CN116613724A - Multi-stack PEMFC power generation system start-stop coordination control method considering life optimization - Google Patents
Multi-stack PEMFC power generation system start-stop coordination control method considering life optimization Download PDFInfo
- Publication number
- CN116613724A CN116613724A CN202310471301.1A CN202310471301A CN116613724A CN 116613724 A CN116613724 A CN 116613724A CN 202310471301 A CN202310471301 A CN 202310471301A CN 116613724 A CN116613724 A CN 116613724A
- Authority
- CN
- China
- Prior art keywords
- pemfc
- stack
- efficiency
- power generation
- generation system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000010248 power generation Methods 0.000 title claims abstract description 72
- 238000000034 method Methods 0.000 title claims abstract description 51
- 238000005457 optimization Methods 0.000 title claims abstract description 14
- 238000011156 evaluation Methods 0.000 claims abstract description 14
- 238000012423 maintenance Methods 0.000 claims abstract description 9
- 239000000446 fuel Substances 0.000 claims description 32
- 229910052739 hydrogen Inorganic materials 0.000 claims description 26
- 239000001257 hydrogen Substances 0.000 claims description 26
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 22
- 238000006243 chemical reaction Methods 0.000 claims description 13
- 239000000126 substance Substances 0.000 claims description 11
- 238000012360 testing method Methods 0.000 claims description 8
- 230000002035 prolonged effect Effects 0.000 claims description 6
- -1 hydrogen Chemical class 0.000 claims 1
- 150000002431 hydrogen Chemical class 0.000 description 5
- 239000012528 membrane Substances 0.000 description 5
- 238000011161 development Methods 0.000 description 3
- 230000018109 developmental process Effects 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 241000282414 Homo sapiens Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 239000002803 fossil fuel Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
- H01M8/249—Grouping of fuel cells, e.g. stacking of fuel cells comprising two or more groupings of fuel cells, e.g. modular assemblies
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04992—Processes for controlling fuel cells or fuel cell systems characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/109—Scheduling or re-scheduling the operation of the DC sources in a particular order, e.g. connecting or disconnecting the sources in sequential, alternating or in subsets, to meet a given demand
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/12—Parallel operation of dc generators with converters, e.g. with mercury-arc rectifier
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/30—The power source being a fuel cell
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Power Engineering (AREA)
- Artificial Intelligence (AREA)
- Automation & Control Theory (AREA)
- Computing Systems (AREA)
- Evolutionary Computation (AREA)
- Fuzzy Systems (AREA)
- Medical Informatics (AREA)
- Software Systems (AREA)
- Theoretical Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Fuel Cell (AREA)
Abstract
The invention relates to a start-stop coordination control method of a multi-stack PEMFC power generation system considering life optimization, which considers the problem of reducing the start-stop life optimization of the multi-stack PEMFC power generation system on the basis of meeting the overall system efficiency requirement, determines the high-efficiency range of the system according to the use scene, reasonably starts and stops each single-stack PEMFC subsystem by taking the lowest efficiency value of the range interval as an evaluation index, and greatly reduces the start-stop times of each electric stack of the system while ensuring the stable operation of the multi-stack PEMFC power generation system with higher efficiency, thereby improving the service life of the system and reducing the maintenance cost. According to the method, the number of the single-stack PEMFC subsystems can be automatically judged by taking a given lowest system efficiency value as an evaluation index according to the load change condition; under different use scenes, the minimum value of the system efficiency can be flexibly changed according to scene load characteristics, and the balance between the overall efficiency and the service life optimization of the multi-stack PEMFC power generation system is sought.
Description
Technical Field
The invention relates to the technical field of fuel cells, in particular to a start-stop coordination control method of a multi-stack PEMFC power generation system considering life optimization.
Background
Energy is an important support for social development and national economy, and along with the increasing exhaustion of non-renewable energy sources such as fossil fuels, the global energy crisis and environmental problems are urgently needed to be solved. The hydrogen energy is a new energy source which is high-efficient, clean, safe and sustainable, and is a main development direction for solving the energy problem in the future of human beings. The fuel cell is a chemical device for directly converting chemical energy of fuel such as hydrogen into electric energy, has the advantages of high energy conversion efficiency, high safety, environmental protection, low noise and the like, is widely applied to the fields of distributed power generation, traffic vehicles, mobile equipment and the like, and is a power generation device with huge development potential.
