Methods and apparatus for supplying and/or absorbing reactive power

ES 2 340 236 B2

DESCRIPTION

Procedures and apparatus for supplying and / or absorbing reactive electrical energy.

Object of the invention

This invention relates generally to wind turbines and, more specifically, to methods and apparatus for supplying and / or absorbing reactive electrical energy with respect to wind turbines.

Background of the invention

Wind energy is sometimes used to generate electrical energy using a wind turbine, in which an electrical generator is driven by the rotation of a rotor that converts wind energy into rotating energy. However, sometimes there may be inadequate wind power to drive the rotor, such that the wind turbine does not generate electrical power.

Description of the invention

In one aspect, a wind turbine includes a rotor having a hub, at least one rotor blade coupled to the hub, and a rotor shaft coupled to said hub for rotation therewith. The wind turbine also includes an electric generator coupled to the rotor shaft, and a frequency converter on the generator side electrically coupled to the electric generator to convert the variable frequency AC received from the electric generator into DC. The generator side frequency converter is electrically coupled to an electrical load and is configured for at least one of the following two functions: supplying reactive electrical energy to the electrical load and absorbing reactive electrical energy from the electrical load. The wind turbine also includes a grid-side frequency converter electrically coupled to the generator-side frequency converter to convert DC received from the generator-side frequency converter into fixed-frequency AC. The grid-side frequency converter is electrically coupled to the electrical load and is configured to perform at least one of the following functions: supply of reactive electrical energy to the electrical load or absorption of reactive electrical energy from the electrical load.

In another aspect, a method is provided for supplying reactive electrical power with respect to a wind turbine having an electrical generator, a frequency converter on the generator side electrically coupled to the electrical generator, and a frequency converter on the generator side. Electrically coupled network between the generator side frequency converter and an electrical load. The procedure includes supplying reactive electrical power to the electrical load using simultaneously the frequency converter on the generator side and the frequency converter on the grid side.

In another aspect, a method is provided for supplying reactive electrical power with respect to a wind turbine having an electrical generator, a frequency converter on the generator side electrically coupled to the electrical generator, a frequency converter on the generator side. the mains electrically coupled between the frequency converter on the generator side and an electrical load. The procedure includes the absorption of reactive electrical energy from the electrical load using simultaneously the frequency converter on the generator side and the frequency converter on the grid side.

Brief description of the drawings

Figure 1 is a perspective view of an exemplary embodiment of an exemplary wind turbine.

Figure 2 is a schematic diagram of the wind turbine shown in Figures 1 and 2.

Figure 3 is a flow chart illustrating an exemplary embodiment of a method for supplying reactive electrical power with respect to a wind turbine, such as, but not limited to, the wind turbine shown in Figures 1 and 2.

Figure 4 is a flow chart illustrating another exemplary embodiment of a method for supplying reactive electrical power with respect to a wind turbine, such as, but not limited to, the wind turbine shown in Figures 1 and 2.

Detailed description of the invention

As used herein, the term "blade" is intended to be representative of any device that provides reactive force when in motion relative to a surrounding fluid. As used herein, the term "wind turbine" is intended to be representative of any device that generates rotational energy from wind energy and, more specifically, converts the kinetic energy of the wind into mechanical energy. As used herein, the term "wind generator" is intended to be representative of any wind turbine that generates electrical energy from rotating energy generated from wind energy and, more specifically, converts converted mechanical energy from kinetic energy. of the wind into electrical energy.

