Battery electric hybrid drive for a combine harvester

A hybrid drive system for a combine, comprising:

• an engine driving an output;
• an engine control which produces a current engine load signal and an engine speed signal;
• a battery pack;
• a motor and a generator operatively connected to the output arranged to be used alternately, the motor usable to drive the output and the generator usable to be driven by the output;
• a motor/generator control that is signal-connected to the motor and to the generator to control operation of the motor and generator;
• a hybrid system control;
• and
• wherein the hybrid system control receives a battery pack state-of-charge (SOC) signal from the battery pack, and the hybrid system control also receives the current engine load signal and current engine speed signal from the engine control, and depending upon the SOC signal, the current engine load signal and the current engine speed signal, sends a torque command to the motor/generator control to provide a desired composite speed-torque curve from the engine and the motor;
• wherein the engine control performs the following calculations:
• the engine control determines if it should be using a first or second power-speed curve for engine speed governing, if the battery pack SOC is less than a first pre-determined value, the engine control uses the first power-speed curve;
• if the battery pack SOC is greater than the first pre-determined value, the engine control uses the second power-speed curve;
• the engine control calculates current engine power by multiplying engine output torque and engine speed and a conversion factor;
• the engine control calculates power needed from the motor by applying the engine speed signal to a first look up table of pre-calculated values to output a power signal;
• the engine control calculates maximum power than can be used to discharge and charge the battery pack by applying the battery pack SOC signal and average cell temperature signals to a second look up table of values predetermined by test which outputs the maximum allowable discharging and charging current, these currents are then multiplied by a battery pack output voltage to determine the maximum allowable power to be used for discharging and charging;
• the engine control calculates desired motor or generator power by subtracting the available engine power from the power signal;
• if the desired motor or generator power exceeds the maximum allowable discharge power or is less than the maximum allowable charge power, the motor or generator power is limited to the maximum allowable discharge power or the maximum allowable charge power.

A hybrid drive system for a combine, comprising:

• an engine driving an output;
• an engine control which produces a current engine load signal and an engine speed signal;
• a battery pack;
• a motor and a generator operatively connected to the output arranged to be used alternately, the motor usable to drive the output and the generator usable to be driven by the output;
• a motor/generator control that is signal-connected to the motor and to the generator to control operation of the motor and generator;
• a hybrid system control;
• and
• wherein the hybrid system control receives a battery pack state-of-charge (SOC) signal from the battery pack, and the hybrid system control also receives the current engine load signal and current engine speed signal from the engine control, and depending upon the SOC signal, the current engine load signal and the current engine speed signal, sends a torque command to the motor/generator control to provide a desired composite speed-torque curve from the engine and the motor;
• wherein from 60% to 70% SOC of the battery pack the ability to charge the battery is linearly de-rated to 0% to protect battery life, from 40% to 30% SOC of the battery pack the ability to discharge the battery is linearly de-rated to 0% to protect battery life, between 40% and 60% SOC of the battery pack the battery pack charging and discharging is not de-rated.

A hybrid drive system for a combine, comprising:

• an engine driving an output;
• an engine control which produces a current engine load signal and an engine speed signal;
• a battery pack;
• a motor and a generator operatively connected to the output arranged to be used alternately, the motor usable to drive the output and the generator usable to be driven by the output;
• a motor/generator control that is signal-connected to the motor and to the generator to control operation of the motor and generator;
• a hybrid system control;
• and
• wherein the hybrid system control receives a battery pack state-of-charge (SOC) signal from the battery pack, and the hybrid system control also receives the current engine load signal and current engine speed signal from the engine control, and depending upon the SOC signal, the current engine load signal and the current engine speed signal, sends a torque command to the motor/generator control to provide a desired composite speed-torque curve from the engine and the motor;
• wherein the engine control isochronously governs the engine at a desired isochronous speed;
• the isochronous speed is held until the engine speed reaches rated power;
• once engine load exceeds rated power the engine control allows a linear droop in speed and corresponding increase in power to a peak power point.

A hybrid drive system for a combine, comprising:

• an engine having a rotary output;
• an engine control;
• a battery pack;
• a three phase inverter and an inverter control;
• a motor and a generator arranged to be used alternately connected to the rotary output;
• a hybrid system control, wherein the hybrid system control receives state of charge (SOC) of the battery pack, battery pack voltage, battery pack current, and safe operating current limits to/from the battery pack, and the hybrid system control also receives the current engine load estimate and engine speed from the engine control, and depending upon these variables, a torque command is sent to the inverter control to provide a desired composite speed-torque curve for the engine and the motor wherein the engine control governs the engine at a selected isochronous speed.

A traction drive for a combine harvester, comprising:

• an internal combustion engine having a power of less than 560 kW at rated speed and having peak power over 560 kW at a peak power speed less than rated speed;
• an electric motor;
• at least one battery, wherein the battery is arranged to drive the electric motor;
• a control that causes the at least one battery to power the motor, wherein the electric motor couples with the internal combustion engine to provide the traction drive with over 600 kW power at the peak power speed.

A traction drive for a combine harvester, comprising:

• an internal combustion engine having a power at rated speed of less than 560 kW;
• an electric motor;
• at least one battery, wherein the battery is arranged to drive the electric motor;
• a control that causes the at least one battery to power the motor, wherein the electric motor couples with the internal combustion engine to provide the traction drive with over 560 kW power;
• wherein
• the power level of the engine at rated speed is set to about 480 kW;
• moving down the torque curve to a second speed less than rated speed, the engine power would taper up to about 500 kW and in addition, the electric motor will build power linearly from 0 kW at rated speed to about 40 kW at the second engine speed for a combined power of about 540 kW at the second engine speed;
• and
• if overloading occurs above about 540 kW, the engine will build to a peak power of about 560 kW at a third engine speed less than the second engine speed and the electric motor will build to about 50 kW for a combined power of over 600 kW at the third engine speed.