Energy control method for hydrogen-electricity hybrid power system

Abstract

The invention relates to the technical field of new energy vehicles, and discloses a hydrogen-electricity hybrid power system energy control method, which comprises the following steps of: acquiring the required power of a whole vehicle and the SOC (State of Charge) of a power battery; if the SOC of the power battery is fully discharged, the required power of the whole vehicle is covered by the output power of the fuel cell system, and the power battery is charged at the same time; otherwise, the output power of the power battery covers; when the SOC of the power battery rises to be fully charged, the required power of the whole vehicle is covered by the power output by the power battery and the fuel cell system in a mixed mode, and meanwhile the current moment is marked as the completion of the full-charge and full-discharge cycle; in the process that the hybrid output power covers the required power of the whole vehicle, the total throughput of the output power of the power battery is calculated; when the total throughput of the output power of the power battery is greater than the total throughput of the battery with the minimum influence, covering by the output power of the power battery, and judging whether the SOC of the power battery is fully discharged or not in real time; according to the invention, the electric quantity calibration and voltage balance of the power battery can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicle technology, and specifically to an energy control method for a hydrogen-electric hybrid power system. Background Art

[0002] Hybrid new energy vehicles provide kinetic energy through hydrogen fuel cells and power batteries. Hydrogen fuel cells and power batteries are collectively called hydrogen-electric hybrid systems. At present, rule-based or follow-up energy control strategies are adopted for hydrogen-electric hybrid systems. Both strategies take maintaining a fixed SOC range of the power battery as the main control principle. The difference is that the rule-based energy control strategy takes the power battery SOC as the achievement condition, sets different fuel cell output powers, and the power battery uses the "more discharge and less supplement" principle to adjust the SOC range; the follow-up energy control strategy takes the working condition power demand as the achievement condition, sets different fuel cell output powers, and the power battery also uses the "more discharge and less supplement" principle to fine-tune the SOC range.

[0003] Regardless of whether it is a rule-based or follow-up hydrogen-electric hybrid system control strategy, the power battery SOC (state of charge, remaining capacity, %) is defined in a certain appropriate range. This range is mostly between 70% and 85%. In the long run, keeping the iron-lithium battery SOC in a fixed range will affect the power battery power calibration and voltage balancing. What's worse, poor voltage consistency may lead to EV restrictions or even thermal failure, causing serious damage to people and vehicles. Summary of the invention

[0004] The purpose of this application is to provide a hydrogen-electric hybrid system energy control method that can effectively improve the power battery charge calibration and voltage balance, and reduce the system EV limitation or even thermal failure caused by voltage consistency deviation due to the low activity of lithium iron phosphate.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A hydrogen-electric hybrid power system energy control method of the present invention includes obtaining the required power of the whole vehicle and the SOC of the power battery;

[0007] Determine whether the SOC of the power battery is fully discharged;

[0008] If the SOC of the power battery is fully discharged, the power demand of the whole vehicle is covered by the output power of the fuel cell system, and the power battery is charged at the same time, so that the SOC of the power battery increases; otherwise, the power demand of the whole vehicle is covered by the output power of the power battery;

[0009] Determine whether the SOC of the power battery has risen to full charge;

[0010] When the SOC of the power battery rises to full charge, the power demand of the vehicle is covered by the combined output of the power battery and the fuel cell system, and the current moment is marked as the completion of the full charge and discharge cycle;

[0011] When the combined output power of the power battery and fuel cell system covers the required power of the vehicle, calculate the total output power throughput of the power battery in real time since the most recent full charge and discharge cycle.

[0012] Compare the total throughput of the power battery output power with the total throughput of the battery with minimal impact based on power battery voltage balancing and consistency;

[0013] When the total output power throughput of the power battery is greater than the total battery throughput with minimal impact on power battery voltage balancing and consistency, the vehicle's required power is covered by the output power of the power battery, and it is determined in real time whether the SOC of the power battery is fully discharged.

