JP2013219941A - Control method and control device of power generation system using renewable energy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation system using renewable energy capable of suppressing a fluctuation of electric power output from a wind farm to an electric power system and maintaining a constant output.SOLUTION: A power generation system using renewable energy comprises a meteorological observation system 9 outside a wind farm 100, and a host controller 3 controls a wind power generation system 1 having a group of wind power generation devices, and a power storage system 2. In order to control a fluctuation of output power of the group of wind power generation devices to be in a predetermined possible output range, the host controller 3, when issuing a control command to compensate for the output power by charge/discharge of the power storage system 2, predicts the fluctuation of the output power of the group of wind power generation devices in the near future on the basis of meteorological information measured by the meteorological observation system 9, determines whether or not the predicted output power deviates from the possible output range, and issues a command to change at least one of a target value of a charging rate of the power storage system and a limit value of the charge/discharge power of the power storage system as the control command of the power storage system 2 when the predicted output power deviates from the possible output range.

Description

  The present invention relates to a control method and a control device for a renewable energy-based power generation system, and more particularly, to use a renewable energy composed of a plurality of wind power generators that supply power generated using wind energy to a power system. The present invention relates to a power generation system control method and a control apparatus.

  In recent years, the introduction of wind power generation has become popular worldwide as one of the measures against global warming. When introducing a large amount of wind power generation, it is often installed as a wind farm in which multiple wind power generation devices are installed in a certain area from a cost-effective viewpoint, and these wind power generation devices are controlled and operated in an integrated manner. It has become.

  Until now, the proposal like patent document 1 is made | formed regarding a wind farm and each wind power generator. Patent Document 1 discloses a technique for mitigating fluctuations in the output of a wind power generator due to fluctuations in wind speed by charging and discharging a power storage system provided in a wind farm.

JP 2009-79559 A

  By the way, as wind power generators whose power generation output fluctuates depending on weather conditions are increasingly introduced into the power system, there are concerns about the effects of maintaining the voltage and frequency of the power system when the number of wind power generators further increases in the future.

  Speaking of frequency maintenance, power companies in each region have so far balanced demand and supply mainly by combining various power sources against fluctuations in demand. However, when a large amount of wind power generation is connected to the power system, a negative load is superimposed on the conventional demand. Depending on the combination of fluctuations in demand and wind power output, it is expected that a higher supply-demand adjustment capability will be required.

  Demand fluctuation is thought to be a superposition of pulsating components with various amplitudes and periods with small variation widths and irregular fluctuations, and the components are minute fluctuations of up to several minutes, ranging from several minutes to about 10 to several minutes. Are divided into three main components of a long period fluctuation of 10 minutes or more. The aforementioned three components are also included in the power generation output of wind power generation.

  With respect to the demand fluctuation, a minute fluctuation up to a few minutes can be adjusted by governor-free operation using a governor of the power plant. For short-period fluctuations with a period of several minutes to about 10 and several minutes, frequency deviations are detected and controlled by changing the generator output of the frequency-adjusted power plant, and this is controlled by load frequency control (LFC) It is called. Long-period fluctuations with longer periods are controlled by sending power generation commands to each power plant in consideration of economic efficiency, and this is called economic load distribution control (ELD). Yes.

  When a large amount of wind power generation is introduced, load frequency control (LFC) is particularly problematic. When fluctuations in wind power generation output are superimposed on demand (load) fluctuations, it is conceivable that the installed capacity of the frequency adjustment power plant will be insufficient. However, simply increasing the installed capacity of the frequency-regulated power plant is an economic burden and requires some alternative means.

  Up to now, as described in Patent Document 1, a wind farm has been provided with a power storage system, and charging and discharging is performed using a maximum value and a minimum value of the sum of the output power of the wind power generator group and the power storage system in the past for a predetermined time. From this, the possible output range in the future of the next control cycle is set. As a result, the power storage system performs the charge / discharge operation only when the generated power of the wind power generator group deviates from the output possible range, or when the charge rate of the storage battery deviates from the target range of the charge rate. As a result, it is possible to alleviate fluctuations in the LFC region of the output power of the wind power generation device group and reduce losses associated with charging and discharging of the power storage system.

  However, sudden changes in wind speed, especially when the wind speed suddenly weakens, or when the wind power generator stops due to strong winds due to the protection function, the wind power output suddenly decreases greatly deviating from the possible output range. If the capacity exceeds the capacity of the stored power storage facility, there is a possibility that the predetermined output fluctuation mitigation performance cannot be exhibited without completely mitigating rapid fluctuations.

  The present invention has been made in view of the foregoing points, and the object of the present invention is to maintain a predetermined output fluctuation mitigation performance even when a sudden and large output power fluctuation of the wind power generator group occurs. It is an object of the present invention to provide a control method and control apparatus for a renewable energy-based power generation system.

