JP2003111279A - Power leveling system - Google Patents

Abstract

(57) [Problem] To provide a power leveling system capable of steadily supplying a constant power with a gradual long-period fluctuation to a power system while saving power. A power generation facility using natural energy,
A power system 12 to which power is supplied from a power generation facility 11 and an auxiliary power supply facility 13 for adjusting fluctuations in power supplied to the power system 12 from the power generation facility 11 are provided. And a power leveling system 10 for leveling the supplied power. The auxiliary power supply facility 13 absorbs or supplies a power difference between power supplied from the power generation facility 11 to the power system 12 and target power which is constant power supplied to the power system 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power leveling system which can save power by utilizing natural energy and can stably supply power to a power system.

[0002]

2. Description of the Related Art In recent years, power generation equipment using natural energy such as wind power, tidal power, sunlight, and geothermal steam has attracted attention because of its small environmental load. Research and development of power generation equipment is in progress.

As a specific example, FIG. 6 shows the structure of a power generation facility using wind energy as natural energy.

As shown in FIG. 6, a power generation facility 1 is connected to a power system 2. The power generation facility 1 includes a wind turbine 3 that converts wind energy into rotational energy, a synchronous generator 4 that converts rotational energy from the wind turbine 3 into electrical energy, and the power generated by the synchronous generator 4 in an electric power system 2. The power converter 5 which converts into a frequency is provided.

In the power generation facility 1 having such a configuration,
Wind energy is converted into electric energy and supplied to the power system 2 in real time as it is.

[0006]

However, the power supply by natural energy such as wind energy is easily influenced by the weather, and the power that fluctuates slowly in a long cycle,
Alternatively, there is a problem that it is difficult to stably supply a certain amount of power to the power system.

For example, in a power generation facility using wind power, the power generation amount increases when the wind becomes strong, and the power generation amount decreases when the wind weakens, and the power supplied to the power system fluctuates in a short cycle.

Further, in a power generation facility using solar energy, the amount of power generation greatly depends on the sunshine duration or the weather, and when the power generation facility using natural energy is used,
There is a problem that a constant electric power, which is an electric power that gently changes in a long cycle, cannot be stably supplied.

The present invention has been made in order to solve such a problem, and achieves power saving, moderate long-cycle fluctuations in the power system, and power leveling capable of stably supplying a constant power. The purpose is to provide a system.

[0010]

As a result of various studies aimed at achieving the above object, the inventors of the present invention provided an auxiliary power supply facility for adjusting fluctuations in power supplied from a power generation facility using natural energy to a power system. , When the electric power supplied from the power generation equipment fluctuates, it is found that the electric power supply to the electric power system can be leveled by immediately canceling the changed electric power difference by supplying or absorbing the electric power from the auxiliary power supply equipment, The present invention has been completed.

In order to solve the above-mentioned problems, the power leveling system according to the present invention is provided with power generation equipment using natural energy and the power generated by this power generation equipment. Auxiliary power supply that absorbs or supplies the power difference between the power grid and the generated power and the target power supplied to the power grid, and adjusts the fluctuation of the generated power to reach the target power. It is equipped with equipment.

Further, in order to solve the above-mentioned problems, the power leveling system according to the present invention, as set forth in claim 2, supplies power generation equipment using natural energy and power generated by this power generation equipment. The power system to be absorbed, the power factor difference between the power factor of the generated power and the power factor of the target power supplied to the power system is absorbed or supplied, and the target power is adjusted by adjusting the fluctuation of the power factor of the generated power. The auxiliary power supply equipment for supplying the electric power to the electric power system is provided.

Further, in order to solve the above-mentioned problems,
As described in claim 3, the power leveling system according to the present invention is the power leveling system according to claim 1, wherein the generated power and the target power are either active power or reactive power, respectively. In addition, as described in claim 4, in the power leveling system according to any one of claims 1 to 3, the auxiliary power feeding facility includes a detector that detects generated power from the power generation facility, and an electric machine. A child winding is connected between the detector and the power grid and absorbs or supplies the power difference from the target power, and the field winding of this double-fed generator is connected to the field current. An exciting device that supplies a field current to the field winding of the doubly-fed generator from the power generation equipment or power system, and controls the exciting device based on the generated power detected by the detector. In the dual power generator In which a control device for controlling the absorption or supply the serial power difference.

According to the present invention, the amount of power generated by the power generation equipment due to natural energy, which is greatly influenced by the weather, is adjusted by the auxiliary power supply equipment, so that the electric power supplied to the power system is gradually changed to a long cycle and is constant. Power can be supplied stably.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A power leveling system according to the present invention will be described below with reference to FIGS.

In the present embodiment, a power leveling system using, for example, wind energy as natural energy will be described.

As shown in FIG. 1, a power leveling system 1
0 is a power generation facility 11 using wind energy and a power generation facility 1
1, which is connected to the power generation system 11 and is supplied with power generated by the power generation facility 11, and adjusts fluctuations in the power generated from the power generation facility 11 to vary power supply to the power system 12 at a constant or long cycle. And the auxiliary power supply device 13.