[0014] Furthermore, when the SOC of the power battery rises to full charge, the method in which the power demand of the whole vehicle is covered by the power output of the power battery and the fuel cell system comprises:

[0015] Divide the SOC of the power battery into different intervals;

[0016] The corresponding fuel cell system output power is set according to the SOC range of the power battery;

[0017] According to the SOC range of the power battery, if the output power of the corresponding fuel cell system is greater than the power required by the whole vehicle, the part of the corresponding fuel cell system output power greater than the power required by the whole vehicle is used to charge the power battery; if the output power of the corresponding fuel cell system is less than or equal to the power required by the whole vehicle, the part of the corresponding fuel cell system output power less than the power required by the whole vehicle is supplemented by the output power of the power battery.

[0018] Furthermore, when the SOC of the power battery rises to full charge, the method in which the power demand of the whole vehicle is covered by the power output of the power battery and the fuel cell system comprises:

[0019] Divide the vehicle's required power into different intervals;

[0020] The corresponding fuel cell system output power is set according to the range of the vehicle's required power, and the set fuel cell system output power is greater than the minimum value of the corresponding range and less than the maximum value of the corresponding range;

[0021] According to the range of the actual power demand of the whole vehicle, if the corresponding fuel cell system output power is greater than the actual power demand of the whole vehicle, the part of the fuel cell system output power greater than the actual power demand of the whole vehicle is used to charge the power battery; if the corresponding fuel cell system output power is less than or equal to the actual power demand of the whole vehicle, the part of the fuel cell system output power less than the actual power demand of the whole vehicle is supplemented by the power battery output power.

[0022] Compared with the prior art, the beneficial effects of this application are:

[0023] In actual applications, when the SOC of the power battery is less than or equal to 5%, the power battery is judged to be fully discharged, and the power demand of the whole vehicle is provided by the output power of the fuel cell system. At the same time, the output power of the fuel cell system charges the power battery, so that the SOC of the power battery increases; when the SOC of the power battery is greater than or equal to 90%, the power battery is judged to be fully charged, and the power demand of the whole vehicle is covered by the power of the combined output of the power battery and the fuel cell system, and the current moment is marked as completing the full charge and discharge cycle; the throughput of the power battery affects the battery life, and adjusting the energy output mode according to the minimum throughput of the power battery can effectively avoid shortening the life of the power battery due to hybrid output; dynamically determine and adjust the "full charge and discharge" start time according to the output power of the power battery, and add "full charge and discharge" determination conditions and control methods on the basis of the original control method of providing kinetic energy with hybrid output, and dynamically determine; the method of the present application can effectively improve the power battery power calibration and voltage balance, and reduce the system ev limitation or even thermal failure caused by voltage consistency deviation due to the low activity of lithium iron phosphate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a flow chart of the method of this application. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0027] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show the layers related to the present invention rather than being drawn according to the number, shape and size of the layers in actual implementation. In actual implementation, the type, quantity and proportion of each layer may be changed arbitrarily, and the layer layout may also be more complicated.

[0028] In the following description, numerous details are discussed to provide a more thorough explanation of embodiments of the present invention; however, it is apparent to one skilled in the art that embodiments of the present invention may be practiced without these specific details.

[0029] See also Figure 1 , a hydrogen-electric hybrid power system energy control method, including obtaining the required power of the whole vehicle and the SOC of the power battery;

[0030] Determine whether the SOC of the power battery is fully discharged;

[0031] If the SOC of the power battery is fully discharged, the power demand of the whole vehicle is covered by the output power of the fuel cell system, and the power battery is charged at the same time, so that the SOC of the power battery increases; otherwise, the power demand of the whole vehicle is covered by the output power of the power battery;

[0032] Determine whether the SOC of the power battery has risen to full charge;

[0033] When the SOC of the power battery rises to full charge, the power demand of the vehicle is covered by the combined output of the power battery and the fuel cell system, and the current moment is marked as the completion of the full charge and discharge cycle;

[0034] When the combined output power of the power battery and fuel cell system covers the required power of the vehicle, calculate the total output power throughput of the power battery in real time since the most recent full charge and discharge cycle.