  In order to achieve the object, a wind power generator group (for example, a wind power generation system 1) configured by one or more wind power generators, a power storage system configured by one or more power storage devices, and a wind power generator group And a renewable energy-use power generation system (for example, wind farm 100) having a host controller that controls the power storage system, wherein the host controller is configured to output fluctuations in the output power of the wind power generator group within a predetermined output possible range. In order to control the power storage system to compensate by charging / discharging the power storage system, predicting the near-future output power fluctuations of the wind power generator group based on weather information, the predicted output power, It is determined whether or not the output range is exceeded. And changes the command at least one of the target values of the rate and limit values of the charge and discharge power of the power storage system.

  ADVANTAGE OF THE INVENTION According to this invention, the fluctuation | variation of the abrupt and big output electric power which generate | occur | produces in a renewable energy utilization electric power generation system can be estimated in advance, and an output fluctuation | variation can be suppressed to a predetermined range.

It is a block diagram which shows one Embodiment of the wind farm of this invention. It is a block diagram which shows arrangement | positioning of the weather observation apparatus in one Embodiment of this invention. It is a characteristic view showing the fluctuation | variation of the output electric power in one Embodiment of this invention. It is a block diagram which shows the structure of the high-order controller in one Embodiment of this invention. It is a flowchart which shows operation | movement of the high-order controller in one Embodiment of this invention. It is a characteristic view which shows the wind speed fluctuation | variation prediction method based on the weather information of the weather observation apparatus in one Embodiment of this invention. It is explanatory drawing which shows the example of a prediction at the time of the rapid decrease in wind speed in one Embodiment of this invention. It is a characteristic view which shows the change operation | movement of the charging / discharging limit value of the electrical storage apparatus in one Embodiment of this invention. It is a figure which shows the function which displays the states of a wind power generation system, an electrical storage apparatus, etc. in one Embodiment of this invention. It is a characteristic view which shows the control method of a wind power generation system and an electrical storage system with respect to the output electric power fluctuation estimated value in one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram of a wind farm according to an embodiment of the present invention. As shown in FIG. 1, a wind farm 100 as a power generation system using renewable energy is connected to a power system 5 at one location via a connection transformer 4 and supplies power. The wind farm 100 includes a wind power generation system 1 (wind power generation device group), a power storage system 2, a host controller 3, an output power PW of the wind power generation system 1, and the like, and a power meter 6 that transmits the output power PW to the host controller 3. And a wattmeter 7 that measures the charging power and discharging power PB that is the charging power and discharging power of the power storage system 2 and transmits them to the host controller 3. It should be noted that the relationship of (Equation 1) is established between the output power PS of the wind farm 100 and PW and PB.
(Equation 1) PS = PW + PB

  At least one meteorological observation device 9 is installed at a position distant from the wind farm 100 in a generally upwind direction of a prevailing wind direction such as a seasonal wind in the wind farm 100. The meteorological observation device 9 includes one or a plurality of pieces of weather information such as wind speed, wind direction, temperature, humidity, and atmospheric pressure, the time when the meteorological information is measured, and the point where the weather observation device 9 is installed. Position information such as latitude, longitude, altitude, etc., stored sequentially or for a fixed time from the weather measurement value processing / transmission device 91 is collected and transmitted to the host controller 3 of the wind farm 100 via the communication network 8. .

  The elephant observation device 9 and the meteorological measurement value processing / transmission device 91 may be provided as a configuration of the wind farm 100 or may be configured to use an external device. Moreover, the installation position of the weather observation device 9 is not limited to the windward direction, and may be located where the wind speed in the wind farm 100 can be measured satisfactorily. Details will be described later with reference to FIG.

  The position where the weather observation apparatus 9 is installed has a temporal correlation with the fluctuation of the wind speed generated in the wind farm 100, and the time until the fluctuation of the wind speed measured by the weather observation apparatus 9 reaches the wind farm 100. , It is set to be longer than the time required until the control is performed.

  For example, the wind speed in the dominant wind direction observed at the wind farm 100 is Va (m / sec), the fluctuation level of the output power that can be generated by the wind farm 100 is PFmax (pu), and the wind farm 100 The fluctuation level of the required output fluctuation mitigation requirement is A (pu), the evaluation time of the fluctuation mitigation requirement is B (sec), the maximum value of charge / discharge power of the power storage system is PBmax (pu), and the rated output of the wind power generation system Is PWmax (pu), the distance La between the wind farm 100 and the weather observation device 9 is expressed by (Expression 2).

    (Expression 2) La ≧ Va × PFmax × B / A × (1−PBmax / PWmax) (m)

  In addition, if the weather observation apparatus 9 has the function to measure the said weather information and transmit with respect to the wind farm 100, the weather observation apparatus 9 installed in another wind farm or a solar power station etc. May be used.

  Returning to FIG. 1, the wind power generation system 1 includes a plurality of wind power generation apparatuses 111, 112,. The wind power generators 111, 112,..., 11n are wind power generators that are variable in rotation speed and pitch and can be controlled. SCADA is an abbreviation for Supervisory Control And Data Acquisition.

  The SCADA 11 plays a role of collecting operating information such as operating status of the wind power generation system and generated power. At the same time, the SCADA 11 receives the command for limiting the generated power of the wind power generation system 1 from the host controller so that the sum of the generated power of the individual wind power generators 111, 112,. , 11n are given to each wind power generator 111, 112,..., 11n respectively.

