Brake resistor box braking energy recovery monitoring optimization method

Abstract

This invention relates to the field of braking energy recovery technology and discloses a method for monitoring and optimizing braking energy recovery in a braking resistor box. The method includes: first, acquiring the surface temperature of the braking resistor box, ambient temperature, and braking electrical parameters using sensors. To address the thermal response hysteresis problem, a nonlinear mapping of the fundamental delay time constant is performed using energy density to derive the delay coefficient and its weight. To address sensor noise interference, a phase space gated multiplier is constructed using the time difference of the surface temperature combined with the delay coefficient to calculate noise suppression parameters. Subsequently, the equivalent coefficient of dynamic convection heat transfer is extracted in real time based on the law of energy conservation. On this basis, the transient heat capacity absorption and real-time heat dissipation are decoupled through an extreme emergency braking time window to calculate the safe carrying power. Finally, a nonlinear smoothing function is used to map the excess power into a recovery activation coefficient, realizing the distribution of braking power between the resistor box and the recovery module.

Description

Technical Field

[0001] This invention relates to the field of braking energy recovery technology, specifically to an optimization method for monitoring braking energy recovery in a braking resistor box. Background Technology

[0002] With the development of new energy vehicles and industrial drive systems, regenerative braking technology has become crucial for improving energy efficiency. In regenerative braking systems, the braking resistor box, as the hardware that absorbs residual braking energy, directly affects the system's safety and the upper limit of energy recovery. Currently, common regenerative braking schemes often use fixed temperature thresholds or static thermodynamic models for monitoring. In actual operating scenarios, the braking resistor box operates in a complex dynamic environment, and existing technologies still have several unresolved issues. First, the braking process involves a dramatic energy injection, resulting in a significant time lag in heat transfer from the resistance wire to the sensor housing. When braking energy density fluctuates rapidly, the temperature signal collected by the sensor cannot reflect the transient internal thermal state in real time. This heat conduction delay causes time-domain distortion in the monitoring data, making it difficult for the system to make accurate judgments immediately. Second, the raw data collected by the sensor often contains high-frequency electromagnetic noise. When calculating the rate of temperature change over time to assess heat dissipation trends, numerical differentiation significantly amplifies this noise. Existing technologies typically use simple moving average filtering, but this further increases phase delay, leading to severe lag and bias in the monitoring results during dynamic response. In scenarios requiring real-time distribution of braking energy, unstable rate-of-change signals can lead to frequent fluctuations in regenerative power. Furthermore, the heat dissipation capacity of the braking resistor box is significantly affected by the external convection environment. Existing thermodynamic models are mostly based on fixed heat dissipation coefficients, but during vehicle movement or changes in ventilation conditions, the external convective heat transfer coefficient exhibits highly nonlinear characteristics. Static models cannot extract the current real-time heat dissipation boundary, causing the predicted safe power value to deviate from the actual physical state, resulting in either insufficient energy recovery or overheating and damage to the resistor box. Finally, balancing the absorption capacity of the braking resistor box with the receiving capacity of the regenerative module is a challenge during braking energy distribution. Existing solutions often employ hard cutoff or jump-type distribution logic when the braking power exceeds the resistor box's carrying capacity. This power distribution method causes abrupt changes in the input power of the energy recovery module, impacting the onboard power grid or energy storage components. Under uncommon high-frequency braking conditions, these problems are coupled together, not only reducing the energy recovery rate but also increasing the risk of hardware system damage.

[0003] In summary, there is a need for a braking resistor box monitoring and optimization method that can compensate for heat conduction delay, suppress high-frequency noise interference, invert heat dissipation boundary in real time, and achieve smooth power distribution. Summary of the Invention

[0004] This invention provides an optimized method for monitoring and controlling the regenerative braking energy of a braking resistor box, which helps to solve the problems mentioned in the background art.

[0005] This invention provides the following technical solution: a method for monitoring and optimizing the regenerative braking energy of a braking resistor box, comprising:

[0006] The temperature difference is calculated by subtracting the surface temperature of the braking resistor box from the ambient temperature.

[0007] The braking power is calculated by multiplying the braking voltage and the braking current, and the energy density is calculated by dividing the braking power by the surface area of ​​the braking resistor box.

[0008] The delay coefficient is calculated by exponentially decaying the basic delay time constant using energy density, and then converted into a delay weight by combining the sampling interval.

[0009] The initial temperature change rate is calculated using the time difference of surface temperature, and the noise suppression parameters are calculated by combining the delay coefficient and the temperature difference.

[0010] The optimal temperature change rate is obtained by multiplying the delay weight and noise suppression parameter into the initial temperature change rate, and the dynamic equivalent coefficient of convective heat transfer is calculated by combining energy conservation.

[0011] The transient heat absorption limit power is calculated using specific heat capacity, mass, temperature difference, and extreme emergency braking time window, and then superimposed with the real-time convection heat dissipation limit power to calculate the safe load-bearing power.

[0012] The excess power is calculated by subtracting the safe load power from the braking power, and the recovery activation coefficient is obtained by mapping through a nonlinear smoothing function.

[0013] The command power of the recovery module is calculated by multiplying the braking power by the recovery activation coefficient, and the remaining power after deducting the command value is used as the command power output of the resistor box.

[0014] Optionally, the step of calculating the temperature difference by subtracting the surface temperature of the braking resistor box from the ambient temperature includes:

[0015] Obtain the surface temperature of the braking resistor box and the ambient temperature;

[0016] The temperature difference is obtained by subtracting the ambient temperature from the obtained surface temperature of the braking resistor box.

[0017] Optionally, the step of multiplying the braking voltage and braking current to calculate the braking power, and then dividing the braking power by the surface area of ​​the braking resistor box to calculate the energy density, includes:

[0018] Obtain the braking voltage and braking current;

[0019] The braking power is obtained by multiplying the obtained braking voltage by the braking current.

[0020] Obtain the surface area of ​​the braking resistor box;

[0021] The energy density is obtained by dividing the braking power by the surface area of ​​the braking resistor box.

[0022] Optionally, the step of calculating the delay coefficient by performing an exponential decay operation on the basic delay time constant using energy density, and converting it into a delay weight by combining the sampling interval, includes:

[0023] Set the basic delay time constant and the reference energy density;

[0024] Divide the energy density by the reference energy density, and take the negative value of the result of the division as the exponent for natural exponentiation.

[0025] The delay coefficient is obtained by multiplying the result of the natural exponent calculation by the basic delay time constant.

[0026] Set the sampling time interval;

[0027] The delay weight is obtained by dividing the sampling time interval by the sum of the sampling time interval and the delay coefficient.

[0028] Optionally, the step of calculating the initial temperature change rate using the time difference of surface temperature and calculating the noise suppression parameters by combining the delay coefficient and the temperature difference includes:

[0029] Obtain the surface temperature of the braking resistor box at the previous moment;

[0030] Subtracting the previous moment's surface temperature from the surface temperature of the braking resistor box yields the temperature change difference.

[0031] Divide the temperature change difference by the sampling time interval to obtain the initial temperature change rate;

[0032] Set a small positive constant;

[0033] Multiply the initial temperature change rate by the delay coefficient to obtain the product result;

[0034] Add the temperature difference to the small positive constant to obtain the summation result;

[0035] Divide the product by the sum and calculate the absolute value of the division.

