UK’s low carbon vehicle technology specialist, Controlled Power Technologies (CPT), will demonstrate its solution for CO2 reduction in a micro-mild hybrid technology demonstrator being shown at the Cenex LCV2012 event this week.
CPT has achieved its low-cost breakthrough to deliver electric hybridization at the relatively safe voltages of 12-48 volts, which is complemented by lead-carbon batteries. The LC Super Hybrid micro-mild concept retains a conventional albeit downsized petrol engine, which the industry can produce at low cost, augmented through mild electrification by deploying a number of highly controllable modular products including a stop-start system known as SpeedStart.
The production-ready technology offers the potential of a mass market, petrol-powered, large family saloon with great drivability, performance equivalent to a 2-litere car and excellent 50mpg (5.6 liters/100 km) fuel economy achieved at substantially lower cost than an equivalent diesel model or plug-in hybrid. The low-voltage technology enables aggressive yet near-term downsizing and down-speeding of existing engine families.
The LC Super Hybrid demonstrator has, according to the company, helped to define a whole new class of low-cost micro-mild hybrid vehicles. The car has been developed in cooperation with the Advanced Lead-Acid Battery Consortium, an international research group based in the U.S.
The vehicle includes production-ready technology recently sold by CPT to the leading French tier 1 supplier Valeo, thereby becoming the first global automotive component manufacturer to offer carmakers a range of electric superchargers. Other international companies involved are powertrain developer and systems integrator AVL Schrick based in Austria and Germany, drive belt specialist Mubea also from Germany, and Provector, a leading expert in battery management systems, based near Cambridge in the UK.
Based on a series production 1.4-liter turbocharged VW Passat TSI model – generally considered an industry benchmark for fuel economy in this size of vehicle – the LC Super Hybrid is providing carmakers with real world validation of this development.
The technologies comprise an electric supercharger, next generation belt-integrated starter generator with an advanced belt tensioning system, new PbC lead-carbon batteries which avoid the need for super-capacitors, and higher gear ratios to reduce engine speed.
Recalibration of the engine increases power from 122 to 142PS and torque from 200 to 275Nm. This power and torque is more comparable with VW’s bigger 1.8-liter TSI gasoline engine, which delivers 160PS and 250Nm, and the engine output of the LC Super Hybrid is generally equivalent to vehicles in the 2-liter class.
Despite the enhanced gasoline engine performance the vehicle achieves near diesel levels of fuel economy, but with substantially lower production costs.
The impressive performance and excellent fuel economy are underscored by the acceleration figures and results measured on the standard European drive cycle. The LC Super Hybrid delivers CO2 emissions of less than 130g/km compared with 140g/km for the baseline Passat 1.4-liter TSI, which is already best in class, and an even more significant reduction when compared with 160g/km for the 1.8-liter TSI model. This represents a reduction in CO2 emissions of 8 and 23 percent respectively.
Similarly, the fuel economy of 50mpg (5.6 liters/100 km) represents a significant 11 and 24 per cent improvement respectively when compared with 46mpg (6.2 liters/100 km) for the 1.4- liter TSI and 6.9 liters/100 km (41mpg) for the 1.8-liter TSI also measured over the NEDC European drive cycle.
This notable reduction in CO2 emissions and fuel consumption has to be seen in the context of the performance and drivability of the technology demonstrator. In 6th gear, which is taller even than the gearing in the baseline vehicle, the 50 to 75mph (80 to 120 kph) top gear acceleration is reduced by 3.5 seconds from 16.0 to 12.5 seconds. Similarly, the 0-62 mph) (0-100 kph)time is reduced by 2.5 seconds from 11.1 to 8.7 seconds compared with the 1.4-liter TSI and achieves virtually the same acceleration (8.5 seconds) as the 1.8-liter TSI model.
The demonstrator embraces low voltage switched reluctance (SR) motor-generators, which are not currently employed by the automotive industry in mass production. The motors are of simple robust construction using steel, aluminum and copper and avoid the use of increasingly expensive rare earth materials required for permanent magnet motors. The SR technology is licensed from Nidec Corporation of Japan.
The micro-mild hybrid technology builds on previous work by CPT carried out with AVL, who were commissioned to build the LC Super Hybrid and handled the systems integration. The demonstrator incorporates CPT’s SpeedStart stop-start system, which includes intelligent torque and current control with enhanced stop-start capabilities.
The SpeedStart system is the world’s most powerful belt-integrated starter generator (B-ISG) to operate at 12 volts, and the first and only system based on the highly controllable switched reluctance motor-generator technology, which resolves all stop-start issues including the notorious driver ‘change of mind’ problem. The Mubea belt tensioner system facilitates rapid reversals of the motor-generator, solves many packaging issues and virtually halves the belt loads, reducing friction of the front end accessory drive system while significantly improving belt durability.
The lead-carbon battery design (supplied by Exide Technologies) provides a cost-effective solution, fully realizing SpeedStart’s potential for high power generation, including regenerative braking, fast restart and torque smoothing