KR101168971B1 - Wind power generation system with power storage system - Google Patents

Abstract

The present invention is to reduce the energy loss due to the charge and discharge of the power storage system in the wind power generation system to mitigate the output fluctuations in which the power storage system is added, by reducing the amount of charge and discharge power of the power storage system.

To this end, the present invention has a means for determining the output possible range in the next control period from the maximum and minimum values of the output power of the wind power generator group and the power storage system in the past for a certain period of time. And a means for determining either or both of the amount of charge / discharge power of the power storage system and the power limit command of the wind power generator group such that the output power of the wind power generator group and the power storage system is contained within an output possible range. .

Description

Storage system Wind power generation system {WIND POWER GENERATION SYSTEM WITH POWER STORAGE SYSTEM}

The present invention relates to a wind power generation system including a power storage system and a windmill power generation system.

As a means for converting renewable energy present in the natural world into power energy, a group of wind power generators is used.

Since the energy source of the wind power generator group is wind energy that changes in time, the power generation of the wind power generator group also changes in time.

The power system maintains a balance of power supply and demand by adjusting the generated power of a large generator according to the size of electric power demand. For this reason, as described in Non-Patent Document 1, when the wind power generator group, which is a power source with large fluctuations, is linked to the power system in large quantities, there is a fear of lack of adjustment force and expansion of frequency fluctuation.

In order to prevent this, for example, as shown in Patent Literature 1, a power storage system is provided in a wind power generator group, and the power generation system charges and discharges power generated by the wind power generator group so that the power generation system flows out to the power system. Measures such as mitigating power fluctuations are necessary.

[Patent Document 1]

Japanese Patent Application Laid-Open No. 2007-124780

[Non-Patent Document 1]

"Results of Examination on the Possible Linkage of Wind Power Generation to the Northeast System" Tofuku Electric Power Co., Ltd. jp / oshirase / newene / 04

/pdf/h18_temp01.pdf>

As shown in Non-Patent Document 1, power fluctuations to be relaxed are divided into several regions by the fluctuation period. In particular, the fluctuation of about 20 minutes to about 20 minutes, called the intermediate period region, may lead to an increase in supply and demand imbalance due to lack of coordination, expansion of frequency variation, and the like. In order to avoid such adverse effects caused by power fluctuations in the intermediate periodic region, it is necessary to mitigate the power fluctuations in this frequency band. Specifically, it is desirable to restrain the output fluctuation range of the output power within a predetermined time period (for example, within 20 minutes) starting at an arbitrary time within a predetermined constant value (for example, 10% of the rated value of the wind power generation system). Do.

As means for alleviating the power fluctuations in the intermediate periodic region, for example, as shown in Patent Literature 1, a predetermined range is provided with respect to the average value of the generated power of the wind power generator group, and the battery is charged only when it deviates from this range. There is a means for performing discharge.

However, in the case of using the control method shown in Patent Literature 1, in order to alleviate the variation in the intermediate periodic region to be targeted, a simple output target value called the average value of the generated electric power is used, which contributes to the relaxation of the variation in the intermediate periodic region. Unnecessary charge and discharge of the battery may occur.

In the charge / discharge operation of the storage battery, loss in the storage battery always follows. For this reason, the charge / discharge of the battery which does not contribute to the fluctuation reduction increases the loss, and there is a fear that natural energy cannot be used effectively.

An object of the present invention is to suppress output fluctuations in a predetermined frequency range in a wind power generation system including a storage battery and to reduce power loss due to charging and discharging of the storage battery.

In the present invention, the output possible range in the next control period (control period) is determined from the maximum and minimum values of the output power of the wind power generator group and the power storage system in the past for a certain period. In the next control period, either or both of the charge / discharge power and the power limit command of the storage battery are determined so that the sum of the output powers of the wind power generator group and the power storage system falls within the output power possible range.

In the present invention, the wind power generation system has a means for receiving a power generation predicted value by weather forecast, and determines one or both of a charge rate command and a power limit command of the power storage system according to the predicted power generation value. .

Fluctuations in output power in the frequency range to be suppressed can be suppressed, and the loss due to charging and discharging of the battery can be reduced.

The wind power generation system of the present invention has an output possible range in the future of the next control period T2 from the maximum value and the minimum value of the sum of the output powers of the wind power generator group and the power storage system in the past of the predetermined period T1. Set (R). The electrical storage system performs the charging / discharging operation only when the generated electric power of the wind power generator group deviates from the output possible range R or when the charging rate of the storage battery deviates from the target range of the charging rate. The wind power generation system updates the output possible range for each control period T2.

Moreover, the wind power generation system of this invention is based on the minimum value of the output power of the wind power generator group and the electrical storage system in the past of the predetermined period T1, and the chargeable electric power of a storage battery in the future of the next predetermined time T3. The wind power generator group composed of one or more wind power generators, which calculates the power limit command, limits the generated power of the wind power generator group to less than or equal to the above limit command in the future of a predetermined time.

(Example 1)

A first embodiment of the present invention will be described with reference to FIGS. 1 to 17.

The structure of the wind power generation system which becomes the object of this invention is demonstrated using FIG. The wind power generation system of the present invention is composed of a wind power generator group (1), a power storage system (2), an upper control device (3), the associated transformer (4). The wind power generation system transmits generated power to the power system 5 in association with the power system 5. The power meter 6 which measures the generated electric power PW of the wind power generator group is provided in the connection point of the wind power generator group. In addition, the power meter 8 which measures the output power PS of a wind power plant is provided in the connection point of a wind power plant. In the wind power generation system, since a power meter 7 for measuring the charge / discharge power PB of the power storage system is provided at the connection point of the power storage system, the output power PS of the wind power plant is the power generation of the wind power generation system. You may calculate from PW and charging / discharging electric power PB of an electrical storage system. However, if the power meter 8 is installed and the output power PS is directly measured, the control performance of the system is higher than that obtained by calculating the output power PS by calculating from the generated power PW and the charge / discharge power PB. Improves. In addition, the relationship of the formula (1) is established in the output power PS of the wind power generation system, and PW and PB without considering the loss.

PS = PW + PB

The wind power generator group 1 constituting the wind power generation system will be described below. The wind turbine generator group 1 is comprised by one or more wind turbines 1-1-1, 1-1-2, ..., 1-1-n, and SCADA1-1. SCADA1-1 is responsible for collecting operation information such as the operation status of the wind power generation device group and the generated electric power. At the same time, the SCADA1-1 receives a limit command (PLC) for generating power of the wind turbine generator group 1 from the host controller, and the wind turbines 1-1 to 1,?,?,? , 1-1-n), each power limit command to each wind power generator (1-1-1,?,?,?, 1-1-n) so that the sum of the generated electric powers is equal to or less than the PLC Give it (PLC1, PLC2,?,?,?, PLCn).

The wind power generators 1-1-1,?,?,?, 1-1-n will be described with reference to FIGS. 2, 3, 4, and 5. 2 is a view showing one embodiment of a wind power generator. The wind power generator receives the wind by the blades 1-1-1-1 and converts the wind energy into rotational energy. Rotational energy is transmitted to generator 1-1-1-4. In Fig. 1, a DC excitation type synchronous generator 1-1-1-4 is shown as a generator 1-1-1-4. The stator of the DC excitation type synchronous generator 1-1-1-4 is connected to the system via an AC / DC converter 1-1-1-5 and a converter 1-1-1-6. In addition, the rotor of the DC excitation type synchronous generator (1-1-1-4) is also connected to the system via the excitation device (1-1-1-9), and the excitation device (1-1-1-9). ), The variable speed operation is realized by controlling the strength of the direct current excitation current. 3 is an example of a wind power generator using an alternating current excitation type synchronous generator (1-1-1a-4) as a generator. 4 is an example of the wind turbine generator which used the permanent magnet synchronous generator 1-1-1b-3 as a generator. The wind power generator groups of FIGS. 2, 3, and 4 all allow variable speed operation by adjusting the pitch angles of the power converter and the blade. Moreover, these wind power generators can limit the generated power to a predetermined value or less by combining the control of the pitch angle and the control of the power converter. 5 is an example of the wind power generator which used the induction generator 1-1-1c-4 as a generator. In the wind power generator shown in Fig. 5, the stator of the induction generator 1-1-1c-4 is directly connected to the power system without passing through the power converter. The wind power generator using the induction generator 1-1-1 c-4 can also limit the generated power to a predetermined value or less by controlling the pitch angle. The wind turbine generator group 1 is comprised by any one of the wind turbine generator shown in FIG. 2, FIG. 3, FIG. 4, FIG. 5, or a combination thereof.