[0036] The absolute value is then negative and used as the exponent for natural exponentiation.

[0037] The noise suppression parameter is obtained by subtracting the result of the natural exponent calculation from the numerical value.

[0038] Optionally, the step of multiplying the delay weight and noise suppression parameter into the initial temperature change rate to obtain the optimized temperature change rate, and calculating the dynamic equivalent coefficient of convective heat transfer in combination with energy conservation, includes:

[0039] The optimized temperature change rate is obtained by multiplying the initial temperature change rate, the delay weight, and the noise suppression parameter.

[0040] Obtain the specific heat capacity and mass of the braking resistor box;

[0041] The heat absorption parameters are obtained by multiplying the specific heat capacity of the braking resistor box, the mass of the braking resistor box, and the optimized temperature change rate.

[0042] Subtracting the heat absorption parameter from the braking power yields the convective heat transfer term;

[0043] Multiply the surface area of ​​the braking resistor box by the temperature difference, and add the result of the multiplication to the small positive constant to obtain the denominator term of the convective heat transfer.

[0044] Dividing the numerator of the convective heat transfer by the denominator of the convective heat transfer yields the dynamic equivalent coefficient of the convective heat transfer.

[0045] Optionally, the step of calculating the transient heat absorption limit power using specific heat capacity, mass, temperature difference, and the extreme emergency braking time window, and then superimposing it with the real-time convection heat dissipation limit power to calculate the safe load-bearing power, includes:

[0046] Set the maximum permissible temperature and the extreme emergency braking time window;

[0047] Subtracting the surface temperature of the braking resistor box from the maximum allowable temperature yields the temperature margin difference.

[0048] The maximum heat absorption is obtained by multiplying the specific heat capacity of the braking resistor box, the mass of the braking resistor box, and the temperature margin difference.

[0049] Divide the ultimate heat absorption by the ultimate emergency braking time window to obtain the transient heat capacity heat absorption ultimate power;

[0050] Multiply the convective heat transfer dynamic equivalent coefficient, the surface area of ​​the braking resistor box, and the temperature margin difference to obtain the real-time convective heat dissipation limit power.

[0051] The safe load-bearing power of the braking resistor box is obtained by adding the real-time convection heat dissipation limit power to the transient heat capacity heat absorption limit power.

[0052] Optionally, the step of calculating the excess power by subtracting the safe load power from the braking power and obtaining the recovery activation coefficient through a nonlinear smoothing function includes:

[0053] The excess power is obtained by subtracting the safe bearing power of the braking resistor box from the braking power.

[0054] Set the shape factor and reference power;

[0055] Divide the excess power by the reference power, and multiply the result of the division by the shape factor;

[0056] The negative value of the multiplication result is used as the exponent for natural exponentiation.

[0057] Add the result of the natural exponent calculation to the numerical value to obtain the activated denominator term;

[0058] Divide the value by the activation denominator to obtain the recycling activation coefficient.

[0059] Optionally, the step of calculating the command power of the recovery module by multiplying the braking power by the recovery activation coefficient, and using the remaining power after deducting the command value as the command power output of the resistor box, includes:

[0060] Multiplying the braking power by the recovery activation coefficient yields the power of the guiding energy recovery module;

[0061] The power of the guided energy recovery module is output as the final control command;

[0062] Subtracting the power of the guiding energy recovery module from the braking power yields the power of the guiding braking resistor box.

[0063] The power of the guide braking resistor box is output as the final control command.

[0064] The present invention has the following beneficial effects:

[0065] 1. By acquiring fundamental physical quantities such as the surface temperature of the braking resistor box, ambient temperature, and braking voltage and current, this solution constructs an optimized processing flow for braking energy recovery monitoring in dynamic braking environments with frequent and drastic changes. Under these specific conditions, braking energy is injected into the resistor box at high frequency, and there is a physical time lag in the heat transfer from the heating element to the surface sensor. This causes conventional static thermodynamic monitoring models to fail to reflect the transient thermal state of the equipment synchronously. Furthermore, the acquired surface temperature signal is often accompanied by high-frequency electrical noise; directly using time difference differentiation amplifies the interference signal, distorting the temperature change trend. Additionally, when the input braking power exceeds the resistor box's tolerance limit, conventional hard cut-off or abrupt allocation strategies can cause energy flow jumps, impacting subsequent energy storage devices or the vehicle's power grid. To address these issues, this solution uses energy density to exponentially decay the fundamental delay time constant to calculate the delay weight, and combines this with temperature difference calculations to construct noise suppression parameters, making the acquired temperature change rate data closer to the actual physical heating trend. Subsequently, the scheme derives the dynamic equivalent coefficient of convective heat transfer based on energy conservation and introduces an extreme emergency braking time window to decouple and superimpose the transient heat absorption capacity and real-time heat dissipation capacity, thereby obtaining a safe carrying power that conforms to dynamic changes. Finally, the scheme uses a nonlinear smoothing function to map the excess power exceeding the safe carrying range, obtaining a continuously adjustable recovery activation coefficient, thereby achieving flexible distribution of braking power between the resistor box and the energy recovery module. This process mitigates the system impact caused by hard power switching, improves the stability of dynamic braking energy distribution, and helps maintain the operational safety of the braking resistor box under nonlinear convective heat dissipation and variable braking conditions.

[0066] 2. By acquiring the surface temperature of the braking resistor box and the ambient temperature, and subtracting the two to extract the temperature difference, a thermodynamic gradient benchmark between the entire energy recovery system and the external cooling medium was constructed. In actual industrial and vehicle operation scenarios, the ambient temperature of the equipment usually fluctuates significantly with seasonal changes, day-night cycles, and geographical location shifts. If the monitoring system relies solely on the absolute temperature of the braking resistor box surface to determine the overheating state and safety boundary of the equipment, it may easily overlook the actual cooling potential changes of the external cold source. By directly acquiring the temperatures at two key locations and calculating the difference, the system can objectively reflect the temperature gradient between the equipment body and the external cooling medium at a specific moment. The actual physical potential energy of the surrounding environment dissipates and accumulates heat; this thermodynamic state assessment mechanism based on dynamic temperature difference eliminates the applicability limitations of a single absolute temperature benchmark under different climate and ventilation conditions; it provides a fundamental driving force input that conforms to the macroscopic laws of heat transfer for subsequent deduction of complex heat conduction networks and convective heat transfer intensity; it enables the monitoring algorithm system to have adaptive dynamic adjustment characteristics for variable external climate features; it avoids the risk of overestimating the heat capacity of equipment due to low absolute temperature in frigid environments, or prematurely triggering the system overheat protection action due to high initial temperature in hot environments; thus improving the objectivity of the braking system thermal state assessment and the reliability of monitoring and early warning.

