JP2000197392A - Wind power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wind power generator in which power can be stored easily and efficiently in a power storage unit, e.g. a battery, regardless of fluctuation of wind power. SOLUTION: When a propeller 220 receives wind power, rotation of the propeller 220 is transmitted to a multipolar generator 230. A connection switching circuit 240 switches connection of respective winding coils of the multipolar generator 230 appropriately in star, delta, series or parallel dependin on the r.p.m. of the propeller 220. When the propeller 220 is rotating at low speed with a breeze, output from each winding coil decreases and the connection switching circuit 240 provides a connection of high voltage low current type. When the propeller 220 is rotating at high speed with strong wind, output from each winding coil increases and the connection switching circuit 240 provides a connection of low voltage high current type. Consequently, the peak value of AC output voltage from the connection switching circuit 240 is kept at a substantially constant level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind turbine generator driven by the rotation of a propeller rotated by wind power.

[0002]

2. Description of the Related Art In recent years, global environmental problems have been taken up as serious problems, and wind power generation has been used as a clean energy supply source. Here, the wind power generation is based on the premise that both the wind power and the wind direction are not constant, and it must be able to supply power stably even when the wind power is weak or under strong wind.

As a conventional wind power generator, a coupling device such as a gear device is provided between a propeller and a generator to adjust the rotation speed of a rotor or change the angle of the propeller facing the wind. As a result, attempts have been made to perform stable power generation in various wind conditions. However, adjusting the rotation speed of the rotor or changing the facing angle of the propeller requires the provision of a coupling device, an angle adjustment device, and the like, which causes a problem that the structure of the wind power generation device becomes complicated.

As shown in, for example, Japanese Patent Application Laid-Open No. 57-208849, a winding constituting a stator of a generator includes a high-speed winding for generating an output of an appropriate frequency during high-speed rotation, and a low-speed rotation. Sometimes a double winding consisting of a low-speed winding that generates an output of an appropriate frequency is used, and the output from the generator is changed to the high-speed side or the output according to the rotation speed so that the output frequency from the generator does not greatly change. There is a wind power generator having an output switching device for switching to a low speed side. However, if the high-speed side winding and the low-speed side winding are wound twice around the electromagnetic pole of the stator, there is a problem that the size of the stator and thus the generator is increased.

Further, as disclosed in Japanese Patent Application Laid-Open No. 9-317626, there is a wind power generator equipped with a multi-pole AC generator having a pole number switching device for switching the number of poles according to the rotation speed of a propeller. However, the above-mentioned pole number switching device attempts to keep the power generation frequency constant, and when the wind power is weak, the power generation voltage cannot be increased, and the battery cannot be effectively stored. There's a problem.

Accordingly, an object of the present invention is to provide a wind power generator that can easily and efficiently store power in a power storage device such as a battery even when there is a strong or weak wind.

[0007]

In order to solve the above-mentioned problems, a wind power generator according to the present invention comprises a rotor having a magnet that rotates with the rotation of a propeller, and a plurality of electromagnetic devices arranged to face the magnet. And a connection switching mechanism for switching connection of a plurality of winding coils provided for each of the plurality of electromagnetic poles.

In the above-mentioned wind power generator, a connection switching mechanism for switching the connection of a plurality of winding coils provided in each of a plurality of electromagnetic poles is provided. Switching the connection of multiple winding coils to generate a predetermined voltage, under strong wind,
By switching the connection of a plurality of winding coils at a predetermined voltage required for power storage and so that the output current becomes large,
Efficient wind power generation can be realized.

The connection switching mechanism switches a plurality of winding coils from a star connection to a delta connection in response to, for example, when the wind power changes from weak to strong, and when the wind power changes from strong to weak. In response to the change, the plurality of winding coils are switched from delta connection to star connection.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG.
It is a block diagram explaining the structure of the wind power generator of an embodiment. This wind power generator includes a propeller 22 that receives wind power.
0, the multipolar generator 2 to which the rotation of the propeller 220 is transmitted
30, a connection switching circuit 240 for switching the connection of the terminals of the respective winding coils constituting the multipolar generator 230, a rectification circuit 250 for rectifying the output of the connection switching circuit 240, and a battery for storing the output voltage of the rectification circuit 250 260, and a rotation sensor 270 for detecting the number of rotations of the propeller 220. Note that the inverter 2 connected to the battery 260
The reference numeral 80 designates the direct current extracted from the battery 260 as 1
Convert to 00V AC.

