Lightning-suppressed wind power generation equipment

Abstract

The objective is to easily apply existing lightning suppression devices to wind turbines. [Solution] The present invention, which solves the above-mentioned problem, is a lightning-suppressed wind power generation facility X comprising an upright support 11, a generator 12 mounted on the top of the support 11 via the support 11, a hub H mounted on a drive shaft 13 that rotates and drives the generator 12, a plurality of blades B radially arranged on the hub H around the drive shaft 13, a charged body E provided at the tips of these blades B, and a capacitor provided in the internal space of the hub H, wherein the capacitor has a first electrode body 42 grounded via a ground wire L, and a second electrode body 43 that surrounds almost the entire first electrode body 42 via an electrical insulating layer 44 or electrical insulator 45 and is connected to the charged body E.

Description

[Technical field]

[0001] The present invention relates to a lightning-suppressed wind power generation facility having a function of suppressing lightning strikes on the wind power generation facility and protecting the wind power generation facility from lightning damage. [Background technology]

[0002] Lightning is an electrical discharge that occurs in the atmosphere. There are various types of lightning discharge, including intracloud discharge, intercloud discharge, and cloud-to-ground discharge. Of these, it is cloud-to-ground discharge (hereafter referred to as lightning) that causes the most damage. Lightning (electrical discharge to the ground) usually occurs under cumulonimbus clouds (clouds commonly known as thunderclouds) when the amount of electric charge inside the cloud becomes so large that a strong electric field is formed that exceeds the electrical breakdown of the air between the cloud and the ground. The mechanism of lightning strikes will now be described in more detail below.

[0003] Positive and negative charges are generated and accumulated within clouds by the interaction of rising air currents and particles (e.g., hail, ice crystals, water droplets) passing through various atmospheric temperature zones. First, moist air near the ground surface is transported upward by rising air currents, and as the temperature of the air decreases with altitude, it eventually becomes saturated with water vapor. And at the -10 degree mark, hail becomes negatively charged and ice crystals become positively charged, with the lighter ice crystals being transported upward by the updraft and the heavier hail being transported downward, resulting in a distribution of positive and negative charges within the cloud. Meanwhile, on the ground, charges of the opposite polarity (positive charges) corresponding to the charge at the cloud base gather and accumulate due to electrostatic induction, causing the voltage between the cloud and the ground to increase. Eventually, the insulation by the atmosphere is broken down, forming an electrical connection, causing a discharge between the cloud and the ground.

[0004] In addition, lightning does not occur until the electric field near the ground is about 100 to 150 times greater than the clear-weather electric field (about +100 to 200 volts per meter). In the case of winter lightning, the electric field near the ground can be an order of magnitude greater, more than 1,000 times greater than the clear-weather electric field. When a strong electric field is formed near the ground, any protruding part of the ground will emit positive and negative ions called "corona discharge" toward the bottom of the thundercloud with the opposite charge in the sky. This is the phenomenon known as the "welcoming discharge" that occurs just before a lightning strikes.

[0005] In the conventional lightning protection concept, it was considered impossible to prevent lightning strikes, and so most methods involved receiving the lightning strike with a needle-type lightning rod (Franklin rod) and directing it to the ground. In other words, conventional lightning rods exacerbate the above-mentioned phenomenon of backscattering, thereby "actively" causing lightning to strike (attract) the lightning rod itself.

[0006] In response to this, the present inventors have proposed a lightning suppression device as disclosed in Patent Document 1 or Patent Document 2, in order to protect an object to be protected by minimizing the occurrence of lightning strikes.

[0007] This lightning suppression device has an external electrode body and an internal electrode body (or an upper electrode body and a lower electrode body) that are arranged with an electrical insulator between them, and is configured such that only the internal electrode body (lower electrode body) is grounded.

[0008] For example, when a thundercloud with negative charges distributed at its base approaches, the opposite charge (positive charges) is distributed on the surface of the earth, and the grounded internal electrode body (lower electrode body) also becomes positively charged. The external electrode body (upper electrode body) is arranged around (above) this internal electrode body (lower electrode body) via an insulator containing an air layer, so that the external electrode body and internal electrode body (upper electrode body and lower electrode body) function as a capacitor with the internal electrode body (lower electrode body) grounded.

