JP2001268994A - Wind force generated power controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of a difficulty in use of a wind force generator in a residential area due to noise increase of the generator at a strong wind time. SOLUTION: An output voltage of a converter 3 connected to an output stage of the wind force generator 1 is raised at the strong wind time to increase a load current. The generator 1 is electromagnetically braked to suppress an acceleration in the rotting speed of the generator. Thus, when a limit in the speed is not sufficient, a rotating speed limiting load 11 is connected to an output line of the generator 1. To prevent a noise at night, a limiting level of the speed at night is set lower than a limiting level in the daytime.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind power control device capable of limiting the rotation speed of a wind generator when power is supplied to a load by the wind generator.

[0002]

2. Description of the Related Art A typical wind power generation system includes a wind power generator, a rectifier circuit, a converter, an inverter, and a load, and is connected to a commercial power supply system. In this type of wind power generation system, when the power generated by the wind power generator increases rapidly due to an increase in wind speed, the power supply from the wind power generation system to the commercial power supply system rapidly increases, and the voltage and frequency of the commercial power system fluctuate. There is fear. This variation is suppressed by selectively connecting a fixed resistor to the wind generator.

[0003]

By the way, in order to spread the wind power generator, it is necessary to reduce noise and vibration. The noise and vibration of the wind power generator increase when the wind is strong.

Accordingly, an object of the present invention is to provide a wind power generation control device capable of suppressing noise or vibration during a strong wind.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to solve the above-mentioned object, the present invention provides a rotating speed detecting means for detecting a rotating speed of a wind power generator, and controlling an output current of the wind power generator. Current control means, a limited rotation speed signal generation means for generating a signal indicating the limited rotation speed of the wind power generator, a signal indicating the detected speed obtained from the rotation speed detection means, and the limited rotation speed signal generation means And a comparing unit for comparing the signal indicating the limited rotation speed obtained from the control unit, and sending the comparison result to the current control unit, wherein the current control unit determines that the detected speed is higher than the limited rotation speed. Control means for increasing the output current of the wind power generator so as to suppress an increase in the rotation speed of the wind power generator in response to the output of the comparison means. It is those related to the device.

It is desirable to provide a plurality of limiting rotational speeds as described in claim 2. Further, when the rotation speed is higher than the limit rotation speed, the on-time width of the switch element of the DC-DC conversion circuit is increased to increase the output voltage and increase the output current. It is desirable to electromagnetically brake the wind generator.
It is preferable that an inverter is provided and a load and a commercial power supply connecting means, that is, a commercial interconnection means are connected to the inverter. Further, the output current can be controlled by the DC-AC conversion circuit. It is desirable to provide a storage battery as described in claim 6. It is desirable to provide a rotation speed limiting fixed load as described in claim 7, and to connect it to the generator when the rotation speed exceeds the upper limit rotation speed. It is desirable to provide a means for arbitrarily changing the rotation speed limit. Further, it is desirable to change the limit rotation speed according to the time zone as described in claim 9.

[0007]

According to the present invention, when the rotation speed of the wind power generator becomes higher than the limit rotation speed, the current control means (for example, a DC-DC conversion circuit) increases the output current of the wind power generator. It is planned. As a result, the wind generator is electromagnetically braked, and an increase in the rotation speed is suppressed. Therefore, noise or vibration caused by the wind power generator can be suppressed with a relatively simple configuration. According to the second aspect of the present invention, the rotational speed is limited by the plurality of limited rotational speeds, so that it is possible to smoothly suppress the increase in the rotational speed without a sudden change in the output voltage. According to the third aspect of the present invention, the output current is controlled using the DC-DC conversion circuit, and the rotation speed is limited.
The output current can be controlled without providing a special current control device. Therefore, the rotation speed can be restricted by a simple circuit. When the output voltage of the DC-DC converter is increased, the load current increases, the electromagnetic braking action based on the armature reaction of the wind power generator increases, and the increase in the rotation speed is suppressed. When an inverter is provided as described in claim 4, power can be supplied to an AC load. Further, the same effect as the invention of claim 3 can be obtained when the output current of the wind power generator is controlled by controlling the output voltage of the DC-AC conversion circuit (inverter circuit). . According to the invention of claim 6, the storage battery can be used as a load, and the storage battery can be used as a power supply. Also,
According to claim 7, it is possible to reliably suppress the increase in the rotation speed to the upper limit value. According to the eighth and ninth aspects of the present invention, various limited rotation speeds can be obtained according to the installation environment of the wind power generator.

[0008]

Embodiments and Examples Next, embodiments and examples of the present invention will be described with reference to FIGS.

[0009]

First Embodiment A wind power control apparatus according to a first embodiment of the present invention, as shown in FIG. 1, includes a wind power generator 1, a rectifier circuit 2, an output current control means and a DC-DC conversion means. A DC-DC converter 3 and an inverter 4
A load 5, an interconnection protection device 6, a commercial power interconnection terminal 7,
The vehicle includes a charging circuit 8, a storage battery 9, a rotation control circuit 10, a fixed load 11 for setting an upper limit rotation speed, and a switch 12.

The wind generator 1 is a known alternator having a rotor 14 composed of a permanent magnet coupled to a wind turbine 13 and a stator having a three-phase armature winding 15. In addition,
This alternator may be either an external magnet type or an internal magnet type.