The proton exchange membrane fuel cell (Proton Exchange Membrane Fuel Cell, PEMFC) has the advantages of quick start at room temperature, no electrolyte loss and the like, and is very suitable for being used as a mobile power supply and a distributed power supply. However, because the single power level of the proton exchange membrane fuel cell is not high at present, the real-time power requirement of a high-power use scene is difficult to meet; meanwhile, the defects of environmental influence, insufficient durability, relatively high cost and the like of the working performance caused by the complex integral structure and the strict material requirement cannot be ignored, so that the problems of power grade and durability of the proton exchange membrane fuel cell must be concerned when the proton exchange membrane fuel cell is adopted as a power supply.
When the single-stack PEMFC system is operated in a parallel topology structure in a multi-stack mode, the power level and the overall efficiency of the single-stack PEMFC system can be greatly improved, redundancy of the PEMFC power generation system is effectively increased, and the stability and the reliability of the system in operation are improved. The conventional power allocation strategies commonly used mainly comprise an average allocation strategy and a step-by-step allocation strategy. The average distribution strategy, that is, all pile systems are started simultaneously, when the systems are in a low-power interval, the cost is higher, the efficiency is lower, the lowest output power of the strategy is the sum of the lowest output powers of all subsystems, and the defect aiming at the low-power interval is obvious; the step-by-step distribution strategy can realize the output of a wider power range of the system, and the system efficiency can be obviously improved when the power is output, but the efficiency is highest only when the first electric pile is operated, and the overall system efficiency is drastically reduced along with the operation of more electric piles.
Disclosure of Invention
In order to solve the problems, the invention provides a start-stop coordination control method of a multi-stack PEMFC power generation system considering life optimization, which is characterized in that a high-efficiency range of the system is determined according to a use scene, and each single-stack PEMFC system is reasonably started and stopped by taking the lowest efficiency value of a range interval as an evaluation index through a simple control method, so that the start-stop times of each stack of the system are greatly reduced while the stable operation of the multi-stack PEMFC power generation system with higher efficiency is ensured, the service life of the system is prolonged, and the maintenance cost is reduced.
The technical scheme adopted by the invention is as follows: a start-stop coordination control method of a multi-stack PEMFC power generation system considering life optimization is characterized by comprising the following steps: the method comprises the following steps:
s10: establishing a topological structure of a multi-stack PEMFC power generation system formed by connecting a plurality of identical single-stack PEMFC systems in parallel;
s20: calculating the efficiency of a single-stack PEMFC system, and obtaining the change relation of the efficiency of the single-stack PEMFC system along with the output power; drawing efficiency change curves with output power when different numbers Shan Dui PEMFC subsystems are started according to actual test data;
s30: according to the high-efficiency range of the system, through a start-stop coordination control method of the multi-stack PEMFC power generation system, each single-stack PEMFC subsystem is reasonably started and stopped by taking the lowest efficiency value of the range interval as an evaluation index, the start-stop times of each stack of the system are greatly reduced while the stable operation of the multi-stack PEMFC power generation system with higher efficiency is ensured, the service life of the system is prolonged, and the maintenance cost is reduced.
Preferably, in step S10, the established topology structure of the multi-stack PEMFC power generation system is formed by adopting a parallel topology form for a plurality of single-stack PEMFC systems, so as to increase redundancy of the PEMFC systems and improve power level and stability of the systems; each single-pile PEMFC system comprises a PEMFC pile and a DC/DC converter, each PEMFC pile is cascaded with one DC/DC converter and is connected with a direct current bus, and the multi-pile PEMFC power generation system under the topological structure can realize independent operation and control of the single-pile PEMFC subsystem and can also be put into operation while keeping multiple piles one by one or simultaneously.
Preferably, in step S30, the PEMFC power generation system efficiency is mainly composed of fuel utilization, stack conversion efficiency, and system electrical efficiency, and the single-stack PEMFC system efficiency η fc_sys The calculation formula is as follows:
η fc_sys ＝η fuel ·η conv ·η elec
wherein: η (eta) fuel Is the fuel utilization rate eta conv Is the conversion efficiency eta of the galvanic pile elec For system electrical efficiency.
Preferably, in step S30, the fuel utilization η fuel For the ratio between the hydrogen consumed by the PEMFC and the hydrogen supplied to the PEMFC, the hydrogen of the multi-stack PEMFC power generation system is recycled, and the calculation formula is as follows:
wherein: e (E) H2_consummed To consume the chemical energy of hydrogen, E H2_in For entering the chemical energy of hydrogen, M H2_consummed For the mass, M, of hydrogen consumed H2_in Is the mass of hydrogen gas that enters.
