Adaptive energy control method based on output characteristics of hybrid power generation system

Abstract

The application provides an adaptive energy control method based on output characteristics of a hybrid power generation system, which comprises the following steps: determining a power-efficiency output characteristic diagram according to total hydrogen input of an ammonia-hydrogen internal combustion engine and a hydrogen fuel cell; dividing the power-efficiency output characteristic diagram into a plurality of curve segments according to a first intersection of a straight line corresponding to a first efficiency threshold and the power-efficiency output characteristic diagram; determining a second efficiency threshold in a curve segment with an absolute value of a slope greater than a slope threshold, and determining a second intersection of a straight line corresponding to the second efficiency threshold and the corresponding curve segment; dividing output power of the power-efficiency output characteristic diagram into a plurality of power intervals according to the first intersection and the second intersection, and determining a working interval of the hybrid power generation system; and adjusting a hydrogen distribution ratio entering the hydrogen fuel cell so that the output power under the total hydrogen input is located in the working interval. The application realizes efficiency optimization of the hybrid power generation system with different output characteristics, and reduces battery capacity and residual power.

Description

Technical Field

[0001] This invention relates to the field of hybrid power generation system technology, and in particular to an adaptive energy control method based on the output characteristics of a hybrid power generation system. Background Technology

[0002] In practical engineering applications, loads often exhibit high fluctuation frequency and large fluctuation amplitude. Therefore, there are certain challenges in meeting the requirements of power devices that address these load characteristics: the power devices need to have high load output power, a wide range of variable output power, fast load response speed, easy-to-carry, store and transport fuel, and simple control methods.

[0003] Internal combustion engines are widely used due to their mature technology, rapid energy conversion, low cost, high output power, high waste heat quality, and abundant waste heat resources. Proton exchange membrane fuel cells have high application potential due to their high power generation efficiency and pollution-free emissions. Furthermore, compared to hydrogen and ammonia, they are easier to store and transport, and hydrogen production does not generate carbon emissions, resulting in good environmental performance. Batteries can effectively store and release electrical energy, playing a "peak shaving and valley filling" role in hybrid power generation systems under fluctuating load conditions, effectively improving system robustness and efficiency. Therefore, by constructing a hybrid power generation system equipped with a power battery—combining the advantages of the aforementioned components—and fully utilizing the waste heat resources of the components, the overall performance of the hybrid power generation system can be improved.

[0004] However, due to the different output characteristics of the internal combustion engine and fuel cell, this hybrid power generation system may exhibit "V"-shaped, "W"-shaped, or even other "wave-shaped" output efficiency-power characteristics. In real-world applications with frequent load fluctuations, traditional strategies for limiting distribution valve control can cause the system to operate within a lower efficiency range, leading to a decrease in overall system efficiency. Optimal component power distribution control strategies, on the other hand, can cause excessively rapid fluctuations in the control speed of the feed valve and distribution ratio valve, making it difficult to achieve optimal control. While strategies proposed for "V"-shaped and monotonic output characteristics can effectively optimize control in hybrid power generation systems with similar output characteristics, these control strategies are less adaptable to "W"-shaped and other "wave-shaped" characteristics. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes an adaptive energy control method based on the output characteristics of a hybrid power generation system. This method exhibits strong adaptability under different output characteristics, thereby optimizing the efficiency of hybrid power generation systems with varying output characteristics, reducing battery capacity and residual power, thus decreasing fuel costs and fixed investment costs, and improving the overall performance of the hybrid power generation system.

[0006] This invention provides an adaptive energy control method based on the output characteristics of a hybrid power generation system, comprising:

[0007] Based on the total amount of hydrogen fed into the ammonia-hydrogen internal combustion engine and the hydrogen fuel cell in the hybrid power generation system, the power-efficiency output characteristic diagram of the hybrid power generation system is determined.

[0008] Based on the first intersection point between the straight line corresponding to the first efficiency threshold and the power-efficiency output characteristic graph, the power-efficiency output characteristic graph is divided into multiple curve segments;

[0009] Within the curve segment where the absolute value of the slope is greater than the slope threshold, a second efficiency threshold is determined, and the second intersection point of the straight line corresponding to the second efficiency threshold and the corresponding curve segment is determined.

[0010] The output power of the power-efficiency output characteristic diagram is divided into multiple power ranges based on the first intersection point and the second intersection point, and the operating range of the hybrid power generation system is determined from the multiple power ranges.

