JP6338008B1 - Power stabilization system and control device - Google Patents

Abstract

Provided is a power stabilization system and a control device capable of causing a combined output of a variable power supply and a power storage device to follow a target combined output even when the output of the variable power supply is stopped. A power stabilization system (10) includes a chargeable / dischargeable power storage device (11), and a control device that controls a combined output of the output of the power storage device (11) and the output of a variable power supply (16). (13). The control device (13) calculates the maximum required charging power (ESmax) for causing the combined output to follow the target combined output until a predetermined time elapses after the output of the variable power supply (16) is stopped. Based on the maximum required charging power (ESmax), charging / discharging of the power storage device (11) is controlled. [Selection] Figure 1

Description

  The present invention relates to a power stabilization system and a control device.

  In recent years, the interconnection of variable power sources using renewable energy such as wind power generation and solar power generation to power systems has increased. However, since the output of the variable power supply changes from moment to moment, there is concern about the adverse effect on power quality associated with mass introduction. Therefore, output fluctuation mitigation control that compensates for fluctuations in the output of the power generation equipment by installing power storage devices such as storage batteries and flywheels at wind power plants and solar power plants, and charging and discharging control of the power storage devices. Proposed.

  For example, in the power stabilization system described in Patent Document 1, in order to reduce the influence on the system frequency when the variable power source is connected to the power system, the generated power generated by the variable power source is charged / discharged by the power storage device. It is smoothed by combining with electric power.

JP 2007-318883 A

  The output (generated power) of the variable power supply varies depending on factors such as the season, time of day, and weather conditions. However, if the operation of the variable power supply stops for some reason, the output of the variable power supply suddenly steps up to zero. It will decline. In this case, the load on the power storage device becomes excessive, so that the required charging power cannot be met, and there is a possibility that the operation of the power stabilization system may be hindered.

  In the power stabilization system, there is a case where control for prohibiting a decrease in the combined output of the variable power source and the power storage device is performed in a time zone where an increase in power demand is expected. When the operation (output) of the variable power supply is stopped during this reduction prohibition time period, the amount of electric power that the power storage device is responsible for increases dramatically, and the above technical problem is further highlighted.

  In the conventional power stabilization system, the target charging power of the power storage device may be set, but the calculation method of the target charging power is ambiguous and heuristic, for example, when the operation (output) of the variable power supply stops Until the predetermined time elapses, it has not been possible to guarantee that the power storage device and thus the power stabilization system will operate without trouble.

  The present invention has been made in view of such a point, and even when the output of the variable power supply is stopped, the power stabilization system and the control apparatus capable of causing the combined output of the variable power supply and the power storage device to follow the target combined output. Is one of the purposes.

The power stabilization system of the present embodiment includes a power storage device that can be charged and discharged, and a control device that controls a combined output of the output of the power storage device and the output of the variable power source. Until the predetermined time elapses from the time when the output of the variable power supply is stopped, the maximum required charging power for causing the combined output to follow the target combined output is calculated, based on the maximum required charging power, The charging / discharging of the power storage device is controlled, and the control device includes a current output of the variable power source, an output change rate setting value, a remaining time of a decrease allowable time of the combined output included in the predetermined time, and the predetermined The maximum required charging power is calculated based on the remaining time of the combined output reduction inhibition time included in the time.

The control device of the present embodiment is a control device that controls the combined output of the output of the power storage device and the output of the variable power source, and until the predetermined time elapses from the time when the output of the variable power source stops. The maximum required charging power for causing the combined output to follow the target combined output is calculated, the charging / discharging of the power storage device is controlled based on the maximum required charging power, the current output of the variable power supply, and the output change Based on the speed set value, the remaining time of the allowable reduction time of the combined output included in the predetermined time, and the remaining time of the combined output decrease prohibiting time included in the predetermined time, the maximum required charging power is calculated. It is characterized by computing .

  ADVANTAGE OF THE INVENTION According to this invention, even when the output of a fluctuation | variation power supply stops, the electric power stabilization system and control apparatus which can make the synthetic | combination output of a fluctuation | variation power supply and an electric power storage apparatus track a target synthetic | combination output can be provided.

