SE535202C2 - A method and control system for controlling an upstream wind turbine - Google Patents

Abstract

The present invention relates to a method of guiding an upstream wind turbine to a rest position, the method comprising the step of turning a machine housing (2) of the wind turbine (1) to a rest position which is an angle (ot) from a single working position, said angle (ot) being greater than 120 °. The invention also relates to a control system for an upstream wind turbine, said wind turbine (1) comprising a machine housing (2) which at least partially houses a rotor, and wherein said machine housing (2) is arranged in connection with a mast or a blank in such a way that said machine housing (2) is rotatably movable relative to said mast or empty, and said control system is arranged to be able to rotate said machine housing (2) to a rest position and that said rest position is different from a working position of the wind turbine (1), the difference between said rest position and said working position consists of an angle (ot), and where said angle (ot) is greater than 120 °.

Description

535 202 moment of force where the wind tries to turn the turbine, and the stress on both the turbine and the gear brakes that are usually used to hold it in place against the mast or the ground risks damaging the components. If the braking force is completely lost due to such damage, the possibility of locking the turbine in a desired position relative to the site or the mast is lost at the same time, which seriously impedes safe and efficient operation of the plant.

There is therefore a need for a better solution to reduce the stresses to which a wind turbine in a closed position is exposed, while avoiding damage to important components.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to eliminate or at least minimize the above-mentioned problems, which is achieved by a method according to the preamble of claim 1, characterized in that said angle α between a rest position and a working position is greater than 120 ° , preferably greater than 15 °, more preferably greater than 170 °. In this way a stable rest position can be achieved where a rotor shaft of the wind turbine is placed parallel to the wind but where one does not have to use large force or is dependent on a steady power supply to keep the machine housing in this position.

According to one aspect of the invention, the method also comprises the step of holding the machine housing in the rest position. through, the engine housing can either be held in place by means of a gear brake or similar as the reducer swinging movement which can be created by the action of the wind, or by a gear motor which actively moves the engine housing to the desired rest position. It is also conceivable that only the wind itself keeps the wind turbine in the rest position.

According to another aspect of the invention, the method also comprises the step of continuously sensing a change in the wind direction and correcting the position of the machine housing accordingly. through, the rest position with the engine housing pointing along the wind direction can be maintained, so that a reduced air resistance can be obtained and the load on the structure of the wind turbine is thereby reduced.

According to a further aspect of the invention, the method also comprises the step of looping at least one rotor blade of the machine housing. As a result, the canal resistance is further reduced, and a lower load on the structure of the wind turbine is obtained. According to another aspect of the invention, the method also comprises the step of locking a rotor of the machine housing in a vertically rotationally symmetrical position. In this way, the force of the wind against the rotor blades can be made symmetrical as far as possible, so that the risk of a torque being created in the gear joint can be reduced. Thanks to this, the machine housing can also be more easily kept in the rest position without increased load on brakes or other components.

According to a further aspect of the invention, the method also comprises the step of achieving the rotation to a rest position by the use of at least one gear motor arranged in connection with the machine housing. In this way, the movement can be performed in a controlled and precise manner, independent of wind strength and other external factors.

According to another aspect of the invention, the method also includes the step of achieving the rotation to a resting position by using the wind's own force. This saves on the energy consumption that would otherwise be required to control the rotation in other ways, and the system can be made fault-proof so that the rest position is assumed even if the stop from the operating position occurs due to a fault that causes a power failure or the like.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail below with reference to the accompanying drawings, in which: Fig. 1 shows a schematic view of a dry embodiment of a wind turbine according to the invention in an operating position, and Fig. 2 shows a schematic view of the wind turbine in Fig. 1 in a rest position.

DETAILED DESCRIPTION OF THE DRAWINGS Fig. 1 shows a schematic view of a preferred embodiment of an upstream wind turbine l according to the invention seen from above. The wind turbine 1 comprises a machine house 2 which is located directly on top of a mast or a tower (not shown). Said machine housing 2 houses at least in part a rotor comprising a hub 4 to which at least one, preferably two or three, rotor blades 3 are attached. By rotating said rotor blade 3, the energy is captured in a wind blowing at the wind turbine in the form of kinetic energy which, with a generator placed inside the machine housing 2, converts this motion into electrical energy for use directly in an electricity network or for storage. or similar. In the direction the wind direction is shown with an arrow 5 and a shaft A extending along the engine housing 2, and in this driving position the hub 4 of the engine housing and the rotor blades 3 are positioned so that the hub 4,535,202 points substantially straight towards the wind. This position can be called a working or operating position of the wind turbine 1.

The fact that the wind turbine 1 is referred to as an upstream wind turbine means that the rotor with the rotor blades 3 and the hub 4 during operation is positioned so that a tip of the hub 4 is directed towards the wind, as shown by the operating position shown in Fig. 1. The opposite is a downstream wind turbine where the rotor blades are partially shielded by the machine housing.