The rectifier circuit 2 as an AC-DC converter connected to the armature winding 15 of the wind power generator 1 is a well-known three-phase bridge type rectifier circuit, and includes a wind turbine 13 and a rotor 14.
The three-phase AC voltage generated in the armature winding 15 based on the rotation of the armature winding 15 is converted into a DC voltage. The output voltage of the rectifier circuit 2 has a relatively low value of, for example, 50 V or less.

The DC-DC converter 3 connected to the rectifier circuit 2 converts the output voltage of the rectifier circuit 2 to a higher voltage (for example, 350 V) and controls the output voltage of the converter 3 to be constant. According to the present invention, the output voltage is adjusted so as to control the output current. Therefore, converter 3 has a function as current control means for limiting the rotational speed according to the present invention, in addition to the DC conversion function. Details of the converter 3 will be described later.

Inverter 4 connected to converter 3
Converts a DC voltage output from the converter 3 into a sine-wave AC voltage having a commercial frequency (for example, 50 Hz), and may be configured by, for example, a well-known bridge-type inverter, a half-bridge-type inverter, or the like.

The load 5 connected to the inverter 4 is an AC load in the wind power generation system. An interconnection protection device 6 connected between the inverter 4 and the commercial interconnection terminal 7 is a switch for disconnecting the wind power generation system from the commercial side when a commercial power supply fails, and various known means necessary for interconnection. including.

The charging circuit 8 connected to the inverter 4 rectifies the output voltage of the inverter 4 or the voltage supplied from the commercial interconnection terminal 7 to charge the storage battery 9. Note that the charging circuit 8 can be connected to the converter 3 as indicated by a broken line, and the storage battery 9 can be charged with the DC output voltage of the converter 3. When the storage battery 9 is not fully charged, the storage battery 9 functions as a load in the wind power generation system. The storage battery 9 is connected to the input terminal of the inverter 4 via a diode 16 as a discharging means in order to supply the power of the storage battery 9 to the load 5. Note that an inverter dedicated to storage battery output may be connected between the storage battery 9 and the load 5.

A rotational speed limiting load 11 for suppressing the rotational speed of the wind power generator 1 to an upper limit value is connected to the rectifier circuit 2 via a switch 12. The load 11 can be connected to the output terminal of the converter 3, the output terminal of the inverter 4, or the output terminal of the armature winding 15.

The rotation control circuit 10 includes a rotation speed detector 17
A standard mode signal generator 18, a day / night switching mode signal generator 19, a limited rotation speed signal generator 20, an upper limit rotation speed signal generator 21, first and second comparators 22, 23, and mode selection switches S1, S2. Consisting of

The rotation speed detector 17 is connected to the output line 15a of the armature winding 15, detects the frequency of the output AC voltage of the generator 1, and generates a speed detection signal Vs having a voltage value corresponding to this frequency. Output. FIG. 2A shows a speed detector 17, in which an AC extraction capacitor 17a and a frequency-
And a voltage conversion circuit 17b. Generator output line 15
The capacitor 17a connected to a extracts an AC component of the generator output voltage. The frequency of this AC component is proportional to the rotation speed of the rotor 14 of the generator 1. The frequency-voltage conversion circuit 17b outputs a voltage proportional to the frequency of the AC component extracted by the capacitor 17a. For example, a VCO (voltage controlled oscillator) or a circuit that forms a pulse corresponding to the AC component and a unit time It counts the number of pulses per hit and outputs a voltage or digital value proportional to the number of pulses. Note that the capacitor 17a can be connected to the output terminal of the rectifier circuit 2 as shown by a dotted line in FIG. Since the output voltage of the rectifier circuit 2 includes a pulsating component proportional to the rotating speed of the generator 1, the rotating speed can be detected by extracting the pulsating component with the capacitor 17a. FIG. 2 (B) is FIG. 2 (A)
FIG. 6 shows another rotational speed detector 17 ′ that can be used in place of the rotational speed detector 17 of FIG. This speed detector 17 '
Has a current detector 17c in addition to the capacitor 17a and the frequency-voltage conversion circuit 17b. Current detector 17c
Is connected to the generator output line 15a and detects the current flowing therethrough. Since the frequency of the generator output current is proportional to the rotation speed of the generator 1, when the frequency is extracted by the capacitor 17a and converted into a voltage by the frequency-voltage conversion circuit 17b, the speed detection signal Vs can be obtained. Note that the current detector 17c is connected to the rectifier circuit 2 as shown by a dotted line in FIG.
And the connection can be changed so as to detect the pulsating component of the rectified output.

The standard mode signal generator 18 generates a standard signal M1 indicating that the rotation speed of the generator 1 is to be restricted in the standard mode. Here, the standard mode is a mode in which the rotation speed is suppressed under the same conditions throughout the day, that is, 24 hours.

The day / night switching mode signal generator 19 has a timer 1
9a, for example, the first daytime from 8:00 to 20:00
For example, a high-level signal indicating the time zone of 20:00 to 8 at night
A day / night switching mode signal M2 including, for example, a low level signal indicating a second time zone of the time is generated. Note that, instead of setting the distinction between the first and second time zones by the timer 19a, the day / night determination can be automatically performed by an optical sensor, solar power generation, or the like, and the day / night switching mode signal can be created.