[0009] This prevents the electric charges that generate lightning discharges from flowing from the surface of the ground to the surface of the external electrode body (upper electrode body) until discharge breakdown of the capacitor occurs, thereby suppressing the lightning discharges that cause lightning strikes. As a result, it has become possible to suppress lightning strikes in a protected area centered around the lightning suppression device. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 6128539 [Patent Document 2] Patent No. 5839331 [Patent Document 3] JP 2024-038953 A Summary of the Invention [Problem to be solved by the invention]

[0011] Incidentally, in recent years, wind power generation facilities have been gaining attention as a type of power generation device that utilizes renewable energy.

[0012] This wind power generation facility is configured such that a generator covered by a nacelle is installed on the top of a support column, and a plurality of blades are attached to this generator for rotating the generator. Furthermore, some of the larger blades have a length of more than 100 m.

[0013] In this way, the upper part of the wind power generation facility is located in a position close to the thundercloud, and the tips of the blades in particular are easily struck by lightning because they approach the closest position to the thundercloud as a result of rotation.

[0014] For this reason, the inventors have come to the conclusion that it would be effective to impart the above-mentioned lightning suppression function to the tips of the blades in order to suppress lightning strikes on wind power generation facilities. On the other hand, even if the tip of the blade is given the above-mentioned lightning suppression function, the effect obtained is merely to "suppress" lightning strikes, and there are cases in which lightning strikes may still occur. In this case, there is a risk that the blades or the wind power generation facility itself may be damaged by a transient so-called lightning surge.

[0015] Therefore, the inventors further proposed a lightning-suppression type wind power generation facility and a wind turbine for wind power generation, as shown in Patent Document 3, with the aim of providing a lightning suppression effect on the blades and suppressing damage to the blades, etc., even if lightning does strike.

[0016] This lightning-suppression wind power generation facility and wind turbine for wind power generation has a configuration in which cylindrical capacitors are arranged in a ring shape like a cartridge inside the hub of the wind turbine, and the negative charge of the capacitor is guided from the hub to the tip of the blade, thereby imparting a lightning suppression effect to the blade. Secondly, a spherical lightning suppression device is provided as a capacitor at the tip of the blade. Of the above configurations, in terms of the difficulty of applying this to an actual wind turbine, the configuration in which the capacitor is provided inside the hub is more realistic, and can be installed not only in newly constructed wind turbines, but also as an add-on to existing wind turbines used for wind power generation.

[0017] However, the above invention has problems in that most of the space in the hub is occupied by the cylindrical capacitor, and the configuration of the capacitor is specialized for the hub of the wind turbine, and has low compatibility with lightning suppression devices that can be installed on other structures, etc. In addition, while this invention can suppress lightning strikes on the blades, it cannot be expected to have a lightning strike suppression effect on the nacelle, and a separate lightning suppression device must be installed on the top of the nacelle, so it would be preferable if the configuration of this device could be made common to the above-mentioned capacitor.

[0018] In view of the above problems, an object of the present invention is to provide a lightning-suppressed wind power generation facility to which existing lightning suppression devices can be easily applied. [Means for solving the problem]

[0019] The present invention, which solves the above-mentioned problems, is a lightning-suppressed wind power generation facility comprising an upright support, a generator mounted on the top of the support via the support, a hub mounted on a drive shaft that rotates and drives the generator, a plurality of blades arranged radially on the hub around the drive shaft, charged bodies provided at the tips of the blades, and a capacitor provided in the internal space of the hub, wherein the capacitor has a first electrode body grounded via a ground wire, and a second electrode body that surrounds almost the entire first electrode body via an electrical insulating layer or electrical insulator and is connected to the charged body. With this configuration, existing lightning suppression devices can be easily applied to wind turbines.

[0020] Another aspect of the present invention that solves the above-mentioned problems is a lightning-suppressed wind power generation facility comprising an upright support, a generator mounted on the top of the support via the support, a hub attached to a drive shaft that rotates and drives the generator, a plurality of blades arranged radially on the hub around the drive shaft, charged bodies provided at the tips of the blades, and a capacitor provided in the internal space of the hub, wherein the capacitor has a first electrode body grounded via a ground wire, and a second electrode body that faces the first electrode body via an electrical insulator and is connected to the charged body. With this configuration, existing lightning suppression devices can be easily applied to wind turbines.

[0021] In a preferred embodiment of the present invention, the capacitor is provided for each of the blades. This configuration provides symmetry in the mechanism from the hub to the blade tips, making the construction and maintenance of the power generation facility easier.

