MTU at work on engines with electrically assisted turbocharging

To provide the turbocharger with electrical assistance, a permanent magnet is installed upstream of the compressor wheel (1) and the electrical winding (2) is integrated into the casing of the compressor. The special feature of this arrangement is the large gap between the magnet and winding. This ensures that there is no aerodynamic impact on the charger and also that existing chargers can be adapted easily to enable them to make use of this technology

SEPTEMBER 25, 2017 — By 2021, MTU plans to start offer engines with electrically-assisted turbocharging.

“Electrically-assisted charging is a milestone on the way to the hybridizing of the engine. Using this technology, it will be possible for us to develop agile, low-consumption engines,” said Dr. Johannes Kech, Director of Development Turbocharging & Fluid Systems at MTU.

MTU parent Rolls-Royce has acquired the exclusive rights of use of patented electrically assisted charging technology, developed by G+L innotec GmbH, Laupheim, Germany, for off-highway combustion engines in the power range above 450 kW. MTU and G+L innotec will complete the next stages of development on the basis of a close partnership.

The system comprises an electric drive combined with a traditional turbocharger developed and manufactured by MTU. It enables the turbocharger to be accelerated electrically and the charge pressure built up earlier.

The system allows for a faster build up of charge pressure under operating conditions in which the required energy would normally be insufficient. Using the technology developed by G+L innotec, MTU will be able to increase the acceleration capability of marine engines and the load-switching capacity of generator drives. In addition it will also be possible to reduce the engine’s fuel consumption and emissions in a variety of different applications. Due to the increased load switching capability, emergency standby gensets will be able to deliver their full output faster than was previously the case.

The technology is well suited to both diesel and gas engines.

Operating principle of the electric drive from G + L innotec

To provide the turbocharger with electrical assistance, a permanent magnet is installed upstream of the compressor wheel and the electrical winding is integrated into the casing of the compressor. With this arrangement, the air drawn in by the compressor is not obstructed and at the same time the electrical components are cooled by the air.

The special feature of this arrangement is the large gap between the magnet and winding. This so-called media gap motor requires specially designed power electronics. This ensures that there is no aerodynamic impact on the charger and also that existing chargers can be adapted easily to enable them to make use of this technology.

In a development collaboration agreement with G+L innotec, MTU has equipped turbochargers with this electric drive and has carried out component tests to determine its possible potential. In the next stage, the two partner companies will prepare the new products for series production.