Wind-solar hybrid power generation hydrogen storage system and fuel cell energy management method thereof
By employing the equivalent hydrogen consumption minimization strategy ECMS and anti-interference PI control in the wind-solar hybrid power generation hydrogen storage system, the energy management of the fuel cell is optimized, solving the problem of power generation fluctuation in the wind-solar power generation system and achieving stable output and extended lifespan of the fuel cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- POWERCHINA HUADONG ENG CORP LTD
- Filing Date
- 2025-12-02
- Publication Date
- 2026-04-17
AI Technical Summary
The fluctuations in power generation from wind and solar power systems lead to unstable operation of fuel cells, affecting their lifespan and hydrogen consumption. There is an urgent need to build an optimized energy management system to achieve stable output and extend lifespan.
A fuel cell energy management method is constructed by adopting a wind-solar hybrid power generation and hydrogen storage system, combined with the equivalent hydrogen consumption minimization strategy ECMS and anti-interference PI control, and optimizing power distribution and hydrogen consumption by adjusting the working status of fuel cells and batteries in real time.
It achieves stability and economy of fuel cell output power under high fluctuating loads, extends the service life of fuel cells and batteries, and reduces hydrogen consumption costs.
Smart Images
Figure CN121886522A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fuel cell technology, specifically to a fuel cell energy management method for power generation in a wind-solar-hydrogen storage system. Background Technology
[0002] With increasing global emphasis on sustainable development, the global energy structure is gradually changing, with renewable energy sources (such as wind and solar power) becoming important energy sources and gradually increasing their share in the energy mix. However, wind and solar power are characterized by intermittency and volatility, often resulting in insufficient power generation to meet demand or unused electricity by the load, leading to phenomena such as wind and solar curtailment. To improve the absorption capacity of energy generation, energy storage is essential. Compared to traditional energy storage methods, hydrogen energy storage offers advantages such as flexible adaptability, low loss, long storage period, no pollution, and no terrain limitations. Utilizing hydrogen energy storage to regulate, store, and convert energy, and alleviate the curtailment problems of wind and solar power hybrid systems, is a current development trend in wind and solar energy application research. Fuel cells are key components in hydrogen energy storage systems, used to consume hydrogen to provide electricity to the load.
[0003] Wind and solar power generation systems are subject to significant uncertainties due to environmental factors such as wind speed and sunlight, leading to fluctuations in the output voltage and power of the power generation system. This, in turn, affects the stable operation and lifespan of fuel cells. Therefore, there is an urgent need to construct an optimized fuel cell energy management system to achieve the goals of optimizing hydrogen consumption, lifespan, and safety and stability. Summary of the Invention
[0004] The purpose of this invention is to provide a fuel cell energy management method for a wind-solar hybrid power generation hydrogen storage system. The method allocates power according to different operating conditions and the ECMS strategy of minimizing equivalent hydrogen consumption, and uses anti-interference PI control to control the output power, so as to meet the dual requirements of high fluctuating load and economy. While reducing hydrogen consumption, it ensures stable output power and extends the service life of fuel cell and battery.
[0005] To achieve the above objectives, according to a first aspect of the present invention, a wind-solar hybrid power generation and hydrogen storage system is provided, characterized in that it includes a wind power generation module, a photovoltaic power generation module, an electrolyzer, a hydrogen storage cylinder, a fuel cell, a storage battery, a DC bus, a converter, a load, and a power grid, wherein the wind power generation module, the photovoltaic power generation module, the electrolyzer, the storage battery, the fuel cell, the load module, and the power grid are all connected to the DC bus respectively.
[0006] The wind power generation module is used to generate AC power through wind energy;
[0007] The photovoltaic power generation module is used to generate direct current through solar energy;
[0008] The electrolyzer is used to absorb excess electrical energy from wind power and photovoltaic power generation, converting electrical energy into chemical energy and electrolyzing water to produce hydrogen.
[0009] The hydrogen storage cylinder is used to store hydrogen produced by the electrolyzer;
[0010] The fuel cell is used to generate electricity by consuming hydrogen.
[0011] The battery is used to store excess electrical energy from the power generation module.
[0012] According to a second aspect of the present invention, the present invention provides an energy management method for a fuel cell in a wind-solar hybrid power generation and hydrogen storage system, comprising the following steps:
[0013] Step S1: During system operation, the power difference P is calculated in real time by comparing the wind and solar power generation with the load demand. net The data acquisition module collects the battery's state of charge (SOC) and the hydrogen content (SHC) of the hydrogen storage tank.