Preferably, in step S30, the pile conversion efficiency η conv Generating electric energy E for PEMFC stack Chemical energy E with consumed Hydrogen H2_consummed The ratio between the output voltage V of the PEMFC and the output voltage V of the PEMFC C And heat of reaction E heat The calculation formula is as follows:
preferably, in step S30, the system electrical efficiency η elec Output energy E for PEMFC net And generating energy E stack The ratio between the electric efficiency E of the PEMFC power generation system of auxiliary equipment such as an air compressor and the like aux /E stack And efficiency eta of unidirectional DC/DC converter DC/DC The composition and the calculation formula are as follows:
preferably, in step S30, according to actual test data, a curve of efficiency versus output power when the different number of single-stack PEMFC systems are started is drawn: according to the actual operation characteristics of the system, the output power and the overall system efficiency of different numbers of Shan Dui PEMFC subsystems under the actual working condition are acquired and calculated, and the characteristic curves of the overall system efficiency of different numbers Shan Dui PEMFC subsystems along with the change of the output power are drawn.
Preferably, in step S40, a high efficiency range of the system is determined according to a usage scenario, and by using a start-stop coordination control method of the multi-stack PEMFC power generation system, each single-stack PEMFC subsystem is reasonably started and stopped by taking the lowest efficiency value of the range interval as an evaluation index, so that the start-stop times of each stack of the system are greatly reduced while the stable operation of the multi-stack PEMFC power generation system with higher efficiency is ensured: determining a high efficiency range of the system according to a characteristic curve of the overall system efficiency changing along with the output power and according to a use scene, judging whether to start or stop a single-stack PEMFC subsystem to maintain the overall system efficiency value within a given high efficiency range of the system, namely determining the number of stacks running in real time;
when the overall efficiency of the k single-stack PEMFC subsystems is larger than or equal to a given system efficiency minimum value, a new electric stack is not required to be put in; when the load power is gradually increased and the overall system efficiency is reduced to a given minimum system efficiency value, the (k+1) th single-stack PEMFC subsystem is required to be input so as to improve the overall system efficiency; the power is the (k+1) th single-stack PEMFC subsystem start turning power P (k)h,max When the load power P load Less than P (k)h,max When the load power is shared by the top k single-stack PEMFC subsystems, the load power is shared by the top k single-stack PEMFC subsystems FCk Is of the formula:
P load ＝P FC1 +P FC2 +…+P FCk
P FC1 ＝P FC2 ＝…＝P FCk
when the overall efficiency of the k single-stack PEMFC subsystems is greater than or equal to a given system efficiency minimum value, the running electric stack does not need to be withdrawn; when the load power is gradually reduced and the overall system efficiency is reduced to a given minimum system efficiency value, the kth single-stack PEMFC subsystem needs to be withdrawn so as to improve the overall system efficiency; the power is the turning power P of the kth single-stack PEMFC subsystem (k)h,min When the load power P load Greater than P (k)h,min When the load power is shared by the first k single-stack PEMFC subsystems;
and the multi-stack PEMFC power generation system automatically judges the number of the start-stop single-stack PEMFC subsystems according to the load change condition in real time by taking a given minimum system efficiency value as an evaluation index.
The beneficial effects obtained by the invention are as follows: the invention provides a start-stop coordination control method of a multi-stack PEMFC power generation system, which considers the problem of reducing the start-stop life optimization of the multi-stack PEMFC power generation system on the basis of meeting the overall system efficiency requirement, and provides the start-stop coordination control method of the multi-stack PEMFC power generation system, which considers the life optimization: according to the high-efficiency range of the system, through a start-stop coordination control method of the multi-stack PEMFC power generation system, each single-stack PEMFC subsystem is reasonably started and stopped by taking the lowest efficiency value of the range interval as an evaluation index, the start-stop times of each stack of the system are greatly reduced while the stable operation of the multi-stack PEMFC power generation system with higher efficiency is ensured, the service life of the system is prolonged, and the maintenance cost is reduced.
According to the invention, the power level of the PEMFC is effectively improved, a single PEMFC stack is cascaded with a DC/DC converter to be connected with a DC bus, and the multi-stack PEMFC power generation system under the topological structure can realize independent operation and control of the single-stack PEMFC subsystem and can also be put into operation while keeping multiple stacks one by one or simultaneously.
According to the invention, the multi-stack PEMFC power generation system automatically judges the number of the start-stop single-stack PEMFC subsystems by taking a given system efficiency minimum value as an evaluation index in real time according to the load change condition; under different use scenes, the minimum value of the system efficiency can be flexibly changed according to scene load characteristics, and the balance between the overall efficiency and the service life optimization of the multi-stack PEMFC power generation system is sought.
