A sodium-hydrogen composite power heavy truck multi-target energy distribution management method and system

Abstract

The application provides a sodium-hydrogen composite power heavy truck multi-target energy distribution management method and system, which comprises the following steps: acquiring vehicle operation data, fuel cell operation data, each battery module state data and front road data, predicting a power polarity switching time, a regenerative braking demand power and a power polarity isolation interval; selecting a seed battery module in the power polarity isolation interval, controlling the fuel cell to reduce net output power, compensating for the traction power gap by a sodium ion battery pack, and heating the seed battery module by using the residual electric power and waste heat of the fuel cell; when the regenerative braking opening condition is met, controlling the drive motor to establish regenerative braking and make the seed battery module receive the first section of regenerative energy. The application predicts the power polarity switching time and sets the power polarity isolation interval, so that the fuel cell reduces the net output power in advance, and the superposition of the residual charging power of the fuel cell and the regenerative power of the drive motor is avoided.

Description

Technical Field

[0001] This invention relates to the field of energy management technology for new energy heavy-duty vehicles, and in particular to a multi-objective energy distribution management method and system for sodium-hydrogen composite power heavy-duty trucks. Background Technology

[0002] Sodium-hydrogen hybrid heavy-duty trucks typically use a fuel cell and a sodium-ion battery pack for power. The fuel cell provides continuous power output, while the sodium-ion battery pack compensates for power shortages during acceleration and hill climbing, and receives regenerative energy from the drive motor during deceleration or downhill driving. Existing energy management methods primarily allocate fuel cell output power and sodium-ion battery pack charging / discharging power based on vehicle power demand, fuel cell operating status, and sodium-ion battery pack state of charge.

[0003] When a heavy-duty truck transitions from traction to downhill regenerative braking, the fuel cell, limited by gas and hydrogen supply, cooling, and power change rates, cannot immediately stop output as the drive motor enters regenerative braking. At this time, the remaining power of the fuel cell not consumed by the traction load and onboard accessories may simultaneously enter the high-voltage DC bus along with the regenerative power from the drive motor. If the combined power exceeds the available charging power of the sodium-ion battery pack, it can easily cause a rise in bus voltage, battery charging exceeding limits, or a forced reduction in regenerative braking power. Existing methods mostly limit regenerative power after power overlap occurs, making it difficult to coordinate the fuel cell power reduction process with the regenerative braking establishment process in advance.

[0004] At low temperatures, the usable charging power of sodium-ion battery modules decreases, and different battery modules have varying regenerative energy receiving capabilities due to differences in temperature, state of charge, state of health, internal resistance, and individual cell voltage margin. Existing methods of uniform current limiting or uniform preheating of the entire battery pack are usually limited by battery modules with weaker receiving capabilities. This not only results in high preheating energy consumption but may also prevent all battery modules from reaching an effective receiving state before the vehicle enters a downhill section, leading to a loss of recyclable energy and increased burden on auxiliary braking.

[0005] Therefore, this invention proposes a multi-objective energy distribution management method and system for sodium-hydrogen composite power heavy-duty trucks. The information disclosed in the background section is only for enhancing understanding of the background of this disclosure and may therefore contain prior art information that is not common knowledge to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a multi-objective energy distribution management method and system for sodium-hydrogen composite power heavy trucks, thereby solving the technical problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A multi-objective energy distribution management method for sodium-hydrogen composite power heavy-duty trucks includes the following steps: S1. Obtain vehicle speed, traction system power demand, road gradient sequence, fuel cell net output power, battery module temperature, available charging power and single cell voltage margin, and predict power polarity switching time, regenerative braking power demand and power polarity isolation range. S2. Select the seed battery module within the power polarity isolation range, control the fuel cell to reduce the net output power, use the sodium-ion battery pack to compensate for the traction power gap, and use the remaining power and waste heat of the fuel cell to heat the seed battery module so that it reaches the first stage of regenerative energy receiving conditions. S3. Determine the regenerative braking opening conditions based on the remaining charging power of the fuel cell, the available charging power of the seed battery module, the remaining rechargeable energy, and the single cell voltage margin. Control the drive motor to establish regenerative braking and distribute the first stage of regenerative energy to the seed battery module. S4. Determine the battery modules to be activated and their activation order based on the activation heating energy, expected activation time and effective receiving capability of the unactivated battery modules, allocate the propagation heating power from the regeneration power to the battery modules to be activated, and add them to the set of activated battery modules when they reach the receiving conditions. S5. Based on the total effective receiving capacity of the activated battery module set, the remaining expected regenerative energy, and the vehicle braking demand, adjust the target net output power of the fuel cell, the target regenerative power of the drive motor, the target charging current of each activated battery module, the target power of propagation heating, and the target power of auxiliary braking until the regenerative braking process is completed.

[0008] A multi-objective energy distribution management system for sodium-hydrogen composite power heavy-duty trucks includes: Fuel cells, sodium-ion battery packs, drive motors, auxiliary braking devices, a whole-pack bidirectional DC-DC converter, a vehicle controller, and module-level bidirectional converter units, battery module heating circuits, and controllable heat exchange circuits corresponding to each battery module. The vehicle controller includes: The information acquisition and prediction module is used to acquire vehicle operation data, fuel cell operation data, status data of each battery module and road ahead data, and predict the power polarity switching time, regenerative braking power demand and power polarity isolation range. The isolation activation module is used to screen and select seed battery modules, control the fuel cell to reduce net output power, compensate for the traction power gap by sodium-ion battery pack, and use the remaining electric power and waste heat of fuel cell to heat seed battery modules. The first-stage regeneration control module is used to determine the regeneration braking opening conditions based on the remaining charging power of the fuel cell, the available charging power of the seed battery module, the remaining rechargeable energy, and the single-cell voltage margin, and to control the drive motor to establish regeneration braking and enable the seed battery module to receive the first-stage regeneration energy. The module propagation module is used to determine the battery modules to be activated and the module activation order, allocate propagation heating power from the regenerative power of the drive motor, and add the battery modules to be activated that meet the receiving conditions to the set of activated battery modules. The collaborative allocation module is used to adjust the target net output power of the fuel cell, the target regenerative power of the drive motor, the target charging current of each activated battery module, the target power of propagation heating, and the target power of auxiliary braking based on the total effective receiving capacity of the activated battery module set, the remaining expected regenerative energy, and the vehicle braking demand.

[0009] The beneficial effects of this invention are as follows: This invention predicts the power polarity switching moment and sets a power polarity isolation interval, enabling the fuel cell to reduce its net output power in advance and avoid exceeding the limit by combining the remaining charging power of the fuel cell with the regenerative power of the drive motor. By selecting a seed battery module and using the remaining electrical power and waste heat of the fuel cell for targeted heating, the initial regenerative energy receiving capability can be quickly established before the entire pack is fully preheated.

[0010] This invention reduces the risks of low-temperature charging, individual cell voltage exceeding limits, and high-voltage DC bus voltage fluctuations by controlling the regenerative braking opening based on the available charging power, remaining rechargeable energy, and individual cell voltage margin of the battery module. By using a portion of the regenerative power for propagating heating of the battery modules to be activated, more battery modules are sequentially added to the activated battery module set, reducing energy consumption caused by uniform preheating of the entire pack.

