Abstract: A method of controlling brake power flow for a vehicle with an electrically variable transmission is provided. When the brake power exceeds a power absorption capability of the energy storage system, then vehicle conditions are evaluated to determine if control of an engine fan is allowable. When conditions allow for fan control then the remaining brake power is provided for operation of the engine fan. Any excess brake power is dissipated through the exhaust brake or used by other vehicle accessories.

Abstract: A method for controlling operation of a hybrid powertrain is proposed, the hybrid powertrain comprising an internal combustion engine, an electric energy storage device, an electric machine, and an electro-mechanical transmission. The engine and the electric machine and the transmission are operative to transmit torque therebetween to generate an output. The method comprises determining optimum engine operation and an engine capability, and an operator torque request. A limit to the engine capability is determined based upon optimum engine operation, engine capability, and states of the parameters of the electrical energy storage device. Power limits are determined. The limit to the engine capability is adjusted based upon the power limits of the energy storage device. The engine operation is controlled based upon the engine capability and the adjusted limit to the engine capability.

Abstract: There is described hybrid powertrain operation and control. Preferred power flows from an engine to an electro-mechanical transmission and from an energy storage system to an electric machine are determined based upon an operator torque request. Operation of the engine, the electric machine, and the electro-mechanical transmission are controlled to substantially meet the operator torque request. Actual power flow from the energy storage device is monitored. The power flow from the engine is adjusted based upon a difference between the actual and preferred power flows from the energy storage device.

Abstract: A method of controlling brake power flow for a vehicle with an electrically variable transmission is provided. When the brake power exceeds a power absorption capability of the energy storage system, then vehicle conditions are evaluated to determine if control of an engine fan is allowable. When conditions allow for fan control then the remaining brake power is provided for operation of the engine fan. Any excess brake power is dissipated through the exhaust brake or used by other vehicle accessories.

Abstract: There is described hybrid powertrain operation and control. Preferred power flows from an engine to an electromechanical transmission and from an energy storage system to an electric machine are determined based upon an operator torque request. Operation of the engine, the electric machine, and the electromechanical transmission are controlled to substantially meet the operator torque request. Actual power flow from the energy storage device is monitored. The power flow from the engine is adjusted based upon a difference between the actual and preferred power flows from the energy storage device.

Abstract: A method for controlling operation of a hybrid powertrain is proposed, the hybrid powertrain comprising an internal combustion engine, an electric energy storage device, an electric machine, and an electro-mechanical transmission. The engine and the electric machine and the transmission are operative to transmit torque therebetween to generate an output. The method comprises determining optimum engine operation and an engine capability, and an operator torque request. A limit to the engine capability is determined based upon optimum engine operation, engine capability, and states of the parameters of the electrical energy storage device. Power limits are determined. The limit to the engine capability is adjusted based upon the power limits of the energy storage device. The engine operation is controlled based upon the engine capability and the adjusted limit to the engine capability.

Abstract: The present invention provides a method for estimating the power capability of the primary power source of a hybrid vehicle. The method preferably includes calculating a first indicator based on a broadcast estimate from the primary power source of a hybrid vehicle. A second indicator is obtained by calculating the difference between the value of a torque command and the amount of torque reportedly delivered in response to the torque command. A third indicator is calculated based on a plurality of system dynamic equations. The first, second and third indicators are then combined to obtain an estimate of the power capability of the primary power source.

Abstract: The present invention provides a method adapted to control a hybrid electric vehicle having a primary power source and a secondary power source. The method includes estimating the power capability of the primary power source, and thereafter obtaining a power command from the vehicle's driver. A primary power demand and a secondary power demand which collectively meet the driver power command are then established, and a desired power balance between the primary power demand and the secondary power demand is also obtained. A system power capability is calculated based on the desired power balance and the estimated power capability. The method of the present invention then determines if the driver power command exceeds the system power capability. If the driver power command exceeds the system power capability, the driver power command limited and thereafter the limited driver power command is executed.