The invention greatly reduces the start-stop times of each stack of the system while ensuring that the efficiency value of the whole system is above the set minimum value when the multi-stack PEMFC power generation system is in operation, delays the overall voltage drop caused by start-stop, prolongs the service life of the system, reduces the maintenance cost and improves the whole performance of the multi-stack PEMFC power generation system.
Drawings
FIG. 1 is a schematic flow chart of a start-stop coordination control method of a multi-stack PEMFC power generation system considering life optimization;
FIG. 2 is a schematic diagram of a multi-stack PEMFC power generation system according to an embodiment of the present invention;
FIG. 3 is a graph showing the variation of the efficiency of a single stack PEMFC system with the output power according to the embodiment of the present invention;
FIG. 4 is a graph showing overall system efficiency versus output power for different numbers of Shan Dui PEMFC subsystems in an embodiment of the present invention;
FIG. 5 is a flow chart of a coordinated control method according to an embodiment of the present invention;
FIG. 6 is a graph showing power requirements over time for testing in an embodiment of the present invention;
FIG. 7 is a graph showing the comparison of the opening count of the coordinated control method and the conventional power distribution method when the demand changes in the embodiment of the present invention;
fig. 8 is a graph showing efficiency curves of the coordinated control method and the conventional power distribution method when the demand changes in the embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
As shown in fig. 1, the invention provides a start-stop coordination control method of a multi-stack PEMFC power generation system considering life optimization, which comprises the following steps:
s10, establishing a topological structure of a multi-stack PEMFC power generation system formed by connecting a plurality of identical single-stack PEMFC systems in parallel; the topological structure of the multi-stack PEMFC power generation system is formed by adopting a parallel topology mode by a plurality of single-stack PEMFC systems so as to increase the redundancy of the PEMFC systems and improve the power level and the stability of the system; the single-pile PEMFC system comprises PEMFC stacks and DC/DC converters, each PEMFC stack is cascaded with one DC/DC converter and is connected with a direct current bus, and the multi-pile PEMFC power generation system under the topological structure can realize independent operation and control of the single-pile PEMFC subsystem and can also be put into operation while keeping multiple piles to operate one by one or simultaneously;
analyzing the influence of the aging factors of the PEMFC and the influence of the start-up and shutdown conditions on the residual service life of the PEMFC: when the PEMFC is started or stopped, problems such as carbon carrier corrosion are easily caused. When the PEMFC is started, hydrogen enters an anode flow channel containing a large amount of air; when the PEMFC is stopped, air can diffuse into the anode containing residual hydrogen, and the two processes can form a hydrogen-air interface to accelerate the corrosion of the carbon carrier of the catalytic layer, thereby negatively affecting the durability of the PEMFC;
the aging of the PEMFC is mainly influenced by four working conditions including start-stop, load-changing, low-power operation and high-power operation, and the voltage of the PEMFC is reduced after each working condition is operated, so that the total voltage of the PEMFC is reduced in the whole service cycle as follows:
ΔU fc ＝U on/off ·n 1 +U loadchange ·n 2 +U lowpower ·t 1 +U highpower ·t 2
in U on/off 、U loadchange 、U lowpower 、U highpower Representing the voltage degradation rate of the PEMFC during start-stop, load-changing, low-power operation and high-power operation respectively; n is n 1 、n 2 、t 1 、t 2 Representing the start-stop times, the load-changing times, the low-power interval operation time and the high-power interval operation time respectively; when the overall voltage drop reaches a set value, the service life of the PEMFC is considered to be ended;
the residual service life of the PEMFC is affected by four working conditions of start-stop, load change, low-power operation and high-power operation, and the ratio of the residual service life of the PEMFC is approximately 33%, 56.5%, 4.7% and 5.8% respectively;
s30, calculating the efficiency of the single-stack PEMFC system, and obtaining the change relation of the efficiency of the single-stack PEMFC system along with the output power; drawing efficiency change curves with output power when different numbers Shan Dui PEMFC subsystems are started according to actual test data;
the efficiency of the PEMFC power generation system mainly comprises the fuel utilization rate, the electric pile conversion efficiency and the system electric efficiency, and the calculation formula of the single-pile PEMFC system efficiency is as follows:
η fc_sys ＝η fuel ·η conv ·η elec ；
wherein eta is fuel 、η conv 、η elec Fuel utilization rate, stack conversion efficiency and system electrical efficiency;
the saidFuel utilization rate eta fuel For the ratio between the hydrogen consumed by the PEMFC and the hydrogen supplied to the PEMFC, the hydrogen of the multi-stack PEMFC power generation system is recycled, so that the ratio is generally 99% -100%, and the calculation formula is as follows:
in the method, in the process of the invention,the chemical energy of the consumed hydrogen, the chemical energy of the entering hydrogen, the mass of the consumed hydrogen and the mass of the entering hydrogen are respectively.