[0011] By adjusting the hydrogen distribution ratio entering the hydrogen fuel cell, the output power of the hybrid power generation system is positioned within the operating range under the total hydrogen intake.

[0012] According to the present invention, an adaptive energy control method based on the output characteristics of a hybrid power generation system is provided. The power-efficiency output characteristic diagram includes one or more "V"-shaped curves. The output power of the power-efficiency output characteristic diagram is divided into multiple power intervals based on the first and second intersection points. The operating range of the hybrid power generation system is determined from these multiple power intervals, including:

[0013] Based on the second intersection point in each "V" curve and the first intersection point that is far from the second intersection point, the output power corresponding to each "V" curve is divided into a first power range, a second power range, and a third power range. The value in the first power range is less than the value in the second power range, and the value in the second power range is less than the value in the third power range.

[0014] The first power range and the third power range are defined as the operating range of the hybrid power generation system.

[0015] An adaptive energy control method based on the output characteristics of a hybrid power generation system, provided by the present invention, adjusts the hydrogen distribution ratio entering the hydrogen fuel cell so that the output power of the hybrid power generation system is within the operating range under the total hydrogen intake, comprising:

[0016] The load power is compared with each power range, and the target output power of the hybrid power generation system is determined based on the comparison results. The target output power is located within the operating range.

[0017] By adjusting the hydrogen distribution ratio entering the hydrogen fuel cell, the output power of the hybrid power generation system is made equal to the target output power.

[0018] An adaptive energy control method based on the output characteristics of a hybrid power generation system, provided by the present invention, compares the power of the load with various power ranges and determines the target output power of the hybrid power generation system based on the comparison results, including:

[0019] When the power of the load falls within the operating range, the target output power is equal to the power of the load;

[0020] When the power of the load is greater than the maximum value in the rightmost power range, the target output power is equal to the maximum value;

[0021] When the power of the load is less than the minimum value in the leftmost power range, the target output power is equal to the minimum value;

[0022] When the power of the load is within the second power range, the target output power is equal to the maximum value in the adjacent first output power range.

[0023] An adaptive energy control method based on the output characteristics of a hybrid power generation system, provided by the present invention, further includes:

[0024] Determine the difference between the power of the load and the target output power;

[0025] The battery does not operate when the power of the load is equal to the target output power;

[0026] When the power of the load is greater than the target output power, the difference in electrical energy is supplemented by the battery.

[0027] When the power of the load is less than the target output power, the excess electrical energy corresponding to the difference is stored in the battery.

[0028] An adaptive energy control method based on the output characteristics of a hybrid power generation system, provided by the present invention, further includes:

[0029] When the power of the load is greater than the target output power, the SOC of the battery is compared with a first preset threshold.

[0030] If the SOC of the battery is less than the first preset threshold, then reduce one or more of the first efficiency threshold, the second efficiency threshold, and the total amount of hydrogen entering the battery.

[0031] If the SOC of the battery is greater than or equal to the first preset threshold, then the battery will be used to replenish the electrical energy corresponding to the difference.

[0032] According to an adaptive energy control method based on the output characteristics of a hybrid power generation system provided by the present invention, if the SOC of the battery is less than a first preset threshold, one or more of the first efficiency threshold, the second efficiency threshold, and the total amount of hydrogen input are reduced, including:

[0033] If the SOC of the battery is less than the first preset threshold, then the second efficiency threshold is reduced to increase the range of the working range.

[0034] If the SOC of the battery does not increase after lowering the second efficiency threshold, then the first efficiency threshold is lowered to further increase the range of the operating range.

[0035] If the SOC of the battery does not increase after lowering the first efficiency threshold, then the total amount of hydrogen fed in is increased to expand the range of the operating range.

[0036] An adaptive energy control method based on the output characteristics of a hybrid power generation system, provided by the present invention, further includes:

[0037] When the power of the load is less than the target output power, the SOC of the battery is compared with a second preset threshold.

[0038] If the SOC of the battery is greater than the second preset threshold, the fuel cell hybrid power supply system stops working and the battery supplies power to the load.

[0039] If the SOC of the battery is less than or equal to the second preset threshold, the excess electrical energy corresponding to the difference is stored in the battery. The purpose of this invention is to solve the problem of complex output characteristics of hybrid power generation systems in practical engineering scenarios. It improves the power generation efficiency of hybrid power generation systems through an adaptive energy management strategy, while slightly increasing the peak charging and discharging power of the battery and reducing the battery's energy storage capacity and overall battery capacity.

