Remember CPT’s VTES electric supercharger? It was installed onto a 1.2 litre turbo engine to complement the turbo and results were pretty impressive. The VTES has been positioned as a motor assist system similar to the Honda IMA system.
In the Honda IMA system, an electric motor positioned between the combustion engine and the gearbox provides a boost of power when needed. The VTES electric supercharger is presumably lighter than an electric motor and can provide a similar boost of torque at low engine RPMs as it is able to kick in really fast – 0 to 700,000rpm in less than a third of a second. Like the electric motor, VTES is also powered by battery.
The VTES component is already being trialed as a piece of the puzzle in various systems currently being designed by automotive parts companies. Ricardo is currently using the VTES in a project they’ve christened HyBoost. But CPT has a little project of its own and VTES works as part of a system called RegEnBoost.
RegEnBoost combines three devices developed by CPT – the VTES electric supercharger, a liquid-cooled integrated starter generator (start-stop system) called SpeedStart, and a turbo-generator called TIGERS. TIGERS is somewhat like a turbocharger except it isn’t. It uses exhaust gas to generate electricity instead of providing boost, so it’s more of a dynamo in a way.
The three devices are integrated into a system which also incorporates a DC to DC converter and a lead acid battery optimised for fast energy storage and release. This same system also provides the regular 12V needed by the car’s electrical systems, but also delivers short bursts of power to the 2kW VTES supercharger when extra acceleration is needed. It also powers the SpeedStart starter when the engine is needed to restart. Conversely, SpeedStart can recharge the battery during deceleration. So the battery can be charged by two sources – SpeedStart and the TIGERS exhaust generator.
CPT claims that a 1.0 litre car with RegEnBoost can emit less than 100g/km of CO2 on average yet offer the same performance and in-gear acceleration of a 2.0 litre normally aspirated engine when needed – translated into horsepower and torque that’s about 130 to 150 horses and about 200Nm of torque, pretty decent from a 1.0 litre engine. CPT says RegEnBoost can easily be scaled up to support engines of up to 3.5 litres.