Solid Oxide Fuel Cell Power Generation Research Articles

(Invited) The SOFC Program at the DOE’s Office of Fossil Energy and Carbon Management (FECM) and National Energy Technology Laboratory (NETL)

The Solid Oxide Fuel Cell (SOFC) Program, managed by the U.S. Department of Energy (DOE) Office of Fossil Energy (FE) and administered by the FE’s National Energy Technology Laboratory (NETL) is currently developing low-cost SOFC power generation systems. SOFC power systems have the potential to achieve greater than 60 percent efficiency. The SOFC’s operating temperature is lower than combustion-based processes and precludes NOx formation. In addition, there are near-zero emissions of CO2, criteria pollutants, and particulates. Furthermore, SOFC power systems require approximately one-third the amount of water relative to conventional combustion-based power systems. The Program includes the testing of SOFC with natural gas in distributed applications, including data centers. In addition to SOFC, there are several projects on various aspects of high temperature solid oxide electrolysis cell (SOEC) for electrolysis of water. The development of efficient systems for hydrogen production is very interesting, especially when supplementary heat is provided from solar or other waste heat sources such as nuclear or coal power plants.

Layout design and performance evaluation of hydrogen-fueled solid oxide fuel cell power generation system

This study aims to design different layouts of hydrogen-fueled solid oxide fuel cell (SOFC) power generation systems and evaluate their performance differences from a thermodynamic perspective. According to the location of the afterburner and the heat transfer sequence of the gases, the system is divided into three groups of configurations, which are subdivided into 11 layouts. A comparative study is conducted to select the optimal system layout. To simulate the SOFC power generation system, a mathematical model of the SOFC stack and an iterative solution algorithm are developed to better fit the actual operation of the entire system. A single standard evaluation is conducted on the different system layouts from the perspectives of electric power output, total energy efficiency, and temperature uniformity between the SOFC anode and cathode inlet gases. Significant differences are found between these system layouts under two operating modes, fixed gas utilization and fixed gas flow, and each layout has its own advantages and disadvantages under various standards. To further evaluate the system performance, various indicators are normalised, and a comprehensive multi-indicator evaluation method is established. The results show that under high-current conditions at fixed gas utilization, the layout of direct combustion of the SOFC off-gases followed by the preheating of the anode and then the cathode inlet gases exhibit the optimal comprehensive performance. In the fixed gas flow operating mode, where each system reaches the peak power, the layout of the cathode and anode off-gases preheating their respective inlet gases before combustion exhibits the best overall performance.

Techno-economic and thermodynamic analysis of solid oxide fuel cell combined heat and power integrated with biomass gasification and solar assisted carbon capture and energy utilization system

A new system involving biomass gasification (BioG) with solid oxide fuel cell (SOFC) in combined heat and power (CHP) manner is evaluated. The aim of this system is to efficiently utilize biomass, while solar-assisted solid oxide electrolyzer cell (SOEC) methanation exploits CO2 from the system exhaust. CO2 and H2O are co-electrolyzed to form syngas, followed by four step methanation to produce synthetic natural gas. The energy system is thoroughly assessed using energy, exergy, exergoeconomic, and environmental assessments. The BioG-SOFC-CHP overall energy and exergy efficiencies reach up to 59 % and 44.7 %, respectively. Additionally, the SOEC-methanation subsystem achieved overall energy and exergy efficiencies of 78.5 % and 73.8 %, respectively. BioG showed the largest exergy destruction of 78.34 kW compared to 12.3 kW for SOFC. In SOEC-methanation subsystem, heater 2 has the largest exergy destruction of 98.93 kW. The economic analysis showed that the methane selling price of 18 $/GJ and the electricity tariff of 0.13 $/kW, which are nearly identical to the market price, resulting in a payback period of 10 years. Exergoeconomic analysis showed cost rate of SOFC power generation and methane production of 0.05225$/kWh and 29.5$/GJ, respectively. The BioG-SOFC-CHP provided low CO2 emission of about 0.13–0.166 t/GJ, which indicates its low environmental impact.