[0040] The present invention achieves the above objectives through the following technical solutions:

[0041] To address the limitations of single-range efficiency control strategies in optimizing the performance of hybrid power generation systems with "V"-shaped output characteristics and their incompatibility with other "wave"-shaped output characteristics, this invention proposes an adaptive energy management strategy based on the output characteristics of hybrid power generation systems. This strategy involves controlling the total amount of hydrogen entering the internal combustion engine and fuel cell to a constant value, and adjusting the hydrogen distribution ratio entering the fuel cell to achieve power output within a certain range based on the hydrogen input. By limiting the output to a higher power generation efficiency range through the distribution ratio valve, this strategy effectively improves the power generation efficiency of the hybrid power generation system.

[0042] Furthermore, to address the limited efficiency and battery capacity optimization issues arising from single-range efficiency lower limit control during the regulation process, a new efficiency threshold is set for the smallest power range with the highest slope among the three power ranges, based on the existing range efficiency lower limit control strategy. This efficiency threshold is higher than the original efficiency lower limit. This allows the hybrid power generation system to improve efficiency by reducing a small amount of power output, thereby reducing battery capacity and residual charge after operation. Similarly, for "W"-shaped or even "wave"-shaped output characteristics, the slope of different power ranges can be observed based on a single efficiency range. A higher new efficiency threshold can be defined within the power range with the lowest slope, thereby effectively improving the efficiency of the hybrid power generation system and reducing battery capacity and residual charge.

[0043] The beneficial results of this invention are as follows:

[0044] The technical solution mentioned in this invention, compared with the traditional efficiency range control strategy of hybrid power generation systems, can make full use of the optimization space of the single efficiency range control strategy, thereby effectively improving the power generation efficiency and working efficiency of the hybrid power generation system, reducing the peak charging and discharging power of the battery and the required battery capacity, and reducing the total ammonia and ammonia storage tank capacity. It can effectively reduce the component cost of the hybrid power generation system and improve the overall efficiency of the hybrid power generation system. At the same time, this control strategy can be effectively extended to hybrid power generation systems with "V"-shaped, "W"-shaped and even "wave"-shaped output characteristics, with strong adaptability, providing a blueprint for the optimization control strategy of hybrid power generation systems with different output characteristics. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0046] Figure 1This is one of the flowcharts illustrating the adaptive energy control method based on the output characteristics of a hybrid power generation system provided by the present invention;

[0047] Figure 2 This is a schematic diagram of the structure of the hybrid power generation system in the adaptive energy control method based on the output characteristics of the hybrid power generation system provided by the present invention;

[0048] Figure 3 This is a schematic diagram of the output characteristics of the hybrid power generation system in the adaptive energy control method based on the output characteristics of the hybrid power generation system provided by the present invention;

[0049] Figure 4 This is a "V"-shaped power-efficiency output characteristic diagram of a hybrid power generation system in the adaptive energy control method based on the output characteristics of a hybrid power generation system provided by this invention;

[0050] Figure 5 This is a schematic diagram of the adaptive energy control of the "V"-shaped output characteristic system in the adaptive energy control method based on the output characteristics of the hybrid power generation system provided by the present invention;

[0051] Figure 6 This is a schematic diagram of the adaptive energy control method based on the output characteristics of a hybrid power generation system, which is extended to other characteristics in this invention.

[0052] Figure 7 This is the second adaptive energy control method based on the output characteristics of a hybrid power generation system provided by the present invention. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0054] The following is combined Figure 1 The present invention describes an adaptive energy control method based on the output characteristics of a hybrid power generation system, comprising:

[0055] Step 101: Determine the power-efficiency output characteristic diagram of the hybrid power generation system based on the total amount of hydrogen entering the ammonia-hydrogen internal combustion engine and the hydrogen fuel cell in the hybrid power generation system.

[0056] Step 102: Based on the first intersection point between the straight line corresponding to the first efficiency threshold and the power-efficiency output characteristic graph, divide the power-efficiency output characteristic graph into multiple curve segments;

[0057] Step 103: Determine the second efficiency threshold within the curve segment where the absolute value of the slope is greater than the slope threshold, and determine the second intersection point between the straight line corresponding to the second efficiency threshold and the corresponding curve segment;

[0058] Step 104: Divide the output power of the power-efficiency output characteristic diagram into multiple power intervals based on the first intersection point and the second intersection point, and determine the operating range of the hybrid power generation system from the multiple power intervals;

[0059] Step 105: By adjusting the hydrogen distribution ratio entering the hydrogen fuel cell, the output power of the hybrid power generation system is located within the operating range under the total hydrogen intake.

