ES2351901B1

ES2351901B1 - METHOD AND SYSTEM FOR OPERATING AN AIRBRUSHER.

Info

Publication number: ES2351901B1
Application number: ES200803132A
Authority: ES
Inventors: David Sole Lopez; Susana Simon Segura; Javier Perez Barbachano; Jesus Mayor Lusarreta; Jorge Acedo Sanchez; Eneko Olea Oregi; Ainhoa Carcar Mayor; Iker Garmendia Olarreaga; Josu Elorriaga Llanos; Sergio Aurtenetxea Larrinaga; Xabier Calvo Madariaga
Original assignee: Ingeteam Energy SA
Current assignee: Ingeteam Power Technology SA
Priority date: 2008-11-03
Filing date: 2008-11-03
Publication date: 2012-01-16
Anticipated expiration: 2028-11-03
Also published as: ES2351901A1

Abstract

Método y sistema para operar un aerogenerador.#La presente invención se aplica a turbinas eólicas equipadas con generadores asíncronos doblemente alimentados y con al menos un convertidor de potencia con la novedad de que permite, bajo determinadas circunstancias, la operación de la turbina como un sistema FC, como DFIG o como Asíncrono (AS), lo que redunda en una mayor disponibilidad de la turbina.Method and system for operating a wind turbine. # The present invention applies to wind turbines equipped with double-powered asynchronous generators and with at least one power converter with the novelty that it allows, under certain circumstances, the operation of the turbine as a system FC, as DFIG or as Asynchronous (AS), which results in greater turbine availability.

Description

Método y sistema para operar un aerogenerador. Method and system to operate a wind turbine.

Objeto de la invención Object of the invention

La presente invención se aplica a turbinas eólicas equipadas con generadores asíncronos doblemente alimentados y con al menos un convertidor de potencia con la novedad de que permite, bajo determinadas circunstancias, la operación de la turbina como un sistema Full Converter (FC), como doblemente alimentado (DFIG) o como asíncrono (AS), lo que redunda en una mayor disponibilidad de la turbina. The present invention applies to wind turbines equipped with double-powered asynchronous generators and with at least one power converter with the novelty that it allows, under certain circumstances, the operation of the turbine as a Full Converter (FC) system, as doubly fed (DFIG) or as asynchronous (AS), which results in greater turbine availability.

Antecedentes de la invención Background of the invention

En los inicios de la energía eólica, la mayor parte de las turbinas eólicas estaban equipadas con generadores asíncronos de jaula de ardilla. Estas turbinas funcionaban a velocidad de giro prácticamente constante, lo que implicaba menor eﬁciencia en la conversión de la energía del viento y mayores esfuerzos mecánicos en el aerogenerador. En la década de los 90 aparecieron las turbinas eólicas de velocidad variable que están equipadas con generadores asíncronos de rotor bobinado cuyo rotor está alimentado a través de un convertidor de potencia, a este tipo de sistema (entendiendo por sistema el conjunto de generador, convertidor de potencia y elementos de maniobra), se le conoce como doblemente alimentado (DFIG -Doubly Fed Induction Generator), ya que precisan de un convertidor de potencia encargado de gestionar la energía de los devanados rotóricos. Este sistema presenta la ventaja de mayor eﬁciencia energética y menores esfuerzos mecánicos por lo que se ha convertido en uno de los sistemas dominantes. At the beginning of wind power, most of the wind turbines were equipped with asynchronous squirrel cage generators. These turbines were operating at a practically constant speed of rotation, which implied less efficiency in wind energy conversion and greater mechanical stress on the wind turbine. In the decade of the 90 appeared the wind turbines of variable speed that are equipped with asynchronous generators of winding rotor whose rotor is fed through a power converter, to this type of system (understanding by system the set of generator, converter of power and maneuvering elements), it is known as doubly fed (DFIG -Doubly Fed Induction Generator), since they require a power converter responsible for managing the energy of the rotary windings. This system has the advantage of greater energy efficiency and less mechanical efforts, which is why it has become one of the dominant systems.

Con el mismo objetivo aparecieron las turbinas eólicas de velocidad variable con generadores aislados de la red mediante un convertidor de potencia conectado al estátor del generador, que permite entregar a la red la potencia generada por la turbina. A este tipo de sistema se le conoce como Full Converter (FC), ya que precisan de un convertidor de potencia encargado de gestionar la energía de los devanados estatóricos. With the same objective, variable speed wind turbines appeared with generators isolated from the grid by means of a power converter connected to the generator stator, which allows the power generated by the turbine to be delivered to the grid. This type of system is known as Full Converter (FC), since they require a power converter responsible for managing the energy of the static windings.

A medida que la capacidad eólica instalada y la potencia unitaria de las turbinas eólicas aumenta, se hace más importante asegurar la disponibilidad y ﬁabilidad de este tipo de generación eléctrica. As the installed wind capacity and the unit power of the wind turbines increases, it becomes more important to ensure the availability and reliability of this type of power generation.

La presente invención se aplica a turbinas eólicas equipadas con generadores asíncronos doblemente alimentados y con al menos un convertidor de potencia con la novedad de que permite, bajo determinadas circunstancias, la operación de la turbina como un sistema FC, como DFIG o como Asíncrono (AS), lo que redunda en una mayor disponibilidad de la turbina. The present invention applies to wind turbines equipped with double-powered asynchronous generators and with at least one power converter with the novelty that it allows, under certain circumstances, the operation of the turbine as an FC system, as DFIG or as Asynchronous (AS ), which results in greater turbine availability.

Adicionalmente la naturaleza inherentemente distribuida de la energía eólica provoca que no siempre se puedan asegurar tiempos de reacción y reparación de anomalías, tan breves como sería deseable. Este caso se pone especialmente de maniﬁesto en las turbinas eólicas marinas (offshore) en las que por distintas causas la accesibilidad puede verse reducida. Additionally, the inherently distributed nature of wind energy means that it is not always possible to ensure reaction times and repair of anomalies, as short as would be desirable. This case is especially evident in offshore wind turbines in which for different reasons accessibility can be reduced.

La presente invención soluciona la problemática anterior al proporcionar tolerancia ante anomalías en el convertidor de potencia y otros componentes del sistema de forma que permite una selección entre los modos de operación FC, DFIG o AS. The present invention solves the above problem by providing tolerance to anomalies in the power converter and other components of the system so as to allow a selection between FC, DFIG or AS modes of operation.

En el estado del arte actual encontramos invenciones cuya ﬁnalidad es evitar la pérdida de disponibilidad en las turbinas eólicas debida a fallos de funcionamiento en los componentes del sistema, o protegerlos cuando puedan llegar a producirse condiciones críticas de funcionamiento en las que peligre la integridad de los propios componentes (por ejemplo, del convertidor de potencia). In the current state of the art we find inventions whose purpose is to avoid the loss of availability in wind turbines due to malfunctions in the system components, or to protect them when critical operating conditions may occur in which the integrity of the own components (for example, of the power converter).

