Abstract: Systems and methods are disclosed for reducing engine fuel consumption during regenerative braking. According to certain embodiments, the regenerative braking system has an engine, a generator, a rectifier, a first inverter, a traction motor, and a reverse recovery unit. The generator is configured to be driven by the engine to produce AC electrical power. The rectifier is configured to receive AC electrical power from the generator and convert the AC power to DC power. The first inverter is configured to receive the DC power and convert the DC power to AC power. The traction motor is configured to be driven by the AC power in a traction mode, and to produce regenerated power when rotated in reverse in a regenerative braking mode. The reverse recovery unit has a second inverter and a filter.

Abstract: A motor driver for driving a motor is disclosed. The motor driver has a first power bus, a first switching device coupled between the first power bus and a first terminal of the motor, a second power bus, a second switching device coupled between the second power bus and a second terminal of the motor, and an integrated braking chopper coupled between the first and second power buses. The integrated braking chopper is configured to dissipate an extra power generated by the motor.

Abstract: A control system for an alternating current (AC) machine having a rotor and a stator is disclosed. The control system may include a direct current (DC) link providing a variable DC link voltage; an inverter module operatively coupled between the DC link and the AC machine, and a controller in communication with the inverter module. The inverter module may include a plurality of gates in selective communication with each phase of the stator. The controller may be configured to receive a signal indicative of the variable DC link voltage, receive a signal indicative of a rotational speed of the rotor, receive a torque command, and generate a direct-axis current command and a quadrature-axis current command using the variable DC link voltage, the rotational speed, and the torque command as inputs into a three-dimensional lookup table preprogrammed into a memory associated with the controller.

Abstract: A motor driver for driving a motor is disclosed. The motor driver has a first power bus, a first switching device coupled between the first power bus and a first terminal of the motor, a second power bus, a second switching device coupled between the second power bus and a second terminal of the motor, and an integrated braking chopper coupled between the first and second power buses. The integrated braking chopper is configured to dissipate an extra power generated by the motor.

Abstract: The present disclosure is related to a method for energy management for an electric drive system during regenerative braking of a machine. The machine includes an electric drive assembly. The electric drive assembly includes a generator, a motor, a primary direct current bus and a secondary direct current bus having a regenerative brake assembly. The method of energy management includes connecting at least a chopper and a crowbar across the secondary direct current bus. Further, the method includes directing a secondary power stored during regenerative braking, from the primary or secondary or both the buses through the chopper or the crowbar during fault condition.

Abstract: The present disclosure is related to a method for regenerative braking of a machine. The machine includes an electric drive assembly. The electric drive assembly includes a generator, a motor and a direct current bus and a regenerative brake assembly disposed between them. The regenerative braking assembly includes an inverter. The method includes connecting a phase leg between the direct current bus and the inverter. The phase leg includes an inductor and an electric switch. The phase leg boosts the regenerative voltage. The boosted regenerative voltage is then fed back to control a braking torque from the motor and directed back to the generator.

Abstract: A system for a machine having an electric drive configuration is provided. The system includes a first motor associated with a first wheel, which provides torque to drive the first wheel, a second motor associated with a second wheel, which provides torque to drive the second wheel. The system further includes a controller configured to determine a rotational speed of the first wheel, determine a rotational speed of the second wheel, determine a steering angle of the machine, compare the rotational speeds of the first and second wheels, and adjust the torque to the first wheel if the rotational speed of the first wheel is less than the rotational speed of the second wheel.

Abstract: A traction control system for a machine having an electric drive configuration is disclosed. The traction control system includes an electric motor associated with at least one wheel and adapted to provide braking torque to the wheel. The control system further includes a controller configured to determine a rotational speed of the at least one wheel, compare the rotational speed to an allowable slide threshold, and adjust the braking torque to the at least one wheel during retarding if the speed is less than the allowable slide threshold.

Abstract: The disclosure relates, in one aspect, to a friction brake cooling system for a machine. The cooling system includes at least one pump connected to at least one reservoir containing cooling fluid. A controller is configured to divert a cooling fluid flow through a valve to a first friction brake system and to a second friction brake system based on the use of the systems. In another aspect, the disclosure relates to a method of cooling a first friction brake system and a second friction brake system including diverting a flow of brake cooling fluid to the systems based on the use of the systems.

Abstract: An electric drive system includes a fuel-driven engine (202) driving an electrical power generator (204) that provides power to one or more electric drive motors (210). A method of load management in the electric drive system includes receiving an actual fuel signal, an engine speed (920) signal, a throttle position signal, a motor speed (712) signal, an intake air pressure, a barometric pressure signal, and an intake air temperature signal. These values are used to determine a torque limit. The torque limit is used to limit a torque command to the electric drive motors (210) such that the torque command is consistent with the operating capabilities of the engine (202).