[0011] This invention allocates target charging current according to the effective receiving capacity of each activated battery module, avoiding the limitation of the entire pack's regenerative receiving capacity by battery modules with weaker receiving capabilities, thereby improving the utilization rate of regenerative energy. By coordinating the target power of the fuel cell, drive motor, battery module heating circuit, and auxiliary braking device, the total braking force of the vehicle remains stable when the receiving capacity of the battery modules changes, balancing braking safety and energy recovery efficiency. Attached Figure Description

[0012] Figure 1 This is a flowchart of the multi-target energy distribution management method for sodium-hydrogen composite power heavy trucks of the present invention; Figure 2 This is a framework diagram of the sodium-hydrogen composite power heavy truck multi-target energy distribution management system of the present invention; Figure 3 This is a high-voltage electrical and control topology diagram of the composite power system of the present invention; Figure 4 This is a topology diagram of the waste heat management of the fuel cell and the thermal management of the sodium-ion battery module in this invention. Detailed Implementation

[0013] 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.

[0014] Example 1: As Figure 1 As shown, this embodiment provides a multi-objective energy distribution management method for sodium-hydrogen hybrid power heavy-duty trucks, specifically a multi-objective energy distribution management method for fuel cell-sodium-ion battery hybrid power heavy-duty tractor vehicles, including the following steps: S1. Obtain vehicle speed, traction system power demand, road gradient sequence, fuel cell net output power, battery module temperature, available charging power and single cell voltage margin, and predict power polarity switching time, regenerative braking power demand and power polarity isolation range. S2. Select the seed battery module within the power polarity isolation range, control the fuel cell to reduce the net output power, use the sodium-ion battery pack to compensate for the traction power gap, and use the remaining power and waste heat of the fuel cell to heat the seed battery module so that it reaches the first stage of regenerative energy receiving conditions. S3. Determine the regenerative braking opening conditions based on the remaining charging power of the fuel cell, the available charging power of the seed battery module, the remaining rechargeable energy, and the single cell voltage margin. Control the drive motor to establish regenerative braking and distribute the first stage of regenerative energy to the seed battery module. S4. Determine the battery modules to be activated and their activation order based on the activation heating energy, expected activation time and effective receiving capability of the unactivated battery modules, allocate the propagation heating power from the regeneration power to the battery modules to be activated, and add them to the set of activated battery modules when they reach the receiving conditions. S5. Based on the total effective receiving capacity of the activated battery module set, the remaining expected regenerative energy, and the vehicle braking demand, adjust the target net output power of the fuel cell, the target regenerative power of the drive motor, the target charging current of each activated battery module, the target power of propagation heating, and the target power of auxiliary braking until the regenerative braking process is completed.

[0015] The electric vehicle power unit of this embodiment includes a fuel cell, a sodium-ion battery pack, a pack-level bidirectional DC-DC converter, multiple module-level bidirectional converter units, a drive motor, an auxiliary braking device, and a vehicle controller. The sodium-ion battery pack includes multiple battery modules, each of which is equipped with a battery module heating branch and a controllable heat exchange branch; the whole pack-level bidirectional DC-DC converter is used for the whole pack power exchange, and the module-level bidirectional conversion unit is used for the charging, discharging and heating power distribution of the corresponding battery module.

[0016] Hereinafter, i represents the battery module number, j represents the road prediction location number, k represents the control cycle number, and n represents the current control cycle number corresponding to the cumulative calculation.

[0017] S1 specifically includes the following sub-steps: S110. Acquire real-time operating data of the electric vehicle's power unit and road data ahead to form a basic operating dataset. Real-time operating data includes vehicle load, real-time vehicle speed, actual torque and speed of the drive motor, actual net output power of the fuel cell and allowable power reduction rate, actual power consumption of on-board accessories, and the state of charge, state of health, minimum temperature, maximum temperature, internal resistance, available charging power, and single-cell voltage margin of each battery module.

[0018] The vehicle load is obtained by summing the detection values ​​of the front axle load sensor and the rear axle load sensor; the real-time vehicle speed is determined by the vehicle controller after reading the data from each wheel speed sensor and eliminating abnormal wheel speeds corresponding to slipping wheels and faulty wheels; the drive motor data is provided by the drive motor controller; the actual net output power of the fuel cell is obtained by subtracting the actual power of the air compressor, hydrogen circulation device and coolant pump from the product of the output voltage and the output current; the allowable power reduction rate of the fuel cell is obtained by the fuel cell controller from the calibration spectrum based on the stack temperature, air flow, single-cell voltage dispersion and the current power change status; the actual power consumption of on-board accessories is obtained by the accessory controller.

[0019] The state of charge (SOC), state of health (SOC), internal resistance, and available charging power for each battery module are provided by the battery management system (BMS). The minimum and maximum temperatures are taken as the minimum and maximum values ​​among all temperature readings for that battery module, respectively. The individual cell voltage margin is the difference between the upper limit of the allowable charging voltage and the current highest individual cell voltage. The available charging power is the current maximum allowable charging power determined by the BMS based on a comprehensive analysis of individual cell voltage, temperature, SOC, SOC, and allowable charging current.

[0020] The road data ahead is obtained by combining road mileage points and elevation points from the in-vehicle navigation map with the vehicle's current location output by the Global Navigation Satellite System. Road segments within a preset predicted distance are extracted along the driving direction to form a road gradient sequence containing segment length, road gradient, and speed limit values. The vehicle controller performs time alignment with a control cycle of 100ms; continuously changing data is interpolated linearly, and the switch state is held by the most recent time. Data that has not been updated for more than 500ms is marked as invalid. When critical data is continuously invalid, the generation of new prediction results is stopped and safety degradation control is executed.

[0021] It should be noted that the various "calibration charts" (such as fuel cell allowable power degradation rate calibration chart, charging power calibration chart, charging efficiency calibration chart, etc.) mentioned in the embodiments of the present invention are all three-dimensional data lookup tables (MAP charts) generated by testing and fitting under various operating conditions such as different ambient temperatures, state of charge, and power requirements before the vehicle or core components leave the factory through standard bench tests in the field (such as battery high and low temperature charge and discharge bench tests, fuel cell bench calibration tests), and pre-fixed and stored in the non-volatile memory of the corresponding controller for real-time calling by the program.

[0022] The time-aligned real-time running data and road slope sequence are combined to form the basic running dataset, which is then input into S120.

[0023] S120. Based on the basic operation dataset, predict the traction system power demand and regenerative braking power demand at each predicted road location. The traction system power demand is calculated using the following formula:

[0024] In the formula, The traction system power requirement is given by kW for the j-th predicted road location; m is the total vehicle mass, in kg. The longitudinal acceleration of the target is expressed in m / s². 2 g is the acceleration due to gravity, with units of m / s². 2 ; The road slope angle; This is the rolling resistance coefficient; Air density, unit: kg / m³ 3 ; A is the air resistance coefficient; A is the frontal area, in m². 2 ; To predict vehicle speed, the unit is m / s; For transmission efficiency; The coefficient for converting W to kW.

[0025] Vehicle parameters are read from the vehicle parameter table, air density is determined by ambient temperature and atmospheric pressure, and transmission efficiency is obtained from the calibration charts corresponding to motor speed, torque, and gear position. When this is the case, it is determined as the predicted traction power; When the absolute value is determined, it is taken as the predicted regenerative braking power. The predicted power of on-board accessories is given separately by the accessory controller and is not included in the power demand of the traction system. The target longitudinal acceleration is obtained by dividing the difference between the target vehicle speed and the predicted vehicle speed by the prediction time interval, and is corrected according to the brake pedal opening and braking deceleration calibration chart.

