Dynamic analysis and linear control strategies for proton exchange membrane fuel cell using a distributed parameter model

Three-dimensional simulations were performed for proton exchange membrane fuel cell (PEMFC) with thin catalyst-coated membrane (CCM) regarding liquid water cooling design. The studied PEMFC follows a counter-flow pattern for the H2 and air stream, which is commonly adopted in today's automotive PEMFCs. For the thermal modeling of the liquid water, conjugate heat transfer model is used. The cooling flow inlet temperature between 60 and 75°C, direction, flow rate between 0.08 and 0.32 L s−1 m−2 as well as the cooling channel number are investigated, specifically. It is found that the cooling inlet temperature directly determines the working temperature of PEMFC under the same cooling flow rate. It means that increasing the cooling inlet temperature can lift the PEMFC operating temperature. The co-direction for the liquid flow and the air stream is found to be better for PEMFC as it can suppress the liquid water formed near cathode outlet. It is then pointed out that the cooling flow rate would determine the along-channel temperature non-uniformity in PEMFC and moderate flow rate is preferred. Reducing the number of the cooling channels while assigning higher flow rate for each channel will slightly lift the PEMFC temperature overall, but this strategy will result in more pumping power loss.

The performance of proton exchange membrane fuel cells is very sensitive to temperature. The electrochemical reaction results directly in temperature variations in the proton exchange membrane fuel cell. Ensuring effective temperature control is crucial to ensure fuel cell reliability and durability. This paper uses active disturbance rejection control in the thermal management system to maintain the operating temperature and the stack inlet and outlet temperature difference at the set value. First, key cooling system modules such as expansion tanks, coolant circulation pumps and radiators based on Simulink were built. Then, physical modeling and simulation of the fuel cell cooling system was carried out. In order to ensure the effectiveness of the control strategy and reduce the parameter tuning workload, an active disturbance rejection control parameter optimization method using an elite genetic algorithm was proposed. When the optimized control strategy responds to input disturbances, the maximum overshoot of the system is only 1.23% and can reach stability again in 30 s, so the fuel cell temperature can be controlled effectively. Simulation results show that the optimized control strategy can effectively control the stack temperature and coolant temperature difference under the influence of stepped charging current without interference or with interference, and has strong robustness and anti-interference capability.

An effective oxygen excess ratio control strategy for a proton exchange membrane fuel cell (PEMFC) can avoid oxygen starvation and optimize system performance. In this paper, a fuzzy PID control strategy based on granular function (GFPID) was proposed. Meanwhile, a proton exchange membrane fuel cell dynamic model was established on the MATLAB/Simulink platform, including the stack model system and the auxiliary system. In order to avoid oxygen starvation due to the transient variation of load current and optimize the parasitic power of the auxiliary system and the stack voltage, the purpose of optimizing the overall operating condition of the system was finally achieved. Adaptive fuzzy PID (AFPID) control has the technical bottleneck limitation of fuzzy rules explosion. GFPID eliminates fuzzification and defuzzification to solve this phenomenon. The number of fuzzy rules does not affect the precision of GFPID control, which is only related to the fuzzy granular points in the fitted granular response function. The granular function replaces the conventional fuzzy controller to realize the online adjustment of PID parameters. Compared with the conventional PID and AFPID control, the feasibility and superiority of the algorithm based on particle function are verified.

This research presents the application of model predictive control (MPC) to control a proton exchange membrane fuel cell (PEMFC). Firstly, the steady state analysis of PEMFC is considered to select its suitable operating conditions based on cell electrical characteristics. Then, the effect of input parameters on cell voltage and temperature is analyzed to investigate the dynamic behavior of PEMFC that is important for control design. It is found that the cell voltage and cell temperature depend on the inlet molar flow rates and temperature of hydrogen and air, and operating current density. To obtain an efficient control system, the control structure design of the PEMFC is considered to specify a good choice of the controlled and manipulated variables. An analysis of the steady-state relative gain array (RGA) is used for pairing of the controlled and manipulated variables. The result shows that the inlet molar flow rates of hydrogen and air are manipulated variables to regulate the cell temperature and partial pressure of hydrogen, respectively. Finally, a model predictive control (MPC) is developed and designed for controlling the cell temperature and partial pressure of hydrogen. Basically, MPC requires the process model used in its control algorithm. The PEMFC model is known to be complicated and involves uncertain parameters. Thus, an offline robust model predictive control (robust MPC) based on a linear time-varying (LTV) model is proposed for PEMFC control. The simulation results show that the robust MPC shows better control performance than conventional MPC because the robust MPC can guarantee robust stability.