It is a figure which shows the structural example of the electric power stabilization system of this embodiment. It is a figure which shows the reduction | restoration prohibition time of composite output, increase prohibition time, and increase / decrease prohibition time. It is a figure which shows the correspondence of each operation time slot | zone set by simulation, an output change rate, and a coefficient. It is a conceptual diagram which shows an example of the calculation of the maximum required charging power when the operation of the wind power generator is stopped at the start of the reduction prohibition time. An example of different functions for calculating the maximum required charging power used in the reduction allowable time and reduction prohibition time of the combined output is shown. It is a figure which shows the maximum required charging electric power when a driving | operation (output) of a wind power generator stops in the reduction | decrease permissible time (decrease prohibition preparation time), and a synthetic | combination output can be made into zero before the start of a reduction prohibition time. It is a figure which shows the maximum required charging electric power when a driving | operation (output) of a wind-power generator stops in reduction | decrease permissible time (decrease prohibition preparation time), and a synthetic | combination output cannot be made zero before the start of reduction prohibition time. It is a figure which shows the maximum required charging electric power when a driving | operation (output) of a wind power generator stops in the reduction prohibition time. It is a figure which shows the maximum required charging electric power when a driving | operation (output) of a wind power generator stops at the end of reduction | decrease prohibition time. It is a conceptual diagram which shows an example of the calculation of estimated generation electric power in case the driving | operation of a wind power generator stops at the time of the start of the reduction prohibition time. It is a figure which shows an example of an internal structure of an estimated electric power generation calculating part. It is a conceptual diagram which shows the relationship between the time average value of the output of a wind power generator in the start time of reduction | decrease prohibition time, and the power generation amount of a wind power generator in reduction | decrease prohibition time. It is a conceptual diagram which shows the relationship between the electric power generation predicted value of the wind power generator in the reduction prohibition time, and the electric power generation performance value corresponding to this. It is a block diagram which shows the calculation content by the control apparatus (The maximum required charging power calculating part, the estimated generated power calculating part, and the difference power calculating part). It is a figure which shows an example of the maximum required charging power in the 1st, 2nd case where the start time of reduction | restoration prohibition time is later than the present, and the present case.

  FIG. 1 shows a configuration example of a power stabilization system 10 of the present embodiment. The power stabilization system 10 includes a power storage device 11, a power converter 12, and a control device 13, and is connected to the power system 15 via a transformer 14. In the following description, it is assumed that the power stabilization system 10 performs output fluctuation compensation of a variable power source using renewable energy. In FIG. 1, a wind power generator 16 that is an example of a variable power source is connected to a power system 15 via a transformer 17. In addition, if it is the fluctuation | variation power supply linked | linked with the electric power grid | system 15, it may be not only a wind power generator 16 but a solar power generator, for example, and it is not limited to renewable energy. Further, the variable power source may be a power plant composed of a plurality of generators or a set of a plurality of power plants.

  The power storage device 11 includes, for example, a flywheel, a secondary battery, a capacitor, or the like. When the power storage device 11 is a flywheel, the AC power on the flywheel side and the AC power on the power system 15 side are converted in both directions. When the power storage device 11 is a secondary battery or a capacitor, the DC power on the secondary battery or capacitor side and the AC power on the power system 15 side are converted bidirectionally.

  The power converter 12 is connected to the power system 15 and the power storage device 11 based on the power converter output command value PO from the control device 13 (the direction in which power is discharged from the power storage device 11 is “positive”). The power PS is exchanged (that is, charging / discharging of the power storage device 11).

  The control device 13 includes a CPU and a memory (storage device such as a hard disk) (not shown), and executes various arithmetic processing and control processing described below. Various arithmetic processes and control processes performed by the control device 13 may be realized by hardware, or may be realized by a CPU reading and executing a predetermined application program stored in the storage device. Further, when realized by hardware, it may be controlled using a digital circuit such as a programmable controller, or may be realized by an analog control circuit such as an operational amplifier.