[0067] 3. By synchronously acquiring braking voltage and braking current, multiplying them to obtain transient braking power, and then dividing it by the pre-acquired surface area of ​​the braking resistor box to obtain energy density, a quantitative index for the intensity of electromechanical energy conversion to thermal energy was established. During braking under frequent changing operating conditions, the voltage and current signals at the bus end exhibit high-frequency fluctuations and unsteady-state characteristics. Directly using this overall electrical power as an evaluation parameter for thermal shock makes it difficult to measure the actual thermal stress concentration per unit area of ​​material. Distributing the instantaneously generated total braking power to the effective heat dissipation surface area of ​​the equipment achieves spatial normalization of the electromagnetic energy injection intensity. This calculation method… This formula transforms abstract overall electrical parameters into specific physical parameters that characterize the intensity of localized heating of materials; it enables lateral comparison and unified monitoring of braking resistor boxes with different volume specifications or physical dimensions under the same energy density scale; it provides a spatially relevant reference for subsequent evaluation of the heat conduction hysteresis effect caused by high-frequency braking energy inside the equipment; it avoids power evaluation deviations caused by differences in equipment size; it helps to capture the physical trend of rapid heat accumulation in local areas in the early stage of braking, improves the system's sensitivity to nonlinear thermal shock states, and enhances its universal adaptability to different hardware structures.

[0068] 4. By dividing the real-time calculated energy density by a preset reference energy density, and taking the negative of the result to perform a natural exponential operation, and then multiplying it by the basic delay time constant to obtain a delay coefficient, and then combining it with the sampling time interval to convert it into a delay weight, a dynamic compensation mechanism for unsteady-state heat conduction processes is established. In the physical characteristics of heat conduction within solid materials, there is an inherent time lag in the transfer of heat from the internal heating core to the external surface sensor; and this lag time is not constant. When the externally injected braking energy density increases sharply, the thermodynamic gradient formed inside the material will become steeper, macroscopically accelerating the heat transfer response rate, which manifests as a faster actual physical response. The theoretical delay time is shortened; the mathematical form of a negative exponential function is used to attenuate and correct the basic delay time constant, objectively fitting the objective law of the nonlinear decrease of thermal conduction resistance under high energy input conditions; the abstract delay time constant is fused with the system's sampling time interval and converted into a dimensionless delay weight, so that the physical delay characteristics in the continuous time domain can be smoothly mapped to the discrete digital sampling control cycle; this processing action alleviates the problem of temperature signal measurement lag caused by sensor installation location; it ensures that the thermal state change information obtained in subsequent algorithms can correspond to the actual physical thermal shock events on the time axis, enhancing the synchronization of transient monitoring data in the time domain.

[0069] 5. By extracting the temperature from the previous moment and performing finite difference calculations to obtain the initial temperature change rate, and then multiplying this rate by the delay coefficient and dividing by the temperature difference with a small positive constant, the noise suppression parameter is finally obtained after taking the absolute value and performing calculations with the negative natural exponent. This constructs a dynamic filtering model with spatiotemporal adaptive adjustment capabilities. In industrial environments, the analog signals collected by temperature sensors are easily affected by high-frequency interference from electromagnetic radiation from high-voltage buses. Traditional monitoring systems, when directly performing time difference derivatives on temperature signals with small fluctuations, will drastically amplify these electrical noises, causing the calculated rate of change to oscillate violently. The temperature change rate of the late characteristic forms a ratio with the macroscopic temperature difference, constructing a phase space mapping constraint mechanism. When the detected minute temperature fluctuations are caused by high-frequency physical noise, this mathematical structure can output a very small gating value to suppress the fluctuations. When the equipment suffers actual braking thermal shock and generates a real temperature rise, the operation process releases the filtering constraints. This nonlinear numerical processing operation achieves the preservation of useful low-frequency physical trends and the suppression of high-frequency interference noise without introducing a long sliding window. It improves the smoothing quality of the original temperature derivative signal and reduces the probability of the system triggering malfunctions due to sudden changes in electrical noise.

[0070] 6. By sequentially multiplying the initial temperature change rate by the previously calculated delay weights and noise suppression parameters to obtain the optimized temperature change rate, and combining specific heat capacity, mass, braking power, and temperature difference, the dynamic equivalent coefficient of convective heat transfer is calculated according to the energy balance law, realizing the dynamic inversion of complex convective heat dissipation boundary conditions. During actual vehicle operation, the air velocity, wind direction, and operating state of the cooling fan outside the braking resistor box are constantly changing dynamically. Traditional thermodynamic models relying on a fixed heat dissipation coefficient cannot truly characterize this nonlinear convective heat dissipation process. Combining the noise-resistant and time-delay-compensated temperature change rate with the inherent heat capacity properties of the equipment, it is possible to... It can accurately quantify the actual sensible heat absorption of the equipment's material at the current moment; then, by subtracting this heat absorption portion from the total braking input power, the remaining energy is the heat power dissipated to the external environment at the current moment; the equivalent heat dissipation coefficient derived from this reduces the need for complex measurement of external fluid dynamic parameters, and directly extracts the macroscopic cooling efficiency index from the system's own electrothermal response performance; this inversion mechanism based on the law of conservation of energy enables the system to adapt to random fluctuations in external cooling conditions in real time; it provides heat dissipation capacity parameters that fit the actual physical conditions for the subsequent delineation of the safe power boundary, and improves the equipment's state tracking capability in unsteady heat dissipation environments.

[0071] 7. By setting the maximum allowable temperature and calculating the difference between the surface temperature of the braking resistor box, the temperature margin difference is obtained. Combined with physical properties and the extreme emergency braking time window, the transient heat capacity absorption limit power is calculated, and this is added to the real-time convection heat dissipation limit power to obtain the final safe bearing power of the braking resistor box. A bearing boundary evaluation model that decouples steady-state heat dissipation and transient heat storage is established. When facing sudden extreme continuous braking conditions, the braking resistor box not only relies on external cold air convection to remove heat, but its own large physical mass and material specific heat capacity also play a role in heat energy buffering. Evaluating the system safety boundary based solely on the current heat dissipation capacity will underestimate the short-term impact resistance potential of large-mass equipment. By introducing a limit braking time window as a constraint, the maximum heat that the equipment can absorb within the allowable temperature margin is reasonably converted from the energy dimension to the power dimension. This transient heat absorption extreme value, representing the material's thermal capacity buffering capacity, is then linearly superimposed with the previously obtained real-time convective heat dissipation extreme value. This combined calculation method restores the physical process of heat absorption of macroscopic objects under severe thermal shock. As a result, the final safe load-bearing power index not only encompasses the current cooling state of the system but also taps into the latent heat absorption margin of the hardware. This avoids the waste of braking energy absorption capacity caused by overly conservative system settings and improves the rationality and physical objectivity of the energy recovery safety boundary prediction.

[0072] 8. By subtracting the safe bearing power from the real-time braking power to obtain the excess power, and then dividing the excess power by the set reference power and combining it with the shape factor, a nonlinear smooth mapping relationship is constructed using natural exponential calculation. Finally, a recovery activation coefficient is output, thus constructing a flexible switching filtering buffer layer for braking energy exceeding the bearing capacity. In conventional energy management strategies, when the input power is detected to exceed the system safety limit, a relay-type hard cutoff or a step-type direct allocation logic is typically used. This operation causes a large amount of braking energy to change direction in a very short time, triggering electrical discharges in the vehicle's electrical grid or energy storage battery network. Voltage and current surges are mitigated; a smoothing function is introduced to perform a nonlinear exponential mapping on excess power crossing the safety boundary, resulting in a mathematical characteristic of continuous and smooth transition of the calculated distribution coefficient within the range of zero and one; by adjusting the mapping shape and reference base, the sensitive area and conversion rate of power transfer can be flexibly configured; this mechanism eliminates abrupt abrupt changes in energy transfer control commands; it makes the distribution of braking power smoother; it alleviates the impact of transient high-power transfer on the insulation and lifespan of surrounding electrical hardware, and improves the electrical stability and control compliance of the braking energy recovery network under extreme over-limit conditions.