Next, the power storage system 2 constituting the wind power generation system will be described. The electrical storage system 2 is comprised by one or more electrical storage devices 2-2-1, 2-2-2,?,?,?, 2-2-m. Each power storage device will be described with reference to FIG. 6. The electrical storage device 2-1-1 includes a plurality of secondary batteries 2-1-1-1, a converter 2-1-1-2, an associated transformer 2-1-1-3, Circuit breaker 2-1-1-4. The secondary battery is composed of any one of a lead acid battery, a sodium sulfur battery, a redox flow battery, a lithium ion battery, a nickel hydrogen battery, a lithium ion capacitor, or a combination thereof. 6 illustrates an example in which a secondary battery is used as the power storage device, but an electric double layer capacitor or a capacitor is used as a capacitor instead of a secondary battery, or a combination of a secondary battery and a capacitor, or another. Even if it is comprised by the combination of electrical storage elements, the effect of this invention is the same. In addition, even when a system capable of accumulating electric energy such as a flywheel as kinetic energy is used as the power storage device, the effect of the present invention is not lost. The power storage devices 2-2-1, 2-2-2,?,?,?, 2-2-m are each of the wind power generator group according to the charge / discharge electric power command from the host controller 3. The generated power can be charged or discharged. In addition, the power storage devices 2-2-1, 2-2-2,?,?,?, 2-2-m each measure the charge rate (SOC) of the storage battery, and the upper control device sets the value of the SOC. (3) to pass.

The wind power generation system in which the power storage system 2 is installed in the wind power generator group 1 can alleviate fluctuations in the generated power of the wind power generator group with large fluctuations due to the charge / discharge operation of the power storage system. It can be called a wind power generation system that is difficult to reach.

On the other hand, the charge / discharge operation of the battery always involves a loss due to a loss caused by a power converter, a loss inside the battery, or the like. In order to make the best use of natural energy, it is desirable to reduce the amount of power charged and discharged by the storage battery as little as possible.

Therefore, in order to make both the fluctuation of electric power fluctuation and the effective use of natural energy compatible, it is necessary to reduce unnecessary charge / discharge operations which do not contribute to the fluctuation of the fluctuation as much as possible.

The fluctuations in generated power generated by the wind power generator group exist over a wide frequency range. In particular, fluctuations of about 20 minutes or so, called the intermediate period region, may lead to an increase in supply and demand imbalance due to lack of adjustment of the power system and an increase in frequency fluctuation. In order to avoid such adverse effects caused by power fluctuations in the intermediate periodic region, it is necessary to mitigate the power fluctuations in this frequency band. Specifically, the output fluctuation of the generated electric power within a certain period (for example, within 20 minutes) starting at an arbitrary time always falls within a certain value (for example, 10% or less of the wind power generation system rating), In other words, it is effective to fall within the allowable fluctuation range of the output power.

If the power fluctuation of the wind power generation system is about 10% or less of the rated value, it is possible to reduce the influence on the system even when a large number of wind power generator groups are linked. In the following, a description will be given of a control system in which the power fluctuation of 20 minutes starting at an arbitrary time falls within 10% or less of the wind power generation system rating.

In order to suppress the power fluctuation for 20 minutes to 10% or less of the wind power generation system rating and reduce the amount of charge / discharge power of the storage battery as much as possible, the control shown in FIG. 7 may be implemented. That is, the output of PS in the next control period (one minute in FIG. 7) from the output fluctuation range of the output power PS of the wind power generation system from a predetermined period (19 minutes in FIG. 7) to the present time t. Set the possible range (R). Specifically, the upper limit of the range R is set by adding 10% to the minimum value PSmin of the PS in the past of the predetermined period (19 minutes in FIG. 7). The value obtained by subtracting 10% from the maximum value PSmax is set to the lower limit of the range R.

In the next control period (one minute in FIG. 7), the charge / discharge power PB of the electrical storage system is adjusted so that the PS falls within this range. The power storage system 2 charges and discharges when the power generation of the wind power generator group 1 is out of the above range, or when the SOC of the power storage system 2 is outside the charge rate target range. It is only. By performing charge / discharge control of the electrical storage system 2 in this way, the power fluctuation in 20 minutes of the output power PS of a wind power generation system is always suppressed to 10% or less, and also the amount of charge / discharge power of a storage battery is reduced. It becomes possible.

In addition, as another means of mitigating power fluctuations in the wind power generation system, the power limitation of the wind turbine group may be used. That is, in the period in which the wind speed is rapidly increasing, it is possible to limit and mitigate an increase in the generated power PW of the wind power generator group 1 by using the power limit function of the wind power generator. However, the power limit function is realized by retreating the wind energy that was originally available by adjusting the pitch angle. For this reason, in order to effectively use natural energy, it is preferable not to use a power limit function as much as possible.

In this way, it is preferable to use the charging of the electrical storage system 2 as much as possible as a means of suppressing the surge of the output power PS of the wind power generation system. This is because some of the electric power charged in the electrical storage system 2 is lost due to loss, but can be effectively utilized by discharging. Therefore, in order to effectively use natural energy, it is necessary to store power as much as possible by the charging function of the storage battery and to suppress only the power that could not be stored by the power limiting function.

In the following, a wind power generation system that realizes a control method that minimizes the amount of charge / discharge power of a storage battery and a charging method of the power storage system 2 to realize a control method that does not use the power limit function as much as possible will be described in detail. Explain.

8 is a diagram showing the control configuration of the upper level control device 3 constituting the wind power generation system of the present invention. The upper control device 3 is configured to generate power PW of the wind power generator group, output power PS of the wind power generation system (output power PS), and charge the power generation power PW of the wind power generation group and the power storage system. In the case of obtaining from the discharge power PB, the charge / discharge power instruction PBC1, of the battery device is obtained from the charge / discharge power PB of the power storage system] and the charge rate SOC1, SOC2,?,?,?, SOCm of the power storage device. PBC2,?,?,?, PBCm) and the power limit command (PLC) of the wind power generator group 1 are determined. The host controller 3 calculates the charging rate target value SOCT of the electrical storage system 2 in the SOC target value calculation unit 3-1. In addition, when the upper level control apparatus 3 does not install the electric power meter 8, it calculates the output power PS of a wind power generation system by adding PW and PB. 8 illustrates an example of calculating the output power PS of the wind power generation system by adding PW and PB. When the output power PS detected by installing the power meter 8 is used, the detected value of the output power PS from the power meter 8 is directly input to the maximum value / minimum value calculation part 3-2 (shown in FIG. skip). The maximum value / minimum value calculation part 3-2 is provided with the output power recording memory (not shown) which records the output power PS which is the sum of the generated power PW and the charge / discharge power PB. Here, the output power PS that is the sum of the generated power PW and the charge / discharge power PB includes the output power PS detected by the power meter 8. In addition, in the case of adding PW and PB detected by the power meter 6 and the power meter 7, respectively, in consideration of the loss, the output power PS detected by the power meter 8 may not match. Process as power PS. The host controller 3 reads the information of the output power from the output power recording memory in the maximum value / minimum value calculation section 3-2, and calculates the maximum value PSMax and the minimum value (PS) in the past 19 minutes. PSMin). In addition, the host controller 3 calculates the charge / discharge power command PBC of the power storage system by the charge / discharge power command calculation unit 3-3. The charge / discharge electric power command PBC is stored in each of the electric storage devices 2-1-1, 2-1-2,?,?,?, 2-1- in the charge / discharge electric power command distribution unit 3-5. m) is distributed to the charge / discharge electric power instructions (PBC1, PBC2,?,?,?, PBCm) and transmitted to one power storage device. In addition, the relationship shown in equation (2) is established in the charge / discharge power command PBC of the power storage system and the charge / discharge power command PBC1, PBC2,?,?,?, PBCm for each power storage device.