  The power storage system 2 includes one or more power storage devices 211, 212, ..., 21m. The power storage devices 211, 212,..., 21 m can charge the generated power of the wind power generation system 1 or discharge the stored power in accordance with the charge / discharge power command from the host controller 3. In addition, each of the power storage devices 211, 212,..., 21m measures a state of charge (SOC) of the storage battery, and transmits the SOC value to the host controller 3. The power storage devices 211, 212,..., 21 m are configured by any one of a lead storage battery, a sodium sulfur battery, a redox flow battery, a lithium ion battery, a nickel hydrogen battery, and a lithium ion capacitor, or a combination thereof.

Note that the SOC can be generally expressed by Equation (3).
(Equation 3) SOC = remaining capacity (Ah) / full charge capacity (Ah) * 100 (%)
It is a unit that indicates the state of charge of the battery, and indicates the ratio of the remaining charge to the capacity of the battery when fully charged. That is, when the SOC is 100%, a fully charged state is indicated, and the capacity defined by Ah (ampere hour) can be discharged. Normally, the SOC is calculated by integrating the charged / discharged current value over time. Alternatively, there is a method in which the voltage of the battery in a fully charged state and the voltage in the empty state are measured in advance and approximated from the battery voltage.

  The display device 10 is installed in a monitoring room (not shown) of the wind farm 100 or a facility (not shown) for monitoring the wind farm outside the wind farm 100, and wind power generation processed by the host controller 3 One or more pieces of information such as the operating state of the system 1, the power generation output, the output restriction command, the charging rate of the power storage system 2, the charge / discharge limit value, the output fluctuation record of the wind farm 100, the compliance rate with respect to a predetermined output fluctuation, etc. It has a function to display combined information.

  FIG. 2 is a block diagram showing the arrangement of the weather observation apparatus in one embodiment of the present invention. When the prevailing wind direction such as a seasonal wind is not seen due to the geographical conditions of the wind farm 100, or when the prevailing wind direction changes according to time, season, etc., a plurality of weather observation devices 9a, 9b and 9c are installed.

  For example, when a prevailing wind direction such as a seasonal wind is not seen, by installing at least three meteorological observation devices 9a, 9b, and 9c, the weather that is generally upwind with respect to the wind farm 100 in any wind direction There will be an observation device, and by combining the weather information of any one of the weather observation devices or a plurality of weather observation devices, it is possible to predict in advance a sudden change in output generated in the wind farm 100. Become.

  The meteorological observation devices 9a, 9b, and 9c collect the weather information stored sequentially or for a fixed time via the meteorological measurement value processing / transmitting devices 9a1, 9b1, and 9c1, respectively, and wind farms via the communication network 8. The data is transmitted to 100 upper controllers 3 (see FIG. 1).

  FIG. 3 is a characteristic diagram showing fluctuations in output power according to an embodiment of the present invention. In FIG. 3, the output power PS of the wind farm 100 varies with the variation of the wind speed. In order to mitigate the output fluctuation PS, the output fluctuation is always set to a constant value (for example, the rating 10 of the wind power generation system 1 shown in FIG. 1) during a certain time (for example, within 20 minutes) starting from an arbitrary time. % Or less) is effective. If the rating of the wind power generation system 1 is about 10% or less, the influence on the power system 5 can be reduced even if many wind power generation groups are connected.

  Specifically, in the normal output power fluctuation mitigation control, the following control cycle (FIG. 3) is applied to the maximum value PSMax of the output power PS for the past 19 minutes and the minimum value PSMin of the output power PS for the past 19 minutes. Then, the charge / discharge power of the power storage system 2 is determined so that the output power PS after 1 minute) falls within the output possible range R that is a range between the upper limit value PSMin + 10% and the lower limit value PSMax-10%. Thereby, it is possible to keep the power fluctuation for 20 minutes starting from an arbitrary time within 10% or less of the rating of the wind power generation system 1.

  However, like the output power PS in the future of FIG. 3, the predicted output power PS (predicted output power) decreases beyond the operable range, and the output power corresponding to the excess of the output possible range R is stored. When the limit value of the dischargeable power of the system 2 is exceeded, the output power PS of the wind farm 100 deviates from the outputable range R and a fluctuation of 10% or more occurs. In order to cope with this, control that is a feature of the present embodiment will be described with reference to FIG.