ES 2 340 236 B2

FIG. 1 is a perspective of an exemplary embodiment of an exemplary wind turbine 10. The wind turbine 10 described and illustrated herein is a wind generator for generating electrical power from wind power. The exemplary wind turbine 10 described and illustrated herein includes a horizontal axis configuration. However, in some embodiments, the wind turbine 10 may include, in addition to or alternatively to the horizontal axis configuration, a vertical axis configuration (not shown). Wind turbine 10 is coupled to an electrical load (not shown in Figure 1), such as, but not limited to, an electrical grid, an energy storage device, a hydrogen electrolyzer, and / or an electric motor. , to receive auxiliary electrical energy therefrom and / or to supply the electrical energy generated by the wind turbine 10 to it. Although only one wind turbine 10 is illustrated, in some embodiments a plurality of wind turbines 10 may be grouped together, sometimes collectively referred to as a "wind farm."

Wind turbine 10 includes a body 12, sometimes referred to as a "nacelle", and a rotor (generally designated 14) coupled to body 12 for rotation with respect to body 12 about an axis 16 of rotation. In the exemplary embodiment, the nacelle 12 is mounted on a tower 18. However, in some embodiments, in addition to or alternatively to the nacelle 12 mounted on a tower, the wind turbine 10 includes a nacelle 12 adjoining the ground and / or a water surface. The height of tower 18 can be any suitable height that allows wind turbine 10 to function as described herein. Rotor 14 includes a hub 20 and a plurality of blades 22 (sometimes referred to as "blades") that extend radially outward from hub 20 to convert wind energy into rotational energy. Although rotor 14 is described and illustrated herein with three blades 22, rotor 14 can have any number of blades 22. Each of the blades 22 can be of any length (as described herein). For example, in some embodiments one or more rotor blades 22 are approximately 0.5 meters in length, while in some embodiments one or more rotor blades 22 are approximately 50 meters in length. Other examples of blade lengths 22 include 10 meters or less, approximately 20 meters, approximately 37 meters, and approximately 40 meters. Other examples include rotor blades 22 between about 50 and about 100 meters in length.

Despite how rotor blades 22 are illustrated in Figure 1, rotor 14 may have blades 22 of any shape and may have blades 22 of any type and / or configuration, whether or not it is described and / or illustrated herein. said shape, type and / or configuration. An example of another type, shape, and / or configuration of rotor blades 22 is in a cased rotor (not shown) having a turbine (not shown) contained within a conduit (not shown). Another example of another type, shape, and / or configuration of rotor blades 22 is in a Darrieus wind turbine, sometimes referred to as an "egg beater" turbine. Yet another example of another type, shape and / or configuration of rotor blades 22 is in a Savonious wind turbine. Yet another example of yet another type, shape and / or configuration of rotor blades 22 is in a traditional water pumping windmill, such as, but not limited to, four blade rotors having wood frames and cloth sails. . Furthermore, the wind turbine 10, in some embodiments, may be a wind turbine in which the rotor 14 is generally oriented against the wind to capture wind energy, and / or it may be a wind turbine in which the rotor 14 is generally oriented. downwind to direct energy. Of course, in any embodiment, the rotor 14 may not be oriented exactly upwind or downwind, but oriented at any angle (which may be variable) relative to the direction of the wind to harness the energy from the wind.

Referring now to Figure 2, the wind turbine 10 includes an electrical generator 24 coupled to the rotor 14 to generate electrical energy from the rotating energy generated by the rotor 14. The generator 24 can be any suitable type of electrical generator, such as such as, but not limited to, a wound rotor induction generator, a permanent magnet generator, a synchronous generator, and / or a squirrel cage induction generator. Generator 24 includes a stator (not shown) and a rotor (not shown). Rotor 14 includes a rotor shaft 26 coupled to rotor hub 20 for rotation therewith. The generator 24 is coupled to the rotor shaft 26 in such a way that the rotation of the rotor shaft 26 drives the rotation of the generator rotor and, consequently, the operation of the generator 24. In the exemplary embodiment, the generator rotor has a rotor shaft 28 coupled thereto and coupled to the rotor shaft 26 such that the rotation of the rotor shaft 26 drives the rotation of the generator rotor. In another embodiment, the generator rotor is directly coupled to rotor shaft 26, sometimes referred to as a "direct drive wind turbine." In the exemplary embodiment, the generator rotor shaft 28 is coupled to the rotor shaft 26 through a gearbox 30, although in other embodiments the generator rotor shaft 28 is directly coupled to the rotor shaft 26. More specifically, in the exemplary embodiment, gearbox 30 has a low speed side 32 coupled to rotor shaft 26 and a high speed side 34 coupled to generator rotor shaft 28. The torque of the rotor 14 drives the generator rotor to thereby generate variable frequency AC electrical power from the rotation of the rotor 14.

