New generation of mico-mild hybrid vehicles
Low carbon vehicle specialist Controlled Power Technologies (CPT) has completed more than two years of continuous testing to validate its SpeedStart® belt-integrated starter-generator for 1.2 million stop-starts, which is considered the new industry standard that will be required for a new generation of micro-mild hybrid vehicles.
No issues were identified with the technology in any of the recorded test data throughout this extended period of unrelenting stop-start testing followed by a successful teardown and forensic examination of CPT’s award winning motor-generator system.
Nick Pascoe, chief executive of Essex-based CPT said: “We have tested the unit as painstakingly as possible to confirm its capability of frequent stopping and re-starting of an engine way beyond the 150,000 to 300,000 stop-starts currently mandated by vehicle OEMs, but consistent with the continuing trend towards increasing levels of hybridisation and more opportunities for stop events.
“Our compact switched reluctance motor-generator is an advanced yet affordable solution that has been under continuous research and development for more than a decade. This is the confirmation that its durability meets the challenging expectations of the automotive industry – particularly in the US which can now leapfrog European first generation stop-start systems with a starter-generator incorporating increased functionality and proven longevity.”
CPT hybrid product group manager Peter Scanes adds: “A stop-start system has to be specified for near-future requirements including extending vehicle life and increasingly demanding hybridisation strategies, and a typical modern car moreover can easily last 250,000 miles over 15 years.
“More critically, fuel economy targets require reduced stop-inhibits, not just stopping the engine when the driver places the transmission in neutral. Latest implementations allow frequent stop-start events in crawling traffic and future coast-down strategies.
“Switching off the engine, but preparing for immediate re-starts if the driver demands acceleration, will further increase the frequency of stop-starts. We needed therefore to demonstrate as convincingly as possible the near-zero probability of failure during the lifespan of a vehicle as well as the ability to achieve the maximum number of re-starts.
“That’s because one of the most cost effective solutions for low fuel consumption is simply stopping the engine at every single opportunity – even if it’s only for a few seconds every stop counts.”
Developed from the outset for 12, 24 and 48 volt applications, CPT’s powerful SpeedStart system is the world’s first liquid-cooled switched-reluctance motor-generator developed for automotive stop-start. Even at 12 volts the CO2 and fuel economy benefits of this highly efficient starter-generator combined with high current electrical energy regeneration can be as much as 20 per cent.
CPT’s technology development partner is Nidec Corporation of Japan, one of the world’s leading suppliers of electric motors.
• PHOTOGRAPH: CPT SpeedStart units are also undergoing accelerated testing in an environmental durability test rig to simulate hostile under-hood temperatures cycling between -25 and +125⁰C air temperature and between -25 and +110⁰C engine coolant temperature. SpeedStart development and test engineer Craig Letts pictured in the test chamber is assisted by test technician Peter Wayman.