La solicitud de patente US20060214428A1 (Jens Altemark, et al., Repower Systems AG) describe un método para conectar en paralelo convertidores de potencia de manera que ante un fallo de uno de ellos los demás puedan seguir funcionando evitando así la parada de la turbina eólica, funcionando siempre en modo DFIG. The patent application US20060214428A1 (Jens Altemark, et al., Repower Systems AG) describes a method to connect power converters in parallel so that in the event of a failure of one of them the others can continue to work thus preventing the wind turbine from stopping , always operating in DFIG mode.

La solicitud de patente EP1768223A2 (José I. Llorente, et al., Gamesa Innovation & Technology, S.L. Unipersonal) describe una topología de convertidores de potencia colocados en paralelo y que atacan a diferentes bobinados del generador cuyo objeto es aumentar la eﬁciencia de la conversión y tolerar el fallo de alguno de los convertidores de potencia funcionando siempre en modo FC, de este modo, si uno de los convertidores falla se sigue generando potencia pero nunca se alcanzará la potencia nominal. Patent application EP1768223A2 (José I. Llorente, et al., Gamesa Innovation & Technology, SL Unipersonal) describes a topology of power converters placed in parallel and attacking different windings of the generator whose purpose is to increase the efficiency of the conversion and tolerate the failure of any of the power converters always operating in FC mode, thus, if one of the converters fails, power is still generated but the nominal power will never be reached.

La solicitud de patente US20060227578A1 (Rajib Data, et al., General Electric Company) describe una pluralidad de convertidores colocados en paralelo y cuya salida se compone de un transformador con varios devanados conectados en serie. Esta propuesta, al igual que las anteriores, aumenta la tolerancia ante fallos del convertidor mediante el empleo de una pluralidad de convertidores. Patent application US20060227578A1 (Rajib Data, et al., General Electric Company) describes a plurality of converters placed in parallel and whose output consists of a transformer with several windings connected in series. This proposal, like the previous ones, increases the fault tolerance of the converter by employing a plurality of converters.

La solicitud de patente US20070024059A1 (John Douglas D’Atre, et al. General Electric Company) describe la posibilidad de activar los semiconductores del convertidor de potencia en un modo de cortocircuito, de forma que se impide el paso de energía a través del convertidor evitando, por ejemplo, un ﬂujo excesivo de potencia que pudiera llegar a dañarlo. No obstante, no permite la operación de la turbina en caso de no tener operativo el convertidor. Dicha situación puede producirse por ejemplo si fallan los semiconductores de la electrónica de potencia o si falla la electrónica de control del convertidor. Patent application US20070024059A1 (John Douglas D'Atre, et al. General Electric Company) describes the possibility of activating the semiconductors of the power converter in a short-circuit mode, so as to prevent the passage of energy through the converter avoiding , for example, an excessive ﬂ ow of power that could damage it. However, it does not allow turbine operation if the converter is not operational. Such a situation can occur, for example, if the semiconductors of the power electronics fail or if the control electronics of the converter fail.

La patente US7012409B2 (SEMIKRON) describe un sistema en el que a través de un convertidor de potencia auxiliar es posible, ante contingencias de la red, controlar la potencia reactiva aportada y consumida de la red. US7012409B2 (SEMIKRON) describes a system in which, through an auxiliary power converter, it is possible, in the event of network contingencies, to control the reactive power supplied and consumed from the network.

La solicitud de patente WO2008/026973A1 (Gertmar et al., ABB) describe un método de operación en el que el generador asíncrono se conecta directamente a la red, o a través de un convertidor de potencia, con el objetivo de optimizar la producción para diferentes velocidades de giro. Patent application WO2008 / 026973A1 (Gertmar et al., ABB) describes a method of operation in which the asynchronous generator is connected directly to the network, or through a power converter, in order to optimize production for different turning speeds

Actualmente, aquellos fallos en el aerogenerador que provocan un comportamiento anómalo del convertidor de potencia implican la pérdida, total o parcial, de generación de energía hasta que sea solventado el fallo. Currently, those failures in the wind turbine that cause an abnormal behavior of the power converter imply the loss, total or partial, of power generation until the fault is resolved.

La presente invención evita colocar convertidores de potencia redundantes, y asegura modos de operación alternativos para seguir generando hasta el 100% de la potencia nominal. The present invention avoids placing redundant power converters, and ensures alternative modes of operation to continue generating up to 100% of the nominal power.

Descripción de la invención Description of the invention

Para conseguir los objetivos y resolver los inconvenientes anteriormente indicados, la invención consiste en un nuevo sistema de generación eléctrica diseñado de tal manera que permite el cambio entre los modos de operación FC, DFIG, y AS, permitiendo, en una realización preferida, funcionar hasta el 100 por 100 de la potencia nominal en alguno de los diferentes modos de operación en que puede funcionar sin que éste tenga elementos redundantes. In order to achieve the objectives and solve the aforementioned drawbacks, the invention consists of a new power generation system designed in such a way that it allows the switching between the operating modes FC, DFIG, and AS, allowing, in a preferred embodiment, to operate up to 100 percent of the nominal power in any of the different modes of operation in which it can operate without it having redundant elements.

Se entiende por potencia nominal, la potencia característica máxima de cada uno de los modos de operación (FC -DFIG -AS). Nominal power is understood as the maximum characteristic power of each of the operating modes (FC -DFIG -AS).

Además son conocidos los siguientes modos de operación: In addition, the following modes of operation are known:

--: modo de operación FC, en el que se cortocircuita el bobinado del rotor del generador y el estátor se conecta a la red a través de al menos un convertidor de potencia; FC mode of operation, in which the generator rotor winding is short-circuited and the stator is connected to the grid through at least one power converter;

--: modo de operación DFIG, en el que el bobinado del rotor del generador se conecta a la red a través de al menos un convertidor de potencia y el estátor se conecta directamente a la red; DFIG mode of operation, in which the generator rotor winding is connected to the network through at least one power converter and the stator is connected directly to the network;

--: modo de operación AS, en el que se cortocircuita el bobinado del rotor del generador y el estátor se conecta directamente a la red. AS mode of operation, in which the generator rotor winding is short-circuited and the stator is connected directly to the grid.

Se entiende como falta de operatividad parcial cualquier fallo de al menos un componente del sistema que impida funcionar generando el 100 por 100 de la potencia nominal en un modo de operación. La solución propuesta en esta invención permite generar hasta el 100 por 100 de la potencia nominal en al menos uno de los otros dos modos de operación. Partial lack of operability is understood as any failure of at least one component of the system that prevents operation by generating 100 percent of the nominal power in an operating mode. The solution proposed in this invention allows generating up to 100 percent of the nominal power in at least one of the other two modes of operation.

En una realización preferida de la invención, las condiciones de entrada y salida a cada uno de los modos de operación son: -falta de operatividad parcial del sistema, -falta de operatividad total de los convertidores de potencia del sistema, -especiﬁcación del operador de red eléctrica, -especiﬁcación del controlador general de parque eólico, -criterios de optimización de rendimiento. -reserva de potencia activa requerida por el controlador de la turbina eólica, -aumento de disponibilidad durante labores de mantenimiento, -o cualquier combinación de las anteriores. Adicionalmente, en función de las condiciones de entrada, la invención permite seleccionar el modo de operación que maximice la generación de potencia del aerogenerador. In a preferred embodiment of the invention, the conditions of entry and exit to each of the modes of operation are: - lack of partial operability of the system, - lack of total operability of the power converters of the system, - specification of the operator of power grid, -specification of the general wind farm controller, -performance optimization criteria. - active power reserve required by the wind turbine controller, - increased availability during maintenance work, - or any combination of the above. Additionally, depending on the input conditions, the invention allows selecting the mode of operation that maximizes the generation of wind turbine power.

