A two mode power-split electric
hybrid system and a method of control said
hybrid system. The
hybrid system is comprised of an engine, a transmission, an
energy storage device and a
control system for effecting said control method. Said transmission is a reconfigurable
power split system, comprising a power-splitting device and an output power path selecting device. The power splitting device includes a compound planetary
gear system and two electric machines which form a local series electric
hybrid system. Said transmission regulates the output power state of said
hybrid system by controlling
power flow within said local series
hybrid system. The hybrid system provides at least two operating mode, an output
power split mode and a compound
power split mode. Said
control system includes multiple controllers and control modules. In accordance with the operating conditions of the hybrid system, said
control system computes and sets system power requirement, allocates ob board power resources and sets engine
operating speed and torque. In addition, said control system sets the
operation mode of the transmission and controls the engine speed by adjusting operating torque of electric machines, based on the differential
signal between reference engine speed and actual engine speed. Said control system is also capable of controlling engine torque through engine controller.