The standard mode signal generator 18 is connected to a limited rotation speed signal generator 20 via a standard mode selection switch S1, and the day / night switching mode signal generator 19 is connected to a limited rotation speed signal via a day / night switching mode selection switch S2. Connected to generator 20. Switches S1 and S2 are alternatively turned on. Instead of providing the switches S1 and S2, the standard mode signal generator 18 and the day / night switching mode signal generator 19 may be operated alternatively to transmit the signals M1 and M2 alternatively.

The limited rotation speed signal generator 20 generates a limited rotation speed signal Vr1 or Vr2 consisting of a voltage proportional to the limited rotation speed according to a designated mode. As shown in principle in FIG. 3, the limited rotational speed signal generator 20 includes first and second voltage sources 24 and 25 and first and second switches 26,
27, a NOT circuit 28, and an OR gate 28a.
The limited rotation speed signal output line 29 is connected to the first switch 28.
Is connected to the first voltage source 24 via the
The switch 29 is connected to the second voltage source 25. The first voltage source 24 is connected to the first reference voltage V shown in FIG.
Generates r1. The second voltage source 25 generates a second reference voltage Vr2 shown in FIG. First and second voltage sources 24, 2
Reference numeral 5 denotes an adjustable variable voltage source which can generate an arbitrary voltage. Note that the first and second voltage sources 24,
25 is constituted by a common voltage dividing circuit in which three resistors are connected in series between a power supply terminal and a ground, a first reference voltage Vr1 is obtained from a first voltage dividing point of the voltage dividing circuit, The second reference voltage Vr2 can be obtained from the voltage dividing point. Line 30,
31 is connected to the control terminal of the first switch 26 via an OR gate 28a, and the line 31 is connected to the control terminal of the second switch 27 via a NOT circuit 28.
Accordingly, the first switch 26 is turned on when the standard mode signal M1 is supplied to the line 30 connected via the switch S1 to the standard mode signal generator 18 of FIG. It is also turned on when a high level signal indicating the daytime of the day / night switching mode signal M2 is supplied to a line 31 connected to the generator 19 via a switch S2, and the first reference voltage Vr1 is applied to a line 29.
Output to The second switch 27 is turned on when a low level signal indicating the nighttime of the day / night switching mode signal M2 is supplied to the line 31 to apply the second reference voltage Vr2 to the line 2.
9 is output. As is clear from FIG. 5, the second reference voltage Vr2 is set lower than the first reference voltage Vr1.
When the standard mode selection switch S1 is turned on, the first switch 26 shown in FIG. 3 is turned on, and a limited speed signal consisting of the first reference voltage Vr1 is always output to the line 29. When the day / night switching mode selection switch S2 is on, the first switch 2 is turned on during the first time period from 8:00 to 20:00.
6 is turned on, the first reference voltage Vr1 is output on the line 29, and the second switch 27 is turned on for the second time widths from 0 to 8 o'clock and 20 to 24 o'clock, and the second switch 27 is turned on. Reference voltage V
r2 is output on line 29. Note that the first reference voltage V
r1 corresponds to the first limit rotation speed, and the second reference voltage Vr2
Corresponds to the second limit rotational speed.

One input terminal of the first comparator 22 is connected to the speed detector 17, and the other input terminal is connected to an output line 29 of the limited rotational speed signal generator 20. Since the line 29 becomes the first reference voltage Vr1 or the second reference voltage Vr2 as shown in FIG. 5, the rotation speed detection signal Vs obtained from the speed detector 17 is changed to the first or second reference voltage Vr1.
periods t1 to t2, t3 to t4, which are higher than r1 and Vr2,
At t5 to t6 and t7 to t8, a high-level comparison output is obtained on the output line 32, which is sent to the converter 3 and used for suppressing an increase in the rotation speed of the generator 1.

One input terminal of the second comparator 23 is connected to the speed detector 17, and the other input terminal is connected to the upper limit rotation speed signal generator 21. The upper limit rotation speed signal generator 21 generates an upper limit rotation speed signal composed of a third reference voltage Vr3 higher than the first reference voltage Vr1, as shown in FIG. Accordingly, when the rotation speed detection signal Vs becomes higher than the third reference voltage Vr3 as in the period from t5 'to t6' in FIG. 5, the comparator 23 sends a high level output to the line 33 and turns on the switch 12. To control. When the switch 12 is turned on, the load 11 having a relatively small resistance value is connected to the rectifier circuit 2, the output current of the generator 1, that is, the armature current increases, and the rotation speed of the generator 1 is increased by the electromagnetic braking effect due to the armature reaction. Is suppressed. The control by the second comparator 23 occurs when the rotation speed of the generator 1 is not suppressed to a desired value by the control of the converter 3 by the output of the first comparator 22.

As shown in FIG.
It comprises a DC conversion circuit 41 and this control circuit 42. The converting circuit 41 is a well-known boosting converting circuit including a boosting reactor 43, a switch element 44 including a transistor, a rectifying diode 45, and an output smoothing capacitor 46. The switch element 44 is connected between the pair of DC output lines 2 a and 2 b of the rectifier circuit 2 via a reactor 43. The output smoothing capacitor 46 is connected in parallel to the switch element 44 via a diode 45. Therefore,
When the switch element 44 is turned on and off, the capacitor 46
Voltage can be obtained. The conversion circuit 41 is not limited to the circuit shown in FIG. 4, but may be a combination circuit of a bridge-type or half-bridge type inverter and an output rectifying / smoothing circuit, or a single DC-DC converter.

