One embodiment describes a three-phase electromechanical switching device, which includes three single-phase switching devices mechanically and electrically coupled in parallel with one another, each single-phase switching device including a direct current electromagnetic operator that in operation receives a direct current control signal for switching of the device, stationary contacts disposed in a respective device housing, and a movable assembly that in operation is displaced by energizing the operator and that include movable contacts that open and close, with the stationary contacts, a single current carrying path through the respective single-phase switching device; in which each of the single-phase switching devices receives control signals from control circuitry coupled to the operators of the respective single-phase switching devices to cause at least one of the single-phase switching devices to open or close the single current carrying path at a desired time coordinated with a current zero-crossing or a predicted current zero-crossing of a phase of three-phase power.

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.

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.

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.

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.

The present invention relates to an electromagnetic contactor, and more particularly, to an electromagnetic contactor for star-delta driving, which is capable of rapidly and safely switching a connection of a 3-phase motor from a star connection to a delta connection and simplifying configurations of a connection circuit and an opening/closing device. According to the electromagnetic contactor for star-delta driving and a control device thereof of the present invention, the connection of the 3-phase motor can be switched rapidly and safely from the star connection to the delta connection, and the configuration of the connection circuit and a control circuit of a power supply thereof and a magnetic switch configuration can be simplified, and thus, there is an effect of saving space by reducing the size and weight of a product and reducing the numbers of power wirings and control circuit wirings. In addition, a magnetic switch between star and delta connections is interlocked by using a timer and an auxiliary contact, so as to improve the convenience of an operator and reduce construction time. In addition, because a timer base and the control device are ready-made in the form of manufactured goods, it is easy to use the products and there is very little risk of causing a misconnection in the control device. Thus, there are effects of improving the safety of a construction operator at a construction site and a general user, and improving driving components and circuit protection.

The present invention relates to an electromagnetic contactor, and more particularly, to an electromagnetic contactor for star-delta driving, which is capable of rapidly and safely switching a connection of a 3-phase motor from a star connection to a delta connection and simplifying configurations of a connection circuit and an opening/closing device. According to the electromagnetic contactor for star-delta driving and a control device thereof of the present invention, the connection of the 3-phase motor can be switched rapidly and safely from the star connection to the delta connection, and the configuration of the connection circuit and a control circuit of a power supply thereof and a magnetic switch configuration can be simplified, and thus, there is an effect of saving space by reducing the size and weight of a product and reducing the numbers of power wirings and control circuit wirings. In addition, a magnetic switch between star and delta connections is interlocked by using a timer and an auxiliary contact, so as to improve the convenience of an operator and reduce construction time. In addition, because a timer base and the control device are ready-made in the form of manufactured goods, it is easy to use the products and there is very little risk of causing a misconnection in the control device. Thus, there are effects of improving the safety of a construction operator at a construction site and a general user, and improving driving components and circuit protection.

The technologies described and recited herein pertain to a permanent magnet motor having multiple voltage taps so that the motor may run in multiple configurations, e.g., a low-range and a high-range, and have multiple optimal operating points.

The present disclosure relates to an apparatus and method for controlling switching of a wiring mode of a motor capable of being operated in a plurality of wiring modes, a motor control apparatus includes a motor including a rotor that rotates according to a motor torque by a pulse width modulation (PWM) control, a switching unit provided at the motor and switching a wiring method inside the motor so that the motor is driven according to another wiring mode, and a controller generating a speed command frequency for controlling a rotation speed of the rotor, and controlling the switching unit so that the wiring mode of the motor is switched according to a result of comparing the speed command frequency with a switching boundary frequency according to the wiring mode of the motor, wherein when the PWM control is stopped in response to the switching of the wiring mode, the controller estimates a rotation state of the rotor that rotates inertially, and when the PWM control is restarted, the controller sets the estimated rotation state of the rotor as an initial value of the rotor, and controls a rotation speed of the motor of which the wiring mode is switched based on the set initial value of the rotor.

Methods and control apparatus for operating a three-phase electric motor are described, in which the motor windings are switched between Star and Delta connections depending on torque requirements, and in which the motor windings are switched to a braking mode when braking torque is required. The electromagnetic torque of the motor is monitored, and a command to switch from Star to Delta is given when the electromagnetic torque rises to reach or exceed a threshold.