International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-8 Issue-9, July 2019 2368 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: I8813078919/19©BEIESP DOI:10.35940/ijitee.I8813.078919 Analysis of Characteristics of Pem Fuel Cell . Abstract: In present scenario non conventional energy sources plays an important role in various applications. This paper focuses on study of Proton Exchange Membrane (PEM) fuel cell and verification of its polarization characteristics by using “Matlab Simulation”. Index Terms: PEMFC, Fuel Cell, Matlab, Polarization Characteristics I. INTRODUCTION The essential requirement for the growth of economy globally and progress of the human beings is safe, clean, reliable and low cost energy supply. Over last couple of years in all developed and under-developing countries, electrical energy has become inevitable requirement. In future the energy and electricity demand will become tremendous and it has become critical to develop clean and sustainable energy sources. In a few years traditional mineral energy sources such as fossil fuels will be depleted and results serious problems on economic growth. Hence renewable energy sources play a vital role in energy power generation [1] - [3]. Fuel cell is a environmentally sound renewable energy source which reduces the reliance on fossil fuel. Fuel cell which is a electrochemical device uses air & hydrogen as its fuel. Because of zero emission potential, low temperature, high efficiency, long stack life and high power density Proton Exchange Membrane (PEM) fuel cells are more advantageous compared to other fuel cells. Fuel cell finds various applications in different fields. The input for the fuel cell is hydrogen and output is dc power at the stack. The three primary sources from which losses of fuel cells are originated are a) ohmic polarization, b) activation polarization, and c) concentration (mass transport) polarization curve which is shown in Fig.1 [4].In Fig.1 it is observed that there is nearly linear decrease in the cell voltage when there is increase in the load current, Hence there is a need to regulate the output voltage to obtain the desired value. Revised Manuscript Received on July 09, 2019 M.Malathi, Department of Electrical and Electronics Engineering, NIE Institute of Technology, Mysore, India. Dr Usha Surendra, Department of Electrical and Electronics Engineering, Christ University, Kengeri Campus, Bangalore, India Fig1 Cell Voltage Vs Current Density There is a need to control the parameters like humidity, pressure and temperature to get the polarization curve at a steady level [4]. II. PEM FUEL CELL’S POLARIZATION CHARACTERISTCS The polarization characteristic of Fuel Cell is a curve which is obtained by plotting cell voltage versus current density. The primary sources from which the losses occurred are “Ohmic, Activation and Concentration losses.” A. Activation losses The “activation losses” are non linear with current. Typically with increase in load current initially there will be a sudden drop in “open circuit EMF due to “activation losses”. These losses occur due to chemical process has not started initially. “Activation losses” occurs only when current density and temperature of the fuel cell is low [4]. V con V ohmic V act NERNST E FC V     Where, “E Nernst ” represents “thermodynamic potential” and “reversible voltage”; “V act ” represents“voltage drop” due to “the activation of the anode and cathode”, “V ohmic ” represents “ohmic voltage” and “V con ” represents “voltage drop due to reduction in concentration of the reactants gases or, alternatively, from the transport of mass of oxygen and hydrogen”. There is a need to take into account one more “voltage drop” related to “internal current and/or fuel crossover” even at no-load operation using a fixed current density[5]. B. Activation voltage drop M.Malathi, Usha Surendra