PBC = PBC1 + PBC2 + PBC3 +... … + PBCm

The host controller 3 calculates the power limit command PLC of the wind turbine generator group in the power limit command calculation unit 3-4.

Next, the operation of the SOC target value calculator 3-1 will be described in detail with reference to FIG. The SOC target value calculation unit 3-1 calculates the charging rate target value SOCT of the electrical storage system 2 from the power generation power PW of the wind power generator group 1. As the charging rate target value of the electrical storage system 2, as shown in FIG. 9, the value corresponding to PW and SOCT is kept inside 1 to 1, and SOCT is determined by referring to this internal value. In addition, the SOCT determination method does not necessarily depend on PW, as shown in FIG. 9, and does not depend on PW, for example. Even if it is a fixed value, the effect of this invention is not lost.

Next, the operation of the maximum value / minimum value calculating section 3-2 will be described in detail with reference to FIG. The maximum value / minimum value calculation part 3-2 stores the PS of the past for a predetermined period at the present time in the internal memory. The maximum value / minimum value calculation unit 3-2 calculates the maximum value PSMax and PSMin of the PS between the present time and the past for a certain period.

Next, the operation of the charge / discharge power command calculation unit 3-3 will be described in detail with reference to FIG. The charge / discharge power command calculation unit 3-3 generates the intermediate value PBSOC of the charge / discharge power command for SOC management in the SOC management control unit 3-3-1. The charge / discharge power command calculation unit 3-3 generates the value PBC1 obtained by adding PW to the PBSOC, and applies the limiter 3-3-2 and the limiter 3-3-3 to charge and discharge the battery. Find the median value PBC3 of the power command. The charge / discharge power command calculation unit 3-3 calculates the charge / discharge power command PBC by subtracting the PW from the intermediate value PBC3. The first limiter 3-3-2 sets the upper limit to the value obtained by adding 10% of the wind power generation system rating to the PSMin and the lower limit to the value obtained by subtracting 10% of the wind power generation system rating from the PSMax. By the effect of this limiter 3-3-2, the fluctuation of the output power PS of the wind power generation system can be suppressed to 10% or less in an arbitrary cross section for 20 minutes. In addition, when the generated electric power PW of the wind power generator group is within the limiter range, the power storage system does not charge or discharge, and unnecessary charge and discharge can be avoided. The second limiter 3-3-3 sets the upper limit to 100% of the wind power system rating and the lower limit to 0%. By the effect of the limiter 3-3-3, the output power PS of the wind power generation system exceeds the rating of the wind power generation system, or the PS becomes negative and the wind power generation system becomes charged. You can prevent it.

Next, the operation of the SOC management control unit 3-3-1 will be described with reference to FIG. 12. The SOC management control unit 3-3-1 charges and discharges the charging rate of each power storage device 2-1-1, 2-1-2,?,?,?, 2-1-m close to the target charge rate. Write power command. Specifically, as shown in the SOC management control unit 3-3-1-1, the measured value SOC1 of the charge rate of the power storage device is compared with the target value SOCT of the charge rate. At this time, when SOC1 is larger than SOCT + dead band (for example, 2%), a discharge power command of 10% of the wind power generation system rating is prepared as the charge / discharge power command (PBSOCT1). Similarly, if SOC1 is smaller than SOCT − dead band (for example, 2%), a charge power command of 10% of the wind power generation system rating is created as the charge / discharge power command (PBSOCT1). If SOC1 is within the SOCT dead band, 0 [kW] is written as PBSOCT1. The S0C management control unit 3-3-1 performs this operation on all power storage devices 2-1-1, 2-1-2,?,?,?, 2-1-m, The charge / discharge power command PBCSOC of the electrical storage system is prepared by adding the discharge power commands PBSOCT1, PBSOCT2,?,?,?, And PBSOCTm. By performing such a control operation, unnecessary charge / discharge of the storage battery can be prevented.

Next, the operation of the power limit command calculating section 3-4 will be described with reference to FIG. The power limit command calculation unit 3-4 calculates the power value PBChargeMax that the power storage system can charge from the charge rate SOC of the power storage system 2 in the chargeable power calculation unit 3-4-1. The power limit command calculation unit 3-4 is configured to calculate the minimum value PSMin of the output power of the wind power generation system, PBChargeMax, and P2 (for example, 10% of the wind power generation system. The value obtained by adding.) Is regarded as the power limit command (PLC) of the wind turbine generator group.

By determining the PLC in this way, even when the power generation power PS of the wind turbine generator group 1 increases, the storage battery is charged as much as possible, and only the power that cannot be charged is suppressed by the power limit function. At the same time, the fluctuation in the output power PS of the wind power generation system can be suppressed to 10% or less in the cross section for any 20 minutes.

Next, the operation of the chargeable electric power calculating unit 3-4-1 will be described with reference to FIG. 14. The chargeable electric power calculating unit 3-4-1 stores the power storage system from the chargeable electric power values of the respective power storage devices 2-1-1, 2-1-2,?,?,?, 2-1-m. The chargeable power PBChargeMax of (2) is calculated. Specifically, in the chargeable power calculation unit 3-4-1-1, the chargeable power of the power storage device 2-1-1 is obtained from the charge rate measurement value SOC1 of the power storage device 2-1-1. Calculate (PBChargeMax1). Power storage devices such as secondary batteries (2-1-1, 2-1-2,?,?,?, 2-1-m) change the range in which charge and discharge are possible by SOC. The chargeable electric power calculating unit 3-4-1-1 is capable of charging and discharging according to the characteristics of the power storage devices 2-1-1, 2-1-2,?,?,?, 2-1-m. Is stored in the memory, and the corresponding chargeable power value PBChargeMax1 is read from the memory in accordance with the measured value SOC of the rechargeable battery. The chargeable electric power calculating unit 3-4-1 performs this calculation on all power storage devices 2-1-1, 2-1-2,?,?,?, 2-1-m, The chargeable power PBChargeMax of the electrical storage system 2 is calculated by adding the chargeable powers PBChargeMax1, PBChargeMax2,?,?,?, And PBChargeMaxm. In Fig. 14, the PBChargeMax is determined only by the charging rate (SOC) of the power storage device. However, the PBChargeMax may be corrected in consideration of the temperature of the power storage device, the number of years of use of the power storage device, the total charge / discharge power amount, and the like.

Next, an operation example of the wind power generation system of the present invention will be described below. 15 is a result obtained by simulation of the fluctuation mitigation operation by the power storage system 2 of the present invention. The graph in the upper part of FIG. 15 has shown the generated power PW of the wind power generator group 1, the output power PS of the wind power generation system, and the output possible range R of PS. In FIG. 15, the output allowable range R is set so that the variation in 20 minutes is 10% or less of the wind power generation system, and if it is within this range, the wind power generation system may be operated in 20 minutes starting at an arbitrary time. The fluctuation is kept below 10%. The output power PS of the wind power generation system shown in FIG. 15 is always in this output possible range R, and implement | achieves within 10% of output fluctuations for 20 minutes. The lower graph of FIG. 15 shows the charge / discharge power PB of the power storage system 2 and the charge rate SOC of the power storage system 2. In the simulation of FIG. 15, the charge rate target value range of the power storage system 2 is set to (50% ± 2% = 48% to 52%). At a time before the time 3 [hour] in FIG. 15, the power storage system 2 does not charge or discharge because the fluctuation range for 20 minutes is 10% or less and the SOC is within the charge rate target range. Therefore, the subject of this invention which does not perform charging / discharging of a storage battery as much as possible can be achieved. In addition, around 4.5 hours, although the generated electric power PW of the wind power generator group 1 exists in the output possible range R, the storage battery performs charging operation. This is an operation for entering the charge rate SOC of the power storage system 2 within the charge rate target range, and the SOC can be brought into the charge rate target range by this charge operation. In addition, even during the charging operation for SOC management, the PS operates so that the fluctuation range in 20 minutes is within 10%.

