Dr. Peter Harrop, the chairman of IDTechEx, has produced a report on the next electric vehicles which will get ultra lightweight motors.
The new IDTechEx Research report is called “Electric Motors for Electric Vehicles: Land, Water, Air 2019-2029”, and it explains the new emphasis on a power-to-weight ratio with good efficiency in electric vehicles.
The motor power-to-weight ratio
Harrop explains the importance of the motor power-to-weight ratio in electric vehicles: “In electric aircraft, the motor power-to-weight ratio is paramount for endurance, the main constraint on sales. You cannot lug ever more battery weight to get a range. Indeed, better motors mean less battery in land, water or air vehicle.”
Permanent magnet motors
Harrop continued: “5 kW/kg in most e-aircraft is achieved by Siemens or YASA using variants of permanent magnet motor. The huge tethered drone of Makani is backed by Shell as well as Alphabet now. Its eight YASA motors pull it upwards then generate 800kW at 10kW/kg. Multicopters and fixed-wing aircraft trend up to 18 such motors.”
“Equipmake’s spoke magnet PM motor has a route to 15 kW/kg. Four will be in the 2020 Ariel Hypercar yet a Brazilian bus will use two because it is smaller and cheaper to make. Even cheap magnets give 25% less magnet per torque. It is good for the car, bus, bike, boat, plane – anything needing high performance, compactness, efficiency. CEO Ian Foley portrays this ultra-compact, high-performance PM motor as the most power and torque-dense with huge cooling advantage.”
Axial flux PM motors
He added: “Axial Flux PM motors from AVID and others assessed in the report are looking good, with claims of a 10% increase in efficiency and wide application. Belgium start-up Magnax scopes three markets for its newly-designed axial flux PM motors in 2019-20 – mainstream electric vehicles, motorcycles, and aviation. Dyson brings motor superlatives from domestic electrics to EVs.”
The Tesla 3
Harrop concludes in the report: “The Tesla 3 car excels partly because of its variant on the switched reluctance motor giving extra range. Motor excellence in on-road vehicles is increasingly important because the new norm is two to six motors per bus or truck and two to four in a large car. Electric Motors for Electric Vehicles: Land, Water, Air 2019-2029 appraises many other routes to high power density motors often by newcomers and explains the focus of the motor company acquisition frenzy and who is next.”