A method, system and vehicle for energy balance control of a fuel cell
By acquiring preset input signals and operating condition control modes, the SOC balance control stage of the fuel cell is determined, and target power optimization is performed. This solves the problem of slow power following response speed in fuel cell systems and achieves efficient energy balance control and improved safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG GEELY HLDG GRP CO LTD
- Filing Date
- 2023-06-08
- Publication Date
- 2026-07-14
AI Technical Summary
In existing fuel cell systems, the slow power follow-up response speed contradicts the energy demand of the vehicle, resulting in high costs and difficulty in achieving energy balance control.
By acquiring preset input signals, the SOC balance control stage of the fuel cell is determined, and the target power is optimized in combination with the operating condition control mode to achieve the energy balance control of the fuel cell, including active control of stages such as fast overcharge, slow overcharge, fast over-discharge and slow over-discharge.
It achieves efficient energy balance control of fuel cells, reduces energy fluctuations in the vehicle, improves battery safety and driving performance, and solves the dual high cost problem of large stack power and large battery capacity.
Smart Images
Figure CN116901790B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power battery technology, and more specifically, to a fuel cell energy balance control method, system, and vehicle. Background Technology
[0002] With the energy and environmental situation becoming increasingly severe, the development of new energy vehicles has received more and more attention. Fuel cells, with their unique energy-saving and environmental protection advantages, have been extensively studied by developers. Taking hydrogen fuel cells as an example, they have the characteristics of low operating temperature, high power density, fast response speed and low environmental pollution.
[0003] However, the power response speed of hydrogen fuel cells is significantly lower than that of traditional engines and fuel cells. This leads to a sharp contradiction between the power size of the fuel cell stack and the capacity of the fuel cell and the cost and performance of the vehicle. If a high-power fuel cell stack is matched, a relatively large-capacity fuel cell is needed to accommodate the energy fluctuations caused by the slow power response of the fuel cell stack. If a low-power fuel cell stack is matched, a very large-capacity fuel cell is still needed to provide energy for the vehicle, which is not conducive to energy conservation, emission reduction and cost control. Summary of the Invention
[0004] The problem addressed by this invention is how to achieve efficient energy balance control in fuel cells.
[0005] To address the aforementioned problems, this invention provides a method, system, and vehicle for energy balance control of fuel cells.
[0006] In a first aspect, the present invention provides an energy balance control method for a fuel cell, comprising:
[0007] Acquire a preset input signal and determine the SOC balance control stage of the fuel cell based on the preset input signal;
[0008] The operating condition control mode is identified based on the preset input signal and the SOC balance control stage.
[0009] The target power is optimized based on the SOC balance control stage and the operating condition control mode to determine the target power and target power output duration of the fuel cell.
[0010] Optionally, the preset input signal includes the current SOC value, the rapid overcharge SOC threshold, and the rapid over-discharge SOC threshold, and the step of determining the SOC balance control stage of the fuel cell based on the preset input signal includes:
[0011] If the current SOC value is greater than the lower limit of the equilibrium SOC and less than the fast overcharge SOC threshold, the fuel cell enters the battery fast overcharge control stage.
[0012] When the fuel cell is in the fast overcharge control stage, if the current SOC value reaches the fast overcharge SOC threshold, the fuel cell enters the slow overcharge control stage.
[0013] When the fuel cell is in the slow overcharge control stage, if the current SOC value reaches the upper limit of the balanced SOC, the fuel cell enters the fast over-discharge control stage.
[0014] When the fuel cell is in the fast over-discharge control stage, if the current SOC value reaches the fast over-discharge SOC threshold, the fuel cell enters the slow over-discharge control stage.
[0015] Optionally, the preset input signal includes a throttle signal and a vehicle power signal, and the step of identifying the operating condition control mode based on the preset input signal and the SOC balance control stage includes:
[0016] The operating condition control mode is identified based on the throttle signal, the vehicle power signal, and the SOC balance control stage. The operating condition control mode includes idle mode, constant power mode, rapid power change mode, alternating power mode, and low power mode.
[0017] Optionally, the target power optimization based on the SOC balance control stage and the operating condition control mode includes:
[0018] Estimate the energy change value of the fuel cell based on the operating condition control mode;
[0019] The remaining charging and discharging times of the fuel cell are estimated based on the energy change value, the SOC balance control stage, and the battery balance cutoff energy.
