Ultrakompakter Brems-Chopper

Project Targets

© Fraunhofer IISB

Development of an ultra-compact, high-temperature capable brake chopper that can be mechatronically integrated into a drive unit.


Very high pulse energy absorption capacity

Ambient temperature of up to 125°C

Trigger signal and temperature monitoring

Extremely fast current rise times (µsec to rated current)

Galvanic insulation for interface and cooling

Short Description

With nonregenerative inverters, brake choppers limit the voltage of the DC link when the connected electric motor is actively braked.

The task was to integrate a brake chopper for a DC link voltage of over 1kV and several hundred amps of short-circuit current into a circular segment shaped space.


With a sophisticated 3D CAD design, a high geometric filling factor could be achieved and the extreme installation space requirements could be met. The three-dimensional power busbar allows current rise speeds of several hundred amperes per microsecond. The brake chopper can absorb braking energy of up to 4kJ.

The chopper supplies its logic from the vehicle electrical system and has a short-circuit-proof diagnostic interface.

Project Partners


Project Duration