Application of cascade and fuzzy logic based control in a model of a fuel-cell hybrid tramway

Temperature is one of the key factors to ensure reliable and efficient performance of proton exchange membrane fuel cells. Whereas, due to the limited cooling capacity in automotive application, conventional strategies may fail to remove the excessive heat when the cooling actuator saturates. Hence, three temperature control strategies based on current constraint are developed in this study. Firstly, a dynamic thermal model based on energy conservation is presented. Then a duty ratio split control strategy is proposed to calculate the reduced current from the excess of duty ratio of radiator, yet spike behavior occurs. Hence, a current governor control strategy and a constrained model predictive control strategy are derived to trade off the power demand and cooling capacity, where the maximum load current is calculated by current governor in real time and optimized under the physical constraints of duty ratio and current change rate, respectively. The performances of all the strategies are demonstrated. The current governor control strategy is easy to implement with less computational burden. The constrained model predictive control strategy has fast response and can take into account various constraints explicitly. Both of them have satisfying control performances regardless of limited cooling capacity.

Fault tolerance control for proton exchange membrane fuel cell systems

Predicting the impact of ambient temperature on PEM fuel cell cold start-up catalyst degradation with a multi-domain and multi-scale modeling framework

Fuzzy Logic based Control Strategies for Proton Exchange Membrane Fuel Cell System

The objective is to control a web transport system with winder and unwinder for elastic material. A physical modeling of this plant is made based on the general laws of physics. For this type of control problem, it is extremely important to prevent the occurrence of web break or fold by decoupling the web tension and the web velocity. Due to the wide-range variation of the radius and inertia of the rollers the system dynamics change considerably during the winding/unwinding process. Different strategies for web tension control and linear transport velocity control are presented. First, an H/sub /spl infin// robust control strategy which reduces the coupling between tension and velocity, is compared to the decentralized control strategy with proportional integral derivative (PID) controllers commonly used in the industry. Second, an H/sub /spl infin// robust control strategy with varying gains is shown to render the control more robust to the radius variations. Then, a linear parameter varying (LPV) control strategy with smooth scheduling of controllers is synthesized for different operating points and compared to the previous methods. Finally, this LPV control and the H/sub /spl infin// robust control strategy with varying gains are combined to give the best results on an experimental setup, for the rejection of the disturbances introduced by velocity variations and for the robustness to radius and inertia changes.

The fossil fuel depletion and environmental pollution are global challenges. Hydrogen is one of the most abundant elements on earth. Recently, scientists and researchers are investigating water splitting to produce oxy-hydrogen for internal combustion engines. Several studies have been published where hydrogen was used to generate electricity. The proton exchange membrane fuel cell (PEMFC) is an alternative energy resource for future electric vehicles. The reaction of PEMFC includes hydrogen molecules splitting as hydrogen ions and electrons on the anode whereas proton meet with oxygen and electrons and form water and release heat on the cathode. There are several processes involved in heat generation in PEMFC such as resistance in current flow, entropic heat reaction, and irreversibility of the electrochemical reactions. The generated heat in PEMFC is removed through cooling channels. The heat transfer rate depends on thermal properties. The design of the such as polymer electrolyte membrane, catalyst layer, gas diffusion layer, and electrodes have different thermal properties which influence heat transfer. Proper thermal management is critical part of PEMFC operation. Because the efficiency of PEMFC depends on heat loss in-between critical range. In this study, a numerical approach is used to investigate heat transfer performance of a (PEMFC) cooling channel. The heat transfer rate, convective heat transfer coefficient, temperature distribution and pressure drop were evaluated in this work. All these results were carried out on, 0.2, 0.4, 0.6 0.8 and 1 kg/s of mass flow rate of coolant in the PEMFC cooling channel. Ansys Fluent is used for the numerical investigation. The diamond shape extended staggered pattern cooling channel were used in fuel cell for distributed flow. In this study, 2mm transverse pitch whereas 1mm, 1.5 mm and 2 mm longitudinal pitch with diamond shape extended in PEMFC cooling channel are used. However, design of experiments method was used to sort optimum results. The results reveal the extended staggered cooling channel improve heat transfer performance, 2mm and 1.5 mm transverse and longitudinal pitch respectively gave better heat transfer results and slightly higher pressure drops than 2mm pitch. Turbulence kinetic increases with decreasing transverse pitch and flow distribution improved with longitudinal pitch.

Enabling real-time optimization of dynamic processes of proton exchange membrane fuel cell: Data-driven approach with semi-recurrent sliding window method

Proton exchange membrane fuel cells (PEMFCs) are currently a relatively mature type of hydrogen energy device due to their high efficiency and low noise compared to traditional power devices. However, there are still challenges that hinder the large-scale application of PEMFCs. One key challenge lies in the gas supply system, which is a complex, coupled nonlinear system. Therefore, an effective control strategy is essential for the efficient and stable operation of the gas control system. This paper aims to provide a comprehensive and systematic overview of the control strategies for PEMFC anode and cathode supply systems based on an analysis of 182 papers. The review covers modern control theories and optimization algorithms, including their design, objectives, performance, applications, and so on. Additionally, the advantages and disadvantages of these control methods are thoroughly evaluated and summarized.

Review on system mitigation strategies for start-stop degradation of automotive proton exchange membrane fuel cell

Experimental study of the influence of dynamic load cycle and operating parameters on the durability of PEMFC