[0020] Target power optimization is performed based on the operating condition control mode, the remaining charging time, the remaining discharging time, and the fuel cell's charge level.
[0021] Optionally, the step of optimizing the target power based on the operating condition control mode, the remaining charging time, the remaining discharging time, and the fuel cell's charge includes:
[0022] The current target power is determined based on the operating condition control mode, the remaining charging time, the remaining discharging time, and the fuel cell's charge level.
[0023] Estimate the target power response time based on the current target power;
[0024] The target power and the target power output duration are determined based on the target power response time.
[0025] Optionally, the target power optimization based on the SOC balance control stage and the operating condition control mode further includes: determining the initial value of the target power and the power change step size.
[0026] Optionally, the target power optimization based on the SOC balance control stage and the operating condition control mode further includes: limiting the target power extreme value, limiting the change gradient, and resetting the power change.
[0027] Optionally, the energy balance control method for the fuel cell further includes: estimating the power of vehicle accessories, the power of the vehicle, and the power of the fuel cell to estimate the energy fluctuation value of the fuel cell, and using the energy fluctuation value as the energy balance control target of the fuel cell.
[0028] Secondly, the present invention provides an energy balance control system for a fuel cell, comprising a computer-readable storage medium storing a computer program and a processor, wherein the computer program is read and executed by the processor to implement the above-mentioned energy balance control method for the fuel cell.
[0029] Thirdly, the present invention provides a vehicle including the energy balance control system of the aforementioned fuel cell.
[0030] After determining the SOC balance control stage and identifying the operating condition control mode of the fuel cell, this invention optimizes the target power through the SOC balance control stage and the operating condition control mode, thereby determining the target power and target power output duration of the fuel cell as the fuel cell power control target. This enables active overcharge and over-discharge energy control, such as controlling the overcharge and over-discharge energy range, achieving efficient fuel cell energy balance control. This solves the dual high cost problem of large stack power and large battery capacity in existing fuel cell vehicles, while also improving battery safety and vehicle driving performance. Attached Figure Description
[0031] Figure 1 This is a schematic flowchart of the energy balance control method for a fuel cell according to an embodiment of the present invention;
[0032] Figure 2 This is a schematic diagram of the framework of the energy balance control method for fuel cells according to an embodiment of the present invention;
[0033] Figure 3 This is a schematic diagram of the framework of the fuel cell target power optimization algorithm according to an embodiment of the present invention;
[0034] Figure 4 This is a schematic diagram illustrating the principle of the energy balance control method for fuel cells according to an embodiment of the present invention. Detailed Implementation
[0035] Most existing hydrogen fuel cell electric vehicles are equipped with a large-capacity power battery, which greatly reduces the limitations on the accuracy and performance of power battery balance control, thereby significantly reducing the difficulty of power balance control technology. Alternatively, hydrogen fuel cells can be made into a type of micro-hybrid similar to hybrid vehicles (i.e., equipped with a small-capacity power battery, such as 2kWh or 4kWh), where a high-power stack is matched with a small-capacity battery. This achieves a good balance between energy saving, emission reduction, and cost. However, to achieve this, balancing the power of the entire vehicle, the power of the stack, and the power of the battery becomes the most critical control objective and technical challenge. To achieve the above technology, this invention proposes an energy balance control method for fuel cells, namely, an energy balance control method based on active overcharge and over-discharge energy control at the power battery's state of charge (SOC) point.
[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0037] like Figure 1 As shown, an embodiment of the present invention provides an energy balance control method for a fuel cell, comprising:
[0038] Acquire a preset input signal and determine the SOC balance control stage of the fuel cell based on the preset input signal.
[0039] Specifically, a preset input signal is first acquired, and the SOC balance control stage of the fuel cell (hereinafter also referred to as the battery control stage) is determined based on the preset input signal. The SOC balance control stage includes, but is not limited to:
[0040] (1) Battery fast overcharge control stage: This control process actively guides the battery to be under high current overcharge control, and actively changes the target power of the battery stack towards the trend of making the battery fast overcharge.
[0041] (2) Battery slow overcharge control stage: This control process actively guides the battery to be under low current overcharge control. The target power of the battery stack is actively changed towards the trend of slow overcharging of the battery, so as to actively and effectively control the battery cut-off overcharge energy value.