  FIG. 4 is a block diagram showing the configuration of the host controller in one embodiment of the present invention. This will be described with reference to FIG. The host controller 3 includes a wind speed fluctuation prediction means 31 that predicts wind speed fluctuations using weather information measured by the weather observation apparatus 9 and transmitted via the weather measurement value processing / transmission apparatus 91, and wind speed fluctuations based on the wind speed fluctuation. Output fluctuation prediction means 32 that predicts fluctuations in the output power PS of the farm 100, output fluctuation determination means 33 that determines how much the predicted value of output fluctuation exceeds the output possible range R (operable range), and output A fluctuation mitigation control means 34 that performs normal fluctuation mitigation control when the fluctuation is not abrupt; a windmill / storage battery control determination means 36 that decides the control means of the wind power generation system 1 and the power storage system 2 when the output fluctuation is abrupt; The state of the wind power generation system 1 and the power storage system 2 is monitored, and the state of the windmill / storage battery is transmitted to the fluctuation mitigation control means 34 and the windmill / storage battery control determination means 36. A stage 37, a weather measurement value processing and transmission apparatus 91, SCADA11, the power storage system 2, the receiving means 38 for receiving the display device 10 and the data.

  In the present embodiment, as described above, the elephant observation device 9 and the meteorological measurement value processing / transmission device 91 may be provided as the configuration of the wind farm 100, or may be configured to use an external device. In the case of using an external one, for example, the Japan Meteorological Agency automatically performs meteorological observation at over 1,300 locations nationwide by an AMeDAS (Automated Meteorological Data Acquisition System). The wind speed fluctuation prediction means 31 may predict the wind speed fluctuation based on the terrain information of the installation location of the wind farm 100 and the weather information of the regional weather observation system.

  FIG. 5 is a flowchart showing the operation of the host controller according to the embodiment of the present invention. This will be described with reference to FIGS. 1 and 4 as appropriate. The wind speed fluctuation prediction means 31 of the host controller 3 takes in the weather information measured by the weather observation device 9 (processing S51), and predicts near-future wind speed fluctuations based on the taken-in weather information. The output fluctuation prediction unit 32 predicts fluctuations in the output power PS generated in the wind farm 100 (processing S52). The output fluctuation determination means 33 determines whether or not the fluctuation of the output power PS whose output is predicted deviates from the output possible range R (processing S53).

  In the process S53, when the fluctuation of the output power PS whose output is predicted does not deviate from the output possible range R (No in the process S53), that is, the fluctuation of the output fluctuation PW of the wind power generation system 1 is the charge / discharge of the power storage system 2. If the power can be absorbed within the limit value of the possible power, the fluctuation mitigation control unit 34 performs charge / discharge control of the power storage system 2 disclosed in, for example, Patent Document 1 as normal fluctuation mitigation control (see FIG. 3). (Process S54).

  In the process S53, when the fluctuation of the output power PS whose output is predicted deviates from the output possible range R (Yes in the process S53), that is, the fluctuation of the output power PW of the wind power generation system 1 is the charge / discharge of the power storage system 2. If the power cannot be absorbed within the limit value of the power PB, is the predicted output power PS increasing (Step S55, Yes) or decreasing (Step S55, No), the predicted output power PS? Depending on the fluctuation rate (ΔP / Δt), the predicted fluctuation level (ΔP) of the output power PS, the current SOC value of the power storage system 2, etc. 1 is controlled (process S56 or process S57).

  In FIG. 5, the variation rate is represented by ΔP / Δt, and the variation level is represented by ΔP. At this time, as an example, according to the variation rate (ΔP / Δt) and the variation level (ΔP), the sudden change occurrence control menu in FIG. 5 is prepared in advance and the combination is controlled. In the present embodiment, the variation rate (ΔP / Δt) is described as three types of large, medium, and small, and the variation level (ΔP) is described as three types of large, medium, and small.

  The sudden change prediction control menu is a menu at the time of wind weakness (when the wind is predicted to weaken) described in the lower part of FIG. 5, A: SOC target value increase, B: Storage system discharge limiter increase , C: wind turbine output limit (tilt reduction control) start, menu of wind strength (when wind is predicted to increase), D: SOC target value decrease, E: storage system charge limiter increase, F: There is a wind turbine output limit (inclination increase control) start.

  The inclination reduction control of the wind turbine output restriction refers to control that decreases the output power PW (total generated power of the wind turbine) of the wind power generation system 1 with time, and is also referred to as ramp control. As the structure of the wind turbine for performing the lamp control, it is desirable that variable pitch control is possible. The variable pitch control means detecting the wind speed / generator output and controlling the blade mounting angle (pitch angle).

  Another windmill structure is a windmill equipped with a blade passage area adjusting device having a blade tilting mechanism that tilts a plurality of blades supported by the rotor head in the axial direction of the rotor head to change the blade passage area. Even in such a case, the lamp control can be performed by reducing the inclination angle from the vertical plane in the axial direction.

  The process S57 (when the predicted output power PS is decreasing) will be described. When the predicted fluctuation rate (ΔP / Δt) and fluctuation level (ΔP) are both small, since there is a time margin until the output power PS falls below the output possible range R, the windmill / storage battery control determining means 36 A control command is issued to increase the SOC target value (menu A selection). This is because, when the output power PS decreases, by setting the SOC target value higher than normal before the sudden decrease occurs, sufficient SOC can be secured when the sudden decrease occurs, and even when the power storage system 2 discharges when the sudden decrease occurs This is to avoid a situation in which fluctuation mitigation control cannot be performed due to SOC exhaustion and output fluctuation occurs.

