RETARDER BRAKE SYSTEM OF A VEHICLE COMBINATION

Retarder braking system (10) of a vehicle combination (16) consisting of an agricultural tractor (12) and an electrically driven trailer (14), comprising a drive train (18) with an internal combustion engine (20), a vehicle transmission (22) connected downstream of the internal combustion engine (20), a mechanical drive axle (28) of the agricultural tractor (12) connected to a first transmission output (24) of the vehicle transmission (22), a first electrical motor-generator unit (38) connected to a second transmission output (26), and an electrical drive axle (50) associated with the trailer (14), which is drivable by means of a second electrical motor-generator unit (48), wherein the two electrical motor-generator units (38, 48) are electrically connected to one another via a direct current intermediate circuit (62). In a retarder mode of operation, the second electrical motor-generator unit (48) is operated in generator mode and the first electrical motor-generator unit (38) is operated in motor mode, so that at least a portion of a gross retarder power demanded at the electrical drive axle (50) is dissipatively eliminated as loss power within the drive train (18).