[0042] (3) Battery fast over-discharge control stage: This control process actively guides the battery to be under high current over-discharge control, and actively changes the target power of the stack to make the battery over-discharge quickly.
[0043] (4) Battery slow over-discharge control stage: This control process actively guides the battery to be under low current over-discharge control. The target power of the battery stack is actively changed towards the trend of slow over-discharge of the battery, so as to actively and effectively control the battery cut-off over-discharge energy value.
[0044] The preset input signals may include, but are not limited to: battery SOC (State of Charge), battery energy, battery current, battery voltage, battery discharge capacity power, battery charging capacity power, compressor power, DC-DC power, PTC (Positive Temperature Coefficient, which in automobiles refers to the car heater) power, vehicle drive power, vehicle regeneration power, total battery stack power, battery stack capacity power, throttle signal, vehicle speed signal, parking signal, and gear signal.
[0045] The operating condition control mode is identified based on the preset input signal and the SOC balance control stage.
[0046] Specifically, in combination Figure 2 and Figure 3 As shown, the battery SOC balancing stage control module determines the current control stage of the battery SOC balancing, i.e., the SOC balancing control stage. Combined with the preset input signal, the control mode of the current operating condition can be identified, i.e., the operating condition control mode. Since the target power calculation of the specific fuel cell needs to take into account the characteristics of the current operating condition, different operating conditions have a great impact on the power balance of the whole vehicle and the target power calculation of the fuel cell. The operating condition control mode can be divided into idle mode, constant power mode, rapid power mode, alternating power mode and low power mode according to the different operating condition power models of the whole vehicle.
[0047] The target power is optimized based on the SOC balance control stage and the operating condition control mode to determine the target power and target power output duration of the fuel cell.
[0048] Specifically, in combination Figure 2 and Figure 3 As shown, after identifying the operating condition control mode, the fuel cell target power and duration control estimation module uses the current SOC balance control stage and the identified operating condition control mode to find the target power and output duration of the fuel cell as the battery energy balance fuel cell power control target. Due to the lag in fuel cell power tracking, the fuel cell cannot accurately provide energy fluctuation tracking under various vehicle operating conditions. Therefore, the power battery acts like a reservoir, and the energy management and balance of the vehicle can be achieved through battery overcharging or over-discharging. In this embodiment, the target power and duration of the fuel cell can be calculated backwards using the idea of active battery overcharging and overcharging. This transforms the existing fuel cell power calibration scheme into a scheme that can accurately deduce the fuel cell power and duration backwards from the battery target end.
[0049] Optionally, the preset input signal includes the current SOC value, the fast overcharge SOC threshold, and the fast over-discharge SOC threshold.
[0050] Specifically, the preset input signals include the current SOC value, the fast overcharge SOC threshold, and the fast over-discharge SOC threshold. The current battery SOC balance control stage can be determined by comprehensively considering the current SOC, energy, fast charge energy calibration value, fast discharge energy calibration value, and current operating condition control mode. The battery SOC balance stage control module includes: (1) SOC balance point and interval setting; (2) battery overcharge (discharge) stage target; (3) SOC balance cycle control; and (4) battery cutoff energy and balance energy. The preset input signals of the battery SOC balance stage control module include, but are not limited to, discharge capacity power, charging capacity power, battery SOC, battery energy, battery current, and operating condition control mode. The output of the battery SOC balance stage control module includes, but is not limited to, battery cutoff energy, battery balance energy value, and battery control stage.
[0051] To effectively and proactively control the balance range of a power battery, the normal practice is to set a balance SOC point and a balance range, and to proactively reduce or increase the power of the battery stack to compensate for any deviations from this range. However, in reality, changes in battery stack power cannot respond as quickly as those in an engine or power battery. Therefore, this design further subdivides the overcharge and over-discharge stages of the battery design. The overcharge stage is further divided into a fast overcharge stage and a slow overcharge stage, and the over-discharge stage is further divided into a fast over-discharge stage and a slow over-discharge stage.