  When the predicted fluctuation rate (ΔP / Δt) is small and the fluctuation level (ΔP) is medium, the windmill / storage battery control determining unit 36 displays the menu B for increasing the discharge limiter of the power storage system in the menu A. In addition, a control command is issued (menu A + B selection). In addition, when the predicted fluctuation rate (ΔP / Δt) is small and the fluctuation level (ΔP) is large, a menu C for starting wind turbine output restriction (inclination reduction restriction) is added to A in the menu. A control command is issued (menu A + C is selected).

  Usually, it is the output power PW that becomes a problem when the wind weakens. Finally, the output power PS becomes a problem including the charge / discharge power PB that compensates for the output fluctuation of the output power PW. For example, it is desirable that the output fluctuation in an arbitrary 20 minutes be 10% or less of the wind turbine rated output. That is, even if the output power PS decreases by the same amount (for example, 20%), if it occurs within 20 minutes, there may be a problem (for example, a system stability problem). If it changes slowly over more than a minute, there is no problem. Therefore, in this embodiment, if it can be predicted in advance that the output power PW of the wind power generation system 1 will decrease, the output power PW is slowly reduced in advance by slope reduction control, so that the fluctuation within 10% is achieved in 20 minutes. Can be suppressed.

  As described above, by combining the menus A, B, and C, the predicted fluctuation rate (ΔP / Δt) and fluctuation level (ΔP) can be controlled. For example, when the predicted fluctuation rate (ΔP / Δt) is large and the fluctuation level (ΔP) is large, the windmill / storage battery control determining unit 36 selects menus A, B, and C (menu A + B + C is selected) and a control command is issued.

  When the fluctuation rate (ΔP / Δt) and the fluctuation level (ΔP) are both large, the windmill / storage battery control determining unit 36 uses the discharge limiter of the power storage system to increase the discharge output in the menu A for increasing the SOC target value. In addition, a menu B for changing is added, and further, a menu C for limiting the output power PW of the wind power generation system 1 with a slope so as to decrease with time is added by the time of sudden change occurrence, and a control command is given. As a result, the output power PW of the wind power generation system 1 is decreased before the decrease of the output power PW of the wind power generation system 1 due to the weakening of the wind. Accordingly, the reduction range of the output power PS to the power system 5 can be reduced.

  Furthermore, by increasing the SOC of the power storage system 2 until the decrease in the output power PW occurs, the dischargeable capacity of the power storage system 2 when the output power PW of the wind power generation system 1 is decreased is increased. After the decrease in the output power PW of the wind power generation system 1 occurs, it is possible to extend the time during which the decreased output power PW can be mitigated by the discharge of the power storage system 2. In addition, by changing the discharge limiter of the power storage system 2 in the direction in which the discharge output increases, when the output power PW of the wind power generation system 1 decreases due to the weakening of the wind, eventually, due to the discharge of the power storage system 2, It is possible to reduce the reduction range of the output power PS due to the weakening of the wind.

  Next, the process S56 (when the predicted output power PS is increasing) will be described. When the predicted fluctuation rate (ΔP / Δt) and fluctuation level (ΔP) are both small, there is a time margin until the output power PS exceeds the output possible range R. A control command is issued to decrease the SOC target value (menu D selection). This is because when the output power PS increases, the SOC target value is made lower than normal before the increase occurs, so that the actual use area of the SOC can be secured when the increase occurs, and the power storage system 2 when the sudden increase occurs This is because even in the case of charging, fluctuation mitigation control cannot be performed due to exhaustion of the actual use area, and a situation in which output fluctuation occurs is avoided.

  When the predicted fluctuation rate (ΔP / Δt) is small and the fluctuation level (ΔP) is medium, the windmill / storage battery control determining unit 36 displays the menu E for increasing the charging limiter of the power storage system in the menu D. In addition, a control command is issued (menu D + E selection). In addition, when the predicted fluctuation rate (ΔP / Δt) is small and the fluctuation level (ΔP) is large, a menu F for starting wind turbine output restriction (inclination increase restriction) is added to menu D. Give a control command (select D + F in the menu).

  By combining the menus D, E, and F as described above, it is possible to control the predicted fluctuation rate (ΔP / Δt) and fluctuation level (ΔP). For example, when the predicted fluctuation rate (ΔP / Δt) is large and the fluctuation level (ΔP) is large, the windmill / storage battery control determining unit 36 selects menus D, E, and F (menu D + E + F is selected) and a control command is issued.

  When the fluctuation rate (ΔP / Δt) and the fluctuation level (ΔP) are both large, menu E for changing the charge limiter of power storage system 2 to increase is added to menu D for decreasing the SOC target value, and a sudden change occurs. A menu F is added to limit the output power PW of the wind power generation system 1 with time so that the output power PW increases with time. As a result, by increasing the output power PW of the wind power generation system 1 before the increase in the output power PW of the wind power generation system 1 due to the increase in wind, the output fluctuation due to the increase in wind is reduced. Increase range can be reduced. Further, by lowering the SOC of the power storage system 2 until the increase of the output power PW occurs, the chargeable capacity of the power storage system 2 when the output power PW of the wind power generation system 1 is increased is increased. After the increase in the output power PW of the wind power generation system 1 occurs, it is possible to extend the time during which the increased output power PW can be relaxed by charging the power storage system 2. Moreover, when the output power PW of the wind power generation system 1 is increased by increasing the wind by changing the charge limiter of the power storage system 2 to increase, the power system 5 is finally charged by charging the power storage system 2. Thus, it is possible to reduce the increase width of the output power PS.