El método de la invención precisa del empleo de los siguientes componentes: al menos un generador asíncrono de rotor bobinado con al menos un estátor eléctricamente independiente, al menos un convertidor de potencia con capacidad de controlar las corrientes rotóricas y/o estatóricas de dicho generador en amplitud, frecuencia y fase, y un conjunto de elementos de maniobra que permitan la conexión y desconexión de los componentes anteriores. Dicho método se caracteriza porque comprende operar según un modo de operación seleccionado entre FC, DFIG y AS. The method of the invention requires the use of the following components: at least one asynchronous winding rotor generator with at least one electrically independent stator, at least one power converter capable of controlling the rotational and / or static currents of said generator in amplitude, frequency and phase, and a set of maneuvering elements that allow the connection and disconnection of the previous components. Said method is characterized in that it comprises operating according to a mode of operation selected from FC, DFIG and AS.

Se entiende por convertidor de potencia cualquier topología que emplee electrónica de potencia y el control asociado. Dichos elementos constituyen una unidad funcional encargada de controlar las magnitudes rotóricas y/o estatóricas, tales como las corrientes, de tal manera que permita entregar energía a la red eléctrica, funcionando a velocidad variable o ﬁja. El convertidor de potencia puede ser una topología formada por uno o varios back-to-back (conversiones de AC -DC -AC reversibles, a través de un bus de continua, donde AC es corriente alterna y DC corriente continua) o cualquier otra topología que realice la funcionalidad comentada. Power converter means any topology that uses power electronics and the associated control. These elements constitute a functional unit in charge of controlling the rotational and / or static magnitudes, such as currents, in such a way that it allows energy to be delivered to the electricity grid, operating at a fixed or fixed speed. The power converter can be a topology formed by one or several back-to-backs (reversible AC-DC -AC conversions, through a continuous bus, where AC is alternating current and DC direct current) or any other topology that performs the functionality mentioned.

El diseño del generador asíncrono de rotor bobinado tiene las siguientes características: The asynchronous winding rotor generator design has the following characteristics:

--: Un estátor formado por al menos un sistema eléctricamente independiente. A stator formed by at least one electrically independent system.

--: Elementos de maniobra capaces de modiﬁcar la conﬁguración de su rotor, de manera que permiten cortocircuitarlo y aislarlo del convertidor de potencia, o conectarlo al convertidor de potencia. El cortocircuitado del rotor del generador en el modo de funcionamiento DFIG es posible realizarlo mediante el cortocircuito franco o a través de otros elementos tales como resistencias, inductancias, condensadores, tiristores, IGBTs, diodos, o cualquier combinación de los elementos anteriores. Maneuvering elements capable of modifying the configuration of its rotor, so that it can be short-circuited and isolated from the power converter, or connected to the power converter. The short-circuit of the generator rotor in the DFIG mode of operation is possible by means of frank short-circuiting or other elements such as resistors, inductances, capacitors, thyristors, IGBTs, diodes, or any combination of the previous elements.

La presente invención tiene como objeto poder seleccionar y cambiar entre los tres modos de operación FC, DFIG y AS, para maximizar la potencia generada por la turbina eólica, pudiendo llegar a ser hasta del 100% de la potencia nominal en el modo de operación seleccionado incluso en condiciones de falta de operatividad parcial. The present invention aims to be able to select and change between the three modes of operation FC, DFIG and AS, to maximize the power generated by the wind turbine, being able to be up to 100% of the nominal power in the selected mode of operation even in conditions of lack of partial operability.

Para conseguir la funcionalidad comentada, el procedimiento de la invención comprende las siguientes fases: To achieve the functionality mentioned, the process of the invention comprises the following phases:

--: detectar unas condiciones de salida del modo de operación actual, detect output conditions of the current operating mode,

--: detectar unas condiciones de entrada a al menos un modo de operación distinto del modo de operación actual, detect input conditions to at least one operating mode other than the current operating mode,

--: seleccionar el modo de operación distinto del modo de operación actual, select the operating mode other than the current operating mode,

--: funcionar en el modo de operación seleccionado, actuando sobre unos elementos de maniobra. operate in the selected operating mode, acting on some maneuvering elements.

El método de operación para cambiar del modo FC al modo DFIG y una vez funcionando en DFIG, volver a pasar al modo FC, comprende las siguientes fases: The method of operation to change from FC mode to DFIG mode and once operating in DFIG, switch back to FC mode, comprises the following phases:

--: detectar al menos una condición de salida del modo FC (p.ej. fallo parcial de algún elemento del sistema), detect at least one condition of FC mode output (eg partial failure of some system element),

--: desconectar, a través de la actuación de unos elementos de maniobra, el estátor del generador de los convertidores a los que esté conectado, y desconectar los convertidores de potencia de la red. Desconectar el cortocircuito de rotor (establecido en el modo de funcionamiento FC) para conectar, a través de los elementos de maniobra el rotor del generador a al menos un convertidor de potencia que no esté en situación de falta de operatividad parcial, para funcionar en modo DFIG, disconnect, through the actuation of some maneuvering elements, the generator stator of the converters to which it is connected, and disconnect the power converters from the network. Disconnect the rotor short circuit (established in FC operating mode) to connect, through the operating elements, the generator rotor to at least one power converter that is not in a situation of partial lack of operability, to operate in mode DFIG,

--: operar el generador en modo DFIG realizando las adaptaciones necesarias para permitir su acoplamiento a la red, operate the generator in DFIG mode making the necessary adaptations to allow its coupling to the network,

--: conectar el estátor a la red para generar potencia, connect the stator to the network to generate power,

--: detectar las condiciones de entrada al modo FC y cuando se cumplan estas condiciones, actuar sobre los elementos de maniobra para desconectar el sistema de la red y proceder a la activación del modo de operación FC. detect the conditions for entering FC mode and when these conditions are met, act on the operating elements to disconnect the system from the network and proceed to the activation of the FC operating mode.

El método de operación para cambiar del modo FC al modo AS, y una vez funcionando en el modo AS pasar al FC o al DFIG, comprende las siguientes fases: The method of operation to change from FC mode to AS mode, and once operating in AS mode, switch to FC or DFIG, comprises the following phases:

--: detectar al menos una condición de salida del modo FC, detect at least one output condition of FC mode,

--: desconectar, si previamente está conectado y actuando sobre unos elementos de maniobra, el estátor del generador de los convertidores a los que esté conectado y desconectar los convertidores de la red. disconnect, if previously connected and acting on operating elements, the generator stator of the converters to which it is connected and disconnect the converters from the network.

