JP2006148989A - Wind power generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wind power generation system which eliminates the problem of high cost since the structure of a conventional generator is special and complicated in a conventional small-sized wind generator of such a type that a resistor is connected in series to the internal resistor of the generator via a switch when the number of revolutions of the generator rises above a specified value as measures for prevention of overrevolution of a windmill or a generator at strong wind. <P>SOLUTION: This system is provided with a load system and an overrevolution preventive load system outside a generator controller, and when an overrevolution detection means for a generator detects the overreovlution of the generator, the controller turns on the overrevolution preventive load system which is juxtaposed with the load system. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wind power generation system, and particularly relates to prevention of over-rotation of a small wind power generation system.

Conventionally, wind power generators that generate power using wind power have been constructed around the world as a clean and resource-saving power supply source, and are gradually becoming popular in Japan. As the scale of the apparatus, wind energy from light wind to strong wind can be used, and its output ranges from a small one of about several kW to a large one exceeding several hundred kW. Applications of these small devices include lighting and power sources in mountain and seaside campgrounds and recreational facilities, farms, etc. where general power grids are not widespread.
In such a wind turbine generator, the energy of wind received by the windmill fluctuates greatly, and measures are generally taken to prevent damage caused by excessive rotation of the windmill and generator during strong winds.
As an example, a resistor that is connected to and separated from a generator fixed to a wind turbine shaft via a switch and a controller that controls the switch in accordance with the number of rotations of the generator are provided. When the number is equal to or greater than a set value, a resistor is connected in series to the internal resistance of the generator via a switch (see, for example, Patent Document 1).

JP 2001-103794 A (FIG. 2)

  However, since the structure disclosed in Patent Document 1 is a structure in which the internal circuit of the generator is drawn to the outside and connected to a resistor through a switch, the generator structure becomes special and complicated, and the cost is low. There have been problems such as an increase, obstruction of the standardized structure, and complicated maintenance.

  The present invention has been made to solve the above-described problems, and is a wind power generation system having a configuration capable of connecting an overspeed prevention load in response to fluctuations in wind speed without changing the structure of the generator. The purpose is to provide.

  A wind power generation system according to the present invention includes a windmill, a generator fixed to a rotating shaft of the windmill, a load system that consumes electric power generated by the generator, a control unit that controls a load of the generator, and a generator An over-rotation detection means for detecting the presence or absence of over-rotation, and an over-rotation prevention load system that is loaded by the control unit to become a load when the over-rotation detection means detects over-rotation of the generator, It is equipped with.

  In the wind power generation system according to the present invention, the over-rotation prevention load system is configured so that the over-rotation detecting means for detecting whether or not the over-rotation of the generator detects the over-rotation of the generator so that the control unit loads the generator. Because it is introduced, it is possible to introduce an over-rotation load corresponding to over-rotation without changing the internal structure of the generator, so the generator structure can be simplified and standardized, reducing costs, mass production, and maintenance. Excellent effects such as easy maintenance.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a small wind power generation system 100. This small wind power generation system 100 performs unmanned operation with a relatively small capacity of several kW to several tens kW in mountains, seaside campgrounds, remote islands, etc. where a general power supply network is not installed. is there. In FIG. 1, a generator 11 is fixed to the rotating shaft of the windmill 1. The control unit 50 provided in the generator 11 is provided with a wind turbine controller 2, a dummy load 3, a storage battery 17, a converter 4, and a frequency detection circuit 13 that detects the rotational frequency of the generator 11.
A load 6 of a load system 60 of the generator 11 is provided outside the control unit 50 via a switch 5, and a first overspeed prevention load system 70, a second load system 60 is connected in parallel to the load system 60. An overspeed prevention load system 80 is provided.
The over-rotation prevention load systems 70 and 80 are provided with loads 9 and 10 through switches 7 and 8, respectively.

Next, the operation will be described. The windmill 1 rotates by receiving wind power to drive the generator 11 to generate power. The generated electric power is supplied to the wind turbine controller 2 to charge the storage battery 17 and to supply power to the load 6 by turning on the switch 5 in the load system 60 via the converter 4. In a state where the capacity of the storage battery 17 is fully charged, excess power is consumed by the dummy load 3 under the control of the wind turbine controller 2 in order to prevent overcharging of the storage battery 17.
On the other hand, when the wind speed increases, the rotational speed of the windmill 1 increases in proportion to the wind speed, and the load detection command signal 14 is issued when the frequency detection circuit 13 of the generator 11 detects a set frequency value or more. The load on the generator 11 is reduced by turning on the loads 9 and 10 via the switches 7 and 8 in the first and second over-rotation preventing load systems 70 and 80 provided in parallel to the load system 60. It is increased to suppress over-rotation, and damage due to overspeed of the windmill 1 and the generator 11 is prevented.

  In the example described above, the first and second overspeed prevention loads 70 are provided when two or more overspeed prevention load systems are provided in parallel and the frequency becomes equal to or higher than a predetermined frequency set in the frequency detection circuit 13. However, the present invention is not limited to this, and the over-rotation prevention load system provided in parallel to the load system 60 may be one parallel, or the number of multiple systems of three or more parallels may be used. In the case where the over-rotation prevention load system is two parallels, for example, as shown in FIG. 1, the predetermined frequency set in the frequency detection circuit 13 is set to the first frequency and the second predetermined frequency different from this, and the wind speed is increased. Accordingly, when the first frequency or higher is detected, the first overspeed prevention load system 70 is turned on by the load application command 14, and the wind speed is further increased to detect the second predetermined frequency or higher. At this time, the second overspeed prevention load system 80 is continuously applied by the load application command 15. That is, when the first predetermined frequency is detected, the first overspeed prevention load system 70 is sequentially turned on, and when the second predetermined frequency higher than the first is detected, the second overspeed prevention load system 80 is successively turned on. You may suppress the overspeed of a windmill and a generator.

