, the device, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0097] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0098] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A low-temperature test method for the battery module of a substation inspection robot, characterized in that, The method includes the following steps: Before the heating circuit is closed, the surface temperature data of the battery module within a first preset time period is obtained to calculate the surface temperature reference change rate, and the initial surface temperature and initial measured impedance of the battery module before heating are obtained; the heating circuit is closed for a second preset time period, and the accumulated heating energy is obtained according to the voltage and current at each moment; after the heating circuit is disconnected and a preset thermal relaxation time is waited, the termination surface temperature and termination measured impedance are obtained. Based on the termination surface temperature, initial surface temperature, surface temperature baseline change rate and related duration, the heating temperature rise value after eliminating environmental interference is obtained. The theoretical adiabatic temperature rise is obtained based on the accumulated heating energy, and the convective heat loss rate is obtained based on the difference between the heating-induced temperature rise and the theoretical adiabatic temperature rise. The thermal equilibrium reference impedance is obtained based on the termination surface temperature. The internal resistance response residual rate is obtained by combining the deviation of the termination measured impedance from the thermal equilibrium reference impedance with the initial measured impedance. Based on the convective heat loss rate and the internal resistance response residual rate, the start-up control strategy of the battery module is obtained. The method for obtaining the heating-induced temperature rise is as follows: The difference between the final surface temperature and the initial surface temperature is taken as the actual temperature change value; The sum of the second preset duration and the preset thermal relaxation duration is used as the reference duration. The product of the surface temperature reference rate of change and the reference duration is used as the change value of the ambient reference temperature. The difference between the actual temperature change and the ambient reference temperature change is taken as the heating-induced temperature rise. The method for obtaining the residual rate of the internal resistance response is as follows: Obtain the preset thermal balance impedance lookup table, and determine the corresponding thermal balance reference impedance by querying the thermal balance impedance lookup table through the termination surface temperature. The difference between the measured impedance at termination and the thermal equilibrium reference impedance is taken as the first difference; The ratio of the first difference to the initial measured impedance is taken as the internal resistance response residual rate. The method for obtaining the startup control strategy is as follows: When the internal resistance response residual rate is less than or equal to the preset thermal hysteresis threshold, the start-up control strategy is full-power start-up; When the internal resistance response residual rate is greater than the preset thermal hysteresis threshold, it is determined whether the convective heat loss rate is greater than the preset heat loss threshold. If the convective heat loss rate is greater than the preset heat loss threshold, the control strategy will be degraded startup. If the convective heat loss rate is less than or equal to the preset heat loss threshold, then check the number of iterations in the current test. If the number of iterations is less than the preset maximum number of iterations, the control strategy is to maintain heating and return to the step of acquiring surface temperature data; If the number of iterations reaches the preset maximum number of iterations, the start control strategy will be degraded startup.

2. The low-temperature test method for the battery module of the substation inspection robot as described in claim 1, characterized in that, The method for obtaining the convective heat loss rate is as follows: Obtain the preset total heat capacity constant of the module; wherein, the total heat capacity constant of the module is determined based on the weighted sum of the product of the specific heat capacity and mass of each component in the battery module; The ratio of the accumulated heating energy to the total heat capacity constant of the module is used as the theoretical adiabatic temperature rise value. The result of negatively correlating and normalizing the ratio of the heating-induced temperature rise to the theoretical adiabatic temperature rise is taken as the convective heat loss rate.

3. The low-temperature test method for the battery module of the substation inspection robot as described in claim 1, characterized in that, The method for obtaining the downgraded startup is as follows: The difference between the voltage at the end of the preset thermal relaxation time and the minimum allowable operating voltage of the battery module is used as the limiting voltage. The ratio of the defined voltage to the measured termination impedance is used as the reference current; The product of the preset safety factor and the reference current is taken as the maximum allowable current; The maximum allowable current is sent as a power limit boundary to the robot's controller, which then controls the robot to operate at the limited power.

4. The low-temperature test method for the battery module of the substation inspection robot as described in claim 1, characterized in that, The method for obtaining the initial measured impedance and the final measured impedance is as follows: An electrical pulse of preset amplitude is applied to the battery module, and the voltage change and loop current at the pulse moment are collected; the voltage change is the difference between the terminal voltages before and after the pulse is applied. The ratio of the voltage change to the loop current is used as the measured impedance.

5. The low-temperature test method for the battery module of the substation inspection robot as described in claim 1, characterized in that, The method for obtaining the surface temperature reference change rate is as follows: The difference between the surface temperature data at the end time and the initial time within the first preset time period is obtained as the first temperature change analysis value. The ratio of the first temperature change analysis value to the total duration of the first preset time period is used as the baseline change rate of surface temperature.

6. The low-temperature test method for the battery module of the substation inspection robot as described in claim 1, characterized in that, The method for obtaining the accumulated heating energy is as follows: Obtain the product of voltage and current at each moment within the second preset time period, and use it as the reference power at the corresponding moment. The result of integrating the reference power at all times within the second preset time period is taken as the cumulative heating energy.

7. A low-temperature testing system for the battery module of a substation inspection robot, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the low-temperature test method for the battery module of the substation inspection robot according to any one of claims 1-6.

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