Abstract: The disclosure describes, in one aspect, a method for changing a direction of a machine that is moving in a first direction. The method includes the step of receiving a signal indicative of an intention to change the direction of the machine to a second direction. The method also includes the step of determining whether a signal indicative of a speed of the machine is greater than a threshold based at least in part on an electric motor parameter. Finally, the method includes the step of applying a braking torque to at least one travel mechanism of the machine in response to a signal indicative of an accelerator pedal position until the speed reaches the threshold.

Abstract: The disclosure relates, in one aspect, to a friction brake cooling system for a machine. The cooling system includes at least one pump connected to at least one reservoir containing cooling fluid. A controller is configured to divert a cooling fluid flow through a valve to a first friction brake system and to a second friction brake system based on the use of the systems. In another aspect, the disclosure relates to a method of cooling a first friction brake system and a second friction brake system including diverting a flow of brake cooling fluid to the systems based on the use of the systems.

Abstract: The disclosure relates, in one aspect, to a friction brake cooling system for a machine. The cooling system includes at least one pump connected to at least one reservoir containing cooling fluid. A controller is configured to divert a cooling fluid flow through a valve to a first friction brake system and to a second friction brake system based on the use of the systems. In another aspect, the disclosure relates to a method of cooling a first friction brake system and a second friction brake system including diverting a flow of brake cooling fluid to the systems based on the use of the systems.

Abstract: A traction control system for a machine having an electric drive configuration is disclosed. The fraction control system includes an electric motor associated with at least one wheel and adapted to provide braking torque to the wheel. The control system further includes a controller configured to determine a rotational speed of the at least one wheel, compare the rotational speed to an allowable slide threshold, and adjust the braking torque to the at least one wheel during retarding if the speed is less than the allowable slide threshold.

Abstract: An electric drive system includes a fuel-driven engine (202) driving an electrical power generator (204) that provides power to one or more electric drive motors (210). A method of load management in the electric drive system includes receiving an actual fuel signal, an engine speed (920) signal, a throttle position signal, a motor speed (712) signal, an intake air pressure, a barometric pressure signal, and an intake air temperature signal. These values are used to determine a torque limit. The torque limit is used to limit a torque command to the electric drive motors (210) such that the torque command is consistent with the operating capabilities of the engine (202).

Abstract: The disclosure describes, in one aspect, a system for a machine having an electric drive configuration. The system includes a first motor associated with a first wheel, the first motor adapted to provide torque to drive the first wheel, a second motor associated with a second wheel, the second motor adapted to provide torque to drive the second wheel. The system further includes a controller adapted to determine a rotational speed of the first wheel, determine a rotational speed of the second wheel, determine a steering angle of the machine, compare the rotational speeds of the first and second wheels, and adjust the torque to the first wheel if the rotational speed of the first wheel is less than the rotational speed of the second wheel.

Abstract: An electric drive system includes a fuel-driven engine (202) driving an electrical power generator (204) that provides power to one or more electric drive motors (210). A method of load management in the electric drive system includes receiving an actual fuel signal, an engine speed (920) signal, a throttle position signal, a motor speed (712) signal, an intake air pressure, a barometric pressure signal, and an intake air temperature signal. These values are used to determine a torque limit. The torque limit is used to limit a torque command to the electric drive motors (210) such that the torque command is consistent with the operating capabilities of the engine (202).

Abstract: A traction control system (30) for a machine (10) includes a driven wheel (22) operated by a motor that is controlled by an electronic controller (54). A speed sensor (44) measures the speed of the driven wheel (22), and communicates a wheel (22) speed to the electronic controller (54). A travel speed sensor (44) measures the travel speed of the machine (10) and communicates it to the electronic controller (54). A steering sensor (44) measures a displacement of the machine (10)'s steering system (28), and communicates a steering angle to the electronic controller (54). The electronic controller (54) calculates a speed ratio, based on the wheel (22) speed and the travel speed, and an expected slip ratio, based on the steering angle. The speed ratio is corrected by application of the expected slip ratio to yield a corrected speed ratio that is indicative of a slip condition. The operation of the motor is then adjusted to address the slip condition.

Abstract: The disclosure describes, in one aspect, a method for changing a direction of a machine that is moving in a first direction. The method includes the step of receiving a signal indicative of an intention to change the direction of the machine to a second direction. The method also includes the step of determining whether a signal indicative of a speed of the machine is greater than a threshold based at least in part on an electric motor parameter. Finally, the method includes the step of applying a braking torque to at least one travel mechanism of the machine in response to a signal indicative of an accelerator pedal position until the speed reaches the threshold.

Abstract: An electric drive system includes a fuel-driven engine (202) driving an electrical power generator (204) that provides power to one or more electric drive motors (210). A method of load management in the electric drive system includes receiving an actual fuel signal, an engine speed (920) signal, a throttle position signal, a motor speed (712) signal, an intake air pressure, a barometric pressure signal, and an intake air temperature signal. These values are used to determine a torque limit. The torque limit is used to limit a torque command to the electric drive motors (210) such that the torque command is consistent with the operating capabilities of the engine (202).