FIG. 2 is a longitudinal sectional view for explaining the structure of the multipolar generator 230. The shaft 221 connected to the propeller 220 in FIG. 1 is supported on the main body 290 side via a pair of bearings 222. A cylindrical rotator 223 is fixed to the shaft 221.
A four-pole rotor 224 is fixed to the inner peripheral surface of the rotor.
On the other hand, a three-phase six-pole stator 225 is fixed to the outer peripheral surface of the main body 290 so as to face the rotor 224.

FIG. 3 shows a rotor 224 and a stator 225.
FIG. 3 is a cross-sectional view illustrating the arrangement. The rotor 224 has four permanent magnets 224 evenly arranged in four directions on the circumference.
a, 224b, 224c, and 224d. These permanent magnets 224a to 224d are arranged such that the polarity is switched between adjacent magnets. Stator 225
Includes six-pole stator cores Ua, Va, Wa, Ub, Vb, and Wb formed in an equal arrangement in six directions on the outer periphery. Each stator core Ua, Va, Wa, Ub, Vb, W
b, winding coils Ua, Va,
Wa, Ub, Vb and Wb are wound and held there.

FIG. 4 is a diagram for explaining the connection between the stator 225 and the connection switching circuit 240 in FIG. Stator 22
5, the winding coils Ua, Va, Wa, Ub, V
b, a pair of output terminals extending from Wb are connected to the connection switching circuit 2
40, input terminals TUa, TVa, TWa, TU
b, TVb, and TWb. The connection switching circuit 240 includes input terminals TUa, TVa, TWa, TU
b, TVb, and TWb are connected in an appropriate arrangement based on the wind speed state output from the rotation sensor 270, and the three terminals T
Connect to 1, T2, T3.

FIG. 5 is a diagram illustrating the connection between the winding coils Ua, Va, Wa, Ub, Vb, and Wb by the connection switching circuit 240. FIG. 5A shows a three-phase coil in which winding coils arranged opposite to each other are connected in series (that is, first-phase coils Ua and Ub, second-phase coils Va and Vb, and third-phase coils Wa and Wb). Are star-connected. FIG.
(B) shows a three-phase coil (that is, a first-phase coil Ua, Ub, a second-phase coil Va, Vb, and a third-phase coil Wa, Wb) in which winding coils that are opposed to each other are connected in series. Connected. FIG. 5C shows a three-phase coil (that is, the first coil Ua, the second coil Va, and the third coil Wa) connected in a star connection, and another three-phase coil (that is, the first coil Ub, The star-connected second coil Vb and the third coil Wb) are connected in parallel. FIG. 5D shows a three-phase coil (that is, the first coil U) in which the winding coils arranged facing each other are connected in parallel.
a, Ub, second coils Va, Vb, third coils Wa, W
b) is a delta connection.

Although not shown, the connection switching circuit 240 is divided into four stages from a state where the rotation speed signal output from the rotation sensor 270 is the largest to a state where the rotation speed signal is the smallest. A determination unit that generates a corresponding signal; and a switch device that switches a connection according to a signal output from the determination unit. In the first stage in which the rotation speed signal indicates the weakest wind state, the winding coils Ua, V
a, Wa, Ub, Vb, and Wb are switched to the serial star connection shown in FIG. 5A, and in the second stage in which the rotation speed signal indicates the next strong low wind condition, the series delta connection shown in FIG. In the third stage, in which the rotation speed signal is switched to the parallel high star condition in FIG. 5C, and the rotation speed signal is switched to the parallel star connection in FIG. 5 (d) is switched to the parallel delta connection. In other words, the serial star connection in FIG. 5A corresponds to a light wind / low rotation state, and the output from the connection switching circuit 240 is a high-voltage small-current type. On the other hand, the parallel delta connection in FIG. 5B corresponds to a strong wind / high rotation state, and the output from the connection switching circuit 240 is a low-voltage high-current type.

The rotation sensor 270 detects the rotation speed of the propeller 220 without applying a load to the propeller 220. For example, a magnetic ring that rotates with the shaft of the propeller 220 is arranged around the shaft,
Periodic openings are formed in the circumferential direction of the ring. Then, the multipolar generator 2 is disposed so as to face the ring.
The magnetic change at the opening of the ring can be detected by a magnetic sensor fixed to the main body side of the ring 30, and this magnetic change can be converted into the number of pulses to determine the rotation speed of the propeller 220.
It is needless to say that various kinds of rotation measuring devices such as a tachometer can be used instead of the pulse counter using such a magnetic sensor.

