WO2009011637A1

WO2009011637A1 - Wind turbine plant with counter rotating turbine rotors and generator

Info

Publication number: WO2009011637A1
Application number: PCT/SE2008/000451
Authority: WO
Inventors: Alf Israelsson
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-07-13
Filing date: 2008-07-14
Publication date: 2009-01-22
Anticipated expiration: 2010-01-13
Also published as: SE531533C2; SE0701710L

Abstract

Conventional wind turbines are limited in their wind absorbing capacity at high wind- forces. This innovation's purpose is to utilize these wind-forces and converting them to electrical energy. Other drawbacks with the conventional wind turbines are the disturbing view and a strong, pulsating noise. The principle for the present innovation is to divide the absorption of the wind energy on a number of counter rotating turbine rotors (6, 7, 8), and to construct the rotors with many blades, made narrow and thin, which to a great extent are winning factors esthetically and acting on its surroundings. An electrical generator (10) with counter rotating magnet- and inductor rotors and double sided air gaps, is integrated with the turbine rotors. Repelling magnetic fields are arranged between the turbine rotors and also by the radially outwards alongside the wings placed magnetic- and inductor rotors, which therefore can be arranged quite close to each other. By placing the wind turbine between two streamlined towers (31, 32), interconnected by bearings for the turbine rotors and rotatable on a firm bedding or sub tower (41), the plant will resist very high bending moments. Together these contrivances mean that the plant can withstand very high wind-forces.

Description

Wind Turbine Plant with Counter Rotating Turbine Rotors and Generator

The invention concerns a wind turbine consisting of in one direction rotating turbine rotors connected at the blade tips, and in the opposite direction an intermediated rotating turbine rotor or turbine rotors. A counter rotating electrical generator is located in the turbine rotors. The electrical generator has, compared with conventional electrical devices, the double amount of slits in the air gaps between magnet- and inductor rotors. Repelling magnetic fields are arranged between the turbine rotors and next to the electrical generators counter rotating magnet- and inductor rotors to minimize the distance between the counter rotating turbine blades and the magnet- and inductor rotors. The turbine rotors are rotationally attached between two in a row oblong towers of streamlined shape, turnably arranged on a stationary sub tower, building or other bedding. The towers are always positioned in the direction of the wind.

Background of the invention

Up till now, wind turbines in different ways must be limited in their wind-absorbing capacities at very strong wind-forces, and the authorities make justified demands at decelerating contrivances in order to approve of the wind turbines being built at all. But it is precisely the strong wind-forces that should be made use of and transformed to electrical power. Partially due to this, present technology has too high manufacturing costs in proportion to the extracted effect and economic dividend. Because of this it is important to construct plants suitable for all types of wind-forces. Among other things, high periphery-speeds of the turbine wheels, one of the consequences of few turbine blades and high wind-speeds, give unsuitable numbers of revolutions with high centrifugal tensions and other disadvantages. Therefore a decrease is desirable to lower periphery-speeds and higher efficiency of the turbine blades. In conventional plants the rotation adjustment of the turbine blades to varying wind-conditions are limited to usually only 1 possibility to turn. A more varied possibility to turn is desirable, all the way from the radially inner parts of the wings to the outer, since they demand very different shifts in pitch angles for the same wind-change.

Other considerable problems are the bothersome view wind turbine plants with two or three wings provide, and a strong and pulsating sound. It is important to also eliminate these annoying inconveniences.

The problem with the generator's need of a high velocity between magnet and inductor is with today's technology usually solved by moving the generator radially outwards from the centre, however, the move is limited by the counterworking and braking torque within the generator which grow with the distance and with the strength of the magnetic field in the gap between magnet and inductor. The gap must also be expanded at the radially out moving, why devices limiting the moving- scale are desirable.