[0014] Step S2: Based on the power difference P net The state of charge (SOC) of the battery and the hydrogen content (SHC) of the hydrogen storage tank are used to determine the operating period of the fuel cell and the battery.
[0015] Step S3: Construct the equivalent hydrogen consumption minimization strategy ECMS; where the input is the power difference P. net And the battery SOC; the output is the output power of the fuel cell and the output power of the battery;
[0016] Step S4: Employ anti-interference PI control to control the output power P of the fuel cell. fc Adjustments were made to bring the actual output power of the fuel cell closer to the allocated power.
[0017] Preferably, the power difference P mentioned in step S1 net The calculation formula is as follows:
[0018] P net =P wind +P pv -P load
[0019] In the formula, P wind P pv P load These are wind power generation capacity, photovoltaic power generation capacity, and load demand power, respectively.
[0020] Preferably, step S2 is based on P net SOC and SHC are used to determine the start-up and shutdown conditions of fuel cells, electrolyzers, and batteries, including:
[0021] Operating Condition 1: When the power generated by the wind power generation module and the photovoltaic power generation module is greater than the load requirement (i.e., P... net >0), judge the battery charging and discharging status based on the SOC level. If SOC ≥ SOC max This indicates that the battery's state of charge has reached its upper limit, and the battery will not charge or discharge. The electrolyzer's operating status is determined by its SHC (Self-Charge Capacity). If SHC ≥ SHC... max This indicates that the hydrogen storage has reached the upper limit of the hydrogen storage tank, and the electrolyzer is not working. At this time, the fuel cell shuts down, and the excess electrical energy is consumed by the power grid.
[0022] Operating Condition 2: When the power generated by the wind power generation module and the photovoltaic power generation module is greater than the load requirement (i.e., P) net >0), SOC <SOC max SHC ≥ SHC max When the electrolyzer and fuel cell are shut down, the battery is charged. Any remaining power is absorbed by the power grid.
[0023] Operating Condition 3: When the power generated by the wind power generation module and the photovoltaic power generation module is greater than the load requirement and the power difference is greater than the minimum operating power of the electrolytic cell (i.e., P) net >P elmin >0), SOC≥SOC max SHC <SHC max When the hydrogen storage tank is not full, the battery is fully charged, the fuel cell and battery are shut down, and the electrolyzer consumes electrical energy to produce hydrogen. Any excess electrical energy is absorbed by the power grid.
[0024] Operating Condition 4: When the power generated by the wind power generation module and the photovoltaic power generation module is greater than the load requirement and the power difference is less than the minimum operating power of the electrolytic cell (i.e., P) elmin >P net >0), SOC≥SOC max SHC <SHC max When the fuel cell is shut down, the battery discharges, and the electrolyzer consumes battery energy to produce hydrogen at minimum operating power.
[0025] Operating Condition 5: When the power generated by the wind power module and the photovoltaic power module is greater than the load requirement and the power difference is less than the maximum charging power of the battery (i.e., P) chgmax >P net >0), SOC <SOC max SHC <SHC max At this time, the fuel cell and electrolyzer are shut down, and the battery is charged.
[0026] Operating Condition 6: When the power generated by the wind power module and the photovoltaic power module exceeds the load requirement, the power difference is greater than the maximum charging power of the battery and the difference between the two is greater than the minimum operating power of the electrolytic cell (i.e., P).net -P chgmax >P elmin >0), SOC <SOC max SHC <SHC max At this time, the fuel cell shuts down, the battery is charged, and the electrolyzer consumes excess energy to produce hydrogen.
[0027] Operating Condition 7: When the power generated by the wind power module and the photovoltaic power module exceeds the load requirement, the power difference is greater than the maximum charging power of the battery and less than the minimum operating power of the electrolytic cell (i.e., P). elmin >P net -P chgmax >0), SOC <SOC max SHC <SHC max When the fuel cell is shut down, the electrolyzer consumes energy to produce hydrogen at minimum operating efficiency, and the battery consumes the remaining electrical energy to charge it.
[0028] Operating Condition 8: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement and the power difference is less than the maximum discharge power of the battery (i.e., P... dismax >-P net >0), SOC>SOC min At this time, the electrolyzer and fuel cell are shut down, and the battery discharges to fill the power gap.
