voestalpine electrical steel for mild hybrids

voestalpine electrical steel is used in many electric vehicle components. Here we explain how this relates to the 48V power supply in mild hybrid vehicles, and the contribution electrical steel makes to reducing CO2 emissions.

Introducing the 48V power supply gives rise to a “light” version of hybrid electric vehicles. These cars are known as Mild Hybrid Electric Vehicles, or MHEV. They differ primarily from vehicles with conventional combustion engines in having an additional, highly-efficient electric motor which supplies strong assisting torque and functions as a generator to powerfully charge the 48V battery. And where electromobility demands efficiency, isovac® electrical steel from voestalpine is the answer.

Hybrid motor

Efficient electrical steel made by voestalpine

Using high efficiency motor and generator components in the vehicle’s 48V power supply is a natural choice, because the advantages offered by a higher voltage are paid for in the form of heavier components. Increasing efficiency allows their weight to be reduced. High torque, paired with minimal power loss when converting electricity into motion energy, can only be achieved using a motor core constructed from the best magnetically-soft material.

“isovac® allows us to produce the right electrical steel for all forms of electromobility,” emphasizes Christian Schreiner, Director of Sales Electrical Industry at voestalpine Stahl GmbH. With its optimized magnetic and mechanical properties, isovac® is a top product for the electromobility megatrend.

Electrical steel isovac® in an electric motor

Reduce emissions

In an MHEV the combustion engine and electric motor can be used in parallel, although pure electric driving tends to be uncommon. The electric motor/generator is usually integrated into the drive architecture via a transmission belt (e.g., Audi), or between the motor and transmission (e.g., Mercedes). The higher voltage permits the use of additional power units, such as the e-turbo.Most importantly, however, it forms the basis for key “economy functions,” such as start-stop, gliding, power-assisted steering, and air conditioning while the combustion engine is turned off. Recuperation also contributes by feeding in additional energy to recharge the battery in the 48V network; this is electricity available to the driver which does not otherwise need to be generated by the driving motor. Converting to a 48V onboard power supply should bring reductions in fuel consumption of up to twelve percent.

Important 48V terms:

• Start-stop function
  Turning off and almost immediate restarting of the combustion engine, e.g., at traffic lights.
• Gliding function
  Automatic turning off and restarting of the combustion engine when driving downhill; the vehicle power supply ensures that the power-assisted steering and brake servo continue to function while gliding.
• Stationary air conditioning
  Air conditioning system operates even when vehicle is at a standstill and the combustion engine has been turned off.
• E-turbo
  Electric compressor which, for example, closes the “turbo gap” when the combustion engine is running at low engine speeds in order to increase engine output efficiency.
• Recuperation
  Recovery of electrical energy released by the braking process which is then fed to the vehicle batteries.

More information: www.voestlapine.com/isovac