  After the process S56 and the process S57, the windmill / storage battery control determining unit 36 determines whether or not the output power PS has been relaxed (output relaxation OK) (process S58). Yes), the changed control value is returned to the original (process S59), and the process returns to process S51. On the other hand, when it is not relaxed (No at Step S58), the process returns to Step S51.

  In the present embodiment, by performing at least one of the change of the SOC target value of the power storage system, the change of the charge / discharge limiter, and the output limitation of the wind power generation system, the fluctuation is determined in accordance with the sudden change of the predicted output power. Control within the range is possible. In addition, it is preferable to perform a series of operation | movement demonstrated in FIG.

  FIG. 6 is a characteristic diagram showing a wind speed fluctuation prediction method based on weather information of the weather observation apparatus in one embodiment of the present invention. With reference to FIG. 6, the method of estimating the wind speed of the wind farm 100 using the weather information measured with the weather observation apparatus 9 in one Embodiment of this invention is shown. As an example, a method for predicting fluctuations in wind speed occurring in the wind farm 100 using only the wind direction and wind speed information measured by the weather observation device 9 will be described.

As a prediction method, when the vector indicating the wind direction and wind speed currently measured by the weather observation device 9 is v, a virtual wind speed wavefront is defined in a direction perpendicular to v. It is assumed that the virtual wind speed wavefront propagates in the perpendicular direction at the wind speed vs. The virtual wind speed wavefront is extended and a position perpendicular to the wind farm 100 is defined as a point. From the definition of the virtual wind speed wavefront, the wind speed blowing at the current time T ₀ at the point a is a weather observation device. 9 is equal to the current wind speed vs. Therefore, at time T when the wind speed vs. blowing at the current time T ₀ at the point a reaches the wind farm 100, the distance between the weather observation device 9 and the wind farm 100 is L, the distance between the point a and the wind farm 100, and the wind farm. When the angle formed by a straight line between 100 and the meteorological observation device 9 is θ, it is expressed by (Equation 4).

(Equation 4) T = T ₀ + L cos θ / vs
From (Equation 4), it becomes possible to predict the fluctuation of the wind speed occurring at the time T in the wind farm 100.

  FIG. 7 is an explanatory diagram showing an example of prediction when the wind speed is suddenly decreased in the embodiment of the present invention. FIG. 7 shows an example of measured wind speed, wind direction, and predicted wind speed of the wind farm and the weather observation apparatus 9 according to the above method. It is predicted that a decrease in wind speed measured by the weather observation device 9 will occur in the wind farm 30 minutes ahead. It should be noted that the extent to which a sudden change in wind speed can be predicted varies depending on the installation position of the weather observation apparatus 9, the wind speed, and the wind direction, but can be predicted from about 10 minutes to about 3 hours ahead.

  FIG. 8 is a characteristic diagram showing an operation for changing the charge / discharge limit value of the power storage device according to the embodiment of the present invention. With reference to FIG. 8, the change of the charge / discharge limiter of power storage system 2 will be described. Usually, in the power storage system 2 using a chemical reaction such as a lead storage battery, a charge / discharge range limiter as shown in a normal charge / discharge map shown in FIG. 8 is provided. The charge / discharge range limiter depends on the SOC of the power storage system 2. This is determined in consideration of the life of the power storage system 2, etc. If the charge / discharge is always performed beyond the range of the charge / discharge limiter, the power storage system 2 rapidly deteriorates. However, the degradation of the power storage system 2 is minimized and the output power PW is controlled by increasing the charge / discharge output by expanding the limiter range only for a short time when the output power PW of the wind power generation system 1 changes suddenly. It is possible to maximize the fluctuation mitigation performance at the time of sudden change.

  In FIG. 8, the extent to which the charge / discharge range limiter indicated by the normal charge / discharge map is expanded when the sudden change in the output power PW is predicted is determined in consideration of the characteristics of the power storage system to be used. For example, in the case of a lead storage battery in which the discharge output limiter is 0.4C when the SOC is 50% in the normal charge / discharge map, when the sudden decrease in the output power PW is predicted, the discharge output limiter is set to 0.5C. Expand to. C is the C rate (= current value (A) / capacity (Ah)). When a battery with a capacity of 1 Ah is charged and discharged at 1 A, it is written as 1 C, and when charged and discharged at 0.5 A, it is written as 0.5 C. .