[0029] Operating Condition 9: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is greater than the maximum discharge power of the battery and less than the minimum output power of the fuel cell (i.e., -P). net -P dismax <P fcmin SOC > SOC min SHC>SHC min When the electrolyzer is shut down, the fuel cell operates at minimum output power, and the remaining shortfall is made up by the battery.
[0030] Operating Condition 10: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is greater than the maximum discharge power of the battery and the difference between the two is greater than the minimum output power of the fuel cell (i.e., -P). net -P dismax >P fcmin SOC > SOC min SHC>SHC min When the electrolyzer is shut down, the battery operates at maximum discharge power, and the remaining shortfall is made up by the fuel cell.
[0031] Operating Condition 11: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement and the power difference is greater than the maximum discharge power of the battery (i.e., -P) net >Pdismax >0), SOC>SOC min SHC≤SHC min When the hydrogen content in the storage tank is insufficient and the battery has excess energy, the electrolyzer and fuel cell are shut down, the battery operates at maximum discharge power, and the remaining shortfall is made up by the power grid.
[0032] Operating Condition 12: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is greater than the maximum output power of the fuel cell (i.e., -P). net >P fcmax SOC≤SOC min SHC>SHC min At that time, the electrolyzer and battery are shut down, the fuel cell operates at maximum output power, and the grid fills the remaining gap.
[0033] Operating Condition 13: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is less than the maximum output power of the fuel cell (i.e., -P). net <P fcmax SOC≤SOC min SHC>SHC min At that time, the electrolyzer shuts down, the fuel cell operates to make up for the power shortfall, and the battery uses the remaining electrical energy from the fuel cell to charge.
[0034] Operating Condition 14: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement (i.e., P... net <0), SHC≤SHC min SOC≤SOC min When the hydrogen content in the storage tank and the energy in the battery are insufficient, the fuel cell, electrolyzer, and battery all stop working, and the power grid takes over the energy required for the load.
[0035] Preferably, in step S3, an equivalent hydrogen consumption minimization control strategy (ECMS) is constructed, with fuel cell hydrogen consumption and maintaining battery power output as optimization objectives. An optimization function for the fuel cell, i.e., the equivalent hydrogen consumption minimization objective function, is established as follows:
[0036]
[0037] In the formula, This represents the actual hydrogen consumption rate of the fuel cell. Let t be the equivalent hydrogen consumption rate of the battery, and k(t) be the equivalent factor.
[0038] Further preferred, and It can be calculated using the following formula:
[0039]
[0040] In the formula, P fc P bat The output power of the fuel cell and the storage battery, respectively, η fc For fuel cell efficiency, Because of the low calorific value of hydrogen, η dis η chg These are the battery's discharge efficiency and charging efficiency, respectively.
[0041] A further preferred approach is to use an equivalent factor adjustment method based on SOC feedback. When the battery SOC is smaller than the reference SOC, the equivalent factor is larger, indicating that the proportion of electricity consumption increases under a certain power demand, causing the optimization algorithm to be more inclined to use fuel cell drive. When the battery SOC is larger than the reference SOC, the equivalent factor is smaller, thereby reducing the output of the fuel cell, using more battery energy, and adjusting the SOC to near the reference value.
[0042] Further optimization involves establishing an equivalent factor adjustment formula:
[0043] k(t) = k0 + K p (SOC ref -SOC(t))
[0044] In the formula, k0 is the basic equivalence factor, K p SOC is a proportionality coefficient. ref For reference SOC.
[0045] A further preferred optimization function for the strategy of minimizing equivalent hydrogen consumption can be written as:
[0046]
[0047] Further optimized, the constraints for the ECMS strategy of minimizing equivalent hydrogen consumption are as follows:
[0048]
[0049] In the formula, SOC min SOC max These represent the lower and upper limits of the battery's state of charge, P. fc_min P fc_max P represents the minimum and maximum output power of the fuel cell, respectively. bat_min P bat_max These represent the minimum and maximum output power of the battery, respectively, and ΔP is the maximum rate of change of the fuel cell power.
[0050] Preferably, in step four, anti-interference PI control is used to adjust the output power of the fuel cell, and the power reference value P is adjusted. fcrefDivide by the measured voltage U at the fuel cell terminal fc The reference current value I of the fuel cell was calculated. fcref And compare it with the fuel cell terminal current measurement value I. fc A comparison is then made. A duty cycle signal is generated by the PI controller, which controls the DC-DC converter to adjust the fuel cell's output power. Furthermore, an environmental detection module is added to compensate for external environmental disturbances, improving the PI control's anti-interference capability.
