OA19568A - Wind generator. - Google Patents

Abstract

The invention relates to a wind turbine 1 comprising: - a fixed structure 2, - a wind turbine 3 comprising a propeller 31 provided with at least two blades 311 and an axis 32 extending integrally from a hub 312 of the propeller and mounted freely rotatable on the fixed structure, to convert wind energy into mechanical energy, and - an electrical generator 4 comprising a rotor 41 integral with the wind turbine and a stator 42 integral with the fixed structure to convert the mechanical energy generated by the wind turbine into electrical energy. The rotor is fixed to the propeller so as to be distant from the axis of the wind turbine. The rotor is thus arranged so that its speed increases as the distance at which the rotor is fixed to the blades increases, for the same rotational speed of the wind turbine. A technical effect comparable to that of a multiplier is obtained, without however having the drawbacks thereof. <img file="OA19568A_A0001.tif"/> Fig. 3A

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to the field of devices for converting wind energy into electrical energy, such as a wind turbine coupled to an electric generator. A wind turbine is a device that converts the kinetic energy of the wind into mechanical energy, most often using a propeller with wings or blades extending from a hub of the propeller. An electrical generator here is a device that converts the mechanical energy generated by the wind turbine into electrical energy. The assembly comprising a wind turbine coupled with an electric generator to produce electricity from the energy of the wind is called a wind generator. This type of device makes it possible to produce electricity from a renewable energy source (kinetic energy of the wind), without greenhouse gas emissions. The wind generator according to the invention is advantageously suitable for any type of wind turbine, whether it is in particular with a vertical axis or a horizontal axis.

STATE OF THE ART

A wind turbine usually has a propeller mounted free to rotate on a fixed mast. The propeller has an axis of rotation from which the blades extend. The axis of rotation can advantageously be vertical. This allows, when the wind turbine is in a tower for sale to reduce to improve the output. This improvement in efficiency is achieved in particular with balancing to reduce contact friction and by specifically directing the wind on the wind turbine. The blades are arranged to drive the axis in rotation under the action of the wind. The axis is arranged in conjunction with an electrical generator to convert mechanical energy associated with the rotation of the axis into electrical energy.

In order to optimize the production of electrical energy, several types of electric generators have been developed, among which one of the most used is an asynchronous machine, also known under the term of induction machine, called 'squirrel cage. '.

In this type of electric generator, the propeller axis carries a rotor placed in the center of a stator fixedly mounted on the mast of the wind turbine. The rotor is provided with copper and aluminum bars and the stator comprises coils (or 'chokes' according to the English terminology) near which the bars of the rotor pass successively when the rotor turns, so as to disturb by induction the electromagnetic field generated by each coil when it is traversed by an electric current. The ends of each stator coil can be connected to phases of an electrical network to inject the electrical energy produced by the generator.

In a wind generator, this type of generator requires the use of a multiplier, for example geared, intended to transform the low speed of rotation of the axis of the wind turbine into a higher speed of rotation of the rotor. Indeed, if the rotor were directly connected to the wind turbine, the speed of rotation of the latter would be equal to that of the axis and would therefore often be insufficient to produce significant electrical energy. The multiplier therefore makes it possible to resolve the incompatibility between the number of revolutions / min of the blades of the wind turbine, which is generally low and the number of revolutions / min of the generator rotor, which must be high to produce electrical power (expressed in Watts ) significant.

However, the need to use a multiplier causes some limitations. In particular, it is subject to wear, it induces energy dissipation by friction which results in significant losses in efficiency, it has a high production cost and it requires maintenance at a non-negligible cost, which limits the overall efficiency of the wind generator.

To increase the overall efficiency of the wind generator with multiplier, one solution is to increase the number of stator coils. However, this solution also increases the starting torque of the generator. This drawback is also presented by solutions based on the arrangement of permanent magnets on the periphery of the rotor. Such a wind generator is for example known from the patent document referenced DE20203119U1. This latter type of wind generator also has drawbacks linked to the lack of variability in the magnetic field generated by a permanent magnet, the impossibility of disengaging the permanent magnet and the impossibility of adapting the magnetic field generated by the permanent magnet. the permanent magnet to a change of speed of rotation of the blades of the propeller.

There is therefore a need to provide a wind generator making it possible to overcome one or more of the aforementioned drawbacks. There is in particular a need to provide a wind turbine having improved efficiency. Another object of the invention is to provide a wind generator which does not require the use of a multiplier and exhibits good energy efficiency, while being robust and inexpensive.

SUMMARY OF THE INVENTION

To achieve this objective, a first aspect of the present invention relates to a wind turbine comprising:

- a fixed structure,

- a wind turbine comprising a propeller with at least two blades and an axis extending from a hub of the propeller and mounted freely in rotation on the fixed structure, to convert wind energy into mechanical energy, and

- an electrical generator comprising a rotor integral with the wind turbine and a stator integral with the fixed structure to convert the mechanical energy generated by the wind turbine into electrical energy.

