A dual-rotor in-wheel motor based on an axial magnetic field and a control method thereof are provided. The dual-rotor in-wheel motor includes an axle and a hub. The axle is fixedly connected to a frame. The hub relatively rotates around the axle. A disc-shaped intermediate stator is fixedly connected on the axle. A left coil assembly and a right coil assembly are fixedly mounted on two sides of the intermediate stator, respectively. A left rotor and a right rotor are respectively arranged on the two sides of the intermediate stator. The left coil assembly drives the left rotor to rotate, and the right coil assembly drives the right rotor to rotate. A left clutch is arranged between the left rotor and the hub, and a right clutch and a speed reduction mechanism are arranged between the right rotor and the hub.

A braking device for a movable door leaf according to the invention comprises at least one generator, at the output terminals of which, a generator voltage can be generated, by means of which a charging circuit for supplying an open-loop and/or closed-loop control unit may be charged, by means of which an electric braking device, such as, in particular, a braking motor or the like, is controllable, which generates an effective braking force for damping the movement of the door leafs. Therein, the generator shaft of the generator is rotatable for generating the generator voltage with the discharging of a mechanical generator energy storage specifically associated with the generator, which is charged by a respective opening or closing movement of the door, and, during a respective closing or opening movement of the door, is mechanically decoupled from the same or its axis of rotation, and discharges in the state mechanically decoupled from the door leaf or its axis of rotation. Further specified is a door closer, having a rotatable door closer axis, coupleable with a door leaf, cooperating with a mechanical door closer energy storage device, and a correspondingly designed braking device.

A motor drive system includes a battery, double-stator axial gap motors, inverter circuits configured to control power running drive and regenerative drive of the double-stator axial gap motors, step-up/step-down circuits configured to adjust at least voltage of regeneratively generated power of the double-stator axial gap motors, and one or more control devices configured to control drive of the inverter circuits and the step-up/step-down circuits. Each of the double-stator axial gap motors includes two stators. Each of the inverter circuits are connected to a respective one of the two stators. The inverter circuits are connected in series. A single step-up/step-down circuit among the step-up/step-down circuit is provided for each of the axial gap motors. The single step-up/step-down circuit provided for each of the axial gap motors is connected to one of two inverter circuits connected to the two stators among the inverter circuits.

A motor drive system includes a battery, double-stator axial gap motors, inverter circuits configured to control power running drive and regenerative drive of the double-stator axial gap motors, step-up/step-down circuits configured to adjust at least voltage of regeneratively generated power of the double-stator axial gap motors, and one or more control devices configured to control drive of the inverter circuits and the step-up/step-down circuits. Each of the double-stator axial gap motors includes two stators. Each of the inverter circuits are connected to a respective one of the two stators. The inverter circuits are connected in series. A single step-up/step-down circuit among the step-up/step-down circuit is provided for each of the axial gap motors. The single step-up/step-down circuit provided for each of the axial gap motors is connected to one of two inverter circuits connected to the two stators among the inverter circuits.

A power tool includes a three-phase DC motor, a power switching network, a power source, and an electronic processor. A first phase of the motor is connected between a first low side electronic switch and a power source electronic switch, and connected to the power source via a first high side electronic switch in parallel with a diode. The electronic processor is configured to receive an indication to stop the motor during operation of the motor and activate the first low side electronic switch and a second low side electronic switch for a first predetermined time responsive to receiving the indication such that a back-electromagnetic force generated by the motor is stored in the first phase. The electronic processor is configured to deactivate the second low side electronic switch after the first predetermined time such that a first regenerative current is provided to the power source via the diode.

A power tool includes a three-phase DC motor, a power switching network, a power source, and an electronic processor. A first phase of the motor is connected between a first low side electronic switch and a power source electronic switch, and connected to the power source via a first high side electronic switch in parallel with a diode. The electronic processor is configured to receive an indication to stop the motor during operation of the motor and activate the first low side electronic switch and a second low side electronic switch for a first predetermined time responsive to receiving the indication such that a back-electromagnetic force generated by the motor is stored in the first phase. The electronic processor is configured to deactivate the second low side electronic switch after the first predetermined time such that a first regenerative current is provided to the power source via the diode.

A method for controlling at least one servomotor in a braking manner with a frequency converter includes disconnecting a direct-voltage intermediate circuit from an electric alternating-voltage network, braking the servomotor by controlling semiconductor switches of an inverter circuit in a regenerative braking mode in order to reduce the speed of the servomotor, and controlling a brake chopper such that a brake resistor is switched on at a maximum intermediate-circuit voltage, which forms a switch-on threshold for the brake chopper, and is disconnected at a minimum intermediate-circuit voltage, which forms a switch-off threshold for the brake chopper. The switch-on threshold and/or the switch-off threshold are dynamically changed during regenerative braking of the servomotor as a function of the current speed of the servomotor.

A method for controlling at least one servomotor in a braking manner with a frequency converter includes disconnecting a direct-voltage intermediate circuit from an electric alternating-voltage network, braking the servomotor by controlling semiconductor switches of an inverter circuit in a regenerative braking mode in order to reduce the speed of the servomotor, and controlling a brake chopper such that a brake resistor is switched on at a maximum intermediate-circuit voltage, which forms a switch-on threshold for the brake chopper, and is disconnected at a minimum intermediate-circuit voltage, which forms a switch-off threshold for the brake chopper. The switch-on threshold and/or the switch-off threshold are dynamically changed during regenerative braking of the servomotor as a function of the current speed of the servomotor.

A drive arrangement of a conditioning apparatus of a forage harvester having two conditioning rollers, with at least one of the conditioning rollers able to be driven at variable speed via an electrical drive train, includes an electric motor/generator for driving the conditioning roller. The electric motor/generator is able to be operated as a generator for braking the conditioning roller and to return the generated electrical energy into a drive system of the forage harvester.

A drive arrangement of a conditioning apparatus of a forage harvester having two conditioning rollers, with at least one of the conditioning rollers able to be driven at variable speed via an electrical drive train, includes an electric motor/generator for driving the conditioning roller. The electric motor/generator is able to be operated as a generator for braking the conditioning roller and to return the generated electrical energy into a drive system of the forage harvester.