The pile conversion efficiency eta conv Generating electric energy E for PEMFC stack Chemical energy E with consumed Hydrogen H2_consummed The ratio between the output voltage V of the PEMFC and the output voltage V of the PEMFC C And heat of reaction E heat The calculation formula is as follows:
the system electrical efficiency eta elec Output energy E for PEMFC net And generating energy E stack The ratio between the electric efficiency E of the PEMFC power generation system of auxiliary equipment such as an air compressor and the like aux /E stack And efficiency eta of unidirectional DC/DC converter DC/DC The composition and the calculation formula are as follows:
according to actual test data, drawing efficiency-to-output power change curves of different numbers of single-stack PEMFC systems when the single-stack PEMFC systems are started: according to the actual running characteristics of the system, collecting and calculating the output power and the overall system efficiency of different numbers of Shan Dui PEMFC subsystems under the actual working condition, and drawing characteristic curves of the overall system efficiency along with the change of the output power when the different numbers Shan Dui PEMFC subsystems are started;
s40, determining a high-efficiency range of the system according to a use scene, reasonably starting and stopping each single-stack PEMFC subsystem by using an efficiency minimum value of a range interval as an evaluation index through a start-stop coordination control method of the multi-stack PEMFC power generation system, and greatly reducing the start-stop times of each stack of the system while ensuring that the multi-stack PEMFC power generation system stably operates at higher efficiency, prolonging the service life of the system and reducing the maintenance cost;
according to the high-efficiency range of the system determined by the use scene, by using a start-stop coordination control method of the multi-stack PEMFC power generation system, each single-stack PEMFC subsystem is reasonably started and stopped by taking the lowest efficiency value of the range interval as an evaluation index, and the start-stop times of each stack of the system are greatly reduced while the stable operation of the multi-stack PEMFC power generation system with higher efficiency is ensured: determining a high efficiency range of the system according to a characteristic curve of the overall system efficiency changing along with the output power and according to a use scene, judging whether to start or stop a single-stack PEMFC subsystem to maintain the overall system efficiency value within a given high efficiency range of the system, namely determining the number of stacks running in real time;
when the overall efficiency of the k single-stack PEMFC subsystems is larger than or equal to a given system efficiency minimum value, a new electric stack is not required to be put in; when the load power is gradually increased and the overall system efficiency is reduced to a given minimum system efficiency value, the (k+1) th single-stack PEMFC subsystem is required to be input so as to improve the overall system efficiency; the power is the (k+1) th single-stack PEMFC subsystem start turning power P (k)h,max When the load power P load Less than P (k)h,max When the load power is shared by the top k single-stack PEMFC subsystems, the load power is shared by the top k single-stack PEMFC subsystems FCk Is of the formula:
P load ＝P FC1 +P FC2 +…+P FCk
P FC1 ＝P FC2 ＝…＝P FCk
when the overall efficiency of the k single-stack PEMFC subsystems is greater than or equal to a given system efficiency minimum value, the running electric stack does not need to be withdrawn; as the load power gradually decreases, the overall system efficiency drops to a given system efficiencyWhen the rate is the lowest, the kth single stack PEMFC subsystem needs to be withdrawn so as to improve the efficiency of the whole system; the power is the turning power P of the kth single-stack PEMFC subsystem (k)h,min When the load power P load Greater than P (k)h,min When the load power is shared by the first k single-stack PEMFC subsystems;
the multi-stack PEMFC power generation system automatically judges the number of the start-stop single-stack PEMFC subsystems according to the load change condition in real time and by taking a given minimum system efficiency value as an evaluation index; the system has the advantages that the stable operation of the multi-stack PEMFC power generation system with higher efficiency is ensured, the start and stop times of each stack of the system are greatly reduced, the service life of the system is prolonged, and the maintenance cost is reduced.