[0073] 9. By multiplying the total braking power by the previously obtained continuous recovery activation coefficient, the control power of the guiding energy recovery module is calculated separately. The remaining value after deducting the recovery part from the total braking power is used as the command power of the resistor box for synchronous output, thus completing the global conservation and coordinated allocation of energy multi-path redirection. When facing high-frequency changing compound braking scenarios, it is necessary to take into account both the thermodynamic safety bottom line of the underlying hardware and the energy recovery and utilization efficiency of the whole vehicle. Through this multiplicative allocation and addition-subtraction difference command issuance method, it is ensured that the mathematical sum of the two split power paths is strictly equal to the actual total braking power generated instantaneously at the front end. This calculation output step based on energy conservation logic avoids the situation of command superposition overflow or value loss in the power command allocation stage. It allows the excess heat energy that exceeds the dynamic bearing limit of the braking resistor box to be smoothly guided to the energy recovery module for secondary utilization. The remaining braking power within the safe range continues to be absorbed and dissipated by the resistor box. This allocation mechanism, under the premise of ensuring that the heat-generating components operate within the physical safety range, schedules the flow of excess braking energy, improves the integrity of energy management and the orderliness of resource allocation in the electromechanical system. Attached Figure Description

[0074] Figure 1 This is a schematic diagram of the basic process of the present invention.

[0075] Figure 2 This is a flowchart of the system initialization and perception link construction process of the present invention.

[0076] Figure 3This is a flowchart of the thermodynamic state sensing and heat dissipation coefficient inversion process of the present invention.

[0077] Figure 4 This is a flowchart of the safety boundary prediction and energy command issuance of the present invention. Detailed Implementation

[0078] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0079] Example 1, refer to Figure 1 A method for monitoring and optimizing the braking energy recovery of a braking resistor box, comprising:

[0080] The temperature difference is calculated by subtracting the surface temperature of the braking resistor box from the ambient temperature.

[0081] The braking power is calculated by multiplying the braking voltage and the braking current, and the energy density is calculated by dividing the braking power by the surface area of ​​the braking resistor box.

[0082] The delay coefficient is calculated by exponentially decaying the basic delay time constant using energy density, and then converted into a delay weight by combining the sampling interval.

[0083] The initial temperature change rate is calculated using the time difference of surface temperature, and the noise suppression parameters are calculated by combining the delay coefficient and the temperature difference.

[0084] The optimal temperature change rate is obtained by multiplying the delay weight and noise suppression parameter into the initial temperature change rate, and the dynamic equivalent coefficient of convective heat transfer is calculated by combining energy conservation.

[0085] The transient heat absorption limit power is calculated using specific heat capacity, mass, temperature difference, and extreme emergency braking time window, and then superimposed with the real-time convection heat dissipation limit power to calculate the safe load-bearing power.

[0086] The excess power is calculated by subtracting the safe load power from the braking power, and the recovery activation coefficient is obtained by mapping through a nonlinear smoothing function.

[0087] The command power of the recovery module is calculated by multiplying the braking power by the recovery activation coefficient, and the remaining power after deducting the command value is used as the command power output of the resistor box.

[0088] The step of calculating the temperature difference by subtracting the surface temperature of the braking resistor box from the ambient temperature includes:

[0089] Obtain the surface temperature of the braking resistor box and the ambient temperature;

[0090] The temperature difference is obtained by subtracting the ambient temperature from the obtained surface temperature of the braking resistor box.

[0091] The step of multiplying the braking voltage and braking current to calculate the braking power, and then dividing the braking power by the surface area of ​​the braking resistor box to calculate the energy density, includes:

[0092] Obtain the braking voltage and braking current;

[0093] The braking power is obtained by multiplying the obtained braking voltage by the braking current.

[0094] Obtain the surface area of ​​the braking resistor box;

[0095] The energy density is obtained by dividing the braking power by the surface area of ​​the braking resistor box.

[0096] The step of calculating the delay coefficient by exponentially decaying the basic delay time constant using energy density, and then converting it into a delay weight by combining the sampling interval, includes:

[0097] Set the basic delay time constant and the reference energy density;

[0098] Divide the energy density by the reference energy density, and take the negative value of the result of the division as the exponent for natural exponentiation.

[0099] The delay coefficient is obtained by multiplying the result of the natural exponent calculation by the basic delay time constant.

[0100] Set the sampling time interval;

[0101] The delay weight is obtained by dividing the sampling time interval by the sum of the sampling time interval and the delay coefficient.

[0102] The initial temperature change rate is calculated using the time difference of surface temperature, and noise suppression parameters are calculated by combining the delay coefficient and the temperature difference, including:

[0103] Obtain the surface temperature of the braking resistor box at the previous moment;

[0104] Subtracting the previous moment's surface temperature from the surface temperature of the braking resistor box yields the temperature change difference.

[0105] Divide the temperature change difference by the sampling time interval to obtain the initial temperature change rate;

[0106] Set a small positive constant;

[0107] Multiply the initial temperature change rate by the delay coefficient to obtain the product result;

[0108] Add the temperature difference to the small positive constant to obtain the summation result;

[0109] Divide the product by the sum and calculate the absolute value of the division.

[0110] The absolute value is then negative and used as the exponent for natural exponentiation.

[0111] The noise suppression parameter is obtained by subtracting the result of the natural exponent calculation from the numerical value.

[0112] The process of multiplying the delay weight and noise suppression parameter into the initial temperature change rate to obtain the optimized temperature change rate, and then calculating the dynamic equivalent coefficient of convective heat transfer in conjunction with energy conservation, includes:

[0113] The optimized temperature change rate is obtained by multiplying the initial temperature change rate, the delay weight, and the noise suppression parameter.

[0114] Obtain the specific heat capacity and mass of the braking resistor box;

[0115] The heat absorption parameters are obtained by multiplying the specific heat capacity of the braking resistor box, the mass of the braking resistor box, and the optimized temperature change rate.

[0116] Subtracting the heat absorption parameter from the braking power yields the convective heat transfer term;

[0117] Multiply the surface area of ​​the braking resistor box by the temperature difference, and add the result of the multiplication to the small positive constant to obtain the denominator term of the convective heat transfer.

[0118] Dividing the numerator of the convective heat transfer by the denominator of the convective heat transfer yields the dynamic equivalent coefficient of the convective heat transfer.

[0119] The calculation of the transient heat absorption limit power using specific heat capacity, mass, temperature difference, and extreme emergency braking time window, and the superposition of this power with the real-time convection heat dissipation limit power to calculate the safe load-bearing power, includes:

[0120] Set the maximum permissible temperature and the extreme emergency braking time window;

[0121] Subtracting the surface temperature of the braking resistor box from the maximum allowable temperature yields the temperature margin difference.

[0122] The maximum heat absorption is obtained by multiplying the specific heat capacity of the braking resistor box, the mass of the braking resistor box, and the temperature margin difference.

[0123] Divide the ultimate heat absorption by the ultimate emergency braking time window to obtain the transient heat capacity heat absorption ultimate power;

[0124] Multiply the convective heat transfer dynamic equivalent coefficient, the surface area of ​​the braking resistor box, and the temperature margin difference to obtain the real-time convective heat dissipation limit power.

