An arrangement contains an asynchronous machine, which, in generator operation, is configured to feed electric power into an AC network. Accordingly, the asynchronous machine can be dual-fed by a modular multi-stage converter in a matrix configuration. The asynchronous machine has a rotor and the modular multi-stage converter is connected to the rotor of the asynchronous machine.

An off-grid power generating apparatus is provided. The apparatus includes an engine, an alternator and an excitation control device. The alternator includes a rotor, a switch and a stator. The switch is movable between a first position and a second position. An output portion of the stator has first and second segments each of which has at least one coil. The first and second segments are operatively and separately connected with the switch. The first and second segments are connected in series at the first position and in parallel at the second position to provide a high voltage and a low voltage respectively. The excitation control device controls the output voltage to make it have a predetermined frequency, and to regulate the engine speed in response to the load power of the engine.

A system and method of operating a pumped storage power plant using a double fed induction machine with a frequency converter in a rotor circuit is disclosed. A current target value for the rotor current frequency is determined based on a target power to be transmitted between an electrical grid and the double fed induction machine depending on measured actual operating variables. A current inadmissible synchronous deadband is determined depending on variables characterizing a current state of the pumped storage power plant. The synchronous deadband is determined by a permissible minimum required rotor current frequency or speed difference of the rotor speed from the synchronous speed for the stationary operation. The converter is controlled to generate voltages and currents with the current target value of the rotor current frequency if the current target value of the rotor current frequency or speed does not fall in the current inadmissible synchronous deadband.

A power generating apparatus is provided. The alternator includes a rotor, a stator, one or more sensors and an electrical circuit. The rotor includes a plurality of symmetric phase windings while the stator has a single phase winding. The excitation control device is configured to control the induced voltage generated in the stator by regulating the rotating magnetic field generated in the phase windings of the rotor. The excitation control device is also configured to regulate the engine speed responsive to calculated load power. The electrical circuit connects the single phase winding of the stator and the load and is configured in a way that the induced voltage generated in the single phase winding and the output voltage applied to the load are at the same frequency. This arrangement reduces costs of the apparatus.

A power generating apparatus is provided. The alternator includes a rotor, a stator, one or more sensors and an electrical circuit. The rotor includes a plurality of symmetric phase windings while the stator has a single phase winding. The excitation control device is configured to control the induced voltage generated in stator by regulating the rotating magnetic field generated in the phase windings of the rotor. The excitation control device is also configured to regulate the engine speed responsive to calculated load power. The electrical circuit connecting the single phase winding of the stator and the load is configured in a way that the induced voltage generated in the single phase winding and the output voltage applied to the load are at the same frequency. This arrangement reduces costs of the apparatus.

A power generating apparatus and vector control method thereof are provided. The apparatus includes a rotor with plurality of symmetric phase windings, a stator with a single phase winding, sensors and an excitation control device. Current sensors on the stator side and on the rotor side are configured to measure the amplitudes of the load current and the phase current of the rotor respectively. A position sensor is configured to measure the angle of the rotor. The excitation control device is configured to regulate the engine speed responsive to load power. The excitation control device also generates a modulating signal in accordance with the target voltage vector of the rotor and the slip angle and regulates the excitation current in the phase windings of the stator with the modulating signal.

A rotary electric system includes a rotary electric device that includes: a stator including a stator winding; and a rotor. The stator winding includes: a first coil group that generates a rotating magnetic field to rotate the rotor; and a second coil group that generates power with induced electromotive force due to rotation of the rotor.

A power generating apparatus is provided. The alternator includes a rotor, a stator, one or more sensors and an electrical circuit. The rotor includes a plurality of symmetric phase windings while the stator has a single phase winding. The excitation control device is configured to control the induced voltage generated in the stator by regulating the rotating magnetic field generated in the phase windings of the rotor. The excitation control device is also configured to regulate the engine speed responsive to calculated load power. The electrical circuit connects the single phase winding of the stator and the load and is configured in a way that the induced voltage generated in the single phase winding and the output voltage applied to the load are at the same frequency. This arrangement reduces costs of the apparatus.

A power generating apparatus is provided. The alternator includes a rotor, a stator, one or more sensors and an electrical circuit. The rotor includes a plurality of symmetric phase windings while the stator has a single phase winding. The excitation control device is configured to control the induced voltage generated in stator by regulating the rotating magnetic field generated in the phase windings of the rotor. The excitation control device is also configured to regulate the engine speed responsive to calculated load power. The electrical circuit connecting the single phase winding of the stator and the load is configured in a way that the induced voltage generated in the single phase winding and the output voltage applied to the load are at the same frequency. This arrangement reduces costs of the apparatus.

A power generating apparatus and vector control method thereof are provided. The apparatus includes a rotor with plurality of symmetric phase windings, a stator with a single phase winding, sensors and an excitation control device. Current sensors on the stator side and on the rotor side are configured to measure the amplitudes of the load current and the phase current of the rotor respectively. A position sensor is configured to measure the angle of the rotor. The excitation control device is configured to regulate the engine speed responsive to load power. The excitation control device also generates a modulating signal in accordance with the target voltage vector of the rotor and the slip angle and regulates the excitation current in the phase windings of the stator with the modulating signal.