One embodiment describes a method that includes determining, using a control circuitry, temperature of a switching device before a make operation by applying a measurement current to an operating coil of the switching device, wherein the measurement current is insufficient to make the switching device; and determining voltage at the operating coil when the measurement current is applied, in which the voltage at the operating coil is directly related to the temperature. The method further includes determining, using the control circuitry, when to apply a pull-in current to the operating coil to close the switching device based at least in part on the voltage at the operating coil, such that the switching device makes at a desired time.

The invention is based on a motor apparatus, in particular on an EC motor apparatus, comprising at least one stator (12a; 12b; 12c) which has at least twelve coils (14a, 14a, 16a, 16a, 18a, 18a, 20a, 20d, 22a, 22b, 24a, 24a; 14b, 14b, 16b, 6b, 18b, 18b, 20b, 20b, 22b, 22b, 24b, 24b; 14c, 16c, 18c, 20c, 22c, 24c, 142c, 44c, 146c, 148c, 150c, 152c), and comprising at least one power supply unit (26a; 26b; 26c). It is proposed that coils (14a, 14a, 16a, 16a, 18a, 18a, 20a, 20a, 22a, 22a, 24a, 24a; 14b, 4b, 16b, 16b, 18b, 18b, 20b, 20b, 22b, 22b, 24b, 24b; 14c, 16c, 18c, 20c, 22c, 24c, 42c, 144c, 146c, 148c, 150c, 152c), which directly follow one another in the circumferential direction (36a; 36b; 36c), of the at least one stator (12a; 12b; 12c) are connected to differing phases of the power supply unit (26a; 26b; 26c) in at least one operating state.

An engine generator, including a general purpose engine, an engine speed of the engine being variably controlled, a generator unit having a three-phase winding and driven by the engine to generate power, an inverter unit converting AC output from the generator unit to AC of a predetermined frequency to output to a load, a connection switching unit switching a connection configuration of the winding to one of a wye-connection and a delta-connection, a load detection unit detecting a size of the load, and a connection switching control unit controlling the connection switching unit to switch the connection configuration to the wye-connection when the size of the load is equal to or lower than a predetermined value, and to switch the connection configuration to the delta-connection when the size of the load is higher than the predetermined value.

A double winding electric machine assembly including a double winding electric machine having a first stator winding and a second stator winding; a first converter including a first modulator and a first power unit whose output is electrically connected to the first stator winding; a second converter including a second modulator and a second power unit whose output is electrically connected to the second stator winding. The assembly includes a current determining system adapted to determine at least one instantaneous phase current in the output of the first power unit; and a synchronizing system adapted to analyse ripple in the at least one instantaneous phase current, and to synchronize the first modulator with the second modulator by adjusting a phase shift between the first modulator and the second modulator until a minimum peak-to-peak current is obtained.

One embodiment describes an interlock for an electromechanical switching system, which includes a housing; a first camming lockout member disposed in the housing and that contacts an auxiliary operator of a first electromechanical switching device; a second camming lockout member disposed in the housing and that contacts an auxiliary operator of a second electromechanical switching device, which the first camming lockout members contacts the second camming lockout member when the first camming lockout member is moved to an actuated position by the first electromechanical switching device to prevent movement of the second camming lockout member to an actuated position.

An electric drive unit for driving devices connectable therewith includes at least one permanent magnets assisted reluctance motor and switching elements operatively associated to the at least one reluctance synchronous motor and designed to switch the connection of the stator windings between a first operating configuration and a second operating configuration, and vice versa, for variable torque and power delivery as a function of the rotation speed of the at least one reluctance synchronous motor.

One embodiment describes a switching device system, which includes a first single pole switching device that selectively connects and disconnects a first phase of electric power to a first winding of a three phase motor; a second single switching device that selectively connects and disconnects a second phase of electric power to a second winding of the three phase motor; in which the first and second single pole switching devices control temperature of the motor by, at a first time, connecting the first phase and the second phase electric power to the motor.

A bridge converter for a multi-phase electrical machine has a number of bridge cells connected in series. Each bridge cell has a controller. The bridge converter includes a sensor operative to provide a commutation signal to at least one controller. A multi-phase electrical machine has a plurality of stator windings and a bridge converter having a number of bridge cells connected in series. Each bridge cell has a controller. The bridge converter includes a sensor operative to provide a commutation signal to at least one controller.

One embodiment describes a method that includes, when a motor is disconnected from a power source: starting, using a control circuitry, a counter at a first voltage zero-crossing by either a source voltage or a back electromotive force generated by the motor; stopping, using the control circuitry, the counter at a next subsequent second voltage zero-crossing by either the source voltage or the back electromotive force; monitoring, using the control circuitry, a trend in counter values; and instructing, using the control circuitry, one or more switching devices to reconnect the power source to the motor after a local minimum in the counter value trend such that the source voltage is leading the back electromotive force.

One embodiment describes a switching device system, which includes a first single pole switching device that selectively connects and disconnects a first phase of electric power to a first winding of a three phase motor; a second single switching device that selectively connects and disconnects a second phase of electric power to a second winding of the three phase motor; in which the first and second single pole switching devices control temperature of the motor by, at a first time, connecting the first phase and the second phase electric power to the motor.