In the power generation facility 11 using wind energy, a synchronous generator 15 is connected to a wind turbine 14 for converting wind energy into rotational energy, and the synchronous energy is converted by the synchronous generator 15 into electric energy to obtain generated power. The generated electric power is supplied to the synchronous generator 15 to the electric power system 12
The power conversion device 16 for converting to the frequency is connected. Further, a detector 17 is provided between the power generation facility 11 and the power system 12 to detect generated power supplied from the power generation facility 11 to the power system 12.

On the other hand, the auxiliary power supply facility 13 is provided between the detector 17 and the power system 12. Auxiliary power supply facility 1
3 is composed of a doubly fed generator 18, an exciter 19 and a controller 20, and the armature winding of the doubly fed generator 18 is connected between the detector 17 and the power system 12 to achieve the target. It absorbs or supplies the power difference from the power. For this reason, the field winding of the doubly-fed generator 18 has an exciting device 1
9 is connected to the field winding of the doubly fed generator 18 from the power generation equipment 11 or the power system 12 to the exciter 19
A field current is supplied via the. A control device 20 is connected to the excitation device 19, and the generated power detected by the above-described detector 17 is input to the control device 20. That is, the control device 20 controls the absorption or supply of the electric power of the double-fed generator 18 based on the value of the electric power generated by the power generation equipment 11 detected by the detector 17.

The control device 20 is provided with at least a power reading means, a power difference calculating means, and a power adjustment commanding means. In this control device 20, the power reading means reads the detected power from the detector 17, the power difference calculating means obtains a power difference between the detected power and a preset target power, and the power adjustment is performed based on the power difference. The command means gives a power adjustment command to the exciter 19 to keep the power supply to the power system 12 constant.

In the following, as an example of the power detected by the detector 17 shown in FIG. 1, active power, reactive power, or both active power and reactive power are detected. Active power refers to the product of a current component and voltage that are in phase with the AC voltage, and reactive power refers to the product of a current component and a voltage that are 90 degrees out of phase with the AC voltage.

FIG. 2 is a graph showing an example of a change in active power with time, in which the horizontal axis represents time (t) and the vertical axis represents active power (P). The solid line A indicates the power generation facility 11
The time-dependent change of the generated active power P caused by the
Indicates the time change of the target active power P ′ supplied to the power system 12.

For example, the detector 17 detects the generated active power P at time t1, and the generated active power P is read into the control device 20. The target active power P ′ supplied to the power system 12 in advance is input to the control device 20, and the generated active power P and the target active power P at time t1 are input.
The active power difference ΔP (P−P ′) from ‘′ is calculated. When the active power difference ΔP is a positive value, that is, when the generated active power P from the power generation equipment 11 is higher than the target active power P ′, the control device 20 outputs the active power difference ΔP in order to cancel the active power difference ΔP. An active power adjustment command is given to the exciter 19, and the double power supply generator 18 is controlled to increase the rotation speed in order to absorb the active power difference ΔP. In this way, it is possible to supply the power system 12 with constant active power that is approximately the same as the target active power P '.

FIG. 3 is a graph showing the time variation of the reactive power, where the horizontal axis represents time (t) and the vertical axis represents active power (P). Further, the solid line C indicates the time variation of the reactive power generated by the power generation facility 11, and the broken line D indicates the time variation of the reactive power targeted by the power system 12.

For example, the detector 17 detects the generated reactive power Q at time t1, and the generated reactive power Q is read by the control device 20. A target reactive power Q ′, which is a target to be supplied to the power system 12, is input to the control device 20 in advance, and an active power difference ΔQ (Q−Q−Q) between the generated reactive power Q and the target reactive power Q ′ at time t1. Q ') is calculated. The control device 2 is configured to cancel this active power difference ΔQ.
A reactive power adjustment command is given to the exciter 19 from 0, and the doubly fed generator 18 is controlled to lower the terminal voltage in order to absorb the reactive power fluctuation.

In this way, the reactive power supplied to the power system 12 is kept constant.

FIG. 4 is a graph showing an example of changes over time in active power and reactive power. The horizontal axis represents time (t), and the vertical axis represents active power (P) and reactive power (Q). ing. Further, the solid line A shows the time change of the active power P generated from the power generation equipment 11, and the solid line C shows the time change of the reactive power Q generated from the power generation equipment 11. Further, a broken line B indicates a time change of the target active power P in the power system 12, and a broken line D
Shows the time variation of the reactive power Q targeted in the power system 12.

