Current electric cars, including the Tesla fleet, are high-voltage systems. The 400V technology requires extra safety measures during crashes and maintenance. A Bavarian startup is developing a new electric motor that is based on the up and coming 48V low voltage technology.
Volabo's Intelligent Stator Cage Drive (ISCAD) gets rid of the inefficient coil found in most of today's electric motors. ISCAD reduces losses in common driving cycles by more than 50% compared to reference drives based on induction machines. Besides being more efficient, the electric drive system is safer as it only requires 48V batteries.
Volabo's Managing Director told I4U News that employees touch the battery poles during presentations to customers to show how safe the system is.
The ISCAD can be built to deliver up to 300kW (400hp). A Tesla Model S 75D has 93 kW (259hp). More efficient, safer, so what is the downside of the Volabo ISCAD technology? The cables between the battery and the motor need to be bigger to accommodate high currents. This is though no issue in electric cars as the motor and the battery are close together.
The startup is kicking off small series production later this year. The company is currently in discussions with car makers about adopting its 48V electric drive solution.
48V ISCAD Motor explained:
Core of the innovative technology is the novel stator of the electric motor: volabo uses a massive stator cage instead of copper coils which are very complicated in manufacturing.
The stator cage made from solid bars and a short-circuit ring replaces wound copper coils. Using ISCAD, a perfect utilization of the motor geometry can be achieved and furthermore, the production in high quantity is easier than for any other wound e-motor.
Every single bar of the stator cage is supplied by a dedicated power electronics unit. The motor induces extra-low voltages due to the low number of turns per “coil” which makes it possible for ISCAD to use low-cost MOSFETs instead of expensive HV IGBTs.
ISCAD eliminates e-motor production complexity and makes the drive intelligent due to new possibilities in logic and control. Thanks to ISCAD Moore’s Law applies to electrical drives now.
The shape of the motor magnetic field can be freely adjusted – smooth fading between different pole pair numbers can be considered as an integration of an electromagnetic gearbox into the motor.
Consequently, the maximum efficiency operating point can be extended to almost the entire torque-speed range. Depending on the driving situation the most suitable “gear” is shifted into. This makes ISCAD extremely efficient, especially at real driving cycles.