[0125] The safe load-bearing power of the braking resistor box is obtained by adding the real-time convection heat dissipation limit power to the transient heat capacity heat absorption limit power.

[0126] The process of calculating the excess power by subtracting the safe load power from the braking power, and then mapping it using a nonlinear smoothing function to obtain the recovery activation coefficient, includes:

[0127] The excess power is obtained by subtracting the safe bearing power of the braking resistor box from the braking power.

[0128] Set the shape factor and reference power;

[0129] Divide the excess power by the reference power, and multiply the result of the division by the shape factor;

[0130] The negative value of the multiplication result is used as the exponent for natural exponentiation.

[0131] Add the result of the natural exponent calculation to the numerical value to obtain the activated denominator term;

[0132] Divide the value by the activation denominator to obtain the recycling activation coefficient.

[0133] The process of calculating the recovery module's command power by multiplying the braking power by the recovery activation coefficient, and then using the remaining power after deducting this command value as the resistor box's command power output, includes:

[0134] Multiplying the braking power by the recovery activation coefficient yields the power of the guiding energy recovery module;

[0135] The power of the guided energy recovery module is output as the final control command;

[0136] Subtracting the power of the guiding energy recovery module from the braking power yields the power of the guiding braking resistor box.

[0137] The power of the guide braking resistor box is output as the final control command.

[0138] Example 2: This example provides an optimized method for monitoring and controlling regenerative braking in a braking resistor box; this example is based on the method described in Example 1, and combines... Figures 2 to 4 The algorithm's specific execution steps, parameter settings, and the physical meaning of the thermodynamic model are further explained in detail, including:

[0139] Reference Figure 2The step of calculating the temperature difference by subtracting the surface temperature of the braking resistor box from the ambient temperature includes:

[0140] The purpose of this step is to establish the basic thermodynamic relationship between the braking system and the external environment, providing a driving force for subsequent energy flow calculations.

[0141] At the start of this step, a high-frequency surface temperature sensor is first mounted on the central surface area of ​​the braking resistor box where heat dissipation is most concentrated. An ambient temperature sensor is then placed at the air inlet, away from heat radiation, and a communication link is established to acquire the surface temperature of the braking resistor box in real time. and ambient temperature ;

[0142] Subsequently, the temperature difference is calculated by subtracting the real-time surface temperature from the ambient temperature using the following formula:

[0143] in, Indicates the temperature difference value; Indicates the surface temperature of the braking resistor box; Indicates ambient temperature.

[0144] By acquiring the surface temperature of the braking resistor box and the ambient temperature, and subtracting the two to extract the temperature difference, a thermodynamic gradient benchmark between the entire energy recovery system and the external cooling medium was constructed. In actual industrial and vehicle operation scenarios, the ambient temperature of the equipment typically fluctuates significantly with seasonal changes, day-night cycles, and geographical location shifts. If the monitoring system relies solely on the absolute temperature of the braking resistor box surface to determine the overheating state and safety boundary of the equipment, it may easily overlook changes in the actual cooling potential of the external cold source. By directly acquiring the temperatures at two key locations and calculating the difference, the system can objectively reflect the temperature gradient between the equipment body and the surrounding environment at a specific moment. The mechanism assesses the true physical potential energy of the heat dissipated and accumulated in the surrounding environment. This thermodynamic state assessment mechanism based on dynamic temperature difference eliminates the limitations of a single absolute temperature benchmark under different climate and ventilation conditions. It provides a fundamental driving force input that conforms to the macroscopic laws of heat transfer for subsequent deduction of complex heat conduction networks and convective heat transfer intensity. This enables the monitoring algorithm system to have adaptive dynamic adjustment characteristics for variable external climate features. It avoids the risk of overestimating the heat capacity of equipment due to low absolute temperature in frigid environments, or prematurely triggering the system overheat protection action due to high initial temperature in hot environments. This improves the objectivity of the thermal state assessment of the braking system and the reliability of monitoring and early warning.

[0145] The step of multiplying the braking voltage and braking current to calculate the braking power, and then dividing the braking power by the surface area of ​​the braking resistor box to calculate the energy density, includes:

[0146] The principle of this step is to convert the electrical input at the bus end into the boundary conditions of the thermal system.

[0147] At the beginning of this step, a voltage sensor and a current sensor are first installed at the input bus of the braking resistor box to establish a sampling link to obtain the braking voltage in real time. and braking current ;

[0148] Subsequently, the braking power is calculated by multiplying the voltage and current using the following formula:

[0149] in, Indicates braking power; Indicates braking voltage; Indicates braking current;

[0150] Obtain the inherent surface area of ​​the braking resistor box of the equipment. ;

[0151] After obtaining the braking power, in order to normalize the physical dimensions of the equipment, the energy density is calculated using the pre-obtained structural parameters, and the energy density is calculated using the following formula:

[0152] in, Indicates energy density; Indicates braking power; This indicates the surface area of ​​the braking resistor box.

[0153] By synchronously acquiring braking voltage and braking current, multiplying them to obtain transient braking power, and then dividing it by the pre-acquired surface area of ​​the braking resistor box to obtain energy density, a quantitative index for the intensity of electromechanical energy conversion to thermal energy is established. During braking under frequent changing operating conditions, the voltage and current signals at the bus end exhibit high-frequency fluctuations and unsteady-state characteristics. Directly using this overall electrical power as an evaluation parameter for thermal shock makes it difficult to measure the actual thermal stress concentration per unit area of ​​material. Distributing the instantaneously generated total braking power across the effective heat dissipation surface area of ​​the equipment achieves spatial normalization of the electromagnetic energy injection intensity. This calculation method... This transforms abstract overall electrical parameters into specific physical parameters that characterize the intensity of localized heating of materials. This enables lateral comparison and unified monitoring of braking resistor boxes with different volume specifications or physical dimensions under the same energy density scale. It provides a spatially relevant reference for subsequent evaluation of the heat conduction hysteresis effect caused by high-frequency braking energy inside the equipment. It avoids power evaluation deviations caused by differences in equipment size. It helps to capture the physical trend of rapid heat accumulation in local areas in the early stage of braking, improves the system's sensitivity to nonlinear thermal shock states, and enhances its universal adaptability to different hardware structures.

[0154] The step of calculating the delay coefficient by exponentially decaying the basic delay time constant using energy density, and then converting it into a delay weight by combining the sampling interval, includes:

[0155] This step aims to address the lag distortion problem in energy assessment under high-frequency braking conditions;

[0156] Set the base delay time constant Its value is based on the inherent thermal inertia characteristics of the system under normal conditions. The larger the value, the more delayed the system's response to temperature changes. The smaller the value, the more susceptible it is to high-frequency physical noise interference.

[0157] Set reference energy density Its value is based on the continuous braking energy density under the rated power of the system. The larger the value, the lower the sensitivity of the system to power changes, and the smaller the value, the more severe the decay of the delay coefficient.

[0158] Subsequently, the fundamental delay time constant is corrected by negative exponential decay using the calculated energy density, and the delay factor is calculated using the following formula:

[0159] in, Indicates the delay factor; Represents the basic delay time constant; Indicates energy density; Indicates the reference energy density;

[0160] Set sampling time interval Its value is based on the sensor hardware sampling frequency limit and the Nyquist sampling theorem. A larger value may lead to the omission of high-frequency dynamic features, while a smaller value will increase the computing power burden of the underlying hardware.