[0022] In a preferred embodiment of the present invention, the device further includes a switching unit capable of switching between an operating state in which the charged body is electrically connected to the second electrode body and a resting state in which the charged body is grounded. With this configuration, safety during maintenance work can be ensured. Effect of the Invention

[0023] The present invention, which solves the above-mentioned problems, provides a lightning-suppressed wind power generation facility to which existing lightning suppression devices can be easily applied. [Brief description of the drawings]

[0024] [Figure 1] 1 is a schematic diagram showing a lightning-suppressed wind power generation facility according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a perspective view showing an upper portion of a wind turbine for wind power generation according to an embodiment of the present invention. [Diagram 3] FIG. 2 is an enlarged vertical cross-sectional view showing a blade according to an embodiment of the present invention. [Figure 4] FIG. 2 is an enlarged vertical cross-sectional view showing an electrical resistor according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a cross-sectional view showing a nacelle and a hub according to an embodiment of the present invention. [Figure 6] 1 is a cross-sectional view showing a configuration of a lightning suppression device as a capacitor according to an embodiment of the present invention. [Figure 7] 10A to 10C are explanatory diagrams showing modified examples of a nacelle and a hub and the configuration of a lightning suppression device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, a lightning-suppressed wind power generation facility X according to each embodiment of the present invention will be described with reference to the drawings. The description will be made in detail in the order of the configuration of the embodiment, the method of implementation, and other examples. It should be noted that the following embodiments are merely examples of the present invention, and the present invention is not limited to the following embodiments.

[0026] First Embodiment As shown in FIG. 1, a lightning-suppressed wind power generation facility X includes a wind turbine 1 for generating electricity, and a power transmission facility 3 for transmitting the electricity generated by the wind turbine 1 via a power transmission line 2.

[0027] As shown in Figures 1 to 3, a wind power generating wind turbine 1 has a pillar 11 erected on the ground G, a generator 12 mounted on the top of the pillar 11, a hub H mounted on a drive shaft 13 that rotates and drives the generator 12, a plurality of blades B arranged radially around the drive shaft 13 on the hub H, a charged body E mounted on the tip of the blade B, a lightning suppression device 4 (described later) that is provided in the internal space of the hub H and acts as a capacitor that supplies charge to the charged body E, and an electrical resistor R that converts a portion of the discharge energy of a lightning strike, with the blade B as a receptor, into thermal energy.

[0028] With the above configuration, the wind turbine 1 for wind power generation converts wind energy into rotational motion by the multiple blades B, and generates power by driving the generator 12 with this rotational motion.

[0029] The support 11 is provided with a ground wire L therein, and the ground wire L is a conductive member capable of electrically connecting the inside of the nacelle N to the ground G. As a result, when the ground G becomes charged, the electric charge is guided to the ground side of the lightning suppression device 4.

[0030] In addition, the wind turbine 1 for wind power generation has a transmission 14 and a rotating electrical contact 15. The transmission 14, the generator 12, and a part of the drive shaft 13 are housed in the nacelle N. The rotary electrical contact 15 is interposed between the nacelle N and the hub H, and is electrically connected to the ground wire L. The configurations of the nacelle N (the generator 12, the drive shaft 13, the transmission 14), the hub H, and the rotary electrical contacts 15 are similar to those of known wind turbines for wind power generation.

[0031] As shown in FIG. 3, the blade B has a hollow portion k formed therein over almost the entire length. In addition, blade B has a flange f1 at its base, and flange f1 is fastened to flange f2 provided on hub H by a number of fastening members t (bolts and nuts), thereby fixing blade B to hub H. The blades B are formed of fiber-reinforced plastic such as fiberglass, similar to known wind turbines for wind power generation.

[0032] The charged body E is electrically connected via an electric resistor R provided inside the blade B to one of the electrodes of a lightning suppression device 4 (described later). In addition, a charged body E is provided at the tip of the blade B via a blade-side insulator I.

[0033] As shown in FIG. 4, the electrical resistor R has an elongated, approximately cylindrical shape extending over approximately the entire length of the blade B, and in this embodiment includes a support tube R1 and a non-metallic heating element R2 enclosed inside the support tube R1.

[0034] The support tube R1 is composed of a support tube main body R11 having both ends open, and a cover portion R12 that closes each opening of the support tube main body R11. In this case, the support tube body R11 can be made of an insulator, and the cover portion R12 can be made of a conductor.

