DE102014204249A1 - Wave energy converter with power source for actuator - Google Patents

Abstract

The invention relates to a wave energy converter (1) for converting energy from a wave movement of a fluid into another energy form, comprising a stator (25) and at least one rotor (11) rotatably mounted around the stator (25) and having at least one energy converter ( 8), wherein the rotor (11) has a coupling body (3), which is adjustably fastened to the rotor (11) by means of an actuator (5), and with a power source for supplying power to the actuator (5), which outputs an energy Component (10a) and an energy-absorbing component (10b), wherein at least the energy-emitting component (10a) of a rotating assembly (17) comprising at least the rotor (11) of the wave energy converter (1) is associated.

Description

The present invention relates to a wave energy converter.

State of the art

Wave power plants (wave energy converters) use the energy of ocean waves to generate electrical energy. Newer design approaches use rotating units (rotors), which convert the wave motion into a torque. At these hydrodynamic buoyancy bodies (ie bodies that generate a buoyancy when flowing around, such as buoyancy profiles and / or Flettner rotors using the Magnus effect) can be used as coupling body, by means of which from the oncoming wave buoyancy forces and through the arrangement the coupling body is generated on the rotor a moment which is convertible into a rotational movement of the rotor. By a superimposed flow from the orbital flow of the wave motion and the rotation of the rotor itself buoyancy forces on the coupling bodies, whereby a torque is introduced into the rotor. In sea waves, the water particles move on largely circular so-called orbital orbits (in the form of an orbital motion or orbital flow, whereby both terms are also used synonymously). Here, the water particles move under a wave crest in the direction of propagation of the wave, under the wave trough against the wave propagation direction and in the two zero crossings upwards or downwards. Out DE 10 2011 105 169 A1 . DE 10 2011 105 177 A1 . DE 10 2011 105 178 A1 and DE 10 2011 105 170 A1 In this context, a plant concept is known in which the buoyancy of a flowed-on buoyancy rotor, that is, a coupling body generating a hydrodynamic buoyancy, is converted into a rotational movement. In the GB 2 226 572 A is a wave energy converter with Flettner rotors disclosed.

It is desirable to improve the operation of wave energy converters and / or to reduce the complexity / cost of electricity of the equipment.

Disclosure of the invention

According to the invention, a wave energy converter for converting energy from a wave motion of a fluid into another form of energy with a stator and at least one rotor rotatably mounted around the stator with the features of patent claim 1 is proposed. Advantageous embodiments are the subject of the dependent claims and the following description.

Advantages of the invention

A particular aspect of the invention is the measure, in a wave energy converter at least one energy-emitting component of a power source for powering an actuator for a coupling body, which is adjustable, in particular rotatable, attached to the rotor by means of the actuator, a rotating assembly comprising at least the rotor of the wave energy converter to allocate, ie in or on this assembly. This results in a particularly simple construction and a reduced maintenance susceptibility, especially in view of the harsh conditions on the high seas, since no slip rings or rotary unions for the power supply of the actuator are required. The energy-emitting component of the energy source namely rotates with the actuator. As a result, the operation is improved and / or the complexity / power generation costs are reduced.

The energy source for powering the actuator is preferably an electrical generator having an energy-emitting electrical and an energy-absorbing magnetic components that rotate relative to each other. The energy-emitting component is the winding in which a voltage is induced, and the energy-absorbing component is the component providing the magnetic field. This is a particularly expedient embodiment for many applications.

The rotor advantageously has a largely horizontal rotor axis of rotation. The rotor is advantageously driven by the orbital flow. In other words, by the wave motion of the water, more precisely by its orbital flow, a torque (in the context of this invention referred to as "torque" or "rotor (rotary) moment") is generated which acts on the rotor.

In this context, the term "coupling body" is understood to mean any structure by means of which the energy of an inflowing fluid can be coupled into a rotor movement or a corresponding rotor moment. Coupling bodies can, as explained below, be designed in particular as a lift rotor (also referred to as a "wing"), but also comprise resistance rotors or Flettner rotors (ie cylinders with additional inherent rotation). Coupling bodies from the class of buoyancy runners are particularly preferably used, which, in particular, generate a buoyancy force directed essentially perpendicular to the flow in the case of an inflow at an inflow angle in addition to a resistance force in the direction of the local inflow. This can be for example However, the invention is not limited to such profiles. Particularly preferred Eppler profiles can be used. In the case of a corresponding rotor, the local flow and the associated flow angle result from an overlay of the orbital flow and a local or instantaneous wave approach direction, the rotational speed of the lift rotor on the rotor and the angle of attack of the lift rotor.