[0052] Combination Figure 4 As shown, the energy difference E between the upper limit of the battery's balanced SOC (e.g., 65%) and the battery's SOC limit of 100% is... rc During calibration, E rc The value should take into account the magnitude of the vehicle's rapid recovery power, the maximum response gradient of the battery stack, the minimum power of the battery stack at idle, and the maximum recovery time of the vehicle; while the energy difference E between the lower limit of the equilibrium SOC (e.g., 60%) and the battery SOC limit of 0% should be considered. rd The value should take into account factors such as the magnitude of the vehicle's power during rapid full-throttle drive at the battery over-discharge cutoff SOC point, the maximum response gradient of the fuel cell stack, and the maximum driving duration of the vehicle. Combined with... Figure 4 As shown, in order to effectively control the SOC balance range of the power battery, four control zones for battery balance are actively set, and the four zones are switched crosswise according to the actual energy of the battery and the operating conditions of the vehicle. (Under normal circumstances, these four control phases are cyclically switched, but if the actual energy of the battery touches the fast overcharge point or fast over-discharge point, the control phase should be switched to the nearest operating condition or skipped according to the specific operating conditions).
[0053] The step of determining the SOC balance control stage of the fuel cell based on the preset input signal includes:
[0054] If the current SOC value is greater than the lower limit of the equilibrium SOC and less than the fast overcharge SOC threshold, then the fuel cell enters the battery fast overcharge control stage.
[0055] Specifically, in combination Figure 4 As shown, to balance the lower limit of SOC E low 60%, fast over-discharge SOC threshold E slow 61.5%, battery balance SOC line E sb The SOC threshold for rapid overcharge is 62.5%. fast It is 63.5% and the upper limit of the balanced SOC value E up Taking 65% as an example, if the current SOC value is greater than 60% and less than 63.5% (E0-E1-E2), the fuel cell enters the battery fast overcharge control stage (I). In this stage, the battery is actively guided to be under high current overcharge control. The maximum and minimum overcharge power are set as targets. Then, the target power of the fuel cell and the corresponding power duration are calculated from the vehicle power balance model under the current operating conditions and the overcharge power target.
[0056] When the fuel cell is in the fast overcharge control stage, if the current SOC value reaches the fast overcharge SOC threshold, the fuel cell enters the slow overcharge control stage.
[0057] Specifically, in combination Figure 4 As shown, when the fuel cell is in the fast overcharge control stage, if the current SOC value reaches 63.5% (as shown in E2), the fuel cell enters the slow overcharge control stage (II). In this stage, the battery is actively guided to be under low-current overcharge control. The maximum and minimum overcharge power are set as targets. Then, the target power of the fuel cell and the corresponding power duration are calculated from the vehicle power balance model under the current operating conditions and the overcharge power target. Different corrections are needed for the SOC cutoff point under different operating conditions to ensure that the battery does not exceed the upper limit of this SOC balance range. For example, when in slow overcharge control, when the operating condition enters rapid reduction or alternating recovery, the cutoff SOC should be predicted and contracted (reserved) to prevent the battery's actual SOC from exceeding the cutoff point.
[0058] When the fuel cell is in the slow overcharge control stage, if the current SOC value reaches the upper limit of the balanced SOC, the fuel cell enters the fast over-discharge control stage.
[0059] Specifically, in combination Figure 4As shown, when the fuel cell is in the slow overcharge control stage, if the current SOC value reaches 65% (position shown in E5), the fuel cell enters the fast over-discharge control stage (III). In this stage, the battery is actively guided to be in high current over-discharge control. The maximum and minimum over-discharge power are set as targets. Then, the target power of the fuel cell and the corresponding power duration are calculated from the vehicle power balance model under the current operating conditions and the over-discharge power target.
[0060] When the fuel cell is in the fast over-discharge control stage, if the current SOC value reaches the fast over-discharge SOC threshold, the fuel cell enters the slow over-discharge control stage.
[0061] Specifically, in combination Figure 4 As shown, when the fuel cell is in the fast over-discharge control stage, if the current SOC value reaches 61.5% (position shown in E7), the fuel cell enters the slow over-discharge control stage (IV) until the current SOC value reaches 60% (position shown in E8). During this stage, the battery is actively guided to be in low-current over-discharge control, and the maximum and minimum over-discharge power are set as targets. Then, the target power of the fuel cell and the corresponding power duration are calculated from the vehicle power balance model under the current operating condition and the over-discharge power target. Different corrections are needed for the SOC over-discharge cutoff point under different operating conditions to ensure that the battery does not exceed the lower value of this SOC balance range. For example, when in slow over-discharge control, when the operating condition enters rapid acceleration or alternating drive, the cutoff SOC should be pre-contracted (reserved) to prevent the battery's actual SOC from exceeding the lower limit.