In order to cooperate with the implementation of the method of the invention, based on the same inventive concept, as shown in fig. 2, the invention provides a multi-stack PEMFC power generation system, which comprises a Shan Dui PEMFC subsystem, a controller, auxiliary equipment and a direct current bus;
the Shan Dui PEMFC subsystem comprises PEMFC stacks and DC/DC converters, each PEMFC stack is connected with a DC/DC converter in a cascading way and is connected with a DC bus, and the DC/DC converters ensure that the output voltage of the single-stack PEMFC system is matched with the required DC bus voltage; the controller controls a DC/DC converter, auxiliary equipment and the like in each single-stack PEMFC system, ensures that each single-stack PEMFC subsystem realizes independent control, and puts Shan Dui PEMFC subsystems into operation while keeping multiple stacks one by one or simultaneously; the auxiliary equipment mainly comprises reactant supply equipment, a power converter, a thermal management system and the like, and the normal operation of the multi-stack PEMFC power generation system is ensured under the control of the controller; and the direct current bus is connected with a plurality of single-stack PEMFC subsystems in parallel and is connected with a load.
In this embodiment, the system application scenario is set to provide power for the building body fixedly, the example uses a fuel cell stack with rated power of 70kW, as shown in fig. 3, the highest efficiency value of the single stack PEMFC subsystem is 48.9%, and the lowest efficiency value of the system is set according to 90% of the highest efficiency value, in this embodiment, the lowest efficiency value of the system is 44%; the single-stack PEMFC subsystem stops turning power P h,min For 14.6kW, the efficiency is increased gradually with the increase of the load powerRising to the highest efficiency value, gradually reducing to the lowest system efficiency value again, and starting the turning power P h,max 51.1kW, so the high efficiency range of the single-stack PEMFC subsystem under the application scene is 14.6kW-51.1kW.
The invention is illustrated by taking 4 sets of multi-stack PEMFC power generation systems consisting of the same single-stack 70kW PEMFC subsystems as an example, according to actual test data, acquiring and calculating the output power and the overall system efficiency of 1 to 4 single-stack PEMFC subsystems in the system operation scene in the embodiment, and drawing the characteristic curve of the overall system efficiency variation along with the output power when the 1 to 4 single-stack PEMFC subsystems are started, wherein the high efficiency range of the system is 14.6kW to 204.2kW as shown in figure 4.
And judging whether to start or stop the single-stack PEMFC subsystem to maintain the overall system efficiency value within a given system high efficiency range according to the characteristic curve of the overall system efficiency changing along with the output power and the system high efficiency range, namely determining the number of stacks running in real time. Fig. 4 is a diagram of system efficiency at different power levels for different numbers of battery on, and high power range and start-stop nodes.
The coordination control method is shown in fig. 5, when the load power P load When the starting number k is changed, whether the efficiency is in the high efficiency range or not is judged, if the efficiency is in the high efficiency range, the starting number k is not changed, and the operation of k fuel cells is continued. If the system is not in the high efficiency range under the condition of the current opening number k, the load power P is further judged load Whether to increase or decrease. When the load power P load If the fuel cell is reduced, one cell is stopped, and the rest k-1 cells are shared until the number of the fuel cells is started to be 1, and only the load power P is used load When the number of the fuel cells is 0, the starting number of the fuel cells is 0; when the system is not in a high efficiency range and P load When the number of the batteries increases, one battery is started, and k+1 batteries are shared until all the batteries are started.
Under the condition that the load power of fig. 6 is changed frequently, the start-stop condition of each battery and the start-stop condition and efficiency of the traditional distribution method are respectively shown in fig. 7 and 8, and the efficiency is improved compared with that of the traditional distribution method by using the coordination control method, and under the load condition of fig. 6, the start-stop times are 5 times; under the traditional power distribution method, the starting and stopping times are up to 8 times, and the starting times of the fuel cell are reduced by 37.5 percent. The start-stop coordination control method can judge whether to start or stop a single-stack PEMFC subsystem in real time to maintain the overall system efficiency value within a given system high-efficiency range, namely, the number of stacks running in real time is determined, the start-stop times of each stack of the system are greatly reduced while the multi-stack PEMFC power generation system is ensured to run within the given high-efficiency range, the service life of the system is prolonged, and the maintenance cost is reduced.
The foregoing has shown and described the basic principles and main features of the present invention and the advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (8)
1. A start-stop coordination control method of a multi-stack PEMFC power generation system considering life optimization is characterized by comprising the following steps: the method comprises the following steps:
s10: establishing a topological structure of a multi-stack PEMFC power generation system formed by connecting a plurality of identical single-stack PEMFC systems in parallel;
s20: calculating the efficiency of a single-stack PEMFC system, and obtaining the change relation of the efficiency of the single-stack PEMFC system along with the output power; drawing efficiency change curves with output power when different numbers Shan Dui PEMFC subsystems are started according to actual test data;
s30: according to the high-efficiency range of the system, through a start-stop coordination control method of the multi-stack PEMFC power generation system, each single-stack PEMFC subsystem is reasonably started and stopped by taking the lowest efficiency value of the range interval as an evaluation index, the start-stop times of each stack of the system are greatly reduced while the stable operation of the multi-stack PEMFC power generation system with higher efficiency is ensured, the service life of the system is prolonged, and the maintenance cost is reduced.
