An arrangement contains an asynchronous machine having a rotor and a stator. The arrangement is set up in a generator mode for feeding electrical energy into an AC voltage network. The arrangement is characterized in that the asynchronous machine can be doubly fed. The asynchronous machine can be connected in a matrix configuration to the AC voltage network by a modular multi-level converter, and the modular multi-level converter is set up in a motor mode of the arrangement for starting up the asynchronous machine while short-circuiting the rotor or the stator.

Embodiments of a mixing device power system generally include a power control module, an AC motor, and a variable frequency drive, wherein upon application of AC power to the system, electrical power is provided to the power control module which transmits electrical power to the AC motor, whereby rotation of a mixing spindle is initiated. After the spindle has begun rotating, transmission of electrical power from the power control module to the AC motor is ceased, and substantially simultaneously electrical power transmission is commenced from the power control module to the variable frequency drive which transmits electrical power to the AC motor, whereby rotation of the mixing spindle is continued. A method of using the mixing device power system to mix a fluid sample is also provided.

This method for controlling asynchronous electrical motors of a compressor system, comprises: —receiving an order to start a first asynchronous electrical motor and a second asynchronous electrical motor of a compressor system; —unloading said first and second motors, by operating respectively a first load control unit of the first motor and a second load control unit of the second motor, in order to reduce the mechanical load associated to said motors; —starting the first motor and, only once the first motor is running at nominal speed, starting the second motor, —loading both the first and second electrical motor only once the second motor has started and is running at nominal speed, by operating the first load control unit and the second load control unit, in order to increase the mechanical load associated to said motors.

This method for controlling asynchronous electrical motors of a compressor system, comprises: —receiving an order to start a first asynchronous electrical motor and a second asynchronous electrical motor of a compressor system; —unloading said first and second motors, by operating respectively a first load control unit of the first motor and a second load control unit of the second motor, in order to reduce the mechanical load associated to said motors; —starting the first motor and, only once the first motor is running at nominal speed, starting the second motor, —loading both the first and second electrical motor only once the second motor has started and is running at nominal speed, by operating the first load control unit and the second load control unit, in order to increase the mechanical load associated to said motors.

A motor drive system including a motor including two three-phase winding sets, wherein each three-phase winding set is connected a respective three-phase three-level inverter.

Solar Motor Controller is an electronic device with DC power input terminals that may connect directly to solar PV panels, and output terminals that may connect directly to single or multiphase phase AC electric motors without requiring an energy storage subsystem. The Controller runs electric motors of many frequencies and is capable of interfacing to multiple voltages of solar PV panels with or without maximum power point tracking. The Controller may drive motors in water pumping, HVAC, refrigeration, compressors operation, blowers, machine tools, and many other applications; some controller applications may operate at motor speeds adjusted to conform to power available from attached solar panels.

Solar Motor Controller is an electronic device with DC power input terminals that may connect directly to solar PV panels, and output terminals that may connect directly to single or multiphase phase AC electric motors without requiring an energy storage subsystem. The Controller runs electric motors of many frequencies and is capable of interfacing to multiple voltages of solar PV panels with or without maximum power point tracking. The Controller may drive motors in water pumping, HVAC, refrigeration, compressors operation, blowers, machine tools, and many other applications; some controller applications may operate at motor speeds adjusted to conform to power available from attached solar panels.

An induction machine with localized voltage unbalance compensation is disclosed. The use of an induction machine with a voltage unbalance correction compensator (VUC) may be used to maintain proper working conditions of the machine during intervals of voltage unbalance.

An induction machine with localized voltage unbalance compensation is disclosed. The use of an induction machine with a voltage unbalance correction compensator (VUC) may be used to maintain proper working conditions of the machine during intervals of voltage unbalance.

A combined power motor includes a composite rotor consisting of a plurality of coaxial independent rotors; a composite stator consisting of a plurality of independent stators; a plurality of independent stator windings correspond to the plurality of independent stators respectively; a plurality of power terminals are respectively led out from the plurality of the plurality of independent stator windings; a casing; and a controller. The controller controls on-off of a plurality of winding switches corresponding to the plurality of independent stator windings, thereby achieving functions of soft start, soft stop and variable power operation of the combined power motor, and obtaining a power-saving effect.