[0062] Among them, the actual battery power is based on Figure 4 The dashed lines indicate E0-E8 ’ As shown.
[0063] Optionally, the preset input signal includes a throttle signal and a vehicle power signal, and the step of identifying the operating condition control mode based on the preset input signal and the SOC balance control stage includes:
[0064] The operating condition control mode is identified based on the throttle signal, the vehicle power signal, and the SOC balance control stage. The operating condition control mode includes idle mode, constant power mode, rapid power change mode, alternating power mode, and low power mode.
[0065] Specifically, in combination Figure 2 and Figure 3 As shown, the operating condition control mode can be identified by the throttle, vehicle power, control stage, and relevant information representing the vehicle's operating condition.
[0066] The inputs of the control mode recognition module include, but are not limited to: throttle signal, vehicle power at the battery end, vehicle power change status, total power of accessories, power change status of accessories, net output power of the battery stack, battery discharge capacity power, battery charging capacity power, battery SOC, actual battery energy and battery control stage. The output of the control mode recognition module is the operating condition control mode.
[0067] The operating condition control modes include:
[0068] (1) Idle speed control mode (continuous t) A This mode is primarily designed for actively controlling battery SOC balance while the battery stack is operating in a stationary state. When the power of the vehicle accessories is less than the minimum idle power of the battery stack, it charges directly to the SOC cutoff point and then stops. If the power of the vehicle accessories is greater than the minimum idle power of the battery stack, the battery stack meets the prerequisite of actively cyclically controlling battery balance without stopping. Under this condition, the battery stack performs cyclical control according to the power of the accessories, following the four control stages designed for the battery. During control, the battery stack can set a relatively fixed and stable power at each stage to achieve cyclical control of active overcharging and over-discharging of the battery, thereby achieving multi-cycle battery SOC balance control under idle conditions. The idle control mode must simultaneously meet the following conditions: accelerator pedal opening is 0, non-cruise mode, requested torque is 0, vehicle state is stationary, and the gear is neutral (N).
[0069] (2) Constant power control mode (continuous t) B This mode is mainly for controlling the energy balance of the battery by actively overcharging and over-discharging when the power of the whole vehicle and the power of accessories are in a relatively stable state (or with very small fluctuations), such as cruise control and smooth acceleration and deceleration of the vehicle. The power of the drive and accessories is relatively stable in this mode. The whole vehicle power model can be implemented by referring to the idle speed control method. The power of the battery stack can meet the requirements by increasing the whole vehicle power part and making some reserved power control under the idle speed power control method.
[0070] (3) Rapid power change control mode (continuous t) C +t DThis mode is mainly for situations where the power of vehicle accessories or drive power increases or decreases rapidly, such as during intense driving (without energy feedback). Based on the characteristics of this situation, specific parameter values need to be calibrated for the control targets of the battery and fuel cell stack to ensure both the vehicle's power requirements and the battery's energy balance control targets are met. Rapid power change control is for situations where drive or accessory power increases or decreases rapidly. Under these conditions, a power prediction estimation needs to be added to the constant power control mode to estimate the vehicle's power point after the rapid change. Simultaneously, the difference in vehicle power is used to appropriately correct the battery's overcharge or over-discharge power target during this stage, thus offsetting any inaccuracies in the vehicle power model estimation caused by the rapid change in vehicle power.
[0071] (4) Alternating power control mode (continuous t) E +t F Alternating power control mode primarily considers situations where the vehicle's power changes abruptly from driving to regenerative braking or vice versa, such as during aggressive driving (with significant energy recovery capability). This mode addresses the characteristics of this condition by differentiating the calibration settings for battery overcharging or over-discharging, and also differentiates the power change frequency of the battery stack. Alternating power control is a special case of rapid power control. Its biggest difference from rapid power control is that the vehicle's power not only changes abruptly, but also changes from positive to negative, or vice versa. Its control requires timely adjustment of the target power change gradient of the battery stack before the power sign changes in rapid power control, using the maximum change gradient and based on E... rc or E rd Appropriate maximum and minimum target power limits for the fuel cell stack should be used to accommodate the vehicle drive and recycling requirements under this condition.