The control circuit 42 turns on the switch element 44.
It forms a switch control signal composed of a PWM pulse for off control, and includes resistors 47 and 48 as voltage detection circuits, a main reference voltage source 49, and an error amplifier 50.
, Main reference voltage source switch 51, and sawtooth wave generation circuit 52
, A comparator 53, an auxiliary reference voltage source 54, and an auxiliary reference voltage source switch 55. Two resistors 47, 48
Is connected between the pair of converter output lines 56 and 57, and an output voltage detection value is obtained at these voltage dividing points 58.

One input terminal of the error amplifier 50 is connected to a voltage dividing point 58, and the other input terminal is connected to a main reference voltage source 49 via a switch 51 and to an auxiliary reference voltage via a switch 55. Connected to source 54.
The switch 51 is turned on when the output line 32 of the comparator 22 in FIG.
To the error amplifier 50. The switch 55 is the switch 51
It is turned on when the line 32 is at a high level, and sends the auxiliary reference voltage Vb of the voltage source 54 to the error amplifier 50. The main reference voltage Va is a reference voltage for normal constant voltage control of the converter 3, and the auxiliary reference voltage Vb is a reference voltage for rotation speed control, and is used to increase the output current of the generator 1. The voltage is preferably set higher than Va by about 0.1 to 5%. In the standard mode, the switch 55 of FIG. 4 is turned on during the period from t5 to t6 in FIG. 5, and the auxiliary reference voltage Vb is input to the error amplifier 50. In the day / night switching mode, the switch 55 in FIG.
4 during the periods t2, t3 to t4, t5 to t6, and t7 to t8.
Is turned on, and the auxiliary reference voltage Vb is input to the error amplifier 50.

The sawtooth generating circuit 52 generates a sawtooth voltage at a frequency (for example, 20 to 100 kHz) sufficiently higher than the frequency of the commercial power supply. The PWM comparator 53 is an error amplifier 50
Is compared with the output of the sawtooth wave generating circuit 52, and the well-known P
A WM pulse is formed and sent to the control terminal of the switch element 44, and the switch element 44 is turned on / off. Instead of providing the auxiliary reference voltage source 55, means for applying a bias voltage corresponding to Vb-Va to the sawtooth wave voltage of the sawtooth wave generating circuit 52 only during the high level period of the line 32 can be provided. By adding a bias voltage to the sawtooth voltage in this way,
The width of the output PWM pulse of the comparator 53 increases, the level of the output voltage of the conversion circuit 41 increases, and the output current of the generator 1 increases. Further, a subtractor is connected between the error amplifier 50 and the comparator 53 so that the correction voltage corresponding to Vb-Va can be subtracted from the error output while the line 32 is at a high level.

The characteristic line A in FIG. 6 shows the maximum amount of power that can be generated by the wind power generator 1 with respect to the wind speed or the rotation speed. As is clear from the characteristic line A, the outputable electric energy increases as the wind speed increases. Although the output power amount increases even if the rotation speed becomes higher than 2200 rpm, in this embodiment, the rotation speed of the generator 1 is limited to a maximum of 2200 rpm in order to prevent noise and vibration. The third reference voltage Vr3 in FIG. 5 corresponds to an upper limit rotational speed of 2200 rpm. The first reference voltage Vr1 corresponds to a rotation speed of about 80 to 99% of the upper limit rotation speed of 2200 rpm. The second reference voltage Vr2 corresponds to a rotation speed of about 60 to 90% of the rotation speed corresponding to the first reference voltage Vr1.

When the rotation speed of the wind power generator 1 is normally limited, the output of the standard mode signal generator 18 is sent to the limited rotation speed signal generator 20 via the switch S1. Assuming that the rotation speed detection signal Vs changes as shown in FIG. 5 and the standard mode is set, the rotation speed detection signal Vs crosses the first reference voltage Vr1 during the period from t5 to t6. As a result, the output of the first comparator 22 becomes high in the section from t5 to t6, and in response to this, the switch 55 of FIG. 4 is turned on, and the auxiliary reference voltage Vb is sent to the error amplifier 50.
Thereby, the width of the PWM pulse output from the comparator 53 is widened, the output voltage of the conversion circuit 41 is increased, the current flowing to the load 5, the current flowing to the storage battery 9, and the current flowing from the commercial interconnection terminal 6 to the commercial side. The current increases. When it is desired to keep the rotation speed of the wind power generator 1 low at night, the day / night switching mode switch S2 is turned on. Thereby, in the case of FIG. 5, the switch 55 of FIG. 4 is also turned on at t1 to t2, t3 to t4, and t7 to t8, the output current of the generator 1 increases, and the increase of the rotation speed is suppressed. . As a result,
Night noise is reduced.