2. The life-optimized multi-stack PEMFC power generation system start-stop coordination control method according to claim 1, wherein the method comprises the following steps: in step S10, the established topological structure of the multi-stack PEMFC power generation system is formed by adopting a parallel topology mode by a plurality of single-stack PEMFC systems so as to increase the redundancy of the PEMFC system and improve the power level and the stability of the system; each single-pile PEMFC system comprises a PEMFC pile and a DC/DC converter, each PEMFC pile is cascaded with one DC/DC converter and is connected with a direct current bus, and the multi-pile PEMFC power generation system under the topological structure can realize independent operation and control of the single-pile PEMFC subsystem and can also be put into operation while keeping multiple piles one by one or simultaneously.
3. The life-optimized multi-stack PEMFC power generation system start-stop coordination control method according to claim 1, wherein the method comprises the following steps: in step S30, the PEMFC power generation system efficiency mainly comprises fuel utilization rate, stack conversion efficiency and system electrical efficiency, and single stack PEMFC system efficiency η fc_sys The calculation formula is as follows:
η fc_sys ＝η fuel ·η conv ·η elec
wherein: η (eta) fuel Is the fuel utilization rate eta conv Is the conversion efficiency eta of the galvanic pile elec For system electrical efficiency.
4. The life-optimized multi-stack PEMFC power generation system start-stop coordination control method according to claim 3, wherein the method comprises the following steps: in step S30, the fuel utilization rate η fuel For the ratio between the hydrogen consumed by the PEMFC and the hydrogen supplied to the PEMFC, the hydrogen of the multi-stack PEMFC power generation system is recycled, and the calculation formula is as follows:
wherein:chemical energy for consuming hydrogen, +.>Chemical energy for entering hydrogen, +.>For the mass of hydrogen consumed, +.>Is the mass of hydrogen gas that enters.
5. The life-optimized multi-stack PEMFC power generation system start-stop coordination control method according to claim 3, wherein the method comprises the following steps: in step S30, the pile conversion efficiency η conv Generating electric energy E for PEMFC stack Chemical energy with consumed hydrogenThe ratio between the output voltage V of the PEMFC and the output voltage V of the PEMFC C And heat of reaction E heat The calculation formula is as follows:
6. the life-optimized multi-stack PEMFC power generation system start-stop coordination control method according to claim 3, wherein the method comprises the following steps: in step S30, the system electrical efficiency η elec Output energy E for PEMFC net And generating energy E stack The ratio between the electric efficiency E of the PEMFC power generation system of auxiliary equipment such as an air compressor and the like aux /E stack And efficiency eta of unidirectional DC/DC converter DC/DC The composition and the calculation formula are as follows:
7. the life-optimized multi-stack PEMFC power generation system start-stop coordination control method according to claim 1, wherein the method comprises the following steps: in step S30, according to actual test data, a curve of efficiency with output power change when the single-stack PEMFC systems with different numbers are started is drawn: according to the actual operation characteristics of the system, the output power and the overall system efficiency of different numbers of Shan Dui PEMFC subsystems under the actual working condition are acquired and calculated, and the characteristic curves of the overall system efficiency of different numbers Shan Dui PEMFC subsystems along with the change of the output power are drawn.