[0026] When the traction system's power demand is not greater than the first power threshold for the first time, and the power demand is not greater than the second power threshold for the next three consecutive road prediction positions, the corresponding prediction time is determined as the power polarity switching time. The first power threshold is a positive value close to 0 (e.g., set in the range of 0 to 5kW), and the second power threshold is a negative value reflecting the actual regenerative braking state (e.g., set in the range of -10kW to -20kW). The specific values ​​of the two are determined by the road power prediction error and the drive motor control error during the vehicle calibration stage.

[0027] The residual power of a fuel cell is predicted using the following formula:

[0028] In the formula, For the predicted time The residual power of the fuel cell, in kW; This represents the current actual net output power of the fuel cell, expressed in kW. The allowable power decay rate of the fuel cell, in kW / s; The current time is expressed in seconds (s). This represents the minimum net output power of a fuel cell, expressed in kW.

[0029] The polarity switching time, predicted traction power, predicted regenerative braking power, predicted power of on-board accessories, residual power of fuel cell, and corresponding road location are combined to form the polarity switching prediction result, which is then input into S130.

[0030] S130. Determine the power overlap period, power polarity isolation interval, and first-stage regenerative control parameters based on the polarity switching prediction results. The power overlap period is a continuous time period in which the drive motor has generated regenerative braking power, the fuel cell is still outputting positive power, and the combined power of both potentially entering the sodium-ion battery pack exceeds the allowable received power, determined according to the following formula:

[0031] In the formula, To predict regenerative braking power, Predict the total available charging power for sodium-ion battery packs. All values ​​are in kW to provide a safety margin for charging power.

[0032] The predicted total available charging power is obtained from the charging power calibration chart based on the current state of each battery module and the predicted temperature change; if a reliable prediction is not possible, the current total available charging power is used as a conservative value. The charging power safety margin is calibrated based on the prediction error, the response error of the module-level bidirectional converter unit, and the communication delay.

[0033] Based on the time required for the fuel cell to decrease to the allowable residual power threshold, the starting time of the power polarity isolation interval is calculated backward from the start of the power overlap period. The end time is determined when the sum of the residual power and the predicted regenerative braking power does not exceed the predicted total available charging power minus the safety margin for three consecutive control cycles. If the calculated start time is earlier than the current time, isolation control is initiated immediately.

[0034] The period from the moment regenerative braking is activated, with a preset initial duration, is defined as the first regeneration period. The preset initial duration is determined by bench testing based on the time required for a typical cryogenic module to establish its initial receiving capability. The initial regeneration power requirement is determined based on the predicted regenerative braking power during this period. After deducting the expected losses of the module-level bidirectional converter unit and adding the power prediction safety margin, the initial receiving power threshold is determined. The initial regeneration energy requirement is obtained by integrating the predicted regenerative braking power over time.

[0035] The isolation control baseline is composed of the power polarity isolation range, fuel cell power reduction benchmark, sodium-ion battery pack traction compensation requirement, first-stage regeneration power requirement, first-stage receiving power threshold, first-stage regeneration energy requirement, status data of each battery module, and the prohibition of opening regeneration braking flag, and is input into S210 and S220; when all battery modules cannot meet the first-stage regeneration control parameters, the prohibition of opening regeneration braking flag is set to valid.

[0036] S2 specifically includes the following sub-steps: S210: Read the isolation control reference, screen candidate battery modules, and determine the seed battery module. When the "prohibit regenerative braking" flag is valid, no candidate battery module screening is performed, and the seed module cannot be established. Then, proceed to S230 to generate the seed module activation failure state. When the flag is invalid, first exclude battery modules that have reached the upper limit of the allowable state of charge, have a single cell voltage margin lower than the minimum voltage margin, have insulation faults, have temperature sampling faults, have single cell voltage sampling faults, have module-level bidirectional conversion unit faults, or have battery module heating branch faults.

[0037] For the i-th battery module retained after exclusion, calculate the remaining rechargeable energy based on the rated energy, state of health, and state of charge provided by the battery management system, and the charging efficiency obtained from the charging efficiency calibration chart corresponding to the current lowest temperature and expected charging rate:

[0038] In the formula, This represents the remaining rechargeable energy of the i-th battery module, in kWh. This represents the rated energy of the i-th battery module, in kWh. This represents the health status of the i-th battery module. This represents the upper limit of the allowed state of charge during charging; This represents the current state of charge of the i-th battery module. Let be the charging efficiency of the i-th battery module.

[0039] Then, based on the calibration graph of the minimum temperature, state of charge, state of health and available charging power, find the minimum temperature at which the available charging power of the battery module reaches the first segment receiving power threshold. The sum of the minimum temperature and the temperature control margin is determined as the target temperature, and the target temperature must not exceed the upper limit of the allowable charging temperature.

[0040] Calculate the activation heating energy based on the target temperature:

[0041] In the formula, To activate the heating energy, the unit is kWh; Equivalent heat capacity calibrated by thermal testing, in kWh / ℃; The target temperature is expressed in °C. This is the current lowest temperature, in °C. The estimated heat dissipation is determined based on ambient temperature, driving wind speed, and battery pack insulation parameters, and is expressed in kWh. The overall efficiency of the heating branch of the battery module.

[0042] Battery modules with remaining rechargeable energy not less than the initial regeneration energy requirement, whose activation heating energy can be supplied within the power polarity isolation range, and whose usable charging power after heating reaches the initial receiving power threshold are identified as candidate battery modules. The module with the lowest activation heating energy is selected as the seed battery module; when activation heating energy is the same, the modules with larger single-cell voltage margin and smaller internal resistance are selected in sequence.

[0043] For example, if battery module A has an activation heating energy of 1.5 kWh and a remaining rechargeable energy of 0.8 kWh, and battery module B has an activation heating energy of 2 kWh and a remaining rechargeable energy of 4 kWh, and the initial regenerative energy requirement is 2.5 kWh, then battery module A should be excluded and battery module B should be selected.

[0044] Candidate battery modules are those that simultaneously meet the conditions of safety boundaries, remaining rechargeable energy, and heatable activation. Seed battery modules are candidate battery modules that first establish regenerative energy receiving capabilities and serve as the starting point for subsequent module propagation. If the set of candidate battery modules is empty, the seed module's inability to be established is written into the seed module control parameters, and no further heating commands are generated for individual battery modules.

[0045] The temperature control margin, minimum voltage margin, and power prediction safety margin used for the target temperature are all derived from the sodium-ion battery low-temperature charging bench test and are stored separately in the calibration parameter table of the vehicle controller. During operation, the same parameter must not be used to substitute for each other.

[0046] The seed battery module identification, target temperature, first segment receiving power threshold, activation heating energy, and remaining rechargeable energy constitute the seed module control parameters, which are then input into S220 and S230.

[0047] S220. Based on the isolation control baseline and seed module control parameters, generate a power transition scheme covering the power polarity isolation range. The power transition scheme records the timing control data of the fuel cell target net output power, sodium-ion battery pack traction compensation target power, seed battery module electric heating target power, fuel cell waste heat transfer target power, and on-board accessory predicted power using a 100ms control cycle as the index.