The rotor of the electric generator can be fixed on the propeller, more particularly on at least one blade of the propeller and preferably at the end of at least one blade of the propeller, so as to be at a distance from the propeller. axis of the wind turbine.

The rotor can more particularly comprise at least one element based on a conductive material. Furthermore, the stator can include at least one coil fixed to the fixed structure. In this way, each element can pass close to each coil with each rotation of a complete revolution of the wind turbine around its axis.

Preferably, said at least one coil comprises at least one pair of coils, each pair of coils comprising:

- a primary coil intended to be connected to a source of electrical energy so that the primary coil generates a magnetic field when it is traversed by an electrical current supplied by the source of electrical energy, and

- a secondary coil intended to be connected to an electrical energy distribution network so as to inject into said network an electric current coming from the secondary coil and generated by disturbances of the magnetic field generated by the primary coil due to the passage of the elements made from conductive material when the rotor rotates.

The rotor is thus arranged at a distance from the axis of the wind turbine, so that the rotational speed of the rotor increases as this distance increases, for the same rotational speed of the wind turbine. A technical effect comparable to that sought by using a multiplier is thus obtained, without however having the drawbacks associated with the use of a multiplier. The wind generator is thus simple and easy to use. Its cost price is low compared to the cost of an existing wind turbine / multiplier assembly. The wind generator thus has a great capacity of adaptation according to the wingspan of the propeller blades.

In addition, the wind generator as introduced above is functional including, and preferably, when said at least one element based on a conductive material is not a permanent magnet. In this case, the wind generator advantageously avoids and solves the drawbacks associated with the use of one or more permanent magnets. These disadvantages include the creation of an electromagnetic starting torque and the lack of variability in the magnetic field. In addition, the inability to disengage the permanent magnet does not allow the magnetic field to adapt to a change in the speed of rotation of the propeller blades.

Preferably, the rotor is attached to the end of at least one blade.

A second aspect of the present invention relates to a kit comprising:

- a wind turbine comprising a propeller provided with at least two blades and an axis intended to extend from a hub of the propeller, and

- an electric generator comprising a rotor intended to be secured to the wind turbine and a stator to convert mechanical energy generated by the wind turbine into electrical energy, the stator and the wind turbine being clean and intended to be secured to a fixed structure, the axis of the wind turbine being rotatably mounted on the fixed structure to convert wind energy into mechanical energy,

The rotor of the electric generator is intended to be fixed on the propeller so as to be at a distance from the axis of the wind turbine, and is more particularly fixed to at least one blade of the propeller, to constitute a wind generator such as 'introduced above when the kit is assembled.

Preferably, the rotor comprises at least one element based on a conductive material and the stator comprises at least one coil fixed to the fixed structure, so that each element passes near each coil on each rotation of a complete revolution of the wind turbine around its axis, said at least one coil comprising at least one pair of coils, each pair of coils comprising:

a primary coil intended to be connected to an electrical energy source, and a secondary coil intended to be connected to an electrical energy distribution network.

A third aspect of the present invention relates to a wind tower comprising a wind turbine as introduced above.

BRIEF DESCRIPTION OF THE FIGURES

The aims, objects, as well as the characteristics and advantages of the invention will become more apparent from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which:

- Figure 1B illustrates a front view of the wind generator according to a first embodiment of the invention;

- Figure 1A is a sectional view along plane A-A of the wind generator illustrated in Figure 1B;

- Figure 1C is an enlargement of part B of Figure 1B on which magnetic field lines have been shown;

- Figure 2 illustrates a block diagram of an electronic control unit of the wind generator according to the first aspect of the invention;

- Figure 3A illustrates a front view of the wind generator according to a second embodiment of the invention;

- Figure 3B illustrates a front view of the wind generator according to a third embodiment of the invention;

- Figure 4 illustrates a partial sectional view of a wind tower according to the third aspect of the invention in which is shown a partial profile view of the wind generator according to the first aspect of the invention; and

- Figure 5 is a perspective view of the wind generator illustrated in Figure 3A.

The accompanying drawings are given by way of example and are not limiting of the invention. These drawings are schematic representations and are not necessarily to the scale of practical application.

DETAILED DESCRIPTION OF THE INVENTION

Before starting a detailed review of embodiments of the invention, optional features are listed below which can optionally be used in combination or alternatively:

- said at least one element may extend substantially parallel to the axis of the wind turbine. This arrangement of the elements makes it possible to prevent the breaking of the magnetic field, or even the percussion of the elements on the stator, due to the variation of the deflection of the blades in strong winds;

- the conductive material on the basis of which at least one element is made can comprise a mild steel, preferably with a low carbon content,

- Each element can have a plate shape having dimensions of 10 to 50 mm, preferably equal to 30 mm, in length, from 5 to 20 mm, preferably equal to 10 mm, in width, and from 0.1 to 2 mm, preferably equal to 0.5 mm, in thickness;