[0051] Further optimization involves establishing a DC-DC triggering equation:
[0052]
[0053] In the formula, K fcp and K fci These are the proportional coefficient and integral time constant for the DC / DC converter trigger control, respectively. μ is the disturbance compensation factor.
[0054] Therefore, the present invention employs the above-mentioned fuel cell energy management method for a wind-solar hybrid power generation and hydrogen storage system, and the beneficial effects are as follows:
[0055] In the operating condition determination process, this invention considers not only traditional determination factors (power difference, SOC, hydrogen content), but also the maximum and minimum operating power of the electrolyzer, fuel cell, and battery, thus optimizing the operating condition determination process and making the energy management strategy more reasonable.
[0056] This invention aims to extend fuel cell life, maintain lithium battery health, and reduce hydrogen costs by constructing an equivalent hydrogen consumption minimization control strategy that takes into account the system's hydrogen consumption and power allocation.
[0057] This invention achieves the regulation of fuel cell output power through anti-interference PI control, thereby increasing the robustness of PI control. Attached Figure Description
[0058] Figure 1 This is a schematic diagram of the wind-solar hybrid power generation and hydrogen storage system in this invention.
[0059] Figure 2 This is a flowchart of the steps of the present invention.
[0060] Figure 3 This is a flowchart illustrating the start / stop determination process for each device in the system of this invention.
[0061] Figure 4 This is a block diagram of the fuel cell control system of the present invention. Detailed Implementation
[0062] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0063] Please see Figure 1 This invention discloses a fuel cell energy management method for a wind-solar hybrid power generation and hydrogen storage system. The wind-solar hybrid power generation and hydrogen storage system includes a wind power generation module, a photovoltaic power generation module, an electrolyzer, a hydrogen storage tank, a fuel cell, a battery, a DC bus, a converter, a load, and a power grid. The wind power generation module, photovoltaic power generation module, electrolyzer, battery, fuel cell, load module, and power grid are all connected to the DC bus.
[0064] The wind power generation module is used to generate AC power through wind energy;
[0065] The photovoltaic power generation module is used to generate direct current through solar energy;
[0066] The electrolyzer is used to absorb excess electrical energy from wind power and photovoltaic power generation, converting electrical energy into chemical energy and electrolyzing water to produce hydrogen.
[0067] The hydrogen storage cylinder is used to store hydrogen produced by the electrolyzer;
[0068] The fuel cell is used to generate electricity by consuming hydrogen.
[0069] The battery is used to store excess electrical energy from the power generation module.
[0070] Please see Figure 2 To rationally start and stop fuel cells, reduce hydrogen consumption, and ensure stable fuel cell output power, this invention provides a fuel cell energy management method for a wind-solar hybrid power generation hydrogen storage system, comprising the following steps:
[0071] Step S1: During system operation, the power difference P is calculated in real time by comparing the wind and solar power generation with the load demand. net The data acquisition module collects the battery's state of charge (SOC) and the hydrogen content (SHC) of the hydrogen storage tank.
[0072] Step S2: Based on the power difference P net The state of charge (SOC) of the battery and the hydrogen content (SHC) of the hydrogen storage tank are used to determine the operating period of the fuel cell and the battery.
[0073] Step S3: Construct the equivalent hydrogen consumption minimization strategy ECMS; where the input is the power difference P. net And the battery SOC; the output is the output power of the fuel cell and the output power of the battery;
[0074] Step S4: Employ anti-interference PI control to control the output power P of the fuel cell. fc Adjustments were made to bring the actual output power of the fuel cell closer to the allocated power.
[0075] Please see Figure 3 Compared to traditional operating condition determination methods that only consider power difference, SOC, and hydrogen content, this invention also considers the difference between the power difference and the maximum and minimum operating power of each device in the determination process, making the determination process more reasonable. Specific operating conditions include:
[0076] Operating Condition 1: When the power generated by the wind power generation module and the photovoltaic power generation module is greater than the load requirement (i.e., P... net >0), judge the battery charging and discharging status based on the SOC level. If SOC ≥ SOC max This indicates that the battery's state of charge has reached its upper limit, and the battery will not charge or discharge. The electrolyzer's operating status is determined by its SHC (Self-Charge Capacity). If SHC ≥ SHC... max This indicates that the hydrogen storage has reached the upper limit of the hydrogen storage tank, and the electrolyzer is not working. At this time, the fuel cell shuts down, and the excess electrical energy is consumed by the power grid.
