An Energy-Efficient Regenerative Braking System

Abstract

This paper proposes a novel regenerative braking scheme for electric vehicle driven by brushless dc motor and uses a new control technique to utilize regenerative braking energy successfully. The drawbacks of electric vehicle are that long travelling, distance covered between two charging stations, and less accelerating power during uphill driving. The fuel efficiency and driving range of electric vehicle can be improved by regenerative braking energy. To provide smooth brake, the electric brake distribution is obtained through fuzzy logic controller. To control motoring and braking in electric vehicle, a few bidirectional converters are utilized to incorporate batteries and super-capacitors. The braking action in regeneration is much exaggerated because of discontinuous input current at motor end and regenerative braking failure at lower back-EMF. The switching of power flow direction from one to another instantaneously is difficult for conventional converters. A bi-directional buck-boost converter is proposed in this paper to extract maximum power even at lower speed.

Keywords: bidirectional buck-boost converter, EV (electric vehicle), fuzzy logic controller (FLC), hybrid energy storage system (HESS), regenerative braking energy (RBE)