- the rotor may further comprise an annular support fixed to at least one blade of the propeller concentrically with the hub of the propeller, said at least one element being fixed to the annular support. The wind generator can thus include a number of elements greater than the number of blades of the propeller insofar as the elements are anchored to the annular support. This makes it possible firstly to compensate for a slow rotation of the propeller which would be due to a weak wind, and thus to optimize the performance of the wind generator in this case, and secondly to mechanically consolidate the blades between them when the annular support is fixed. to each of the blades. More particularly, the propeller may have a wingspan of between 40 and 100 cm, preferably equal to 60 cm, and supports between 10 and 80, preferably between 40 and 50, elements, the elements being for example distributed at regular intervals over the annular support;

-the stator may comprise a set of three pairs of coils identical to each other which are for example distributed in rotational symmetry with respect to the axis of the wind turbine. Each secondary coil is intended to be connected to the electrical energy distribution network via an electrical contactor configured to open when the wind turbine rotates at a speed greater than a first threshold value. Each secondary coil can thus be disconnected to neutralize the magnetic field by electric disengagement in a situation of strong limit or extreme winds causing the wind turbine to rotate at a speed liable to damage the wind generator. Each primary coil can also be intended to be connected to the source of electrical energy via an electrical contactor configured to open when the wind turbine rotates at a speed greater than a second threshold value. Each primary coil can thus be disconnected when the speed of rotation of the wind turbine is greater than a second threshold value defined as sufficient for the production of significant electrical energy by the secondary coils;

- the wind generator can comprise at least two, preferably three, or more than three, sets of pairs of coils, each set comprising at least one pair, preferably three pairs, or more than three pairs, of coils, and each coil secondary of a pair of coils of an assembly having a surface and a section different from those of each secondary coil of each pair of coils of each of the other assemblies. The wind generator can further comprise an electronic regulator configured to successively engage and disengage all or part of each set of pairs of coils as a function of a parameter relating to the wind energy to be converted, for example as a function of the speed of rotation. of the wind turbine. Such sets of increasing sizing allow the wind generator according to the first aspect of the invention to broaden and optimize the power generation field from weak to very weak winds up to strong to very strong winds;

- the fixed structure may include a fairing of the propeller which may take the form of a diffuser, the stator being optionally attached to the fairing. Compared to non-ducted propellers, such a ducted propeller makes it possible, in addition to constituting a safety element, to increase the efficiency of the wind generator, in particular when the fairing takes the form of a diffuser;

- the wind generator can include at least one stay, each stay being configured between the axis of the wind turbine and a blade of the propeller to keep it in a position substantially perpendicular to the axis of the wind turbine. The variation of the blade deflection in light to strong winds can thus be neutralized;

- the wind generator can include three pairs of primary and secondary coils configured so that the wind generator produces the three phases of a three-phase current; and

- the axis of rotation of the wind turbine can be vertical.

The present invention finds for its preferred field of application small and medium-sized wind towers, in particular those for domestic use. However, the present invention is also suitable for being implemented in large wind towers, such as an offshore wind turbine.

Referring to Figures 1A to 1C, a first aspect of the invention relates to a wind turbine 1 particularly intended to equip a wind tower. The wind generator 1 comprises a fixed structure 2, a wind turbine 3 for converting wind energy into mechanical energy and an electrical generator 4 for converting the mechanical energy generated by the wind turbine 3 into electrical energy.

The wind turbine 3 comprises a propeller 31, provided with at least two blades 311, preferably with three blades 311, and an axis 32. The number of blades 311, at least two, will depend on the wind conditions and performance. desired on a given site. The axis 32 is integral with the propeller 31 and extends through a first end from a hub 312 thereof. By a second end, the axis 32 is mounted to rotate freely on the fixed structure 2.

The electric generator 4 comprises a rotor 41 integral with the wind turbine 3 and a stator 42 integral with the fixed structure 2. Optionally, the axis 32 of the wind turbine 3 and the stator 42 are not integral with the same part of the fixed structure 2, but are integral with different parts, but integral with each other, of the fixed structure 2.

As particularly illustrated in Figure 1C, the rotor 41 of the electric generator 4 is attached at least in part to at least one blade 311 of the propeller 31. This attachment can be direct or indirect; in the second case it involves an intermediate fixing element between the rotor 41 and the propeller 31.

More particularly, the rotor 41 comprises at least one element 411 based on a conductive material fixed to at least one blade 311 of the propeller 31. Preferably, each blade 311 of the propeller 31 supports at least one element 411 of the propeller. rotor, each element preferably being spaced from the hub 312 of the propeller by the same distance, so that the elements 411 are distributed in a circle concentric with the hub 312 of the propeller 31 and therefore with the axis 32 of the wind turbine 3.

The conductive material on the basis of which at least one element 411 is made comprises a mild steel, preferably with a low carbon content, for example of type A40. Alternatively, the elements 411 are made of copper, aluminum or other conductive metals. In addition, if desired, the elements 411 can be magnetized. At least some of them can be electrically connected to each other. This electrical connection is preferably made, but not necessarily, by a metal ring, for example made of aluminum, joining them together. This role of electrical connection can for example be played by the aforementioned annular support 412 and detailed below.

