Method of power split for hybrid powertrain

A method of controlling a hybrid powertrain, the method comprising:

• determining a quantity of regeneration energy in a battery, the battery structured to power an electric motor, the motor connected to an internal combustion engine via a power splitter, wherein the battery, motor, engine, and power splitter comprise a hybrid powertrain structured to power a load;
• determining a marginal displaced fuel consumption value for the hybrid powertrain based on incremental changes in the power contributions of the engine and the motor that is constrained by the quantity of regeneration energy, wherein the marginal displaced fuel consumption value is selected based on a desired marginal displaced fuel consumption contour line defining a region of displaced fuel consumption engine from an engine operating efficiency map in which losses shared with the motor are removed;
• selecting a threshold load condition for the engine that is based on the marginal displaced fuel consumption and the quantity of regeneration energy in the battery;
• interpreting a power demand from a demand input device in communication with the powertrain;
• operating the engine to generate engine power sufficient to meet the power demand not in excess of the threshold load condition;
• operating the motor to generate motor power sufficient to supply the remaining power demand not met by the engine power;
• and
• adjusting the engine power and the motor power in response to changes in power demand and/or regeneration energy.

A method of controlling a hybrid powertrain, the method comprising:

• determining a quantity of regeneration energy in a battery having a capacity, the battery structured to power an electric motor, the motor connected to an internal combustion engine via a power splitter, wherein the battery, motor, engine, and power splitter comprise a hybrid powertrain structured to power a load;
• determining a marginal displaced fuel consumption value for the hybrid powertrain based on incremental changes in the power contributions of the engine and the motor that is constrained by the quantity of regeneration energy, wherein the marginal displaced fuel consumption value is selected based on a desired marginal displaced fuel consumption contour line defining a region of displaced fuel consumption for the engine from an engine operating efficiency map in which losses shared with the motor are removed;
• interpreting a power demand from a demand input device in communication with the powertrain;
• operating the motor to generate motor power based on the marginal displaced fuel consumption value that is sufficient to consume the quantity of regeneration energy at a rate, the rate selected to make available capacity in the battery for storage of additional regeneration energy;
• operating the engine to generate engine power sufficient to supply the remaining power demand not met by the motor power;
• and
• adjusting the engine power and the motor power in response to changes in power demand and/or regeneration energy.

A system for controlling a hybrid powertrain, the system comprising:

• a hybrid powertrain, the powertrain comprising:
• on internal combustion engine structured to generate engine power,
• an electrical motor, the motor structured to generate motor power and to selectively generate electrical power, the motor connected to the engine via a power splitter, and
• a battery, the battery connected to the motor and structured to store regeneration energy;
• and
• a controller in communication with the powertrain and structured to operate upon a torque or power demand to determine a power split between the engine and the motor, wherein the controller is configured to determine a marginal displaced fuel consumption value for the engine based on incremental changes in the power contributions of the engine and the motor that is constrained by a quantity of reclaimed energy in the battery, wherein the marginal displaced fuel consumption value is selected based on a desired marginal displaced fuel consumption contour line defining region of displaced fuel consumption for the engine from an engine operating efficiency map in which losses shared with the motor are removed, wherein the marginal displaced fuel consumption value favors using the quantity of available reclaimed energy at relatively high load conditions, to operate the engine at a speed and torque condition based on the marginal displaced fuel consumption value to meet at least a portion of the torque or power demand, and to operate the motor to generate sufficient motor power to supply a remaining torque or power demand not met by the engine power.