[0060] like Figure 2 As shown, the hybrid power generation system can be a hybrid power generation system consisting of an ammonia-hydrogen production system, an ammonia-hydrogen internal combustion engine, and a proton exchange membrane fuel cell. Its main components include an ammonia storage tank 1, a first multi-stream heat exchanger 2, a pressure reducing valve 3, a cooling water pump 4, a buffer tank 5, an ammonia regulating and distributing valve 6, a cylinder liner water pump 7, a second multi-stream heat exchanger 8, an internal combustion engine exhaust gas treatment device 9, a catalytic cracker 10, an air-cooled radiator 11, a burner 12, a hydrogen storage tank 13, a hydrogen storage tank inlet regulating valve 14, a separator 15, a power unit inlet hydrogen distribution regulating valve 16, an ammonia-hydrogen internal combustion engine 17, a hydrogen fuel cell 18, an internal combustion engine output current converter 19, a circuit merging device 20, a fuel cell output current converter 21, a battery current converter 22, a storage battery 23, and heavy-duty equipment 24.

[0061] The ammonia storage tank 1 stores liquid ammonia and serves as the energy source for the entire system. The first multi-stream heat exchanger 2 and the second multi-stream heat exchanger 8 are used to recover and utilize the cylinder liner water of the internal combustion engine and the cooling water of the fuel cell to preheat the low-temperature ammonia. They also utilize the heat from the hydrogen-nitrogen mixture and the exhaust gas of the internal combustion engine to reheat the ammonia. The pressure reducing valve 3 reduces the pressure of the vaporized ammonia entering the buffer tank, ensuring its safety. The cooling water pump 4 provides sufficient head for the fuel cell cooling water, ensuring smooth circulation of water in the pipeline. The buffer tank 5 stores the vaporized ammonia, reducing the pressure of ammonia directly entering the internal combustion engine and heat exchangers, better matching the ammonia input with the system output requirements. The ammonia regulating and distributing valve 6 distributes the ammonia, directing one path to the internal combustion engine and another to the catalytic converter. The cylinder liner water pump 7 provides sufficient head for the cylinder liner water of the internal combustion engine, ensuring smooth circulation of water in the pipeline. The internal combustion engine exhaust gas treatment device 9 removes nitrogen oxides generated in the engine exhaust gas. The catalytic converter 10 decomposes ammonia into hydrogen to fuel the fuel cell, internal combustion engine, and burner. It also includes a heat exchange device for the internal combustion engine exhaust to recover some of the exhaust heat. The air-cooled radiator 11 is a heat exchange device used to reduce the excess temperature of the internal combustion engine cylinder liner water and fuel cell cooling water to a set temperature. The burner 12 provides heat to the catalytic converter to ensure smooth catalytic processing. The hydrogen storage tank 13 stores hydrogen for system startup and to store excess hydrogen. The hydrogen inlet regulating valve 14 distributes some of the hydrogen required for combustion to the storage tank, and then to the burner. The separator 15 separates nitrogen, reducing the nitrogen allocated to the combustion and power units, thereby reducing nitrogen oxides and improving the system's energy conversion efficiency. The power unit hydrogen inlet regulating valve 16 distributes hydrogen to the internal combustion engine and fuel cell. The ammonia-hydrogen internal combustion engine 17 and the hydrogen fuel cell 1818 are the main power units of the system. The current generated is integrated through the circuit merging device 20 after passing through the internal combustion engine output current converter 19 and the fuel cell output current converter 21, to provide power to the heavy-duty equipment 24. When the power is insufficient or excessive, it is supplemented or absorbed by the battery 23 after passing through the battery current converter 22.

[0062] After the liquid ammonia is vaporized by heat exchange in the first multi-stream heat exchanger, it enters a buffer tank. Two pipelines exit the buffer tank, directly connecting to the internal combustion engine and the ammonia catalytic cracking unit, respectively. After catalytic cracking, the produced hydrogen is divided into two pipelines: one leads to a hydrogen storage tank and then to the burner, providing fuel for the burner; the other leads to the power unit. The pipeline to the power unit further branches into two: one leads to the internal combustion engine, providing fuel for the internal combustion engine; the other leads to the fuel cell, providing fuel for the fuel cell. The amount of ammonia fed into the internal combustion engine is proportional to the amount of hydrogen fed into the engine. The fuel required for burner reheating is supplied in real-time according to system demand.

