Analysis of a Drive System in a Fuel Cell and Battery powered Electric Vehicle

In this paper the design and the operation of the drive system in a Fuel Cell Electric Vehicle (FCEV) is presented. The system consists of a Proton Exchange Membrane Fuel Cell (PEMFC) stack, an interleaved boost converter, battery pack connected via a bidirectional buck-boost converter and a brushless DC motor (BLDC) driven by a three phase inverter. A basic analysis of each component of the investigated system is presented. The main objective of this paper is to manage the energy transfer from the PEMFC stack to the DC bus based on wide high efficiency range. A battery pack is used for reducing the size of the stack and thus the cost, with by which regenerative braking is also achieved. In order to testify the nonlinear V-I characteristic curve of the PEMFC system experiments have been carried out. The performance of the overall system in steady state is studied via simulation in MATLAB/SIMULINK software. Two operating scenarios have been investigated. In the first, PEMFC stack and battery pack provide maximum power to the BLDC motor, while in the second, regenerative braking is accomplished via the bidirectional buck-boost converter to the battery pack by changing the control logic of the three phase inverter. Experiments have been carried out to validate the performance of the system at full load at steady state. KeywordsPEM Fuel Cells, interleaved boost converter, drive system of electric vehicle, regenerative braking.