A direct current traction motor control system includes plural motors of with each of the motors configured to be coupled with a different axle of a vehicle and to rotate the axle to propel the vehicle. The motors are coupled with a DC bus and configured to receive DC via the DC bus to power the motors. The system also includes plural switch assemblies with each of the switch assemblies having an H-bridge circuit coupled with a different motor of the motors to control rotation of the motor. The system includes a controller configured to communicate control signals to the switch assemblies to individually control the H-bridge circuits to control one or more of torques output by the motors or rotation directions of the motors.

A direct current traction motor control system includes plural motors of with each of the motors configured to be coupled with a different axle of a vehicle and to rotate the axle to propel the vehicle. The motors are coupled with a DC bus and configured to receive DC via the DC bus to power the motors. The system also includes plural switch assemblies with each of the switch assemblies having an H-bridge circuit coupled with a different motor of the motors to control rotation of the motor. The system includes a controller configured to communicate control signals to the switch assemblies to individually control the H-bridge circuits to control one or more of torques output by the motors or rotation directions of the motors.

This invention concerns an electric drive system (200) for driving an output. The electric drive system comprises: a first electric motor (250) arranged to drive a first input shaft (230) at a first angular velocity, ω.sub.1, and a second electric motor (260) arranged to drive a second input shaft (240) at a second angular velocity, ω.sub.2. A gear mechanism (210) is provided and is arranged to transmit angular rotation of the first (230) and second (240) input shafts to drive the output (220) at an output angular velocity, ω.sub.out, such that ω.sub.out is proportional to aω.sub.1-bω.sub.2, where a and b are constants. The electric drive system (200) further comprises a controller (270) arranged to control operation of the first (250) and second (260) electric motors. When the output (220) is to be driven from ω.sub.out=0, the controller (270) is arranged to control the first (250) and second (260) electric motors to drive the first (230) and second (240) input shafts. The input shafts are driven in a first phase to primary first and second angular velocities, ω.sub.1,p and ω.sub.2,p, such that aω.sub.1,p≈bω.sub.2,p. The input shafts are also subsequently driven in a second phase in which the first angular velocity, ω.sub.1, or the second angular velocity, ω.sub.2, or both are varied such that aω 1≠b.sub.ω2 and the output is driven from ω.sub.out=0. The result of this is that the motors run in a more efficient part of their output profile, even whilst the vehicle is at rest, pulling off (especially in situations of high output load such as on off-road or otherwise difficult terrain), or moving at low velocity.

This invention concerns an electric drive system (200) for driving an output. The electric drive system comprises: a first electric motor (250) arranged to drive a first input shaft (230) at a first angular velocity, ω.sub.1, and a second electric motor (260) arranged to drive a second input shaft (240) at a second angular velocity, ω.sub.2. A gear mechanism (210) is provided and is arranged to transmit angular rotation of the first (230) and second (240) input shafts to drive the output (220) at an output angular velocity, ω.sub.out, such that ω.sub.out is proportional to aω.sub.1-bω.sub.2, where a and b are constants. The electric drive system (200) further comprises a controller (270) arranged to control operation of the first (250) and second (260) electric motors. When the output (220) is to be driven from ω.sub.out=0, the controller (270) is arranged to control the first (250) and second (260) electric motors to drive the first (230) and second (240) input shafts. The input shafts are driven in a first phase to primary first and second angular velocities, ω.sub.1,p and ω.sub.2,p, such that aω.sub.1,p≈bω.sub.2,p. The input shafts are also subsequently driven in a second phase in which the first angular velocity, ω.sub.1, or the second angular velocity, ω.sub.2, or both are varied such that aω 1≠b.sub.ω2 and the output is driven from ω.sub.out=0. The result of this is that the motors run in a more efficient part of their output profile, even whilst the vehicle is at rest, pulling off (especially in situations of high output load such as on off-road or otherwise difficult terrain), or moving at low velocity.

A direct current traction motor control system includes plural motors of with each of the motors configured to be coupled with a different axle of a vehicle and to rotate the axle to propel the vehicle. The motors are coupled with a DC bus and configured to receive DC via the DC bus to power the motors. The system also includes plural switch assemblies with each of the switch assemblies having an H-bridge circuit coupled with a different motor of the motors to control rotation of the motor. The system includes a controller configured to communicate control signals to the switch assemblies to individually control the H-bridge circuits to control one or more of torques output by the motors or rotation directions of the motors.

A direct current traction motor control system includes plural motors of with each of the motors configured to be coupled with a different axle of a vehicle and to rotate the axle to propel the vehicle. The motors are coupled with a DC bus and configured to receive DC via the DC bus to power the motors. The system also includes plural switch assemblies with each of the switch assemblies having an H-bridge circuit coupled with a different motor of the motors to control rotation of the motor. The system includes a controller configured to communicate control signals to the switch assemblies to individually control the H-bridge circuits to control one or more of torques output by the motors or rotation directions of the motors.

A safety procedure is provided for a vehicle having high-current components and high-voltage components, in particular in a hybrid or electric vehicle. In the event of a crash, in addition to a physical separation of a battery from a HV intermediate circuit, the HV intermediate circuit is discharged.

A drive system for driving a and/or being driven by a coupled machine comprises an output for driving the and/or by the coupled machine, a first machine unit with at least one electric machine and a second machine unit with at least one electric machine. The first machine unit has a transmission gear and the drive system has a first switching unit which is set up in such a way that, in a first operating state of the first switching unit, it operatively connects the transmission gear of the first machine unit and the output in a torque-transmitting manner and, in a second operating state of the first switching unit, this operative connection is interrupted. In addition or alternatively, the drive system has a first switching device which is set up in such a way that, in a first operating state of the first switching device, the electrical machine of the first or second machine unit and a power supply and/or energy storage device are electrically connected by it, and, in a second operating state of the first switching device, said connection is disconnected and an active short circuit of said electrical machine is effected.

A vehicular propulsion system is described that uses a plurality of direct current (DC) motors operatively attached to a common drive shaft or shafts of an electric vehicle (EV) or boat. Each motor is powered separately by direct current from a battery cassette or trays swappably inserted into the chassis of the vehicle. The battery cassettes are secured in racks, with one or more individual battery cassettes connected to each of individual motors. The individual battery cassettes are sized to have a weight suitable so as to be readily swapped out as needed for recharging, maintenance or replacement, enabling vehicle range to be extended en route by exchanging depleted battery cassettes for new batteries whenever needed. DC motors may be selected to obtain efficiencies greater than obtainable with AC motors, but require no expensive inverter unit.

Embodiments disclosed herein include a first motor having a high gear ratio, a second motor having a low gear ratio, and a drive shaft, the first and second motors being connected to a load via the drift shaft. The motor system is arranged to at least one of electrically and mechanically disconnect the first motor when a speed of the first motor reaches a threshold speed such that the first motor does not act as a generator and consume mechanical power. In some embodiments, the first motor is a torque booster and the second motor is a high speed motor. The first motor may be electrically disconnected via one or more relays, couplers, and additional switching semiconductors. The first motor may be mechanically disconnected via a clutch.