Analysis and simulation of a Stop/Start system on an urban bus.

Abstract

This article delves into the application of the Stop/Start microhybrid system in urban buses and its contribution towards energy savings and reduction in CO2 emissions, utilizing ultracapacitors as the power source. The current situation in the automotive industry makes it necessary to look for alternatives to traditional combustion engine applications. The European Union has set strict emission reduction targets under the Euro 6d-TEMP EVAP-ISC regulations. Hybrid and micro-hybrid vehicles, with systems such as Stop/Start, offer economic and environmental advantages by minimizing the running time of the combustion engine. Through partnership with Koneika, a specialist in ultracapacitor-based energy storage, a computer model was constructed for estimating fuel savings and CO2 emissions. The model, built on state machine theory and utilizing Matlab's Simulink tool, simulates the real-time operation and interactions of the bus, offering valuable data on energy savings and greenhouse gas emissions. Studies demonstrate that the Stop/Start system could lower CO2 emissions by 8.1% to 4.5% and fuel consumption by 6% under regular traffic, and up to 11.9% under congested conditions. This reinforces the potential of hybrid or microhybrid technologies, like Stop/Start, in combating increased fuel consumption and emissions in urban environments.