[0048] The target net output power of the fuel cell is determined based on the fuel cell power reduction benchmark and is limited by the allowable power reduction rate, minimum net output power, stack temperature, and single cell voltage dispersion. The target power of the sodium-ion battery pack traction compensation is limited by the available power of the entire pack discharge, minimum state of charge, and minimum single cell voltage. The target power of the seed battery module electric heating is determined based on the activation heating energy and remaining isolation time and is limited by the rated power of the battery module heating branch and the allowable output power of the module-level bidirectional converter heating direction.

[0049] The electrical power in each control cycle satisfies:

[0050] In the formula, To predict traction power, The target power for electric heating of the seed battery module, Predicting power for vehicle accessories, For the target net output power of the fuel cell, The target power for traction compensation of sodium-ion battery packs is given, and the unit is kW.

[0051] The target power for waste heat transfer from the fuel cell is determined based on the coolant inlet temperature, outlet temperature, flow rate, and heat exchange efficiency, and is not included in the aforementioned power balance. If the fuel cell cannot simultaneously meet the demands of traction, accessories, and heating, the sodium-ion battery pack will prioritize compensating for the traction power shortfall; only when the state of charge and minimum single-cell voltage of the sodium-ion battery pack are both higher than the corresponding discharge lower limit can it supplement power to the heating branch of the battery module.

[0052] When the deviation of the actual traction power, the actual net output power of the fuel cell, or the minimum temperature of the seed battery module from the planned value exceeds the calibrated allowable value, the power transition scheme for the subsequent control cycle is updated based on the remaining isolation time and input into S230.

[0053] S230. Power isolation and seed battery module activation are performed according to the power transition scheme. The vehicle controller sends target values ​​to the fuel cell controller, the whole pack-level bidirectional DC-DC converter, the module-level bidirectional converter unit corresponding to the seed battery module, and the thermal management controller, respectively. The thermal management controller adjusts the opening of the three-way proportional valve and the speed of the coolant pump in the controllable heat exchange branch, so that the high-temperature coolant carrying the waste heat of the fuel cell flows through the water-to-water heat exchanger. In the water-to-water heat exchanger, it performs heat exchange with the low-temperature coolant in the thermal management water circuit where the corresponding battery module is located, thereby safely transferring the waste heat of the fuel cell to the seed battery module.

[0054] Every 100ms, the seed battery module's minimum temperature, maximum temperature, available charging power, remaining rechargeable energy, maximum single-cell voltage, and fault status are read.

[0055] When the minimum temperature is not lower than the target temperature, the available charging power is not lower than the first segment receiving power threshold, the remaining rechargeable energy is not lower than the first segment regeneration energy requirement, the single-unit voltage margin is not lower than the minimum voltage margin, the maximum temperature does not exceed the upper limit of the allowable charging temperature and there is no fault, and the above conditions are met for 3 consecutive control cycles, the seed module activation status is set to activated.

[0056] Activation is not considered complete if the target temperature is reached but the individual cell voltage margin is insufficient. For example, if the individual cell voltage margin is 5mV and the minimum voltage margin is 20mV, regenerative braking should remain off. If the activation conditions are not met after the power polarity switching time, or if there is a temperature exceeding the limit, insufficient remaining rechargeable energy, or hardware failure, the activation process will be terminated and the seed module will fail to activate.

[0057] The seed battery module identifier, seed module activation status, actual net output power of fuel cell, seed battery module minimum temperature, maximum temperature, available charging power, remaining rechargeable energy, single cell voltage margin, remaining first-stage regenerative energy requirement, and failure reason are combined to form the isolated execution result and input into S310.

[0058] S3 specifically includes the following sub-steps: S310: Read the isolation execution result, determine the regenerative braking opening condition, and generate the first segment of regenerative power rise trajectory. When the seed module activation status is activation failure, keep the drive motor regenerative braking closed; if the failure is due to a fault in the seed battery module itself and there are still other candidate battery modules, return to S210 to reselect the seed battery module. If none of the battery modules have the first segment receiving capability, the auxiliary braking device will handle the vehicle braking requirements.

[0059] When the seed module is activated, the actual net output power of the fuel cell is read from the fuel cell controller, the actual power consumed by the on-board accessories is read from the accessory controller, and the actual power consumed by the heating branch of the battery module is read from the module-level bidirectional converter unit corresponding to the seed battery module. The drive motor controller calculates the actual power still used for vehicle traction based on the actual torque and speed, and calculates the remaining charging power of the fuel cell according to the following formula:

[0060] In the formula, The remaining charging power of the fuel cell in the k-th control cycle is expressed in kW. This represents the actual net output power of the fuel cell, in kW. The actual power consumption of vehicle accessories is expressed in kW. The actual power of the seed battery module's electric heating is expressed in kW. This represents the actual traction power, measured in kW.

[0061] The remaining charging power of the fuel cell represents the positive power that can still enter the seed battery module after deducting the current actual load. Then, the vehicle's braking power demand is read from the brake controller, the upper limit of power generation is read from the drive motor controller, the allowed input power for charging direction is read from the module-level bidirectional converter, and the available charging power, remaining rechargeable energy, and single-cell voltage margin of the seed battery module are read from the battery management system to determine the upper limit of the first stage of regenerative power.

[0062] In the formula, This is the upper limit of the first stage of regeneration power. For the vehicle's braking power requirements, This is the upper limit of the generator power of the drive motor. The allowable input power for the charging direction of the module-level bidirectional converter unit corresponding to the seed battery module. Available power for charging the seed battery module, all in kW.

[0063] When the seed module is activated, the target torque of the drive motor is less than 0, the remaining rechargeable energy is not less than the remaining first-stage regenerative energy requirement, the individual unit voltage margin is not less than the minimum voltage margin, the high-voltage DC bus voltage is within the allowable range, and the upper limit of the first-stage regenerative power is greater than 0, the regenerative braking opening conditions are confirmed to be met.

[0064] Based on the minimum value among the allowable torque change rate of the drive motor, the allowable current change rate of the module-level bidirectional conversion unit, the allowable charging current change rate of the seed battery module, and the braking smoothness calibration rate, the regenerative power is increased cycle by cycle to the upper limit of the first stage regenerative power, forming the first stage regenerative power rise trajectory and inputting it into S320.

[0065] S320: Control the first stage of regenerative energy reception according to the rising trajectory of the first stage of regenerative power. The vehicle controller converts the regenerative power target into a negative torque command for the drive motor, sends the target charging power of the seed battery module to the corresponding module-level bidirectional converter, and sends the difference between the total braking power demand of the vehicle and the actual regenerative power of the drive motor to the brake controller, which is then supplemented by the auxiliary braking device. When the regenerative power of the drive motor increases, the auxiliary braking power decreases by the same power increment to keep the total braking demand of the vehicle constant.

[0066] For example, if the total braking power requirement of a vehicle is 120kW, and the regenerative braking power is increased from 20kW to 35kW, the auxiliary braking power should be reduced from 100kW to 85kW.

[0067] Every 100ms, the terminal voltage and charging current of the seed battery module are collected from the module-level bidirectional conversion unit. The highest single-cell voltage, lowest temperature, highest temperature, available charging power, remaining rechargeable energy, and fault status are collected from the battery management system. The actual regenerative energy received by the seed battery module is accumulated according to the following formula:

[0068] In the formula, To enable control cycle from regenerative braking The received regenerated energy up to the current control cycle n, in kWh; This is the terminal voltage of the seed battery module, in volts (V). The charging current for the seed battery module, in amperes (A). The control period is measured in seconds (s). The coefficient for converting J to kWh.

