Automotive

Controlled Power Technologies shows 48V electric supercharger

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The 16th Annual Supercharging conference was held last week at the Technical University of Dresden in Germany where many interesting new developments in the critically important field of forced induction were shown.

Most motor vehicles only use maximum power for a small fraction of their time on the road, and with downsizing of engines now standard practice for the auto industry, supercharging is an ideal way of providing that power boost from a small engine.

We've written several times in the past about the promise of Controlled Power Technologies (CPT), its 12 volt electric supercharger and its exhaust gas energy recovery systems, and the latest news is that it has a 48 volt version which uses 7 kW of electrical power and delivers an extra six to ten times that power at the crankshaft - ideal for small engines that require extra grunt for overtaking and steep hills.

Based on CPT's Variable Torque Enhancement System (VTES), the air cooled supercharger will rev instantaneously (within a third of a second) to 70,000rpm, overcoming the major drawback of "lag" associated with crankshaft driven superchargers and exhaust gas driven turbochargers.

The new CPT electric supercharger uses switched reluctance motor technology and is well placed to exploit the proposed 48 volt electrical architecture announced earlier this year by European vehicle manufacturers. Switched reluctance motors are highly efficient and avoid the use of permanent magnets and rare earth materials.

CPT is hoping that vehicle manufacturers will see its transient electric boosting as a more efficient alternative to the mechanical supercharging and/or twin turbo-charging systems currently used in micro hybrid vehicles.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. "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 power-trains 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 7 kW of stored electrical power to deliver not less than six times that at the crankshaft. In other words adding a useful 42 kW boost for low speed overtaking and hill climbs. Depending on the turbocharged engine system optimization the boost could be as much as much as 70 kW or 10 times the instantaneous power extracted from the batteries or super-capacitors."

"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."

For more info, see Controlled Power Technologies web site.

12 comments
robinyatesuk2003
great idea, guaranteed success I think
Slowburn
I have been advocating using leaf blowers as superchargers for years.
Facebook User
We only use maximum power for a fraction of the time but we are considering carting round 3 extra batteries permanently for these odd occasions??
drakesword
Ok so the advantage of a turbocharger is to take wasted exhaust energy and put it into the intake. With everyone wanting to go green how does this help? It will need a separate power source which could be a battery or boost converter who knows. The power used to drive this will be coming from the electrical system without a doubt which already has its inefficiencies. Cool idea but I don\'t think it will fit into modern green trends.
Slowburn
re; Clive Edmead - October 4, 2011 @ 06:13 pm PDT There are other ways of going from 12 to 48volts than three extra lead acid batteries. I would either use an inverter and a transformer and draw a heavy amp load from the battery, put a switchable output controller on the alternator, maybe combine them or use batteries from cordless tools for the power supply.
Slowburn
re; drakesword - October 4, 2011 @ 06:26 pm PDT Aside from all the mechanical difficulties associated with turbochargers. If you want lots of people to buy a tiny engined car you need to make it perform like the big normally aspirated big engined car they are used to. the Volt might be a masterpiece of engineering but to most people even after the tax payers subsidize the price it is an over priced under performing tinny little econobox. Personally I would prefer a Ford Pinto.
Garth Hoyman
\"The new CPT electric supercharger uses switched reluctance motor technology and is well placed to exploit the proposed 48 volt electrical architecture announced earlier this year by European vehicle manufacturers. Switched reluctance motors are highly efficient and avoid the use of permanent magnets and rare earth materials.\" apparently everyone commenting missed the above
Burnerjack
Umm, why not use the accessory belt drive? you are converting mechanical energy into electrical energy, then back to mechanical energy for enhanced chemical/thermal energy to mechanical energy conversion. Huh? This is a breakthrough? I suppose making it easier to place under the hood is a plus, but 48vdc when the parent machine is 12vdc? Gee I dunno guys... I think maybe a real small supercharged diesel driving an appropriate sized alternator charging a buffering battery pack which feeds a traction motor set might do the trick. Too simple?
Gregg Eshelman
Crank driven superchargers have no lag. They\'re always spinning, always providing some boost.
Expanded Viewpoint
Or... behind door number 3, how about just using an electric clutch like for the A/C compressor? Hook up a switch like GMs used for the TH400 trans to make a downshift when needed, and when you get down to about 3/4 of the way to WOT (or adjust it wherever you want it to come on at), the boost kicks in and awaaaay you go! An A/C clutch can handle 5Hp with the small amount of surface area they currently have, so if you were to increase that area (quite easily done BTW), you could handle at least 10 Hp to spin the compressor. I love it when a plan comes together! Or... behind door number 4, tap some of the hydraulic fluid off of the power steering pump and use that to spray against a vane pump and spin it that way. A solenoid valve could open up the high side line when boost is needed. Randy