Evaluation of monolith catalyst in catalytic combustion of anode off-gas for solid oxide fuel cell system

Solid oxide fuel cells (SOFC) can operate at high temperatures (> 650 °C) and have attracted attention because of their high efficiency. However, the CH4, CO, and H2 contained in the anode off-gas that are not reformed or does not participate in the SOFC power generation process must be treated. A catalytic combustion process, which can improve the efficiency by treating the target substances and heat recovery, is essential for this purpose. This study examined the CH4 combustion performance of Pd- and Pt-supported catalysts in the presence or absence of H2O in the feed, at O2/2CH4 ratios of 15 and 20, at a gas hourly space velocity (GHSV) of 5000, 10,000, and 20,000 h−1, and at inlet temperatures of 100–580 °C. The Pd-rich catalyst with a cell per square inch of 400 exhibited the best CH4 combustion performance, as CH4 combustion was possible even at an inlet temperature of 200–300 °C. The performance of this catalyst was evaluated by applying it to a 5-kW scale catalytic combustor. CH4, CO, and H2 combustion experiments of the catalyst in this apparatus were performed at a O2/C of 12–15, GHSV of 8400–16,800 h−1, and inlet temperatures of 100–580 °C, and CO and H2 conversions exceeding 98 % and a CH4 conversion exceeding 75 % were obtained. We expect that the results of this study can be used for the scale-up design of high-efficiency SOFC systems capable of reducing the concentrations of emitted CO and CH4 and utilize the heat generated in the power generation process through the AOG catalytic combustor.

External temperature field test and leakage fault diagnosis for SOFC stacks

The uniformity of Solid Oxide Fuel Cell (SOFC) stacks largely affects the stability and performance of the SOFC power generation system with multiple stacks. However, the health conditions of the stacks are usually assessed by the long-time electrochemical performance test, and some small faults are not able to be quickly identified when the I–V performances have small differences. In this paper, a non-contact temperature sensor array constructed by thermocouples is proposed for NDE (non-destructive evaluation) application in SOFC stacks. The temperature sensor array is fixed near the outer surfaces of the 1 kW-class stack to measure the external temperature field of the stack. Based on the experimental results, it is found that the proposed method is feasible for the examination of the external temperature field of stacks under different operation conditions, which helps to screening the stacks before assembling to the system. At the same time, a real-time online monitoring of fuel leakage is performed using the temperature sensor array, and stacks with unusual temperature distribution due to the leakages can be quickly recognized by comparing with the healthy stack.

Impact of SOFC Power Generation Plant on Carbon Intensity Index (CII) Calculation for Cruise Ships

The International Maritime Organization (IMO) has recently discussed the introduction of a new design index called the Carbon Intensity Indicator (CII), which is a measure of the total carbon dioxide emissions divided by the amount of cargo carried and by the distance travelled on a one-year basis. In this study, authors have analysed a cruise ship assuming its size, the electrical and thermal power required, and its operative profile. CII is calculated with reference to a 180,000 GRT cruise ship equipped with different possible power plant configurations. Emissions in these scenarios are abated by employing alternative fuels like Liquefied Natural Gas (LNG), a shore connection, or innovative technologies like Solid Oxide Fuel Cells (SOFC). The analysis affirms that a cruise ship powered only by MGO from 2024 will not comply with the CII regulation. Results highlight the potential of LNG in reducing carbon dioxide emissions and, for the reference vessel, the use of LNG alone can guarantee a maximum CII rating up to 2026. The benefits of the installation of 10 MW of SOFC are relevant and similar to the one archived with a power plant composed of dual-fuel internal combustion engines and a shore connection.

Modelling and flow rate control methods for anode tail gas circulation intake system at SOFC

In the solid oxide fuel cell (SOFC) power generation system, the anode tail gas circulation intake system plays an important role in the entire system for efficient and stable operation. Currently, there are relatively few studies on the operating characteristics of claw pump, which works as the core component of the SOFC anode exhaust gas circulation intake system. Based on the prototype of 20 kW SOFC power generation system, this paper builds the emulation testbed for the anode exhaust gas circulation intake system and analyzes the working characteristics of the claw pump in the testbed firstly. The support vector regression (SVR) and Gauss process regression (GPR) methods are then used to establish the characteristics model of the claw pump based on the operation data. According to the verification results, GPR method owns higher prediction accuracy than SVR method in our case. Therefore, the GPR method is adopted to build the flow rate prediction model of the claw pump. Finally, the flow rate control method based on feedforward and model prediction (FMP) with GPR flow rate prediction model is proposed for the built anode tail gas circulation intake system. In experiments, the response time of the FMP method is within 22 s and the overshoot is less than 3.2%, whose performance is better than the traditional flow rate control method, such as PID or model predictive control.