According to one embodiment, the actuator of the actuator is adapted to adjust an angle of incidence of the coupling body. As a result, the orientation of the coupling body can be optimized with regard to the locally prevailing incident flow conditions.

According to a further embodiment, the actuator of the actuator is adapted to adjust a coupling body geometry of the coupling body. For this purpose, the coupling body may e.g. Flaps similar to those on aircraft wings and / or be designed to change the buoyancy profile geometry (so-called "morphing") to influence the flow.

According to another embodiment, the actuator of the actuator is configured to rotate the coupling body at a desired rotational speed. As a result, Flettner rotors can be used as a coupling body.

According to a further embodiment, the actuator is adapted to change the position of the coupling body relative to the lever arm, in particular the radial distance. By changing the radial distance, the machine can be adapted to different shaft conditions or protected at very high waves of the coupling body from surfacing. In addition, this can reduce the dimensions of the rotor, which is useful for installation and transportation. By changing the angular position of the rotor arms, for example by folding down the rotor arms, a surfacing of the coupling body can also be avoided and the dimensions can be reduced.

According to a further embodiment, the energy-emitting component has a coil for converting mechanical energy into electrical energy. This achieves with simple technical means that mechanical rotational energy of the rotor can be converted into electrical energy for supplying the actuator. In addition, by continuously changing a magnetic field passing through the coil of the energy-emitting component, for example by appropriate operation of an electromagnet, a current can be induced in the energy-absorbing component even when the rotor is at rest.

According to a further embodiment, the actuator has an electric motor, which is connected in a force-transmitting manner to the coupling body. It is thereby achieved that an electric motor, such as e.g. a stepper motor or a synchronous motor, can be used to adjust the coupling body.

According to a preferred embodiment, the actuator is a hydraulic, pneumatic, mechanical or electromechanical actuator.

According to a further embodiment, the rotor has a rotor base and a lever arm extending from the rotor base, wherein the lever arm is hollow. This allows the energy-emitting component and / or the actuator to be arranged at least partially inside the lever arm, which is particularly space-saving and moreover protects the elements arranged there.

According to a further embodiment, the energy-absorbing component of the energy source for supplying energy to the actuator is assigned to the stator of the wave energy converter. This ensures that the actuator further, stationary components, which need not be rotatably arranged with the rotor. Thus, the actuator has a particularly simple and low-maintenance construction.

According to a further embodiment, the energy source for supplying energy to the actuator is designed as an electrical generator with an electrical component as the energy-emitting component and a magnetic component as the energy-absorbing component.

According to a further embodiment, the magnetic component has a permanent magnet. This ensures that no power supply of the magnetic component for providing a magnetic field is required, so that a particularly simple and low-maintenance power source is provided for the actuator.

According to a further embodiment, the wave energy converter to a hollow shaft which extends parallel, in particular concentric to the rotor axis of rotation, wherein in the interior of the hollow shaft, the further component is arranged. This is particularly simple and low-maintenance, and especially space-saving.

Preferably, the wave energy converter has an energy store for the direct or indirect supply of the actuator. This advantageously leads to energy being available even when the rotor is at a standstill, for example, when using Flettner rotors as a coupling body, to first bring this to a certain speed before the rotor starts to rotate.

According to an alternative, the energy store is assigned to the stator. This has the advantage that the energy storage, which usually has a relatively high mass, does not have to be co-rotated. The power supply of the actuator can be done in this case via the energy-emitting component and the energy-absorbing component, when the first is designed as a coil and the second as an electromagnet.

According to another alternative, the energy store of the rotating assembly comprising at least the rotor of the wave energy converter is associated. This results in a simpler construction, since no electromagnet for the power supply of the actuator is required.

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.

The invention is illustrated schematically by means of exemplary embodiments in the drawing and will be described in detail below with reference to the drawing.

figure description

1 shows a preferred embodiment of a wave energy converter according to the invention with two coupling bodies in a perspective view.