[0077] Operating Condition 2: When the power generated by the wind power generation module and the photovoltaic power generation module is greater than the load requirement (i.e., P) net >0), SOC <SOC max SHC ≥ SHC max When the electrolyzer and fuel cell are shut down, the battery is charged. Any remaining power is absorbed by the power grid.
[0078] Operating Condition 3: When the power generated by the wind power generation module and the photovoltaic power generation module is greater than the load requirement and the power difference is greater than the minimum operating power of the electrolytic cell (i.e., P) net >P elmin >0), SOC≥SOC max SHC <SHC max When the hydrogen storage tank is not full, the battery is fully charged, the fuel cell and battery are shut down, and the electrolyzer consumes electrical energy to produce hydrogen. Any excess electrical energy is absorbed by the power grid.
[0079] Operating Condition 4: When the power generated by the wind power generation module and the photovoltaic power generation module is greater than the load requirement and the power difference is less than the minimum operating power of the electrolytic cell (i.e., P) elmin >P net >0), SOC≥SOC max SHC <SHC max When the fuel cell is shut down, the battery discharges, and the electrolyzer consumes battery energy to produce hydrogen at minimum operating power.
[0080] Operating Condition 5: When the power generated by the wind power module and the photovoltaic power module is greater than the load requirement and the power difference is less than the maximum charging power of the battery (i.e., P) chgmax >P net >0), SOC <SOC max SHC <SHCmax At this time, the fuel cell and electrolyzer are shut down, and the battery is charged.
[0081] Operating Condition 6: When the power generated by the wind power module and the photovoltaic power module exceeds the load requirement, the power difference is greater than the maximum charging power of the battery and the difference between the two is greater than the minimum operating power of the electrolytic cell (i.e., P). net -P chgmax >P elmin >0), SOC <SOC max SHC <SHC max At this time, the fuel cell shuts down, the battery is charged, and the electrolyzer consumes excess energy to produce hydrogen.
[0082] Operating Condition 7: When the power generated by the wind power module and the photovoltaic power module exceeds the load requirement, the power difference is greater than the maximum charging power of the battery and less than the minimum operating power of the electrolytic cell (i.e., P). elmin >P net -P chgmax >0), SOC <SOC max SHC <SHC max When the fuel cell is shut down, the electrolyzer consumes energy to produce hydrogen at minimum operating efficiency, and the battery consumes the remaining electrical energy to charge it.
[0083] Operating Condition 8: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement and the power difference is less than the maximum discharge power of the battery (i.e., P... dismax >-P net >0), SOC>SOC min At this time, the electrolyzer and fuel cell are shut down, and the battery discharges to fill the power gap.
[0084] Operating Condition 9: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is greater than the maximum discharge power of the battery and less than the minimum output power of the fuel cell (i.e., -P). net -P dismax <P fcmin SOC > SOC min SHC>SHC min When the electrolyzer is shut down, the fuel cell operates at minimum output power, and the remaining shortfall is made up by the battery.
[0085] Operating Condition 10: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is greater than the maximum discharge power of the battery and the difference between the two is greater than the minimum output power of the fuel cell (i.e., -P). net -P dismax >P fcmin SOC > SOC min SHC>SHC minWhen the electrolyzer is shut down, the battery operates at maximum discharge power, and the remaining shortfall is made up by the fuel cell.
[0086] Operating Condition 11: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement and the power difference is greater than the maximum discharge power of the battery (i.e., -P) net >P dismax >0), SOC>SOC min SHC≤SHC min When the hydrogen content in the storage tank is insufficient and the battery has excess energy, the electrolyzer and fuel cell are shut down, the battery operates at maximum discharge power, and the remaining shortfall is made up by the power grid.
[0087] Operating Condition 12: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is greater than the maximum output power of the fuel cell (i.e., -P). net >P fcmax SOC≤SOC min SHC>SHC min At that time, the electrolyzer and battery are shut down, the fuel cell operates at maximum output power, and the grid fills the remaining gap.
[0088] Operating Condition 13: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is less than the maximum output power of the fuel cell (i.e., -P). net <P fcmax SOC≤SOC min SHC>SHC min At that time, the electrolyzer shuts down, the fuel cell operates to make up for the power shortfall, and the battery uses the remaining electrical energy from the fuel cell to charge.
[0089] Operating Condition 14: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement (i.e., P... net <0), SHC≤SHC min SOC≤SOC min When the hydrogen content in the storage tank and the energy in the battery are insufficient, the fuel cell, electrolyzer, and battery all stop working, and the power grid takes over the energy required for the load.