[0072] (5) Low power control mode (continuous t) G +t H +t IThis mode is a commonly used control mode during driving, characterized by lower vehicle power and frequently changing power demands, such as in long-range mode (speed and power limited). For this condition, the energy integral term is given greater weight in the target power calculation compared to other modes. This is to effectively control the cumulative effect caused by frequent dynamic energy changes, which could compromise battery balance.
[0073] Optionally, the target power optimization based on the SOC balance control stage and the operating condition control mode includes:
[0074] The energy change value of the fuel cell is estimated based on the operating condition control mode.
[0075] Specifically, in combination Figure 3 As shown, after the control mode recognition module identifies the operating condition control mode, the battery energy change estimation module determines the energy fluctuation of the battery estimated by the vehicle power model under the current operating condition control mode, that is, the energy change value of the fuel cell.
[0076] The inputs to the battery energy change estimation module include, but are not limited to: throttle signal, vehicle power at the battery end, vehicle power change status, total power of accessories, power change status of accessories, net output power of the battery stack, battery discharge capacity power, battery charging capacity power, battery SOC, and actual battery energy.
[0077] The remaining charging and discharging times of the fuel cell are estimated based on the energy change value, the SOC balance control stage, and the battery balance cutoff energy.
[0078] Specifically, in combination Figure 3 As shown, the battery charging (discharging) remaining time estimation module calculates the remaining time to reach the overcharge and over-discharge cutoff based on the estimated battery energy change value, battery control stage, and battery balance cutoff energy, which serves as one of the judgment conditions for subsequently changing the calculated target power.
[0079] Target power optimization is performed based on the operating condition control mode, the remaining charging time, the remaining discharging time, and the fuel cell's charge level.
[0080] Specifically, in combination Figure 3As shown, the target power optimization judgment and control module calculates the starting value of the target power sequence for optimization calculation and manages the power optimization step size by using relevant signals such as the current target power, operating condition control mode, remaining charging (discharging) time, and battery power. At the end of the optimization, it determines whether the optimization has ended, thereby realizing target power optimization.
[0081] The inputs to the target power optimization judgment and control module include, but are not limited to: fuel cell target power (assumed), target power, power duration, battery control stage, operating condition control mode, remaining charging time, remaining discharging time, battery change energy, battery cutoff energy, battery balance energy, and battery SOC. When performing the judgment, the target power optimization judgment and control module mainly considers: remaining charging and discharging time, fuel cell power response gradient, battery control stage, operating condition control mode, fuel cell target power duration, the difference between power duration and remaining time, battery change energy value, battery cutoff energy, battery balance energy, actual battery SOC, and estimated SOC.
[0082] Optionally, the step of optimizing the target power based on the operating condition control mode, the remaining charging time, the remaining discharging time, and the fuel cell's charge includes:
[0083] The current target power is determined based on the operating condition control mode, the remaining charging time, the remaining discharging time, and the fuel cell's charge level.
[0084] Specifically, in combination Figure 3 As shown, the fuel cell target power module is used to determine the current target power, i.e., the fuel cell target power (assumed), based on the remaining charging time and remaining discharging time provided by the battery charging (discharging) remaining time estimation module, as well as the aforementioned operating condition control mode and battery control stage.
[0085] Other inputs to the fuel cell target power module include, but are not limited to: net output power of the fuel cell stack, power gradient of the fuel cell stack, vehicle power at the battery end, total power of accessories, battery energy, and battery SOC. When estimating the target power module of the fuel cell, the following are mainly considered: estimated remaining charging (discharging) time, battery control stage, current operating condition control mode, actual power of the fuel cell, power change gradient of the fuel cell, vehicle power and status at the battery end, power and status of vehicle accessories, actual battery energy and SOC, and target power related signals (initial power, power step size, etc.).
[0086] The target power response time is estimated based on the current target power.
[0087] Specifically, in combination Figure 3 As shown, the target power response time estimation module can estimate the target power response time based on the target power (assumed) of the fuel cell.
