John Deere has leapt forward in the electric autonomous tractor race with its first cable-powered vehicle. CPM reports.
Farmers can now use their own energy when powering agricultural machinery, with John Deere’s new GridCON tractor. Electrically powered by cables, it can plug into an on-site renewable energy grid, generating up to 400hp but without the weight of a high-powered tractor.
The prototype weighs 8.5t – the same as a conventional John Deere 6195R tractor but with twice as much power. Research engineers are aiming to reduce the weight further by at least one tonne.
John Deere’s first fully electric powered tractor – the SESAM (Sustainable Energy Supply for Agricultural Machinery) – was presented in 2016. The GridCON tractor is very different in that it is doesn’t feature a cab and requires no batteries under the bonnet.
Continuous power transfer
GridCON utilises a cabled connection from the border of the field to the machine, which transfers power continuously at over 300kW. A 100kW electric motor powers the IVT transmission, and there is an additional outlet for implements powered by a 200kW electric motor.
On the tractor, 1000m of cable is attached via a drum, although the length can be extended if required. A robot arm guides the cable as it is fed out and reeled in, to keep the operation friction free and at low load. An intelligent guidance system is also used to prevent the tractor running into or over the cable.
Farmers can control the tractor manually using a remote control or leave it to follow preset rows autonomously at up to 12mph (20kph).
A power supply of 2.5kV AC is required, and the GridCON tractor uses a 700V DC bus for electric power distribution with total drivetrain efficiency in the region of 85%.
Besides the favourable power to weight ratio, the tractor offers noiseless and emission-free operation, and delivers around 50% lower machine and operating costs.