2 shows two rotors for converting energy from a wave motion with disc-shaped rotor bases in a perspective view.

3 shows a schematic sectional view of a quadrant of the wave energy converter with an actuator according to a first embodiment.

4 shows a schematic sectional view of the wave energy converter with an actuator according to a second embodiment.

Detailed description of the drawing

In the figures, the same or equivalent elements are given identical reference numerals. A repeated explanation is omitted for clarity.

1 shows a wave energy converter 1 with a rotor base 2 , a housing 7 and four each via lever arms 4 at the rotor base 2 attached coupling body 3 , The lever arms 4 are arranged on each rotor side in a basic position at an angle of 180 ° to each other. The wave energy converter 1 is placed below the water surface of an undulating body of water, such as an ocean. The coupling bodies 3 are profiled in the example shown, but can also be designed as Flettnerrotoren, ie cylinder with additional self-rotation. Appropriately, stands for each of the coupling body 3 an actuator 5 with at least one degree of freedom available to change the orientation (eg "pitch angle", ie the angle between chord and tangential velocity) of the respective coupling body and thus to influence the interaction between the body of water and the coupling body. The degree of freedom of the actuators is described here by adjustment parameters (pitch angle). Alternatively, in the case of Flettner rotors as coupling bodies, the rotational speed of the Flettner rotors can also be adapted. The actuators are preferably hydraulic and / or electromotive and / or pneumatic actuators. Preferably, the wave energy converter 1 also sensor technology 6 to capture the current adjustment. The components 2 . 3 . 4 . 5 . 6 are components of a rotor 11 which rotates about a rotor axis x. This is oriented largely horizontally. In normal operation is the rotor 11 completely submerged.

The rotor 11 is relative to the housing 7 rotatably mounted. The housing 7 is rotatably connected in the example shown with a stator of a direct-drive generator to generate electricity, the rotor 11 (here the rotor base 2 ) is rotatably connected to a rotor of this direct-drive generator. It may also be advantageous to provide a gearbox between rotor base and generator rotor. Not shown is an intended attachment of the wave energy converter 1 on the seabed, which can be done for example by a Mooringsystem and preferably by a monopile.

In 2 are two embodiments of the wave energy converter 1 with disc-shaped rotor base 2 shown without lever arm. These each have two coupling bodies 3 on, the one or both sides of the rotor base 2 are stored. The coupling bodies 3 are with the actuator 5 coupled to the active adjustment of the angle of attack of each one of the coupling body 3 are formed. With bilateral mounting of the coupling body 3 the second side can be rotatably mounted, but alternatively it is also a two-sided attachment of the actuator 5 possible. In addition, there are sensors 6 provided for determining the angle of attack.

At the rotor base 2 engages a rotor shaft 9 an energy converter 8th to, in the present embodiment, a directly driven generator 40 . 41 having.

Based on 3 1, in which a section (essentially a quadrant, symmetry axes are shown with dash-dotted lines) of a wave energy converter in a plan view from above, it can be seen that in the present exemplary embodiment the actuator 5 from an energy source with an energy-emitting, here electrical component 10a and an energy absorbing, here magnetic component 10b is supplied.

The electrical component 10a and the magnetic component 10b are formed, together the actuator 5 to supply with electrical energy. For this purpose, the electrical component 10a in the present embodiment, a coil 13 for the conversion of mechanical energy of the rotating rotor 11 in electrical energy, acting on the rotating rotor 11 is arranged while the magnetic component 10b a magnet 14 has, which is fixed to the wave energy converter 1 is arranged. In the present embodiment, the magnet 14 a permanent magnet such as a rare earth magnet consisting essentially of ferromagnetic metals (iron, cobalt, more rarely nickel) and rare earth metals (especially neodymium, samarium, praseodymium, dysprosium, terbium, gadolinium). Yttrium can also play the role of a rare earth metal. Such a magnet is characterized in that it simultaneously has a high magnetic remanence flux density and a high magnetic coercive field strength and thus a high magnetic energy density. Thus induced during operation of the wave energy converter 1 the magnet 14 a magnetic field in the coil 13 , wherein by the relative movement of the coil 13 on the rotor 11 of the wave energy converter 1 in relation to the stationary magnet 14 an electrical voltage in the coil 13 is induced. It can be provided that the magnet 14 alternatively or additionally has an electromagnet, thereby also at standstill of the rotor, the actuator 5 to be able to supply energy. In this case is an energy storage 12 to supply the electromagnet (and thus indirectly to the supply of the actuator 5 ) necessary, which is assigned to the stator expediently. This has the advantage that the energy storage, which usually has a relatively high mass, does not have to be co-rotated. Alternatively or additionally, an energy store 12 ' to supply the actuator 5 be assigned to the rotor.