[0088] Other inputs to the target power response time estimation module include, but are not limited to: battery control stage, operating condition control mode, net output power of the fuel cell stack, and power change gradient of the fuel cell stack. When performing the estimation, the target power response time estimation module mainly considers: battery control stage, operating condition control mode, actual output power of the fuel cell stack, power change gradient of the fuel cell stack, response time limit, and reset.
[0089] The target power and the target power output duration are determined based on the target power response time.
[0090] Specifically, in combination Figure 3 As shown, the target power duration calculation module determines the target power and the target power output duration based on the target power response time provided by the target power response time estimation module.
[0091] Other inputs to the target power duration calculation module include, but are not limited to: battery control stage, operating condition control mode, battery stack net output power, battery cutoff energy value and battery balance energy value. When performing calculations, the target power duration calculation module mainly considers: battery control stage, operating condition control mode, actual output power of the battery stack, power response time, battery charge (discharge) cutoff energy, battery SOC and balance energy value.
[0092] Optionally, the target power optimization based on the SOC balance control stage and the operating condition control mode further includes: determining the initial value of the target power and the power change step size.
[0093] Specifically, the target power optimization judgment and control module needs to determine the initial value of the target power and the power change step size, that is, to calculate and calibrate the initial value of the target power and set the power change step size.
[0094] Optionally, the target power optimization based on the SOC balance control stage and the operating condition control mode further includes: limiting the target power extreme value, limiting the change gradient, and resetting the power change.
[0095] Specifically, in combination Figure 3 As shown, the fuel cell target power output module is used for the optimized target power limit output, including: current control mode output, output for other situations, power extreme value limit, gradient limitation, and power change reset processing. When the target power optimization judgment finds a new optimal target power, the target power output by the fuel cell target power output module uses the newly optimized power. If the optimal target power is not found, the target power output by the fuel cell target power output module is the target power of the previous step.
[0096] Optionally, the energy balance control method for the fuel cell further includes: estimating the power of vehicle accessories, the power of the vehicle, and the power of the fuel cell to estimate the energy fluctuation value of the fuel cell, and using the energy fluctuation value as the energy balance control target of the fuel cell.
[0097] Specifically, in combination Figure 2 and Figure 4 As shown, the inputs to the vehicle accessory power estimation module include, but are not limited to: compressor power, DC-DC power, and PTC power. The outputs of the vehicle accessory power estimation module include, but are not limited to: accessory power change status, total accessory power, and maximum accessory power (P). pmax ), which serves as one of the input signals (P0-P9) for the vehicle power balance model.
[0098] Combination Figure 2 and Figure 4 As shown, the inputs of the vehicle power estimation module include, but are not limited to: drive / regenerative power (D0-D9, above the 0 power line is positive drive power, below the 0 power line is negative regenerative power), maximum drive power, and maximum regenerative power. The outputs of the vehicle power estimation module include, but are not limited to: vehicle electric power at the battery end, vehicle power change status, and predicted maximum / minimum power, which serve as one of the input signals for the vehicle power balance model.
[0099] Combination Figure 2 and Figure 4 As shown, the inputs to the fuel cell power estimation module include, but are not limited to: total stack power, net stack power, and stack power capacity. The outputs of the fuel cell power estimation module include, but are not limited to: minimum power change gradient, maximum power change gradient, and net output power, serving as one of the input signals to the vehicle power balance model. Figure 4 In the diagram, the power of the fuel cell stack is represented by the curve F0-F9, and the actual power of the fuel cell stack is represented by F0. ’ -F9 ’ The curve (subject to the maximum power generation limit and the minimum power idling limit).
[0100] Combination Figure 2 and Figure 4 As shown, the inputs to the battery energy estimation module include, but are not limited to: battery control stage, battery SOC, and actual battery power; the outputs of the battery energy estimation module include, but are not limited to: estimated SOC / actual SOC, energy change direction, energy change state, and actual battery energy; the estimated value serves as the control target for battery energy balance, and considering the accuracy of the estimation, the actual battery SOC can be used to dynamically correct the battery energy estimation.
[0101] Combination Figure 2As shown, the inputs to the battery energy change estimation module include, but are not limited to: actual battery power, battery control stage, accessory power change status, total accessory power, maximum accessory power, vehicle power at the battery end, vehicle power change status, predicted maximum / minimum power, minimum power change gradient, maximum power change gradient, net output power, and maximum power capability; the outputs of the battery energy change estimation module include, but are not limited to: maximum accessory power, actual vehicle charging capability, minimum charge / discharge energy, maximum charge / discharge energy, predicted maximum / minimum vehicle power, minimum power change gradient, maximum power change gradient, and net output power.