In the exemplary embodiment, the wind turbine 10 includes a frequency converter 36 on the generator side and a frequency converter 38 on the grid side, sometimes referred to as a double conversion wind turbine generator. More specifically, the generator side frequency converter 36 is electrically coupled to the generator 24 and converts the variable frequency AC received from the generator 24 to DC. The grid-side frequency converter 38 is electrically coupled to the generator-side frequency converter 36 and converts the DC received from the generator-side frequency converter 36 to fixed-frequency AC. The grid-side frequency converter 38 is also electrically coupled to an electrical load 40, such as, but not limited to, a power grid, an energy storage device, a hydrogen electrolyzer, and / or an electric motor. . During conditions in which wind energy is sufficient to drive the rotation of the rotor 14 and thereby generate electrical energy from the operation of the generator 24, the frequency converter 38 on the side of the

ES 2 340 236 B2 grid supplies fixed frequency AC to the load 40. The grid-side frequency converter 38 may also absorb and / or supply reactive electrical energy from the load 40. Each of the frequency converters 36 of the The grid side of the generator and frequency converter 38 may be located anywhere within or far from the wind turbine 10. For example, in the exemplary embodiment, each of a generator-side frequency converter 36 and a grid-side frequency converter 38 is located within a base (not shown) of tower 18.

As discussed above, the grid-side frequency converter 38 is electrically coupled to the electrical load 40 to supply reactive electrical energy thereto and to absorb reactive electrical energy therefrom. Furthermore, the generator side frequency converter 36 is electrically coupled to the electrical load 40 to supply reactive electrical energy thereto and to absorb reactive electrical energy therefrom. As such, both the grid-side frequency converter 38 and the generator-side frequency converter 36 are configured to supply reactive electrical energy to electrical load 40 and to absorb reactive electrical energy from electrical load 40 when power wind power is below a predetermined threshold, or when it is desired to supplement the supply or absorption of reactive electrical energy by the grid-side frequency converter 38 during the operation of the generator 24 using the generator-side frequency converter 36. The default threshold can have any value. For example, the predetermined threshold of wind energy may be a threshold value when the wind energy is not sufficient to drive the rotation of the rotor 14 and, consequently, it is not sufficient to operate the electrical generator 24 and generate electrical energy. Consequently, both the grid-side frequency converter 38 and the generator-side frequency converter 36 can be used to supply reactive electrical energy to, and / or absorb reactive electrical energy from, the electrical load 40 when wind power it is insufficient to generate electrical energy using the electrical generator 24. For example, reactive electrical energy may be supplied to, and / or absorbed from, electrical load 40 to facilitate regulation of a voltage of electrical load 40. In other embodiments, the predetermined threshold may be selected as a value at which the wind energy is sufficient to drive the rotation of the rotor 14 and therefore to generate electrical energy using the generator 24, but to which it is desirable to supplement the energy. reactive electrical energy generated by the grid-side frequency converter 38 with the reactive electrical energy generated by the generator-side frequency converter 36.