  The control device 13 controls the combined output of the output of the power storage device 11 and the output of the wind power generator (variable power source) 16. The control device 13 includes an active power detection unit 21, a stored power amount detection unit 22, a maximum required charge power calculation unit 23, an estimated generated power calculation unit 24, a differential power calculation unit 25, and a compensation power correction calculation unit 26. A smoothing filter 27, a limiter circuit 28, and a power converter control unit 29.

  The active power detection unit 21 detects the active power PG of the wind power generator 16 serving as the output of the variable power source based on the voltage and current value at the output terminal of the wind power generator 16. When the variable power source includes a plurality of generators / power stations, the active power detection unit 21 may detect the active power PG using the sum of the active powers detected by the feeders.

  The stored power amount detection unit 22 detects (calculates) the stored power amount ES of the power storage device 11 directly or indirectly. For example, when the power storage device 11 is configured by a flywheel, the stored power amount ES is detected (calculated) based on the rotational speed of the flywheel. Further, when the power storage device 11 is configured by a secondary battery or a capacitor, the terminal voltage and / or the terminal current is detected, and the stored power amount ES is detected (calculated) based on the detection result.

  When it is assumed that the operation (output) of the wind power generator 16 has stopped, the maximum required charging power calculation unit 23 has the power storage device 11 and the wind power generator 16 until the predetermined time elapses from the stop time. The maximum required charging power ESmax for making the combined output follow the target combined output is calculated. When the operation (output) of the wind power generator 16 stops, theoretically, the generated power of the wind power generator 16 suddenly decreases stepwise to zero, so that the loss is compensated by the discharge of the power storage device 11. There must be. The maximum required charging power ESmax is predetermined even under the worst condition, assuming the theoretical worst condition (the most severe condition) in which the power generated by the wind power generator 16 rapidly decreases to zero. The time is set to a value that can guarantee the operation of the wind power generator 16. The calculation of the maximum required charging power ESmax by the maximum required charging power calculation unit 23 will be described in detail later.

  When it is assumed that the operation (output) of the wind power generator 16 has stopped, the predicted generated power calculation unit 24 calculates the predicted generated power Eest of the wind power generator 16 during a predetermined time after the stop point. To do. Even when the operation (output) of the wind power generator 16 is stopped, the generated power of the wind power generator 16 does not actually decrease stepwise to zero, and the weather conditions and the characteristics of the power generation equipment (In the case of the wind power generator 16, the inertia of the rotating machine), the power generated by the wind power generator 16 gradually decreases to some extent. The expected generated power ESest is an estimate of the generated power that is generated when the generated power of the wind power generator 16 is moderately lowered for a predetermined time. The calculation of the predicted generated power Eest by the predicted generated power calculation unit 24 will be described in detail later.

  The difference power calculation unit 25 first calculates a required charge power (ESmax−ESest) that is a difference between the maximum required charge power ESmax calculated by the maximum required charge power calculation unit 23 and the expected generated power ESest calculated by the estimated generated power calculation unit 24. Calculate. The required charging power matches the stored power target value ESref of the power storage device 11. Further, the differential power calculator 25 subtracts the current stored power amount ES from the stored power target value ESref to calculate a corrected stored power amount ES ′.

  The compensation power correction calculation unit 26 calculates a compensation power correction signal PC such that the corrected stored power amount ES ′ becomes zero. For example, the compensation power correction signal PC is calculated by multiplying the corrected stored power amount ES ′ by a negative gain. If the stored power target value ESref exceeds the current stored power amount ES, the corrected stored power amount ES ′ takes a positive value. When the value is multiplied by a negative gain, the compensation power correction signal PC becomes a negative value. Then, an input signal of a smoothing filter 27, which will be described later, a combined output target value PA, and a power converter output command value PO become smaller, and the power storage device 11 charges power from the power system 15 via the power converter 12. Is encouraged. As a result, the stored power amount ES of the power storage device 11 increases, the stored power amount ES approaches the stored power target value ESref, and the corrected stored power amount ES ′ approaches zero.