--: operar el generador en modo AS realizando las adaptaciones necesarias para permitir su acoplamiento a la red y la generación de potencia, operate the generator in AS mode by making the necessary adaptations to allow its coupling to the grid and power generation,

--: detectar las condiciones de entrada al modo DFIG y cuando se cumplan estas condiciones, actuar sobre los elementos de maniobra para desconectar el sistema de la red y proceder a la activación del modo de operación DFIG, o detectar las condiciones de entrada al modo FC y cuando se cumplan estas condiciones actuar sobre los elementos de maniobra para desconectar el sistema de la red y proceder a la activación del modo de operación FC. detect the conditions of entry to DFIG mode and when these conditions are met, act on the operating elements to disconnect the system from the network and proceed to the activation of the DFIG mode of operation, or detect the conditions of entry to FC mode and when If these conditions are met, act on the operating elements to disconnect the system from the network and proceed to the activation of the FC operating mode.

El método de operación para cambiar del modo DFIG al modo AS, y una vez funcionando en el modo AS pasar al FC o al DFIG, comprende las siguientes fases: The method of operation to change from DFIG mode to AS mode, and once operating in AS mode, switch to FC or DFIG, comprises the following phases:

--: detectar al menos una condición de salida del modo DFIG, detect at least one output condition of DFIG mode,

--: desconectar, si previamente está conectado y actuando sobre unos elementos de maniobra, el estátor del generador de la red. A través de los elementos de maniobra, desconectar los convertidores de potencia del rotor del generador y de la red, para funcionar en modo AS, disconnect, if previously connected and acting on operating elements, the stator of the network generator. Through the operating elements, disconnect the power converters from the generator rotor and from the grid, to operate in AS mode,

--: actuar sobre unos elementos de maniobra, para cortocircuitar el rotor del generador, act on some maneuvering elements, to short-circuit the generator rotor,

--: detectar las condiciones de entrada al modo DFIG y cuando se cumplan estas condiciones actuar sobre los elementos de maniobra para desconectar el sistema de la red y proceder a la activación del modo de operación DFIG, o detectar las condiciones de entrada al modo FC y cuando se cumplan estas condiciones actuar sobre los elementos de maniobra para desconectar el sistema de la red y proceder a la activación del modo de operación FC. detect the conditions of entry to DFIG mode and when these conditions are met act on the operating elements to disconnect the system from the network and proceed to the activation of the DFIG mode of operation, or detect the conditions of entry to FC mode and when fulfill these conditions act on the maneuver elements to disconnect the system from the network and proceed to the activation of the FC mode of operation.

En consecuencia, para implantar el método anterior el sistema incluye, además de los elementos necesarios para el control del aerogenerador: Consequently, to implement the previous method, the system includes, in addition to the necessary elements for the control of the wind turbine:

--: elementos de maniobra para conectar/desconectar el convertidor de potencia del estátor del generador, del rotor del generador, y de la red, operating elements for connecting / disconnecting the power converter from the generator stator, the generator rotor, and the network,

--: elementos de maniobra para conectar/desconectar el estátor del generador de la red, operating elements to connect / disconnect the generator stator from the network,

--: elementos de maniobra para cortocircuitar el rotor del generador constituidos por una pluralidad de elementos seleccionados entre elementos activos, elementos pasivos y combinación de los mismos. Se entiende por elementos activos aquellos que se pueden maniobrar de manera automática (tales como, contactores, interruptores de estado sólido) y por elementos pasivos aquellos que no se pueden maniobrar (por ejemplo, resistencias, inductancias, capacidades). maneuvering elements to short-circuit the generator rotor consisting of a plurality of elements selected from active elements, passive elements and combination thereof. Active elements are those that can be maneuvered automatically (such as contactors, solid state switches) and passive elements are those that cannot be maneuvered (for example, resistors, inductances, capacities).

Además de los elementos anteriores, en una realización preferida de la invención se incluyen medios convencionales para reducir el pico de corriente asociado al acoplamiento de un generador asíncrono (rotor cortocircuitado) como por ejemplo arrancadores suaves (soft starter). In addition to the above elements, in a preferred embodiment of the invention conventional means are included to reduce the peak of current associated with the coupling of an asynchronous generator (short-circuited rotor) such as soft starters.

El método anteriormente descrito se puede ejecutar mediante elementos de maniobra tanto dependientes como independientes del convertidor. Se entiende por elementos dependientes del convertidor la electrónica de potencia y elementos de maniobra asociados a él. Se entiende por elementos independientes del convertidor la electrónica de potencia y elementos de maniobra no asociados a él. The method described above can be executed by operating elements both dependent and independent of the converter. It is understood by elements dependent on the converter the power electronics and operating elements associated with it. Independent elements of the converter are understood as power electronics and operating elements not associated with it.

El método también permite la posibilidad de controlar la resistencia rotórica cortocircuitando el rotor del generador mediante el cortocircuito franco o a través de otros elementos tales como resistencias, inductancias, condensadores, tiristores, IGBTs, diodos, o cualquier combinación de los elementos anteriores. The method also allows the possibility of controlling the rotational resistance by short-circuiting the generator rotor by means of frank short-circuiting or through other elements such as resistors, inductances, capacitors, thyristors, IGBTs, diodes, or any combination of the previous elements.

Aquellos convertidores o componentes del convertidor no encargados del control del generador, siempre que se encuentren operativos, pueden ser utilizados para la generación de potencia reactiva. Those converters or converter components not responsible for generator control, provided they are operational, can be used for the generation of reactive power.

A continuación para facilitar una mejor comprensión de esta memoria descriptiva y formando parte integrante de la misma, se acompañan una serie de ﬁguras en las que con carácter ilustrativo y no limitativo se ha representado el objeto de la invención. Next, in order to facilitate a better understanding of this descriptive report and forming an integral part thereof, a series of ﬁ gures are attached in which the object of the invention has been represented by way of illustration and not limitation.

Breve descripción de las ﬁguras Brief description of the ﬁ gures

Figura 1.-Muestra un esquema general del sistema de acuerdo a una realización preferida de la invención. Figure 1.- Shows a general scheme of the system according to a preferred embodiment of the invention.

Figura 2.-Muestra un esquema general del sistema de acuerdo a una realización preferida de la invención que incluye n convertidores de potencia. Figure 2.- Shows a general scheme of the system according to a preferred embodiment of the invention that includes n power converters.

Figura 3. -Muestra un esquema general del sistema funcionando en el modo de operación FC. Figure 3. - Shows a general scheme of the system operating in the FC mode of operation.

Figura 4. -Muestra un esquema general del sistema funcionando en el modo de operación DFIG. Figure 4. - Shows a general scheme of the system operating in DFIG mode of operation.

Figura 5.-Muestra un esquema general del sistema funcionando en el modo de operación AS. Figure 5.- Shows a general scheme of the system operating in the AS operating mode.

Figura 6.-Muestra un esquema general del sistema de acuerdo a una realización preferida de la invención donde parte de los convertidores de potencia se destinan al control del generador y otros convertidores, no encargados del control del generador, se destinan al control de potencia reactiva entregada directamente a la red. Figure 6.- Shows a general scheme of the system according to a preferred embodiment of the invention where part of the power converters are intended for the control of the generator and other converters, not responsible for the control of the generator, are intended for the control of reactive power delivered directly to the network.