The generator-side frequency converter 36 and the grid-side frequency converter 38 may be electrically coupled to the electrical load in any manner, shape, configuration, and / or arrangement, and / or using any structure, and / or means that allows them to function as described and / or illustrated herein. For example, in the exemplary embodiment, the generator-side frequency converter 36 and the grid-side frequency converter 38 are coupled to the electrical load 40 in parallel, as shown in FIG. 2. Furthermore, in the exemplary embodiment, a switch 42 is electrically coupled along the electrical connection between the generator 24 and the generator-side frequency converter, and a switch 46 is electrically coupled along the electrical connection between the generator side converter 36 and electrical load 40. The switch 42 may be open to electrically isolate the generator-side frequency converter 36, and consequently the grid-side frequency converter 38, from the generator 24. When the switch 42 is closed, electrical energy can flow between the generator 24 and the frequency converter 36 on the generator side. In some embodiments, a switch 44 is electrically coupled along the electrical connection between the utility-side frequency converter 38 and the electrical load 40. The switch 44 may be open to electrically isolate the grid-side frequency converter 38, and consequently the generator-side frequency converter 36, from the electrical load 40. When the switch 44 is closed, electrical energy can flow between the electrical load 40 and the grid-side converter 38. In other embodiments, switch 44 is not included. Switch 46 may be open to electrically isolate generator-side frequency converter 36 from electrical load 40. When switch 46 is closed (and switch 44, when included, is closed), electrical energy can flow between electrical load 40 and generator-side frequency converter 36. When the wind energy is below the predetermined threshold, the generator-side frequency converter 36 and the grid-side frequency converter 38 can be used to supply reactive electrical energy to, and / or absorb reactive electrical energy from, electrical load 40 by opening, or holding open, switch 42 and closing, or holding closed, switch 46 (and switch 44, when included). Switches 42 and 46 (and 44, when included), can be any suitable switch, such as, but not limited to, a power electronic device, a contactor, a switch, and / or a circuit breaker.

In some embodiments, the wind turbine 10 may include one or more control systems 48 coupled to one or more components of the wind turbine 10 to generally control the operation of the wind turbine 10 and / or all or some of the components thereof. whether such components are described and / or illustrated herein. In the exemplary embodiment, the control system (s) 48 is (are) mounted within the nacelle 12. However, additionally or alternatively, one or more of the control systems 48 may be remote from the nacelle 12 and / or other components of the wind turbine 10. The control system (s) 48 may be used for, but not limited to, general system monitoring and control including, for example, but not limited to, steering and speed regulation, vehicle brake application. yaw and high speed shaft, pump and yaw motor application, and / or fault monitoring. In some embodiments, distributed or centralized control architectures may be used, alternatively.

As shown in FIG. 2, in the exemplary embodiment, the control system (s) 48 includes a manifold 50 or other communication device for communicating information. One or more processors 52 are coupled to the

ES 2 340 236 B2 collector 50 for processing information. The control system (s) 48 may also include one or more random access memories (RAM) 54 and / or other storage device (s) 56. RAM (s) 54 and storage device (s) 56 are coupled to manifold 50 to store and transfer information and instructions to be executed by processor (s) 52. The RAM (s) 54 (and / or also the storage device (s) 56, if included) can also be used to store temporary variables or other intermediate information during the execution of instructions by the (s) processors) 52. The control system (s) 48 may also include one or two read-only memories (ROM) 58 and / or other static storage devices coupled to the manifold 50 to store and provide static (i.e., non-changing) information and Instructions to processor (s) 52. The input / output device (s) 60 may include any device known in the art to allow input of data to the control system (s) 48, such as, but not limited to, input of data relating to the load. 40 electrical, and / or to allow outputs, such as, but not limited to, yaw control outputs, pitch control outputs, and / or switch control outputs to control the operation of switches 42, 44 , and / or 46. Instructions can be supplied to memory from a storage device, such as, but not limited to, a magnetic disk, a read-only memory integrated circuit (ROM), CD-ROM, and / or DVD, by means of a remote connection that is either wired or wireless that allows access to one or more electronically accessible media, etc. In some embodiments, hardwired circuitry may be used instead of or in combination with software instructions. Thus, the execution of instruction sequences is not limited to any specific combination of hardware circuitry and software instructions, whether described and / or illustrated herein.