[0063] like Figure 3 As shown in the test, it was found that under the same total hydrogen intake, as the hydrogen allocation ratio of the fuel cell increases, the system output power decreases, and one hydrogen allocation ratio corresponds to one system output power. With the increase of the allocation ratio, the output of the fuel cell in the hybrid power generation system increases, the output of the internal combustion engine decreases, and the total output of the hybrid system decreases. When the total hydrogen intake is large, within a certain range, as the allocation ratio increases, the output of the hybrid power generation system increases because the internal combustion engine may experience full load.

[0064] like Figure 4 As shown in the diagram, tests revealed that, under a constant total hydrogen intake, the output efficiency versus output power of the hybrid system exhibits a "V"-shaped curve. At lower output power, the hybrid power generation system's output is primarily driven by the fuel cell. As output power increases, the proportion of output from the more efficient fuel cell decreases, while the proportion from the internal combustion engine increases, leading to a decrease in the hybrid power generation system's output efficiency. Conversely, at higher output power, the hybrid power generation system's output is dominated by the internal combustion engine. The output efficiency of the internal combustion engine increases with increasing output power, and consequently, the output efficiency of the hybrid power generation system also increases with increasing output power. Therefore, within a certain range, the hybrid system's output efficiency decreases with increasing output power; however, when the output power exceeds this range, the output efficiency increases with increasing output power, resulting in a "V"-shaped curve for the hybrid system's output efficiency versus output power relationship.

[0065] The output characteristics of internal combustion engines show that the output efficiency does not increase monotonically with the increase of output power; it may also fluctuate. Therefore, the output power-output efficiency characteristic curve of a hybrid power generation system exhibits a "V"-shaped, "W"-shaped, or even "wave"-shaped relationship.

[0066] like Figure 5As shown, a lower limit for the power generation efficiency of the hybrid power generation system is set before it starts operating, and this lower limit is named the first efficiency threshold. At the same time, an iso-efficiency line of the first efficiency threshold is plotted on the power-efficiency output characteristic diagram corresponding to the set total hydrogen input. This iso-efficiency line divides the output characteristic curve into three power intervals according to the power magnitude: the first power interval, the second power interval, and the third power interval.

[0067] Based on this, a slope threshold is set. The absolute value of the slope at the first intersection point of the isoefficiency line of the first efficiency threshold and the output characteristic curve is used as the slope threshold. The slope within the first power range is compared with the slope threshold at the upper intersection point of the first power range, and the slope within the third power range is compared with the slope threshold at the upper intersection point of the third power range. A new efficiency threshold is defined within the power range that meets the slope threshold, and this efficiency threshold is named the second efficiency threshold. This reduces the variation in the power output range in exchange for improved power generation efficiency. The intersection point of the isoefficiency line of the second efficiency threshold and the power range that meets the slope threshold is used as the second intersection point. The operating range of the hybrid power generation system is determined based on the first and second intersection points. By adjusting the hydrogen distribution ratio entering the hydrogen fuel cell, the output power of the hybrid power generation system under a certain total hydrogen intake is kept within the operating range.

[0068] This embodiment, through a range-based efficiency lower limit control strategy, sets a new efficiency threshold for power ranges with higher slopes among multiple power ranges. This efficiency threshold is higher than the original efficiency lower limit. This allows the hybrid power generation system to improve efficiency by reducing power output, thereby reducing battery capacity and residual charge after operation. Similarly, for "W"-shaped or even "wave"-shaped output characteristics, the slope of different power ranges can be observed based on a single efficiency range. A higher new efficiency threshold can be defined within the power range with a lower slope to achieve adaptive energy control. This effectively improves the efficiency of the hybrid power generation system, reduces battery capacity and residual charge, thereby reducing fuel costs and fixed investment costs, and improving the overall performance of the hybrid power generation system.

