Mission R: Innovative e-motors, high-end battery and 900 volts
“It's indescribable; the immediate surge of power from the two electric motors is something you simply have to experience for yourself," says Timo Bernhard, discussing the drive system of the Mission R.
The Mission R is on a par with the performance level of the Porsche 911 GT3 Cup. The power output remains constant over the duration of the race, so there is no thermally induced de-rating – a major advantage of the electric motors with direct oil cooling developed by Porsche. The electric motor on the front axle produces up to 320 kW (435 PS) in race mode.
In qualifying mode, the all-wheel-drive car has a peak system output of more than 800 kW (1,088 PS). The continuous system power in race mode is 500 kW (680 PS). The lightweight electric racing car, which tips the scales at around 1,500 kg, accelerates from zero to 100 km/h in less than 2.5 seconds.
The capacity of the battery, which also incorporates high-end cells and direct oil cooling, is designed for sprint racing.
Highly efficient e-motors with direct oil cooling
In 2018, a team of Porsche engineers and technicians in Zuffenhausen and Weissach began to develop extremely powerful and highly efficient electric motors. The most important innovation of these permanently excited synchronous machines (PESMs) is the direct oil cooling of the stator, which enables very high peak and continuous power output levels to be achieved, in addition to delivering a very high level of efficiency. While in conventional electrical machines the cooling fluid flows through a jacket outside the stator, in the case of direct cooling, the oil flows directly along the copper windings. In addition, the slots in the stator can be made smaller, which leads to greater efficiency in real driving cycles.
High voltage: Porsche electric motors explained
An optimisation algorithm was used to determine the optimum shape and position of the magnets in the rotor. During production, the magnets are inserted into the rotor laminations and extrusion-coated with plastic. As a result, they do not move, despite high centrifugal forces, and the balancing quality of the rotor remains stable. At the same time, the plastic helps to dissipate the heat generated in the magnets.
High-end battery and 900-volt technology
Here again, direct oil cooling offers tremendous thermal advantages – because it makes use of the entire surface of the cells, a large amount of heat can be transported from the battery into the cooling system.
Based on the 800-volt technology of the three-time Le Mans winner, the 919 Hybrid, the Porsche Taycan was the first car to enter production using this system voltage instead of the 400 volts normally used in electric cars. In the Mission R, Porsche is raising the bar a notch higher again with a voltage rating of more than 900 volts. Using 900-volt technology will result in further improvements in continuous power, weight and charging time. At DC fast charging stations, the Mission R can be charged from five to 80 per cent SoC (State of Charge) within approximately 15 minutes. The maximum charging capacity is 350 kW.
Special high-voltage alert system for the pit crew
As a matter of principle, the high-voltage safety concept of the Mission R meets the same high standards of safety as those required for series production vehicles. If the LEDs light up green, the Mission R is high-voltage safe. If the LEDs are red, on the other hand, only high-voltage trained personnel should approach the vehicle.
Sep 07, 2021 at 04:34