Aeristech of Birmingham has secured £500,000 to develop its electromechanical turbocharger.....
In a conventional turbocharger, a turbine in the engine's exhaust system extracts power, and delivers it to a compressor through a mechanical shaft. The compressor forces air into the engine....
"Turbochargers are fitted to make an engine more powerful by using the energy from exhaust gases, which would otherwise be lost, to raise the pressure of air entering the engine. This also increases engine efficiency and materially enhances fuel consumption," said Aeristech. "However, conventional turbochargers only assist the engine when sufficient exhaust gas energy is available. Any mismatch between what the engine needs and what the turbocharger produces is known as turbo lag."....
The answer, according to Aeristech, is to replace the mechanical coupling shaft with a generator, motor, and energy storage device.
These allow the motor to drive the compressor immediately acceleration is required using power from the energy storage device.
Energy is replaced seconds later by the exhaust-driven generator.
Complete, original article: http://www.electronicsweekly.com/Articles/2010/06/23/48902/Electric-turbocharger-firm-gets-163500000.htm