Fig. 2 shows a schematic view of the same wind turbine, where the wind turbine is in a rest position. The hub 4 with the rotor blades 3 is now turned so that it points along the wind direction, ie along the axis A but away from the wind. This change of position means a rotation in the girder direction, i.e. substantially horizontally, of the machine housing 2 which results in an angle α of the rotor in the rest position, ironed with said rotor position in the dri fi position, which is at least 120 °, preferably at least 150 °, more preferably at least 170 ° but ideally about 180 ° ironed with the operating position in Fig. 1.

The drive of the wind turbine 1, in particular with regard to the change from a drive position to a rest position, will now be described in more detail.

When operating the wind turbine, the machine housing 2 is generally angled towards the wind, as shown in Figs. 1, so that the direction of the wind, shown by the arrow 5, runs substantially parallel to the machine housing 2 along an axis A. The rotor blades 3 are in this position substantially orthogonal to this wind direction, and a high lu fi resistance can thereby be achieved. By selecting a suitable angle of the rotor blades 3, a rotational speed can be selected which is favorable for generating electric current. A wind direction sensor for shielding the wind direction (not shown) can be provided in connection with the rotor blades 3, in connection with the machine housing 2 or in some other way in connection with the wind turbine 1.

For example, by regularly measuring the direction of the wind, the machine housing 2 can be rotated so that the most favorable angle to the wind can be achieved and the position thereby obtained can be called the working position of the wind turbine.

At certain times, it may be advantageous not to have the wind turbine l in operation. These may be periods of time where the wind speed is too low or too high for power plant 1 to be able to operate, planned rest periods to perform maintenance or repairs on power plant I, or emergency stops due to accidents or injuries. In such a situation, it is advantageous to place the wind turbine in a rest position where the load on the power plant 1 itself, including the empty or mast holding the engine house 2, is lower than when the plant is in operation, and where one can be sure that the power plant 1 is at rest so as not to risk unplanned rotation of the rotor blades 3 or unwanted movement of the machine housing 2. In these positions a control system of the wind turbine 1 can be arranged to bring the machine house to the desired rest position in a number of steps as soon as possible.

In a first step, the rotor blades 3 are decelerated by looping the blades fl so that they provide minimal, or at least substantially reduced, air resistance. A brake system such as a mechanical or electronic brake can also be used to ensure that the movement stops to a rest position where the rotor blades 3 do not move at all in relation to the machine housing 2. When the blades are thus stationary, they can be locked by a suitable vertical blade lock. symmetrical position, such as vertical or horizontal if the power plant 1 has two rotor blades 3, or with one of the blades straight up or down if the power plant 1 has three or eller rotor blades 3, etc. Due to this symmetrical position, the force of the wind against the rotor blades 3 becomes oxygen metric around a vertical axis, which minimizes the risk of a torque arising due to an uneven wind force on different parts of the rotor or rotor blades 3.

After the rotor blades 3 have thus been braked in and started in a desired position, yaw motors or similar systems are used to control the machine housing 2 in the yaw joint so that it is placed in a position with the hub 4 away from the incoming wind, as shown in Fig. 2. and where the angle α with respect to the position in Fig. 1 amounts to about 180 °. In this position, gear brakes can be used to operate the engine housing 2 in this position, or the engine housing 2 can be held in place by the wind's own force or in any other suitable manner. When the rest position is occupied, no applied force, in the form of energy of the gear motors, for example, is needed to keep the power plant 1 in this position, which is well suited for long periods of rest or for emergency stops where the entire power plant 1 has been de-energized. If gear brakes are used during a planned stop, you can regularly continue to shield the wind turbine and let the engine housing 2 gear in accordance with this and then be locked again in the desired position.

In the event that an emergency stop is required, the system for bringing the wind turbine 1 to the rest position can be designed purely mechanically so that the movement from drive position to rest position is possible even if the entire plant is without electricity. By means of a fail-safe brake, the rotor blades 3 can be braked in and locked in a looped, symmetrical position, and the rotation of the machine housing 2 to the position where a approaches 180 ° can be effected by releasing gear brakes or similar component which holds the machine housing 2 in place. that the machine housing 2 can move freely. Due to the influence of the wind, said machine housing 535 202 2 will then be rotated until the rest position is reached, either clockwise or counterclockwise, depending on what means the simplest rotation. When the rest position has been reached, the wind itself can hold the machine housing 2 in this position until it is again desired to resume operation of the power plant 1, for example by starting gear motors or the like.