[0090] To rationally allocate power and reduce hydrogen consumption, this invention constructs an equivalent hydrogen consumption minimization control strategy (ECMS), which takes fuel cell hydrogen consumption and maintaining battery power output as optimization objectives, and establishes an optimization function for the fuel cell, namely the equivalent hydrogen consumption minimization objective function.
[0091] The objective function is shown below:
[0092]
[0093] In the formula, This represents the actual hydrogen consumption rate of the fuel cell. Let t be the equivalent hydrogen consumption rate of the battery, and k(t) be the equivalent factor.
[0094] in, and It can be calculated using the following formula:
[0095]
[0096] In the formula, P fc P bat The output power of the fuel cell and the storage battery, respectively, η fc For fuel cell efficiency, Because of the low calorific value of hydrogen, η dis η chg These are the battery's discharge efficiency and charging efficiency, respectively.
[0097] Furthermore, an equivalent factor adjustment method based on SOC feedback is adopted. When the battery SOC is smaller than the reference SOC, the equivalent factor is larger, which means that under a certain power demand, the proportion of electricity consumption increases, causing the optimization algorithm to be more inclined to use fuel cell drive. When the battery SOC is larger than the reference SOC, the equivalent factor is smaller, thereby reducing the output of the fuel cell and using more battery energy to adjust the SOC to near the reference value.
[0098] Furthermore, an equivalent factor adjustment formula is established, as follows:
[0099] k(t) = k0 + K p (SOC ref -SOC(t))
[0100] In the formula, k0 is the basic equivalence factor, K p SOC is a proportionality coefficient. ref For reference SOC.
[0101] Furthermore, the specific optimization function for the strategy of minimizing equivalent hydrogen consumption can be written as:
[0102]
[0103] Furthermore, the constraints for the ECMS strategy of minimizing equivalent hydrogen consumption are established as follows:
[0104]
[0105] In the formula, SOC min SOC max These represent the lower and upper limits of the battery's state of charge, P. fc_min P fc_maxP represents the minimum and maximum output power of the fuel cell, respectively. bat_min P bat_max These represent the minimum and maximum output power of the battery, respectively, and ΔP is the maximum rate of change of the fuel cell power.
[0106] Traditional dual-loop PI control is simple in structure and widely used, but the control parameters are fixed values, making adjustment complex when the system is subject to disturbances. Furthermore, it typically only ensures system steady-state operation when the system is close to its quiescent operating point; larger disturbances can significantly reduce control effectiveness or even cause instability, making it unsuitable for wind-solar hybrid power generation and hydrogen storage systems with high volatility.
[0107] To address the above problems, this invention employs anti-interference PI control; please refer to the principle description. Figure 4 Anti-interference PI control adjusts the fuel cell output power, using the power reference value P. fcref Divide by the measured voltage U at the fuel cell terminal fc The reference current value I of the fuel cell was calculated. fcref And compare it with the fuel cell terminal current measurement value I. fc A comparison is then made. A duty cycle signal is generated by the PI controller, which controls the DC-DC converter to adjust the fuel cell's output power. Furthermore, an environmental detection module is added to compensate for external environmental disturbances, improving the robustness of the PI control.
[0108] Furthermore, the DC-DC triggering equation is established:
[0109]
[0110] In the formula, K fcp and K fci These are the proportional coefficient and integral time constant for the DC / DC converter trigger control, respectively. μ is the disturbance compensation factor.
[0111] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications can be made to the above embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made to the present invention by those skilled in the art based on the disclosure thereof should be within the scope of protection of the present invention.
Claims
1. A wind-solar hybrid power generation and hydrogen storage system, characterized in that: It includes a wind power generation module, a photovoltaic power generation module, an electrolyzer, a hydrogen storage tank, a fuel cell, a storage battery, a DC bus, a converter, a load, and a power grid. The wind power generation module, the photovoltaic power generation module, the electrolyzer, the storage battery, the fuel cell, the load module, and the power grid are all connected to the DC bus. The wind power generation module is used to generate AC power through wind energy; The photovoltaic power generation module is used to generate direct current through solar energy; The electrolyzer is used to absorb excess electrical energy from wind power and photovoltaic power generation, converting electrical energy into chemical energy and electrolyzing water to produce hydrogen. The hydrogen storage cylinder is used to store hydrogen produced by the electrolyzer; The fuel cell is used to generate electricity by consuming hydrogen. The battery is used to store excess electrical energy from the power generation module.