Each element 411 may have a plate shape having dimensions of 10 to 50 mm, preferably equal to 30 mm, in length, from 5 to 20 mm, preferably equal to 10 mm, in width, and from 0.1 to 2 mm, preferably equal to 0.5 mm, in thickness. These dimensions are given as an indicative and nonlimiting example. In addition, other shapes are conceivable such as a bar shape or a frustoconical shape or an ovoidal section shape. However, the shape of the elements 411 preferably has a longer dimension than its other dimensions.

According to a preferred embodiment, each element 411 is attached to the distal end of a blade 311 of the propeller 31. However, this preferred embodiment is not limiting; for example, each element 411 can be fixed midway between the hub 312 and the distal end of a blade 311 of the propeller 31; for another example, two elements 411 of the rotor 41 can be fixed to each blade at different distances from the hub 312 of the propeller 31. The wind generator 1 has a great capacity for adaptation, and in particular for continuous adaptation, depending on the span of the blades 311 of the propeller 31. The propeller 31 may have a wingspan of between 40 and 100 cm; it is preferably substantially equal to 60 cm. A propeller 31 of such a scale is particularly well suited to a wind tower for domestic use. However, the wind generator 1 according to the invention is by no means limited to an application in a wind tower; on the contrary, it is also suitable for horizontal axis wind turbines and wind turbines with a propeller with a wingspan of up to 5 m or more.

The rotor 41 is thus arranged at a distance from the axis 32 of the wind turbine 3. In this way, the speed of the rotor 41 increases as this distance increases, for the same speed of rotation of the wind turbine 3. We obtain thus a technical effect comparable to that sought by using a multiplier, without however presenting the drawbacks associated with the use of a multiplier. Indeed, the technical effect obtained is without giving rise to wear, since it no longer induces the gears of a multiplier. For this same reason, the technical effect obtained is without energy dissipation by friction and therefore without loss of efficiency. The technical effect obtained I is with a low cost price compared to the cost price of a multiplier. In addition, the technical effect obtained is without requiring maintenance as heavy as that required by the use of a multiplier. For these various reasons, the overall efficiency of the wind generator 1 according to the first aspect of the invention is already greatly improved compared to a wind generator implementing a standard multiplier. This improvement is all the more appreciable on small or medium-sized wind turbines.

The stator 42 for its part may comprise at least one coil 420a, 420b fixed to the fixed structure 2. Said at least one coil 420a, 420b is arranged on the fixed structure 2 so that each element 411 passes close to each coil 420a. , 420b on each rotation of a complete revolution of the wind turbine 3 around its axis 32. Each coil of the stator 42 can be produced by winding a wire of copper, aluminum or another conductive metal.

More particularly, according to the first embodiment of the wind generator 1 illustrated in FIGS. 1A to 1C, each coil 420a, 420b comprises an axis which is arranged radially with respect to the generally circular extent of the propeller 31. In this way , each element 411 passes near one end of each coil 420a, 420b on each rotation of a complete revolution of the wind turbine 3 around its axis 32.

More particularly, the stator 42 comprises at least one pair of coils including a primary coil 420a and a secondary coil 420b.

With reference to FIG. 2, the primary coil 420a of each pair is intended to be connected to a source of electrical energy 5. The secondary coil 420b of each pair is intended to be connected to a distribution network 6 of electrical energy. .

The role of each primary coil 420a is first and foremost to generate a magnetic field when an electric current passes through it which is supplied by the source of electrical energy 5. Said magnetic field is illustrated in Figure 1C in the form of field lines. Plates, for example made of iron, can be arranged as shown in FIGS. 1A to 1C at the center and along the axis of each primary coil 420a to act as a magnetic circuit making it possible to channel the magnetic field and to limit its effects. losses. The primary coils 420a can be electrically connected to one another by wire links as illustrated in FIG. 1B. It should be noted that, as an alternative, each primary coil 420a can be replaced by a permanent magnet, but this has several drawbacks, in particular as regards the creation of an electromagnetic starting torque, the absence of variability of the field magnetic generated by a permanent magnet, the impossibility of disengaging the permanent magnet and of adapting the magnetic field to a change in speed of rotation of the blades 311 of the propeller 31. In contrast, the use of a primary coil 420a offers corresponding advantages. It generates a variable primary magnetic field depending on the power supply it receives from the electrical power source. With reference to FIG. 2, the variability of the primary magnetic field can be obtained and controlled by a direction reversing regulator 10 and / or by a control electronics comprising for example a first electronic regulator 7 of the supply current of the primary coil. as a function of at least one of the acceleration, the speed and the deceleration of the propeller 31. These parameters can be measured by an ad hoc sensor 9 as illustrated in FIG. 2 arranged in relation to the rotor 41 and functionally connected, for example by wire connection, to the first electronic regulator 7. The wind generator 1 thus allows, with the aid of electronics, a self-regulation according to the variation of the speed of the wind expressed in number of revolutions of the wind turbine 3 per unit of time. If necessary, the primary magnetic field can be controlled so as to overcome the moment of inertia of propeller 31 and begin its rotation in light winds. Moreover, once the rotation of the propeller 31 is engaged, each primary coil 420a, or at least some of them, can be disconnected by a starting contactor for example included and controlled by the first electronic regulator 7. The possibility disengaging the primary coils 420a makes it possible to neutralize the magnetic field in a situation of strong limit or extreme winds, for safety reasons. Further, a first rectifier 11 may be provided to convert direct current from the electric power source 5 to alternating current.