[0161] After obtaining the delay coefficient, it needs to be mapped and fused with the sampling time to calculate the delay weight, which is calculated using the following formula:

[0162] in, Indicates the delay weight; Indicates the sampling time interval; This represents the delay coefficient.

[0163] By dividing the real-time calculated energy density by a preset reference energy density, taking the negative of the division result to perform a natural exponential operation, and then multiplying it by the basic delay time constant to obtain a delay coefficient, this coefficient is converted into a delay weight by combining it with the sampling time interval. This establishes a dynamic compensation mechanism for unsteady-state heat conduction processes. In the physical characteristics of heat conduction within solid materials, there is an inherent time lag in the transfer of heat from the internal heating core to the external surface sensor. Furthermore, this lag is not constant; when the externally injected braking energy density increases sharply, the thermodynamic gradient formed within the material becomes steeper, macroscopically accelerating the heat transfer response rate, manifesting as a significant physical phenomenon. The delay time is shortened; the mathematical form of a negative exponential function is used to attenuate and correct the basic delay time constant, objectively fitting the objective law of the nonlinear decrease of thermal conduction resistance under high energy input conditions; the abstract delay time constant is fused with the system's sampling time interval and converted into a dimensionless delay weight, so that the physical delay characteristics in the continuous time domain can be smoothly mapped to the discrete digital sampling control cycle; this processing action alleviates the problem of temperature signal measurement lag caused by sensor installation location; it ensures that the thermal state change information obtained in subsequent algorithms can correspond to the actual physical thermal shock events on the time axis, enhancing the synchronicity of transient monitoring data in the time domain.

[0164] The initial temperature change rate is calculated using the time difference of surface temperature, and noise suppression parameters are calculated by combining the delay coefficient and the temperature difference, including:

[0165] This step is used to suppress the interference of high-frequency electrical noise from the sensor on the calculation of the rate of temperature change;

[0166] The surface temperature of the braking resistor box at the previous moment is obtained by retrieving historical temperature data from the system memory of the previous sampling period. ;

[0167] Subsequently, the initial temperature change rate is calculated using the difference between the current temperature and the temperature at the previous moment, using the following formula:

[0168] in, Indicates the rate of change of initial temperature; Indicates the surface temperature of the braking resistor box; This indicates the surface temperature of the braking resistor box at the previous moment; Indicates the sampling time interval;

[0169] Set a small positive constant to prevent division by zero. Its value is determined based on the underlying numerical stability requirements of the control unit's floating-point arithmetic, and is fixed at 0.001.

[0170] After obtaining the initial temperature change rate, a dynamic gated multiplier is constructed using absolute value constraints, and the noise suppression parameter is calculated using the following formula:

[0171] in, Indicates noise suppression parameters; Indicates the rate of change of initial temperature; Indicates the delay factor; Indicates the temperature difference value; It represents a small positive constant that prevents division by zero.

[0172] The initial temperature change rate is obtained by extracting the temperature from the previous moment and performing finite difference calculations. This rate is then multiplied by a delay coefficient and divided by the temperature difference, which has a small positive constant. The noise suppression parameter is finally obtained by taking the absolute value and performing negative natural exponent calculations, thus constructing a dynamic filtering model with spatiotemporal adaptive adjustment capabilities. In industrial environments, analog signals collected by temperature sensors are easily affected by high-frequency interference from electromagnetic radiation from high-voltage buses. Traditional monitoring systems, when directly performing time-difference derivatives on temperature signals with small fluctuations, drastically amplify these electrical noises, causing violent oscillations in the calculated rate of change. The model incorporates a delay coefficient... The characteristic temperature change rate is proportional to the macroscopic temperature difference, constructing a phase space mapping constraint mechanism. When the detected minute temperature fluctuations are caused by high-frequency physical noise, this mathematical structure can output a very small gating value to suppress the fluctuations. When the equipment suffers actual braking thermal shock and generates a real temperature rise, the operation process releases the filtering constraints. This nonlinear numerical processing operation achieves the preservation of useful low-frequency physical trends and the suppression of high-frequency interference noise without introducing a long sliding window. It improves the smoothness quality of the original temperature derivative signal and reduces the probability of the system triggering malfunctions due to sudden changes in electrical noise.

[0173] Reference Figure 3 The step of multiplying the delay weight and noise suppression parameter by the initial temperature change rate to obtain the optimized temperature change rate, and then calculating the dynamic equivalent coefficient of convective heat transfer in combination with energy conservation, includes:

[0174] The purpose of this step is to infer the actual convective heat dissipation efficiency from the measured response, that is, to realize the inversion of the dynamic equivalent heat dissipation coefficient.

[0175] First, the delay weight and noise suppression parameter are applied together to the initial temperature change rate to calculate the optimized temperature change rate using the following formula:

[0176] in, This represents the optimized rate of temperature change. Indicates the rate of change of initial temperature; Indicates the delay weight; Indicates noise suppression parameters;

[0177] Obtain the specific heat capacity of the inherent braking resistor box of the equipment. and the quality of the braking resistor box ;

[0178] Next, based on the thermodynamic law of conservation of energy, after deducting the sensible heat absorbed by the equipment itself, the dynamic equivalent coefficient of convective heat transfer is calculated using the following formula:

[0179] in, This represents the dynamic equivalent coefficient of convective heat transfer; Indicates braking power; Indicates the specific heat capacity of the braking resistor box; Indicates the mass of the braking resistor box; This represents the optimized rate of temperature change. This represents the surface area of ​​the braking resistor box; Indicates the temperature difference value; It represents a small positive constant that prevents division by zero.

[0180] By sequentially multiplying the initial temperature change rate by the previously calculated delay weights and noise suppression parameters to obtain the optimized temperature change rate, and combining specific heat capacity, mass, braking power, and temperature difference, the dynamic equivalent coefficient of convective heat transfer is calculated according to the energy balance law, realizing the dynamic inversion of complex convective heat dissipation boundary conditions. In actual vehicle operation, the air velocity, wind direction, and operating state of the cooling fan outside the braking resistor box are constantly changing dynamically. Traditional thermodynamic models relying on a fixed heat dissipation coefficient cannot truly characterize this nonlinear convective heat dissipation process. Combining the noise-resistant and time-delay-compensated temperature change rate with the inherent heat capacity properties of the equipment enables… The system accurately quantifies the actual sensible heat absorption of the equipment's materials at the current moment. Then, by subtracting this heat absorption from the total braking input power, the remaining energy represents the heat dissipated to the external environment at the current moment. The resulting equivalent heat dissipation coefficient reduces the need for complex measurements of external fluid dynamics parameters, directly extracting macroscopic cooling efficiency indicators from the system's own electrothermal response. This inversion mechanism based on the law of energy conservation enables the system to adapt to random fluctuations in external cooling conditions in real time. It provides heat dissipation capacity parameters that fit actual physical conditions for the subsequent delineation of safe power boundaries, improving the equipment's state tracking capability in unsteady heat dissipation environments.

[0181] Reference Figure 4The step of calculating the transient heat absorption limit power using specific heat capacity, mass, temperature difference, and extreme emergency braking time window, and then superimposing it with the real-time convection heat dissipation limit power to calculate the safe load-bearing power, includes:

[0182] This step aims to proactively calculate the power dissipation limits of the device without exceeding the redline temperature.

