Modelling and Testing of a Turbo-generator System for Exhaust Gas Energy Recovery

In order to meet increasingly arduous CO2 emission targets, various 'more-electric' technologies are emerging. However, their adoption will result in a significant increase in the peak electrical load. An attractive solution to meeting the electrical power requirement is to generate electrical energy from the exhaust gas by means of a turbo-generator system, consisting of a turbine-driven, high-speed switched reluctance generator and an energy storage/power buffer. An energy management strategy is implemented to control the highly transient power flows to the various loads and the energy storage device, which may be either a battery or a super-capacitor bank, or a combination of both. Such a system represents a significant improvement over current vehicle electrical architectures in terms of electrical power availability. This paper describes the development and testing of a prototype exhaust gas energy recovery system, operating at a nominal voltage of 14.6 V.