The role of each secondary coil 420b is to generate an electric current due to the variation of the magnetic field induced by the successive passages of the elements 411 of the rotor 41 near the end of the primary coil 420a of the same pair when the propeller 31 turns. The secondary coils 420b can be electrically connected to each other by wire links as shown in the figure

1B.

The combination of the primary and secondary coils of each pair allows, with the help of electronics, to regulate and optimize the efficiency of the wind generator 1.

With reference to FIG. 2, the electric current generated by each secondary coil 420b is intended to be injected, optionally after treatment, into the electrical distribution network 6. Said treatment is for example carried out at least in part by a second regulator. current 8 as a function of at least one of the nature, intensity, voltage and power of the electric current generated by the secondary coils 420b. The processing of the electric current generated in the secondary coils 420b can also involve a second rectifier 12.

Each secondary coil 420b is intended to be connected to the distribution network (6) of electrical energy via an electrical contactor for example included and controlled by the second electronic regulator 8 and configured to open when I wind turbine 3 turns at a higher speed to a first predetermined threshold value, to enable the wind generator 1 to be disengaged in a situation of strong limit or extreme winds, for safety reasons.

According to the first embodiment illustrated in Figures 1A to 1C, the secondary coil 420b is arranged concentrically to the primary coil 420a. Coils 420a and 420b can be nested within each other, potentially having the same diameter, without contacting each other. They are electrically isolated from each other.

Note here that as illustrated in Figures 3A and 3B, the wind turbines 1 according to the second and third embodiments of the invention comprise pairs 420, 421,422, 430, 431,432, 440, 441,442 of which each coil is arranged tangentially to the circular extent of the propeller 31. According to the illustrated examples, the primary coils of these pairs of coils are arranged closer to the hub 312 of the propeller 31 than the secondary coils, but a reverse configuration is quite functional . Each primary coil 420a, 421a, 422a, 430a, 431a, 432a, 440a, 441a, 442a, as well as each secondary coil 420b, 421b, 422b, 430b, 431b, 432b, 440b, 441b, 442b, can also be arranged together with a magnetic circuit essentially centered with respect to the coil. The magnetic circuit of a primary coil is then also potentially curved so as to face, through its ends, the ends of the magnetic circuit of the corresponding secondary coil, so as to form a closed magnetic circuit, the magnetic circuits however remaining distant from one another. the other to allow the successive passages of the elements 411 of the rotor 41 between the primary and secondary coils of each pair 420, 421,422, 430, 431,432, 440, 441,442.

Each of the aforementioned magnetic circuits can be made from a conductive material such as mild steel, preferably low carbon, for example of type A40. Alternatively, they are made of copper, aluminum or another conductive metal.

Preferably, the stator 42 comprises a set of three pairs 420, 421, 422 of coils identical to each other which are for example distributed in rotational symmetry with respect to the axis 32 of the wind turbine 3. In this way, the The wind generator makes it possible to produce the three phases of a three-phase current, for example having a frequency of 50 or 60 Hz and an effective voltage of 230 or 380 V. If necessary, it is possible to convert this three-phase current into direct current, for example a voltage of 12 or 24 V, through the second rectifier 12.

The necessary importance of the diameter of the propeller 31, in search of torque, is exploited by the possibility of greatly increasing the number of coils 420a, 420b, 421a, 421b, 422a and 422b on the stator 42 without suffering the disadvantages of electromagnetic resistance torque of existing wind turbines. The possibility of increasing the number of coils makes it possible to reduce the speed of the propeller 31 while benefiting from a high circular speed of the elements 411 of the rotor 41 necessary for the production of electrical energy, this high circular speed being itself. even acquired by the importance of the diameter of the wind turbine. However, tests on a small wind turbine 3 made it possible to limit the number of primary / secondary coils to three. However, as described below, other sets of three coils can be added to capture stronger to much stronger winds.

Other particular characteristics of the wind generator 1 according to the first aspect of the invention are described below which make it possible to further increase the efficiency of the wind generator 1.

According to a first of these characteristics, in a manner adapted to each embodiment envisaged and as particularly illustrated in FIG. 4, each element 411 can extend substantially parallel to the axis 32 of the wind turbine 3, from the blades 311 of the propeller 31. This arrangement of the elements 411 makes it possible to prevent the breaking of the magnetic field, or even the percussion of the elements 411 on the stator 42, and more particularly against the coils 420a, 420b of the stator 42, due to the bending of the blades 311 of the propeller 31, or equivalent of the variation of the deflection of the blades 311 of the propeller 31, in strong winds.