[0183] Set maximum allowable temperature The value is determined by subtracting the preset safety margin from the thermal damage limit of the braking resistor material. The larger the value, the larger the physical load capacity of the system, but the higher the risk of hardware burnout. The smaller the value, the safer it is, but it will cause a waste of heat capacity.

[0184] Set the extreme emergency braking time window The value is based on the longest continuous extreme operating time that the system is expected to face. The larger the value, the more conservative the calculated short-time tolerable peak power; the smaller the value, the more aggressive the calculated short-time heat absorption limit.

[0185] Subsequently, the transient heat capacity absorption limit power is calculated using the equipment's heat capacity properties and temperature margin. The transient heat capacity absorption limit power is calculated using the following formula:

[0186] in, This represents the transient heat capacity's limiting power for heat absorption; Indicates the specific heat capacity of the braking resistor box; Indicates the mass of the braking resistor box; Indicates the maximum permissible temperature; Indicates the surface temperature of the braking resistor box; Indicates the time window for extreme emergency braking;

[0187] Subsequently, the real-time heat dissipation capacity and transient heat absorption capacity are superimposed to calculate the safe load-bearing power of the braking resistor box. The safe load-bearing power of the braking resistor box is calculated using the following formula:

[0188] in, Indicates the safe power carrying capacity of the braking resistor box; This represents the dynamic equivalent coefficient of convective heat transfer; This represents the surface area of ​​the braking resistor box; Indicates the maximum permissible temperature; Indicates the surface temperature of the braking resistor box; This represents the transient heat capacity absorption limit power.

[0189] The temperature margin difference is obtained by setting the maximum allowable temperature and the surface temperature of the braking resistor box. Combined with physical properties and the extreme emergency braking time window, the transient heat capacity absorption limit power is calculated, and this is added to the real-time convection heat dissipation limit power to obtain the final safe load-bearing power of the braking resistor box. This establishes a load-bearing boundary assessment model that decouples steady-state heat dissipation and transient heat storage. When facing sudden extreme continuous braking conditions, the braking resistor box not only relies on external cold air convection to remove heat, but its large physical mass and material specific heat capacity also play a role in thermal energy buffering. Assessing the system's safety boundary solely based on the current heat dissipation capacity will underestimate the short-term impact resistance potential of large-mass equipment. By using the limit braking time window as a constraint, the maximum heat that the equipment can absorb within the allowable temperature margin is reasonably converted from the energy dimension to the power dimension. This transient heat absorption extreme value, representing the material's thermal capacity buffering capacity, is then linearly superimposed with the previously obtained real-time convective heat dissipation extreme value. This combined calculation method recreates the physical process of heat absorption of macroscopic objects under severe thermal shock. As a result, the final safe load-bearing power index not only encompasses the current cooling state of the system but also taps into the latent heat absorption margin of the hardware. This avoids the waste of braking energy absorption capacity caused by overly conservative system settings and improves the rationality and physical objectivity of the energy recovery safety boundary prediction.

[0190] The process of calculating the excess power by subtracting the safe load power from the braking power, and then mapping it using a nonlinear smoothing function to obtain the recovery activation coefficient, includes:

[0191] This step is used to establish a smooth transition mechanism for transferring braking power to the regeneration module;

[0192] First, calculate the excess power of the current braking power relative to the safety boundary using the following formula:

[0193] in, Indicates excess power; Indicates braking power; Indicates the safe power carrying capacity of the braking resistor box;

[0194] Set the shape factor used to adjust the smoothness of the transition. The value is based on the maximum power ramp rate that the power grid or recycling module can withstand. The larger the value, the more violent the power switching action, which manifests as a hard cut-in state. The smaller the value, the smoother the switching, but it will lead to slow heat power discharge.

[0195] Set the reference power as a benchmark. Its value is based on the rated steady-state braking power of the system. The larger the value, the wider the power distribution mapping transition zone; the smaller the value, the more abruptly the recovery action is triggered after exceeding the limit.

[0196] Subsequently, the excess power is mapped to a recovery activation coefficient between 0 and 1 using a nonlinear function, and the recovery activation coefficient is calculated using the following formula:

[0197] in, Indicates the activation coefficient for recycling; Represents the shape factor; Indicates excess power; Indicates the reference power.

[0198] By subtracting the safe carrying capacity from the real-time braking power to obtain the excess power, and then dividing the excess power by a set reference power and combining it with a shape factor, a nonlinear smooth mapping relationship is constructed using natural exponential calculation. The final output is the recovery activation coefficient, thus constructing a flexible switching filtering buffer layer for braking energy exceeding the carrying capacity. In conventional energy management strategies, when the input power is detected to exceed the system safety limit, a relay-style hard cutoff or a step-style direct allocation logic is typically used. This operation causes a large amount of braking energy to change direction in a very short time, inducing voltage and current surges in the vehicle power grid or energy storage battery network. Introducing a smoothing function to perform a nonlinear exponential mapping on the excess power crossing the safety boundary results in a calculation allocation coefficient exhibiting a continuous and smooth transition mathematical characteristic within the zero-to-one range. By adjusting the mapping shape and reference benchmark, the sensitive area and conversion rate of power transfer can be flexibly configured. This mechanism eliminates the step-change points in energy transfer control commands, making the braking power allocation action smoother, mitigating the impact of transient high-power transfer on the insulation and lifespan of surrounding electrical hardware, and improving the electrical stability and control compliance of the braking energy recovery network under extreme over-limit conditions.

[0199] The process of calculating the recovery module's command power by multiplying the braking power by the recovery activation coefficient, and then using the remaining power after deducting this command value as the resistor box's command power output, includes:

[0200] The purpose of this step is to achieve the final optimized distribution of braking energy;

[0201] First, the power of the guiding energy recovery module is extracted from the total braking power using the recovery activation coefficient, and then the power of the guiding energy recovery module is calculated using the following formula:

[0202] in, This indicates the power of the guided energy recovery module, which is output as the final control command. Indicates braking power; Indicates the activation coefficient for recycling;

[0203] Finally, the remaining power consumption of the guide braking resistor box is calculated to complete the monitoring, optimization, and allocation of the entire process. The power of the guide braking resistor box is calculated using the following formula:

[0204] in, The power of the guide braking resistor box is represented as the final control command output; Indicates braking power; This indicates the power of the guided energy recovery module.

[0205] By multiplying the total braking power by the previously obtained continuous recovery activation coefficient, the control power of the guided energy recovery module is calculated separately. The remaining value after deducting the recovered part from the total braking power is used as the command power of the resistor box for synchronous output, thus completing the global conservation and coordinated allocation of energy multi-path redirection. When facing high-frequency changing compound braking scenarios, it is necessary to take into account both the thermodynamic safety bottom line of the underlying hardware and the energy recovery and utilization efficiency of the whole vehicle. Through this multiplicative allocation and addition-subtraction difference command issuance method, it is ensured that the mathematical sum of the two split power paths is strictly equal to the actual total braking power generated instantaneously at the front end. This calculation output step based on energy conservation logic avoids the situation of command superposition overflow or value loss in the power command allocation stage. It allows the excess heat energy that exceeds the dynamic bearing limit of the braking resistor box to be smoothly guided to the energy recovery module for secondary utilization. The remaining braking power within the safe range continues to be absorbed and dissipated by the resistor box. This allocation mechanism, while ensuring that the heat-generating components operate within the physical safety range, schedules the flow of excess braking energy, improving the integrity of energy management and the orderliness of resource allocation in the electromechanical system.