[0069] When the highest single-cell voltage reaches the upper limit of the allowable charging voltage, the highest temperature reaches the upper limit of the allowable charging temperature, the actual charging power exceeds the available charging power, the high-voltage DC bus voltage exceeds the limit, or the controller malfunctions, regenerative braking will be immediately reduced or stopped, and the auxiliary braking device will make up for the vehicle's braking demand and generate a regenerative braking interruption status flag.

[0070] The seed battery module identifier, opening time, target regenerative power, actual regenerative power, actual received power, received regenerative energy, available charging power, remaining rechargeable energy, single cell voltage margin, minimum temperature, maximum temperature, remaining first-stage regenerative energy requirement, actual auxiliary braking power, and regenerative braking interruption status are combined to form the first-stage regenerative reception result, and input into S330.

[0071] S330. Generate propagation trigger data based on the first stage regeneration reception result. Update the first stage duration based on the first stage regeneration braking opening time, actual regeneration power, and regeneration braking interruption status; record the braking energy that has not been recovered before the current position based on the actual auxiliary braking power, but do not deduct this part of the energy again when predicting the remaining regeneration energy.

[0072] The regenerative power that can continue to be received is the maximum regenerative power that the seed battery module is allowed to receive in the next control cycle. It is the minimum value among the regenerative braking power requirement, the upper limit of the drive motor power generation, the allowed input power of the module-level bidirectional converter in the charging direction, and the seed battery module's available charging power minus the fuel cell's remaining charging power and charging power safety margin.

[0073] Based on the current location provided by the Global Navigation Satellite System, the real-time vehicle speed provided by wheel speed sensors, the remaining road gradient sequence provided by the onboard navigation map, and the vehicle braking demand provided by the brake controller, the remaining estimated regenerative energy after the current location is recalculated. The minimum traction reserve energy is calculated by the vehicle controller based on the predicted traction segment after regenerative braking ends, vehicle load, road gradient, fuel cell allowable power rise rate, and power recovery time.

[0074] The non-negative value of the regenerated energy received by the seed battery module after deducting the minimum traction reserve energy, module-level bidirectional conversion loss, expected heating branch loss, and control margin is determined as the propagation heating energy; the propagation heating energy is only used as the upper limit of the energy that can be allocated to the heating of subsequent battery modules, and the actual energy supply path is determined by S420.

[0075] A module expansion trigger signal is generated when the regenerative power that can be received is less than the power required for subsequent regenerative braking for three consecutive control cycles, the remaining rechargeable energy of the seed battery module is less than the remaining expected regenerative energy allocated to it, the highest single cell voltage will reach the allowable upper limit within a preset time at the current rate of increase, or the available charging power continuously drops below the first segment receiving power threshold.

[0076] For example, if the seed battery module can continue to receive 60kW and the subsequent regenerative braking power requirement is 50kW, but the remaining rechargeable energy is only 0.6kWh and the remaining expected regenerative energy is 3kWh, the module extension trigger signal should still be generated.

[0077] The propagation trigger data is composed of the module extension trigger signal, trigger reason, received regenerative energy, regenerative power that can be received, remaining rechargeable energy, propagation heating energy, remaining expected regenerative energy, minimum temperature, maximum temperature, single cell voltage margin, current regenerative braking power demand, regenerative braking interruption status, and unactivated battery module identifier, and is input into S410.

[0078] S4 specifically includes the following sub-steps: S410: Read the propagation trigger data and determine the activatable battery modules and their activation order based on the module expansion trigger signal. When the regenerative braking interruption state is valid, stop the propagation of new modules; when the module expansion trigger signal is invalid, maintain the set of activated battery modules from the previous control cycle. When entering the module propagation process for the first time, this set only includes the seed battery module.

[0079] An inactive battery module is a battery module that has not been added to the set of activated battery modules and does not have any faults in insulation, sampling, module-level bidirectional conversion unit, or battery module heating branch. An activatable battery module is an inactive battery module that can complete heating using propagated heating energy during the remaining regenerative braking time and has effective receiving capability after activation.

[0080] When the module expansion trigger signal is valid, the system reads the state of charge, state of health, minimum temperature, maximum temperature, internal resistance, available charging power, remaining rechargeable energy, and single-cell voltage margin of each unactivated battery module from the battery management system. The system updates the target temperature and activation heating energy according to the same calibration chart and calculation method as S210, and determines the receiving power threshold based on the expected regenerative power allocation after activation. The system calculates the remaining regenerative braking time based on the current position, real-time vehicle speed, and remaining road gradient sequence output by the global navigation satellite system.

[0081] The expected activation time is determined according to the following formula:

[0082] In the formula, The estimated activation time for the i-th unactivated battery module is in hours. To activate the heating energy, the unit is kWh; The effective heating power, measured in kW, is the minimum of the rated power of the battery module heating branch, the allowable output power of the module-level bidirectional converter in the heating direction, and the currently allocable regenerative power. The remaining regenerative braking time is uniformly converted to hours and compared with the expected activation time.

[0083] Based on the remaining expected regenerative energy, the expected effective receiving capacity after activation, and the total effective receiving capacity of the activated battery module set, the expected regenerative energy allocation after activation is determined according to the proportion of effective receiving capacity. Battery modules with activation heating energy not exceeding propagation heating energy, expected activation time not exceeding the remaining regenerative braking time, remaining rechargeable energy not less than the expected regenerative energy allocation after activation, and individual cell voltage margins meeting the requirements are identified as activatable battery modules.

[0084] Next, calculate the net revenue from the dissemination:

[0085] In the formula, The net propagation benefit of the i-th activatable battery module is expressed in kWh. This refers to the increase in available charging power relative to the current state after the battery module reaches the target temperature, expressed in kW. The remaining time from the completion of activation to the end of regenerative braking is estimated, in hours. To activate the heating energy.

[0086] The module activation order is determined by ranking the net propagation benefit from highest to lowest. When the net propagation benefit is the same, the modules with the shorter expected activation time, larger single-cell voltage margin, and lower internal resistance are selected in that order. The module ranked first is selected as the current battery module to be activated, and its activation heating energy is summed with the heating control margin determined by the low-temperature heating test to determine the heating energy quota.

[0087] For example, if battery module A requires 0.5 kWh of activation heating energy but has an expected activation time of 0.2 h, and battery module B requires 0.8 kWh of activation heating energy and has an expected activation time of 0.05 h, while the remaining regenerative braking time is 0.067 h, then battery module A should be excluded and battery module B should be selected.

[0088] The module propagation scheme is composed of the current battery module identifier to be activated, module activation order, target temperature, received power threshold, expected activation time, heating energy quota, effective heating power and remaining propagation heating energy, and then input into S420.

[0089] S420. Control the current battery module to be activated to perform propagation heating according to the module propagation scheme. The propagation heating energy is the upper limit of the total energy that can be used for heating subsequent battery modules, and the heating energy quota is the specific amount of energy allocated to the current battery module to be activated.

[0090] In actual operation, the vehicle controller prioritizes the extraction of heating power from the regenerative power currently generated by the drive motor, and inputs it into the battery module heating branch via the high-voltage DC bus and the corresponding module-level bidirectional conversion unit. The battery module heating branch includes a PTC electric heating film attached to the bottom of the battery module or an electric heating device built into the battery module. The remaining regenerative power continues to be allocated to the activated battery modules; when the current regenerative power is insufficient for a short period of time, only activated battery modules that are not in a charging state and have available discharge power are allowed to provide supplementary heating power, and charge and discharge state interlock is implemented to prohibit the same battery module from being charged and discharged at the same time in the same control cycle.

