Experimental comparative analysis of the combined Stop & Start and alternator with mechanical decoupling strategies

There is a clear concern about air pollution on the planet. Measures to reduce CO₂ emissions in the Earth's atmosphere were taken to minimize the possibility of global warming. In the context, many countries have created laws and incentive programs that encourage an automotive industry to develop innovative technologies to increase the energy efficiency of their vehicles, thereby reducing fuel consumption and consequently reducing CO₂ emissions. Often technologies are applied in combination so that there is an increase in energy efficiency of the vehicle. The objective of this work is to present an experimental evaluation of the energy consumption and reduction of CO₂ with a combined application of the Stop & Start measures and mechanical decoupling of the alternator. The new alternator with mechanical and consequent electrical decoupling, consists of a pulley integrated to an electromagnetic clutch. The decoupling is performed according to the internal combustion engine operating conditions. This solution allows the complete unloading of the crankshaft in relation to the inertia and the electromagnetic field of the alternator. To measure the reduction of fuel consumption and carbon dioxide, a vehicle with the possibility of operation as two strategies to test in the cycles FTP75 + Highway. Each technology was tested separately and in combination, demonstrating that the combined application allows a considerable reduction of energy and CO₂ emission. A strategy of the mechanical undocking of the alternator allowed a greater reduction than the effect of the isolated Stop & Start strategy.