The purpose of the invention and its most essential characteristics

The present innovation is to accomplish wind turbine plants that can satisfyingly function during as good as all wind-conditions, as well full gale as breeze, unlike wind turbines with few blades, and with no surcharge compared to the current technology. The problem is solved by among other things allocating the absorption of the wind's effect to several turbine rotors or steps, and designing the towers to be turnable in such a way that they are always placing themselves in the direction of the wind and withstand much higher bending moments. This is achieved by placing the wind turbine between two oblong, streamlined towers interconnected at the top by bearings for the turbine rotors and at the bottom by a bottom plate turnably attached to a fixed bedding, like bedrock, the upper part of a building, or a stationary tower. The inconvenient view and noise residents are experiencing in areas surrounding by now existing wind power stations are eliminated by building the plant with multiple blades, which in combination with the splitting of the wind turbine in a number of steps, allow for very narrow and thin blades, so that they attract almost no attention at all compared to the view and noise given by current propeller turbines with few blades. Many blades also permit a decrease to lower wing-periphery speeds, down to a third of the rotation speed of the two- or three-bladed at the same blade radius, something that will also significantly reduce the rotation speed at hard wind-conditions. Furthermore, a larger number of blades mean a higher efficiency. Because a lower wing periphery speed results in a combined wider wingspan, i.e. larger wing area, the wind turbine can begin to operate at lower wind-speeds, as the total wing surface against the wind is greater than that of for example a wind turbine with two blades which often has a 8 to 10 times higher wing periphery speed in relation to the wind-speed.

The electrical energy transmission and other cables can be arranged through for example tubular inner centre axles and slip rings.

Because the distance between the counter rotating blades, and therefore turbine rotors, should be minimized, the risk of a collision is compensated by arranging repelling magnetic fields active in the air gaps between the turbine rotors. These magnetic fields can be accomplished by permanent- or electric magnets, or combinations of the two, or by a co-operation with the induced magnetic fields arising from the interaction between the magnets' magnetic fields and induced fields from induction coils or closed circuits integratedly arranged within the turbine rotors. The repelling fields can also be arranged trough interaction between inducing and induced coil circuits, non-closed and closed, power feeded and power generating, according to the principle that when a coil constituting its own electrical circuit is moved across a magnetic field, an electrical current arise in the coil, which in turn build up its own magnetic field, which repel the magnets from the coil. The magnets can also be arranged along the rotor circuit according to Halbach's principle, so that the magnetic fields are weakened on the one side and strengthened on the other side, which is turned toward the air gap.

A mechanical separator for the turbine rotors can also be inserted between the turbine rotors. An example of such are wing-profile shaped plates (61-63) with oblong, flat side areas turned towards adjacent counter rotating plates of similar form, at which point these also in shape are adapted to each other, to maximize the air-accumulation between the counter rotating plates. These turbine rotor separators can be arranged integrated with magnetically repelling turbine rotor separators. When air flow between two plates, the air's speed between the plates cause the static pressure there to be lesser than the outer pressure, wherefore a certain power is needed to further keep the plates apart. This effect reduces the risk for vibratory movements between the turbine rotors.

Apart from the increased velocity for the inductor windings in the air gap between magnet and inductor when the generator is radially moved outwards, a close to doubled relative velocity is achieved for the counter rotating turbine plates by arranging the generator double rotating with counter rotating magnets and electrically generating inductors. The extent of outward moving can hereby be limited significantly.

The counter rotating wind turbine rotors and electrical generators also permit an easy arranging of the double amount of slits in the air gaps between magnet- and inductor rotors compared to conventional constructions of electrical machines.

The electrical generator's magnetic rotors and inductor rotors can be arranged either radially or axially in relation to each other.

Because the air gap between the counter rotating magnets and inductors in the generator usually has to be widened during a radial moving out alongside the wind turbine rotors, this inconvenience can be solved by arranging repelling magnetic fields between or next to the counter rotating generator components. The air gap can thus be minimized, at which the space between the turbine rotors can also be minimizes, at least in the adjacent area.

The generators can be optionally arranged to generate alternating- or direct current, and as an alternative or in combination the outlet of energy can be done via centre axles connected to the turbine rotors.

The repelling magnetic fields, inserted between the turbine rotors and the integrated generator components, entail that the turbine rotors in a natural fashion can be divided into at least three ring formed circle-areas, here named turbine rings, radially placed inside and outside the inserted repelling magnetic field devices and the generator components.

The turbine blades can be attached turnable to be fitted to different wind- conditions by control elements, or as an alternative be attached fixed, or in a combination of these executions. The turbine rings, radially located differently, thus enable various angles of rotation for these.

At a plant with for example three turbine rotors, the electrical generator can be arranged to only two of the counter rotating turbine rotors as the outer rotors are connected at the blade-tips.

Description of the drawings

Fig. 1 shows a vertical cross section of a smaller plant through the wind turbine's main axle, and with alternate transmissions of energy marked.