  On the other hand, if the stored power target value ESref is lower than the current stored power amount ES, the corrected stored power amount ES ′ takes a negative value. When the value is multiplied by a negative gain, the compensation power correction signal PC becomes a positive value. Then, an input signal of a smoothing filter 27 described later, a combined output target value PA, and a power converter output command value PO become larger, and the power storage device 11 discharges power to the power system 15 via the power converter 12. Is encouraged. As a result, the stored power amount ES of the power storage device 11 decreases, the stored power amount ES approaches the stored power target value ESref, and the corrected stored power amount ES ′ approaches zero.

  If the corrected stored power amount ES ′ becomes zero, the stored power amount ES coincides with the stored power target value ESref, so that necessary charging power can be secured in the power storage device 11. In addition, although the required charging power is assumed to be equal to the stored power target value ESref and the method for realizing the control to match the stored power amount ES has been described, the stored power amount ES does not fall below the required charging power (ESmax-ESest). The control method may be used. In the configuration example shown in FIG. 1, the compensation power correction signal PC is added to the active power PG before the smoothing filter 27, but may be added after the smoothing filter 27.

  The smoothing filter 27 is a filter that removes a high frequency component from the added output of the active power PG from the wind power generator 16 and the compensation power correction signal PC from the compensation power correction calculation unit 26 and smoothes it. In FIG. 1, the smoothing filter 27 is configured by a first-order lag filter, but other methods may be applied to configure the smoothing filter. For example, a method using a moving average filter, a method of recombining in combination with a high-pass filter, or the like can be applied.

  The limiter circuit 28 includes a first limiter 41 that constitutes a short-period limiter that operates so as to keep the rate of change of the combined output within a predetermined range with respect to short-period fluctuations, and the combined output of the combined output with respect to long-period fluctuations. And a second limiter 42 that constitutes a long-period limiter that operates to keep the change rate within a predetermined width. The limiter circuit 28 may have either a configuration in which the output of the wind power generator 16 that is a variable power supply is controlled as an input or a configuration in which the combined output is controlled as an input. In the present embodiment, a configuration for controlling the output of the wind power generator 16 as an input will be described.

  The fluctuation component of the output of the wind power generator 16 or the combined output of the wind power generator 16 and the power storage device 11 includes a long-period fluctuation and a short-period fluctuation superimposed on the long-period fluctuation. The long-period fluctuation included in the output or combined output of the wind power generator 16 is, for example, an output fluctuation component of several tens of minutes to several hours, and the short-period fluctuation is an output fluctuation component of several tens of minutes. However, if there is a relationship in which short-period fluctuations are superimposed on long-period fluctuations, the fluctuation periods of long-period fluctuations and short-period fluctuations are not particularly limited. Analysis results (periodic characteristics) of the long-period fluctuations superimposed on the long-period fluctuations and the long-period fluctuations actually included in the output or combined output of the wind power generator 16, the management method by the power company, and the power company What is necessary is just to determine the assumption period of the long-term fluctuation | variation and the short-term fluctuation | variation which should be suppressed according to any one or arbitrary combinations of requirement specification and other conditions. For example, it is assumed that the long period fluctuation is 10 minutes to 5 hours and the short period fluctuation is 10 seconds to 5 minutes. Alternatively, it is assumed that the long period fluctuation is 30 minutes to 10 hours and the short period fluctuation is 1 minute to 20 minutes. Further, the fluctuation cycle of the long-period fluctuation and the short-period fluctuation need not be constant.

  The first limiter 41 and the second limiter 42 sample-hold the combined output target value or the combined output for sample times Δt1 and Δt2 for evaluating the short-period fluctuation and the long-period fluctuation of the combined output. In the present embodiment, the configuration in which the composite output target value is sampled and held is described. However, the present invention can also be applied to a configuration in which the composite output value is sampled and held. The first limiter 41 is given the previous combined output target value PA (S) from the first sample hold circuit 43 that samples and holds the combined output target value of the previous period Δt1 corresponding to the short period fluctuation. The sample hold period Δt1 is set to a sample time (for example, 10 seconds) suitable for evaluating short-period fluctuation. Note that the sample time for evaluating short-period fluctuations only needs to be shorter than the period of the fluctuation component to be suppressed, and is appropriately set in units of seconds or minutes, for example. The second limiter 42 is given the previous combined output target value PA (L) from the second sample hold circuit 44 that samples and holds the previous combined output target value for the period Δt2 corresponding to the long-period fluctuation. The sample hold period Δt2 is a sample time (for example, 10 minutes) suitable for evaluating long-period fluctuation. Note that the sample time for evaluating long-period fluctuations only needs to be shorter than the period of the fluctuation component to be suppressed, and is appropriately set, for example, in minutes or tens of minutes. Further, the sample hold periods Δt1 and Δt2 can be set to the same time.

