Lithium Iron phosphate (LiFePO4) battery has obtained extensive attention of researchers for its high energy density, little contamination and ready availability. In this paper, different numbers of RC branches in the equivalent Thevenin circuit model are explored by comparing accuracy of curve fitting with in-house experimental data. Besides, battery system with 6 cells of second order equivalent circuit is modeled using Matlab/Simscape. A multirate strong tracking extended filter (MRSTEKF) is proposed by introducing the multirate control strategy and lifting technology into strong tracking extended Kalman filter (STEKF) to improve tracking stability and estimation precision of state of charge (SOC). Root mean square error (RMSE) is exploited to evaluate the performance of the algorithms of extended Kalman filter (EKF), STEKF and MRSTEKF. Simulation results demonstrate that the proposed MRSTEKF is faster than EKF and STEKF by 55.34% and 49.51%, and is more precise by 52.66% and 33.88%.

A heat transfer model of PEMFC is developed that captures dynamic behavior for control purposes in this paper. According to the law of conservation of energy, by analyzing in detail the heat source, considering the heat of electrochemistry, activation polarization heat and the heat loss of air forced convection etc., the dynamic heat model of PEMFC is established. Among all influential factors of fuel cell temperature, current density is one of the most important influence factors. Finally, by comparing the response results temperature with the current density changes between simulation and experiments, the results s are consistent. The model in this article has an important guiding significance for the design of fuel cell. For example, the working temperature of fuel cell can keep up stability by controlling cooling medium flow rate etc.

This paper presents the characteristic study of a clean hybrid power supply system combining proton exchange membrane fuel cell (PEMFC) as the main power source and ultracapacitor (UC) as the energy storage unit. Unlike the conventional fuel-cell hybrid system with power conditioning unit, the study investigated the electrical characteristic of the PEMFC and UC hybrid system without dc/dc converter. As a platform to evaluate the proposed system, the fuel-cell-based electric bicycle is implemented. The platform consists of PEMFC stack, metal hydride, thermal balance system, UC, dc motor, system control and data logging unit, as well as user interface. The test results showed that the proposed architecture is functional and leads to good results. By road testing, it was verified that the PEMFC can provide the rated power to the load and that the UC can deliver the power at system startup and the peak power if needed. The road testing results showed that the design objectives are fulfilled.

This paper presents a dynamic multi-input multi-output (MIMO) model of PEM fuel cells and a nonlinear control approach appropriate for this model based on exact linearization. Since large deviations of pressures between anode and cathode gases can cause severe membrane damage in fuel cells, it is necessary to design a corresponding controller so that the deviation can be kept as small as possible during the load variations, in the meantime, the purpose to prolong the stack lifetime of the PEM fuel cells can also be achieved. The PEM fuel cell model, nonlinear control by exact linearization and generic model control (GMC) are described and combined as a system in Matlab/Simulink environment and the results show that the system is available to simulate the transient performance of fuel cells and it is effective on fuel cell membrane protection.

In order to investigate the output characteristic of a proton exchange membrane fuel cell (PEMFC) based on the electrical empirical model, a novel dynamic model of the PEMFC has been developed with MATLAB/Simulink, which is distinct from the models that have been published previously. By using a fuel cell test system of the Fuel Cell Application Centre (FAC) at Temasek Polytechnic, the transient electrical responses of PEMFC were conducted and analyzed under various operating conditions. A good match is found between simulation results and experimental data. The comprehensive results of simulation manifested that the model is effective and operational. This model will be very useful to optimize the structure design, improve the operation performance, and develop the real-time control system of PEMFC.

In order to obtain the optimal operating conditions for the maximum output power of proton exchange membrane fuel cell (PEMFC), a PEMFC mechanism model was developed with Matlab. Adaptive focusing particle swarm optimization (AFPSO) which had preferable ability of global search and search rate was proposed to estimate the parameters in this model. The comparison between experimental results and simulation results demonstrates that AFPSO can make the simulation results fitted the experiment data with higher precision and has manifest superiority for estimating the model parameters. Furthermore, AFPSO was used to search the optimal operating conditions of PEMFC. Compared with the experimental results, the validity of AFPSO was further proved. Hence AFPSO achieves significant effect for optimizing the model parameters and improving the output performance of PEMFC.

Adaptive focusing particle swarm optimization (AFPSO) based on the balance characteristic between global search and local search of particle swarm optimization(PSO) was an adaptive swarm intelligence optimization algorithm with preferable ability of global search and search rate.According to the modeling principle of proton exchange membrane fuel cell (PEMFC), AFPSO was proposed to research a set of optimized parameters in the mechanism model.The comprehensive comparison between simulation results and experimental results demonstrated that AFPSO could make the simulation results fitted the experiment data with higher precision and have manifest superiority for estimating the model parameters. Therefore, AFPSO makes important effect for improving the output performance of PEMFC mechanism model and becomes a new effective tool in the fields of model parameters optimization.

This paper presents a clean power system combining fuel cell and ultracapacitor. The fuel cell, which acts as the primary power source, is used for the continuous load requirement. The ultracapacitor, which acts as the secondary power source, is used for the peak load requirement. A controller also is designed to determine and assign the power between the fuel cell, ultracapacitor and motor..and this clean power system is applied to an electric scooter. The result of experimentation shows that the system is very effective and steady.

In order to investigate the output characteristic of proton exchange membrane fuel cell (PEMFC) based on the electrical empirical, a novel dynamic model of PEMFC has been developed with Matlab/Simulink, which is distinct from the models have previously been published. By using a fuel cell test system in Fuel Cell Application Centre in Temasek Polytechnic, the transient electrical response of PEMFC was conducted and analyzed under various operating conditions. A good match is found between simulation results and experimental data. The comprehensive results of simulation manifested that the model is effective and operational. This model will be very useful to optimize the structure design, improve the operation performance, and develop the real-time control system of PEMFC.

The use of fuel cell technology as a backup power source for the uninterruptible power supply (UPS) requires quick response to sudden load change. However, slow dynamic behavior of a PEM fuel cell, compared to the typical power conditioner and load, limits the fuel cell rapid transient response to load change. To increase the fuel cell response to load change, the energy storage such as battery, micro turbine, photovoltaic and super-capacitors are conventionally installed in the system thus increasing in its size and cost. In this work, the PEM fuel cell transient behaviors in the cool-start, hot-start and load change were investigated by using in-house running control software and high precise oscilloscope. The effects of fuel cell structure (area of flow field, cell number and materials used in MEA) and operation conditions (pressure, temperature etc.) were also studied. The electrical response results from experimental curves indicate that the transient behavior of fuel cell stack is highly impacted by the fuel cell structure, operating conditions and the strategy of gas input into the fuel cell. The better understanding of the electrical response of PEM fuel cell would be helpful to the design of a fuel cell and its system with high efficiency and compact structure.

A solar panel is a device that converts light into electricity. Solar electric energy is being used on a larger scale because of environmental concerns and to some extent falling prices of solar cells. Manufacturers of solar electric equipment need solar panels for testing their product such as characteristics of the solar cells and maximum power tracker circuit. A programmable solar simulator can replace all these solar panels that are being used for testing and development purpose of solar electric equipment. In this article, a system with an embedded microcontroller is discussed. It can either control the solar panel simulator individually, or communicate with a host that can do simulation by RS232, so it can be a portable and effective system to simulate the solar panel