Sevcon were mentioned in an article about Griffon Hoverwork’s innovative, battery-free diesel-electric drive of the latest Electric & Hybrid Marine Technology International issue.
Three years ago, Griffon Hoverwork was exploring ways of reducing the amount of ballast, usually in the form of water or fuel, that a hovercraft needed to carry and continually reposition in order to maintain trim. The design team based in Southampton, on the UK’s south coast, hit upon the idea of siting one of the two 1.6-liter Ford Tiger car diesel engines at the front of the new 995ED hovercraft, rather than having both at the rear in the conventional layout. To achieve this in a craft capable of operating on either engine, or both, the drive had to be transferred from the diesel motor at the front to the propellers at the rear. GHL’s engineers had some experience of electric and hybrid drives from previous jobs and decided to bring an automotive-style diesel-electric setup into play, with lightweight electric motors providing the drive to the 995ED’s propellers.
The diesel-electric drive was developed purely to help balance the craft, but is in itself an innovative hybrid system because it does not feature batteries. “There are few, if any, other diesel-electric systems of this size [60-100kW] that have no batteries,” notes Mark Downer (Chief Engineer). “Batteries are usually required to smooth out fluctuations in the bus voltage going to the motor. For the amount of power we wanted, batteries were heavy and very expensive. Instead, working with our motor controller supplier, Sevcon, we developed control software that enabled us to use a motor as a generator 100% of the time. The resulting battery-free system is very lightweight.”
To read the full article on page 22 click here.
To view the Griffon Hoverwork website click here.