Hereinafter, the operation of the wind power generator according to the first embodiment will be described. When the propeller 220 receives the wind,
The rotation of propeller 220 is transmitted to multipolar generator 230. Each winding coil Ua, V provided in the multipolar generator 230
In a, Wa, Ub, Vb, and Wb, wind power, that is, AC power corresponding to the rotation speed of the propeller 220 is generated. On this occasion,
The connection switching circuit 240 controls each winding coil Ua, V according to the rotation speed of the propeller 220 detected by the rotation sensor 270.
The connections of a, Wa, Ub, Vb, and Wb are appropriately switched to star or delta, serial or parallel as shown in FIG. As a result, when the propeller 220 is rotating at a low speed due to the breeze, each of the winding coils Ua, Va, Wa, Ub, Vb,
Although the output of Wb is small, when the connection of the connection switching circuit 240 is of a high voltage and small current type and the propeller 220 is rotating at high speed due to strong wind, each winding coil Ua, V
Although the outputs of a, Wa, Ub, Vb, and Wb are large, the connection of the connection switching circuit 240 is a low-voltage large-current type,
The peak value of the AC voltage output from the connection switching circuit 240 is kept substantially constant. The AC voltage output from the multipolar generator 230 with substantially constant intensity is rectified by the rectifier circuit 250 and supplied to the battery 260 as a DC voltage equal to or higher than a specific threshold necessary for power storage. Battery 260 is gradually charged with a small current when propeller 220 is rotating at a low speed due to light wind, and is rapidly charged with a large current when propeller 220 is rotating at a high speed due to strong wind.

[Second Embodiment] Hereinafter, a second embodiment of the present invention will be described. The wind power generator according to the second embodiment is a modified example of the device according to the first embodiment, and the same portions are denoted by the same reference numerals and the description thereof will not be repeated.

FIG. 6 is a block diagram illustrating the main structure of the wind turbine generator according to the second embodiment. In this wind turbine, the shaft 221 connected to the propeller 220
Are supported by a magnetic bearing 322. That is, the rotor 224 fixed to the inner peripheral surface of the cylindrical rotating body 223 and the main body 29
A magnetic bearing 322 is used as a bearing of the multipolar generator 230 including the stator 225 fixed to the outer peripheral surface of the motor.

FIG. 7 is a longitudinal sectional view showing the magnetic bearing 322 cut along its axis. Housing 100b,
A shaft portion 221 rotatably supported in the shaft 100c is provided with a flange portion 80 that forms a part of a thrust magnetic bearing extending in a radial direction from substantially the center. The rotor core 2 that forms a part of the radial magnetic bearing is fitted to the outer periphery of both ends in the axial direction of the shaft 221. The rotor core 2 is a circumferentially laminated body of I-type magnetic steel sheets, and holding members 3 arranged on the outer periphery of each rotor core 2.
And is fixed to the shaft 221 by the fixing rings 4 on both sides in the axial direction.

Outside the rotor core 2 in the radial direction, four stator cores 10 each of which is a U-shaped electromagnetic steel sheet laminate constituting a part of the radial magnetic bearing are arranged at regular intervals in the circumferential direction with respect to the housing 100b. ing. The stator core 10 suffices if it has three or more. The main body member 10c has an L-shaped cross section and includes a base extending in the axial direction and a yoke extending inward in the radial direction. And a yoke member 10d having an I-shaped cross section. A flat permanent magnet 20 for generating a bias magnetic flux is disposed between the main body member 10c and the yoke member 10d. Yoke part of main body member 10c and yoke member 1
The excitation coils 31 and 32 for adjusting the magnetic flux are wound around 0d, respectively. The surface of the stator core 10 facing the rotor core 2 is an electromagnetic pole. In addition,
The shaft 22 in the housings 100b and 100c
The radial displacement sensors 5 disposed opposite to both ends in the axial direction sense the radial position of the shaft 221.

Further, the magnetic bearing 322 is a part of a thrust magnetic bearing, and is a circle of a magnetic material having a U-shaped cross section which is installed concentrically opposite to both axial sides of a flange portion 80 provided on the shaft 221. An annular body 40, an annular permanent magnet 50 concentrically interposed at a part of the cross section of the U-shaped annular body 40, an exciting coil 60 wound around a groove of the U-shaped annular body 40, and a flange. An axial displacement sensor 70 for sensing the axial position of the section 80.