  FIG. 9 is a diagram illustrating a function of displaying the states of the wind power generation system, the power storage device, and the like according to an embodiment of the present invention. The display screen example illustrated in FIG. 9 is a management screen displayed on the display device 10. In FIG. 9, the upper part shows a measured value and a predicted value of the output power PW of the wind power generation system 1 of the wind farm 100, and has a function of displaying a time at which a sudden change in the output power PW is predicted. The lower part displays the current state and target value of the SOC, the state of the charge / discharge limit limiter, and the like as the state of the power storage device. Furthermore, as a measure of whether or not the fluctuation of the output power PS is within a predetermined range, a function of displaying the current fluctuation amount, a compliance rate that is an index indicating whether or not the fluctuation has fallen within a predetermined fluctuation range in a certain period, and the like Have Note that display items and the like can be variously changed according to the purpose.

  For example, referring to FIG. 9, the output power PW (see FIG. 1) of the wind power generation system 1 is predicted to suddenly decrease after 60 minutes. For this reason, the power storage device of the power storage system 2 is currently subject to the SOC target. The value is increased to 85%, and it can be seen that the charge / discharge limiter is “expanding”. For this reason, by increasing the discharge power of the charge / discharge power PB of the power storage system 2 60 minutes after the wind power is weakened and the output power PW of the wind power generation system 1 is reduced, it is possible to contribute to a reduction in the predicted output fluctuation.

  In the present embodiment, as described above, the power storage system 2 is configured by one or more power storage devices 211, 212,. The capacity of each power storage device has the same rating, and the case where all the SOCs of the power storage devices are set to the same value (for example, the SOC current value is 75% and the SOC target value is 80%) is an example shown in FIG. When the rated capacity of each power storage device is different and it is desired to change the SOC of the power storage device for each power storage device, the power storage system 2 should be allocated to each power storage device in consideration of the total amount of charge / discharge energy to be compensated What is necessary is just to calculate SOC.

  FIG. 10 is a characteristic diagram illustrating a method for controlling the wind power generation system and the power storage system with respect to the predicted output power fluctuation value according to the embodiment of the present invention. With reference to FIG. 10, a determination criterion for changing the discharge output limiter of the power storage system 2, the target value of the SOC, and the output of the wind power generation system 1 according to the predicted value of the output power PS will be described.

  In FIG. 10, the time until the predicted value of the output power PS reaches the lower limit value of the output power PS is denoted by Δt1. When Δt1 is short, even if the output of the wind power generation system 1 is limited with a slope in time, the output power PS may not be sufficiently limited before the output power PS suddenly decreases. In this case, the discharge output limiter of each power storage device of the power storage system 2 described in FIG. 8 is expanded.

  Further, if the predicted value of the output power PS is below the lower limit value of the output power PS and again exceeds the lower limit value of the output power PS, the value obtained by integrating the area of the range below the lower limit value of the output power PS is ΔSOC. , ΔSOC indicates energy that the power storage system 2 must discharge when it falls below the lower limit value of the output power PS. Even if ΔSOC is reduced from the SOC of the current power storage system, SOC depletion does not occur unless the SOC lower limit value of the power storage system is reached, so there is no need to change the SOC target value. Conversely, when ΔSOC is reduced from the current SOC and falls below the lower limit value of SOC, it is possible to prevent SOC depletion by changing the SOC target value in an increasing direction according to the lower amount. It becomes.

  Based on the wind speed measured by the weather observation device 9 provided outside the wind farm 100, the output fluctuation of the wind farm 100 can be suppressed within a predetermined range. In particular, it is effective because it can suppress short-cycle fluctuations of several minutes to about several tens of minutes that are effective from the viewpoint of power system control.

  In the embodiment described above, the wind farm 100 has been described as a renewable energy-based power generation system. However, the renewable energy utilization power generation system is not necessarily limited to the wind farm 100. For example, you may apply to a solar power generation device group and a wave power generation device group.

  For example, as a renewable energy-based power generation system, a solar power generation device group configured by one or more solar power generation devices, a power storage system 2 configured by one or more power storage devices, a solar power generation device group, and A renewable energy-use power generation system having a host controller 3 for controlling the power storage system, wherein the host controller 3 controls the fluctuation of the output power of the solar power generation device group within a predetermined outputable range. When a control command is issued to compensate for charging / discharging of the solar power generation system, the near future output power fluctuation of the photovoltaic power generation device group is predicted based on weather information, and whether the predicted output power deviates from the output possible range. If the determination departs from the output possible range, as a control command for the power storage system 2, the target value of the charge rate of the power storage system 2 and the power storage system At least one can change instruction of the charge-discharge power limit value systems out 2.