Fig. 2 shows a sketch of a device of repelling magnets between the turbine rotors in the example of execution.

Fig. 3 shows a rotational axle system at a smaller plant with three turbine rotors.

Fig. 4 shows an outline of an alternately positioning of the counter rotating electrical generator, radially arranged with an air gap.

Fig. 5 shows an outline of the positioning of the counter rotating electrical generator, radially arranged with 2 air gaps.

Fig. 6 and 7 shows a mechanical turbine rotor separator integrated with a magnetically repelling turbine rotor separator, with arrows showing the relative wind direction, incident in relation to the blade speed.

Fig. 8 shows a rotational axle system at a smaller plant with three turbine rotors with the outlet of energy through two internal axles.

Description of examples of execution

Two oblong, streamlined towers (1, 2) standing on a platform (3) arranged rotatable on a stationary bedding shaped as a tower (4). A wind turbine (5) constituting of two in the one direction rotating turbine rotors (6, 7) and an intermediate turbine rotor (8) rotating in the other direction. The outer turbine rotors (6, 7) are interconnected at the blade tips by an outer ring (9). The three turbine rotors are each sectioned into three turbine rings (11-19) radially arranged outside each other. Some turbine blades within the turbine rotors are arranged turnably adjustable in different angles. An electrical generator (10) is arranged between the three turbine rotors' inner turbine rings (11-16), at which, in this example of execution, the magnet- and inductor rotators are arranged in axial directions. In this example of execution the electrical generator's magnetic rotor (21) is attached to the inner turbine rotor (8) and the two inductor rotors (20, 22) are attached to the outer turbine rotors (6, 7). Through this 2 air gaps are obtained between the magnet- and inductor rotors.

In this example of execution repelling magnets (44-50) are, radially calculated from the inside, placed between the second (14-16) and third turbine ring (17-19); u-shaped magnets (44) at the outer turbine rotors (6, 7) with the two poles (45, 46) directed against the centre rotor (8), oblong, staff-formed magnets (47, 48) in two lines at the inner rotor in such a way that the poles (49, 50) are opposite and repelling the outer rotor's magnet poles. In a similar fashion repelling magnets (51, 52, 53) are arranged at the generator's magnet- and inductor rotors (20, 21, 22), at which also the adjacent portions of the turbine rings are held at a suitable distance from each other.

The outer turbine rotors (5, 7) are attached to outer axles (25, 27) rotatably attached to an inner pipe-formed rotatable axle (43). The inner turbine rotor (6) is attached to an intermediate pipe-formed axle (26) and stationary attached to the pipe-formed axle (43), which is rotatably attached to outer bearing units (38, 39) at the two towers' upper parts (33, 34). The transmission of energy can be mechanically torque- transferring through the axle (43) and through one of the two rotatable outer axles (25, 27) and interconnected with outer transmissions (56) to electrical generators (57) but also electrical and optical through cables arranged through the axle (43) and outside the outer axles (25, 27) to outer, fixed positions through slip rings or other transmission devices.

The electrical transmission from the components of the electrical generator and the repelling magnets to an external electrical system can be arranged alternatively through two inner pipes (42, 43) within the pipe-formed rotor axles (25, 26, 27). These inner pipes can also serve as mechanical transmitters of energy from the turbine rotors and be linked with external transmissions (56) to external, stationary electrical generators (57) and also be channels for control-, regulating- and transmission of energy cables for the energy generator system and the repelling magnetic fields.

To surveillance continuous parameters for the wind turbines moving and rotating components and to steer these at varying wind-conditions, separate control- and regulating systems are inaugurated that optimizes the generator- and turbine effect.

Claims

Patent claims

1. Wind turbine plant with the wind turbine arranged with counter rotating turbine rotors which constitute reproductions of the planes of rotation of the turbine blades or wings, at which the blades are arranged with pitch angle regulations, at which the wind turbine is arranged either with conventional electrical generators or with counter rotating magnet- and inductor rotors to generate electricity or with mechanical or hydraulic transmissions of energy, at which the wind turbine is arranged rotatably attached to a turnable upper part of a tower or a rotatable tower, characterized thereby that, at more than two turbine rotors, the first, third, etc. are connected by an outer ring (9) and counter rotating the second, fourth, etc. which are arranged attached to an inner centre axle (43), at which, at for example three turbine rotors (6, 7, 8), the first and third turbine rotor are tied together at the radially outer blade-ends and counter rotating the second, intermediate turbine rotor, that the against each other counter rotating turbine rotors and their blades are kept at a desired distance from each other through turbine rotor separators consisting of in the turbine rotors integrated permanent- or electric magnets (44-48) or circuits of inductance coils or combinations of these arranged in such a way that they generate repelling magnetic fields which keep the counter rotating turbine rotors and their blades at a desired distance from each other.