The annular body 40 is composed of a main body member 40c having an L-shaped cross section including a base portion extending in the radial direction and a yoke extending in the axial direction, and an annular yoke portion extending in the axial direction from the main body member 40c. 40d, and a pair of support members 540
Is attached to the housing 100b via the. In addition, facing one side surface of the outer peripheral portion of the flange portion 80,
An axial displacement sensor 70 is arranged on one support member 540.

Touch-down bearings 100a which do not normally come into contact with the small-diameter portions 221a formed at both ends in the axial direction of the shaft 221 are arranged and fixed to the housing 100c.

In the above-described magnetic bearing 322, a control circuit (not shown) supplies a necessary current to the exciting coils 31, 32, 60 based on the outputs of the displacement sensors 5, 70, so that the shaft 221 floats to a target position. Let it. Such position control can be performed by PID control or modern control theory. Thereafter, the target position signal of the control circuit is changed so that the value of the current flowing through the exciting coils 31, 32, 60 becomes zero. That is, feedback control is performed so that the target position for supporting the shaft 221 matches the position where the attraction force of the permanent magnets 20 and 50 is balanced. In this state, zero current control has been achieved, and the exciting coil 31,
Current hardly flows through 32 and 60. That is, the control current flowing through the exciting coils 31, 32, 60
21 is a very small current of only the differential operation for suppressing the minute fluctuation, and the power consumption of the magnetic bearing 322 is extremely small.

According to the above-described wind power generator of the second embodiment, since the non-contact magnetic bearing 322 is used as the bearing of the propeller 220 and the multipolar generator 230, the maintainability of the bearing portion is good. Energy can be used effectively even when the wind is small.

Although the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the multi-pole generator 230 has four poles and three phases. However, the number of poles and the number of phases can be changed according to the situation such as the installation location of the wind power generator, and the number of coils arranged in parallel Can also be changed as appropriate. At this time, the internal wiring and the like of the connection switching circuit 240 are appropriately changed according to the setting of the number of poles, the number of phases, the number of parallel coils, and the like.

[0028]

As is apparent from the above description, according to the wind power generator of the present invention, the connection switching mechanism for switching the connection of the plurality of winding coils provided for each of the plurality of electromagnetic poles is provided. In weak wind, the connection of a plurality of winding coils is switched so as to generate a predetermined voltage required for power storage even at a low rotation speed of the rotor. By switching the connection of the plurality of winding coils so that the current increases, efficient wind power generation can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a structure of a wind turbine generator according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view illustrating a multipolar generator of the wind power generator of FIG.

FIG. 3 is a cross-sectional view illustrating a structure of the multipolar generator of FIG.

FIG. 4 is a diagram illustrating a connection switching circuit of the wind turbine generator of FIG. 1;

FIG. 5 is a diagram illustrating connection by the connection switching circuit of FIG. 4;

FIG. 6 is a block diagram illustrating a structure of a wind turbine generator according to a second embodiment.

FIG. 7 is a cross-sectional view illustrating a main part of the wind turbine generator of FIG.

[Explanation of symbols]

 5,70 Displacement sensor 10 Stator core 20,50 Permanent magnet 31,32,60 Exciting coil 40 Annular body 220 Propeller 221 Shaft 222 Bearing 223 Cylindrical rotor 224 Rotor 224a to 224d Permanent magnet 225 Stator 230 Multipole generator 240 Connection Switching circuit 250 Rectifier circuit 260 Battery 270 Rotation sensor 322 Magnetic bearing

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiromasa Fukuyama 1-5-50 Kugenuma Shinmei, Fujisawa-shi, Kanagawa F-term in NSK Ltd. (Reference) 3H078 AA02 AA26 BB06 CC22 CC32 CC52 CC57 CC72 5H019 AA04 BB01 BB02 BB05 BB08 BB17 CC04 EE10 FF03 5H590 AA02 CA14 CC02 CC18 CC24 CC32 CC34 CD01 CD03 CE05 EA07 FC26 HA11 HA27 HB12 HB14 JA12 JA13 JA14 5H621 BB10 GA04 GB10 HH02 JK19

Claims (1)

[Claims] 1. A wind turbine generator comprising: a rotor having a magnet that rotates with the rotation of a propeller; and a stator having a plurality of electromagnetic poles arranged to face the magnet, wherein each of the plurality of electromagnetic poles A wind power generator, comprising: a connection switching mechanism that switches connection of a plurality of winding coils provided in the wind power generation device.