Next, with reference to FIG. 16, the operation example of the wind power generation system by the power limit control of this invention is demonstrated. Fig. 16 shows results obtained by simulation of fluctuation mitigation operation by the power limit control of the present invention. The upper graph of FIG. 16 shows the generation power PW of the wind power generator group, the output power PS of the wind power generation system, the power limit command PLC of the wind power generator group 1, and the power limitation. The power generation power PW0 of the wind power generator group 1 is shown. The generated electric power of the wind power generator group 1 starts to rise around time 1.10 [hour], and immediately after the rise, the fluctuation range for 20 minutes is kept within 10% by the charging operation of the power storage system. Around time 2.0 [hour], the charging rate of the electrical storage system 2 reaches 100 [%]. Since the power storage system 2 cannot perform the charging operation at a charge rate of 100 [%] or more, the power generation system PW is suppressed by the power limit function of the wind power generator group 1 at time 2.0 [hour]. The object of the present invention is to effectively use natural energy without using the power limiting function as much as possible by preferentially performing the charging operation of the power storage system 2 by the power limiting function depending on the SOC of the power storage system 2. Are satisfied.

Next, the effect of this invention is demonstrated using FIG. 17 shows the effect of the present invention applied to an existing wind power generation system by simulation. Specifically, the results obtained by numerical simulations of the operation when the power storage system is installed on the basis of about one year of power generation output data of an existing wind power generation system without a power storage system. In the simulation, the MW capacity of the power storage system is 90% of the rated capacity of the wind power generation system, and the MWh capacity is infinite. That is, the electrical storage system can always discharge 90% and charge 90%. In the simulation, for comparison purposes, in addition to the battery control of the present invention, the output power PS of the known wind power generation system follows the primary delay of the power generation power PW of the wind power generator group 1. The evaluation was also performed for the control method for charging and discharging, and the control for charging and discharging the storage battery only when the primary delay tracking + fixed width of the PW was deviated.

Fig. 17 summarizes the simulation results and shows the deviation frequency, the total charge power amount of the storage battery, the total discharge power amount, and the loss due to the charge / discharge of the battery. In addition, the deviation frequency is the occurrence frequency of the event in which the output power PS of the wind power generation system fluctuates more than 10% in 20 minutes starting at an arbitrary time. The loss is a value obtained by assuming that the charge and discharge efficiency of the storage battery is constant at 70% from the total discharge power amount of the storage battery. In the first delay tracking and the first delay tracking + fixed width control, there is a case where the time constant of the first delay is 180 minutes or more and the deviation rate is 0.0 [%]. Among cases of achieving these deviation ratios of 0.0 [%], even when the charging and discharging loss was the least, the loss occurred at 5.8 [%]. On the other hand, when the present invention is implemented, the deviation frequency is 0.0 [%], and the loss is very small, 2.1 [%]. Therefore, it can be confirmed that the problem of reducing the amount of charge / discharge power of the power storage system and the loss caused by the charge / discharge of the power storage system, which has been a problem of the present invention, can be confirmed.

In addition, the structure of the wind power generation system of this invention is not limited to FIG. 1, The effect of this invention is the same, even if the higher-level control apparatus 3 also functions as the control apparatus of an electrical storage system. Similarly, even if the upper control device 3 also functions as the SCADA1-1 of the wind turbine generator group 1, the effect of the present invention is not lost. In addition, the wind turbine generator group does not have SCADA1-1, and the higher-level controller 3 is connected to each wind turbine generator 1-1-1, 1-1-2, ..., 1-1-n. Even in the form of direct power limit instruction, the effect of the present invention is not lost.

In addition, in the wind power generator of the present invention, not all of the windmills need to have a power limiting function, and instead of the power limiting function, the wind turbines as a whole of the wind power generator group are converted by converting the operation and stop states of the windmills. The present invention can be implemented by adopting a configuration having a function of limiting the generated power to a predetermined value or less.

In addition, in the present embodiment, the power fluctuation of the fluctuation mitigation target is limited to a frequency of several minutes to about 20 minutes. However, since the frequency band to be fluctuated is different for each power system, the control constant is changed according to the power system. The effect is similarly feasible.

In the present embodiment, the power storage system 2 does not charge or discharge while the generated power PW is within the output possible range R and the charge rate SOC is within the charge rate target range. While the power storage system does not perform charging and discharging, the auxiliary machine power supply of the converter 2-1-1-2 constituting the power storage system 2 may be stopped. Specifically, the air cooling fan constituting the converter 2-1-1-2 is stopped, the supply of control power is stopped, and the switching operation of the semiconductor element is stopped. By the stop operation of the auxiliary machine power supply, it is possible to reduce the loss that the power storage system 2 normally generates, and to use the natural energy more effectively.

As described above, by using the present invention, it is possible to reduce the loss due to charging and discharging of the power storage system 2 while suppressing the output fluctuation of the wind power generation system. Moreover, by using this invention, the loss by electric power limitation can be reduced. Moreover, since the charge / discharge electric power amount of the electrical storage system 2 can be reduced by the effect of this invention, it is possible to reduce the storage battery capacity required for the electrical storage system 2, and the electrical storage system which is an aspect of this invention is added. Facilitate the introduction of a wind power generation system. Moreover, since the charge / discharge power amount of the electrical storage system 2 can be reduced by the effect of this invention, the life of an electrical storage device can be extended longer than before. Therefore, natural energy can be utilized more effectively than the prior art by using this invention.

(Example 2)

A second embodiment of the present invention will be described with reference to FIGS. 18, 19 and 20.

The difference from the first embodiment of the present invention is that the wind power generation system has a predetermined output power upper limit command (PMaxC), so that the output value of the wind power generation system is always lower than or equal to the output power upper limit command (PMaxC). It operates by combining the power limit of the battery and the charging of the power storage system. The part different from the structure of Example 1 of this invention is demonstrated using FIG. 18, FIG.

18, the charge / discharge battery command calculating section 3a-3 in the present embodiment will be described. The charge / discharge command unit 3a-3 of the present embodiment differs from the charge / discharge command unit 3-3 of the first embodiment by setting the upper limit value of the limiter 3a-3-3 to the rating of the wind power generation system. Rather, the point is set to the output power upper limit command (PMaxC) (70% of the wind power system rating in this embodiment), which is a value below the wind power system rating. Since other parts of the charge / discharge battery command calculation unit 3a-3 of the present embodiment are the same as the charge / discharge battery command calculation unit 3-3 of the first embodiment, description thereof is omitted.

19, the power limit command calculating section 3a-4 in the present embodiment will be described. The power limit command calculating section 3a-4 of the present embodiment differs from the power limit command calculating section 3-4 of the first embodiment in that the minimum value selecting calculating section 3a-4-2 is newly added. The minimum value selection calculating section 3a-4-2 compares (PSMin + 10%) and PMaxC and selects the smaller one. Since other parts of the power limit command calculating section 3a-4 of the present embodiment are the same as those of the power limit command calculating section 3-4 of the first embodiment, description thereof is omitted.

18 and 19, the output power value of the wind power generation system of Example 2 is always suppressed to be below PMaxC.

The control operation and effects in the configuration of the second embodiment of the present invention will be described with reference to FIG. In the wind power generation device group which installs a power storage system, the ratio of the power storage system 2 cost to the cost of the whole wind power generation system is generally high. There is a concern that the cost of the battery system 2 may hinder the introduction of the power storage system parallel type wind power generator group.

In order to facilitate the introduction of the power storage system side wind power generator group, it is desirable to reduce the capacity of the power storage system 2 as much as possible. However, if the capacity of the electrical storage system 2 is reduced, the variation in the output power PS of the wind power generation system tends to be expanded. For example, FIG. 20 shows an operation example when the rated charge / discharge power value (maximum charge / discharge power value) of the power storage system is set to 60% of the wind power generation system rated value. In addition, the rated charge / discharge power value of the power storage system is generally equal to the converter capacity of the power storage system.

20 (a) and 20 (b), it is assumed that the wind speed in the vicinity of the wind power generation system gradually increases, and then decreases rapidly in time. FIG. 20A is a diagram showing time variation of power and charge rate (SOC) when power is controlled by the method described in Example 1. FIG. The generated power PW of the wind power generator group 1 gradually increases with the wind speed, and then decreases rapidly in time. When the power generation power PW is increased, the rate of change is less than or equal to a certain value by the charging operation of the electrical storage system 2 and the power limiting operation of the wind power generator group 1 (in this embodiment, the variation of the PS for 20 minutes is reduced. 10% or less). However, in the sudden reduction of the generated electric power PW, it is necessary to mitigate the fluctuation of the PS by the discharge operation of the power storage system 2, but since the rated capacity of the power storage system is only 60% of the wind power generation system, The rate of change cannot be suppressed below a certain value, and a big change occurs.

