High Power Pemfc System Dynamic Modeling Based On Oer

The proton exchange membrane fuel cell (PEMFC) is a new energy, it has a significant impact on society in the21st century, and is a very efficient and environment friendly energy device. In recent years, fuel cell vehicles, hybrid vehicles and fuel cell locomotives use it as ideal energy to research and development. Current research on the PEMFC focuses on the steady-state characteristics, the research of the dynamic characteristics is rare.The project group of our laboratory find out OER(Oxygen Excess Ratio) is an important indicator to measure the power generation performance of the fuel cell system in the process of research. So in this paper focuses on the dynamic characteristics of PEMFC and OER of the other related issues. The main work and conclusions as follows.1. On the basis of the working principle of the fuel cell and PEMFC, This paper provided a detailed introduction of the fuel cell output characteristics and OER. It describes a fuel cell polarization and the effect of power generation performance of the fuel cell system by OER. OER is an important indicator to measure the power generation performance of the fuel cell system.2. This paper builds a comprehensive dynamic mode of PEMFC, it includes the voltage dynamic model, hydrogen and air supply dynamic model, thermal dynamic model. It provided a detailed analysis of the impact on the system output from the dynamic model. A simulation and analysis of the dynamic response of the comprehensive dynamic model of PEMFC polarization curve, the output voltage, power and efficiency in different operating conditions. To raise the temperature, flow of the reaction gas and the film humidity can help to improve the battery performance, the influence on the battery performance from the cathodic oxygen flow is greater than the anode hydrogen flow.3. To build a fuel cell engine model, it constituted by air compressor model and the stack model. Simulating the air compressor model, it analyzes the effect of the air compressor model from the environment temperature and atmospheric pressure. When the altitude of work environment increase, the air compressor power consumption will be increased, the engine of fuel cell system efficiency will be reduced.Simulating the fuel cell engine model, it gets the OER characteristic curve. Analyzing of the fuel cell system output power and efficiency characteristics. When the stack temperature change, comparing of the change in the OER characteristic curve. Increasing temperature can help to improve the efficiency of the system, but the air compressor power consumption will be increased, and the electric power efficiency of system will be reduced.4. Finally, experimenting in the NEXA1.2kW system, it verifies the correctness of the steady-state model, it also verifies the feasibility of the dynamic model. Therefore, the model of this paper is able to clearly reflect the dynamic performance of the PEMFC.