Chapter 7
Hybrid Electric Vehicles
7.1 Introduction
Conventional powertrain systems with a single power source based on fossil fuels have dominated vehicle design for the past decade. In recent years, however, fuel economy and pollution concerns have caused hybrid powertrain systems to be seen as one of the alternative approaches to powertrain design. Commercial interest in hybrid vehicle technology has grown at a much more dramatic rate than was predicted a decade ago. Around that time, many industry observers were substantially more optimistic about a major leap from current petroleum-based technology straight to hydrogen, fuel cells and biofuel systems. However, it is now widely accepted that hybrid vehicles will have a significant role to play over the next couple of decades as these other technologies continue to be developed.
The growth in interest in hybrid technology has been driven by increasing concerns about the environment and fuel efficiency savings. Petrol emissions in a car can release harmful gases into the air that can contribute to the ‘greenhouse effect’, damaging the environment's protective ozone layer and causing global warming. In addition, petrol is a limited natural resource with potential supply problems in future. Although hybrid vehicles are still reliant on petrol, they offer the flexibility to enhance the fuel economy and emissions of vehicles without sacrificing vehicle performance factors such as safety, reliability and other conventional vehicle ...