[0091] The target power for electric heating of the battery module to be activated is determined according to the following formula:

[0092] In the formula, The target power for electric heating is expressed in kW. Rated power of the battery module heating branch, in kW; The allowable output power for the heating direction of the module-level bidirectional conversion unit, in kW; The allocable regenerative power is the current regenerative power minus the necessary received power of the activated battery module, expressed in kW. Remaining heating energy, in kWh; The remaining time before the planned activation completion time, in hours.

[0093] Every 100ms, the minimum temperature, maximum temperature, available charging power, remaining rechargeable energy, single-cell voltage margin, and fault status of the battery module to be activated are read. The actual heating energy consumed is accumulated based on the actual voltage and actual current at the input terminal of the battery module's heating branch. The accumulation is performed using the same J to kWh conversion as S320.

[0094] After the minimum temperature reaches the target temperature range, the power of the electric heating is reduced cycle by cycle. When the minimum temperature is not lower than the target temperature, the available charging power is not lower than the received power threshold, the remaining rechargeable energy is not lower than the expected regenerative energy allocated after activation, the individual cell voltage margin meets the requirements, the maximum temperature does not exceed the limit, and there are no faults, and these conditions are met for three consecutive control cycles, a module activation confirmation signal is generated. If the actual heating energy consumed reaches the heating energy quota but the target temperature is still not reached, the expected activation time exceeds the remaining regenerative braking time, or a safety fault occurs, heating is stopped and a module activation failure signal is generated.

[0095] Input the signal type, current battery module identifier to be activated, minimum temperature, maximum temperature, available charging power, remaining rechargeable energy, single cell voltage margin, actual heating energy consumed, remaining heating energy, effective heating power, planned activation completion time, and remaining propagation heating energy into S430.

[0096] S430: Update the set of activated battery modules based on the signal output from S420 and determine the regenerative power allocation ratio. Upon receiving a module activation confirmation signal, add the currently activated battery module to the set of activated battery modules; upon receiving a module activation failure signal, do not add it, remove the battery module from the list of activatable battery modules, and return to S410 to re-determine the battery module to be activated. If an activated battery module subsequently experiences issues such as single-cell voltage exceeding limits, temperature exceeding limits, charging usable power dropping to 0, or a module-level bidirectional converter unit failure, remove it from the set.

[0097] The effective receiving capability of each activated battery module is determined by the following formula:

[0098] In the formula, The effective receiving capacity of the i-th activated battery module is expressed in kW. The available charging power for the i-th battery module, in kW; The allowed input power for the module-level bidirectional converter unit corresponding to the i-th battery module in the charging direction, in kW; Real-time remaining rechargeable energy, in kWh; The remaining regenerative braking time is expressed in hours (h).

[0099] The sum of the effective receiving capabilities of each module is determined as the total effective receiving capability of the activated battery module set, and the regenerative power allocation ratio is determined according to the proportion of each effective receiving capability to the total effective receiving capability. The power exceeding the effective receiving capability of a single battery module is redistributed, and the part that still cannot be allocated is consumed by the auxiliary braking device.

[0100] The module propagation status is composed of the set of activated battery modules, the set of unactivated battery module identifiers, the current battery module identifier to be activated, each effective receiving capability, the regeneration power allocation ratio, the total effective receiving capability, the remaining heating energy, the effective heating power, the planned activation completion time, the remaining propagation heating energy, the remaining expected regeneration energy, the activation failure reason, and the judgment result of whether to continue module propagation, and is then input into S510.

[0101] S5 specifically includes the following sub-steps: S510: Read the module propagation status and generate the current cycle energy allocation command. The current cycle energy allocation command is the set of target values ​​sent to each execution controller within the current 100ms control cycle.

[0102] The vehicle controller reads the set of activated battery modules, the effective receiving capacity of each module, the regenerative power allocation ratio, the total effective receiving capacity, the remaining heating energy of the currently activated battery modules, the effective heating power, the planned activation completion time, the remaining propagation heating energy, the remaining expected regenerative energy, and the judgment result on whether to continue module propagation; it reads the vehicle braking power demand and the allowable braking power of the auxiliary braking device from the brake controller, the upper limit of the power generation from the drive motor controller, and the actual net output power and allowable power change parameters from the fuel cell controller.

[0103] The control priorities are, in order: vehicle braking safety, high-voltage system safety, battery module charging boundary, power superposition not exceeding the total effective receiving capacity, increasing regenerative receiving capacity, and retaining propagation heating power with positive propagation net benefit.

[0104] Update the remaining charging power of the fuel cell using the same calculation method as S310, and determine the available regenerative receiving power of the activated battery module set:

[0105] In the formula, The available regenerative receiving power for the set of activated battery modules, in kW; The total effective receiving capacity of the activated battery module set, in kW; The remaining charging power of the fuel cell, in kW; This represents a safety margin for charging power, measured in kW.

[0106] The target power for propagation heating is determined according to the remaining heating energy, effective heating power, and planned activation completion time of the current battery module to be activated, following the electric heating target power calculation method of S420. If there is no current battery module to be activated or the judgment result for whether to continue module propagation is negative, the target power for propagation heating is set to 0.

[0107] The target regenerative power of the drive motor is determined by the following formula:

[0108] In the formula, The target regenerative power of the drive motor, in kW; The braking power required by the vehicle is expressed in kW. This is the upper limit of the generator power of the drive motor, in kW; The target heating power is measured in kW.

[0109] The target regenerative receiving power of the sodium-ion battery pack is the smaller of the non-negative value of the target regenerative power of the drive motor minus the target power of propagation heating and the available regenerative receiving power of the set of activated battery modules, excluding the remaining charging power of the fuel cell.

[0110] The target charging power for each activated battery module is determined according to the regeneration power allocation ratio, and the target charging current is calculated:

[0111] In the formula, The target charging current for the i-th activated battery module, in A; Target charging power, in kW; This is the battery module terminal voltage, in volts (V). The coefficient for converting kW to W.

[0112] The target charging current is limited by the battery management system's allowed charging current and the module-level bidirectional converter's allowed current, and the remaining power resulting from the limitation is redistributed. The target net output power of the fuel cell is reduced to the minimum net output power according to the allowed power reduction rate. The target power for auxiliary braking is the difference between the vehicle's braking power requirement and the drive motor's target regenerative power, and must not exceed the allowable braking power of the auxiliary braking device.

[0113] The target net output power of the fuel cell, the target regenerative power of the drive motor, the target regenerative receiving power of the sodium-ion battery pack, the target power of propagation heating, the target charging current of each target, and the target power of auxiliary braking are combined to form the energy distribution command for the current cycle, and input into S520.

[0114] S520: Execute the current cycle energy allocation command and establish a real-time energy allocation status. The vehicle controller sends each target value to the corresponding controller. When the regenerative receiving capability decreases, first increase the auxiliary braking target power, then decrease the drive motor target regenerative power; when the regenerative receiving capability increases, first confirm that the charging channel has been established, then increase the drive motor target regenerative power and simultaneously decrease the auxiliary braking target power.

[0115] Each control cycle reads the actual net output power from the fuel cell controller, the actual negative torque and speed from the drive motor controller and calculates the actual regenerative power, the battery module terminal voltage and actual charging current from each module-level bidirectional converter unit, the minimum temperature, maximum temperature, single cell voltage margin, available charging power, remaining rechargeable energy and fault status from the battery management system, the actual heating voltage and actual heating current from the battery module heating branch and calculates the actual heating power, and the actual auxiliary braking power and brake temperature from the brake controller.