The rotation speed cannot be suppressed to a desired value only by the rotation speed suppression operation based on the output of the first comparator 22,
When the detected rotational speed Vs becomes higher than the third reference voltage Vr3, the switch 12 is turned on by the output of the second comparator 23, the output current of the generator 1 increases, and the increase in the rotational speed is suppressed. . Therefore, in this embodiment, the increase in the rotation speed can be suppressed smoothly and in small increments by both the converter 3 and the auxiliary load 11.

[0032]

Second Embodiment Next, a wind power control device according to a second embodiment will be described with reference to FIGS. However, in FIGS. 7 to 9 showing the second embodiment, the same parts as those in FIGS. 1 to 6 showing the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Further, in the wind power control apparatus according to the second embodiment, many parts common to the first embodiment are not shown, and FIGS. 1 to 6 are also referred to in the second embodiment.

The wind power control device of the second embodiment is
The rotation control circuit 10 of FIG. 1 is modified to the rotation control circuit 10a of FIG. 7, and the control circuit 42 of FIG.
Except that it is modified to 2a, it is formed the same as the wind power control device of the first embodiment.

The rotation control circuit 10a of FIG. 7 has a speed detector 17, a standard mode signal generator 18, and a day / night switching mode signal generator 19 like the rotation control circuit 10 of FIG.
However, the rotation control circuit 10a of FIG. 7 has a limited rotation speed signal generator and a comparison unit different from those of FIG.

In FIG. 7, first, second and third rotation speed detecting reference voltage sources for the standard mode and the daytime in the day / night switching mode are used instead of the limited rotation speed signal generator 20 of FIGS. 24a, 24b, and 24c are provided, and fourth, fifth, and sixth rotation speed detection reference voltage sources 24d, 24e, and 24f are provided for night use in the day / night switching mode. The first, second and third rotation speed detection reference voltages Vr1a, Vr1b and Vr1c of the first, second and third rotation speed detection reference voltage sources 24a, 24b and 24c are set as shown in FIG. It is set so that it becomes higher in order. Fourth, fifth, and sixth rotation speed detection reference voltage sources 24d;
The fourth, fifth and sixth rotational speed detecting reference voltages Vr1d, Vre, and Vr1f of 24e and 24f increase in this order as shown in FIG. It is set to be lower than the reference voltages Vr1a, Vr1b and Vr1c. Note that the reference voltage sources 24a to 24f may be configured by a common voltage dividing circuit composed of a series circuit of resistors having a plurality of voltage dividing points.

The circuit of FIG. 7 includes first to sixth comparators 22a, 22b, 22c, instead of one comparator 22 of FIG.
22d, 22e and 22f. One input terminal of each of the first to sixth comparators 22a to 22f is connected to the speed detector 17, and the other input terminal is connected to each of the reference voltage sources 24a to 24f.
24f. As a logic circuit for selecting one from the outputs of the first, second and third comparators 22a, 22b and 22c, two AND gates 60, 61 and 2
Two NOT circuits 62 and 63 are provided. First A
One input terminal of the ND gate 60 is connected to the first comparator 22a.
, And the other input terminal is connected to the second comparator 22b via the NOT circuit 62. Second AN
One input terminal of the D gate is connected to the second comparator 22b, and the other input terminal is connected to the third comparator 22c via the NOT circuit 63. As a result, the output lines A1, A1 of the first and second AND gates 60, 61
Only one output of the first to third comparators 22a to 22c is obtained on the output line A3 of the second and third comparators 22c.

Fourth, fifth and sixth comparators 22d, 22
AND gates 64 and 65 and NOT circuits 66 and 67 as a logic circuit for selecting one from the outputs of e and 22f.
Are provided. One input terminal of the AND gate 64 is connected to the fourth comparator 22d, and the other input terminal is connected to the fifth comparator 22e via the NOT circuit 66. One input terminal of the AND gate 65 is the fifth input terminal.
, And the other input terminal is connected to NO
It is connected to the sixth comparator 22f via the T circuit 67. Therefore, the output line A4 of the AND gates 64 and 65
, A5 and the output line A6 of the comparator 22f, only one output selected from the fourth, fifth and sixth comparators 22d, 22e, 22f is obtained.

The control circuit 42a shown in FIG. 8 includes the same output voltage detection resistors 47 and 48 as the control circuit 42 of FIG. 4, a normal constant voltage control reference voltage source 49, and an error amplifier 50.
, A switch 51, a sawtooth generator 52, and a PWM comparator 53, and first to sixth rotation control reference voltage sources 71, 72, 73, 74, 75, 76, First to sixth reference voltage changeover switches 77, 78, 79, 80,
81, 82 and first and second mode changeover switches 8
3, 84, OR gate 85, NOT circuit 86 and OR
And a gate 87.

