Electrical power distribution systems with a bypass unit that electrically engages one of two alternate units for powering a load while electrically isolating the other using a power transfer switch with first and second contactors and mechanical and electrical interlocks to allow a technician to access one of the alternate units when de-energized and in position while the other of the alternate units is energized and powering the load.

A motor control system and a vehicle. The motor control system includes: a vehicle control unit, configured to obtain vehicle state data and output an instruction for cutting off motor output torque when determining an unexpected power transmission failure according to the vehicle state data; and a motor controller unit, connected to the vehicle control unit, and configured to stop outputting motor control torque in response to the instruction for cutting off motor output torque.

A motor control system and a vehicle. The motor control system includes: a vehicle control unit, configured to obtain vehicle state data and output an instruction for cutting off motor output torque when determining an unexpected power transmission failure according to the vehicle state data; and a motor controller unit, connected to the vehicle control unit, and configured to stop outputting motor control torque in response to the instruction for cutting off motor output torque.

An electric working machine in one aspect of the present disclosure includes: a motor; a driver to drive the motor; a first control circuit; and a second control circuit. The first control circuit controls the driver such that the motor rotates in a set rotation direction. The second control circuit is provided separately from the first control circuit. The second control circuit detects a rotation direction of the motor and performs an abnormality handling process to stop rotation of the motor in response to a situation where the detected rotation direction is reverse to the set rotation direction.

An electric motor system implements a redundant wye-wounded motor that includes first phase leads, second phase leads, first neutral leads, and second neutral leads. The first and second phase leads receive alternating current (AC) power from a power supply. A first phase-lead switch selectively connects the first phase leads to the power supply, and a second phase-lead switch selectively connects the second phase leads to the power supply. A first neutral-lead switch selectively connects the first neutral leads to the redundant wye-wounded motor, and a second neutral-lead switch selectively connects the second neutral leads to the redundant wye-wounded motor. A controller detects a circuit fault among a plurality of different types of circuit faults, and controls the operation of one or both of the primary neutral-lead switch and the second neutral-lead switch based on the circuit fault.

A power device fault detection circuit includes a first fault detector configured to measure an output signal of at least one power device and output a first fault signal when a voltage of the output signal of the at least one power device exceeds a first voltage reference level after a first time period; and a second fault detector configured to measure an output signal of the at least one power device and output a second fault signal when a voltage of the output signal of the at least one power device exceeds a second voltage reference level after a second time period, where the first time period implemented by the first fault detector is shorter than the second time period implemented by the second fault detector.

In a method for detecting a motor phase fault of a motor arrangement, the motor phases of which are connected to a drive circuit having a DC voltage intermediate circuit and an inverter. A motor phase voltage at at least one of the motor phases with respect to a reference potential is captured while the inverter is switched off; and a voltage profile of the captured motor phase voltage is used to determine whether there is a motor phase fault on one of the motor phases of the motor arrangement.

A thermal management system is provided. The system includes a temperature sensor, a fan, an electronic circuit breaker (ECB) coupled to the fan to provide electric power to the fan. The system includes a controller coupled to the temperature sensor and the ECB, to direct the ECB to turn off the electric power to the fan responsive to detecting a temperature, from the temperature sensor less than a temperature threshold based on a temperature rating of the fan.

A thermal management system is provided. The system includes a temperature sensor, a fan, an electronic circuit breaker (ECB) coupled to the fan to provide electric power to the fan. The system includes a controller coupled to the temperature sensor and the ECB, to direct the ECB to turn off the electric power to the fan responsive to detecting a temperature, from the temperature sensor less than a temperature threshold based on a temperature rating of the fan.

An apparatus is disclosed that in one embodiment includes a circuit configured to selectively activate a transistor. The circuit is further configured to assert a signal when the circuit detects an electrical short between terminals of the transistor or when the circuit detects the transistor does not conduct current while the transistor is activated by the circuit. The circuit is further configured to output another signal, which is set to a first state or a second state. The other signal is set to the first state when the circuit detects the electrical short. The other signal is set to the second state when the circuit detects the transistor does not conduct current while activated.