RU2788777C1 - Wind turbine speed limiter - Google Patents

Abstract

FIELD: wind energy.

SUBSTANCE: invention relates to wind energy and can be used to stabilize the rotational speed of a wind turbine when the wind speed is higher than the calculated one. The wind turbine speed limiter contains a load placed in the peripheral part of the cavity of each wind turbine blade or the blade swing. The blade swing is mounted with the possibility of rotation in bearings installed at a certain distance from the wind turbine shaft in a head fixedly mounted on the shaft. The swing axis is displaced relative to the axial line of the wind turbine shaft, on which the drum is mounted with the possibility of rotation, mechanically connected on one side with the load, and on the other side through a hinge-lever connection - with a swing. The drum is fixed in a position corresponding to the optimal angle of the blade installation, with a stop fixed on the head, and a counteracting spring attached at one end to the head, and at the other end to the drum. The lever-hinge connection includes the first spherical hinge eccentrically attached to the end of the swing and the second spherical hinge eccentrically attached to the end of the drum connected by a rigid rod.

EFFECT: increasing the load capacity, reducing the required weight of cargo.

1 cl, 1 dwg

Description

The invention relates to wind energy and can be used to stabilize the rotational speed of a wind turbine when the wind speed is higher than the calculated one.

Known wind turbine AVEU6-4M [1, 2] limiting the speed, which is carried out by a centrifugal speed controller direct action. Its disadvantage is that the weights, due to which the rotation of the blades is carried out, are located in close proximity to the center of rotation, their force effect on the blades is directed at an angle to the plane of rotation close to 90 ° due to this, a significant mass of cargo is required to ensure sufficient moment. This also affects the accuracy of the speed limit.

From this shortcoming, the speed limiter of a wind turbine with a horizontal axis of rotation, adopted as a prototype, protected by patent SU 3203 A1, erroneously named as a “ vertical wind turbine” [3], is largely free from this drawback. In it, the blades are attached to the swings, freely rotating in bushings (fig. 1 in the patent), which act as bearings installed at a certain distance from the axis of the wind turbine in the head of the wind turbine rigidly connected to the axis. In the peripheral part of the cavity of the swings of each blade of the wind turbine there is a load (in the patent Fig. 16, 17), which, with the help of a cable (or rod), can turn the drum, loosely mounted on the wind turbine shaft, pulled in the opposite direction by springs attached on one side to the head wind turbine and, therefore, to the axis of the wind turbine, and on the other hand to the fingers extending from the drum.

When the wind increases under the action of centrifugal force, the load overcomes the resistance of the spring and turns the drum. In this case, the drum through a hinge-lever connection (two cylindrical hinges diametrically located on the drum, a V-shaped lever and a second V-shaped lever connected to the swing through two diametrically located cylindrical hinges installed on the swing at a distance from the axis of the wind turbine, exceeding the distance from axis to the bearing) increases the angle of installation of the blade, thereby limiting the speed of the wind turbine. In this case, the levers, since their mutual movement during rotation of the drum is carried out in two planes, are interconnected by means of a spherical hinge.

Since in this limiter the second lever for turning the blade is fixed on the swing at a large distance from the drum, the transfer of force between the drum and the lever is carried out by an intermediate lever of a sufficiently large size, which also works in bending. This forces it to be connected to the drum also with the help of two cylindrical hinges displaced relative to each other by a certain distance. All this increases the dimensions of the central part of the speed limiter, increases the number of moving parts and joints and, as a result, negatively affects the reliability and cost of the product. In addition, since the shoulder for applying the force exerted on the drum from the side of the load is much less than the shoulder for applying the force to the lever for turning the blade from the side of the drum, an increased mass of the load is required for a confident impact on the blade. All this together reduces the operational properties of this speed limiter.

The purpose of the present invention is to improve the operational properties of the wind turbine speed limiter.

This goal is achieved due to the fact that in the wind turbine speed limiter, which contains a load placed in the peripheral part of the cavity of each wind turbine blade or blade stroke, the blade stroke is installed with the possibility of rotation in bearings installed at a certain distance from the wind turbine shaft in a head fixedly mounted on the shaft , while the swing axis is displaced relative to the axial line of the wind turbine shaft, on which the drum is installed with the possibility of rotation, mechanically connected on one side with the load, and on the other hand through a hinged-lever connection - with a swing, while the drum is fixed in a position corresponding to the optimal angle of installation of the blade, with a stop fixed on the head, and a counteracting spring attached at one end to the head, and at the other end to the drum, the lever-hinge connection includes the first spherical hinge eccentrically attached to the end of the swing connected by a rigid rod and the second spherical hinge eccentrically attached to the end of the drum eric hinge.

Schematically claimed wind turbine speed limiter is shown in figure 1.