Descripción de la forma de realización preferida Description of the preferred embodiment

A continuación se realiza una descripción de la invención basada en las ﬁguras anteriormente comentadas. A description of the invention based on the aforementioned figures is made below.

El método de la invención comprende operar el sistema según un modo de operación seleccionado entre FC, DFIG y AS. The method of the invention comprises operating the system according to a mode of operation selected from FC, DFIG and AS.

El cambio del modo de operación se realiza cuando el sistema está desconectado de la red y sin generar potencia, mediante los diferentes elementos de maniobra y mediante la modiﬁcación del control del sistema eléctrico. The change of the operating mode is carried out when the system is disconnected from the network and without generating power, by means of the different maneuvering elements and by modifying the control of the electrical system.

En el cambio a cualquiera de los tres modos de operación es necesario adaptar el funcionamiento de los diferentes subsistemas del aerogenerador como, por ejemplo, control de pitch, control de yaw, curva de potencia, control de convertidores de potencia, entre otros. When switching to any of the three modes of operation, it is necessary to adapt the operation of the different wind turbine subsystems, such as pitch control, yaw control, power curve, power converter control, among others.

A continuación se describen las diferentes formas de actuar según el caso particular representado en la ﬁgura 1 donde el sistema comprende dos convertidores de potencia (101) y (102) y un generador (110). The different ways of acting according to the particular case represented in Figure 1 are described below, where the system comprises two power converters (101) and (102) and a generator (110).

En el modo de operación FC (Figura 3), se representa la turbina eólica actuando como un sistema FC por lo que el elemento de maniobra 105 deberá estar cerrado cortocircuitando el rotor (113) del generador; el rotor está eléctricamente aislado mediante los elementos de maniobra 104 y 106 abiertos. Toda la potencia del generador se evacúa a través de los elementos de maniobra 109 y 107 conectados a los convertidores de potencia. Los convertidores de potencia están conectados a la red mediante los elementos 103 y 108 (cerrados). La conexión a la red se puede realizar directamenteoatravés de un transformador (114). In the FC operating mode (Figure 3), the wind turbine is represented acting as an FC system so the operating element 105 must be closed by short-circuiting the rotor (113) of the generator; The rotor is electrically insulated by the open control elements 104 and 106. All generator power is evacuated through operating elements 109 and 107 connected to power converters. The power converters are connected to the network via elements 103 and 108 (closed). The connection to the network can be made directly through a transformer (114).

En caso de fallo de uno de los convertidores de potencia (101, 102), se pasa al modo de operación DFIG (Figura 4), para funcionar en el modo DFIG. A pesar de haber habido un fallo en el sistema, con este nuevo modo de operación se puede llegar a trabajar hasta al 100% de la potencia nominal. In case of failure of one of the power converters (101, 102), it is switched to DFIG mode of operation (Figure 4), to operate in DFIG mode. Despite the failure of the system, with this new mode of operation it is possible to work up to 100% of the nominal power.

En caso de fallo del convertidor de potencia (101) y que no pueda ser utilizado para el control del generador, se procede al cambio de conﬁguración del modo de operación FC al modo de operación DFIG. El proceso comienza por aislar el convertidor de potencia (101) o una parte del mismo (101a y/o 101b) en la que se ha producido un fallo abriendo los elementos de maniobra (109 y/o 103 y 104). Para funcionar como generador asíncrono doblemente alimentado se conecta el convertidor de potencia (102) al rotor (113) del generador (110), elemento de maniobra 107 abierto, elemento de maniobra 106 cerrado, y el elemento de maniobra 105 abierto para deshacer el cortocircuito del rotor del generador. Por último, para evacuar la potencia estatórica generada en el modo DFIG los elementos de maniobra (100 y 111) están cerrados. En el caso de que el convertidor de potencia (101) esté inhabilitado para el funcionamiento en el modo FC y alguno de sus componentes (101a o 101b) esté operativo, éste podrá ser utilizado para la generación de potencia reactiva. Se procede al cierre del elemento de maniobra (109) en caso de fallo de la parte 101b (estando el 101a operativo) o del cierre del elemento de maniobra (103) en caso de fallo de la parte (101a) (estando el 101b operativo). In case of failure of the power converter (101) and which cannot be used for generator control, the configuration of the FC operating mode is changed to the DFIG operating mode. The process begins by isolating the power converter (101) or a part thereof (101a and / or 101b) in which a fault has occurred opening the operating elements (109 and / or 103 and 104). To function as a double-powered asynchronous generator, the power converter (102) is connected to the rotor (113) of the generator (110), operating element 107 open, operating element 106 closed, and operating element 105 open to undo the short circuit of the generator rotor. Finally, to evacuate the static power generated in DFIG mode the operating elements (100 and 111) are closed. In the event that the power converter (101) is disabled for operation in FC mode and any of its components (101a or 101b) is operational, it may be used for the generation of reactive power. The maneuver element (109) is closed in case of failure of part 101b (the 101st being operational) or the closure of the maneuver element (103) in case of failure of the part (101a) (the 101b being operative ).

En caso de fallo del convertidor de potencia (101) y del convertidor de potencia (102), se procede al cambio de conﬁguración del modo de operación DFIG al modo de operación AS (Figura 5). El proceso comienza por aislar los dos convertidores de potencia en fallo (101a y/o 101b) y (102a y/o 102b), con los elementos de maniobra (104 y 106) abiertos, y los elementos de maniobra necesarios para aislar la parte del convertidor en fallo (109, 103, 107 y 108). Para funcionar como generador asíncrono directamente conectado a la red, el rotor (113) del generador (110) se cortocircuita con el elemento de maniobra (105) cerrado. Por último, para evacuar la potencia estatórica generada, los elementos de maniobra (100 y 111) están cerrados. En este caso, en el que fallan todos los convertidores de potencia, el sistema puede seguir trabajando hasta al 100% de la potencia nominal del modo de funcionamiento AS. En el caso de que alguno de los componentes de los convertidores de potencia (101a, 101b, 102a, 102b) estén operativos, éstos podrán ser utilizados para la generación de potencia reactiva. Se procede, de forma similar al caso anterior, realizando la apertura de los elementos de maniobra de los componentes en fallo y el cierre de los elementos de maniobra correspondientes a los componentes que están operativos. In case of failure of the power converter (101) and the power converter (102), the configuration of the DFIG operating mode to the AS operating mode is changed (Figure 5). The process begins by isolating the two power converters in failure (101a and / or 101b) and (102a and / or 102b), with the operating elements (104 and 106) open, and the necessary operating elements to isolate the part of the converter in failure (109, 103, 107 and 108). To function as an asynchronous generator directly connected to the network, the rotor (113) of the generator (110) is short-circuited with the operating element (105) closed. Finally, to evacuate the generated static power, the maneuvering elements (100 and 111) are closed. In this case, in which all power converters fail, the system can continue working up to 100% of the nominal power of the AS operating mode. In the event that any of the components of the power converters (101a, 101b, 102a, 102b) are operational, they may be used for the generation of reactive power. Proceed, similar to the previous case, by opening the operating elements of the components in failure and closing the operating elements corresponding to the components that are operational.