FIG. 20B is a diagram showing time variation of power and charge rate SOC when the control operation of the present embodiment is performed. In this embodiment, the output power upper limit command PMaxC of the wind power generation system is set to the rated power value (60%) + 10% of the power storage system. The output power PS of the wind power generation system is always suppressed below PMaxC by the power limiting operation of the wind power generator group 1 and the charging operation of the power storage system 2. For this reason, even when the wind speed decreases rapidly and the power generation power PW of the wind turbine generator group 1 decreases rapidly, the maximum fluctuation range is 10% (= PMaxC-power storage) due to the discharge operation of the power storage system 2. Can be suppressed below the system rated value. Thereby, the fluctuation of the output power of the wind power generation system can be suppressed to a fixed value or less (in this embodiment, the fluctuation range of the PS for 20 minutes is 10% or less).

As shown in the present embodiment, the output power PS of the wind power generation system is always set to a predetermined value or less by the power limiting function of the wind power generator group 1 and the charging function of the power storage system 2, thereby saving the power storage system. Even when the rated capacity of (2) is smaller than the rated capacity of the wind turbine generator group 1, it is possible to suppress the variation rate below a fixed value. By this effect, the capacity of the electrical storage system 2 can be reduced, the introduction of the battery-powered wind power generation system can be facilitated, and natural energy can be effectively utilized.

(Example 3)

A third embodiment of the present invention will be described with reference to Figs. 21-27.

The difference between the first embodiment and the second embodiment of the present embodiment is that the wind power generation system is based on the power limitation control of the wind power generator group 1 and the charge / discharge control of the power storage system 2 based on the weather forecast. This point is to use the generated power prediction value of the wind power generator group (1).

The structure of the wind power generation system of this invention is demonstrated using FIG. Among the components of the wind power generation system of the present embodiment shown in FIG. 21, the same components as those in FIG. 1 are the same components, and thus description thereof is omitted. In the wind power generation system of the present embodiment, the host controller 3b receives the power generation power prediction value PP of the wind power generation system from the power generation power prediction company 9 via the signal line 8. The generation power prediction company 9 predicts the generation power PP in the future from the past weather data, the terrain data, the current operation situation of the wind power generation system, and the past operation data of the wind power generation system.

The configuration of the host controller 3b will be described with reference to FIGS. 22, 23, 24, and 25. Among the configurations of the high-level control device 3b of the present embodiment, the difference from the high-level control device 3 (FIG. 8) of the first embodiment is the power storage system SOC target value calculation unit 3b-1 and the power storage system charge / discharge power command. Only the calculating part 3b-3 and the wind power generator group electric power limit command calculating part 3b-4. Since other components among the components of the host controller 3b are the same as those in the first embodiment, description thereof is omitted.

The operation of the SOC target value calculator 3b-1 of the present embodiment will be described with reference to FIG. In FIG. 22, since operation of 3b-1-1 performs the same operation as SOC target value calculating part 3-1 of Example 1, description is abbreviate | omitted. The SOC target value calculation unit 3b-1 finds an event in which the generated power prediction value PP greatly fluctuates in the near future in the internal power prediction value variation rate calculation unit 3b-1-2. When the power generation power prediction value PP rapidly increases in the near future, the SOC target value is set small. In addition, when the generation power prediction value PP decreases rapidly in the near future, the SOC target value is set large. In the near future, if there is no sudden change in the predicted power generation value PP, the SOC target value is determined from the generated power PW of the wind power generator group as in the first embodiment. In this embodiment, in the wind power generation system, the means for changing the target value SOCT of the SOC based on the generation power prediction value PP in accordance with the operation of the SOC target value calculation unit 3b-1 of the electrical storage system 2 as described above. Has

Next, the operation of the charge / discharge power command calculation unit 3b-3 of the present embodiment will be described with reference to FIG. Of the charge / discharge power command calculation units 3b-3 shown in FIG. 23, the components having the same numbers as the charge / discharge power command calculation units 3-3 shown in FIG. 11 perform the same operations as those in the first embodiment. Omit. The charge / discharge power command calculation unit 3b-3 of the present embodiment sets the upper limit value to the output power upper limit command PMaxC, not the wind power generation system rated value, in the limiter 3b-3-3. The PMaxC is calculated from the wind power generator group output power predicted value PP by the power generation system upper limit calculation unit 3b-3-4.

Next, the operation of the power limit command calculating section 3b-4 of the present embodiment will be described with reference to FIG. Of the wind power generator group power limit command calculation unit 3b-4 shown in FIG. 24, the same components as those of the wind power generator group power limit command calculation unit 3-4 shown in FIG. 13 operate in the same manner as in the first embodiment. Since the description is omitted. The wind power generator group power limit command calculating section 3b-4 of the present embodiment compares (PSMin + 10%) and PMaxC in the minimum value selecting calculating section 3b-4-2 and selects the smaller one. PMaxC is calculated from the wind power generator group output power predicted value PP in the output power upper limit command calculating unit 3b-4-3.

The operation of the power generation system upper limit calculation unit 3b-3-4 and the power generation system upper limit calculation unit 3b-4-3 will be described with reference to FIG. 25. The generation system upper limit calculation unit 3b-3-4 (3 b-4-3) finds an event in which the generation power prediction value PP decreases rapidly in the future from the generation power prediction value PP, and accordingly, Write upper limit output command (PMaxC). Specifically, PMaxC is slowly decreased until the time when PP decreases sharply. In addition, the reduction rate of PMaxC is reduced at a constant rate of, for example, 10 [%] / 20 [min], and at a time when PP decreases rapidly, so that PMaxC becomes the rated capacity of the electrical storage system 2. Set PMaxC. In the time zone where there is no sudden change of PP, PMaxC is set to the wind power generation system rated value.

In the present embodiment, the wind power generator group is operated by the operation of the charge / discharge power command calculation unit 3b-3, the power limit command calculation unit 3b-4, and the upper limit calculation unit 3b-3-4. Means for changing the output power upper limit command (PMaxC) by the windmill generation power prediction value (PP) based on the weather forecast, the output power of the wind power generation system, the power limit function of the wind power generator group 1, and power storage Means for suppressing the PMaxC or less by the charging operation of the system (2).

Examples of the control operation and effects in the present embodiment of the present invention will be described with reference to FIGS. 26 and 27. 26 (a) and 26 (b) show an example of operation in which the wind speed in the vicinity of the wind power generation system is rapidly increased, and FIGS. 27 (a) and 27 (b) show the phenomenon in which the wind speed is rapidly reduced. .

26 (a) and 26 (b), the operation when the wind speed rapidly increases will be described. In this embodiment, a case where a lead battery, a sodium sulfur battery, or a lithium battery which is a secondary battery is used as the power storage system 2 is assumed. In general, the secondary battery has a property in which the magnitude of the chargeable electric power decreases when the SOC is high. For this reason, when the power storage system 2 performs the charging operation to alleviate the fluctuation, it is preferable to set the amplitude value of the chargeable power to a large value by controlling the charge rate SOC of the power storage system 2 to be low. .

Fig. 26A is an example of operation when the control shown in the first embodiment of the present invention is performed. In FIG. 26A, the wind power generation system changes the SOC target value according to the generation power PW of the wind power generator group. For this reason, as the power generation power PW increases, the charging rate SOC also increases. When the charge rate SOC is a high value, the amplitude of the chargeable electric power becomes small, so that the fluctuation rate cannot be alleviated only by the charging operation of the power storage system 2. In order to suppress the rate of change of the wind power generation system output power (PS) below a certain value, the wind power generation system suppresses the power that cannot be charged by the power storage system (2) by the power limit function of the wind power generator group (1). do. For this reason, natural energy loss occurs due to power limitation.

