DESIGN AND ANALYSIS OF HYBRID ELECTRIC VEHICLE [HEV]

Abstract

Hybrid Vehicle fuel economy and drivability performance are very sensitive to the “Energy Management”
controller that regulates power flow among the various energy sources and sinks. Many methods have been
proposed for designing such controllers. Most analytical studies evaluate closed-loop performance on
government test cycles. A hybrid vehicle structure comprising fuel cell/battery and a DC electrical machine has
been proposed, in which an intelligent controller is to perform power management and regenerative braking
tasks. Instead of a gasoline engine, an electric machine fulfills the power demand from the vehicle during
driving and braking modes. In addition, regenerative braking is possible in the proposed structure. The fuel cell
is connected to a battery (DC bus) via a DC/DC converter which can control the fuel cell power/current with a
switching strategy. Duty cycle of the DC/DC converter is computed by the driving controller and applied with a
certain switching frequency. Along with the power demand, braking pedal displacement, and the battery state of
charge act as controlling signals, which allow the power management controller to perform pertinent analysis
for power sharing decision between both the power sources. A threshold zone has been considered for braking
pedal, according to which a regenerative torque is produced by the electrical machine. Finally, the simulation
results have been considered from different point of views and evaluated, which shows a tenable achievement.
Particularly, a series of driving manoeuvres were applied to the vehicle, and the results show that the proposed
structure has a promising performance as a civic automobile with zero emissions.