[0206] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0207] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for monitoring and optimizing the braking energy recovery of a braking resistor box, characterized in that, include: The temperature difference is calculated by subtracting the surface temperature of the braking resistor box from the ambient temperature. The braking power is calculated by multiplying the braking voltage and the braking current, and the energy density is calculated by dividing the braking power by the surface area of ​​the braking resistor box. The delay coefficient is calculated by exponentially decaying the basic delay time constant using energy density, and then converted into a delay weight by combining the sampling interval. The initial temperature change rate is calculated using the time difference of surface temperature, and the noise suppression parameters are calculated by combining the delay coefficient and the temperature difference. The optimal temperature change rate is obtained by multiplying the delay weight and noise suppression parameter into the initial temperature change rate, and the dynamic equivalent coefficient of convective heat transfer is calculated by combining energy conservation. The transient heat absorption limit power is calculated using specific heat capacity, mass, temperature difference, and extreme emergency braking time window, and then superimposed with the real-time convection heat dissipation limit power to calculate the safe load-bearing power. The excess power is calculated by subtracting the safe load power from the braking power, and the recovery activation coefficient is obtained by mapping through a nonlinear smoothing function. The command power of the recovery module is calculated by multiplying the braking power by the recovery activation coefficient, and the remaining power after deducting the command value is used as the command power output of the resistor box.

2. The method for monitoring and optimizing braking energy recovery in a braking resistor box according to claim 1, characterized in that, The step of calculating the temperature difference by subtracting the surface temperature of the braking resistor box from the ambient temperature includes: Obtain the surface temperature of the braking resistor box and the ambient temperature; The temperature difference is obtained by subtracting the ambient temperature from the obtained surface temperature of the braking resistor box.

3. The method for monitoring and optimizing braking energy recovery in a braking resistor box according to claim 2, characterized in that, The step of multiplying the braking voltage and braking current to calculate the braking power, and then dividing the braking power by the surface area of ​​the braking resistor box to calculate the energy density, includes: Obtain the braking voltage and braking current; The braking power is obtained by multiplying the obtained braking voltage by the braking current. Obtain the surface area of ​​the braking resistor box; The energy density is obtained by dividing the braking power by the surface area of ​​the braking resistor box.

4. The method for monitoring and optimizing braking energy recovery in a braking resistor box according to claim 3, characterized in that, The step of calculating the delay coefficient by exponentially decaying the basic delay time constant using energy density, and then converting it into a delay weight by combining the sampling interval, includes: Set the basic delay time constant and the reference energy density; Divide the energy density by the reference energy density, and take the negative value of the result of the division as the exponent for natural exponentiation. The delay coefficient is obtained by multiplying the result of the natural exponent calculation by the basic delay time constant. Set the sampling time interval; The delay weight is obtained by dividing the sampling time interval by the sum of the sampling time interval and the delay coefficient.

5. The method for monitoring and optimizing braking energy recovery in a braking resistor box according to claim 4, characterized in that, The initial temperature change rate is calculated using the time difference of surface temperature, and noise suppression parameters are calculated by combining the delay coefficient and the temperature difference, including: Obtain the surface temperature of the braking resistor box at the previous moment; Subtracting the previous moment's surface temperature from the surface temperature of the braking resistor box yields the temperature change difference. Divide the temperature change difference by the sampling time interval to obtain the initial temperature change rate; Set a small positive constant; Multiply the initial temperature change rate by the delay coefficient to obtain the product result; Add the temperature difference to the small positive constant to obtain the summation result; Divide the product by the sum and calculate the absolute value of the division. The absolute value is then negative and used as the exponent for natural exponentiation. The noise suppression parameter is obtained by subtracting the result of the natural exponent calculation from the numerical value.

6. The method for monitoring and optimizing braking energy recovery in a braking resistor box according to claim 5, characterized in that, The process of multiplying the delay weight and noise suppression parameter into the initial temperature change rate to obtain the optimized temperature change rate, and then calculating the dynamic equivalent coefficient of convective heat transfer in conjunction with energy conservation, includes: The optimized temperature change rate is obtained by multiplying the initial temperature change rate, the delay weight, and the noise suppression parameter. Obtain the specific heat capacity and mass of the braking resistor box; The heat absorption parameters are obtained by multiplying the specific heat capacity of the braking resistor box, the mass of the braking resistor box, and the optimized temperature change rate. Subtracting the heat absorption parameter from the braking power yields the convective heat transfer term; Multiply the surface area of ​​the braking resistor box by the temperature difference, and add the result of the multiplication to the small positive constant to obtain the denominator term of the convective heat transfer. Dividing the numerator of the convective heat transfer by the denominator of the convective heat transfer yields the dynamic equivalent coefficient of the convective heat transfer.

7. The method for monitoring and optimizing braking energy recovery in a braking resistor box according to claim 6, characterized in that, The calculation of the transient heat absorption limit power using specific heat capacity, mass, temperature difference, and extreme emergency braking time window, and the superposition of this power with the real-time convection heat dissipation limit power to calculate the safe load-bearing power, includes: Set the maximum permissible temperature and the extreme emergency braking time window; Subtracting the surface temperature of the braking resistor box from the maximum allowable temperature yields the temperature margin difference. The maximum heat absorption is obtained by multiplying the specific heat capacity of the braking resistor box, the mass of the braking resistor box, and the temperature margin difference. Divide the ultimate heat absorption by the ultimate emergency braking time window to obtain the transient heat capacity heat absorption ultimate power; Multiply the convective heat transfer dynamic equivalent coefficient, the surface area of ​​the braking resistor box, and the temperature margin difference to obtain the real-time convective heat dissipation limit power. The safe load-bearing power of the braking resistor box is obtained by adding the real-time convection heat dissipation limit power to the transient heat capacity heat absorption limit power.

8. The method for monitoring and optimizing braking energy recovery in a braking resistor box according to claim 7, characterized in that, The process of calculating the excess power by subtracting the safe load power from the braking power, and then mapping it using a nonlinear smoothing function to obtain the recovery activation coefficient, includes: The excess power is obtained by subtracting the safe bearing power of the braking resistor box from the braking power. Set the shape factor and reference power; Divide the excess power by the reference power, and multiply the result of the division by the shape factor; The negative value of the multiplication result is used as the exponent for natural exponentiation. Add the result of the natural exponent calculation to the numerical value to obtain the activated denominator term; Divide the value by the activation denominator to obtain the recycling activation coefficient.

9. The method for monitoring and optimizing braking energy recovery in a braking resistor box according to claim 8, characterized in that, The process of calculating the recovery module's command power by multiplying the braking power by the recovery activation coefficient, and then using the remaining power after deducting this command value as the resistor box's command power output, includes: Multiplying the braking power by the recovery activation coefficient yields the power of the guiding energy recovery module; The power of the guided energy recovery module is output as the final control command; Subtracting the power of the guiding energy recovery module from the braking power yields the power of the guiding braking resistor box. The power of the guide braking resistor box is output as the final control command.

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