The control system (s) 48 may also include a sensor interface 62 that allows the control system (s) 48 to communicate with any sensor. Sensor interface 62 may be or may include, for example, one or more analog-to-digital converters that convert analog signals to digital signals that can be used by processor (s) 52. The control system (s) 48 may be coupled, such as, but not limited to, electrically and / or optically, to both the generator-side frequency converter 36 and the utility-side frequency converter 38 to controlling the operation thereof in the electrical supply, such as, but not limited to, reactive to the electrical load 40, and / or absorption of electrical energy, such as, but not limited to, reactive to the electrical load 40. In the exemplary embodiment, control system (s) 48 is (are) electrically coupled to converters 36 and 38 as well as switches 42 and 46 (and 44, when included) to control operation. thereof. In some embodiments, the control system (s) 48 is coupled, such as, but not limited to, electrically and / or optically to the electrical load 40 to receive information regarding the load 40, such as, but not limited to a, operational parameters and / or conditions of the load 40, and / or to control the operation of the load 40. For example, in some embodiments, the control system (s) 48 receives voltage information or other information relating to the load 40 to regulate a voltage of the load 40 used by the converters 36 and / or 38, said information being received of a direct connection between control system (s) 48 and load 40, as in the exemplary embodiment, and / or of a sensor (not shown) via sensor interface 62.

In addition to or alternatively to the control system (s) 48, other control system (s) (not shown) may be used to control the operation of the load 40 and / or to control the operation of converters 36 and / or 38 in supplying electrical energy, such as, but not limited to, reactive to electrical load 40, and / or absorbing electrical energy, such as, but not limited to, reactive, electrical load 40 . Said other control system (s) include, but are not limited to, one or more control systems associated with other wind turbines (not shown), one or more centralized control systems for a wind farm , and / or one or more control systems associated with the load 40.

Figure 3 is a flow chart illustrating an exemplary embodiment of a method 100 for supplying reactive electrical power relative to a wind turbine, such as, but not limited to, wind turbine 10 (shown in Figures 1 and 2 ). Although procedure 100 will be described and illustrated herein with respect to wind turbine 10, procedure 100 is applicable to any wind generator. The method 100 simultaneously includes the supply 102 of reactive electrical power to the electrical load 40 (shown in FIG. 2) using the generator-side frequency converter 36 (shown in FIG. 2) and the frequency converter 38 on the generator side. the grid (shown in figure 2) when wind power is below the predetermined threshold set out above with respect to figure 2, or when it is desired to supplement the supply of reactive electrical energy through the grid-side frequency converter 38 during operation of the generator 24 using reactive electrical energy from the generator-side frequency converter 36. In some embodiments, the control system (s) 48 (shown in Figure 2) and / or other control systems may be used, such as, but not limited to, one or more control systems associated with other turbines. wind farms (not shown), one or more centralized control systems for a wind farm, and / or one or more control systems associated with load 40 to facilitate supply 102 of reactive electrical power to load 40.

Although method 100 may supply reactive electrical energy 102 to load 40 in any manner, mode, configuration, and / or arrangement, and / or using any method, process, structure, and / or means, in the exemplary embodiment, method 100 includes electrical isolation of the frequency converter 36 from the generator side of the generator 24 (shown in FIG. 2) by opening or holding open the switch 42 (shown in FIG. 2). Switch 46 (shown in Figure 2), and switch 44 (shown in Figure 2) if included, are closed or held closed to supply reactive electrical power to load 40. In some embodiments, reactive electrical power supplied to electrical load 40 is used to facilitate regulation 104 of a voltage of electrical load 40.

