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 semiconductor device for controlling a three-phase motor with double windings, includes a first inverter that drives a first winding of the three-phase motor, a second inverter that drives a second winding of the three-phase motor and a communication line between the first and second inverters. The first and second inverters, through the communication line, notify a respective operation state each other.

Pairs of phases of an AC power source are connected to pairs of phases of a motor in a first sequence that repeats at a first frequency. The motor is braked by connecting pairs of phases of the AC power source to pairs of phases of the motor in a second sequence that is reversed with respect to the first sequence and that repeats at a second frequency less than the first frequency. In further aspects, pairs of phases of an AC power source are connected to pairs of phases of a motor in a first sequence. All of the phases of the motor are subsequently disconnected from the AC power source for a predetermined dwell interval having a duration greater than a time constant of the motor, and thereafter the motor is braked by connecting pairs of phases of the AC power source to pairs of phases of the motor in a second sequence that is reversed with respect to the first sequence. Motor starters implementing such operations are also disclosed.

Pairs of phases of an AC power source are connected to pairs of phases of a motor in a first sequence that repeats at a first frequency. The motor is braked by connecting pairs of phases of the AC power source to pairs of phases of the motor in a second sequence that is reversed with respect to the first sequence and that repeats at a second frequency less than the first frequency. In further aspects, pairs of phases of an AC power source are connected to pairs of phases of a motor in a first sequence. All of the phases of the motor are subsequently disconnected from the AC power source for a predetermined dwell interval having a duration greater than a time constant of the motor, and thereafter the motor is braked by connecting pairs of phases of the AC power source to pairs of phases of the motor in a second sequence that is reversed with respect to the first sequence. Motor starters implementing such operations are also disclosed.

To provide a motor controller which can suppress occurrence of a torque difference between systems, even if a DC voltage difference occurs between systems, in the case where each system is provided with a DC power source. A motor controller is provided with a first controller that controls so that the first q-axis current detection value approaches the second q-axis current detection value or the second q-axis current command value obtained from the second controller, when determining that the first DC voltage is higher than the second DC voltage; and a second controller that controls so that the second q-axis current detection value approaches the first q-axis current detection value or the first q-axis current command value obtained from the first controller, when determining that the second DC voltage is higher than the first DC voltage.

A brake control system of a motor is provided. When a control circuit intends to brake the motor, the control circuit controls a driver circuit to turn off a first high-side switch and a second high-side switch, and to fully turn on the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off one of the first low-side switch and the second low-side switch, and to continually turn on the other one of the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off the other one of the first low-side switch and the second low-side switch, and to turn on the one of the first low-side switch and the second low-side switch, for a period of time.

A brake control system of a motor is provided. When a control circuit intends to brake the motor, the control circuit controls a driver circuit to turn off a first high-side switch and a second high-side switch, and to fully turn on the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off one of the first low-side switch and the second low-side switch, and to continually turn on the other one of the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off the other one of the first low-side switch and the second low-side switch, and to turn on the one of the first low-side switch and the second low-side switch, for a period of time.

An electric machine includes a rotor and a stator. The stator includes a stator core having a plurality of slots. The stator further includes a plurality of drive modules configured to collectively produce an aggregate rotating magnetic field. Each respective drive module includes a power supply configured to generate a respective poly-phase alternating current (AC) output and is connected to a plurality of respective conductor windings. Each respective conductor winding includes a plurality of respective conductors, each respective conductor configured to carry a respective phase of the respective poly-phase AC output. Each respective drive module is configured to generate a rotating, poly-phase, multipole magnetic field. The rotating, poly-phase, multipole magnetic field is a superimposition of a plurality of respective mono-phase, multiple magnetic fields being generated by a respective conductor of the respective conductor winding.

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.

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.