[0035] The non-metallic heating element R2 is filled in the support cylinder R1, and can be made of ceramics containing, as a main component, a material selected from the group including, for example, SiC, MoSiO2, and ZrO2.

[0036] Furthermore, the non-metallic heating element R2 may be in the form of a powder, a sintered body, or a porous body, and there are no limitations on the materials and their ratios. In addition, the material of the non-metallic heating element R2 may also be a graphite electrode made of ceramics whose main component is graphite, or it may be a flexible conductive structure such as a conductive gel, conductive rubber, or conductive elastomer.

[0037] Here, the electric resistor R has male threads m formed on both ends thereof, and the male threads m and fixing means T fix and support the electric resistor R in the hollow portion k.

[0038] More specifically, as shown in FIG. 3, the fixing means T is formed by a first plate T1 provided in the hollow portion k and abutting against the base end of the charged body E, a second plate T2 hooked onto the base end of the blade B, and a plurality of nuts T3 screwed into each male thread portion m. The first plate T1 and the second plate T2 can be configured as insulators, with an electric resistor R passing through each of them.

[0039] The male screw portion m on the charged body E side is screwed into a screw hole h formed in the charged body E and communicating with the hollow portion k. In addition, the nut T3 on the charged body E side is screwed onto the male thread portion m in such a manner that the nut T3 and the charged body E sandwich the first plate T1, thereby connecting the charged body E and the electrical resistor R. Furthermore, a metal plate j, through which an electric resistor R is provided and passes, is clamped and fixed between the nut T3 on the hub H side and the second plate T2, and an electric wire W is attached to the metal plate j.

[0040] As shown in FIG. 5(a), a mounting shaft A extending from the base of the drive shaft 13 or the rotary electrical contact 15 is provided inside the hub H. Furthermore, as shown in FIG. 5(b), a plurality of lightning suppression devices 4 are provided radially from the mounting shaft A in the same direction as the blades B. In this case, it is preferable that one lightning suppression device 4 is provided for each blade B in accordance with the direction in which the blades B are provided. With this configuration, the space occupied inside the hub H can be minimized, and since the configuration from the blades B to the hub H is rotationally symmetrical, it is possible to efficiently install and remove the lightning suppression devices 4 and perform maintenance work on the entire inside of the hub H.

[0041] The mounting shaft A is a conductive shaft member that electrically connects the ground side of the lightning suppression device 4 and the rotary electrical contact 15, and is supported by a shaft support D inside the hub H.

[0042] The shaft support D is preferably composed of a support part D1 that extends inward from the outer wall of the hub H to support the mounting shaft A, and an insulating part D2 that insulates and holds the mounting shaft A. With this configuration, the electrical connection path from the mounting shaft A to the ground wire L is limited to the path via the rotary electrical contact 15, so that the electrically charged parts are limited and safety within the hub can be maintained.

[0043] 6 shows the configuration of the lightning suppression device 4 and the mounting axis A. The lightning suppression device 4 has a connecting pole 41 fixed in a direction intersecting the mounting axis A and electrically connected thereto, a first electrode body 42 provided at the tip of the connecting pole 41, and a second electrode body 43 surrounding almost the entire first electrode body 42 via an electrical insulating layer 44 and / or an electrical insulator 45. The lightning suppression device 4 further has an insulating covering portion 46 that covers a portion between the second electrode body 43 and the mounting axis A and a portion around the connection portion between the connecting pole 41 and the mounting axis A.

[0044] With this configuration, the first electrode body 42 is electrically connected to the ground G, and under lightning conditions, as described above, a positive charge is induced from the ground G through the ground wire L, the rotating electrical contact 15, the mounting shaft A, and the connection post 41. In contrast, the second electrode body 43 is negatively charged.

[0045] The second electrode body 43 is electrically connected to the charged body E via an electric wire W, and when the second electrode body 43 becomes negatively charged, a negative charge is induced in the charged body E, and a capacitor is formed from the blade B to the inside of the hub H via the lightning suppression device 4, thereby exerting a lightning suppression effect.

[0046] In this embodiment, as shown in Fig. 6, a configuration in which a switch S is provided between the second electrode body 43 and the charged body E is preferable. The switch S is a switching unit capable of switching an electrical connection path to one of two directions, and the base side of the switch S is connected to the blade side electric wire W1 connected to the charged body E, and the branch side of the switch S is connected to the electrode side electric wire W2 connected to the second electrode body 43 and the ground side electric wire W3 connected to the mounting shaft A (or any member electrically connected to the ground wire L).

