Mild Hybridization Could Boost Automotive Efficiency
Micro and mild hybridization technologies hold promise for improving automotive efficiency, based on comments made by Nick Pascoe, CEO of Controlled Power Technologies, at last month's Automotive Testing Expo and co-located Engine Expo in Novi, MI.
CPT was founded in March 2007 when it acquired products, technology, and facilities from Visteon. Pascoe said CPT's competencies include powertrain development and application, power electronics development, control electronics and software development, and automotive design and validation.
CPT's efforts are driven by the convergence of global standards for fuel economy improvements and CO2 reduction, with the expectation of 27% further reduction in CO2 by 2022. Pascoe said CPT is pursuing mechanical energy recuperation and investigating the feasibility of exhaust gas recuperation. Its products include COBRA, a heavy-duty water-cooled electric supercharger; CPT SpeedStart, an integrated starter motor and generator; and TIGERS, an exhaust-gas energy-recovery turbine.
Pascoe estimated that 12-V micro-hybrid technology could bring about a 4 to 7% reduction in CO2, while a 24- to 130-V mild hybrid system could bring about a 6 to 10% reduction. Hybridization, he said, includes the use of controllable electrical devices such as cooling fans and water pumps.
High-power electrical devices would benefit from higher voltages, but Pascoe noted that going beyond 60 V would impose safety considerations and lead to significant cost increases. He said 48 V provides the ideal compromise for performance and cost. A 48-V standard is evolving in Europe under the auspices of Verband der Automobilindustrie (VDA).
CPT SpeedStart as a 12-V, 3-kW (peak) liquid-cooled belt-driven starter-generator with integrated power and control electronics. The high-torque, fast-response unit provides what Pascoe described as “comfort start-stop” and “driver change of mind” capability, in which a driver decides to accelerate immediately after stopping. Availability is slated for 2015.
Pascoe said CPT SpeedStart has been designed from day one to scale to 48 V, with capacitors, FETs, op amps, and gate drivers all specified to operate at the higher voltage. Specifications for the 48-V version, he said, include 95-Nm breakaway torque, 10-kW generation power, and 10-kW of motoring power available for up to 30 s.
As for the TIGERS exhaust gas recovery system, Pascoe said it targets a 2- to 4-kW rating at 48 V, or 1 kW at 12 V. Development efforts, with funding from the UK Technology Strategy Board VIPER (Vehicle Integrated Powertrain Energy Recovery) project, center on a sensing-system capability study, stator and rotor design for steady-state operation, low-pressure-ratio high-efficiency turbine optimization, and bypass system design and development. CPT is preparing for vehicle installation in February 2013.
For more information, visit CPT's website or view a presentation Pascoe gave at Engine Expo's October 24 Open Technology Forum.
See related blog post, “Expo focuses on automotive test.”
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