En otra realización preferida de la invención (Figura 2), se dispone de un sistema con “n” convertidores de potencia (en la Figura 6 se particulariza paran=6convertidores) que permite: In another preferred embodiment of the invention (Figure 2), there is a system with "n" power converters (in Figure 6, paran = 6 converters are particularized) which allows:

1.-Seleccionar el modo de operación. 1.-Select the mode of operation.

2.-Dentro del mismo modo de operación, en aquellas condiciones en las que la potencia extraíble es inferior a la potencia nominal, seleccionar los elementos que han de estar activos y no activos y la carga a la que trabajan. 2.-Within the same mode of operation, in those conditions in which the removable power is lower than the nominal power, select the elements that must be active and non-active and the load at which they work.

3.-Dentro del mismo modo de operación, seleccionar los convertidores de potencia destinados al control del generador, y seleccionar los convertidores, o sus componentes, no encargados del control del generador, destinados a la generación de la potencia reactiva inyectada a la red directamente. 3.-Within the same mode of operation, select the power converters intended for the control of the generator, and select the converters, or their components, not responsible for the control of the generator, intended for the generation of the reactive power injected directly into the network .

En la Figura 6 se presenta el caso particular del sistema funcionando en el modo de operación DFIG, en el que: Figure 6 shows the particular case of the system operating in the DFIG mode of operation, in which:

--: los convertidores (601, 602, 603 y 606b) funcionan correctamente, the converters (601, 602, 603 and 606b) work correctly,

--: los convertidores (604 y 605) presentan falta de operatividad parcial, the converters (604 and 605) have a lack of partial operability,

--: el convertidor (606a) funciona correctamente pero se encuentra desconectado. The converter (606a) works correctly but is disconnected.

Claims

1. one.: Método para operar un aerogenerador que incluye al menos un generador asíncrono de rotor bobinado con al menos un estátor eléctricamente independiente; al menos un convertidor de potencia con capacidad de controlar las corrientes del generador seleccionadas entre rotóricas, estatóricas y combinación de las mismas en amplitud, frecuencia y fase; caracterizado porque comprende operar el sistema según un modo de operación seleccionado entre Full Converter (FC), doblemente alimentado (DFIG), y asíncrono (AS), mediante un conjunto de elementos de maniobra. Method for operating a wind turbine that includes at least one asynchronous winding rotor generator with at least one electrically independent stator; at least one power converter with the ability to control the generator currents selected from rotary, static and combination thereof in amplitude, frequency and phase; characterized in that it comprises operating the system according to an operating mode selected from Full Converter (FC), doubly powered (DFIG), and asynchronous (AS), by means of a set of operating elements.

2. 2.: Método para operar un aerogenerador según reivindicación 1, caracterizado porque comprende las siguientes fases: -detectar unas condiciones de salida del modo de operación actual, -detectar unas condiciones de entrada a al menos un modo de operación distinto del modo de operación actual, Method for operating a wind turbine according to claim 1, characterized in that it comprises the following phases: -detecting exit conditions of the current operating mode, -detecting entry conditions to at least one operating mode other than the current operating mode,

-select the operating mode other than the current operating mode, - operate in the selected operating mode, acting on some maneuvering elements.

3. 3.: Método para operar un aerogenerador según reivindicación 1, caracterizado porque el cambio del modo de operación FC al modo de operación DFIG comprende las siguientes fases: -detectar al menos una condición de salida del modo FC, -detectar las condiciones de entrada al modo DFIG, Method for operating a wind turbine according to claim 1, characterized in that the change from the operating mode FC to the operating mode DFIG comprises the following phases: - detecting at least one output condition of the FC mode, - detecting the input conditions to the DFIG mode,

--: desconectar el estátor del generador de los convertidores de potencia a los que esté conectado, desconectar los convertidores de potencia de la red, desconectar el cortocircuito de rotor, y conectar el rotor del generador a al menos un convertidor de potencia que no esté en situación de falta de operatividad parcial, actuando sobre unos elementos de maniobra, para funcionar en modo DFIG, disconnect the generator stator from the power converters to which it is connected, disconnect the power converters from the mains, disconnect the rotor short circuit, and connect the generator rotor to at least one power converter that is not in a situation of lack of partial operability, acting on some maneuvering elements, to operate in DFIG mode,

--: operar el generador en modo DFIG realizando las adaptaciones necesarias para el modo DFIG, para acoplar el generador a la red y generar potencia, -conectar el estátor a la red para generar potencia, -detectar las condiciones de entrada al modo FC y activación de dicho modo cuando se cumplan las mismas. operate the generator in DFIG mode making the necessary adaptations for DFIG mode, to couple the generator to the network and generate power, -connect the stator to the network to generate power, -detect the conditions of entry to FC mode and activation of said mode when they are met.

4. Four.: Método para operar un aerogenerador según reivindicación 1, caracterizado porque el cambio del modo de operación FC a AS comprende las siguientes fases: -detectar al menos una condición de salida del modo FC, -detectar las condiciones de entrada al modo AS, -desconectar, el estátor del generador de los convertidores de potencia a los que esté conectado y desconectar los convertidores de potencia de la red, actuando sobre unos elementos de maniobra, -operar el generador en modo AS realizando las adaptaciones necesarias para el modo AS, para acoplar el generador a la red y generar potencia, -conectar el estátor a la red para generar potencia, Method for operating a wind turbine according to claim 1, characterized in that the change of the operating mode FC to AS comprises the following phases: - detecting at least one output condition of the FC mode, - detecting the input conditions to the AS mode, - disconnecting, the generator stator of the power converters to which it is connected and disconnecting the power converters from the network, acting on some maneuvering elements, -operate the generator in AS mode making the necessary adaptations for the AS mode, to couple the generator to the network and generate power, - connect the stator to the network to generate power,

-detect the input conditions to the selected mode between DFIG and FC, and activate the selected mode when they are met.

5. 5.: Método para operar un aerogenerador según reivindicación 1, caracterizado porque el cambio del modo de operación DFIG a AS comprende las siguientes fases: -detectar al menos una condición de salida del modo DFIG, -detectar las condiciones de entrada al modo AS, -desconectar el estátor del generador de la red, desconectar los convertidores de potencia del rotor del generador Method for operating a wind turbine according to claim 1, characterized in that the change of the DFIG operating mode to AS comprises the following phases: -detecting at least one output condition from DFIG mode, -detecting the input conditions to AS mode, -disconnecting the generator stator from the mains, disconnect the power converters from the generator rotor

and of the network, acting on some maneuvering elements, to operate in AS mode, -shorting the generator rotor, acting on some maneuvering elements,

--: operar el generador en modo AS realizando las adaptaciones necesarias para el modo AS, para acoplar el generador a la red y generar potencia, operate the generator in AS mode by making the necessary adaptations for AS mode, to couple the generator to the grid and generate power,

--: detectar las condiciones de entrada al modo seleccionado entre DFIG y FC, y activación del modo seleccionado cuando se cumplan las mismas. Detect the input conditions to the mode selected between DFIG and FC, and activate the selected mode when they are met.

