CPT Developing Powerful 48 Volt Electric Supercharger For Micro Mild Hybrids
The low carbon vehicle specialist Controlled Power Technologies is developing a 48 volt version of its electric supercharger based on its variable torque enhancement system known as VTES. The more powerful higher voltage variant will support moves by European vehicle manufacturers announced earlier this year to introduce 48 volt passenger vehicle power networks to help meet the requirement for lower fuel consumption and CO2 emissions.CPT
At 48 volts a VTES electric supercharger will efficiently transform 7kW of battery power into a highly boosted charge of air for downsized gasoline and diesel engines. Unlike crankshaft driven superchargers and exhaust gas driven turbochargers, an electric supercharger is mechanically decoupled from the engine, which means it can deliver the air almost instantaneously into the engine – spinning up to 70,000rpm in less than a third of a second.
“Even with the higher transmission gearing adopted by manufacturers to reduce CO2 emissions and particularly at the lowest engine revs, the instant additional torque when the driver needs to accelerate these smaller powertrains from low engine speeds is already very beneficial at 12 volts,” says CPT’s engineering director and chief technical officer Guy Morris. “Electric supercharging at 48 volts extends that envelope of torque enhancement. It’s an efficient way of using 7kW of stored electrical power to deliver not less than six times that at the crankshaft. In other words adding a useful 42kW boost for low speed overtaking and hill climbs. Depending on the turbocharged engine system optimisation the boost could be as much as much as 70kW or 10 times the instantaneous power extracted from the batteries or supercapacitors.”
CPT foresees a new generation of micro mild hybrid vehicles with radically downsized engines featuring transient electric boosting as a more effective hybrid alternative to the mechanical supercharging and/or twin turbo-charging systems in use today.
“The torque response of these future VTES equipped vehicles will be equivalent to the best mass market vehicles on the road today,” says Morris. “There will be no torque deficit or other tradeoffs from essential engine downsizing and higher gearing, which now dominates the development of internal combustion engines. If anything their low speed performance will be even better, while still delivering very significant fuel economy benefits and CO2 reduction.”
Commenting on additional applications, CPT’s senior manager for VTES, Mark Criddle adds: “We’ve also been responding to customer enquiries from vehicle manufacturers for some while now interested in applying VTES technology to diesel engines, both to help with the control of NOx and particulates, and for the regeneration of off-highway engine diesel particulate filters.”
Morris and Criddle are attending the annual Supercharging conference in Dresden this week to discuss these latest developments with vehicle manufacturers making their annual pilgrimage to discuss new supercharging and turbocharging concepts for future powertrains. The industry’s main annual conference on the subject has long recognised the importance of air boosting as a key technology for the development of internal combustion engines.
CPT is exhibiting at the conference where it will discuss its modular 12, 24 and 48 volt technical solutions focused on the innovative application of switched reluctance electric motor technology and low voltage power electronics. Switched reluctance motors have yet to be adopted by the automotive industry for high volume mass production and low voltage power electronics have only recently become commercially viable. Switched reluctance motors are highly efficient and avoid the use of permanent magnets and rare earth materials. CPT technology development is primarily focused in the 10 to 50 volt range, where modest voltage increases can offer significant efficiency improvements.
CPT’s production ready VTES technology has already been incorporated as a 12 volt system in its ‘low cost’ ‘low consumption’ ‘low carbon’ LC Super Hybrid technology demonstrator. The company has commissioned AVL to build the demonstrator, which is currently undergoing final shake-down trials in Austria in readiness for evaluation by vehicle manufacturers. Following this initial assessment by carmakers, the vehicle will then be re-built with a 48 volt electrical system. The project is being supported and funded by the Advanced Lead Acid Battery Consortium (ALABC).
CPT is already on record saying that if adopted as a global industry specification, 48 volt power networks would facilitate the development of standardised high volume and highly affordable enhanced lead acid battery modules. It would also offer a potential mass market opportunity for high end lithium-ion based energy storage solutions, of a similarly standardised modular configuration. Modules of 48 volt standard configuration could form the building blocks for lower volume electric vehicles, where battery system costs are currently such a dominant constraint to vehicle affordability.
The 16th Supercharging event is a high level engineering conference organised by Prof. Dr.-Ing. Hans Zellbeck of the automotive technology institute at the TechnicalUniversity of Dresden. Companies sending speakers include ABB, BorgWarner, Caterpillar, Daimler, Deutz, Ford, Honeywell, IAV, MAN and Voith. Further details at http://lvm.iad.vkw.tu-dresden.de/index3.php?SECTION=ATK2011&LNG=en
CPT is an up-and-coming, award winning, high tech company specialising in cost-effective CO2 reduction measures for the global automotive industry. Its work also includes thermal energy recuperation considered by many to be the next and perhaps final energy recovery challenge for the internal combustion engine. Engineering competencies include low voltage power electronics, advanced control software and the application of low voltage electrical machines to vehicle powertrains including full hybrids with range extenders. The company was established in 2007 as a management buy-in funded by venture capital initially to acquire advanced powertrain technologies from Visteon Corporation and its technology development partner Emerson Corporation. CPT comes with a highly experienced team of automotive engineers and is backed by Turquoise Associates and other prominent investors specialising in the energy and environmental sectors. Further information on CPT is available at www.cpowert.com.