UK consortium to develop new drivetrain technology for hybrid & electric vehicles to reduce dependency on rare earth metals
21 September 2011
UK-based motor control specialist Sevcon Ltd (earlier post) is leading a collaborative project that includes Cummins Generator Technologies and Newcastle University’s Power Electronics and Drives Research Group to develop a new type of electric traction drive for use in hybrid and pure electric vehicles that will use steel to replace the rare earth magnets used in motors.
The project being undertaken by the Sevcon-led group will work on the development of a novel “no rare earth metals” electric drive system for EVs using advanced high torque density switched reluctance motor technology.
The group has secured more than £500,000 (US$782,000) in matched funding from the from the government-backed Technology Strategy Board (TSB) and the Department for Business Innovation and Skills (BIS) in the latest round of national support for work on new low carbon vehicle technologies.
The partners anticipate that the project should be ready for volume production within four years.
The advanced design being developed by the team also seeks to replace traditional electronic control systems with new technology based on advanced power electronics. As well as providing sufficient power, the new generation system will also be designed to be both cost-competitive and suitable for high volume manufacture.
This is an exciting, cutting edge project in a market sector that has great potential. We are already very active in the low carbon vehicle sector and the performance capabilities of our advance technology motor controllers are ideal for this sort of application. We are delighted to be bringing our automotive drivetrain engineering expertise to this project.
—Dr. Peter Barrass, Sevcon Vice President of Engineering
The UK Technology Strategy Board and Department for Business Innovation and Skills (BIS) have jointly agreed to invest £10 million (US$16 million) in grants to sixteen collaborative research and development projects that focus on achieving significant cuts in CO2 emissions for vehicle-centric technologies in low carbon vehicles. (Earlier post.)
AC propulsion is already using copper conductor induction motors for its automobile motors. Many diesel electric locomotives as well as straight electric locomotives use induction motors. Even with the high price of silver, there might be an economic value in the use of silver conductors in large induction motor rotors.
The UK has been at the front of switched reluctance motors with its SR drives company. Switched reluctance motors are already very light, efficient and low cost compared to all motors. Switched reluctance motors can be made for very high speeds with known designs and also some proprietary ones. SR motors can operate at very high temperatures where permanent destruction of rare earth magnets would happen. This means that such motors can be designed with very high, short period overload capabilities. Also some SR designs allows reduced power operation with coil failures.
A coil short in a permanent magnet design can burn up the coil and perhaps the rest of the motor before the rotor stops, but there is no way of burning up a coil in a SR motor with energy from the moving rotor and no active power switches.
After a SR design is made the motors can be built cheaply in mass production, so even the smallest motors can benefit from the cheap computerized control available. Some seldom used motors in automobiles, could still use ceramic magnets and common motor brushes, but motors used frequently can all now be SR motors and save energy. Even electric drives for induction motors can get more complicated to build than SR motor electronic drive circuits.
Model aircraft motors and their drives should soon be converted to SR operation to save weight and cost and energy.
SR motors can also be used as generators with the proper timing on the identical switches. One of the first experimental electric locomotives in the UK was built with a SR motor and mechanical contacts over a century ago. ..HG..
Posted by: Henry Gibson | 22 September 2011 at 01:12 AM
There is no permanent destruction of rare earth magnets with high temperatures.. they can be recycled back to life again.
This is just another gov grant program to industry/academia.. and thats not bad, it may be even pay off in future tax revenue, there are much worse ways for governments to waste money.
How are the NHV issues with SR motors?, is there an issue?
Posted by: Herm | 25 September 2011 at 02:24 AM