Fig. 26B is an example of operation when the control shown in the third embodiment of the present invention is performed. FIG. 26 (b) sets the target value SOCT of the SOC to 0 [%] before the generation power PW suddenly increases in accordance with the operation of the SOC target value calculation unit 3b-1 shown in FIG. 22. . Due to this effect, the SOC decreases to near 0 [%] immediately before the PW suddenly increases, and it is possible to maintain the SOC at a relatively low value even in a period after the PW suddenly increases. By keeping the SOC low, the amplitude of the chargeable power of the power storage system increases, so that the rate of change of the PS can be suppressed to a predetermined value or less by only the charging operation of the power storage system 2 without limiting the power. The electric power charged in the electrical storage system 2 can discharge most of the electricity to the system, and the natural energy can be effectively utilized as compared with the case of Fig. 26A which suppresses the fluctuation by the electric power limitation.

Next, an operation in the case where the wind speed rapidly decreases will be described with reference to FIG. 27. In FIG. 27 (a) and FIG. 27 (b), the case where the converter rating of the electrical storage system 2 is 50 [%] of the wind power generator group 1 is assumed. 27A is an example of operation when the control shown in the first embodiment of the present invention is performed. As the wind speed decreases, the generated power PW of the wind power generator group 1 also drops sharply. When PW suddenly decreases, the wind power generation system discharges from the power storage system 2 in order to alleviate variations in the output power PS. However, since the rated capacity of the power storage system 2 is only 50%, the wind power generation system is alleviated. We cannot do it and big fluctuation occurs.

FIG. 27B is an example of the operation when the control shown in the third embodiment of the present invention is performed. In FIG. 27B, the wind power generation system changes the SOC target value in accordance with the generation power prediction value PP based on the weather forecast as shown in FIG. 22, and simultaneously changes the SOC target value in accordance with PP as shown in FIG. 23. Change the output power upper limit command (PMaxC) of the output power (PS) of the power generation system. By immediately setting the SOC target value to 100 [%], immediately before the power generation power PW of the wind power generator group decreases, the discharge power energy required for mitigating the fluctuation after the power generation power PW decreases is stored in the power storage system 2 Can be secured in advance. The discharge operation of the electrical storage system 2 immediately after the reduction of the generated electric power PW by the operation of reducing the output power upper limit command PMaxC to the converter capacity of the electrical storage system 2 until the sudden decrease of the PW. This makes it possible to reduce the rate of change of the output power PS to a fixed value or less (in this embodiment, the fluctuation range for 20 minutes is 10% or less). This effect makes it easy to introduce the battery-powered wind power generator group, and can effectively use natural energy.

The signal line 8 shown in FIG. 21 is composed of a network such as a LAN or a WAN, a dedicated line, or the like. In addition, even if the effect of this invention is a form which receives the generation power prediction value PP by a radio signal etc. without using the signal line 8, the effect of this invention is the same.

As described above, the wind power generation system of the present invention includes means for changing the charging rate target value SOCT of the electrical storage system 2 based on the generated power prediction value PP of the wind power generator group 1; It has a means for changing the charging rate SOC of the electrical storage system 2 based on said SOCT. Moreover, the wind power generation system of this invention is based on the generation power prediction value PP of the wind power generator group 1, The means which changes the upper limit output power command PMaxC of a wind power generation system, and based on said PMaxC And means for suppressing the output power PS below PMaxC. By the effect of this invention, even if the wind speed increases rapidly, the loss of energy by a power limitation can be avoided and natural energy can be utilized effectively. In addition, under the condition that the wind speed decreases rapidly, even when the rated capacity of the electrical storage system 2 is small, it is possible to alleviate the fluctuation of the output power PS. This facilitates the introduction of the battery-sided wind power generation system, and makes it possible to effectively use natural energy.

(Example 4)

A fourth embodiment of the present invention will be described with reference to FIGS. 28 and 29. Since the basic structure of the wind power generation system of this embodiment is the same as that of Embodiment 1, detailed description is abbreviate | omitted. The biggest feature of the present embodiment is that when the fluctuation of the power generation power PW of the wind power generator group 1 is relatively small, the output power PS of the wind power generation system depends on the first delay command of the power generation power PW. When the storage battery charges and discharges and the fluctuation of the generated electric power PW of the wind power generator group 1 exceeds the reference width, PS does not comply with the first delay command and falls within the width where PS is the reference value. The battery is charged and discharged.

The control system of the present embodiment will be described with reference to FIG. FIG. 28 is a diagram showing a control system of the charge / discharge electric power command calculation unit 3-3c of the upper level control device 3 according to the present embodiment. Since the other control system of the host controller 3 in this embodiment is the same as that of Embodiment 1, description is abbreviate | omitted.

The charge / discharge power command calculation unit 3-3c performs the first delay calculation unit 3-3c-5 on the intermediate value PWLPF in which the primary delay calculation is performed on the generated power PW of the wind power generator group 1. Write. The charge / discharge power command calculation unit 3-3c generates the intermediate value PBSOC of the charge / discharge power command for SOC management in the SOC management control unit 3-3-1. The charge / discharge power command calculation unit 3-3 generates the value PBC1 obtained by adding PWLPF to the PBSOC, and charges and discharges by operating the limiter 3-3-2 and the limiter 3-3-3. Find the median value PBC3 of the power command. The charge / discharge power command calculation unit 3-3 calculates the charge / discharge power command PBC by subtracting the PW from the intermediate value PBC3. The first limiter 3-3-2 sets the upper limit to the value obtained by adding 10% of the wind power generation system rating to the PSMin and the lower limit to the value obtained by subtracting 10% of the wind power generation system rating from the PSMax. By the effect of this limiter 3-3-2, the fluctuation of the output power PS of the wind power generation system can be suppressed to 10% or less in an arbitrary cross section for 20 minutes.

The effect of this invention is demonstrated using FIG. 29 is a diagram showing an operation example of the wind power generation system shown in the present embodiment. In the wind power generation system of the present embodiment, the output possible range R in which the variation of the output power PS of the wind power generation system is within 10% in 20 minutes is created. When the PWLPF falls within the output possible range R, the charge / discharge power of the electrical storage system 2 is controlled so that the generated power PS of the wind turbine system follows the PWLPF. When PWLPF deviates from the said output possible range R, the charging / discharging electric power of the electrical storage system 2 is controlled so that PS may correspond to the upper limit or the lower limit of the output possible range R. FIG.

By performing the control shown in this embodiment, the wind power generation system can suppress the fluctuation of the generation power PS of the wind power generation system to a predetermined value or less even if the time constant of the primary delay tracking is small. This effect makes it possible to reduce the charge / discharge power amount of the power storage system 2 as compared with the case where only the first delay tracking operation is performed. Since the amount of charge and discharge power of the electrical storage system 2 decreases, the loss which arises in the electrical storage system 2 can be reduced, and it is connected with the effective use of natural energy.

(Example 5)

A fifth embodiment of the present invention will be described with reference to FIGS. 30, 31, 32, 33, and 34. The difference from the second embodiment of the present invention is that the output power upper limit command PMaxC of the wind power generation system is determined from the stored energy of the power storage system 2.

The part different from the structure of Example 2 of this invention is demonstrated using FIG. 30, FIG. 31, FIG. 32, FIG. The charge / discharge battery command calculating section 3d-3 in the present embodiment will be described with reference to FIG. The part of the charge / discharge command unit 3d-3 of the present embodiment differs from the charge / discharge command unit 3a-3 of the first embodiment by setting the upper limit value PMaxC of the limiter 3d-3-3 to a predetermined value. Instead, it is determined by the charge rate SOC of the power storage system 2. Since other parts of the charge / discharge battery command calculating unit 3d-3 of the present embodiment are the same as those of the charge / charge battery command calculating unit 3a-3 of the second embodiment, detailed description thereof will be omitted.

Next, the power limit command calculating section 3d-4 in the present embodiment will be described with reference to FIG. The power limit command calculating section 3d-4 of the present embodiment differs from the power limit command calculating section 3a-4 of the first embodiment in that the output power upper limit value PMaxC is not a predetermined value, but the power storage system 2. This is determined by the filling rate (SOC) of. Since other parts of the power limit instruction calculating unit 3d-4 of the present embodiment are the same as those of the charge / discharge battery order calculating unit 3d-4 of the second embodiment, detailed description is omitted.

