Patent ID: 7584607

Claim:
In a method for operating an engine drive train having a connectable electrical machine, the electrical machine being drivingly connectable to the engine in whose exhaust gas system an exhaust gas cleaning device is located, the method comprising the steps of outputting or drawing a moment by the electrical machine as a function of an operating state of the exhaust gas cleaning device, impressing the electrical machine moment on a moment of the engine that is demanded by an engine control unit, combining the electrical machine moment with the engine moment resulting in a driver moment for the drive train, and then during a regeneration phase of the exhaust gas cleaning device increasing the temperature of the exhaust gas by maintaining the driver moment and drawing moment by the electrical machine, thereby having a positive effect on the engine emissions and efficiency, and deriving an optimized engine moment from a desired moment demanded by a driver, during a storage phase of nitrogen oxides into the exhaust gas cleaning device, drawing or outputting moment by the electrical machine as a function of a bandwidth around the desired moment, and optimizing a target function dependent at least on the engine efficiency, on the crude NOx emissions and on the NOx storage rate, by specification of the engine moment.