[0035] Compare the total throughput of the power battery output power with the total throughput of the battery with minimal impact based on power battery voltage balancing and consistency;

[0036] When the total output power throughput of the power battery is greater than the total battery throughput with minimal impact on power battery voltage balancing and consistency, the vehicle's required power is covered by the output power of the power battery, and it is determined in real time whether the SOC of the power battery is fully discharged.

[0037] In actual applications, when the SOC of the power battery is less than or equal to 5%, the power battery is judged to be fully discharged, and the power demand of the whole vehicle is provided by the output power of the fuel cell system. At the same time, the output power of the fuel cell system charges the power battery, so that the SOC of the power battery increases; when the SOC of the power battery is greater than or equal to 90%, the power battery is judged to be fully charged, and the power demand of the whole vehicle is covered by the power of the combined output of the power battery and the fuel cell system, and the current moment is marked as completing the full charge and discharge cycle; the throughput of the power battery affects the battery life, and adjusting the energy output mode according to the minimum throughput of the power battery can effectively avoid shortening the life of the power battery due to hybrid output; dynamically determine and adjust the "full charge and discharge" start time according to the output power of the power battery, and add "full charge and discharge" determination conditions and control methods on the basis of the original control method of providing kinetic energy with hybrid output, and dynamically determine; the method of the present application can effectively improve the power battery power calibration and voltage balance, and reduce the system ev limitation or even thermal failure caused by voltage consistency deviation due to the low activity of lithium iron phosphate.

[0038] When the SOC of the power battery rises to full charge, the method in which the power demand of the vehicle is covered by the power output of the power battery and the fuel cell system includes:

[0039] Divide the SOC of the power battery into different intervals;

[0040] The corresponding fuel cell system output power is set according to the SOC range of the power battery;

[0041] According to the SOC range of the power battery, if the output power of the corresponding fuel cell system is greater than the power required by the whole vehicle, the part of the corresponding fuel cell system output power greater than the power required by the whole vehicle is used to charge the power battery; if the output power of the corresponding fuel cell system is less than or equal to the power required by the whole vehicle, the part of the corresponding fuel cell system output power less than the power required by the whole vehicle is supplemented by the output power of the power battery.

[0042] For example, when the SOC of the power battery is in the range of (70%, 80%), the corresponding fuel cell system output power is 100kW. If the vehicle power demand is 120kW, the fuel cell system output power is less than 20kW of the vehicle power demand, which is supplemented by the power battery output power. If the vehicle power demand is 90kW, the fuel cell system output power is greater than 10kW of the vehicle power demand, which is used to charge the power battery.

[0043] When the SOC of the power battery rises to full charge, the method in which the power demand of the vehicle is covered by the power output of the power battery and the fuel cell system includes:

[0044] Divide the vehicle's required power into different intervals;

[0045] The corresponding fuel cell system output power is set according to the range of the vehicle's required power, and the set fuel cell system output power is greater than the minimum value of the corresponding range and less than the maximum value of the corresponding range;

[0046] According to the range of the actual power demand of the whole vehicle, if the corresponding fuel cell system output power is greater than the actual power demand of the whole vehicle, the part of the fuel cell system output power greater than the actual power demand of the whole vehicle is used to charge the power battery; if the corresponding fuel cell system output power is less than or equal to the actual power demand of the whole vehicle, the part of the fuel cell system output power less than the actual power demand of the whole vehicle is supplemented by the power battery output power.