[0069] Based on the above embodiments, the power-efficiency output characteristic diagram in this embodiment includes one or more "V"-shaped curves. The output power of the power-efficiency output characteristic diagram is divided into multiple power ranges based on the first and second intersection points. The operating range of the hybrid power generation system is determined from these multiple power ranges, including:

[0070] Based on the second intersection point in each "V" curve and the first intersection point that is far from the second intersection point, the output power corresponding to each "V" curve is divided into a first power range, a second power range, and a third power range. The value in the first power range is less than the value in the second power range, and the value in the second power range is less than the value in the third power range.

[0071] The first power range and the third power range are defined as the operating range of the hybrid power generation system.

[0072] by Figure 5 For example, since the absolute value of the slope of the curve in the first power range is greater than the slope threshold, a second efficiency threshold is defined in the first power range. This efficiency threshold line intersects the output characteristic curve at point 1' in the first power range, and the minimum output power point in the first power range is point 1. Simultaneously, the minimum output power point in the third power range is set at point 2, which is the intersection of the first efficiency threshold and the third power range, and the maximum output power point in this power range is point 2'. Therefore, based on points 1' and 2, the output power corresponding to the "V"-shaped curve is divided into a first power range between point 1 and point 1', a second power range between point 1' and point 2, and a third power range between point 2 and point 2'. The operating range consists of the first and third power ranges. The hybrid power generation system achieves power output within a certain range based on the total amount of hydrogen entering the fuel cell by adjusting the hydrogen distribution ratio.

[0073] like Figure 6As shown, when the output characteristics of an internal combustion engine change, the system's output characteristics no longer exhibit a "V" shape, but may also show a "W" shape or even a "wave" shape. Taking the "W" shaped output characteristic curve as an example, the specific implementation method of energy control is as follows: First, set a lower efficiency limit and name it the first efficiency threshold. Draw an iso-efficiency line intersecting the output characteristic curve at this efficiency threshold. Simultaneously, the output characteristic curve has an extreme point located at the efficiency threshold. Then, draw an iso-power line based on the intersection point and the extreme point of the characteristic curve. Divide the power range into six intervals according to the output power, from smallest to largest: the first power interval, the second power interval, the third power interval, the fourth power interval, the fifth power interval, and the sixth power interval. Next, based on the monotonicity of each power interval, set different positive and negative slope thresholds. When the slope of each interval is higher than the slope threshold, these power intervals are considered to meet the conditions for setting a second efficiency threshold. Set the second efficiency threshold in these power intervals so that the output of the hybrid power generation system is higher than this efficiency threshold, thereby determining the power output ranges with different output characteristics. In the illustrated "W"-shaped characteristic curves, the slopes of the output characteristic curves in the first and fourth power ranges meet the slope threshold. Therefore, a higher efficiency threshold is defined for these ranges and named the second efficiency threshold. The output range of the hybrid power generation system in the first and fourth power ranges is above the higher efficiency threshold, while the output range in the remaining ranges is above the original first efficiency threshold. Further control details are as follows... Figure 5 The content remains consistent.

[0074] Based on the above embodiments, this embodiment adjusts the hydrogen distribution ratio entering the hydrogen fuel cell so that the output power of the hybrid power generation system is within the operating range under the total hydrogen intake, including:

[0075] The load power is compared with each power range, and the target output power of the hybrid power generation system is determined based on the comparison results. The target output power is located within the operating range.

[0076] By adjusting the hydrogen distribution ratio entering the hydrogen fuel cell, the output power of the hybrid power generation system is made equal to the target output power.

[0077] by Figure 5For example, when the load power is less than the output power corresponding to point 1, the system output power is output according to point 1, and the excess power is stored in the battery; when the load power is between point 1 and point 1', the system output power is equal to the load output, and the battery does not work; when the load power is between point 1' and point 2, the system output power is output according to point 1', and the battery supplements the insufficient power; when the load power is between point 2 and point 2', the system output power is equal to the load output, and the battery does not work; when the load is greater than point 2', the system output power is output according to point 2', and the battery supplements the insufficient power.

[0078] Based on the above embodiments, this embodiment compares the load power with each power range, and determines the target output power of the hybrid power generation system based on the comparison results, including:

[0079] When the power of the load falls within the operating range, the target output power is equal to the power of the load;

[0080] When the power of the load is greater than the maximum value in the rightmost power range, the target output power is equal to the maximum value;

[0081] When the power of the load is less than the minimum value in the leftmost power range, the target output power is equal to the minimum value;

[0082] When the power of the load is within the second power range, the target output power is equal to the maximum value in the adjacent first output power range.