6. Method for operating a wind turbine according to claim 1, characterized in that it comprises controlling the rotational resistance by short-circuiting the generator rotor.

7. Method for operating a wind turbine according to claim 1, characterized in that it comprises, -selecting the power converters intended for the control of the generator, and -selecting the power converters, or their components; who are not responsible for the control of the general

dor, and which are intended for the generation of reactive power that is injected directly into the network.

8. 8.: Método para operar un aerogenerador, según reivindicación 2, caracterizado porque las condiciones de entrada y salida están seleccionadas entre: -falta de operatividad parcial del sistema. -falta de operatividad total de los convertidores de potencia del sistema, -especiﬁcación del operador de red eléctrica, -especiﬁcación del controlador general del parque eólico, -criterios de optimización de rendimiento, -reserva de potencia activa requerida por el controlador de la turbina eólica, Method for operating a wind turbine, according to claim 2, characterized in that the input and output conditions are selected from: - partial lack of operability of the system. - Total operating capacity of the system power converters, - Specification of the power grid operator, - Specification of the general wind farm controller, - Performance optimization criteria, - Active power reserve required by the wind turbine controller ,

- increased availability during maintenance work, -Any combination of the above.

9. 9.: Sistema para operar un aerogenerador, que incluye al menos un generador asíncrono de rotor bobinado con al menos un estátor eléctricamente independiente; al menos un convertidor de potencia con capacidad de controlar las corrientes del generador seleccionadas entre rotóricas, estatóricas y combinación de las mismas en amplitud, frecuencia y fase; caracterizado porque comprende: System for operating a wind turbine, which includes at least one asynchronous winding rotor generator with at least one electrically independent stator; at least one power converter with the ability to control the generator currents selected from rotary, static and combination thereof in amplitude, frequency and phase; characterized in that it comprises:

--: elementos de maniobra de conexión/desconexión de los convertidores de potencia del estátor del generador, del rotor del generador, y de la red, switching elements for switching on / off the power converters of the generator stator, the generator rotor, and the grid,

--: elementos de maniobra de conexión/desconexión del estátor del generador de la red, operating elements for connecting / disconnecting the generator generator stator,

--: elementos de maniobra para cortocircuitar el rotor del generador, constituidos por una pluralidad de elementos seleccionados entre elementos activos, elementos pasivos y combinación de los mismos. maneuvering elements to short-circuit the generator rotor, consisting of a plurality of elements selected from active elements, passive elements and combination thereof.

10. 10.: Sistema para operar un aerogenerador, según reivindicación 9, caracterizado porque los elementos activos y los elementos pasivos que constituyen los elementos de maniobra están constituidos por elementos seleccionados entre elementos dependientes de los convertidores de potencia e independientes de los convertidores de potencia. System for operating a wind turbine, according to claim 9, characterized in that the active elements and the passive elements constituting the maneuvering elements are constituted by elements selected from elements dependent on the power converters and independent from the power converters.

11. eleven.: Sistema. para operar un aerogenerador, según reivindicación 9, caracterizado porque los elementos pasivos están seleccionados entre resistencias, inductancias, capacidades, y combinación de ellos. System. to operate a wind turbine, according to claim 9, characterized in that the passive elements are selected from resistors, inductances, capacities, and combination thereof.

12. 12.: Sistema para operar un aerogenerador, según reivindicación 9, caracterizado porque los elementos activos están seleccionados entre diodos, transistores, tiristores, otros semiconductores controlables y combinación de ellos. System for operating a wind turbine according to claim 9, characterized in that the active elements are selected among diodes, transistors, thyristors, other controllable semiconductors and a combination of them.

SPANISH OFFICE OF THE PATENTS AND BRAND

Application no .: 200803132

SPAIN

Date of submission of the application: 03.11.2008

Priority Date:

REPORT ON THE STATE OF THE TECHNIQUE

51 Int. Cl.: See Additional Sheet

RELEVANT DOCUMENTS

Categoría Category: Documentos citados Reivindicaciones afectadas Documents cited Claims Affected

X X: US 2007063677 A1 (SCHAUDER) 22.03.2007, figuras 1,2; párrafos 6,18. 1 US 2007 063677 A1 (SCHAUDER) 22.03.2007, figures 1,2; paragraphs 6.18. one

Y Y: 2,4-12 2,4-12

A TO: 3 3

Y Y: US 6628101 B2 (DYMOND et al.) 30.09.2003, figuras 1,3; columna 2, líneas 33-38,62-67. 2,5-12 US 6628101 B2 (DYMOND et al.) 30.09.2003, figures 1.3; column 2, lines 33-38,62-67. 2.5-12

Y Y: US 2005200337 A (SCHEIBER et al.) 15.09.2006 4 US 2005200337 A (SCHEIBER et al.) 09.15.2006 4

A TO: WO 2008026973 A1 (ABB RESEARCH) 06.03.2008, todo el documento. 1-12 WO 2008026973 A1 (ABB RESEARCH) 06.03.2008, the whole document. 1-12

A TO: US 2006214428 A1 (ALTERNMARK) 28.06.2006, todo el documento. 1-12 US 2006214428 A1 (ALTERNMARK) 28.06.2006, the whole document. 1-12

Categoría de los documentos citados X: de particular relevancia Y: de particular relevancia combinado con otro/s de la misma categoría A: refleja el estado de la técnica O: referido a divulgación no escrita P: publicado entre la fecha de prioridad y la de presentación de la solicitud E: documento anterior, pero publicado después de la fecha de presentación de la solicitud Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

El presente informe ha sido realizado • para todas las reivindicaciones • para las reivindicaciones nº: This report has been prepared • for all claims • for claims no:

Fecha de realización del informe 26.01.2011 Date of realization of the report 26.01.2011: Examinador L. García Aparicio Página 1/6 Examiner L. García Aparicio Page 1/6

REPORT OF THE STATE OF THE TECHNIQUE

Application number: 200803132

CLASSIFICATION OBJECT OF THE APPLICATION F03D7 / 02 (01.01.2006)

H02J3 / 38 (01.01.2006) H02P3 / 22 (01.01.2006) Minimum documentation sought (classification system followed by classification symbols)

F03D, H02J, H02P

Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENTIONS, EPODOC

State of the Art Report Page 2/6

WRITTEN OPINION

Application number: 200803132

Date of Completion of Written Opinion: 01.21.2011

Statement

Novedad (Art. 6.1 LP 11/1986) Novelty (Art. 6.1 LP 11/1986): Reivindicaciones Reivindicaciones 1-15 SI NO Claims Claims 1-15 IF NOT

Actividad inventiva (Art. 8.1 LP11/1986) Inventive activity (Art. 8.1 LP11 / 1986): Reivindicaciones 3 Reivindicaciones 1,2,4-12 SI NO Claims 3 Claims 1,2,4-12 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).

Opinion Base.-

This opinion has been made on the basis of the patent application as published.