Next, with reference to FIG. 32, the operation of the output power upper limit instruction calculating section 3d-3-4 and 3d-4-3 will be described. The output power upper limit command calculating section 3d-3-4 and 3d-4-3 first store the accumulating energy E that the power storage system 2 can discharge in the accumulating energy calculating section 3d-3-4-1. Is calculated from the charging rate SOC of the electrical storage system 2. The output power upper limit command calculation unit 3d-3-4 and 3d-4-3 store in advance the output power upper limit command PMaxC corresponding to the stored energy E in advance. In (3d-3-4-2), select PMaxC.

33 shows the relationship between the stored energy E and the upper limit of the output power command PMaxC. The total discharge energy required when the power storage system discharges from the power PMaxC in accordance with the change rate of the limit of fluctuation relaxation (10% / 20 minutes) is referred to as EPMaxC. At this time, between EPMaxC and E, there is a relationship shown in equation (3).

Total discharge energy (EPMaxC) <accumulated energy (E)

By having the relationship as shown in Equation (3), even when the generated power of the wind power generator group 1 decreases sharply, the change in the output power due to the discharge of the electrical storage system 2 is regulated (10% / 20 minutes). It becomes possible to suppress below).

The effect of this invention is demonstrated using FIG. FIG. 34 shows the phenomenon that the generated power PW of the wind power generator group decreases sharply at time t0. Fig. 34A is a diagram showing the operation when there is no upper limit of the output power shown in the first embodiment. In Fig. 34A, as the power generation power increases in the period until time t0, the SOC target range also increases. As shown in Fig. 34A, in order for the SOC to comply with the SOC target range, a time delay may occur. For this reason, the idea that the accumulated energy required for discharge is insufficient may occur. In FIG. 34A, the windmill output suddenly decreases at time t0, and after that, the power storage system 2 performs a discharge operation in order to alleviate power fluctuations. However, at time t1, since the SOC reaches 0% (the accumulation energy is insufficient), the discharge operation cannot be performed, and a large power fluctuation occurs.

On the other hand, in the control system of the present embodiment shown in Fig. 34B, the upper limit of the output power PMaxC is changed in accordance with the accumulated energy (or S0C) of the power storage system. Due to the effect of this PMaxC, the output power PS is small even at time t0. Even when the windmill output decreases sharply at time t0, the accumulated energy sufficient to discharge the power storage system 2 is secured. Power fluctuation can be suppressed below the specified value.

In addition, the method of limiting the output power PS of the wind power generation system shown in the present embodiment is not limited to the charge / discharge control of the storage battery shown in Embodiment 1, but is the primary method of generating power generation PW as a control method of the storage battery. Other control methods, such as depending on the delay signal, may be used.

As shown in the present embodiment, even when the output power PS of the wind power generation system is limited in accordance with the stored energy of the electrical storage system 2, the occurrence of the sudden decrease in the generated power of the wind power generator group 1 occurs. Therefore, it is possible to more reliably suppress the rate of change of the electric power below the specified value. By this effect, introduction of a power plant can be made easy, and natural energy can be utilized effectively.

(Example 6)

A sixth embodiment of the present invention will be described with reference to FIGS. 35 and 36. 30 shows the configuration of the wind power generation system of this embodiment. With respect to the component in FIG. 35, the same thing as Example 1 shows the same structure. The biggest feature of this embodiment is the charge factor (SOC) of each power storage device 2-1-1, 2-1-2,?,?,?, 2-1-m, which constitutes the power storage system 2. Are controlled by different values.

In this embodiment, a case where a lead battery, a sodium sulfur battery, or a lithium battery which is a secondary battery is used as a storage battery constituting a power storage device is assumed. In the secondary battery, the charge / discharge power value changes depending on the SOC depending on the characteristics thereof. In general, when the SOC of the storage battery is high, the amplitude of the chargeable power decreases. On the contrary, when the SOC is low, the amplitude of the dischargeable power tends to decrease. FIG. 36 shows the charge rate SOC of the power storage devices 2-1-1, 2-1-2,?,?,?, 2-1-m, and chargeable and dischargeable electric powers of FIG. Drawing. When the charge rate SOC of the power storage devices 2-1-1, 2-1-2,?,?,?, 2-1-m has the same characteristics as in FIG. 36, the charge rates of the power storage devices are different. By controlling to a value, the range of charge / dischargeable electric power can be increased.

37A and 37B, the effect of this embodiment will be described. In this embodiment, the power storage system 2 is composed of all 10 power storage devices 2-1-1, 2-1-2,?,?,?, 2-1-10. In addition, the capacity of each power storage device is set to 600 [kWh] as a rating. Fig. 37A shows a case where all SOCs of the power storage device are controlled to the same value (= 40%). In this case, from the relationship between the SOC of each power storage device and the charge / dischargeable power (FIG. 36), the chargeable power in the entire power storage system is 40% and the dischargeable power is 40%. On the other hand, Fig. 37 (b) shows a case where the SOC of the power storage device is changed for each power storage device. Specifically, the case where six SOCs of power storage devices 2-1-1 to 2-1-6 are controlled by SOC at 60% and the remaining four are controlled by SOC 10%. The amount of energy stored in the power storage system 2 as a whole is 2400 [kWh], which is the same as when the SOC is unified. In this case, the chargeable power in the entire power storage system is 40%, but the dischargeable power is expanded to 64%. By increasing the dischargeable power, the range in which the fluctuation can be reduced by the charge / discharge operation of the power storage system 2 is expanded.

The upper controller 3d shown in FIG. 35 is capable of charging and discharging electric power in the entire electrical storage system 2 while the average SOC of the electrical storage system 2 satisfies a constant condition or a condition where the accumulated energy is constant. The SOC target value of each storage battery 2-1-1,?,?, 2-1-10 is determined so as to be the maximum.

By the effect of this embodiment, the charge and discharge possible power range of the power storage system 2 is expanded, and the range in which fluctuation can be alleviated by the charge and discharge operation is expanded. For this reason, the capacity | capacitance of the electrical storage system 2 required for a wind power generation system can be reduced in order to reduce a fluctuation. The capacity reduction of the electrical storage system facilitates the introduction of the battery-powered wind power generation system, which leads to the effective use of natural energy.

The present invention can be applied to other power generation systems with large fluctuations in output power instead of the wind power generator group. Specifically, the present invention can be applied to a solar power generation system, a wave power generation system, a power generation system combining these, or the like instead of the wind power generator group.

1 is a diagram showing the configuration of a wind power generation system in a first embodiment of the present invention;

2 is a view showing an example of a wind turbine generator according to the first embodiment of the present invention;

3 is a view showing an example of a wind turbine generator according to the first embodiment of the present invention;

4 is a view showing an example of a wind turbine generator according to the first embodiment of the present invention;

5 is a view showing an example of a wind turbine generator according to the first embodiment of the present invention;

6 is a view showing an example of a power storage device in a first embodiment of the present invention;

7 is a view showing the output power of the wind power generation system in the first embodiment of the present invention;

8 is a diagram for explaining a control system of an upper level controller according to the first embodiment of the present invention;

9 is a diagram showing a filling rate target value creating means in the first embodiment of the present invention;

Fig. 10 is a diagram showing the maximum value / minimum value calculating means in the first embodiment of the present invention;

Fig. 11 is a diagram showing charge / discharge electric power command creating means in the first embodiment of the present invention;

12 is a diagram showing a charge rate management means in the first embodiment of the present invention;

Fig. 13 is a diagram showing the power limit command creating means in the first embodiment of the present invention;

14 is a view showing the chargeable electric power calculating means in the first embodiment of the present invention;

15 is a diagram showing an operation example of a wind power generation system according to the first embodiment of the present invention;

16 is a diagram showing an operation example of a wind power generation system according to a first embodiment of the present invention;

17 is a view showing the effect of the present invention in the first embodiment of the present invention;

Fig. 18 is a diagram showing charge / discharge electric power command creating means in the second embodiment of the present invention;

Fig. 19 is a diagram showing the power limit instruction creating means in the second embodiment of the present invention;

20 (a) is a diagram showing an example of the operation of the wind power generation system when the upper limit of the system output in the second embodiment of the present invention is not set.