Thermodynamic modeling and exergy investigation of a hydrogen-based integrated system consisting of SOFC and CO2 capture option

The current study deals with the thermodynamic modeling of an innovative integrated plant based on solid oxide fuel cell (SOFC) with liquefied natural gas (LNG) cold energy supply. For the suggested innovative plant the energy, and exergy simulations are fully extended and the plant comprehensively analyzed. According to mathematical simulations of the proposed plant, a MATLAB code has been extended. The results indicate that under considered initial conditions, the efficiencies of SOFC and net power generation calculated 58% and 78%, respectively and the CO2-capture rate is obtained 79 kg/h. This study clearly shows that the integrated system reached high efficiency while having zero emissions. In addition, the efficiencies and net amount of power generation, cooling or heating output and SOFC power generation are discussed in detail as a function of different variables such utilization factor, air/fuel ratio, or SOFC inlet temperature. For enhancing the power production efficiency of SOFC, the net electricity, and CCHP exergy efficiency the plant should run in higher utilization factor and lower air/fuel ration also it's important to approximately set SOFC temperature to its ideal temperature.

Sorption-enhanced propane partial oxidation hydrogen production for solid oxide fuel cell (SOFC) applications

Solid oxide fuel cells (SOFC), as high-temperature fuel supply systems, are regarded as one of the most adaptable technologies in terms of efficiency, flexibility, and environmental friendliness. Catalytic propane partial oxidation is recognized as an efficient gas supply method for SOFC applications. However, incombustible by-product CO2 would decrease the purity of hydrogen, thereby reducing the power of fuel cells. Sorption-enhanced propane partial oxidation is an efficient way to adapt to SOFC operating conditions while improving hydrogen production and reducing carbon dioxide emissions. This paper introduces a cage-like porous Ce1-xCaxMO3-λ (M = Co, Fe and Cu) sorbent for providing high carbon dioxide sorption capacity and improving hydrogen purity over the Ni/Al2O3 catalyst. As obtained, Ce1-xCaxFeO3-λ and Ni/Al2O3 sorbent-catalyst performed the best, with the highest hydrogen yield up to 1654 μmol/gcat·s which was 1055 μmol/gcat·s higher than that of pure Ni/Al2O3. The produced reforming gas is served as a fuel in the proposed SOFC system. A maximum output power density of 581 mW/cm2 was reached. This work offered a simple and viable way of combining inexpensive and robust catalyst-sorbent for sorption-enhanced propane partial oxidation in terms of efficient indirect hydrogen supply toward SOFC power generation.

Catalyst with CeO2 and Ni Nanoparticles on a LaCrO3-Based Perovskite Substrate for Bio-Alcohol Steam Reforming and SOFC Power Generation

A Ni/CeO2–LCeCrN catalyst was developed with a unique hierarchy of exsolved Ni and CeO2 nanoparticles dispersed on a perovskite La0.8Ce0.2–xCr0.85Ni0.15–yO3−δ (LCeCrN) substrate for steam reforming methanol, ethanol, and glycerol, producing reformate gas as fuel for solid oxide fuel cell (SOFC) power generation. Methanol, ethanol, and glycerol are almost completely steam-reformed into H2, CO, and CO2 at 450, 650, and 700 °C at a steam/carbon (S/C) ratio of 1, 2.5, and 4 with a maximum hydrogen yield of 2.2, 5.2, and 6.0 mol, respectively. The catalytic performance of Ni/CeO2–LCeCrN catalyst is durable, with no carbon deposition for methanol and slight carbon deposition for ethanol and glycerol reforming for up to 100 h, due to the presence of CeO2 nanoparticles that enhance water adsorption capability and spillover oxygen to oxidize the deposited carbon. The reformate gas is fed in sequence into the anode of an SOFC single cell for power generation. The maximum power density of the cell is comparable at 650 °C and slightly lower at 700 and 750 °C than that fueled by H2, suggesting that Ni/CeO2–LCeCrN is an excellent catalyst for steam reforming methanol, ethanol, and glycerol to produce reformate gas for SOFC power generation.