8. The life-optimized multi-stack PEMFC power generation system start-stop coordination control method according to claim 1, wherein the method comprises the following steps: in step S40, a high efficiency range of the system is determined according to the usage scenario, and by using a start-stop coordination control method of the multi-stack PEMFC power generation system, each single-stack PEMFC subsystem is reasonably started and stopped by taking the lowest efficiency value of the range interval as an evaluation index, so that the start-stop times of each stack of the system are greatly reduced while the stable operation of the multi-stack PEMFC power generation system with higher efficiency is ensured. Determining a high efficiency range of the system according to a characteristic curve of the overall system efficiency changing along with the output power and a use scene, judging whether to start or stop a single-stack PEMFC subsystem to maintain the overall system efficiency value within the given high efficiency range of the system, namely determining the number of stacks running in real time;
when the overall efficiency of the k single-stack PEMFC subsystems is larger than or equal to a given system efficiency minimum value, a new electric stack is not required to be put in; when the load power is gradually increased and the overall system efficiency is reduced to a given minimum system efficiency value, the (k+1) th single-stack PEMFC subsystem is required to be input so as to improve the overall system efficiency; the power is the (k+1) th single-stack PEMFC subsystem start turning power P (k)h,max When the load power P load Less than P (k)h,max When the load power is shared by the top k single-stack PEMFC subsystems, the load power is shared by the top k single-stack PEMFC subsystems FCk Is of the formula:
P load ＝P FC1 +P FC2 +…+P FCk
P FC1 ＝P FC2 ＝…＝P FCk
when the overall efficiency of the k single-stack PEMFC subsystems is greater than or equal to a given system efficiency minimum value, the running electric stack does not need to be withdrawn; when the load power is gradually reduced and the overall system efficiency is reduced to a given minimum system efficiency value, the kth single-stack PEMFC subsystem needs to be withdrawn so as to improve the overall system efficiency; the power is the turning power P of the kth single-stack PEMFC subsystem (k)h,min When the load power P load Greater than P (k)h,min When the load power is shared by the first k single-stack PEMFC subsystems;
and the multi-stack PEMFC power generation system automatically judges the number of the start-stop single-stack PEMFC subsystems according to the load change condition in real time by taking a given minimum system efficiency value as an evaluation index.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310471301.1A CN116613724A (en) | 2023-04-27 | 2023-04-27 | Multi-stack PEMFC power generation system start-stop coordination control method considering life optimization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310471301.1A CN116613724A (en) | 2023-04-27 | 2023-04-27 | Multi-stack PEMFC power generation system start-stop coordination control method considering life optimization |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116613724A true CN116613724A (en) | 2023-08-18 |
Family
ID=87680955
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310471301.1A Pending CN116613724A (en) | 2023-04-27 | 2023-04-27 | Multi-stack PEMFC power generation system start-stop coordination control method considering life optimization |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116613724A (en) |
-
2023
- 2023-04-27 CN CN202310471301.1A patent/CN116613724A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Das et al. | Recent advances and challenges of fuel cell based power system architectures and control–A review | |
| US7682719B2 (en) | Method for adaptive prediction of stack voltage in automotive fuel cell systems | |
| CN101521288B (en) | Adaptive gain scheduled control for current limitation based on voltage performance of a fuel cell system | |
| US20180108925A1 (en) | Apparatus and Method for Diagnosing State of Fuel Cell Stack | |
| US8404392B2 (en) | Method of entering and exiting a regenerative/stand-by mode on a fuel cell system where the fuel cell is separated from the regenerative source by a blocking power diode | |
| KR101989388B1 (en) | Fuel cell control system | |
| CN103682401B (en) | Power is provided for fuel cell pack in standby period | |
| Mitra et al. | A comprehensive review on fuel cell technologies and its application in microgrids | |
| CN113839066A (en) | Multi-pile integrated long-life fuel cell system | |
| US20140072887A1 (en) | Oxidation of fuel cell electrode contaminants | |
| CN117352790A (en) | Operation efficiency optimization method of multi-module fuel cell power generation system | |
| CN116979099A (en) | Method for relieving steady-state operation attenuation of proton exchange membrane fuel cell | |
| CN116613724A (en) | Multi-stack PEMFC power generation system start-stop coordination control method considering life optimization | |
| Satpathy et al. | Mathematical modelling and voltage control of fuel cell | |
| CN212461751U (en) | Fuel cell and control system thereof | |
| CN111162297B (en) | Proton exchange membrane fuel cell single sheet and method for selecting and quantifying cell stack working condition | |
| CN115188991A (en) | Hydrogen fuel cell device | |
| KR20180117979A (en) | Apparatus for controlling operation of fuel cell and method thereof | |
| Ali et al. | Intelligent hybrid energy system and grid integration using microcontrollers | |
| CN111180761A (en) | Method for releasing residual energy when vehicle-mounted fuel cell is shut down | |
| Mitra et al. | Modelling proton exchange membrane fuel cell for power generation using multi-stage power conversion system | |
| CN114142071B (en) | Combined heat and power operation method and system for multi-stack solid oxide fuel cell | |
| Xie et al. | Dynamic Modeling and Control of High Temperature PEM Fuel Cell and Battery System for Electrical Applications | |
| KR101572033B1 (en) | Apparatus for activating of fuel cell stack | |
| Pala | Fuel cell system and their technologies: a review |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |