A DC electric motor including both coils in a delta configuration and coils in a wye configuration. When pulses are fed to selected ones of the coils to power the electric motor, both coils from the delta configuration and coils from the wye configuration are fed with the DC pulse. In some embodiments, a similar electric generator is provided.

A motor drive apparatus includes a connection switching device that switches a connection state of windings of a first motor by switches; an inverter that applies an alternating-current voltage to the windings; a first control device that controls the inverter and the connection switching device; and a second control device that controls a second motor for an element that affects the first motor. Control by the first control device when switching includes a first stage of bringing an effective value of alternating current flowing through the windings close to zero compared to that before the connection state is switched; and a second stage of suspending output of the alternating-current voltage from the inverter. The second control device keeps the second motor running during the first and second stages, and the first control device switches the switches in the second stage.

Methods and systems are provided for a winding reconfiguration assembly for an electric machine. The winding reconfiguration assembly includes a multi-position contactor device designed to switch stator windings in the electric machine between a first electric configuration in a first position and a second electric configuration in a second position. The winding reconfiguration assembly further includes an electromagnetic actuator configured switch the multi-position contactor device between the first position and the second position in response to a change in the polarity of a coil in the electromagnetic actuator.

The present disclosure relates to a motor driving apparatus and an air conditioner including the same. The motor driving apparatus and the air conditioner including the same according to an embodiment of the present disclosure include: a switching device disposed between an inverter and a motor; and a controller, which in response to windings of the motor being switched from a first connection to a second connection, controls an operating frequency of the motor to be less than or equal to a first frequency, and in response to the windings of the motor being switched from the second connection to the first connection, controls an operating frequency of the motor to be less than or equal to a second frequency which is less than the first frequency. Accordingly, burnout of the switching device for switching connection of the motor windings may be prevented.

An apparatus for enabling a two-stage inverter to switch between modes includes: a first inverter unit, a second inverter unit, a load connected between the first inverter unit and the second inverter unit, a mode switching unit connected between the load and the second inverter unit, and a control unit configured to drive the load in an one-stage inverter mode or a two-stage inverter mode by performing a control that turns on or off the mode switching unit.

Systems and methods for providing an adaptive nut removal mode in a power tool. The power tool includes a housing and a motor. The motor includes a rotor and a stator. The stator includes a plurality of stator windings. A power switching circuit is configured to provide a supply of power from a power source to the motor. An electronic controller is configured to control the power tool to remove a fastener from a joint. The electronic controller is configured to monitor a torque of the motor, determine whether the torque of the motor is equal to or less than a threshold torque value, operate, when the torque is greater than the threshold torque value, the motor in an loosening mode while the torque of the motor decreases, and increase, when the torque is equal to or less than the threshold torque value, a speed of the motor.

A system includes: an inverter configured to convert DC power from a voltage source to AC power to drive a motor including a plurality of windings, wherein the inverter includes: a first inverter to be connected to a first end of a first winding of the plurality of windings and a first end of a third winding of the plurality of windings; a second inverter to be connected to a first end of a second winding of the plurality of windings and a second end of the first winding of the plurality of windings; and a third inverter to be connected to a second end of the third winding of the plurality of windings and a second end of the second winding of the plurality of windings.

A system includes an inverter including: a first three-phase inverter including three legs, wherein each leg of the three legs is to be connected to a first node of a voltage source, to be connected to a second node of the voltage source, and to be connected to a first end of a respective phase winding among the three phase windings of the motor; a breaker switch including a first connection and a second connection, the first connection connected to the second node of the voltage source; and a second three-phase inverter including three legs, wherein each leg of the three legs is to be connected to the first node of the voltage source, connected to the second connection of the breaker switch, and to be connected to a second end of the respective phase winding among the three phase windings of the motor.

Disclosed solutions relate to electrical inverters. In an example, a system including an inverter to convert DC power from a voltage source to AC power to drive a winding of a motor is disclosed. The inverter includes a first power module, which includes a first inverter to be connected to a first end of the winding and to be connected to the voltage source. The first inverter is configured to output first AC power to the first end of the winding. The first power module includes a second inverter to be connected to a second end of the winding and to be connected to the voltage source. The second inverter is configured to output second AC power to the second end of the winding. first power module includes a changeover switch to selectively connect and disconnect the second end of the winding to and from a neutral connection.

Disclosed solutions relate to electrical inverters. In an example, an inverter to convert DC power from a voltage source to AC power to drive a motor is disclosed. The inverter includes a first power module. The first power module includes first phase switches, second phase switches and positive DC power tabs connected to a positive DC rail to provide positive DC power to the first phase switches and the second phase switches. The inverter further includes negative DC power tabs connected to a negative DC rail to provide negative DC power to the first phase switches and the second phase switches. The inverter further includes first phase AC power tabs to receive AC power from the first phase switches. The inverter further includes second phase AC power tabs to receive AC power from the second phase switches.