Characterizing SOFC Stack Electrochemical Performance at Elevated Pressure

Pressurized operation of high temperature fuel cell stacks is of increasing interest for a variety of applications, including high efficiency, hybrid solid-oxide fuel cell power generation systems. In this presentation, we report on our efforts to characterize the electrochemical performance of 1-kWeand 5-kWe Ceres Power SteelCell solid-oxide fuel cell stacks, with a focus on elevated pressure operation in the range of 2-5 barg. Increased pressure operation requires particular attention to pressure differentials across both the membrane electrode assembly and between the stack and surrounding atmosphere. The effort is part of a five-year U.S. DoE ARPA-E INTEGRATE program to combine the high efficiency of solid-oxide fuel cells with the high efficiency balance-of-plant equipment to demonstrate a 70%-efficient distributed power generator. In this architecture, the highly efficient solid-oxide fuel cells (SOFCs) are placed upstream of an internal combustion engine, where the anode tail gas, consisting of partially converted steam-reformed natural gas, is further utilized by the engine to produce electricity. The stacks are operated between 2-5 barg to maximize overall system efficiency and to increase SOFC power density.Few studies have been reported on SOFC stack operation at elevated pressures. The team at the Colorado School of Mines has designed and operated the pressurized stack test stand shown in the figure to characterize electrochemical performance of various kW-scale SOFC stack test modules developed by Ceres Power, Ltd. Minimizing pressure differentials across the anode and cathode during elevated-pressure operation is of primary concern. Excessive pressure on one side of the cell can cause substantial mechanical stress to the metal-supported membrane-electrode assemblies. Pressure differentials in this work are maintained below the manufacturer’s specifications of +/- 25 mbar at operating pressures of 0-5 barg. In addition to performance measurements at elevated pressures, studies have also been conducted on diluted fuel streams representative of high anode tail-gas recycle and various amounts of internal reforming. The stacks show steady, stable performance over all conditions tested.A fuel feed is produced with mass flow controllers that represents partially, steam-reformed natural gas with anode tail-gas recycle. A natural gas fuel processor will be incorporated into the stand at a later stage of the research program. Reactant gas feeds are preheated in multiple zones to properly control stack temperatures. The insulated stack test module is housed inside of a pressure vessel that has individual pressure control in order to minimize the pressure differentials between the internal flow channels of the stack and the surrounding environment. Exhaust gases exit the pressure vessel where heat exchangers are utilized to partially cool the 600°C gases before reaching back-pressure regulators.Stack operation is challenging because of the combination of a tight thermal operating window and the long system response time to changes in inlet conditions. These time constants become even larger at low air flow rates. Lower air flow (while maintaining required oxygen utilization) is desired in order to reduce the power required by the balance of plant, especially when operating at higher pressures. In order to mitigate this, a model predictive controller is being implemented. A dynamic model of the fuel cell was first tuned and validated against experimental transient response data. Then the resulting model was linearized at multiple operating points. The linearizations were then utilized within a gain-scheduled moving-horizon predictor that can take past input and output data, along with a proposed future input, and predict the future output response. The predictor performance has been validated, and then inserted into a model-predicative controller. Optimization algorithms select the input temperatures, flow rates, and electric current required to quickly reach a desired operating condition while meeting all operational constraints, including thermal constraints.In this talk, we will present our findings on the electrochemical performance of 1 and 5-kWe Ceres Power SteelCell stack test modules and the effects of pressure, fuel composition, anode recycle, and degree of internal reforming on stack performance. Results influence the design and net efficiency of the hybrid system. The trajectory of the research will be discussed. Figure 1

Optimization of Methane Reforming for High Efficiency and Stable Operation of SOFC Stacks

: Solid Oxide Fuel Cells (SOFCs) is an efficient and clean pathway to generate electricity. In addition to hydrogen, SOFCs also provide the possibility for the utilization of a variety of carbon containing fuels. However, the application of carbon-based fuels in SOFC remains to be further studied. In this study, an external reformer was used to create appropriate reforming syngas from methanol and avoid carbon deposition. The performance and the efficiency of SOFC were researched with methanol-reformed syngas as fuel. The thermodynamic calculation and experimental work of water vapor reforming reaction of methanol fuel were carried out to study the composition of reforming gas under different temperature and steam-carbon ratio conditions, where the experimental results and the computational results matched well. The mole fraction of hydrogen in reformed syngas was about 55% within the temperature of 700~800 ℃, nevertheless, this value reached 70% if the moisture was removed. Therefore, the reformed syngas should be applied to SOFCs before being condensed and dried. Based on the comparison between the experimental results and the calculated ones, the appropriate components were selected to prepare the reforming syngas, feeding into the anode of SOFC to test the performance and the efficiency. Optimal temperature and steam-carbon ratio conditions for methanol vapor reforming were obtained. Under these conditions, the power density of SOFC exceeded 0.4 W/cm2 and the efficiency reached 50% (LHV). The main conclusions confirmed the high efficiency and feasibility of the methanol-fueled SOFC power generation system.

