An electric working machine may include a brushless motor and a motor controller. The motor controller may include three upper switching elements, three lower switching elements, and a control unit. The control unit may be configured to execute a short-circuit braking operation for applying a braking force to the brushless motor by bringing the three upper switching elements into a non-conductive state and bringing the three lower switching elements into a conductive state. The control unit may be configured to start the short-circuit braking operation at a predetermined timing. When the short-circuit braking operation is started at the predetermined timing, polarities of induced voltages of first to third phase terminals of the brushless motor are reversed by a time when an electrical angle of the brushless motor increases by 180 degrees from the start of the short-circuit braking operation.

A method is provided for operating a rotating field machine of a motor vehicle, wherein at least two winding systems of the rotating field machine are supplied with current from an intermediate circuit via a transmission device having at least two switching units and wherein respective switching sequences for the switching units for supplying the winding system in question are defined. For the switching sequences, first switching states in which current is drawn from the intermediate circuit and second switching states in which no current is drawn are defined. The first switching states of the respective switching sequences are defined so as to be free of overlap. For at least one of the switching sequences, third switching states are defined, in which current is fed into the intermediate circuit. The third switching states are defined so as to overlap with the first switching states of the other switching sequence.

A motor driving system includes a controller, motors and motor drivers. In the normal supplying state of a power supply, the controller controls the motor drivers. The motor drivers output driving signals for driving the motors respectively. In an abnormal state or a power-off state of the power supply, one of the motor drivers is set to be a master driver and the others are set to be slave driver. The master driver activates a deceleration energy backup (DEB) function, powers the slave drivers through a common-DC-bus structure, controls the slave drivers, and during deceleration maintains a ratio between frequencies of the driving signals, until all of the motors are decelerated to stop at the same time.

A motor driving system includes a controller, motors and motor drivers. In the normal supplying state of a power supply, the controller controls the motor drivers. The motor drivers output driving signals for driving the motors respectively. In an abnormal state or a power-off state of the power supply, one of the motor drivers is set to be a master driver and the others are set to be slave driver. The master driver activates a deceleration energy backup (DEB) function, powers the slave drivers through a common-DC-bus structure, controls the slave drivers, and during deceleration maintains a ratio between frequencies of the driving signals, until all of the motors are decelerated to stop at the same time.

Provided are embodiments for a braking system, where the system includes a controller, a motor coupled to an H-bridge network, a DC link coupled to the motor, and an electrical braking system electrically coupled to the motor. The electrical braking system includes a sense circuit configured to sense a condition of the DC link, a brake resistor coupled to the DC link, a drive circuit coupled to the sense circuit, and a transformer for regeneration. Also, provided are embodiments of a method for operating an efficient regenerative resonance electrical braking system.

Driver circuits are provided in correspondence to switching elements of an inverter to output gate signals to the switching elements and built in an IC package in an abnormality detection device (ECU). Motor relays are provided in motor current paths between inter-arm connection points and multi-phase motor windings. Pull-up resistors connect a power supply line and the inter-arm connection points. Pull-down resistors connect the inter-arm connection points and the ground. A checking unit acquires a voltage corresponding to a voltage of each inter-arm connection point as a terminal voltage and checks a short-circuit failure or an open-circuit failure of each motor relay or a disconnection failure of each winding based on the terminal voltage. The pull-up resistors and the pull-down resistors are provided within the IC package in which the driver circuits are built.

An electric working machine may include a brushless motor and a motor controller. The motor controller may include three upper switching elements, three lower switching elements, and a control unit. The control unit may be configured to execute a short-circuit braking operation for applying a braking force to the brushless motor by bringing the three upper switching elements into a non-conductive state and bringing the three lower switching elements into a conductive state. The control unit may be configured to start the short-circuit braking operation at a predetermined timing. When the short-circuit braking operation is started at the predetermined timing, polarities of induced voltages of first to third phase terminals of the brushless motor are reversed by a time when an electrical angle of the brushless motor increases by 180 degrees from the start of the short-circuit braking operation.

An electric working machine may include a brushless motor and a motor controller. The motor controller may include three upper switching elements, three lower switching elements, and a control unit. The control unit may be configured to execute a short-circuit braking operation for applying a braking force to the brushless motor by bringing the three upper switching elements into a non-conductive state and bringing the three lower switching elements into a conductive state. The control unit may be configured to start the short-circuit braking operation at a predetermined timing. When the short-circuit braking operation is started at the predetermined timing, polarities of induced voltages of first to third phase terminals of the brushless motor are reversed by a time when an electrical angle of the brushless motor increases by 180 degrees from the start of the short-circuit braking operation.

A home appliance having a motor includes: an inverter unit; and an inverter control unit for controlling a switching operation of the inverter unit, wherein the inverter control unit generates a braking command for braking the motor, on the basis of an operating mode of the home appliance, and controls the inverter unit to stop the motor when a preset braking time elapses after the braking command is generated, and to execute a first braking mode in which the rotational speed of the motor is reduced in a state where no current flows in the inverter control unit, and then to execute at least one of a second braking mode and a third braking mode in which the rotational speed of the motor is reduced in a state where a current flows in the inverter control unit.

A control device (1) for a goods transport conveyor (100) has a processor (10) that generates control signals for at least one drive motor (350) of a transport section (110; 120; 130) of the goods transport conveyor (100). The motor operates in stop-and-go mode. The processor (10) is configured to control the drive motor (350) by means of a forward phase and/or reverse phase when the transport section (110; 120; 130) of the goods transport conveyor (100) stops such that the torque (M(t)) produced by the drive motor (350) is reduced according to an adjustable stopping function. The processor (10) sets the stopping function depending on detected process data of the transport section (110; 120; 130).