20 (b) is a diagram showing an example of the operation of the wind power generation system in the case where the system output upper limit is set in the second embodiment of the present invention;

21 is a diagram showing the configuration of a wind power generation system in a third embodiment of the present invention;

Fig. 22 is a diagram showing the filling factor target value creating means in the third embodiment of the present invention;

Fig. 23 is a diagram showing charge / discharge electric power command creating means in the third embodiment of the present invention;

Fig. 24 is a diagram showing the power limit instruction creating means in the third embodiment of the present invention;

25 is a diagram showing an output power upper limit calculation means in the third embodiment of the present invention;

Fig. 26 (a) is a diagram showing an example of the operation when the power generation power prediction value of the wind power generation system in the third embodiment of the present invention is not used;

Fig. 26 (b) is a diagram showing an example of operation in the case of using the generated power predicted value of the wind power generation system according to the third embodiment of the present invention;

27 (a) is a diagram showing an example of the operation when the generated power prediction value of the wind power generation system in the third embodiment of the present invention is not used;

27 (b) is a diagram showing an example of operation in the case where the generated power prediction value of the wind power generation system in the third embodiment of the present invention is used;

Fig. 28 is a diagram showing charge / discharge electric power command creating means in the fourth embodiment of the present invention;

29 is a diagram showing an operation example of a wind power generation system according to a fourth embodiment of the present invention;

Fig. 30 is a diagram showing charge and discharge electric power command creating means in the fifth embodiment of the present invention;

Fig. 31 is a diagram showing the power limit instruction creating means in the fifth embodiment of the present invention;

32 is a diagram showing a power limit instruction creating means in a fifth embodiment of the present invention;

33 is a diagram illustrating a relationship between accumulated energy and a power limit command in the fifth embodiment of the present invention;

34 (a) is a diagram showing a control operation of Example 1 in the embodiment of the present invention;

34B is a diagram showing a control operation of Example 5 in the embodiment of the present invention;

35 is a diagram showing the configuration of a wind power generation system in a sixth embodiment of the present invention;

36 is a view showing the charge / discharge possible range of the power storage device in the sixth embodiment of the present invention;

37 (a) is a diagram showing a conventional charge rate control in the sixth embodiment of the present invention;

Fig. 37 (b) is a diagram showing the filling rate control of the present invention in the sixth embodiment of the present invention.

[Description of Drawings]

1: Wind power generator group 1-1: SCADA

1-1-1, 1-1-2,?,?,?, 1-1-n: Wind power generator

1-1-1-1, 1-1-la-l, 1-1-lb-1, 1-1-1c-l: blade

1-1-1-2, 1-1-la-2, 1-1-lb-2, 1-1-1c-2: Anemometer

1-1-1-3, 1-1-1a-3, 1-1-lb-3, 1-1-1c-3: Gearbox

1-1-1-4: DC excitation synchronous generator 1-1-1a-4: AC excitation synchronous generator

1-1-1b-4: Permanent magnet generator or induction generator

1-1-1c-4: Induction Generator

1-1-1-5, 1-1-1-6, 1-1-1a-6, 1-1-1b-6, 2-1-1-2: Power converter

1-1-1-7, 1-1-la-7, 1-1-1b-7, 1-1-1c-7: Linked Transformer

1-1-1-8, 1-1-1a-8, 1-1-1b-8, 1-1-1c-8, 2-1-1-4: circuit breaker

1-1-1-9: Excitation device 2: Power storage system

2-1-1, 2-1-2,?,?,?, 2-2-m: Power storage device

2-1-1-1: secondary battery 2-1-1-3, 4: linked transformer

3, 3a, 3b, 3d: upper controller

3-1: SOC target value calculator 3b-1-1: SOC target value calculator

3b-1-2: power prediction value change rate calculator

3b-1-3: Converter 3-2: Max./min.

3-3, 3a-3, 3b-3, 3c-3, 3d-3: charge and discharge power command calculation unit

3-3-1: SOC management control unit

3-3-1-1, 3-3-1-1,?,?,?, 3-3-1-m: Charge / discharge power command calculation unit

Limiter: 3-3-2, 3-3-3, 3a-3-3, 3d-3-3

3b-3-4, 3d-3-4: Output power upper limit command calculation unit

3d-3-4-1: Accumulated energy calculator

3d-3-4-2: Output power upper limit command selector

3-3c-5: 1st delay calculation unit

3-4, 3a-4, 3b-4, 3d-4: Power limit command calculation unit

3-4-1: Rechargeable Power Computing Unit

3a-4-2, 3b-4-2, 3d-4-2: Minimum value selection calculator

3b-4-3, 3d-4-3: Output power upper limit command calculation unit

3-4-1-1, 3-4-1-2,?,?,?, 3-4-1-m: Rechargeable power calculator

3-5: charge / discharge power command distribution unit 5: power system

6 power meter 7 power meter

8: signal line 9: power generation predictor

Claims (15)

A wind power generator group constituted by one or more wind turbines, a power storage system constituted by one or more power storage units, an upper control unit that controls the wind power generator group and the power storage system, and the wind power generator In the wind power generation system having a generation power detection unit for detecting the generation power of the group, The upper control device, An output power recording memory for recording an output power that is a sum of generated power of the wind power generator group and charging / discharging power of the power storage system; If the predetermined period from the past to the present is the first period and the other predetermined period from the present to the future is the second period, the predetermined value is set to the minimum value of the output power in the first period recorded in the output power recording memory. And add an upper limit value of the output range of the output power in the second period, subtract a predetermined value from the maximum value of the output power in the first period recorded in the output power write memory in the second period. Obtaining a lower limit value of the output range of the output power, and using the information of the detected value of the current generation power detection unit, when the generated power of the wind turbine group deviates from the output range in the second period, And a charge / discharge power command calculator for calculating the charge / discharge power command of the power storage system from the power deviating from the output range. The power storage system is characterized by comprising a charge-discharge power control device for controlling the charge-discharge power in accordance with the charge-discharge power command. The method of claim 1, The host controller includes means for calculating a charge rate target range of the charge rate of the power storage system; The power storage system having means for charging and discharging when the generated electric power of the wind turbine group is out of the output range, or when the charge rate of the power storage system is outside the charge rate target range. A wind power generation system characterized by the above. The method of claim 1, The upper control device includes: means for calculating a first value obtained by performing a first delay calculation on the generated power of the wind turbine generator group; Means for performing charge / discharge control of the power storage system so that the output power of the wind power generation system conforms to the first value when the first value is within the output range; And means for creating a charge / discharge battery command of the power storage system so that the output power of the wind power generation system follows an upper limit or a lower limit of the output range when the first value deviates from the output range. Wind power generation system. 3. The method of claim 2, And a means for determining the charge rate target range of the power storage system from the power generation of the wind power generator group. The method of claim 1, The first period is a constant value of 20 minutes or less, and the second period is a constant value of 1 minute or less. The method according to claim 2 or 4, The higher level control device includes: means for receiving a generation power prediction value for predicting future generation power of the wind turbine group; And a means for adjusting the charge rate target range in accordance with the power generation power prediction value. The method of claim 1, The host controller includes means for creating a power limit instruction for the wind turbine generator group, The wind power generation device group, the wind power generation system characterized in that it comprises a power generation limiting means for limiting the generation power to below the power limit command. 8. The method of claim 7, The host controller includes means for calculating chargeable power of the electrical storage system, The means for creating the power limit instruction is a sum of a predetermined value set by the relationship between the minimum value of the output power in the first period and the allowable fluctuation range of the chargeable power and the output power of the wind power generation system. A wind power generation system characterized by a restriction command. 8. The method of claim 7, The higher level control device includes: means for receiving a power generation prediction value of the wind turbine group; And a means for changing the power limit command in accordance with the generated power prediction value. The method according to claim 8 or 9, The host controller includes means for calculating an output power upper limit command of the output power; And a means for limiting the output power to the output power upper limit command or less by a charging operation of the power storage system and a power limiting operation of the wind power generator group. The method of claim 10, The output power upper limit command is a constant value, is equal to or less than the rated power generation value of the wind power generator group, and is equal to or more than the rated capacity of the converter constituting the power storage system. The method of claim 10, And the output power upper limit command is adjusted according to a predicted power generation value of the wind power generator group. The method of claim 10, And the output power upper limit command is adjusted according to the charging rate of the power storage system or the accumulated energy of the power storage system. delete delete

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