[0083] Based on the above embodiments, this embodiment also includes:

[0084] Determine the difference between the power of the load and the target output power;

[0085] The battery does not operate when the power of the load is equal to the target output power;

[0086] When the power of the load is greater than the target output power, the difference in electrical energy is supplemented by the battery.

[0087] When the power of the load is less than the target output power, the excess electrical energy corresponding to the difference is stored in the battery.

[0088] Based on the above embodiments, this embodiment also includes:

[0089] When the power of the load is greater than the target output power, the SOC of the battery is compared with a first preset threshold.

[0090] If the SOC of the battery is less than the first preset threshold, then reduce one or more of the first efficiency threshold, the second efficiency threshold, and the total amount of hydrogen entering the battery.

[0091] If the SOC of the battery is greater than or equal to the first preset threshold, then the battery will be used to replenish the electrical energy corresponding to the difference.

[0092] Based on the above embodiments, in this embodiment, if the SOC of the battery is less than the first preset threshold, then one or more of the first efficiency threshold, the second efficiency threshold, and the total amount of hydrogen entering the battery are reduced, including:

[0093] If the SOC of the battery is less than the first preset threshold, then the second efficiency threshold is reduced to increase the range of the working range.

[0094] If the SOC of the battery does not increase after lowering the second efficiency threshold, then the first efficiency threshold is lowered to further increase the range of the operating range.

[0095] If the SOC of the battery does not increase after lowering the first efficiency threshold, then the total amount of hydrogen fed in is increased to expand the range of the operating range.

[0096] Based on the above embodiments, this embodiment also includes:

[0097] When the power of the load is less than the target output power, the SOC of the battery is compared with a second preset threshold.

[0098] If the SOC of the battery is greater than the second preset threshold, the fuel cell hybrid power supply system stops working and the battery supplies power to the load.

[0099] If the SOC of the battery is less than or equal to the second preset threshold, the excess electrical energy corresponding to the difference is stored in the battery.

[0100] like Figure 7 As shown, the specific control process of the dual-efficiency threshold control strategy is as follows: Before the hybrid power generation system starts operating, the power generation efficiency threshold of the hybrid power generation system is set, and a certain total amount of hydrogen input is set during operation. Based on the output characteristic diagram of this total hydrogen input and the power output point corresponding to the lower efficiency limit, several power ranges of the system are determined, and combined with... Figure 5 and Figure 6 The aforementioned content defines several power ranges, and simultaneously determines the operating range of the hybrid power generation system based on the output efficiency-power characteristics and the defined first and second efficiency thresholds. The hybrid power generation system achieves power output within a certain range based on the total amount of hydrogen entering the fuel cell by adjusting the hydrogen distribution ratio.

[0101] When the load power falls within the operating range, the system output equals the load power, and the battery does not work.

[0102] When the load power exceeds the maximum operating range, the system outputs according to the maximum output point. At this time, the SOC value of the battery is judged: if the battery SOC is lower than the set threshold, the second efficiency threshold set by the system is lowered to increase the system output range; if modifying the second efficiency threshold still fails to increase the SOC value, the lower limit of the first efficiency threshold is modified to further increase the system output range; if neither of these methods can increase the threshold, the total amount of hydrogen fed in is modified to increase the system output range; if the battery SOC is not lower than the set threshold, the battery is supplemented with insufficient power.

[0103] When the load power is less than the minimum operating range, the SOC value of the battery is judged: if the battery SOC exceeds the set threshold, the hybrid system stops working and only the battery outputs power; if the battery SOC does not exceed the set threshold, the system outputs power according to the minimum output power, and the battery stores excess power.

