Bosch relies on 800-volt technology

Bosch relies on 800-volt technology

“Our 800-volt technology is the next step for more power in the electric drive and shorter charging times,” says Ralf Schmid, the division manager responsible for electrification in the Bosch Powertrain Solutions division. The 800-volt version of the inverter uses silicon carbide (SiC) semiconductors, which increase efficiency and thus also the range. Bosch has increased the power density of the 800-volt version of the electric machine, which reduces the weight and enables a more compact design. The active parts of this drive, i.e. rotor and stator, are being used for the first time by a German premium manufacturer.

In recent years, 400 volts has largely established itself as the industry standard. With the same current strength, twice as much power can now be transmitted with twice the voltage of 800 volts. This further development enables thinner cables, saves installation space, weight and the raw material copper. This makes the inverter more compact and more powerful. With a 400-volt on-board electrical system, a maximum of 250 kilowatts of charging power is currently possible at correspondingly powerful charging stations; with 800 volts, theoretically twice as much. The inverters also use SiC chips, in which carbon atoms are incorporated into the crystal structure of the highly pure silicon. This improves the electrical conductivity of the semiconductors. In addition, 50 percent less energy is lost in the form of heat in power electronics. The SiC chips have even more energy saving potential: the efficiency of the inverters increases to up to 99 percent.

The 800-volt version of the Bosch electric motor, which is now going into series production, scores with a torque of 830 Nm and an output of 460 kilowatts. Thanks to the use of a so-called iPIN winding, i.e. a bar winding, the efficiency, compactness and degree of automation in the production of the motor can be further improved. Expressed in numbers, this means an up to 35 percent higher power density of 60 kilowatts per kilogram when looking at the ratio of power to size of a motor. There is also an excellent torque density of 105 Newton meters per kilogram. At its peak, the Bosch motor achieves an efficiency of up to 98 percent. In the next generation, the electric motor will be equipped with oil cooling. This means that the heat generated in the electric motor can be better dissipated and long-term, high-performance operation can be ensured on long journeys or in commercial vehicles.