Method for controlling a hybrid driveline

Abstract

A method is provided to control a hybrid powertrain to achieve a desired engine speed in a combustion engine, said powertrain comprising: a gearbox with input and output shafts with the combustion engine connected to the input shaft; a first planetary gear connected to the input shaft and a first main shaft; a second planetary gear connected to the first planetary gear and a second main shaft; first and second electrical machines respectfully connected to the first and second planetary gears; first gear pair connected with the first main shaft; and second gear pair connected with the second main shaft. The method comprises a) ensuring that two rotatable components in the first planetary gear are connected; b) ensuring that all rotatable components in the second planetary gear are disconnected; c) ensuring that a gear is engaged in the first gear pair, d) ensuring that the second gear pair is disconnected; e) controlling the second electrical machine so that a desired torque is achieved in the output shaft; f) controlling the combustion engine to a desired engine speed; and g) controlling the first electrical machine so that a desired total power consumption for the first and the second electrical machines is achieved.