One for the road

Graduate engineers from Imperial College London’s Racing Green Endurance (RGE) team have raced their battery-powered Radical SRZero car 26,000 km along the Pan-American Highway to prove that all-electric vehicles are more than a fad.

The eye-catching Radical SRZero electric car is claimed to be the only road-legal car with no mechanical differential. In its place, the car uses a 54kWh lithium-ion phosphate battery pack placed along each wing of the car to power two motors mounted on its rear wheels.

’As simple as it sounds, this was not a trivial design task, partly because we had to deploy a 600V power bus to optimise the efficiency of the electrical drive system, with the result that two bespoke inverters had to be developed to drive the AC motors,’ said Alec de Zegher, chief software architect of RGE.

Not only that, but the motors also had to be custom wound to ensure that they worked at 95 per cent or greater efficiency at the 40-65mph average cruising speed of the car. Since no battery-charging management system existed to ensure that the batteries were being charged optimally, the team also developed their own hardware for that task too.