In the figure, for example, the generated active power P and the generated reactive power Q at time t1 are detected by the detector 17. The generated active power P and the generated reactive power Q at time t1 detected by the detector 17 are the control device 20.
Read in. The target target active power P ′ and the target target reactive power Q ′ are input to the control device 20 in advance, and the active power difference ΔP (P−P−
P ′) and the active power difference ΔQ (Q−Q ′) are calculated.
Since the controller 20 gives the exciter 19 a command to adjust the active power and the reactive power so as to cancel out the ΔP and ΔQ, the dual power supply generator 18 absorbs the active power fluctuation and the reactive power fluctuation. The rotational speed is controlled to increase with respect to the active power fluctuation, and the terminal voltage of the dual power supply generator 6 is decreased with respect to the reactive power fluctuation.

In this way, it is possible to supply a constant active power to the power system 12 and also keep the reactive power constant.

Next, a power leveling system for detecting the change in the power factor of the power generated from the power generation equipment 11 and leveling the power supplied to the power system 12 will be described with reference to FIG.

FIG. 5 is a graph showing an example of the change over time of the power factor. The horizontal axis represents time (t) and the vertical axis represents the power factor (p).
f) is shown. Further, the solid line E shows the time change of the power factor pf generated by the power generation facility 11, and the broken line F shows the time change of the target power factor pf of the power system 12.

In this figure, for example, the detector 17 shown in FIG. 1 detects the power factor pf at time t1. The power factor pf at time t1 detected by the detector 17 is read into the control device 20, and the power factor difference Δpf (pf−pf− between the target power factor pf ′ input in advance and the detected power factor pf.
pf ') is calculated. The controller 20 gives a power factor adjustment command to the exciter 19 so as to cancel the power factor difference Δpf, and the double power supply generator 18 absorbs or outputs the power factor variation, so that the double power supply generator 18 rotates. Control speed and terminal voltage.

According to this embodiment, the active power P supplied from the power generation facility 11 using natural energy to the power system 12 is P.
By detecting the electric power such as the reactive power Q and the power factor pf, calculating the electric power difference with the target electric power value based on the detected value, and keeping the electric power supplied to the electric power system 12 constant based on the electric power difference. Therefore, stable power supply can be achieved.

In this embodiment, wind energy is applied as natural energy, but solar energy, tidal energy, geothermal energy, etc. can also be applied.

Further, although the present system 10 is the power generation facility 11 using natural energy using the synchronous generator 15, an induction generator may be used in place of the synchronous generator 15, and when the induction generator is applied. Even if there is, the same effect can be exhibited.

[0036]

As described above, according to the electric power leveling system of the present invention, the electric power generated by the power generation equipment due to natural energy, which is affected by the weather, etc., is converted into a long period fluctuation or a constant electric power. The system can be stably supplied.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a power leveling system according to an embodiment of the present invention.

FIG. 2 is a graph showing a change over time in active power, which is interchange power.

FIG. 3 is a graph showing a time change of reactive power, which is interchange power.

FIG. 4 is a graph showing changes over time of active power and reactive power that are interchange power.

FIG. 5 is a graph showing a change over time in a power factor, which is interchange power.

FIG. 6 is a configuration diagram showing a conventional power generation facility using natural energy.

[Explanation of symbols]

10 Power leveling system 11 power generation equipment 12 power system 13 Auxiliary power supply equipment 14 windmill 15 Synchronous generator 16 Power converter 17 detector 18 doubly-fed generator 19 Exciter 20 Control device

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02P 9/00 H02P 9/00 FF term (reference) 3H078 AA02 AA26 BB01 CC22 CC73 5G066 HA15 HA19 HB02 JA07 JB02 5H590 AA30 BB09 CA01 CA14 CA29 CC01 CC08 CE01 CE05 EB02 EB04 EB05 FA01 FA05 FA08 GA02 GA06 GA07 GA08 GB05 HA02 HA06 HA07 HA08 JB06

Claims (4)

[Claims] 1. A power generation facility using natural energy, a power system to which power generated by this power generation facility is supplied, and a power difference between the generated power and target power supplied to the power system is absorbed or supplied, A power leveling system comprising: an auxiliary power supply facility that adjusts the fluctuation of the generated power to supply the power to the target power. 2. A power generation facility using natural energy, a power system to which power generated by the power generation facility is supplied, and a power factor of the power factor of the generated power and the power factor of target power supplied to the power system. A power leveling system comprising: an auxiliary power supply facility that absorbs or supplies a difference, adjusts a variation in a power factor of the generated power, and supplies the power to the power system so as to reach the target power. 3. The power leveling system according to claim 1, wherein the generated power and the target power are one or more types of active power and reactive power, respectively. 4. The power leveling system according to claim 1, wherein the auxiliary power feeding facility has a detector for detecting the power generated from the power generating facility, and the armature winding has a detector and power. A double-fed generator connected between the grids to absorb or supply the power difference from the target power, and a field current connected to the field winding of this double-fed generator to connect the power generation equipment or the power grid to the An exciting device that supplies a field current to a field winding of a double-fed generator, and the exciting device is controlled based on the generated power detected by the detector to control the exciting power of the double-fed generator. A power leveling system, comprising: a controller that controls absorption or supply of the power difference.