[0047] For example, if the vehicle power demand is in the range of (180kW, 240kW], the corresponding fuel cell system output power is 210kW. If the vehicle power demand is actually 190kW, the fuel cell system output power is 20kW greater than the vehicle power demand, which is used to charge the power battery. If the vehicle power demand is actually 230kW, the fuel cell system output power is 10kW less than the vehicle power demand, which is supplemented by the power battery output power.

[0048] The control method of the present application can cover a variety of application scenarios such as fixed and mobile; and the control method of the present application can dynamically determine and adjust the "full charge and discharge" start time according to the power output of the power battery; on the basis of the original energy control strategy (including but not limited to rule-based, follow-up, and other control strategies for ambient temperature, road conditions, driving habits, etc.), a dynamic optimization process for the balance and consistency of lithium iron phosphate power batteries can be added to improve the accurate calculation of power and safety of use of power batteries in service.

[0049] In the above-mentioned embodiments, although the present invention has been described in conjunction with the specific embodiments of the present invention, many replacements, modifications and variations of these embodiments will be apparent to those of ordinary skill in the art based on the foregoing description. The embodiments of the present invention are intended to cover all such replacements, modifications and variations falling within the broad scope of the appended claims.

[0050] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for controlling energy of a hydrogen-electric hybrid power system, characterized in that: Including obtaining the required power of the vehicle and the SOC of the power battery; Determine whether the SOC of the power battery is fully discharged; If the SOC of the power battery is fully discharged, the power demand of the whole vehicle is covered by the output power of the fuel cell system, and the power battery is charged at the same time, so that the SOC of the power battery increases; otherwise, the power demand of the whole vehicle is covered by the output power of the power battery; Determine whether the SOC of the power battery has risen to full charge; When the SOC of the power battery rises to full charge, the power demand of the vehicle is covered by the combined output of the power battery and the fuel cell system, and the current moment is marked as the completion of the full charge and discharge cycle; When the combined output power of the power battery and fuel cell system covers the required power of the vehicle, calculate the total output power throughput of the power battery in real time since the most recent full charge and discharge cycle. Compare the total throughput of the power battery output power with the total throughput of the battery with minimal impact based on power battery voltage balancing and consistency; When the total output power throughput of the power battery is greater than the total battery throughput with minimal impact on power battery voltage balancing and consistency, the vehicle's required power is covered by the output power of the power battery, and it is determined in real time whether the SOC of the power battery is fully discharged.

2. The energy control method of a hydrogen-electric hybrid power system according to claim 1, characterized in that: When the SOC of the power battery rises to full charge, the method in which the power demand of the vehicle is covered by the power output of the power battery and the fuel cell system includes: Divide the SOC of the power battery into different intervals; The corresponding fuel cell system output power is set according to the SOC range of the power battery; According to the SOC range of the power battery, if the output power of the corresponding fuel cell system is greater than the power required by the whole vehicle, the part of the corresponding fuel cell system output power greater than the power required by the whole vehicle is used to charge the power battery; if the output power of the corresponding fuel cell system is less than or equal to the power required by the whole vehicle, the part of the corresponding fuel cell system output power less than the power required by the whole vehicle is supplemented by the output power of the power battery.

3. The energy control method of a hydrogen-electric hybrid power system according to claim 1, characterized in that: When the SOC of the power battery rises to full charge, the method in which the power demand of the vehicle is covered by the power output of the power battery and the fuel cell system includes: Divide the vehicle's required power into different intervals; The corresponding fuel cell system output power is set according to the range of the vehicle's required power, and the set fuel cell system output power is greater than the minimum value of the corresponding range and less than the maximum value of the corresponding range; According to the range of the actual power demand of the whole vehicle, if the corresponding fuel cell system output power is greater than the actual power demand of the whole vehicle, the part of the fuel cell system output power greater than the actual power demand of the whole vehicle is used to charge the power battery; if the corresponding fuel cell system output power is less than or equal to the actual power demand of the whole vehicle, the part of the fuel cell system output power less than the actual power demand of the whole vehicle is supplemented by the power battery output power.

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