(Plenary) Update on the SOFC Program at the DOE’s National Energy Technology Laboratory

The Solid Oxide Fuel Cell (SOFC) Program, managed by the U.S. Department of Energy (DOE) Office of Fossil Energy (FE) and administered by the FE’s National Energy Technology Laboratory (NETL) is currently developing low-cost SOFC power generation systems. SOFC power systems have the potential to achieve greater than 60 percent efficiency. The SOFC’s operating temperature is lower than combustion-based processes and precludes NOx formation; there are near-zero emissions of CO2, criteria pollutants, and particulates. Furthermore, SOFC power systems require approximately one-third the amount of water relative to conventional combustion-based power systems. The Program includes the testing of SOFC with natural gas in distributed applications, including data centers. In addition to SOFC, there are several projects on various aspects of high temperature solid oxide electrolysis cell (SOEC) for electrolysis of water. The development of efficient systems for hydrogen production is very interesting, especially when supplementary heat is provided from solar or other waste heat sources such as nuclear or coal power plants.

(Plenary) Update on the SOFC Program at the DOE’s National Energy Technology Laboratory

The Solid Oxide Fuel Cell (SOFC) Program, managed by the U.S. Department of Energy (DOE) Office of Fossil Energy (FE) and administered by the FE’s National Energy Technology Laboratory (NETL), is currently developing low-cost SOFC power generation systems. SOFC power systems have the potential to achieve greater than 60 percent efficiency. The SOFC’s operating temperature is lower than combustion-based processes and precludes NOx formation; there are near-zero emissions of CO2, criteria pollutants, and particulates. Furthermore, SOFC power systems require approximately one-third the amount of water relative to conventional combustion-based power systems. The Program includes the testing of SOFC with natural gas in distributed applications, including data centers. In addition to SOFC, there are several new projects on various aspects of high temperature solid oxide electrolysis cell (SOEC) for electrolysis of water. The development of efficient systems for hydrogen production is very interesting, especially when supplementary heat is provided from solar or other waste heat sources such as nuclear or coal power plants.

Performance test of a 5\xa0kW solid oxide fuel cell system under high fuel utilization with industrial fuel gas feeding

As the demand for green energy with high efficiency and low carbon dioxide (CO2) emissions has increased, solid oxide fuel cells (SOFCs) have been intensively developed in recent years. Integrated gasification fuel cells (IGFCs) in particular show potential for large-scale power generation to further increase system efficiency. Thus, for commercial application of IGFCs, it is important to design reliable multi-stacks for large systems that show long-term stability and practical fuel gas for application to industrial equipment. In this work, a test rig (of a 5 kW SOFC system, with syngas from industrial gasifiers as fuel) was fabricated and subjected to long-term tests under high fuel utilization to investigate its performance. The maximum steady output power of the system was 5700 W using hydrogen and 5660 W using syngas and the maximum steady electrical efficiency was 61.24% while the fuel utilization efficiency was 89.25%. The test lasted for more than 500 h as the fuel utilization efficiency was larger than 83%. The performances of each stack tower were almost identical at both the initial stage and after long-term operation. After 500 h operation, the performances of the stack towers decreased only slightly under lower current and showed almost no change under high current. These results demonstrate the reliability of the multi-stack design and the prospect of this SOFC power-generation system for further enlarging its application in a MWth demonstration.

Thermoeconomic analysis and multi‐objective optimization of a solid‐oxide fuel cell plant coupled with methane tri‐reforming: Effects of thermochemical recuperation

An 80-kW solid-oxide fuel cell (SOFC)-based power plant coupled with methane tri-reforming is proposed and analyzed from the viewpoint of thermoeconomics. In order to integrate the SOFC power generation section with the external reformer, part of the exhaust gases from the afterburner is recycled and utilized as a reformer agent in the reactor. The main challenge in performing the economic analysis is the determination of the costs associated with the tri-reforming process, in particular the reactor cost. To accomplish this, a mathematical procedure is suggested and applied for a fixed-bed reactor based on both the chemical equilibrium and chemical kinetics describing the tri-reforming process. The effects on system performance of important design parameters, including current density, SOFC operating temperature, and exhaust gas recirculation (EGR) percentage, are investigated. The results indicate that system performance is enhanced by using lower values of current density and higher values of SOFC operating temperature. In addition, considering the thermal and environmental performance of system as criteria, the use of EGR is not recommended. However, as the EGR percentage increases, the product unit cost decreases, making EGR advantageous from an economic perspective.

