JP2001327097A - Power-selling system for wind power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sell power smoothly by linking a wind power generator G, linked with a commercial power system PL. SOLUTION: The power-selling system comprises a limit unit 11 connected to a wind power generator G, a switching unit 12, a matching unit 14, and a battery B to be connected with the output side of the limit unit 11. The limit unit 11 limits the maximum output voltage to the charging voltage of the battery B, the switching unit 12 delivers excessive power P0 of the battery B to the matching unit 14 side, and the matching unit 14 matches the voltage, frequency and voltage waveform before selling a power Pc to a commercial power system PL.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power selling device for a wind power generator, which can link a wind power generator to a commercial power system and smoothly sell generated power.

[0002]

2. Description of the Related Art From the viewpoint of environmental problems, attention has been paid to wind power generators that do not cause air pollution.

[0003] This is configured by combining a battery with a wind power generator that generates power by wind power, and the battery can be charged by the wind power generator and power can be supplied to the load by the battery. In other words, wind power generators tend to fluctuate greatly in generated power due to random changes in wind power.However, once a battery is charged and power is supplied to a load, a small independent power source that is not linked to the commercial power system As a result, the load can be operated stably. In addition, the wind power generator can mechanically or electrically brake the propeller to prevent overcharging of the battery when the wind is strong when the battery is fully charged.

[0004]

According to the prior art, since the power generated by the wind power generator fluctuates randomly due to the wind power, the power quality such as voltage fluctuation, frequency fluctuation, voltage waveform, etc. is required by the commercial power system. There is a problem that it is difficult to maintain the level, and it is difficult to sell power in connection with a commercial power system.

Accordingly, an object of the present invention is to provide a wind power generator by connecting a limiting unit, an opening / closing unit, and a matching unit to a wind power generator and providing a battery on the output side of the limiting unit. It is an object of the present invention to provide a power selling device for a wind power generator that can smoothly sell power in cooperation with a commercial power system.

[0006]

According to an embodiment of the present invention, there is provided a restriction unit connected to a wind power generator, a switching unit, a matching unit, and a battery connected to an output side of the restriction unit. The limiting unit limits the maximum value of the output voltage to the charging voltage of the battery, the switching unit sends surplus power from the battery to the matching unit, and the matching unit matches the voltage, frequency, and voltage waveform. The main point is to sell the power from the switching unit to the commercial power system.

[0007] The switching unit may include a timer element for detecting that the voltage of the battery has dropped below the rated voltage beyond the set time.

[0008] A step-up conversion unit can be interposed between the switching unit and the matching unit.

[0009]

According to the configuration of the invention, the limiting unit can protect the battery by limiting the maximum value of the output voltage to the charging voltage of the battery even when the power generated by the wind power generator fluctuates. On the other hand, the opening / closing unit transmits the surplus power from the battery to the matching unit when the battery is sufficiently charged by the power generated by the wind power generator via the limiting unit and the voltage of the battery is equal to or higher than the rated voltage. And the battery discharge proceeds, and when the battery voltage drops to the rated voltage, the transmission of power to the matching unit is stopped. That is, the switching unit operates only when the voltage of the battery is equal to or higher than the rated voltage to minimize the voltage fluctuation on the input side of the matching unit.
High-quality power can be sold to the commercial power system by matching the voltage, frequency, and voltage waveform of the power from the switching unit to the commercial power system.

However, the charging voltage and the rated voltage here refer to the maximum allowable charging voltage and the minimum allowable terminal voltage when the battery is continuously charged and discharged. When the battery voltage drops below the rated voltage and stops once, the battery is charged via the limiting unit, and the battery voltage recovers to the charging voltage or a set voltage close to the charging voltage. By
It is assumed that the power is automatically restarted and the power transmission is restarted.

