The present disclosure relates to a motor protection relay and a method for starting a motor of the motor protection relay, and particularly, to a motor protection relay capable of softly starting a motor, without a separate starting device, and performing soft starting of the motor more stably, effectively, and simply, by variably controlling start power for starting the motor to the motor through controlling of the relay itself and supplying the variably controlled start power to the motor, and a method for starting a motor thereof.

A method and system for reducing rollback in a counterbalancing system as a holding brake is released is disclosed. A limited amount of movement of a drive shaft is present in the holding brake. A motor drive provides current to the motor with the holding brake set such that a torque is applied at the drive shaft. The current is controlled to generate torque in both directions. The limited amount of movement in the brake may be used to determine a direction and magnitude of torque required to support a mechanical load being applied to the motor. The motor drive then provides a current to generate the necessary torque required to support the load prior to releasing the holding brake.

An apparatus for restarting a medium voltage inverter is disclosed, wherein the medium voltage inverter can be restarted by estimating a rotor speed when an input power returns from an instantaneous defective state to a normal state, whereby a time to restart the medium voltage inverter can be reduced by a simple configuration to dispense with the need to wait until the rotor speed reaches zero speed.

Various embodiments include determining an alternating current (AC) voltage and frequency of a supply voltage coupled to a circuit input. The circuit includes a soft starter circuit that is coupled between the circuit input and a first side of an AC motor. A stator winding configuration of the AC motor is determined. A control transformer is configured in response to the AC voltage and frequency, wherein the control transformer is coupled to the circuit input. A jumper device is configured on a second side of the AC motor in response to the stator winding configuration of the AC motor.

A method for detecting a stall condition of an electric motor. The method can include initiating an open-loop phase. During the open-loop phase, the method can include increasing a rotational speed of an electric motor and obtaining data indicative of a voltage associated with the electric motor while increasing the rotational speed of the electric motor. During the open-loop phase, the method can also include determining a difference between the voltage and a time varying target voltage and detecting a stall condition based at least in part on the difference between the voltage and the time varying target voltage. When a closed-loop condition is satisfied, the method can include initiating a closed-loop phase.

A vibration generation device includes a stator, and a rotor rotatable around a predetermined axis with respect to the stator and having a weight having a gravity center at a position shifted from the predetermined axis. A control section controls a start-up period maximum voltage value, which is a maximum voltage value of a drive signal to be applied to the vibration generation device in a start-up period, to become larger than a steady operation period voltage value, which is a voltage value of the drive signal to be applied to the vibration generation device in a steady operation period. The control section selects at least one of a pluraity of voltage values as the steady operation period voltage value and sets the duration of the start-up period based on the steady operation period voltage value selected.

An embodiment relates to a method for operating a three-phase machine including a rotor and a stator connected to a three-phase network. The stator is connected to the three-phase network via a first semiconductor circuit arrangement for forming a first rotational field rotating in a first direction of rotation in the stator and via a second semiconductor circuit arrangement for forming a second rotational field rotating in a direction of rotation opposite to the first direction of rotation in the stator. The three-phase machine further includes a controller. The method includes controlling, via the controller, semiconductors of the first and second semiconductor circuit arrangement to accelerate the rotor by current pulses of both the first rotational field and second rotational field in the first direction of rotation.

A facility for the production of containers from blanks, which facility includes: a forming unit equipped with a rotating carrousel driven by a motor; a unit for heating blanks, equipped with infrared emitters and a power feed for each emitter; a control unit having in the memory a nominal speed setpoint .sub.N of the rotation of the carrousel and a nominal electrical power setpoint P.sub.N. The control unit is programmed for: controlling the rotation of the carrousel according to the nominal speed setpoint .sub.N. During its acceleration: taking into account the real instantaneous speed of rotation of the carrousel, and regulating the electrical power of the feed to an instantaneous value P such that: $P\left(t\right)=P_N.Math.\frac{}{{}_N}$

Unique systems, methods, techniques and apparatuses of motor starters are disclosed. One exemplary embodiment is a synchronous machine including a plurality of stator phase windings, a rotor, a motor starter, and a controller. The motor starter includes a plurality of wye semiconductor switches and a plurality of delta semiconductor switches. The controller is structured to operate the plurality of wye semiconductor switches and the plurality of delta semiconductor switches so as to couple the plurality of stator phase windings in a delta configuration while an angular speed of the rotor is less than a synchronous speed, and structured to operate the plurality of wye semiconductor switches and the plurality of delta semiconductor switches so as to couple the plurality of stator phase windings in a wye configuration in response to the angular speed of the rotor being equal to the synchronous speed.

A system for controlling an AC motor is provided. The system comprises an electrical connection path for connecting an electrical input of the AC motor to a first phase of alternating current from an electric power supply. The system also comprises two or more motor controllers, each motor controller is located on the electrical connection path between the electric power supply and the AC motor and is operable to regulate current of the first phase passing through it. Each motor controller is connected in parallel, relative to the other motor controllers, to the electrical connection path. At least one processor is configured to control the motor controllers to repeatedly change which of the motor controllers current of the first phase passes through, such that at any given time current of the first phase only passes through one of the motor controllers. A corresponding method is also provided.