[0047] By switching the switch S, it is possible to switch between two states: a state in which the blade side electric wire W1 and the electrode side electric wire W2 are connected, and a state in which the blade side electric wire W1 and the ground side electric wire W3 are connected. The former is an operating state in which the second electrode body 43 and the charged body E are electrically connected, and the latter is a resting state in which the charged body E is grounded (electrically connected to the ground G via the mounting shaft A, the ground wire L, etc.). This makes it possible to reduce the number of charged members when workers enter the wind turbine 1 (particularly the inside of the hub H) to perform maintenance work, etc., and makes it easier to ensure the safety of the workers.

[0048] The present invention may have the following configurations. However, the following configurations are merely examples, and the presence or absence of the configurations can be arbitrarily determined unless otherwise specified.

[0049] <Example of change> As shown in Figures 7(a) and 7(b), the lightning suppression device 4 provided inside the hub H may have a configuration including a first electrode body 42 that is grounded via a configuration similar to that up to the ground wire L including the aforementioned connecting pillar 41, and a second electrode body 43 that faces the first electrode body 42 via an electrical insulator 45 and is connected to a charged body E via an electric wire W.

[0050] In the above modified example, the first electrode body 42 and the second electrode body 43 are either bowl-shaped, hemispherical shell-shaped, or flattened hemispherical shell-shaped, and face each other with the electrical insulator 45 sandwiched between their open annular edge portions. The electrical insulator 45 is cylindrical or annular (cylindrical). With this configuration, the structure is simpler than the aforementioned spherical shell-shaped lightning suppression device 4, and the lightning suppression device 4 can be easily attached inside the hub H with a small number of parts.

[0051] The configurations shown above, including the modified examples, are merely examples in terms of the shapes and dimensions of the components, and can be modified in various ways based on design requirements, etc. [Explanation of symbols]

[0052] X Lightning-suppressed wind power generation equipment 1. Wind turbines for wind power generation 2. Power Lines 3. Power transmission facilities 4. Lightning Suppression Device 41 Connecting pillar 42 First electrode body 43 Second electrode body 44 Electrical insulation layer 45 Electrical Insulators 46 Covering part A Mounting shaft B-Blade D axis support D1 Support part D2 Insulation part E Charged body F flange G ground H Hub I Blade side insulator L Ground wire N Nacelle R Electrical resistor R1 support tube R2 Non-metallic heating element S Switch W electric wire W1 Blade side wire W2 Electrode side wire W3 Ground side wire

Claims

1. the generator is provided with a support pillar that is erected, a generator that is provided on the upper part of the support pillar through the support pillar, a hub that is provided on a drive shaft that drives and rotates the generator, a plurality of blades that are provided on the hub in a radial pattern centered on the drive shaft, charged bodies that are provided on the tips of the blades, a mounting shaft that is provided coaxially with the drive shaft, and a capacitor that is provided in the internal space of the hub, The capacitor is a lightning-suppressed wind power generation facility having a connecting pole capable of being connected to the mounting shaft at one end, a first electrode body connected to the other end of the connecting pole and grounded via the connecting pole and a ground wire, and a second electrode body that surrounds almost the entire first electrode body via an electrical insulating layer or electrical insulator and is connected to the charged body.

2. the generator is provided with a support pillar that is erected, a generator that is provided on the upper part of the support pillar through the support pillar, a hub that is provided on a drive shaft that drives and rotates the generator, a plurality of blades that are provided on the hub in a radial pattern centered on the drive shaft, charged bodies that are provided on the tips of the blades, a mounting shaft that is provided coaxially with the drive shaft, and a capacitor that is provided in the internal space of the hub, The capacitor is a lightning-suppressed wind power generation facility having a connection pole capable of being connected to the mounting shaft at one end, a first electrode body connected to the other end of the connection pole and grounded via the connection pole and a ground wire, and a second electrode body facing the first electrode body via an electrical insulator and connected to the charged body.

3. The capacitor is provided for each of the blades.

3. The lightning-suppressed wind power generation facility according to claim 1 or 2.

4. The charging device further includes a switching unit capable of switching between an operating state in which the charged body is electrically connected to the second electrode body and a resting state in which the charged body is grounded.

3. The lightning-suppressed wind power generation facility according to claim 1 or 2.

Images