2. A fuel cell energy management method for a wind-solar hybrid power generation and hydrogen storage system, characterized in that, Includes the following steps: Step S1: During system operation, the power difference P is calculated in real time by comparing the wind and solar power generation with the load demand. net The data acquisition module collects the battery's state of charge (SOC) and the hydrogen content (SHC) of the hydrogen storage tank. Step S2: Based on the power difference P net The state of charge (SOC) of the battery and the hydrogen content (SHC) of the hydrogen storage tank are used to determine the operating period of the fuel cell and the battery. Step S3: Construct the equivalent hydrogen consumption minimization strategy ECMS; where the input is the power difference P. net And the battery SOC; the output is the output power of the fuel cell and the output power of the battery; Step S4: Employ anti-interference PI control to control the output power P of the fuel cell. fc Adjustments were made to bring the actual output power of the fuel cell closer to the allocated power.
3. The method according to claim 2, characterized in that, The power difference is achieved through the wind power generation P wind Photovoltaic power generation P pv Load demand power P load The calculation is as follows: P net =P wind +P pv -P load (1)。 4. The method according to claim 2, characterized in that, Based on the power difference P net The system determines different operating conditions based on the hydrogen content (SHC) of the hydrogen storage tank, the state of charge (SOC) of the battery, and the difference between the power difference and the maximum and minimum operating power of each device, including: Operating Condition 1: When the power generated by the wind power module and the photovoltaic power module exceeds the load requirement, the battery charging and discharging status is judged based on the SOC level. If SOC ≥ SOC max This indicates that the battery's state of charge has reached its upper limit, and the battery will not charge or discharge; the electrolyzer's operating status is determined based on SHC, if SHC ≥ SHC max If the hydrogen storage reaches the upper limit of the hydrogen storage tank, the electrolyzer will not work; at this time, the fuel cell will shut down, and the excess electrical energy will be consumed by the power grid. Operating Condition 2: When the power generated by the wind power module and the photovoltaic power module exceeds the load requirement, the SOC... <SOC max SHC ≥ SHC max When the electrolyzer and fuel cell are shut down, the battery is charged; any remaining power is absorbed by the power grid. Operating Condition 3: When the power generated by the wind power generation module and the photovoltaic power generation module is greater than the load requirement and the power difference is greater than the minimum operating power of the electrolytic cell (i.e., P) net >P elmin >0), SOC≥SOC max SHC <SHC max When the hydrogen storage tank is not full, the battery is fully charged, the fuel cell and the battery are shut down, and the electrolyzer consumes electrical energy to produce hydrogen. Any excess electrical energy is absorbed by the power grid. Operating Condition 4: When the power generated by the wind power module and the photovoltaic power module is greater than the load requirement and the power difference is less than the minimum operating power of the electrolytic cell; SOC ≥ SOC max SHC <SHC max When the fuel cell is shut down, the battery discharges, and the electrolyzer consumes battery energy to produce hydrogen at minimum operating power. Operating Condition 5: When the power generated by the wind power module and the photovoltaic power module exceeds the load requirement and the power difference is less than the maximum charging power of the battery; SOC <SOC max SHC <SHC max At this time, the fuel cell and electrolyzer are shut down, and the battery is charged; Operating Condition 6: When the power generated by the wind power module and the photovoltaic power module exceeds the load requirement, the power difference is greater than the maximum charging power of the battery and the difference between the two is greater than the minimum operating power of the electrolytic cell, the SOC (State of Charge) is... <SOC max SHC <SHC max When the fuel cell is shut down, the battery is charged, and the electrolyzer consumes excess energy to produce hydrogen. Operating Condition 7: When the power generated by the wind power module and the photovoltaic power module exceeds the load requirement, the power difference is greater than the maximum charging power of the battery and less than the minimum operating power of the electrolytic cell, the SOC (State of Charge) is... <SOC max SHC <SHC max When the fuel cell is shut down, the electrolyzer consumes energy to produce hydrogen at minimum efficiency, and the battery consumes the remaining electrical energy to charge it. Operating Condition 8: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement and the power difference is less than the maximum discharge power of the battery, SOC > SOC min At this time, the electrolyzer and fuel cell are shut down, and the battery discharges to fill the power gap; Condition 9: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is greater than the maximum discharge power of the battery and less than the minimum output power of the fuel cell, and the SOC > SOC. min SHC>SHC min When the electrolyzer is shut down, the fuel cell operates at minimum output power, and the remaining shortfall