[0116] Target values ​​must not replace actual values; when the deviation between the target regenerative power and the actual regenerative power of the drive motor exceeds the allowable tracking error, the remaining expected regenerative energy shall be updated using the actual regenerative power. If any activated battery module experiences a single cell voltage exceeding the limit, temperature exceeding the limit, charging available power dropping to 0, or a module-level bidirectional converter unit failure, the allocation of charging current to it shall be immediately stopped, it shall be removed from the activated battery module set, and the auxiliary braking target power shall be increased first, followed by a decrease in the drive motor target regenerative power.

[0117] The battery module screening, propagation heating, and set update are re-executed only when the judgment result of whether to continue module propagation is yes, there are still unactivated battery modules, the remaining propagation heating energy is sufficient to meet at least one heating energy quota, the remaining regeneration braking time is sufficient to complete activation, and the remaining expected regeneration energy is greater than the energy that the set of activated battery modules can continue to receive. At most one currently unactivated battery module is started in the same control cycle.

[0118] The actual net output power of the fuel cell, the actual regenerative power of the drive motor, the actual regenerative receiving power of the sodium-ion battery pack, the actual propagation heating power, the actual charging current of each battery module, the actual auxiliary braking power, the updated set of activated battery modules, the status of the battery modules to be activated, the remaining propagation heating energy, the remaining expected regenerative energy, the fault status, and the module propagation execution status are combined to form the real-time energy allocation status, and input into S530.

[0119] S530. Determine whether to end the current regenerative braking process based on the real-time energy distribution status. The regenerative braking process ends when the vehicle ceases to execute regenerative energy reception and module propagation control corresponding to the current road gradient sequence. The regenerative braking process is considered to have ended when: the vehicle position reaches the expected end point of regenerative braking; the traction system power demand for three consecutive road segments is not less than 0; the driver releases the brake pedal and the target torque of the drive motor is not less than 0 for three consecutive control cycles; a change in the navigation route causes the original remaining road gradient sequence to become invalid; or the vehicle speed falls below a preset low-speed threshold.

[0120] If the termination condition is not met, the actual net output power of the fuel cell, the actual regenerative power of the drive motor, the real-time status of each battery module, the set of activated battery modules, the status of the battery modules to be activated, the remaining propagation heating energy, the remaining expected regenerative energy, the module propagation execution status, and the updated remaining road slope sequence are fed back to S510.

[0121] When the termination condition is met, the target regenerative power of the drive motor is gradually reduced according to the allowable torque change rate of the drive motor, and the braking force difference during the transition period is compensated by the auxiliary braking device; after the vehicle no longer needs braking, the auxiliary braking power is gradually withdrawn.

[0122] The incomplete propagation heating is stopped, the heating branch of the corresponding battery module is disconnected, and the activation process, which has no further receiving value, is not consumed by the sodium-ion battery pack. Based on the power demand of the traction system of the subsequent road, the fuel cell is controlled to resume power supply at the allowable power increase rate, with the sodium-ion battery pack compensating for the traction power gap during the fuel cell recovery period.

[0123] The actual power change records of the fuel cell, the activation sequence of each battery module, the amount of regenerative energy received by each battery module, the amount of propagation heating energy consumed, the amount of auxiliary braking energy consumed, the amount of unreceived regenerative energy, and the fault records are combined to form the energy distribution management results, which are stored in the vehicle controller for the correction of prediction parameters and the diagnosis of battery module heating performance in the same road section.

[0124] Example 2: Figure 2 As shown, this embodiment provides a multi-objective energy distribution management system for a fuel cell-sodium-ion battery hybrid heavy-duty tractor, including: Fuel cells, sodium-ion battery packs, drive motors, auxiliary braking devices, a whole-pack bidirectional DC-DC converter, a vehicle controller, and module-level bidirectional converter units, battery module heating circuits, and controllable heat exchange circuits corresponding to each battery module. The vehicle controller includes: The information acquisition and prediction module is used to acquire vehicle operation data, fuel cell operation data, status data of each battery module and road ahead data, and predict the power polarity switching time, regenerative braking power demand and power polarity isolation range. The isolation activation module is used to screen and select seed battery modules, control the fuel cell to reduce net output power, compensate for the traction power gap by sodium-ion battery pack, and use the remaining electric power and waste heat of fuel cell to heat seed battery modules. The first-stage regeneration control module is used to determine the regeneration braking opening conditions based on the remaining charging power of the fuel cell, the available charging power of the seed battery module, the remaining rechargeable energy, and the single-cell voltage margin, and to control the drive motor to establish regeneration braking and enable the seed battery module to receive the first-stage regeneration energy. The module propagation module is used to determine the battery modules to be activated and the module activation order, allocate propagation heating power from the regenerative power of the drive motor, and add the battery modules to be activated that meet the receiving conditions to the set of activated battery modules. The collaborative allocation module is used to adjust the target net output power of the fuel cell, the target regenerative power of the drive motor, the target charging current of each activated battery module, the target power of propagation heating, and the target power of auxiliary braking based on the total effective receiving capacity of the activated battery module set, the remaining expected regenerative energy, and the vehicle braking demand.

[0125] like Figure 3 As shown, the fuel cell stack 100 is connected to the high-voltage DC bus 200 via the fuel cell DC-DC converter 110, and the drive motor 310 is bidirectionally connected to the high-voltage DC bus 200 via the motor inverter 300. The whole-pack bidirectional DC-DC converter 400 is connected between the high-voltage DC bus 200 and the common DC link 410 on the battery pack side. The sodium-ion battery modules 431, 432, 43n and their battery module heating branches 441, 442, 44n are respectively connected to the common DC link 410 on the battery pack side via the corresponding module-level bidirectional converter units 421, 422, 42n. The vehicle controller 600 interacts with the fuel cell DC-DC converter 110, the motor inverter 300, the whole-pack bidirectional DC-DC converter 400, each module-level bidirectional converter unit, the battery management system 610, the brake controller 620, the vehicle navigation and global navigation satellite system 630, the accessory controller 640, and the thermal management controller 780 for control or status information exchange.

[0126] like Figure 4 As shown, the high-temperature cooling circuit of the fuel cell and the low-temperature coolant circuit of the sodium-ion battery module are physically isolated through a water-to-water heat exchanger 740. The thermal management controller 780 adjusts the high-temperature coolant pump 710, the three-way proportional valve 720, the battery-side coolant pump 750, and the controllable heat exchange branch valves 771, 772, and 77n based on the detection signals from the temperature, flow rate, and valve position sensors 790. This allows the low-temperature coolant, which has absorbed waste heat from the fuel cell through the water-to-water heat exchanger 740, to enter the target sodium-ion battery module through the supply distribution pipe 760 and return to the water-to-water heat exchanger 740 through the return manifold 765. The battery module heating branches 441, 442, and 44n electrically heat the corresponding battery modules either by attachment or by embedding, and are not connected in series with the low-temperature coolant circuit.