[0102] Another embodiment of the present invention provides an energy balance control system for a fuel cell, including a computer-readable storage medium storing a computer program and a processor, wherein the computer program is read and executed by the processor to implement the above-described energy balance control method for the fuel cell.
[0103] Another embodiment of the present invention provides a vehicle including the above-described energy balance control system for a fuel cell.
[0104] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.
Claims
1. A method for energy balance control of a fuel cell, characterized in that, include: Acquire a preset input signal and determine the SOC balance control stage of the fuel cell based on the preset input signal. The preset input signal includes the current SOC value, the fast overcharge SOC threshold, the fast over-discharge SOC threshold, the throttle signal, and the vehicle power signal. The operating condition control mode is identified based on the preset input signal and the SOC balance control stage. The target power is optimized based on the SOC balance control stage and the operating condition control mode to determine the target power and target power output duration of the fuel cell. The step of optimizing the target power based on the SOC balance control stage and the operating condition control mode includes: Estimate the energy change value of the fuel cell based on the operating condition control mode; The remaining charging and discharging times of the fuel cell are estimated based on the energy change value, the SOC balance control stage, and the battery balance cutoff energy. Target power optimization is performed based on the operating condition control mode, the remaining charging time, the remaining discharging time, and the fuel cell's charge level. The step of optimizing the target power based on the operating condition control mode, the remaining charging time, the remaining discharging time, and the fuel cell's charge includes: The current target power is determined based on the operating condition control mode, the remaining charging time, the remaining discharging time, and the fuel cell's charge level. Estimate the target power response time based on the current target power; The current target power is corrected based on the target power response time to determine the target power and the target power output duration.
2. The energy balance control method for a fuel cell according to claim 1, characterized in that, The preset input signal includes the current SOC value, the rapid overcharge SOC threshold, and the rapid over-discharge SOC threshold. The step of determining the SOC balance control stage of the fuel cell based on the preset input signal includes: If the current SOC value is greater than the lower limit of the equilibrium SOC and less than the fast overcharge SOC threshold, then the fuel cell enters the battery fast overcharge control stage. When the fuel cell is in the fast overcharge control stage, if the current SOC value reaches the fast overcharge SOC threshold, the fuel cell enters the slow overcharge control stage. When the fuel cell is in the slow overcharge control stage, if the current SOC value reaches the upper limit of the balanced SOC, the fuel cell enters the fast over-discharge control stage. When the fuel cell is in the fast over-discharge control stage, if the current SOC value reaches the fast over-discharge SOC threshold, the fuel cell enters the slow over-discharge control stage.
3. The energy balance control method for a fuel cell according to claim 1, characterized in that, The preset input signal includes a throttle signal and a vehicle power signal. The step of identifying the operating condition control mode based on the preset input signal and the SOC balance control stage includes: The operating condition control mode is identified based on the throttle signal, the vehicle power signal, and the SOC balance control stage. The operating condition control mode includes idle mode, constant power mode, rapid power change mode, alternating power mode, and low power mode.
4. The energy balance control method for a fuel cell according to claim 1, characterized in that, The target power optimization based on the SOC balance control stage and the operating condition control mode further includes: determining the initial value of the target power and the power change step size.
5. The energy balance control method for a fuel cell according to claim 1, characterized in that, The target power optimization based on the SOC balance control stage and the operating condition control mode further includes: limiting the target power extreme value, limiting the change gradient, and resetting the power change.
6. The energy balance control method for a fuel cell according to claim 1, characterized in that, Also includes: The power of vehicle accessories, the power of the vehicle, and the power of the fuel cell are estimated to estimate the energy fluctuation value of the fuel cell, and the energy fluctuation value is used as the energy balance control target of the fuel cell.
7. An energy balance control system for a fuel cell, characterized in that, The method includes a computer-readable storage medium storing a computer program and a processor, the computer program being read and executed by the processor to implement the energy balance control method for a fuel cell as described in any one of claims 1 to 6.
8. A vehicle, characterized in that, Includes the energy balance control system for the fuel cell as described in claim 7.