Abstract: An apparatus and method of controlling a frequency converter is provided. First, subsynchronous components in the electrical grid are identified using voltage measurements of the electrical grid. The subsynchronous components of the electrical grid are then used to determine set points for damping currents. These damping currents are then added to current set points calculated by power regulation loops to generate total current set points. Thereafter, the frequency converter is controlled based on the total current set points.

Abstract: Optimizes the operation and control of electric generators against events produced in the power grid, such as voltage dips or overvoltages, comprising the following steps: detecting that the DC bus voltage level (Vbus) (301) exceeds the maximum operating limit established in normal conditions; enabling activation permission of the chopper (201); activating the different operating states (304) of the chopper (201) according to the DC bus voltage level (Vbus) (301) and to the current entering the DC bus (Iin.bus) from the generator; detecting that the DC bus voltage level (Vbus) (301) is within the normal operating range; enabling deactivation permission of the chopper (201); deactivating the different operating states (304) of the chopper (201) according to the DC bus voltage level (Vbus) (301) and to the current entering the DC bus (Iin.bus) from the generator.

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 present invention relates to a method and system for controlling a wind power installation connected to an electrical power grid, in case of a fault in said grid. In the electrical machines that form part of the wind power installation, generators and transformers, it is possible to change the impedance of the neutral closure introducing a plurality of active and passive elements. This limits the currents during the grid fault, thereby reducing the peak torque in the mechanical train of the wind turbines and allows guaranteeing compliance with the network connection requirements, as control of the active and reactive currents is maintained at all times.

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: 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: Optimizes the operation and control of electric generators against events produced in the power grid, such as voltage dips or overvoltages, comprising the following steps: detecting that the DC bus voltage level (Vbus) (301) exceeds the maximum operating limit established in normal conditions; enabling activation permission of the chopper (201); activating the different operating states (304) of the chopper (201) according to the DC bus voltage level (Vbus) (301) and to the current entering the DC bus (Iin.bus) from the generator; detecting that the DC bus voltage level (Vbus) (301) is within the normal operating range; enabling deactivation permission of the chopper (201); deactivating the different operating states (304) of the chopper (201) according to the DC bus voltage level (Vbus) (301) and to the current entering the DC bus (Iin.bus) from the generator.

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: The present invention relates to a method and system for controlling a wind power installation connected to an electrical power grid, in case of a fault in said grid. In the electrical machines that form part of the wind power installation, generators and transformers, it is possible to change the impedance of the neutral closure introducing a plurality of active and passive elements. This limits the currents during the grid fault, thereby reducing the peak torque in the mechanical train of the wind turbines and allows guaranteeing compliance with the network connection requirements, as control of the active and reactive currents is maintained at all times.

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.