Lightweight Electric/Hybrid Vehicle Design

Abstract

The hybrid vehicle is considered to be a short-term remedy to the pollution problem. The hybrid-drive concept appears in many forms depending on the mix of energy sources and propulsion systems used on the vehicle. It has two forms, parallel and series hybrid. A neat description of the problems of hybrid-drive vehicles has come out of the results of the 3 year HYZEM research program undertaken by European manufacturers. BMW researchers have shown the possibility of challenging the fuel consumption levels of conventional cars with parallel hybrid levels, by using map-controlled drive management. To implement the driving modes of either hybrid, electric or IC engine the CPU breaks down the operating strategy into tasks processed parallel to one another, to control and monitor engine, motor, battery, and electric clutch. The mode task determines which traction condition is appropriate, balancing the inputs from the power sources; the performance/output task controls power flow within the total system; the battery task controls battery charging. Because of the system complexities of hybrid-drive vehicles, computer techniques have been developed to optimize the operating strategies. This chapter describes some of the case studies involving hybrid technology. Until the flywheel storage or fuel cells systems are available the best option is to use a hybrid driveline consisting of a small battery.