ES 2 340 236 B2

Figure 4 is a flow chart illustrating another exemplary embodiment of a method 200 for supplying reactive electrical power with respect to a wind turbine, such as, but not limited to, wind turbine 10 (shown in Figures 1 and 2). Although procedure 200 will be described and illustrated with respect to wind turbine 10, procedure 200 is applicable to any wind generator. The method 200 simultaneously includes the absorption 202 of reactive electrical energy from the electrical load 40 (shown in FIG. 2) using the generator-side frequency converter 36 (shown in FIG. 2) and the frequency converter 38 on the generator side. the grid (shown in figure 2) when wind power is below the predetermined threshold set out above with respect to figure 2, or when it is desired to supplement the absorption of reactive electrical energy by the grid-side frequency converter 38 during the operation of the generator 24 using the generator-side frequency converter 36. In some embodiments, the control system (s) 48 (shown in Figure 2) and / or other control systems may be used, such as, but not limited to, one or more control systems associated with other turbines. wind farms (not shown), one or more centralized control systems for a wind farm, and / or one or more control systems associated with load 40 to facilitate absorption 202 of reactive electrical energy from load 40.

Although method 200 can absorb 202 reactive electrical energy from load 40 in any manner, mode, configuration, and / or arrangement, and / or using any method, process, structure, and / or means, in the exemplary embodiment, method 200 includes electrical isolation of the generator side frequency converter 36 from generator 24 (shown in Figure 2) by opening or holding open switch 42 (shown in Figure 2). Switch 46 (shown in Figure 2), and switch 44 (shown in Figure 2) when included, are closed or held closed to absorb reactive electrical energy from load 40. In some embodiments, electrical energy is used reactive absorbed from electrical load 40 to facilitate regulation 204 of a voltage of electrical load 40.

Herein, exemplary embodiments are described and / or illustrated in detail. The embodiments are not limited to the particular embodiments described herein, but rather, the components and steps of each embodiment can be used independently and separately from the other components and steps described herein. Each component, and each step, can also be used with other components and / or process steps.

By introducing elements / components described and / or illustrated herein, the articles "a", "an", "the", "said / said", and "at least one" are meant to indicate that there is one or more of the element (s) / component (s) / etc. The terms "comprising", "including" and "having" are indicative of inclusion and mean that there may be element (s) / component (s) / etc. additional elements in addition to the element (s) / component (s) / etc. related.

Although the invention has been described with respect to various concrete embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the claims.

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ES 2 340 236 B2

List of parts

<td> 10</td><td>Wind turbine</td>

<td> 12</td><td>Gondola</td>

<td> 14</td><td>rotor</td>

<td> 16</td><td>Axis of rotation</td>

<td> 18</td><td>Tower</td>

<td> 20</td><td>Rotor hub</td>

<td> 22</td><td>Pallas</td>

<td> 24</td><td>generator</td>

<td> 26</td><td>Rotor shaft</td>

<td> 28</td><td>Rotor shaft</td>

<td> 30</td><td>Gearbox</td>

<td> 32</td><td>Low speed side</td>

<td> 34</td><td>High speed side</td>

<td> 36</td><td>Generator side frequency converter</td>

<td> 38</td><td>Grid-side frequency converter</td>

<td> 40</td><td>Load</td>

<td> 42</td><td>Switch</td>

<td> 44</td><td>Switch</td>

<td> 46</td><td>Switch</td>

<td> 48</td><td>System (s)</td>

<td> 50</td><td>Manifold</td>

<td> 52</td><td>Processor (s)</td>

<td> 54</td><td>RAM (s)</td>

<td> 56</td><td>Devices)</td>

<td> 58</td><td>Memories (ROM)</td>

<td> 60</td><td>Devices)</td>

<td> 62</td><td>Sensor interface</td>

<td> 100</td><td>Process</td>

<td> 102</td><td>Supply</td>

<td> 104</td><td>Regulation</td>

<td> 200</td><td>Process</td>

<td> 202</td><td>Absorption</td>

<td> 204</td><td>Regulation</td>