CPT is helping to pioneer several 12-48 volt micro-to-mild hybrid developments.
European automakers are rethinking the need for 12-volt cars. There is a move toward 48 volts, little noted in the U.S. media, which has significant implications for a new generation of potentially cost-effective mild or semi-mild hybrid vehicles. A proposed 48-volt standard could be a major factor for enabling the required motor-generator efficiency and power levels to make a practical hybrid at a much lower cost than current production models that use much higher voltages.
A company in the United Kingdom has shown an exhaust energy regeneration system that can return 2-4 Kw from an engine’s hot exhaust gases. Controlled Power Technologies, a Ford and Visteon spinoff, claims that compared to the energy recovered from brake regeneration used on hybrids this is the equivalent of recycling 40-75% of the braking energy generated during a New European Driving Cycle test.
This technology is only the one piece of an efficiency puzzle that is now seeing European automakers developing mild hybrids where the car’s electrical system is 48 volts instead of 12 volts. A 48-volt system appears to be a good compromise for performance and cost in the development of a new generation of affordable, fuel-efficient cars. However, the automotive road is littered with engineering ideas that never made it to production, as an aborted 42 volt movement decades ago proves.
At the 15th Automobil-Elektronik Congress in Ludwigsburg last year, five German automakers – Audi, BMW, Daimler, Porsche and Volkswagen – jointly announced their decision to push for the rapid implementation of 48-volt systems. Ford in Europe is also exploring the technology. A huge potential market is possible because of pending global CO2 emission targets. The auto industry has about a decade to achieve another 30% reduction by 2022.
“The convergence of global standards for fuel economy and CO2 emissions means that the industry will need to embrace exhaust gas energy recuperation as well as kinetic energy recovery by electro-mechanical means as the next major step,” said Nick Pascoe chief executive at Controlled Power Technologies during a recent interview with AutoInformed.
Pascoe said that auto industry estimates of the additional cost to a buyer to achieve the required 30% reduction in CO2 emissions are ~$1,500 for a family sized car.
SpeedStart is a belt-driven starter/motor and generator with its control and power electronics fully integrated into the liquid cooled device.
Audi has already built and calibrated a 3.0 V6 TDI with an electric bi-turbo. It is a combination of a conventional gas-driven turbocharger with a secondary electrically-driven compressor. Audi is also looking at a 48-volt stop/start system. When the internal combustion engine is switched off, the restart comes via a 48-volt electric motor that is located in the belt drive. While the engine is switched off, energy is supplied via a 48-volt battery.
CPT is helping to pioneer several 12-48 volt micro-to-mild hybrid applications through the development of electric superchargers; a belt-driven starter/motor and generator with its control and power electronics fully integrated into the liquid cooled device dubbed SpeedStart; and so called Tigers technologies – a water-cooled turbine integrated gas energy recovery system.
Increasing the voltage beyond 60 volts requires much greater safety systems to avoid electrocution leading to a significant increase in cost. The specification for 48 volts is still evolving, and there may yet be more than one, but there is “real pressure from global automakers to conclude the specification as quickly as possible,” said Pascoe.
With the support of the Advanced Lead-Acid Battery Consortium (ALABC) based in North Carolina, CPT will have its own 48-volt technology demonstrator running early next year deploying what is claimed to be a complementary breakthrough with lead-carbon batteries.
“Automakers have a broad palette of hybrid technology options,” said Pascoe. “Some however are more expensive than others. Mild and full hybrid vehicles including plug-in hybrids, for example, operating between 200 and 600 volts, incur significant additional development and product costs to the automaker, which then have to be passed on to the consumer or absorbed by the OEM; hence the need for governments to subsidize electric vehicles. Consequently such hybrid and electric vehicles are unaffordable for most motorists even with government subsidies.”
