Abstract: A wind turbine that includes a housing, an asynchronous generator disposed in the housing and configured to be electrically connected to a power grid connection; a power converter circuit disposed in the housing and configured to be electrically connected to the asynchronous generator; and a variable impedance device disposed in the housing, connected to the generator and configured to limit current by varying impedance in response to a transient current. The wind turbine delivers reactive power to the power grid when the variable impedance device varies impedance in response to the transient current. The variable impedance device can be arranged in series between the asynchronous generator and the power grid connection, or can be in a shunt arrangement between the asynchronous generator and a neural point.

Abstract: A wind turbine that includes a housing, an asynchronous generator disposed in the housing and configured to be electrically connected to a power grid connection; a power converter circuit disposed in the housing and configured to be electrically connected to the asynchronous generator; and a variable impedance device disposed in the housing, connected to the generator and configured to limit current by varying impedance in response to a transient current. The wind turbine delivers reactive power to the power grid when the variable impedance device varies impedance in response to the transient current. The variable impedance device can be arranged in series between the asynchronous generator and the power grid connection, or can be in a shunt arrangement between the asynchronous generator and a neural point.

Abstract: Protection system for a power converter connected to a doubly fed induction generator having a rotor and a stator. The power converter includes a grid-side-converter, a machine-side-converter, a DC link between both converters, a chopper connected to the DC link, and a hardware protection system connected to the rotor of the generator. The protection system includes a first control unit for controlling the hardware protection system depending on the voltage in the DC link, a second control unit for controlling the chopper depending on the DC link voltage, and a third control unit for controlling both converters.

Abstract: Protection system for a power converter connected to a doubly fed induction generator having a rotor and a stator. The power converter includes a grid-side-converter, a machine-side-converter, a DC link between both converters, a chopper connected to the DC link, and a hardware protection system connected to the rotor of the generator. The protection system includes a first control unit for controlling the hardware protection system depending on the voltage in the DC link, a second control unit for controlling the chopper depending on the DC link voltage, and a third control unit for controlling both converters.

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 invention controls the network frequency via an active power reserve obtained by interacting in a coordinated manner with the speed regulation that acts on the power generated or on the pitch angle, to guarantee primary or secondary regulation across the whole range of wind speed.

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: The invention comprises a doubly-fed generator (2), the rotor thereof is connected to the power grid (3) by a back-to-back converter (4) and the stator thereof is connected to the power grid (3), essentially standing out for additionally comprising at least one first additional impedance (5) connected in parallel between the generator (2) rotor and the back-to-back converter (4); at least one second additional impedance (6) connected to the generator stator (2); and at least one control unit capable of governing the additional impedances (5, 6).

Abstract: The object of the invention is to provide an energy management system for variable resource energy generating systems, which incorporates means for the storing of energy and the management thereof. The system permits the needs which arise in the power grid to be met, and participates in the regulation of the power grid and contributing to the stability and quality thereof.

Abstract: A power-management system and method for photovoltaic installations connecting to the grid incorporates monitoring active and/or reactive power, account being taken at all times of grid requirements, in order to allow temporary demand arising in the grid to be addressed, thereby contributing to regulation of the grid and to the stability and quality thereof.

Abstract: The present invention discloses a method for controlling a back-to-back converter when disturbances are produced in the grid which limit the capacity of the converter (105) on the side of the grid to control the voltage of the DC stage (106). In that event, the solution proposed is to pass complete or partial responsibility for controlling the voltage of the DC stage (106) to the converter (104) on the side of the generator (103).

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 subject matter of the invention is the provision of a power-management system and method for photovoltaic installations connecting to the grid, which incorporates monitoring active and/or reactive power, account being taken at all times of grid requirements, in order to allow temporary demand arising in the grid to be addressed, thereby contributing to regulation of the grid and to the stability and quality thereof.

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: 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 invention controls the network frequency via an active power reserve obtained by interacting in a coordinated manner with the speed regulation that acts on the power generated or on the pitch angle, to guarantee primary or secondary regulation across the whole range of wind speed.

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.