is made up by the battery. Operating Condition 10: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is greater than the maximum discharge power of the battery and the difference between the two is greater than the minimum output power of the fuel cell, and SOC > SOC. min SHC>SHC min When the electrolyzer is shut down, the battery operates at maximum discharge power, and the remaining shortfall is made up by the fuel cell. Operating Condition 11: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement and the power difference is greater than the maximum discharge power of the battery, SOC > SOC min SHC≤SHC min When the hydrogen content in the storage tank is insufficient and the battery has excess energy, the electrolyzer and fuel cell are shut down, the battery operates at maximum discharge power, and the remaining shortfall is made up by the power grid. Operating Condition 12: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is greater than the maximum output power of the fuel cell, and the SOC ≤ SOC min SHC>SHC min At this time, the electrolyzer and battery are shut down, the fuel cell operates at maximum output power, and the grid fills the remaining gap; Operating Condition 13: When the power generated by the wind power module and the photovoltaic power module is less than the load requirement, the power difference is less than the maximum output power of the fuel cell, and the SOC ≤ SOC min SHC>SHC min When the electrolyzer is shut down, the fuel cell works to make up for the power shortfall, and the battery uses the remaining power of the fuel cell to charge. Operating Condition 14: When the power generated by the wind power generation module and the photovoltaic power generation module is less than the load requirement, SHC ≤ SHC min SOC≤SOC min When the hydrogen content in the storage tank and the energy in the battery are insufficient, the fuel cell, electrolyzer, and battery all stop working, and the power grid takes over the energy required for the load.
5. The method according to claim 2, characterized in that... With the optimization objectives of hydrogen consumption and maintaining battery power output in the fuel cell, an optimization function for the fuel cell is established, namely, the objective function for minimizing equivalent hydrogen consumption, as shown below: In the formula, This represents the actual hydrogen consumption rate of the fuel cell. Let t be the equivalent hydrogen consumption rate of the battery, and k(t) be the equivalence factor. in, and It can be calculated using the following formula: In the formula, P fc P bat The output power of the fuel cell and the storage battery, respectively, η fc For fuel cell efficiency, Because of the low calorific value of hydrogen, η dis η chg These refer to the battery's discharge efficiency and charging efficiency, respectively.
6. The method according to claim 5, characterized in that, The constraints of the ECMS strategy for minimizing equivalent hydrogen consumption are as follows: In the formula, SOC min SOC max These represent the lower and upper limits of the battery's state of charge, P. fc_min P fc_max P represents the minimum and maximum output power of the fuel cell, respectively. bat_min P bat_max These represent the minimum and maximum output power of the battery, respectively, and ΔP is the maximum rate of change of the fuel cell power.
7. The method according to claim 5, characterized in that... The equivalence factor is a core parameter in the ECMS strategy, used to coordinate the balance between current electricity consumption and future hydrogen consumption. Its value directly affects the power allocation decision. It is adaptively proportionally adjusted based on the basic equivalence factor plus the SOC deviation. k(t)=k0+K p (SOC ref -SOC(t)) (6) In the formula, k0 is the basic equivalence factor, K p SOC is a proportionality coefficient. ref For reference SOC; The smaller the battery SOC is compared to the reference SOC, the larger the equivalence factor, indicating that the proportion of electricity consumption increases under a certain power demand, causing the optimization algorithm to be more inclined to use fuel cell drive. Conversely, the larger the battery SOC is compared to the reference SOC, the smaller the equivalence factor, thereby reducing the output of the fuel cell and using more battery energy to adjust the SOC to near the reference value.
8. The method according to claim 2, characterized in that: The system allocates output power to the fuel cell based on system operating conditions and ECMS strategy, and then uses anti-interference PI control to adjust the power so that the actual output power of the fuel cell is close to the allocated power.
9. The method according to claim 4, characterized in that: Power reference value P fcref Divide by the measured voltage U at the fuel cell terminal fc The reference current value I of the fuel cell was calculated. fcref And compare it with the fuel cell terminal current measurement value I. fc The comparison is performed; then, a duty cycle signal is generated by the PI controller, which controls the DC-DC converter to adjust the output power of the fuel cell; in addition, an environmental detection module is added to compensate for external environmental disturbances and improve the anti-interference capability of the PI control. The DC-DC triggering equation is: In the formula, K fcp and K fci These are the proportional coefficient and integral time constant for triggering control of the DC / DC converter, respectively, and μ is the disturbance compensation factor.