Optimal Control Strategy for PEM Hybrid Electric Vehicle using Matlab Simulink

Abstract

The conventional fossil fuels are being replaced by alternate energy sources very fast. This is mainly due to the limited resources left in the Nature and the polluting characteristic of fossil fuel. Only thirty additional years are left for the supply of fossil fuels. The extreme climate change is largely attributed to automotive fossil fuel burning. The advent of pure Electric vehicles has resulted in reduction of harmful greenhouse gas emissions. It addresses the answer to the concerns of oil resource depletion, air pollution and climate changes. The benefit of using electric power in automotive sector is immense. However, the outcome of hybrid EVs can surpass pure EVs due to its capability of charging on the go, hence no extra charging time. In absence of any moving parts in a fuel cell, the maintenance and noise are also minimal. PEM fuel cell is a most eligible power source having reduced emissions and high efficiency characteristics. The efficiency of hybrid vehicle is a result of charging effectiveness. Control Strategy plays an important role in conservation and elevating energy whenever required. These are the energy power banks to optimize battery sizing and minimize losses. This paper explains a control strategy to enhance efficiency of FCHV system along with reduction of hydrogen consumption. This is achieved by maximizing fuel cell efficiency by balancing the power split between battery and fuel cell. The rule based strategy results in maximizing fuel cell system efficiency by sustaining the state of charge (SOC) of the battery. The SOC is aimed to be kept around a value which can address extremely low charge and high charge condition of the battery. At the same time, load on fuel cell is switched in a manner so as not to have a sudden ascent or descent of power, which helps in preventing the terminal deterioration in the fuel cell. Hence, PEMFC works as Range extender to the powertrain system and charges the battery while the vehicle is moving. The fuel cell efficiency and durability is maximized by balancing the power split between battery and fuel cell. The rule based strategy is applied in order to maximize fuel cell system efficiency and sustaining the state of charge (SOC) of the battery.