The first to third rotation control reference voltage sources 71 to 71
The voltages Vb1, Vb2, Vb3 of 73 are higher in this order and higher than the voltage Va of the normal reference voltage source 49 for constant voltage control. The voltages Vb4, Vb5, Vb6 of the fourth to sixth rotation control reference voltage sources 74 to 76 also increase in this order and are set higher than the voltage Va of the constant voltage control reference voltage source 49. The first, second, and third rotation control reference voltage sources 71, 72, and 73 are first, second, and third rotation control reference voltage sources.
Are connected in parallel with each other via reference voltage changeover switches 77, 78, and 79, and the first mode changeover switch 8
3 is connected to the negative input terminal of the error amplifier 50. Fourth, fifth and sixth rotation control reference voltage sources 74,
Reference numerals 75 and 76 are connected in parallel with each other via fourth, fifth and sixth reference voltage switching switches 80, 81 and 82, and further connected via a second mode switching switch 84 to the negative input of the error amplifier 50. Connected to terminal. First, second,
Third, fourth, fifth and sixth reference voltage switching switches 7
7, 78, 79, 80, 81 and 82 are turned on when the first to sixth lines A1, A2, A3, A4, A5 and A6 are at a high level. The first to sixth lines A1 to A1 in FIG.
A6 is connected to lines A1 to A6 indicated by the same reference numerals in FIG.

The OR gate 85 shown in FIG.
It is connected to the. Accordingly, when the standard mode signal M1 is provided on the line 30 or the high level day / night switching mode signal M2 is provided on the line 31, the OR gate 85 generates a high level output, and the first mode switching is performed. The switch 83 is turned on. The second mode changeover switch 84 is turned on in response to the high level output of the NOT circuit 86 connected to the line 31. The NOT circuit 86
The second mode changeover switch 84 responds to the output of the NOT circuit 86 only in the day / night changeover mode since the day / night changeover mode selection switch S2 'is connected in series with the switch. The day / night switching mode selection switch S2 'in FIG. 8 is linked with the switch S2 in FIG. 7 and is turned on only in the day / night switching mode.

The normal mode reference voltage switch 51 shown in FIG.
Is connected to the first to sixth lines A1 to A6. Switch 51 is 6
It turns on when the output of the input OR gate 87 is low, and turns off when the output is high.

When the standard mode switch S1 in FIG. 7 is turned on, the first mode changeover switch 83 in FIG. 8 is turned on. When the rotation speed detection signal Vs reaches the first rotation speed detection reference voltage Vr1a of the voltage source 24a as shown at time t2 in FIG. 9, the first comparator 22a in FIG.
Goes high, the first AND gate 60 and line A1 also go high, turning on switch 77 and turning off switch 51 in FIG. As a result, the normal control reference voltage source 49 is disconnected, and the first rotation control reference voltage source 71 is connected to the error amplifier 50 instead. Since the voltage Vb1 of the voltage source 71 is slightly higher than the voltage Va of the voltage source 49, the operation of increasing the output voltage of the converter 3 occurs according to the same principle as in the first embodiment, and the load current of the wind power generator 1 is reduced. The rotation speed of the wind power generator 1 is suppressed from increasing. The reference voltage Vb1 of the voltage source 71 cannot be made much higher than the reference voltage Va of normal constant voltage control in order to prevent the output voltage of the inverter 4 from increasing. Therefore, it may not be possible to suppress the rotation speed to the target value by the first rotation control reference voltage Vb1. In such a case, since the rotation speed detection signal Vs further rises, a high level output is generated from the second comparator 22b, the switch 78 in FIG. 8 is turned on, and the second rotation of the voltage source 72 is performed. The speed control reference voltage Vb2 is supplied to the error amplifier 50. As a result, an operation of increasing the output voltage of converter 3 occurs, the load current increases, and the effect of suppressing the increase in the rotation speed of wind power generator 1, that is, the effect of electromagnetic braking, increases. When the target rotation speed does not reach the target rotation speed due to the second rotation speed control reference voltage Vb2, the output of the third comparator 22c in FIG. 7 goes high, and the third switch 79 in FIG. The third rotation speed control reference voltage Vb3 is the error amplifier 5
0, the operation of increasing the output voltage of the converter 3 occurs, the load current increases, and the increase in the rotation speed is suppressed. As described above, the first, second and third comparators 22
If the output voltage of converter 3 is increased stepwise by the outputs of a, 22b, and 22c, a sudden change in the output voltage does not occur, and disturbance in interconnection with the commercial power supply can be prevented. When the rotation speed cannot be suppressed below the upper limit rotation speed even by the output of the third comparator 22c, the output of the upper limit rotation speed detection comparator 23 becomes high level, and the switch 12 of FIG. The load current greatly increases, and the rotation speed of the wind power generator 1 is forcibly increased to the upper limit rotation speed (2200 rp).
m) below.

When the day / night changeover mode selection switch S2 in FIG. 7 is on, the line 31 goes high during the first time period from 8 to 20:00 and goes low during the second time period from 20:00 to 8:00. . During the first time period from 8:00 to 20:00, the switch 83 in FIG. 8 is turned on, and based on the outputs of the first, second and third comparators 22a, 22b, 22c as in the standard mode. First, second and third rotation speed control reference voltages V
b1, Vb2, and Vb3 are selected, and the same rotation speed control as in the standard mode occurs. During the second time period from 20:00 to 8:00, the output of the NOT circuit 86 in FIG. 8 goes high, the switch S2 'is turned on, and the switch 84 is turned on. In this state, for example, at time t1 in FIG. 9, the output of the fourth comparator 22d in FIG.
Is turned on, the fourth rotation speed control reference voltage Vb4 is supplied to the error amplifier 50, and the same rotation speed control operation as at time t2 in FIG. 9 occurs.

