Controlled Power Technologies shows 48V electric supercharger
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.
About the Author
Mike grew up thinking he would become a mathematician, accidentally started motorcycle racing, got a job writing road tests for a motorcycle magazine while at university, and became a writer. As a travelling photojournalist during his early career, his work was published in a dozen languages across 20+ countries. He went on to edit or manage over 50 print publications, with target audiences ranging from pensioners to plumbers, many different sports, many car and motorcycle magazines, with many more in the fields of communication - narrow subject magazines on topics such as advertising, marketing, visual communications, design, presentation and direct marketing. Then came the internet and Mike managed internet projects for Australia's largest multimedia company, Telstra.com.au (Australia's largest Telco), Seek.com.au (Australia's largest employment site), top100.com.au, hitwise.com, and a dozen other internet start-ups before founding Gizmag in 2002. Now he writes and thinks.
All articles by Mike Hanlon
great idea, guaranteed success I think
I have been advocating using leaf blowers as superchargers for years.
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??
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.
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.
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.
\"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
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?
Crank driven superchargers have no lag. They\'re always spinning, always providing some boost.
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.
re; Gregg Eshelman and Burnerjack
If the blower is set for low end punch it swallows and wastes lots of energy at high RPMs and if adjusted for power at high RPMs provides very little boost at low RPMs.
By using stored power the electric supercharger does not drag on the engine when you want as much power to the tires as possible, while providing optimal boost pressure across the entire RPM range.
Horses for Courses.
Still, Diesel electric is the way, motors with fixed gearing, (or Epicyclics) are more efficient than differentials, long drivetrains, ets as we currently have.
Small Diesel/gas generator for constant load (working at its efficient set point all the time), battery backup for the hard acceleration and hills, there you have the supercharger you always wished you had.. You can even have an (electric/hydralic,exhaust gas, accessory belt and ac clutch, choose your own poison) Supercharger (remember that a turbo charger is just a supercharger driven by an exhaust turbine, the nature of the compressor is irrelevant) if you must in case the little diesel engine needs a bit more poke for that really long hill at 200 MPH which drains the battery, the only time you will ever want to drive up Mount everest at 200 MPH.... (Or Pull a 20 tonne trailer with the Nissan Leaf)
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