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.