|Liquid cooled version of TIGERS. Click to enlarge.|
The UK-based micro-hybrid specialist Controlled Power Technologies (CPT) will contribute its TIGERS (turbo-generator integrated gas energy recovery system) technology (earlier post) to the recently announced Vehicle Integrated Powertrain Energy Recovery (VIPER) project (earlier post).
The VIPER project will build on CPT’s involvement in the Ricardo-led HyBoost program (earlier post), which is similarly part funded by the UK Technology Strategy Board (TSB). The new VIPER project aims to show how a reduction in CO2 emissions of 4.5% can be achieved over a broad range of vehicles in part by optimizing the control of heat energy from conventional gasoline and diesel engines. The project is being led by Jaguar Land Rover. Other consortium members include Ford, IAV, BP, University of Nottingham and Imperial College London.
CPT’s turbo-generator integrated gas energy recovery system employs the same switched reluctance technology as its production-ready VTES electric supercharging and SpeedStart stop-start systems. The company reckons on five years of development to bring this latest application of its technology to a similar state of production readiness; the TSB anticipates that VIPER technologies could be applied to the majority of new vehicles before the turn of the decade.
The VIPER project builds on our exhaust gas energy recovery work already underway for the HyBoost program. HyBoost also includes our VTES electric supercharger. There’s enormous synergy in the integration of these and other micro-hybrid technologies such as SpeedStart; the mild electrification of gasoline and diesel engines can produce highly efficient vehicles able to achieve significant fuel savings with CO2 emissions of less than 95 g/km for the average family saloon.—CPT engineering director Guy Morris
The recent availability of low-cost low-voltage power electronic devices has significantly advanced the development of micro-hybrid technologies such as VTES and SpeedStart, CPT says. CPT has engineered compact and highly scalable series production solutions that were previously unavailable and is able to manufacture using industry standard processes with minimal capital investment and tooling. Because of the number of programs it now has under development and the increased level of interest from car makers, CPT is currently seeking to recruit additional engineers and a technical sales manager.
VTES. CPT’s VTES electric supercharger achieves a high boost pressure in a short space of time, significantly increasing an engine’s air charge density over the critical first 10 combustion cycles of a low speed transient, says Mark Criddle, CPT’s senior engineering manager for VTES.
Fitted with a low inertia compressor, the supercharger accelerates from idle to its maximum speed of 70,000rpm in less than a third of a second enabling a turbocharged engine to achieve full load torque within one second at very low engine speeds.—Mark Criddle
This fast dynamic response and rapid air boosting enables the system to react instantly to high transient load conditions, delivering up to 25 kW (33 bhp) of additional power at the crankshaft. This compensates for turbo lag and is more cost-effective than integrating a 25 kW electric motor into the powertrain since only a 12-volt system is required, CPT notes.
The combination of a highly dynamic electric supercharger, which CPT recommends in series with a conventional exhaust driven turbocharger, makes it relatively easy to optimize the overall response of the system, compared to other air charging methods. The VTES technology can also help reduce soot and particulate emissions from diesel engines, creating an opportunity to reduce the size and cost of a diesel particulate filter (DPF).
CPT’s core competencies include low-voltage power electronics, advanced control software and the application of 12-24 volt electrical machines to vehicle powertrains. Having concentrated on 12-volt micro-hybrid applications for passenger cars and light commercial vehicles, the company has started looking at the application of its technology to 24-volt systems initially for small trucks and buses.