A timer element incorporated in the switching unit detects that the voltage of the battery has dropped below the rated voltage over a set time, and stops the switching unit. That is, even if the voltage of the battery falls below the rated voltage, if the voltage is restored within the set time, the switching unit does not stop and does not interrupt the transmission of power. In addition, the set time is set to about 2 to 10 minutes,
The capacity of the battery is preferably determined according to the set time.

If a conversion unit is interposed between the switching unit and the matching unit, the conversion unit can boost the power from the switching unit and send it to the matching unit. Can be used as is.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

The power selling device for the wind generator is a wind generator G
, A limiting unit 11, an opening / closing unit 12, a matching unit 14, and a battery B connected to the output side of the limiting unit 11 (FIG. 1).

The wind generator G is an AC generator, and is connected to a propeller G1. A limiting unit 11 is connected to the wind power generator G, and an output of the limiting unit 11 is branched and connected to a battery B and an opening / closing unit 12. The switching unit 12 is an inverter having an input voltage monitoring function, has a built-in timer element (not shown), and is provided with a timer element setter 12a. The output of the switching unit 12 is connected to the commercial power system PL via the conversion unit 13 and the matching unit 14. The matching unit 14 is, for example, a photovoltaic power generation inverter that sells power generated by a solar cell to the commercial power system PL, and converts the voltage, frequency, and voltage waveform of the sold power Pc to the required level of the commercial power system PL. Can be adapted to

The limiting unit 11 is configured by connecting a rectifying circuit 11a and a voltage adjusting circuit 11b in series (FIG. 2).
(A)). The conversion unit 13 is configured by connecting a step-up transformer 13a and a rectifying circuit 13b with a smoothing circuit in series (FIG. 1B).

Such a power selling device is, for example, a wind power generator G
When the generated power Pg changes over time, for example, as shown in FIG. 3, it operates as follows. 3, the horizontal axis represents time t, and the vertical axis Vp represents the input voltage of the opening / closing unit 12, that is, the voltage of the battery B.
Vp1 and Vp2 indicate the charging voltage and the rated voltage of the battery B, respectively.

When the generated power Pg of the wind power generator G is sufficiently large (time t <t1 in FIG. 3, hereinafter simply referred to as t <t1), the limiting unit 11 determines the maximum value of the output voltage of the battery B. Wind power generator G while limiting to charging voltage Vp1
, And outputs the generated power Pg as DC power Pd. Then, the battery B is charged by a part of the charging power P1 of the DC power Pd from the limiting unit 11, and the opening / closing unit 12 outputs the surplus power Po = Pd-P1 from the battery B.
As power Pa to the conversion unit 13. Further, conversion unit 13 boosts power Pa from switching unit 12 and outputs it to matching unit 14 as DC power Pb, so matching unit 14 sells DC power Pb as commercial power Pc to commercial power system PL. Can be charged. Note that the matching unit 14 is provided with
The voltage fluctuation, frequency fluctuation, and voltage waveform of c
L is matched to the required level.

When the power Pg generated by the wind power generator G decreases, the output voltage of the limiting unit 11 decreases, and the voltage Vp of the battery B also decreases (t ≧ t1). Then, when the voltage Vp ≦ Vp2 of the battery B is satisfied (t = t1a), the battery B is discharged with the charging power P1 = 0. In the limiting unit 11 at this time, even if the output voltage becomes lower than the voltage Vp of the battery B, the discharge power from the battery B does not flow backward by the rectifier circuit 11a.

On the other hand, the switching unit 12 at this time continuously sends the surplus power Po from the battery B, that is, the discharge power of the battery B as the power Pa (t ≧ t1a),
When it is detected that the voltage Vp has dropped to Vp ≦ Vp2 beyond the set time Ta set by the setting device 12a (t = t1
b) The transmission of the electric power Pa is stopped, and the selling of power to the commercial power system PL by the matching unit 14 is stopped. When the switching unit 12 stops sending the power Pa, the battery B stops discharging and enters a standby state (t ≧ t1b).

