Application of a Variable Drive to Supercharger & amp; Turbo Compounder Applications

The role of turbocompound in the era of emissions reduction

“…Much research into turbocompound over the past decade has focused on the development of CVT-based turbocompound systems (Figure 1b), where the separate power turbine is discarded and a variable transmission is used to link the turbocharger turbine to the crankshaft [7,8]. The turbocharger turbine now serves the function of both the "boost providing" turbine as well as the "power providing" turbine.…”

“…Add in the recent developments in advanced turbocompound systems -using CVT (continuously variable transmission, Fig. 1b) technology to improve performance of the turbocompound system throughout the engine speed and load range [7,8] and one might think that turbocompound is finally poised for more widespread market penetration. However, an additional trend must be considered when assessing the likely role of turbocompound in future high efficiency diesel engine development, and that is the trend in emission compliance technology.…”

Coupling of a KERS Powertrain and a 4 Litre Gasoline Engine for Improved Fuel Economy in a Full Size Car

“…Regenerative braking is probably the best option to improve the fuel economy of passenger cars, light and heavy duty trucks and busses covering driving cycles characterized by frequent accelerations and decelerations [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Recovering the kinetic energy otherwise lost during braking may indeed significantly reduce the amount of energy to be supplied by the engine to reaccelerate the vehicle.…”

“…These four energy transformations reduce the overall level of efficiency. If the motor/generator operates at 80% efficiency under peak load, in and out, and the battery charges and discharges at 75% efficiency at high power, the overall efficiency over a full regenerative cycle is only 36% [12][13][14].…”

“…The ideal solution is to avoid all four of the efficiency reducing transformations from one form of energy to another by keeping the vehicle's energy in the same form as when the vehicle starts braking when the vehicle is back up to speed. This can be done using high-speed flywheels [12][13][14][15], popular in space and uninterruptible power supplies for computer systems, but relatively novel in ground vehicles.…”