State of the Art Report Page 3/6

WRITTEN OPINION

Application number: 200803132

1. Documents considered.-

The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Documento Document: Número Publicación o Identificación Fecha Publicación Publication or Identification Number publication date

D01 D01: US 2007063677 A1 (SCHAUDER) 22.03.2007 US 2007 063677 A1 (SCHAUDER) 03/22/2007

D02 D02: US 6628101 B2 (DYMOND et al.) 30.09.2003 US 6628101 B2 (DYMOND et al.) 09.30.2003

D03 D03: US 2005200337 A (SCHEIBER et al.) 15.09.2006 US 2005200337 A (SCHEIBER et al.) 15.09.2006

D04 D04: WO 2008026973 A1 (ABB RESEARCH) 06.03.2008 WO 2008026973 A1 (ABB RESEARCH) 06.03.2008

D05 D05: US 2006214428 A1 (ALTERNMARK) 28.06.2006 US 2006214428 A1 (ALTERNMARK) 06.28.2006

2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement

Of all the documents recovered from the state of the art, D1 is considered to be the closest to the invention being analyzed. The claims of the application are then compared with D1.

First claim

Document D1 shows several methods for operating a wind turbine that includes at least one asynchronous winding rotor generator with at least one electrically independent stator, at least one power converter capable of controlling the selected generator currents between rhetorical, static and combination of the same in amplitude, frequency and phase. The systems included in D1 can operate the wind turbine in a mode selected from full converter (FC, fig. 2) and doubly powered (DFIG, fig. 1). Therefore, the first claim has the following differences with respect to D1: -D1 does not contemplate the asynchronous mode of operation explicitly, that is, collected as an embodiment and with its independent figure. However, the asynchronous operation method is well known in the state of the art, and D1 implicitly mentions it in paragraph 6. To support the claim that the asynchronous mode of operation is well known, just read some of the documents. cited in the search report, for example: EP 1557925 A2 (SCHREIBER / SEMIKRON), WO2008026973 (ABB Research), which both have a contactor to switch from full converter mode to asynchronous mode. -D1 does not contemplate "a set of maneuver elements". As the first claim is written, its scope is ambiguous, as essential characteristics would be lacking. For example, it is not indicated that when changing operation mode some power control elements are the same, and that what changes is the state of the maneuvering elements and the power flow. The wording of this claim seems simply to accumulate the various ways of operating a wind turbine: FC, DFIG, and AS. Therefore, document D1 would be within the scope that the claim is trying to protect, and for that reason, it would lack inventive activity, as set forth in Article 33.3 of the PCT Treaty.

Second claim

The wording of the third claim is also ambiguous. The output conditions of the mode are not indicated of current operation, nor the input conditions to at least one mode of operation other than the mode of current operation It also does not indicate how the operating mode is selected other than the current operating mode. Document D2 does indicate the criteria used to change the mode of operation: the frequency of the current in the rotor (col. 2, lines 62-67). For all the above, the third claim would lack inventive activity.

Third claim

Document D1 does not contemplate a step from the full converter (FC) mode of operation to the DFIG mode of operation with the steps contemplated in this third claim. That is, here it is indicated that the generator rotor is connected to at least one power converter that is not in lack of partial operability, to operate in DFIG mode. Although the clarity could be improved to explain everything better, it is implicitly made known that the converter or converters to which the rotor is connected, were operating before in "full converter" mode. This detail was not collected by D1, and it does not appear to be evident to an expert in the field that started from D1 on the date the application was submitted. For all the foregoing, this claim would present inventive activity. It is also noted that some of the steps of the method of the third claim are ambiguous and not clearly delimited. They would be the following: -detect at least one output condition of the full converter (FC) mode,

State of the Art Report Page 4/6

WRITTEN OPINION

Application number: 200803132

-detect the input conditions to doubly fed mode (DFIG), -operate the generator in doubly fed mode (DFIG) making adaptations for the doubly fed mode (DFIG) -detect the input conditions to full converter (FC) mode and activate it when they are met. As it has been commented previously, it is not indicated what are the conditions of exit, nor of entrance. I do not know It explains what the mentioned adaptations are, nor the conditions for entering FC mode.

Fourth claim

Document D1 does not contemplate a step from the operating mode FC to the AS mode. However, document D3 does include such a possibility, with certain differences: D3 does not disconnect the generator stator from the power converters to which it is connected or disconnect the power converters from the network. In D3 the passage from one mode of operation to another is done by opening or closing the switch that communicates the stator with the network (30). This switch is between the converter connections (24 and 26). This difference does not seem significant for an expert in the field that started from D1 and in view of D3. It does not seem that combining the teachings of D1 with those of D3 involves inventive activity. All these documents belong to a well-known, well-defined and related field of technique, such as wind turbines, namely, the power electronics of such generators. For all the above, this claim would lack inventive activity. As in other claims, here are also some steps of the method that are ambiguous little precise: -detect at least one output condition of Full Converter (FC) mode -detect the input conditions to asynchronous (AS) mode - operate the generator in asynchronous mode (AS) by making adaptations for asynchronous mode (AS), to couple the generator to the grid and generate power, -detect the input conditions to the mode selected between doubly fed (DFIG) and full converter (FC ), and activation of the selected mode when they are met.

Fifth claim

For all the aforementioned, and especially when commenting on the second claim, this claim would also lack inventive activity. Document D2 short-circuits the rotor without having to disconnect the stator. This difference is not significant, since the D2 system could be operated perfectly as indicated in this claim without ever making an inventive effort. That is, the D2 system entails greater difficulty than that of this claim. D2 covers the operating modes shown here, which does not happen in reverse. For all the above this claim would lack inventive activity.

Sixth claim

Document D2 controls the rotational resistance by short-circuiting the generator rotor. It also has this characteristic D1. This detail is typical of the DFIG mode of operation. Therefore, this claim would lack inventive activity.

Seventh claim

The seventh claim suffers from a lack of clarity, as it does not indicate how the claimed end is achieved. Therefore, this claim would lack inventive activity.

Eighth Claim

The conditions of entry and exit, are usual and known conditions and that a person skilled in the art could occur in a more or less obvious way, and that would occur in any of the conditions of entry or exit outlined, therefore It would lack inventive activity.

Ninth claim

Elements of maneuver of connection / disconnection of the power converters of the generator stator of the generator rotor and of the network, are known, in fact in many documents the power converters are shown associated to maneuver elements that of disconnection thereof of the stator, rotor and network. It is also known in the state of the art of the provision of maneuvering elements for connecting / disconnecting the stator from the network, as well as for short-circuiting the rotor. Therefore, this claim would lack inventive activity. This claim is ambiguous and without any specificity, since it is not mentioned, where and how said maneuvering elements are arranged, in order to achieve the above purposes, which would also result in the possibility of being able to exchange with the same configuration in a way FC operation to a DFIG mode, an FC operation mode to AS, and a DFIG operation mode to AS.

State of the Art Report Page 5/6

WRITTEN OPINION

Application number: 200803132

Therefore, the assessment of the claim given in the present wording makes it lacking inventive activity.

Claims 10, 11 and 12

These claims only include variations or constructive concretions of the maneuvering elements, which are well known in the state of the art, therefore this claim lacks inventive activity.   Of all the documents recovered from the state of the art, D1 is considered to be the closest to the invention that It's analized. The claims of the application are then compared with D1.

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