[0104] When the load power is between two adjacent operating ranges, the SOC value of the battery is judged: if the battery SOC is lower than the set threshold, the operation is carried out in sequence according to modifying the second efficiency threshold, the first efficiency threshold, and increasing the total amount of hydrogen intake to improve the output range of the system; if the battery SOC is not lower than the set threshold, the system outputs according to the maximum output power of the adjacent smaller operating range, and the battery supplements the insufficient power.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive energy control method based on the output characteristics of a hybrid power generation system, characterized in that, include: Based on the total amount of hydrogen fed into the ammonia-hydrogen internal combustion engine and the hydrogen fuel cell in the hybrid power generation system, the power-efficiency output characteristic diagram of the hybrid power generation system is determined. Based on the first intersection point between the straight line corresponding to the first efficiency threshold and the power-efficiency output characteristic diagram, the power-efficiency output characteristic diagram is divided into multiple curve segments, where the first efficiency threshold is the set lower limit of the power generation efficiency of the hybrid power generation system. Within the curve segment where the absolute value of the slope is greater than the slope threshold, a second efficiency threshold is determined, and the second intersection point of the straight line corresponding to the second efficiency threshold and the corresponding curve segment is determined. The output power of the power-efficiency output characteristic diagram is divided into multiple power ranges based on the first intersection point and the second intersection point, and the operating range of the hybrid power generation system is determined from the multiple power ranges. By adjusting the hydrogen distribution ratio entering the hydrogen fuel cell, the output power of the hybrid power generation system is located within the operating range under the total amount of hydrogen input; The power-efficiency output characteristic diagram includes one or more "V"-shaped curves. Based on the first and second intersection points, the output power of the power-efficiency output characteristic diagram is divided into multiple power ranges. The operating range of the hybrid power generation system is determined from these multiple power ranges, including: Based on the second intersection point in each "V" curve and the first intersection point that is far from the second intersection point, the output power corresponding to each "V" curve is divided into a first power range, a second power range, and a third power range. The value in the first power range is less than the value in the second power range, and the value in the second power range is less than the value in the third power range. The first power range and the third power range are defined as the operating range of the hybrid power generation system.

2. The adaptive energy control method based on the output characteristics of a hybrid power generation system according to claim 1, characterized in that, By adjusting the hydrogen distribution ratio entering the hydrogen fuel cell, the output power of the hybrid power generation system is located within the operating range under the total hydrogen intake, including: The load power is compared with each power range, and the target output power of the hybrid power generation system is determined based on the comparison results. The target output power is located within the operating range. By adjusting the hydrogen distribution ratio entering the hydrogen fuel cell, the output power of the hybrid power generation system is made equal to the target output power.

3. The adaptive energy control method based on the output characteristics of a hybrid power generation system according to claim 2, characterized in that, The load power is compared with each power range, and the target output power of the hybrid power generation system is determined based on the comparison results, including: When the power of the load falls within the operating range, the target output power is equal to the power of the load; When the power of the load is greater than the maximum value in the rightmost power range, the target output power is equal to the maximum value; When the power of the load is less than the minimum value in the leftmost power range, the target output power is equal to the minimum value; When the power of the load is within the second power range, the target output power is equal to the maximum value in the adjacent first power range.

4. The adaptive energy control method based on the output characteristics of a hybrid power generation system according to claim 3, characterized in that, Also includes: Determine the difference between the power of the load and the target output power; The battery does not operate when the power of the load is equal to the target output power; When the power of the load is greater than the target output power, the difference in electrical energy is supplemented by the battery. When the power of the load is less than the target output power, the excess electrical energy corresponding to the difference is stored in the battery.

5. The adaptive energy control method based on the output characteristics of a hybrid power generation system according to claim 4, characterized in that, Also includes: When the power of the load is greater than the target output power, the SOC of the battery is compared with a first preset threshold. If the SOC of the battery is less than the first preset threshold, then reduce one or more of the first efficiency threshold, the second efficiency threshold, and the total amount of hydrogen entering the battery. If the SOC of the battery is greater than or equal to the first preset threshold, then the battery will be used to replenish the electrical energy corresponding to the difference.

6. The adaptive energy control method based on the output characteristics of a hybrid power generation system according to claim 5, characterized in that, If the SOC of the battery is less than the first preset threshold, then one or more of the first efficiency threshold, the second efficiency threshold, and the total amount of hydrogen intake are reduced, including: If the SOC of the battery is less than the first preset threshold, then the second efficiency threshold is reduced to increase the range of the working range. If the SOC of the battery does not increase after lowering the second efficiency threshold, then the first efficiency threshold is lowered to further increase the range of the operating range. If the SOC of the battery does not increase after lowering the first efficiency threshold, then the total amount of hydrogen fed in is increased to expand the range of the operating range.

7. The adaptive energy control method based on the output characteristics of a hybrid power generation system according to claim 4, characterized in that, Also includes: When the power of the load is less than the target output power, the SOC of the battery is compared with a second preset threshold. If the SOC of the battery is greater than the second preset threshold, the fuel cell hybrid power supply system stops working and the battery supplies power to the load. If the SOC of the battery is less than or equal to the second preset threshold, the excess electrical energy corresponding to the difference is stored in the battery.

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