[0127] All the above formulas are calculated according to the physical quantities and corresponding units listed in the formulas. When the units of the collected data are inconsistent with the units used in the formulas, the collected data are first converted to the units specified in the formulas before being substituted into the corresponding formulas for calculation. Among the above formulas, those based on vehicle dynamics, electric power balance, energy conservation, and time integral relationships are calculated according to the corresponding physical relationships. The contents involving calibration charts, preset parameters, thresholds, and correction coefficients are determined by bench tests of vehicles or core components, whole vehicle calibration tests, and historical operating data, and are pre-stored in the corresponding controllers. Those skilled in the art can perform routine calibration and adjustment according to the rated parameters, operating conditions, and safety boundaries of the power system of a specific vehicle model.

[0128] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0129] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0130] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-objective energy distribution management method for sodium-hydrogen composite power heavy-duty trucks, characterized in that, Includes the following steps: S1. Obtain vehicle speed, traction system power demand, road gradient sequence, fuel cell net output power, battery module temperature, available charging power and single cell voltage margin, and predict power polarity switching time, regenerative braking power demand and power polarity isolation range. S2. Select the seed battery module within the power polarity isolation range, control the fuel cell to reduce the net output power, use the sodium-ion battery pack to compensate for the traction power gap, and use the remaining power and waste heat of the fuel cell to heat the seed battery module so that it reaches the first stage of regenerative energy receiving conditions. S3. Determine the regenerative braking opening conditions based on the remaining charging power of the fuel cell, the available charging power of the seed battery module, the remaining rechargeable energy, and the single cell voltage margin. Control the drive motor to establish regenerative braking and distribute the first stage of regenerative energy to the seed battery module. S4. Determine the battery modules to be activated and their activation order based on the activation heating energy, expected activation time and effective receiving capability of the unactivated battery modules, allocate the propagation heating power from the regeneration power to the battery modules to be activated, and add them to the set of activated battery modules when they reach the receiving conditions. S5. Based on the total effective receiving capacity of the activated battery module set, the remaining expected regenerative energy, and the vehicle braking demand, adjust the target net output power of the fuel cell, the target regenerative power of the drive motor, the target charging current of each activated battery module, the target power of propagation heating, and the target power of auxiliary braking until the regenerative braking process is completed.

2. The method for multi-objective energy distribution management of a sodium-hydrogen composite power heavy-duty truck according to claim 1, characterized in that, S1 specifically includes: Acquire vehicle load, real-time vehicle speed, drive motor operating data, fuel cell net output power and allowable power drop rate, on-board accessory power, status data of each battery module and road ahead data, and perform time alignment on the data to form a basic operating dataset. The traction system power demand at each predicted location on the road is calculated based on the basic operation dataset. The absolute value of the negative value is determined as the predicted regenerative braking power. Combined with the fuel cell's allowable power decline rate, the predicted power polarity switching time and the fuel cell's residual power, a polarity switching prediction result is formed.

3. The method for multi-objective energy distribution management of a sodium-hydrogen composite power heavy-duty truck according to claim 2, characterized in that, Also includes: Based on the polarity switching prediction results, identify the power overlap period, determine the power polarity isolation interval, fuel cell power reduction benchmark, sodium-ion battery pack traction compensation requirement, first-segment received power threshold and first-segment regenerative energy requirement, and form an isolation control benchmark.

4. The method for multi-objective energy distribution management of a sodium-hydrogen composite power heavy-duty truck according to claim 1, characterized in that, S2 specifically includes: Based on the isolation control benchmark, candidate battery modules are screened according to the state of charge, state of health, minimum temperature, internal resistance, available charging power, remaining rechargeable energy and single-cell voltage margin of each battery module. The target temperature and activation heating energy are determined, and the seed battery module is selected. Based on the target temperature and activation heating energy of the seed battery module, a power transition scheme is generated, including the target net output power of the fuel cell, the target power of the sodium-ion battery pack traction compensation, the target power of electric heating, and the target power of waste heat transfer. The net output power of the fuel cell is reduced according to the power transition scheme, and the seed battery module is heated by electric power and waste heat. When its available charging power, remaining rechargeable energy, single cell voltage margin, temperature and fault status meet the conditions for receiving the first stage of regenerative energy, the isolation execution result is formed.

5. The method for multi-objective energy distribution management of a sodium-hydrogen composite power heavy-duty truck according to claim 1, characterized in that, S3 specifically includes: Based on the isolation execution results, the remaining charging power of the fuel cell is calculated. Combined with the available charging power, remaining rechargeable energy and single cell voltage margin of the seed battery module, the regenerative braking opening condition is determined and the first segment of regenerative power trajectory is generated. The drive motor is controlled to establish regenerative braking according to the trajectory of the first regenerative power, and the first regenerative energy is distributed to the seed battery module. The auxiliary braking power is adjusted according to the actual regenerative power, and the received power, received regenerative energy and operating status are collected to form the first regenerative reception result.

6. The method for multi-objective energy distribution management of a sodium-hydrogen composite power heavy-duty truck according to claim 5, characterized in that, Also includes: Based on the initial regeneration reception results, the regeneration power that can continue to be received, the propagation heating energy, and the remaining expected regeneration energy are determined. Propagation trigger data is generated when the receiving capacity of the seed battery module is insufficient.

7. The method for multi-objective energy distribution management of a sodium-hydrogen composite power heavy-duty truck according to claim 1, characterized in that, S4 specifically includes: Based on the propagation trigger data, the activation heating energy, expected activation time, remaining rechargeable energy, single-cell voltage margin, and effective receiving capability of each unactivated battery module are used to screen the battery modules that can be activated, determine the battery modules to be activated and the module activation order, and form a module propagation scheme. According to the module propagation scheme, the propagation heating power is allocated from the regenerative power of the drive motor to the battery module heating branch of the battery module to be activated, and a module activation confirmation signal or a module activation failure signal is generated based on its minimum temperature, maximum temperature, available charging power, remaining rechargeable energy and single cell voltage margin. The set of activated battery modules is updated based on the module activation confirmation signal. The effective receiving capability of each activated battery module is calculated and the regeneration power allocation ratio is determined to form the module propagation status.

8. The method for multi-objective energy distribution management of a sodium-hydrogen composite power heavy-duty truck according to claim 1, characterized in that, S5 specifically includes: Based on the module propagation status, vehicle braking power demand, drive motor power generation limit, fuel cell remaining charging power, and total effective receiving capacity of activated battery modules, determine the target net output power of the fuel cell, the target regenerative power of the drive motor, the target propagation heating power, the target charging current, and the target auxiliary braking power. The system executes target power and target charging current, collects data from fuel cells, drive motors, each battery module, battery module heating branches, and auxiliary braking devices, and adjusts energy distribution based on effective receiving capability and fault status to form a real-time energy distribution status.

9. The method for multi-objective energy distribution management of a sodium-hydrogen composite power heavy-duty truck according to claim 8, characterized in that, Also includes: The regenerative braking process is determined based on the real-time energy distribution status. If it is not finished, updated data is fed back. If it is finished, the propagation heating is stopped, the drive motor is controlled to exit the regenerative braking and the fuel cell power supply is restored, thus forming the energy distribution management result.

10. A multi-objective energy distribution management system for a sodium-hydrogen composite power heavy-duty truck, employing the multi-objective energy distribution management method for a sodium-hydrogen composite power heavy-duty truck as described in any one of claims 1 to 9, characterized in that, include: Fuel cell, sodium-ion battery pack, drive motor, auxiliary braking device, whole pack bidirectional DC-DC converter, vehicle controller, and module-level bidirectional converter, battery module heating branch and controllable heat exchange branch corresponding to each battery module.

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