In the wind power generation system 100 according to the first embodiment, since the over-rotation prevention load system can be provided in a single row or a plurality of systems outside the control unit 50, power generation is performed to connect the over-rotation prevention load. There is no need for the machine to have a special structure, and the generator 11 can be standardized, thereby enabling mass productivity, cost reduction, maintenance maintenance capacity, and the like.
Furthermore, since it is possible to provide a plurality of over-rotation prevention load systems, it is possible to prevent over-rotation of wind turbines and generators corresponding to changes in wind speed due to the day or season of the wind power generation system installation location. It has an excellent effect of being able to.
Furthermore, it is possible to easily increase or decrease the plurality of over-rotation prevention load systems and to adopt a flexible over-rotation prevention measure against a change in wind speed at the time of initial estimation accompanying a change in the environment near the installation location. There is also.

Embodiment 2. FIG.
In the first embodiment, the rotation of the generator 11 is detected by the frequency detection circuit 13 and a load input command is transmitted. Instead, a wind speed detector 18 is provided as shown in FIG. Even when a load input signal is transmitted and the over-rotation preventing loads 70 and 80 are turned on when the wind speed exceeds a predetermined wind speed value set in the wind speed detector 18, the same effect as described above is obtained. Even when a plurality of over-rotation prevention load systems are provided, the first and second predetermined wind speed values are set as in the first embodiment.

Embodiment 3 FIG.
In the third embodiment, as shown in FIG. 3, the joint 16 is provided on the shaft of the windmill 1 that fixes the windmill 1 and the generator 11. When the rotational speed of the wind turbine 1 rises and the wind turbine shaft rotational torque exceeds a predetermined value, the joint 16 mechanically slips and slips, thereby preventing the generator 11 from over-rotating. In this case, the windmill 1 itself is provided with an overspeed prevention device that detects an increase in the rotational speed and prevents the overspeed.
In this case, a wind speed detector 18 similar to that of the second embodiment is provided, and a system in which an over-rotation prevention measure by applying over-rotation prevention loads 70 and 80 is double protected is adopted. Furthermore, instead of the wind speed detector 18, the frequency detection circuit 13 may be provided in the same manner as in the first embodiment, and the over-rotation preventing loads 70 and 80 may be input. A system that does not include the wind speed detector 18, the frequency detection circuit 13, and the over-rotation prevention load systems 80 and 90 may be adopted in consideration of the change in the wind speed at the installation location.

As described above, in the third embodiment, when the rotational torque of the rotating shaft becomes a predetermined value or more, the rotational speed of the windmill and the generator is changed to rotate, and the effect of preventing the damage due to the excessive rotation of the generator can be prevented. is there.
Note that the joint 16 has been described as having a slip generation method with a predetermined torque or more. However, the present invention is not limited to this torque method, and a signal from the frequency detector 13 is received when a predetermined frequency or more is reached, It may be an electromagnetic or hydraulic clutch that receives a signal from the wind speed detector 18 to perform a fixed disengagement operation between the windmill and the generator when the wind speed exceeds the above wind speed, or may be another joint. .

  Embodiments 1 to 3 of the present invention are applicable to a small wind power generation system.

It is a block diagram which shows the small wind power generation system of Embodiment 1 of this invention. It is a block diagram which shows the small wind power generation system of Embodiment 2 of this invention. It is a block diagram which shows the small wind power generation system of Embodiment 3 of this invention.

Explanation of symbols

1 windmill, 5, 7, 8 switch, 6 load, 9,10 over-rotation prevention load,
DESCRIPTION OF SYMBOLS 11 Generator, 13 Frequency detection circuit, 16 Joint, 18 Wind speed detector, 50 Control part, 60 Load system, 70,80 Overrotation prevention load system, 100 Small wind power generation system.

Claims (6)

A windmill, a generator fixed to the rotating shaft of the windmill, a load system that consumes power generated by the generator, a control unit that controls the load of the generator, and whether or not the generator is over-rotated And an over-rotation prevention load system that is loaded by the control unit to become a load when the over-rotation detecting unit detects over-rotation of the generator. Wind power generation system characterized by that. The over-rotation detection means comprises a frequency detection circuit that detects a rotation frequency of the generator, and when the frequency detection circuit detects a frequency equal to or higher than a predetermined frequency, the controller causes a load on the generator. The wind power generation system according to claim 1, wherein the over-rotation prevention load system is introduced. The over-rotation detection means is composed of a wind speed detector, and when the wind speed detector detects a wind speed higher than a predetermined wind speed, the control unit loads the over-rotation prevention load system so that the generator is loaded. The wind power generation system according to claim 1. The wind power generation system according to claim 1, further comprising a plurality of over-rotation prevention load systems. The over-rotation detection means detects the degree of over-rotation, and has a plurality of predetermined values for the degree of over-rotation, and any of the over-rotation prevention load systems has any of the predetermined When the over-rotation detecting means detects an over-rotation of a degree equal to or greater than the predetermined value, the control unit inputs the over-rotation prevention load system corresponding to the predetermined value. The wind power generation system according to claim 4. The rotating shaft of the windmill that fixes the generator is rotated by changing the number of rotations of the generator side and the windmill side when the rotational torque of the rotating shaft exceeds a predetermined value, and the rotating shaft 2. The wind power generation system according to claim 1, further comprising a joint that rotates the generator side and the windmill side at the same rotational speed when the rotational torque of the wind turbine is less than a predetermined value.

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