Parametric study on electrodeposition of a nanofibrous LaCoO3 SOFC cathode

Solid oxide fuel cells (SOFCs) capable of operating at low to intermediate temperatures (600–750 °C) are vital for the development of robust SOFC power generation systems. In this regard, the oxygen reduction reaction is the rate-limiting step that requires new highly active catalysts or drastic improvements in the cathode microstructure when using the conventional cathode materials. Here, we report a parametric study on electrodeposition for synthesizing nanostructured cathodes for the SOFCs by producing a nanofibrous LaCoO3 cathode. The synthesis of the nanofibrous LaCoO3 involves preparing an electrically conductive template of carbon nanotubes onto the walls of a porous scaffold made of oxide-ion-conducting material followed by co-electrodeposition of La and Co hydroxides from an aqueous mixed-metal nitrate solution. Then, the deposited metal hydroxides are thermally converted to the LaCoO3 perovskite phase through low-temperature calcination performed at 800 °C. LaCoO3 microstructure is optimized as a function of deposition time, applied current, and solution concentration to obtain a nanofibrous morphology. Anode-supported SOFCs with the nanofibrous LaCoO3 cathode are tested for their electrochemical performance and durability. A durable performance obtained during the 200 h stability tests, performed at 750 and 800 °C and under a galvanostatic load of 1 A cm−2, shows the potential of the electrodeposition for producing robust nanostructured SOFC cathodes.

Optimization of Biogas-Fed Reversible Solid Oxide Fuel Cell System

In this work, an integrated system of biogas tri-reforming and solid oxide fuel cell (SOFC) for power generation was studied by using Aspen Plus simulation. Biogas obtained from a sugar industry with 75%CH4 and 25%CO2 was used as feedstock. However, biogas-feed SOFC power generation system released carbon dioxide (CO2) which was the main cause of global warming. Therefore, solid oxide electrolysis cell (SOEC) was considered for CO2 reduction called reversible solid oxide fuel cell (RSOFC). The RSOFC system included four units; tri-reforming, SOFC, SOEC and methanation. This research aimed to optimize operating conditions of the RSOFC system for generating maximum electricity and reducing CO2. The results of biogas tri-reforming with SOFC system showed that the electrical power production was 6233 W/m2 and CO2 emission was 1603 kg/hr. The results of RSOFC system indicated that CO2 emission was reduced by 24.7%.

(Invited) Current Status of Solid Oxide Fuel Cell Technology and Commercialization

After almost four decades of research and development, considerable progress has now been made in the development and commercialization of solid oxide fuel cells (SOFCs) for clean and efficient power generation. The main advantages of SOFCs are low emissions, fuel flexibility, and high efficiency. The SOFC power generation systems are now sold commercially with units totaling over 500 MW installed or on order, for small residential units (~1 kWe), commercial and industrial systems (100-400 kW), and microgrids (several MW). The most important need to further accelerate commercialization of SOFC technology is to significantly reduce the overall cost of such systems while maintaining adequate performance and performance stability with time. This overview focuses on the designs, materials, processing, and performance of solid oxide fuel cells, and discusses the progress in the deployment of power generation systems built with various design solid oxide fuel cells and their operating experiences. Challenges in reducing cell and system costs are also summarized. SOFCs can also be operated in reverse operating mode for hydrogen and syngas production through electrolysis of steam and mixtures of steam and carbon dioxide; interest in such solid oxide electrolysis has greatly increased during the last decade. Application of solid oxide cells for electrolysis is also discussed in this overview.

Fuzzy Model Predictive Control of Solid Oxide Fuel Cell with Zone Tracking

Abstract Solid oxide fuel cell (SOFC) is of great importance to renewable energy generation system. In practice its output voltage should be held constant and fuel utilization rate should be guaranteed in a reasonable range respectively when the resistance load varies over a large area. In order to overcome the issues in practice, a fuzzy model predictive control with zone tracking for a SOFC power generation system is proposed. The nonlinearity and multivariable coupling are mitigated by fuzzy model and predictive control approaches respectively. The feedforward compensation is adopted to improve with the dynamic response. Zone control is integrated with fuzzy model predictive control for the purposes of satisfying fuel utilization within a desired range. A performance index with a weight function is developed to optimize controlled variables trajectory in the desired range so that the undulations of the controlled variables can be alleviated within the range. The advantages of the proposed method are manifested by simulations.