A hybrid system for propulsion of a vehicle comprising an internal combustion engine; the hybrid system comprising a supercharging system for the internal combustion engine, wherein, the hybrid system comprises: a charging device with a turbine connected to a compressor via a compressor shaft, the compressor having a high speed shaft; a planetary gear coupled between the high speed shaft and an electric motor/generator; a clutch unit; and a power transmission for connecting a crank shaft of the combustion engine to the electric motor/generator, via the clutch unit; wherein the hybrid system further comprises a system control unit configured to operate the hybrid system in different operating modes according to a control algorithm based on one, or a plurality of, input parameters representative of operational properties of the hybrid system, characterized in that the plurality of operating modes comprises: an operating mode A where the electrical motor drives auxiliary loads of the internal combustion engine; an operating mode B where the electric motor starts, or stops, the internal combustion engine; an operating mode C where the electric motor propels the vehicle; and an operating mode D where brake energy from retardation of the vehicle is regenerated to electrical energy; wherein the clutch unit is a first clutch unit and wherein the hybrid system further comprises a second clutch unit; wherein the planetary gear is coupled to the electric motor/generator via the second clutch unit, wherein the hybrid system further comprises: a third clutch unit for connecting the power transmission to the crank shaft of the combustion engine, wherein the system control unit comprises a mode controlling subsystem arranged to control the hybrid system based on the selected operating mode and the input parameters according to a mode control algorithm, wherein the mode control algorithm comprises engaging or disengaging the first, second and third clutch units (18a, 18b, 18c), operating the electric motor in drive mode or generate mode based on the selected operating mode (Mode) according to the following: Mode: 18a 18b 18c 20 A Engaged Disseng. Disseng. Drive B Engaged Disseng. Engaged Drive C Engaged N/A Engaged Drive D Engaged N/A Engaged. Generate a charging device with a turbine connected to a compressor via a compressor shaft, the compressor having a high speed shaft; a planetary gear coupled between the high speed shaft and an electric motor/generator; a clutch unit; and a power transmission for connecting a crank shaft of the combustion engine to the electric motor/generator, via the clutch unit; wherein the hybrid system further comprises a system control unit configured to operate the hybrid system in different operating modes according to a control algorithm based on one, or a plurality of, input parameters representative of operational properties of the hybrid system, characterized in that the plurality of operating modes comprises: an operating mode A where the electrical motor drives auxiliary loads of the internal combustion engine; an operating mode B where the electric motor starts, or stops, the internal combustion engine; an operating mode C where the electric motor propels the vehicle; and an operating mode D where brake energy from retardation of the vehicle is regenerated to electrical energy; an operating mode A where the electrical motor drives auxiliary loads of the internal combustion engine; an operating mode B where the electric motor starts, or stops, the internal combustion engine; an operating mode C where the electric motor propels the vehicle; and an operating mode D where brake energy from retardation of the vehicle is regenerated to electrical energy; wherein the clutch unit is a first clutch unit and wherein the hybrid system further comprises a second clutch unit; wherein the planetary gear is coupled to the electric motor/generator via the second clutch unit, wherein the hybrid system further comprises: a third clutch unit for connecting the power transmission to the crank shaft of the combustion engine, wherein the system control unit comprises a mode controlling subsystem arranged to control the hybrid system based on the selected operating mode and the input parameters according to a mode control algorithm, wherein the mode control algorithm comprises engaging or disengaging the first, second and third clutch units (18a, 18b, 18c), operating the electric motor in drive mode or generate mode based on the selected operating mode (Mode) according to the following: Mode: 18a 18b 18c 20 A Engaged Disseng. Disseng. Drive B Engaged Disseng. Engaged Drive C Engaged N/A Engaged Drive D Engaged N/A Engaged. Generate a third clutch unit for connecting the power transmission to the crank shaft of the combustion engine, wherein the system control unit comprises a mode controlling subsystem arranged to control the hybrid system based on the selected operating mode and the input parameters according to a mode control algorithm, wherein the mode control algorithm comprises engaging or disengaging the first, second and third clutch units (18a, 18b, 18c), operating the electric motor in drive mode or generate mode based on the selected operating mode (Mode) according to the following: Mode: 18a 18b 18c 20 A Engaged Disseng. Disseng. Drive B Engaged Disseng. Engaged Drive C Engaged N/A Engaged Drive D Engaged N/A Engaged. Generate