A converter unit 33 (eg so-called power electronics) converts the in the coil 13 induced electrical voltage and frequency, so that an electrical voltage and frequency is available, with the over a supply line 16 an electric motor 15 of the actuator 5 is supplied with electrical energy to the coupling body 3 force transmitting connected to the angle of the coupling body 3 to change. It is in the present embodiment in the interior of the lever arm 4 the electric motor 15 arranged with the coupling body 3 is connected to transmit power. The 2 shows that the coupling body 3 between every two or more lever arms 4 can be suspended adjustable.

For the radial and axial force transmission between a rotating assembly 17 , such as the rotor, and a fixed assembly 18 of the wave energy converter 1 , eg the stator, is a (eg media-lubricated) axial and radial bearing 19a . 19b intended.

Furthermore, the fixed assembly includes 18 of the wave energy converter 1 in the present embodiment, a generator winding 40 that with magnets 41 , such as electromagnets or permanent magnets, on the rotor 11 interact inductively and thus allow a conversion of mechanical wave energy into electrical energy. The generator winding 40 and the magnet formed as an electromagnet or permanent magnet 41 can form an external or an internal rotor generator. For cooling the generator arrangement, both the rotating assembly 17 as well as the fixed assembly 18 of the wave energy converter 1 Guide vanes and / or bores (both not shown), which provide a defined flow of coolant, such as water. Further, in the present embodiment, a membrane (not shown) is provided which provides a volume and electrolyte balance between an otherwise sealed medium and the surrounding seawater. The fixed assembly 18 of the wave energy converter 1 may further include other electrical and power electronic components, such as a controller (not in 3 shown) for controlling the actuator 5 , Finally one is transmission element 32 provided, which is to be supported to the seabed to be supported forces and moments in a foundation (not shown) introduced.

In the present embodiment extends parallel and concentric with the rotor axis of rotation x a hollow shaft 20 , which are also part of the rotating assembly 17 is and essentially serves to connect the lever arms. Inside the hollow shaft 20 is a tensioning element 21 arranged, which arranged on both sides of the fixed assemblies 18 combines. The assemblies 18 be here with a kind of mother 31 against a lead 30 of the clamping element 21 braced. It is also conceivable that the driveline is attached only to one side of the machine. On the opposite side of the symmetry axis then only mechanical components would be installed.

The rotor 11 in the present embodiment has two rotor blocks arranged on both sides 34 of which in the 3 only one is shown. At the rotor blocks 34 are the lever arms 4 attached, between which the coupling body 3 are suspended adjustable. The hollow shaft 20 is designed to hold the rotor blocks 34 combines.

Between the rotor blocks 34 and the stator 25 is the axial and radial bearing 19a . 19b intended. The axial and radial bearings 19a . 19b may be sealed to the outside, ie towards the sea. Alternatively, the axial and radial bearings 19a . 19b also be open and thus water lubricated.

The in 3 shown stator 25 of the wave energy converter 1 with the magnetic component 10b is rotationally symmetrical. The rotor 11 with the energy-emitting component 10a is formed in the present embodiment as an external rotor. In other words, when mounting the wave energy converter 1 the stator 25 or are the two modules 18 from both sides in the formed as an external rotor rotor 11 used. For fixing the stator 25 this is with the tensioning element 21 fixed on both sides.

The 4 shows a second embodiment of a wave energy converter, which differs from the first embodiment according to the 3 this distinguishes that in the hollow shaft 20 several components are included. The stator also has a hollow axle in this case 18 , which defines the dash-dotted line of rotation at the same time.

