Renault’s electric Twizy is trialling a new electric motor configuration with the use of Axial Flux Technology
Real-world efficiency testing of Saietta Group’s AFT 140 electric motor has shown that the technology can dramatically improve the driving range of lightweight electric vehicles (EVs).
The tests, which were led and overseen by independent Dutch engineering consultancy New Electric, saw two Renault Twizy demonstrator vehicles go head-to-head in comparison assessments on public roads in Amsterdam, Netherlands.
The first Twizy was a standard Renault model while the second was upgraded to Saietta’s AFT 140 electric motor. All other systems and components were left untouched meaning that the only difference between the Twizy siblings was the original motor in one test vehicle and the AFT 140 motor in the other EV.
The testing took place across two days in a wide range of weather, temperature and traffic conditions, on varying road surfaces. The engineering team at New Electric concluded that the Saietta AFT 140 Twizy had on average at least a 10% increased efficiency gain over the standard Renault Twizy.
The findings open the way to tremendous opportunities in electrifying a broad range of lightweight vehicles with an advanced drivetrain that is cost effective, offers optimal power and has an enhanced real-world driving range. The ramifications of this will see the likes of motorbikes, mopeds and quadricycles such as the Twizy – used primarily in town and city centres across the world – become zero-emission vehicles that meet all legislative and customer requirements.
Comprehensive test programme
The Saietta AFT 140 Twizy and standard Renault Twizy model were assessed across multiple drive cycle tests in Amsterdam, ensuring a comprehensive test program was completed.
Each Twizy was fitted with a laptop that processed data from the Sevcon controller interface through a CAN-bus connection. This provided the New Electric engineering team with performance data coupled to a time and date of testing ‘stamp’ – information that was later used to synchronise and independently verify the results.
In addition to increasing efficiency by 10% and therefore real-world driving range, the New Electric team also concluded that Saietta’s AFT 140 motor performs exceptionally well during low speeds and constant stop/start conditions, making the technology ideal for inner-city mobility. The is also very adept in converting kinetic energy back into the battery pack during braking.
“We closely assessed the two Twizy EVs and, having completed the programme, I can conclude that the Saietta AFT 140 motor is a good fit for a vehicle such as the Twizy and its potential to create sustainable mobility in congested city centres has few limits,” said Anne Kloppenborg, director at New Electric.
Axial Flux Technology
The fully sealed AFT 140 is the first liquid-cooled axial flux motor from Saietta to go into production. The unique design provides good performance with high torque density at low voltage and is particularly efficient on urban duty cycles.
The AFT 140 motor is compact and very lightweight and has been rigorously designed for high automation in volume production. The motor in the Twizy vehicle is an in-wheel variant of the Axial Flux Technology, demonstrating the full flexibility and modularity of Saietta’s profuct.
“Internally we always knew how our axial flux technology would perform, but for it to be validated by a respected and neutral engineering powerhouse like New Electric is proof to the wider industry of our position in this mobility field. To boost a battery electric vehicle driving range by 10% through simply swapping the electric motor is highly impressive,” says Wicher Kist of Saietta Group.