During the movement from drive to rest position, the speed of the rotation, especially if the rotation as such is controlled by the force of the wind, can cause the machine housing 2 to swing past the rest position so that correction is required to turn it back, but such corrections can also be made by the wind itself. . If desired, any braking factor, such as a gear brake that is actively used or automatically applied in the event of an emergency stop, can be used to slow down the rotational movement so that such an overhang does not occur or so that this becomes significantly less than would otherwise be the case. Even after the rest position has been reached, such a pivoting movement or overturning can occur, and to reduce this, gear brakes can be applied for all or part of the time when the wind turbine is in its rest position.

The steps described above for bringing the wind turbine 1 to a rest position can be performed in a different order than the one described above, or integrated so that your steps are performed simultaneously.

For example, a bending of the blades 3 can take place simultaneously with a turning movement of the machine housing 2.

It should be noted that the angle α can be measured both clockwise, as shown in Fig. 2, and counterclockwise, but that the degrees given above are intended to be applied to the one of these clockwise and counterclockwise angles which is the smallest. An angle of 270 ° clockwise from the operating position then means that the same position gives an angle of 90 ° counterclockwise, which means that the angle α gets the smaller of these degrees, ie 90 °. This angle is thus smaller than the guideline values stated as suitable for a resting position within the scope of the present invention.

The invention is not limited by the above-described preferred embodiments, but may be varied within the scope of the appended claims, as will be appreciated by those skilled in the art. For example, the components can be integrated with each other or varied in their design and location, and the steps used to bring the wind turbine to a rest position can be performed in different order or integrated so that steg your steps take place simultaneously.

The method can also be initiated in various ways, for example by lack of power or other emergency, by a controlled signal from a control system or at fixed times, for example, and different types of motors or brakes can be used to create a wind movement at the wind turbine.

Claims (1)

A method for controlling an upstream wind turbine to a rest position, said wind turbine (1) comprising a machine housing (2) arranged in connection with a mast or a tower, and wherein a rotor comprising at least one rotor blade (3) is arranged in connection with said machine housing (2), the method comprising the step of: turning the machine housing (2) of the wind turbine (1) to a rest position where a hub (4) ) of said machine housing (2) is turned away from the wind, which differs an angle (a) from a working position, where said angle (a) is greater than 120 °, and wherein the method is characterized in that the wind turbine (1) is actively retained in said rest position by a yaw motor and in that the method also comprises the step: before step a) locking the rotor of the wind turbine (1) in a vertically symmetrical position so that the rotor is located in said vertically symmetrical position while the machine housing is rotated to said rest position. tion. A method according to claim 1, wherein said angle α is greater than 150 °. . A method according to claim 1 or 2, wherein said angle ot is greater than 170 °. A method according to any one of the preceding claims, wherein the method also comprises the step of: fl looping at least one rotor blade (3) of the wind turbine (1). A method according to any one of the preceding claims, wherein the method also comprises the step of: achieving the rotation in a) by using at least one yarn motor arranged in connection with the machine housing (2). A method according to any one of claims 1-4, wherein the method also comprises the step: to achieve the rotation in 1) by using the wind's own force by said gear brake releasing so that the machine housing (2) can move freely. A control system for an upstream wind turbine, said wind turbine (1) comprising a machine housing (2) arranged in connection with a rotor, and wherein said machine housing (2) is arranged in connection with a mast or a tower in such a way that said machine housing (2) is rotatably movable relative to said mast or tower, said control system being arranged to be able to rotate said machine housing (2) in a girder position to a rest position. where a hub (4) of said engine housing (2) is turned away from the wind, wherein said rest position is different from a working position of the wind turbine (1) and the difference between said rest position and said working position is an angle (a) greater than 120 °, and characterized in that said control system comprises at least one yaw motor which is arranged to actively hold said machine housing (2) in said rest position, and said control system also comprises locking means arranged to lock said rotor ie tt in vertical direction rotationally symmetrical position. A control system according to claim 7, wherein said angle (α) is greater than 150 °. A control system according to claim 7 or 8, wherein said angle (a) is greater than 170 °. A control system according to any one of claims 7-9, wherein said control system comprises at least one gear brake which is arranged to keep said machine housing (2) in said rest position by counteracting undesired rotation of said machine housing (2) relative to said mast or empty. A control system according to any one of claims 7-10, wherein said control system comprises looping means for looping at least one rotor blade (3) of said rotor. A control system according to any one of claims 7-11, wherein said control system also comprises at least one gear motor arranged in connection with said machine housings (2) and said mast or empty, and wherein said gear motor is arranged to rotate said machine housing (2) relative to said machine housing. mast or empty so that said resting position can be achieved. A control system according to claim 7, wherein said control system is arranged to, by said gear brake releasing so that the engine housing (2) can move freely, use the force of a wind in connection with the wind turbine (1) to obtain a rotation of said engine housing (2) in relation to said mast or tower so that said resting position can be achieved.