Development of a Braking Energy Regeneration System for City Buses

Abstract

<div class="htmlview paragraph">In order to improve the fuel economy of city buses, which start and stop frequently, a system has been developed that stores braking energy in a hydraulic accumulator and uses the energy when the vehicle is in its start and acceleration modes.</div> <div class="htmlview paragraph">Through microcomputer control of the entire power train and energy storage system, the following goals are achieved: <ol class="list nostyle"> <li class="list-item"> <span class="li-label">1.</span> <div class="htmlview paragraph">By applying currently available transmission technologies to the conventional power train system, all component functions are controlled so as to minimize the losses over the driving cycle.</div></li> <li class="list-item"> <span class="li-label">2.</span> <div class="htmlview paragraph">By applying a regenerative braking system, as much vehicle kinetic energy as possible is recovered and stored, and,</div></li> <li class="list-item"> <span class="li-label">3.</span> <div class="htmlview paragraph">The energy stored is used so as to achieve maximum overall efficiency.</div></li></ol></div> <div class="htmlview paragraph">A test vehicle functioning in city conditions achieved a 30% fuel economy gain.</div> <div class="htmlview paragraph">Other advantages of this system are that brake wear is greatly reduced and clutch life is significantly extended since the vehicle can start in motion using only hydraulic energy.</div>