In FIG. 9, the upper limit rotation speed at night from 20:00 to 8:00 is the same as that during daytime. However, a comparator for detecting the upper limit rotation speed at night is provided independently, and is higher than the reference voltage Vr3 in FIG. A low reference voltage may be provided to the nighttime upper limit rotational speed detection comparator.

[0045]

Third Embodiment Next, a wind power control apparatus according to a third embodiment will be described with reference to FIGS. However,
10 and 11, substantially the same parts as those in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted. The third embodiment also refers to FIGS.

The wind power control device shown in FIG. 10 is a converter 3 which is a modification of the converter 3 and the inverter 4 shown in FIG.
a, except that an inverter 4a is provided. The converter 3a in FIG. 10 is formed in the same manner as in FIG. 4 except that the reference voltage source 54 and the switch 55 are omitted from the converter 3 in FIG. The inverter 4a of FIG. 10 is obtained by adding a rotation speed control system to the inverter 4 of FIG. 1, and includes a DC-AC conversion circuit 91 and a control circuit 92 as shown in principle in FIG. The conversion circuit 91 is a well-known circuit comprising switches Q1 to Q6 and a filter 93 which are bridge-connected to the DC output line of the converter 3a. FIG. 11 shows a three-phase conversion circuit 91.
However, a single-phase conversion circuit can of course be used.

The control circuit 92 controls ON / OFF of the switches Q1 to Q6 so as to keep the output voltage of the filter 93 constant, and also controls the switches Q1 to Q6 so as to limit the rotation speed of the wind power generator 1. A voltage detecting circuit 94, a reference voltage source 49a for constant voltage control, an error amplifier 50a, a switch 51a, a sawtooth wave generating circuit 52a, a PW
M pulse comparator 53a and rotation speed control reference voltage source 5
4a, switch 55a and sine wave reference voltage signal generator 95
, A multiplier 96 and a control signal forming circuit 97.

The voltage detector 94 shown in FIG.
And outputs it to the error amplifier 50a. FIG.
1 reference voltage source 49a, error amplifier 50a, switch 5
1a, a sawtooth wave generating circuit 52a, a comparator 53a, a rotation speed control reference voltage source 54a and a switch 55a are a reference voltage source 49, an error amplifier 50, a sawtooth wave generation circuit 52, a comparator 53, and a rotation speed control of FIG. It operates similarly to the reference voltage source 54 and the switch 55. The reference voltages Va 'and Vb' of the voltage sources 49a and 54a are the same as the reference voltages Va and Vb of FIG.
Va '<Vb' is set similarly to b. Switch 55a turns on when line 32 of FIG. 10 is high. Switch 51a operates opposite to switch 55a. Therefore, the rotation speed control reference voltage Vb 'is supplied to the negative input terminal of the error amplifier 50a only when the rotation speed of the generator 1 becomes higher than the limit rotation speed. The sine wave reference signal generator 95 generates a sine wave voltage synchronized with the sine wave AC voltage of the commercial interconnection terminal 7. The multiplier 96 adjusts the amplitude of the sine wave reference voltage by multiplying the output of the sine wave reference signal generator 95 by the output of the error amplifier 50a. Comparator 53
The negative input terminal of a is connected to the multiplier 96, and the positive input terminal is connected to the sawtooth wave generating circuit 52a. Sawtooth generation circuit 5
2a generates a sawtooth voltage at a frequency sufficiently higher than the frequency of the commercial power supply.
A PWM-modulated pulse is generated so that a sine wave output voltage can be obtained from a. The control signal forming circuit 97 includes the comparator 5
Based on the output of the switch 3a, the switches Q1 to Q6
Of the on / off control signal.

In the wind power control apparatus according to the third embodiment, when the rotation speed of the generator 1 changes, for example, as shown in FIG. 5, the operation for suppressing the rise of the rotation speed is performed similarly to the first embodiment. Occurs. In short, instead of controlling the output voltage by the converter 3 in the first embodiment, the output voltage is controlled by the inverter 4a in the third embodiment to increase the load current, and the rotational speed is reduced by the electromagnetic braking effect. The rise has been suppressed. Therefore, the same effects as in the first embodiment can be obtained by the third embodiment.

[0050]

[Modifications] The present invention is not limited to the above embodiment, and for example, the following modifications are possible. (1) Even in the case where the rotation speed is controlled by the inverter 4a in the third embodiment, the multi-stage control can be performed similarly to the second embodiment shown in FIGS. (2) The load 11 can be formed as a storage battery without using a resistor. (3) The time width of the daytime zone and the nighttime zone of the day / night switching mode can be arbitrarily changed. (4) A day can be divided into three or more time zones, and a difference can be made between the limit rotation speeds in each time zone. (5) In the embodiment, since the rotation speed detector 17 is configured to detect the rotation speed by an AC or a pulsating component,
Although the configuration is simplified, the rotation of the rotor 14 or the windmill 13 may be optically or electromagnetically detected instead, and a signal indicating the rotation speed may be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a wind power control apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a speed detector.

FIG. 3 is a circuit diagram showing a limited rotation speed signal generator of FIG. 1;

FIG. 4 is a circuit diagram showing the converter of FIG. 1 in detail.

FIG. 5 is a diagram illustrating a relationship between a change in a rotation speed detection signal and a speed limit;

FIG. 6 is a diagram illustrating a relationship between a wind speed and a rotation speed and a maximum output power amount of a generator.