As already mentioned above, in a manner adapted to each embodiment envisaged and as illustrated in particular in FIGS. 1A to 1C and in FIGS. 3A, 3B and 5, the rotor 41 may further comprise an annular support 412. The annular support 412 is preferably fixed to be on all sides at an equal distance from the axis 32 of the wind turbine 3, concentrically with the hub 312 of the propeller 31. For example, the annular support 412 is fixed on at least one blade 311 of the propeller 31, preferably on each blade 311 of the propeller 31. The elements 411 of the rotor 41 are fixed to the annular support 412. In this way, the propeller 31, having a wingspan of between 40 and 100 cm, can support between 10 and 80, preferably between 40 and 50, elements 411. These elements 411 are for example distributed at regular intervals on the annular support 412. The wind generator 1 can thus comprise a number of elements much greater than the number of elements. number of blades 311 of the propeller 31 insofar as the elements 411 are anchored on the annular support 412. This makes it possible firstly to compensate for a slow rotation of the propeller 31 which would be due to a weak wind, and thus to optimize the performance of the wind generator 1 in this case, and secondly to mechanically consolidate the blades 311 of the propeller 31 between them when the annular support 412 is fixed to each of the blades 311. In fact, in the case of weak winds and as a consequence of a slow rotation of the rotor 41, the observed circular speed at the end of the blades 311, the high number of elements 411 and, where appropriate, of coils 420a, 420b have the effect of compensating for the slow rotation of the rotor 41 and significantly increasing the performance compared to existing wind turbines. Furthermore, tests have shown that the larger the diameter of the propeller 31, and therefore of the rotor 41, the smaller the number of elements 411 required is because the circular speed of each element 411 is the same. increased.

O

The number of elements 411 required is therefore inversely proportional to the diameter of the propeller 31 and in particular of the rotor 41.

The increase in the number of elements is carried out in the wind generator 1 according to the first aspect of the invention without creating an electromagnetic torque resistance 5 on start-up, the latter also being able to be modulated and controlled by electronic management. The large diameter of the rotor 41 becomes an advantage, unlike existing wind turbines, especially in small to medium-sized wind turbines, which requires a multiplier, a source of yield loss and maintenance obligation. The blades 311 of the propeller 31 have a dual function "force / torque" and "rotor".

According to the third embodiment of the wind generator 1, and with reference to FIG. 3B, the wind generator 1 can comprise at least two, preferably three, sets of pairs 420, 421, 422, 430, 431, 432, 440 , 441, 442 of coils. Each set includes at least one pair, preferably three pairs, of coils.

Each secondary coil 420b, 421b, 422b; 430b, 431b, 432b; 440b, 441b, 442b of a pair of coils in one set may have a different area and section from that of each secondary coil of each pair of coils of each of the other sets. The first set 420, 421, 422 comprises, for example, coils which are undersized with respect to the coils of the other two sets 430, 431, 432 and 440, 441, 442; the first set is then especially suitable in the event of weak winds. The third assembly 440, 441, 442 comprises, for example, coils which are oversized with respect to the coils of the other two assemblies 420, 421, 422 and 430, 431, 432; the third assembly 440, 441, 442 is then especially suitable in the event of strong to very strong controlled winds (for example by mechanical safety systems with "valves" provided upstream of the propeller 31). The first set 420, 421, 422, or even the second set 430, 431, 432, may possibly not withstand such strong to very strong winds, even when controlled, without this causing damage due to overloading. However, the first set 420, 421, 422, or even the second set 430, 431, 432, is necessary to start producing electricity at weak to moderate winds and makes it possible to reduce the starting electromagnetic torque as much as possible. .

In addition, the first electronic regulator 7 can be configured to successively engage and disengage all or part of each set of pairs 420, 421, 422, 430, 431, 432, 440, 441, 442 of coils according to a parameter 35 relating to the wind energy to be converted, for example as a function of the speed of rotation of the wind turbine 3. The first electronic regulator 7 can therefore be suitable for managing the engagement and disengagement of all or part of each assembly as a function of different wind patterns. In addition, the supply of electrical energy to the primary coils of one set can be ensured, in a controlled manner by the first electronic regulator 7, by tapping the electrical energy generated at the level of the secondary coils of another set, rather than 'using the electric power source 5.

Such assemblies of increasing sizing allow the wind generator 1 according to the first aspect of the invention to widen and optimize the power generation field from weak to very weak winds up to strong to very strong winds, by securing at any time the coils of a possible overload and consequently avoiding degradation and maintenances. It should be noted that on the rotor 41, the elements 411 anchored on the circular support 412 fixed at the end of the blades 311 have universal use for each set of pairs of coils.

Referring to Figure 4, the fixed structure 2 may include a shroud 21 of the propeller 31. The shroud 21 may take the form of a diffuser. The stator 42 is if necessary fixed to the fairing 21 of the fixed structure 2. To be compared with non-ducted propellers, such a ducted propeller 31 makes it possible, in addition to constituting a safety element, to increase the efficiency of the wind generator 1. , in particular when the fairing 21 takes the form of a diffuser. The fixed structure 2 as illustrated in Figure 4 is that of a wind tower according to the third aspect of the invention. However, the fixed structure 2 is not limited to that of a wind tower; it can for example include a wind turbine mast, anchored to the ground or resting on a floating structure (for off-shore wind turbines). In this case, the fairing 21 can take the form of a substantially annular diffuser which does not extend, in particular in a substantially continuous manner, the fixed structure 2. In this sense also, the fairing 21 and the stator 42 can be fixed independently. from each other to the fixed structure 2.