1 Wind power generation system (wind power generation equipment group)
2 Power storage system 3 Host controller (control device)
4 Transformer 5 Power system 6, 7 Wattmeter 8 Communication network 9 Meteorological observation device 10 Display device 11 SCADA
31 Wind speed fluctuation prediction means 32 Output fluctuation prediction means 33 Output fluctuation judgment means 34 Fluctuation mitigation control means 36 Windmill / storage battery control determination means (control means)
37 Windmill / Battery Condition Monitoring Unit 91 Meteorological Measurement Value Processing / Transmitting Device 100 Wind Farm (Renewable Energy Utilizing Power Generation System)
111, ..., 11n Wind turbine generator 211, ..., 21m

Claims (10)

Renewable having a wind power generator group composed of one or more wind power generators, a power storage system composed of one or more power storage devices, and a host controller for controlling the wind power generator group and the power storage system A method of controlling an energy-based power generation system,
The host controller is
In order to control the fluctuation of the output power of the wind power generator group to a predetermined output possible range, when instructing control to compensate by charging and discharging of the power storage system,
Predicts near-future output power fluctuations of the wind turbine generator group based on weather information, determines whether or not the predicted output power deviates from the output possible range, and deviates from the output possible range In this case, as a control command for the power storage system, a command to change at least one of a target value of the charging rate of the power storage system and a limit value of charge / discharge power of the power storage system is provided. Control method. The wind power generator is a variable pitch controllable wind power generator,
The host controller is
In addition to the control command for the power storage system, for the wind turbine generator,
The control method for a renewable energy-based power generation system according to claim 1, wherein when the output range is deviated, an instruction to change the output limit value by controlling the variable pitch is issued. Equipped with a weather observation device, at least one weather information among wind speed, wind direction, temperature, humidity, and pressure, the time when the weather information was measured, the latitude, longitude, and altitude position information of the location where the weather observation device is installed A method for controlling a power generation system using renewable energy according to claim 1, wherein data stored sequentially or for a certain period of time via a communication network are collectively transmitted to the host controller. The host controller is
Changes in the near future output power of the wind power generator group,
When the vector indicating the wind direction and wind speed, which is the weather information, is v, the wind power generation is assumed to be a virtual wind speed wavefront in a direction perpendicular to v, and the virtual wind speed wavefront propagates in the direction perpendicular to the wind speed. The control method for a renewable energy-based power generation system according to claim 1, wherein the prediction is based on a temporal change in wind speed fluctuation reaching the device group. The host controller is
Displaying the target value of the charge rate of the power storage system and the limit value of the charge / discharge power of the power storage system together with the actual value of the output power of the wind turbine generator group and the predicted value of the near future output power. The control method of the renewable energy utilization electric power generation system of Claim 1 characterized by these. The host controller is
When a command to change the target value of the charge rate of the power storage system is commanded as a control command for the power storage system, if the predicted output power is below the lower limit value of the output possible range, the target charge rate of the power storage system 2. The use of renewable energy according to claim 1, wherein when the predicted output power exceeds an upper limit value of the output possible range, the target value of the charge rate of the power storage system is decreased when the value is increased. Control method of power generation system. The host controller is
When the predicted output power falls below the lower limit value of the output possible range and again exceeds the lower limit value of the output power, the time t1 falls below the lower limit value and the time t2 rises above the lower limit value. Based on the output power, a value that is integrated over time is set as a capacity to be compensated, and the target value of the charging rate is changed in an increasing direction based on the capacity to be compensated. The control method of the renewable energy utilization power generation system of Claim 1. A solar power generation device group configured by one or more solar power generation devices, a power storage system configured by one or more power storage devices, and a host controller that controls the solar power generation device group and the power storage system A control method for a power generation system using renewable energy, comprising:
The host controller is
In order to control the fluctuation of the output power of the photovoltaic power generation device group to a predetermined output possible range, when giving a control command to compensate by charging and discharging of the power storage system,
Based on weather information, predict the near-future output power fluctuation of the group of solar power generation devices, determine whether the predicted output power deviates from the output possible range, and set the output possible range When deviating, as a control command for the power storage system, at least one of a target value of the charge rate of the power storage system and a limit value of charge / discharge power of the power storage system is commanded to be changed. How to control the system. A wave power generation device group constituted by one or more wave power generation devices, a power storage system constituted by one or more power storage devices, and a host controller for controlling the wave power generation device group and the power storage system; A control method for a power generation system using renewable energy, comprising:
The host controller is
In order to control the fluctuation of the output power of the wave power generation device group to a predetermined output possible range, in order to control to compensate by charging and discharging of the power storage system,
Predicting near-future output power fluctuations of the wave power generator group based on weather information, determining whether the predicted output power deviates from the output possible range, and determining the output possible range. When deviating, as a control command for the power storage system, at least one of a target value of the charge rate of the power storage system and a limit value of charge / discharge power of the power storage system is commanded to be changed. How to control the system. The wind power generation device group and the power storage system used in a renewable energy-based power generation system including a wind power generation device group configured by one or more wind power generation devices and a power storage system configured by one or more power storage devices A control device for controlling
The controller is
In order to control the fluctuation of the output power of the wind power generator group to a predetermined output possible range, when instructing control to compensate by charging and discharging of the power storage system,
Output fluctuation prediction means for predicting fluctuations in the near future output power of the wind turbine generator group based on weather information;
Output fluctuation determining means for determining whether or not the predicted output power deviates from the output possible range; and
Control means for instructing to change at least one of a target value of the charging rate of the power storage system and a limit value of charge / discharge power of the power storage system as a control command of the power storage system when deviating from the output possible range A control device characterized by that.

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