FIG. 7 is a circuit diagram illustrating a speed control circuit of the wind power control apparatus according to the second embodiment.

FIG. 8 is a circuit diagram showing a control circuit of the converter according to the second embodiment.

FIG. 9 is a diagram illustrating a relationship between a change in a rotation speed detection signal and rotation speed control according to the second embodiment.

FIG. 10 is a block diagram illustrating a wind power control apparatus according to a third embodiment.

FIG. 11 is a circuit diagram illustrating the inverter of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wind power generator 3 Converter 4 Inverter 5 Load 10 Speed control circuit 17 Speed detector 22, 23 Comparator

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeru Ito 3-6-3 Kitano, Niiza-shi, Saitama Sanken Electric Co., Ltd. (72) Inventor Shosuke Ito 6-13-19 Akasaka, Minato-ku, Tokyo Zepha Co., Ltd. (72) Inventor Kiyoshi Sato 6-13-19 Akasaka, Minato-ku, Tokyo Zepha Co., Ltd. F-term (reference) 3H078 AA26 BB03 BB07 BB15 CC15 CC22 CC32 CC54 CC66 CC73 5H590 AA06 AA30 AB15 CA14 CC02 CC18 CC24 CD01 CD03 CE05 EA07 EB02 EB12 EB13 EB14 FA08 FB01 FB03 FC21 FC26 GA02 GA10 HA02 HA27 HB06 HB14 JA09 JB06 JB13

Claims (9)

[Claims] 1. A rotation speed detection means for detecting a rotation speed of a wind power generator, a current control means for controlling an output current of the wind power generator, and a limit for generating a signal indicating a rotation speed limit of the wind power generator A rotation speed signal generation unit, a signal indicating the detected speed obtained from the rotation speed detection unit and a signal indicating the limited rotation speed obtained from the limited rotation speed signal generation unit, and comparing the comparison result with the current Comparison means for sending to the control means, wherein the current control means responds to an output of the comparison means indicating that the detected speed is higher than the limit rotation speed to increase the rotation speed of the wind power generator. A wind power control device comprising control means for increasing the output current of the wind power generator so as to suppress it. 2. The limited rotation speed signal generating means generates signals indicating a plurality of limited rotation speeds having different levels, and the comparing means compares the detected speed signal and the plurality of limited rotation speed signals with each other. And a selection output circuit for selectively transmitting outputs of the plurality of comparators, wherein the current control means is selectively provided from the selection output circuit. 2. The wind power control device according to claim 1, wherein the output current level of the wind power generator is changed in a plurality of stages in response to the outputs of the plurality of comparators. 3. The alternator having a rotor composed of a permanent magnet coupled to a windmill, and an armature winding that generates a voltage in accordance with the rotation of the rotor, wherein the wind generator is an AC generator.
The current control means is connected to the AC generator via a rectifier circuit and includes at least one switch element,
A DC-DC conversion circuit configured to exchange a DC voltage level by on / off control of the switch element, and controlling the switch element so that a voltage at an output stage of the DC-DC conversion circuit becomes a predetermined value; and A switch control circuit for increasing the on-time width of the switch element so as to increase the voltage of the output stage in response to the output of the comparison means indicating that the detection speed is higher than the limit rotation speed. The wind power control device according to claim 1 or 2, wherein: 4. An inverter connected to the DC-DC conversion circuit, a load connected to the inverter, and a commercial power supply connecting means connected to an output terminal of the inverter and the load. The wind power control device according to claim 2 or 3, wherein 5. The wind power generator is an AC generator, and the current control means includes a DC-AC conversion circuit connected to the AC generator via an AC-DC exchange circuit, and the DC-AC conversion circuit. The DC-AC conversion circuit is controlled so that the output voltage of the circuit becomes a predetermined value, and the DC-AC conversion circuit is responsive to an output of the comparison means indicating that the detected speed is higher than the limit rotation speed. 2. The wind power control apparatus according to claim 1, further comprising means for controlling the DC-AC conversion circuit so as to increase the output voltage of the wind power. 6. The battery according to claim 2, further comprising a storage battery connected to an output terminal of the DC-DC conversion circuit or an output terminal of the inverter via charging means.
Or the wind power control device according to 3 or 4 or 5. 7. A fixed load for limiting the rotational speed used to suppress an increase in the rotational speed of the wind power generator, and a method for selectively connecting the fixed load for restricting the rotational speed to the wind power generator. Selection connection means, an upper limit rotation speed signal generation means for generating a signal indicating an upper limit rotation speed higher than the limit rotation speed, a detection speed signal obtained from the rotation speed detection means, and the upper limit rotation speed signal generation means And comparing means for controlling the selective connection means to a connection state by a comparison result indicating that the detected speed is higher than the upper limit rotation speed. The wind power control device according to any one of claims 1 to 6, wherein: 8. The wind power control apparatus according to claim 1, further comprising means for arbitrarily changing the rotational speed limit. 9. A time zone signal generating means for generating a time zone signal for setting at least the first and second time zones, each of which is obtained by dividing 24 hours, the first time zone and the second time zone. 9. The wind power control device according to claim 1, further comprising: means for changing the value of the limit rotation speed between the time zones.