Still with reference to FIG. 4, the wind generator 1 according to one or other of its embodiments may further comprise at least one stay 33, and preferably as many stay 33 as the propeller 31 has blades. 311. Each stay 33 is configured between the axis 32 of the wind turbine 3 and a blade 311 of the propeller 31 to maintain it in a position substantially perpendicular to the axis 32 of the wind turbine 3. Each stay 33 can more in particular be anchored between approximately the outer 2/3 of each blade 311 and the axis 32 of the wind turbine 3, forming an angle with the axis 32 of the wind turbine 3 of between 20 and 75 °. The shrouds 33 make it possible to stiffen and lighten the "wind turbine 3 / rotor 42" assembly and to prevent the "sag" phenomenon which could adversely affect the continuity of the magnetic field with the coils 420a, 420b of the stator 42.

The wind generator 1 according to the first aspect of the invention is thus simple and easy to implement. Its cost price is low compared to that of an existing wind turbine / multiplier assembly. The performance of this wind generator 1 makes it possible to envisage the installation of micro-power stations, either connected to the monopoly network, or in a central-autonomous concept (with batteries) to distribute electrical energy to a limited number of homes. In addition, this wind generator 1 can optionally be adapted to existing bladed wind turbines, either with a vertical axis or with a horizontal axis.

The source of electrical energy 5, the first electronic regulator 7, the second electronic regulator 8, the direction reversing regulator 10, the first rectifier 11 and the second rectifier 12 can be integrated in an electronic control cabinet supplied, if necessary, by the electric power source 5 itself.

The wind generator 1 according to the first aspect of the invention is suitable and intended to be integrated into a wide variety of wind tower 0, and in particular integrated into a wind tower 0 comprising, with reference to FIG. 4:

an air intake device comprising at least one nozzle 22 extending from a first end to a second end, each first end being configured to be able to capture an air flow coming from the environment outside the system ,

- a conversion device comprising at least:

o a chamber 23 in which said at least one nozzle 22 opens at its second end and o a wind generator 1 according to the first aspect of the invention, and

- an air evacuation device from the conversion device to the environment outside the wind tower 0.

This type of ducted wind tower makes it possible to exploit, for the inlet winds, but also the outlet winds, the Venturi phenomenon by increasing the wind speed upstream of the aerogenerator 1 and by suction by various depressions generated downstream of the wind turbine. the wind generator 1. During tests, the instantaneous power observed approaches the Betz limit, i.e. 59% of the theoretical power (the theoretical formula in reference being Power in Watts = 1/2 x 1.2 x speeds wind speed in cubic m / s x wind area in m ² ). This instantaneous power observed is to be compared with those obtained with non-ducted wind turbines which are around an efficiency of 15% to 30% and with those obtained with ducted wind turbines comprising a diffuser which can reach 40%, but are rare because difficult to implement.

The present invention is not limited to the embodiments described above but extends to any embodiment falling within the scope of the claims. In particular, the wind generator 1 and the wind tower 0 could advantageously be adapted in size to the operating site, depending on the force of the wind and the needs for electrical energy.

REFERENCES

0. Wind tower

1. Wind generator

2. Fixed structure

2.1. Fairing

2.2. Air intake nozzle

2.3. Conversion device chamber

3. Wind turbine

3.1. Propeller - Blade: 311; Hub: 312

3.2. Axis

4. Electric generator

4.1. Rotor - Element: 411; Ring holder: 412

4.2. Stator - Primary coil: 420a, etc; Secondary coil: 420b, etc.

5. Source of electrical energy

6. Distribution network

7. First electronic regulator

8. Second electronic regulator

9. Sensor

10. Reversing regulator

11. First rectifier

12. Second rectifier

Claims (15)