It contains placed in the peripheral part of the cavity 1 of each blade 2 of the wind turbine load 3. With a specific implementation of the device, for structural reasons, it is possible to place a load in the cavity of the swing 4, mounted with the possibility of rotation in the bearing 5. The drawing shows one tapered plain bearing for each individual blade, installed at a certain distance from the shaft 6 of the wind turbine in a head 7 fixed on the shaft. With a specific design of the device, it is possible to use two radially spaced bearings of various types (ball, roller, cylindrical, conical, single-row, double-row). The axis of the swing 4 is shifted relative to the center line of the shaft 6, on which the drum 8 is mounted with the possibility of rotation, mechanically connected by a rod 9 with a load 3, and on the other hand through a hinged-lever connection - with a swing 4. The lever-hinged connection includes connected by a rigid rod 10 the first spherical hinge 11 and the second spherical hinge 12 eccentrically fixed at the ends of the swing.

The drum is fixed in a position in which the blade installation angle corresponds to the calculated (optimal) installation angle, with a stop 13 fixed on the head, and a spiral spring 14 counteracting in this particular design, attached at one end to the head of the wind turbine, and at the other end to the drum.

The wind turbine speed limiter works as follows. In the initial state, the drum 8 is turned by the force of the spring 14 into the position shown in the figure (counterclockwise until it stops). Since the blades are turned at the calculated installation angle, in the presence of wind, the wind turbine begins to rotate. On loads 3, the centrifugal force acts in this case

F=mω ² R ,

where m is the mass of goods, kg;

ω = π n /30 - angular speed of rotation of the wind turbine, rad/s;

n - speed, rpm;

R is the distance from the axis of rotation of the wind turbine to the center of mass of the cargo, m.

At a rotational speed below the calculated one, this force is insufficient to overcome the resistance force of the spring, so the blades continue to be in the initial (calculated) position. And as soon as the rotation frequency due to increased wind or load shedding on the wind turbine shaft becomes somewhat higher than the specified value, the loads, overcoming the resistance of the spring, will begin to turn the drum (clockwise in the drawing) and through it, by means of rods 10, turn the blades towards the vane position. Since the axes of rotation of the blades and the drum are not parallel, the hinges attached to them are of the spherical type. The coefficient of use of the power of the wind flow when turning the blades decreases, and the increase in the frequency of rotation of the wind turbine with increasing wind speed slows down significantly. It will be maintained practically unchanged the more precisely, the more rigid the static characteristic of the limiter. The limit level is set during the manufacture of the wind turbine or during readjustment during the pre-launch period by changing the force of the spring.

Thus, due to the fastening of the hinges 11 at the ends of the swings in the area between the bearings 5 and the wind turbine shaft in the immediate vicinity of the drum 8 located on the wind turbine shaft, the transfer of forces from the drum to the swings is simplified, the dimensions of the entire force transmission system (drum - hinges - thrust) are reduced , reduces the number of hinges (2 versus 5 in the prototype). The power transmission rods in the inventive speed limiter do not work in bending, like levers in the prototype, but in tension and compression, which increases their load capacity. In addition, to provide sufficient force to turn the blades, a smaller mass of weights is required. This is the beneficial effect of the present invention.

Sources of information.

1. Unified wind power unit type AVEU6-4M. Technical description and operating instructions. - M.: VETROEN, 1986. - 34 p.

2. A.V. Bastron, N.V. Korovaikin, L.P. Kostyuchenko, N.B. Mikheeva, A.V. Chebodaev. Workshop on the use of hydro-wind power plants in agriculture. Ministry of Agriculture of the Russian Federation, Krasnoyarsk State Agrarian University, Krasnoyarsk 2014, pp. 18…21. [Electronic resource]. URL: http://www.kgau.ru/sveden/2017/energo/method_350306_2.pdf

3. Patent SU 3203 A1. IPC F03D 7/02. Vertical wind turbine / Ufimtsev A.G., applicant and patentee Ufimtsev A.G. Application No. 5229, publ. 06/30/1927.

Claims (1)

Wind turbine speed limiter, containing a load placed in the peripheral part of the cavity of each wind turbine blade or blade swing, the blade swing is mounted with the possibility of rotation in bearings installed at a certain distance from the wind turbine shaft in a head fixedly mounted on the shaft, while the swing axis is displaced relative to the center line wind turbine shaft, on which a drum is installed with the possibility of rotation, mechanically connected on one side with the load, and on the other side through a hinged-lever connection - with a swing, while the drum is fixed in a position corresponding to the optimal blade installation angle, with a stop fixed on the head , and an opposing spring attached at one end to the head, and at the other end to the drum, characterized in that the lever-hinge connection includes the first spherical hinge eccentrically attached to the end of the swing and the second spherical hinge eccentrically attached to the end of the drum.

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