Inside the hollow axle 18 are the magnetic component 10b namely, the magnet 14 , the power source for powering the actuator and the generator winding 40 the energy converter arranged stationary while in the hollow shaft 20 the energy-emitting component 10a namely the coil 13 , the energy source for powering the actuator 5 and the magnet 41 of the energy converter are arranged. Between hollow shaft 20 and hollow axle 18 are radial bearings 19a arranged, which may be open or sealed to the sea. There are expediently also bearings available to absorb axial forces. Furthermore, in the present embodiment, a controller 23 for controlling the wave energy converter in the interior of the hollow axle 18 added.

In operation, as described above, an orbital flow leads to a rotation of the rotor 11 , Thus, the coil rotates 13 into which the fixed magnet 14 induced an electrical voltage. Therefore, electrical energy is available with which the electric motor 15 can be driven to, if necessary, the angle of the coupling body 3 to change, for example, when the flow conditions have changed. Thus, an operation of the wave energy converter 1 with optimal angles of attack of the coupling body 3 possible.

On the other hand, the magnet is rotating 41 , so that in the generator winding 40 a voltage is induced, which can then be removed from the wave energy converter.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011105169 A1 [0002]
• DE 102011105177 A1 [0002]
• DE 102011105178 A1 [0002]
• DE 102011105170 A1 [0002]
• GB 2226572 A [0002]

Claims (12)

Wave energy converter ( 1 ) for converting energy from a wave motion of a fluid into another form of energy, with a stator ( 25 ) and at least one rotatably mounted around the stator rotor ( 11 ), with at least one energy converter ( 8th ), wherein the rotor ( 11 ) at least one coupling body ( 3 ), which by means of an actuator ( 5 ) adjustable on the rotor ( 11 ) and with a power source for powering the actuator ( 5 ), which is an energy-emitting component ( 10a ) and an energy absorbing component ( 10b ), wherein at least the energy-emitting component ( 10a ) of a rotating assembly ( 17 ) comprising at least the rotor ( 11 ) of the wave energy converter ( 1 ) assigned. Wave energy converter ( 1 ) according to claim 1, wherein the actuator ( 5 ) is adapted to an angle of attack of the at least one coupling body ( 3 ) to adjust. Wave energy converter ( 1 ) according to claim 1 or 2, wherein the actuator ( 5 ) is designed to have a coupling body geometry and / or a position of the at least one coupling body ( 3 ) to adjust. Wave energy converter ( 1 ) according to one of the preceding claims, in which the actuator ( 5 ) is adapted to the at least coupling body ( 3 ) to rotate at a desired rotational speed. Wave energy converter ( 1 ) according to one of the preceding claims, in which the energy-emitting component ( 10a ) a coil ( 13 ) for converting mechanical energy into electrical energy. Wave energy converter ( 1 ) according to claim 5, wherein the actuator ( 5 ) an electric motor ( 15 ) connected to the coupling body ( 3 ) is connected to transmit power. Wave energy converter ( 1 ) according to one of the preceding claims, which stores an energy store ( 12 ) for the direct or indirect supply of the actuator ( 5 ) having. Wave energy converter ( 1 ) according to one of the preceding claims, in which the rotor ( 11 ) a hollow lever arm ( 4 ) having the least one coupling body ( 3 ) with a rotor base ( 2 ) of the rotor ( 11 ), wherein inside the hollow lever arm ( 4 ) the energy-emitting component ( 10a ) and / or the actuator ( 5 ) are at least partially arranged. Wave energy converter ( 1 ) according to one of the preceding claims, in which the energy-absorbing component ( 10b ) of a fixed assembly ( 18 ) of the wave energy converter ( 1 ) assigned. Wave energy converter ( 1 ) according to one of the preceding claims, in which the energy-absorbing component ( 10b ) a magnet ( 14 ), in particular a permanent magnet and / or an electromagnet. Wave energy converter ( 1 ) according to one of the preceding claims, in which the wave energy converter ( 1 ) a hollow shaft ( 20 ), which are parallel, in particular concentric, to a rotor axis of rotation (x) of the rotor ( 11 ), wherein in the interior of the hollow shaft ( 20 ) the energy-emitting component ( 10a ) is arranged. Wave energy converter ( 1 ) according to one of the preceding claims, in which the wave energy converter ( 1 ) a hollow axle ( 18 ), which are parallel, in particular concentric, to a rotor axis of rotation (x) of the rotor ( 11 ), wherein in the interior of the hollow axle ( 18 ) the energy absorbing component ( 10b ) is arranged.

Images