1. Wind generator (1) comprising: - a fixed structure (2), - a wind turbine (3) comprising a propeller (31) provided with at least two blades (311) and an axis (32) extending integrally from a hub (312) of the propeller and mounted to rotate freely on the structure fixed (2), to convert wind energy into mechanical energy, and - an electric generator (4) comprising a rotor (41) integral with the wind turbine (3) and a stator (42) integral with the fixed structure (2) for converting the mechanical energy generated by the wind turbine (3) into electrical energy, the rotor (41) of the electric generator (4) is fixed on the propeller (31) so as to be at a distance from the axis (32) of the wind turbine (3), the rotor (41) comprises at least one element (411) made from a conductive material and the stator (42) comprises at least one coil (420a, 420b) fixed on the fixed structure (2), so that each element (411) passes nearby of each coil (420a, 420b) on each rotation of one complete revolution of the wind turbine (3) about its axis (32), characterized in that said at least one coil (420a, 420b) comprises at least one pair (420) of coils, each pair of coils comprising: - a primary coil (420a) intended to be connected to a source of electrical energy (5) so that the primary coil (420a) generates a magnetic field when it is traversed by an electrical current supplied by the energy source electric (5), and - a secondary coil (420b) intended to be connected to a distribution network (6) of electrical energy so as to inject into said network an electric current coming from the secondary coil (420b) and generated by disturbances of the magnetic field generated by the primary coil (420a) due to the passage of elements based on conductive material when the rotor rotates. 2. Wind generator (1) according to the preceding claim, wherein said at least one element (411) extends substantially parallel to the axis (32) of the wind turbine (3). 3. Wind generator (1) according to any one of the two preceding claims, wherein the conductive material based on which at least one element (411) is made comprises a mild steel, preferably low carbon. 4. Wind generator (1) according to any one of the three preceding claims, wherein each element (411) has a plate shape having dimensions of 10 to 50 mm, preferably equal to 30 mm, in length, from 5 to 20 mm, preferably equal to 10 mm, in width, and from 0.1 to 2 mm, preferably equal to 0.5 mm, in thickness. 5. Wind generator (1) according to any one of the four preceding claims, wherein the rotor (41) further comprises an annular support (412) fixed to at least one blade (311) of the propeller (31) so concentric with the hub (312) of the propeller (31), said at least one element (411) being fixed to the annular support (412). 6. Wind generator (1) according to the preceding claim, wherein the propeller has a wingspan of between 40 and 100 cm, preferably equal to 60 cm, and supports between 10 and 80, preferably between 40 and 50, elements, the elements (411) being for example distributed at regular intervals on the annular support (412). 7. Wind generator (1) according to any one of the preceding claims, wherein the stator (42) comprises a set of three pairs (420, 421, 422) of coils identical to each other which are for example distributed in a rotational symmetry. relative to the axis (32) of the wind turbine (3). 8. Wind generator (1) according to any one of the preceding claims, wherein each secondary coil (420b, 421b, 422b) is intended to be connected to the distribution network (6) of electrical energy via an electrical contactor (8). configured to open when the wind turbine (3) rotates at a speed greater than a first threshold value. 9. Wind generator (1) according to any one of the preceding claims, comprising three pairs of primary and secondary coils configured so the wind generator produces the three phases of a three-phase current. 10. A wind generator (1) according to any one of the preceding claims, comprising at least two, preferably three, sets of pairs (420, 421, 422, 430, 431, 432, 440, 441, 442) of coils, each assembly comprising at least one pair, preferably three pairs, of coils, and each secondary coil (420b, 421b, 422b; 430b, 431b, 432b; 440b, 441b, 442b) of a pair of coils of an assembly having a area and section different from those of each secondary coil of each pair of coils of each of the other sets. 11. Wind generator (1) according to the preceding claim, further comprising a first electronic regulator (7) configured to successively engage and disengage all or part of each set of pairs (420, 421, 422, 430, 431, 432, 440, 441, 442) of coils as a function of a parameter relating to the wind energy to be converted, for example as a function of the speed of rotation of the wind turbine (3). 12. Wind generator (1) according to any one of the preceding claims, in which the fixed structure (2) comprises a fairing (21) of the propeller (31) which can take the form of a diffuser, the stator (42). being optionally attached to the fairing (21). 13. Wind generator (1) according to any one of the preceding claims, comprising at least one stay (33), each stay (33) being configured between the axis (32) of the wind turbine (3) and a blade (311). ) of the propeller (31) to maintain it in a position substantially perpendicular to the axis (32) of the wind turbine (3). 14. Kit including: - a wind turbine (3) comprising a propeller (31) provided with at least two blades (311) and an axis (32) intended to extend integrally from a hub (312) of the propeller, and - an electrical generator (4) comprising a rotor (41) intended to be secured to the wind turbine (3) and a stator (42) to convert mechanical energy generated by the wind turbine (3) into electrical energy, the stator ( 42) and the wind turbine (3) being clean and intended to be secured to a fixed structure (2), the axis (32) of the wind turbine (3) being mounted freely in rotation on the fixed structure (2) for converting wind energy into mechanical energy, the rotor (41) of the electric generator (4) being intended to be fixed on the propeller (31) so as to be at a distance from the axis (32) of the wind turbine ( 3), the rotor (41) comprising at least one element (411) based on a conductive material and the stator (42) comprising at least one coil (420a, 420b) fixed on the fixed structure (2), so that each element (411) passes near each coil (420a, 420b) on each rotation of a complete revolution of the wind turbine (3) around its axis (32), said at least one coil (420a, 420b) comprising at least one th pair (420) of coils, each pair of coils comprising: a primary coil (420a) intended to be connected to a source of electrical energy (5), and. a secondary coil (420b) intended to be connected to an electrical energy distribution network (6), to constitute a wind generator (1) according to any one of the preceding claims when the kit is assembled. 15. Wind tower (0) comprising a wind turbine (1) according to any one of claims 1 to 13.