2. Wind turbine plant according to claim 1, characterized thereby that the turbine rotor separators are consisting of wing-profile shaped plates (61-63) with oblong, flat side areas turned towards adjacent counter rotating plates of similar form, at which these also in shape are adapted to each other, to maximize the air-accumulation between the counter rotating plates, at which these turbine rotor separators are arranged integrated with or without magnetically repelling turbine plate separators.

3. Wind turbine plant according to claim 1, characterized thereby that within the turbine rotors are arranged at least one counter rotating electrical generator (10), i.e. an electrical machine with counter rotating magnet- and inductor rotors (20-22), at which time the electrical generator is integrated with at least one in the one direction rotating turbine rotor and with at least one in the other direction rotating turbine rotor, at which the rotors of the electrical generator are arranged radially and axially in connection to each other.

4. Wind turbine plant according to claim 3, characterized thereby that the electrical generator is arranged with at least two air gaps between the magnet- and inductor rotors.

5. Wind turbine plant according to claims 3 or 4, characterized thereby that the magnet- and inductor rotors (20-22) are held at a suitable gap- distance from each other through repelling magnetic fields, generated by permanent- or electric magnets (51—53) or circuits of inductance coils (or windings) or by combinations of these arranged at or within the generator's magnetic- or inductor rotors.

6. Wind turbine plant according to any of the claims before, characterized thereby that the turbine rotors are divided into two or more by rings circum- and inscribed circle areas, here called turbine rings (11-19), radially arranged inside and outside each other and arranged inside and outside the turbine rotor separator- and electrical generator components, at which the different turbine rings are arranged with separate pitch angle regulations.

7. Wind turbine plant according to claims 1 or 6, characterized thereby that the turbine blades within one or more of the turbine rings are arranged as framework stabilizing bars (54, 55) or cycle spoke like within these.

8. Wind turbine plant according to claim 1, characterized thereby that the tower is divided into, according to the wind direction, a forward streamlined tower (1) and a backward streamlined tower (2) functioning as a guide fin for the adjustment of the wind turbine against the wind direction, at which the two sub towers at their top parts (33, 34) are tied together through the wind turbine's bearing- and energy transmission systems, and in the lower parts are tied together by a common bedding (3) which is rotatingly arranged on a firm bedding, bedrock, the upper part of a building, or sub tower (4).

9 Wind turbine plant according to claim 8, characterized thereby that the tower's centreline of rotation (58) is arranged in front of the turbine's plane of rotation (59) in the, for the wind turbine, most functional wind direction.

10 Wind turbine plant according to claims 1-4, characterized thereby that, at 3 turbine rotors, the transmission of energy from the turbine rotors and the generator (10) and cable connectors to and from the generator and the contrivances for the repelling magnetic fields and the control elements of the pitch angle regulation is arranged through two inner pipe-formed rotatable centre axles (42, 43), at which one is connected with one of the two rotatable outer axles (25, 27) and the other is connected with the middle rotatable outer axle (26), at which the transmission of energy can be mechanically torque transmitting trough the axles (42, 43) or electrically and optically trough cables arranged through these axles.

11 Wind turbine plant according to claims 1 or 3, characterized thereby that the plant is arranged without the electrical generator (10, 20-22) integrated in the turbine rotors, at which the energy outlet from the turbine rotors are arranged through the turbine rotors' rotational axles (42, 43), at which these energy outlet axles can be connected with for example an electrical generator each through step-up gear contrivances (56).

12 Wind turbine plant according to any of the claims 1, 2, 3, 4, 5, characterized thereby that in front of the first turbine rotor (6) of the at the periphery connected turbine rotors, one is arranged with this counter rotating turbine rotor (60) firmly attached to the centre axle (43), at which the counter rotating electrical generator (10) is arranged integrated with these turbine rotors.