Abstract: The invention related to a control method for operating a synchronous machine, the machine comprising an exciter connected to a synchronous generator and a controller (40) for controlling the machine field excitation. The method comprises the steps of predefining a stable operation torque derivative range within which a stable operation of the machine occurs, performing a torque measuring or calculating for the machine, calculating the derivative of said torque, determining whether the calculated torque derivative is within the predefined stable operation torque derivative range for the machine, and, if the torque derivative is not within the predefined stable operation torque derivative range, modifying the machine field excitation to bring the torque derivative within the predefined stable operation torque derivative range.

Abstract: Rotating electric machine comprising a main electric machine, an excitation machine whose rotor is adapted to rotate with a rotor of the main electric machine and produce magnetizing power to the main electric machine, and a controllable rectifier bridge electrically connected to the excitation machine for feeding a field magnetization current to a rotor winding of the main electric machine and comprising controllable semiconductor components for controlling the field magnetization current. The rotating electric machine comprises a controllable circuit connected in parallel with the rotor winding and adapted to lower the magnetization of said rotor winding. The controllable circuit is a self-controlled circuit configured to self-act depending on the voltage across said rotor winding and comprises a discharge resistor dissipating the field magnetization current to lower the magnetization of said rotor winding.

Abstract: The invention related to a control method for operating a synchronous machine, the machine comprising an exciter connected to a synchronous generator and a controller (40) for controlling the machine field excitation. The method comprises the steps of predefining a stable operation torque derivative range within which a stable operation of the machine occurs, performing a torque measuring or calculating for the machine, calculating the derivative of said torque, determining whether the calculated torque derivative is within the predefined stable operation torque derivative range for the machine, and, if the torque derivative is not within the predefined stable operation torque derivative range, modifying the machine field excitation to bring the torque derivative within the predefined stable operation torque derivative range.

Abstract: Rotating electric machine comprising a main electric machine, an excitation machine whose rotor is adapted to rotate with a rotor of the main electric machine and produce magnetizing power to the main electric machine, and a controllable rectifier bridge electrically connected to the excitation machine for feeding a field magnetization current to a rotor winding of the main electric machine and comprising controllable semiconductor components for controlling the field magnetization current. The rotating electric machine comprises a controllable circuit connected in parallel with the rotor winding and adapted to lower the magnetization of said rotor winding. The controllable circuit is a self-controlled circuit configured to self-act depending on the voltage across said rotor winding and comprises a discharge resistor dissipating the field magnetization current to lower the magnetization of said rotor winding.

Abstract: The invention describes a system and a method for controlling an electric generator connected to the power grid during a voltage drop in the power grid, the system comprising a back-to-back converter (2) connected between the generator (3) and the power grid (4) and also, in parallel to the generator side converter (2a), rectifying means (5) connected in series between the generator (3) and the DC-link (2b) of the back-to-back converter (2), thus providing an alternative way for the energy excess at the generator side to enter the DC-link (2b).

Abstract: The invention describes a system and a method for controlling an electric generator connected to the power grid during a voltage drop in the power grid, the system comprising a back-to-back converter (2) connected between the generator (3) and the power grid (4) and also, in parallel to the generator side converter (2a), rectifying means (5) connected in series between the generator (3) and the DC-link (2b) of the back-to-back converter (2), thus providing an alternative way for the energy excess at the generator side to enter the DC-link (2b).

Abstract: An apparatus and method of controlling an electrical generating apparatus is provided. The apparatus includes an electrical generator configured to be connected to an electrical grid and a converter comprising an inverter connected to a rotor of the electrical generator. The apparatus also includes a shunt protection circuit connected to the inverter and the rotor of the electrical generator and a control unit configured to activate and deactivate the inverter and the shunt protection circuit. The control unit is configured to, in response to determining that an abnormal condition is occurring in the electrical generator or an electrical grid to which the electrical generator is connected, deactivate the inverter and activate the shunt protection circuit. Also, after it is determined that the abnormal condition has passed, the control unit is configured to activate the inverter before deactivating the shunt protection circuit.

Abstract: A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

Abstract: A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

Abstract: A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

Abstract: A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

Abstract: The proposed invention describes an alternative for machines with at least one power unit (101) formed by at least one first electronic converter (106) connected to the rotor (109) of the generator, at least one second electronic converter (107) capable of supplying or drawing off the power which the latter is using or producing, and at least one continuous bus (108); with the proposed method it is possible to control the power of the rotor (109), modifying the synchronization speed of the asynchronous generator (103) when it is disconnected from the electrical network supply (102), by means of variation of the frequency of the currents in the rotor (109) which are generated by the first electronic converter (106).

Abstract: A system for controlling and protecting double-fed asynchronous-type generators against symmetrical and asymmetrical faults, such that in the event of a symmetrical or asymmetrical fault, the system remains connected to the grid, absorbs the initial energy transient, and maintains control of the generators.

Abstract: A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

Abstract: The invention relates to wind turbines provided with doubly fed induction generators and with at least one power converter which is novel in that, under certain circumstances, it enables the turbine to operate as a full converter (FC) system, as a doubly fed (DFIG) system or as an asynchronous (AS) system, thereby increasing turbine availability.

Abstract: The present invention describes a pitch control system comprising a principal converter, and auxiliary converter, a direct current motor and a power storage system (accumulator) and has four different operation modes: normal, fault (first level), fault (second level) and emergency. In the case that a fault is detected, the system can move the motor in order to move the vanes to the desired position by making a controlled adjustment.

Abstract: A variable speed wind turbine having a doubly fed induction generator (DFIG) includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine which guarantees a stable voltage to the power converter. Thus, the power converter is not directly connected to the grid allowing the continuous operation of the system during a low voltage event in the grid.

Abstract: A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

Abstract: A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

Abstract: The invention relates to a system for controlling and protecting against symmetrical and asymmetrical faults for double-fed asynchronous-type generators, which, in the event of a symmetrical or asymmetrical fault, remains connected to the grid, absorbing the initial transient, and maintains control of the aerogenerator. In this way, the invention fulfils the requirements of the various different grid connection standards relating to the supply of active and reactive power in fault situations, which are intended to assist in the recovery of the grid.