Next, when the generated power Pg of the wind power generator G recovers sufficiently large, the output voltage of the limiting unit 11 also recovers, and the charging of the battery B is restarted (t ≧ t2). Also, the battery B is charged, and the voltage Vp of the battery B = Vp = V
When the power is restored to p1 (t = t2a), the switching unit 12 automatically restarts and resumes the transmission of the electric power Pa, and transmits the electric power Pc to the commercial electric power system PL via the conversion unit 13 and the matching unit 14. You can sell electricity.

Further, even if the generated power Pg of the wind power generator G decreases and the voltage of the battery B drops to Vp ≦ Vp2 (t = t
3a), elapsed time Tb <Ta for recovery to voltage Vp = Vp1
If (t3a ≦ t ≦ t4), the opening / closing unit 12 does not interrupt the transmission of the electric power Pa and the matching unit 14
Can continuously sell the sold power Pc. In the same manner, the opening / closing unit 12 performs the operation (t> t) each time the voltage Vp ≦ Vp2 of the battery B exceeds the set time Ta.
5a), the transmission of the electric power Pa is stopped to stop the power selling, and if not, the power selling of the power selling power Pc by the matching unit 14 can be continued. The matching unit 14
It is preferable to have a built-in power control function and maintain the power sale power Pc at a constant level when the switching unit 12 is operating.

[0023]

[Other Embodiments] A plurality of wind power generators G, G,... Are connected in parallel via limiting units 11, 11,. Can be built.

Further, an output current limiting function may be added to the switching unit 12 or the conversion unit 13 in order to protect the battery B. The conversion unit 13 for boosting boosts the power Pa from the switching unit 12 and supplies it to the matching unit 14 as DC power Pb. Therefore, the conversion unit 13 may omit this by adjusting the voltage levels of the switching unit 12 and the matching unit 14. However, the matching unit 14 at this time
Has a built-in rectifier circuit on the input side.

[0025]

As described above, according to the present invention, the matching unit is provided by providing the limiting unit, the switching unit, and the matching unit connected to the wind power generator and the battery connected to the output side of the limiting unit. Can input power properly adjusted via the limiting unit, battery, and switching unit, match the voltage, frequency, and voltage waveform and sell the power to the commercial power system. There is an excellent effect that electricity can be sold smoothly in connection with the grid.

[Brief description of the drawings]

Fig. 1 Overall block system diagram

FIG. 2 is a block diagram of a main part.

FIG. 3 is an operation explanatory diagram.

FIG. 4 is a block diagram of a main part showing another embodiment.

[Explanation of symbols]

 G ... Wind power generator B ... Battery PL ... Commercial power system Vp ... Voltage Vp1 ... Charging voltage Vp2 ... Rated voltage Po ... Surplus power Pa ... Power Ta ... Setting time 11 ... Limiting unit 12 ... Opening / closing unit 13 ... Conversion unit 14 ... Matching unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H078 AA26 BB30 CC22 CC32 CC56 CC72 5G003 AA07 BA01 CA12 DA07 DA14 5G066 HB02 HB09 5H590 CA14 CA28 CD01 CD03 CE01 CE05 FC27 GA02 GA09 HA02 JA09

Claims (3)

[Claims] 1. A limiting unit connected to a wind power generator, a switching unit, a matching unit, and a battery connected to an output side of the limiting unit, wherein the limiting unit sets a maximum value of an output voltage to the battery. And the switching unit sends the surplus power from the battery to the matching unit side, and the matching unit matches the voltage, frequency, and voltage waveform to commercialize the power from the switching unit. A power selling device for a wind power generator, which sells power to a power system. 2. The switching unit according to claim 1, wherein the switching unit includes a timer element for detecting that the voltage of the battery has dropped below the rated voltage over a set time.
A power selling device for the wind generator as described. 3. The power selling device for a wind power generator according to claim 1, wherein a conversion unit for boosting is interposed between the switching unit and the matching unit.