  The first limiter 41 sets a value (= PA (S) + A1Δt1) obtained by adding a multiplication value obtained by multiplying the upper limit coefficient A1 by the sample hold time Δt1 to the combined output target value PA (S) before Δt1 to the upper limit level. Then, a value (= PA (S) + B1Δt1) obtained by multiplying the previous composite output target value PA (S) by the lower limit coefficient B1 multiplied by the sample hold time Δt1 is set as the lower limit level. With the coefficients A1 and B1, the change rate of the combined output corresponding to the short period fluctuation can be kept within a predetermined range.

  The second limiter 42 sets a value (= PA (L) + A2Δt2) obtained by adding a multiplication value obtained by multiplying the upper limit coefficient A2 by the sample hold time Δt2 to the combined output target value PA (L) that is Δt2 before the upper limit level. The value obtained by multiplying the previous composite output target value PA (L) and the lower limit coefficient B2 by the sample hold time Δt2 (= PA (L) + B2Δt2) is set as the lower limit level. With the coefficients A2 and B2, the change rate of the combined output corresponding to the long-period fluctuation can be kept within a predetermined range.

  The control device 13 prohibits the combined output at the connection point between the wind power generator 16 and the power stabilization system 10 from changing in the direction opposite to the increase / decrease in the power demand during a time period when the power demand greatly increases or decreases. The tendency for power demand to increase above a predetermined rate of change will be referred to as “significant increase”. A “decrease prohibited time” is set in which the combined output (combined output change rate) is prohibited from changing in a decreasing direction opposite to the power demand with respect to a time period in which the power demand increases significantly. In addition, the tendency for power demand to decrease by more than a predetermined rate of change will be referred to as “significant decrease”. It is set to “inhibition prohibition time” for prohibiting the combined output (combined output change rate) from changing in the increasing direction opposite to the power demand with respect to the time period in which the power demand is greatly reduced. In addition, the tendency for the power demand to increase and decrease beyond a predetermined rate of change will be referred to as “significant change”. The time zone during which the increase / decrease changes significantly is set to an “increase / decrease prohibition time” that prohibits the combined output (the combined output change rate) from changing in the decreasing direction and increasing direction. The time zone set in “Decrease Prohibition Time”, “Increase Prohibition Time” and “Increase / Decrease Prohibition Time” is not only from a fixed schedule (for example, fixed at 7:00 to 10:00), but also from an electric power company, etc. May be determined according to the external command, or may be determined according to the demand prediction result. In addition, it is good also as a system determined suitably according to various specifications and a request | requirement.

  The second limiter 42 is set to a lower limit that prevents the current combined output from falling below the previous combined output during the combined output decrease prohibition time, and the current combined output from the previous combined output during the combined output increase prohibited time. It is set to an upper limit that cannot be exceeded. Note that the second limiter 42 may set only one of a lower limit and an upper limit. In this example, the coefficient B2 for calculating the lower limit of the second limiter 42 is controlled to 0 during the decrease inhibition time. As a result, the lower limit of the combined output is limited to a lower limit level that does not fall below the previous combined output in the second limiter 42, so that the combined output target value is maintained at the combined output immediately before the decrease inhibition time. In addition, the coefficient A2 for calculating the upper limit of the second limiter 42 is controlled to 0 during the increase prohibition time. As a result, the upper limit of the combined output in the second limiter 42 is limited to an upper limit level that does not exceed the current combined output from the previous combined output, so that the combined output target value is maintained at the combined output immediately before the increase prohibition time. The Further, during the increase / decrease prohibition time, the coefficient A2 for calculating the upper limit of the second limiter 42 and the coefficient B2 for calculating the lower limit are controlled to zero. As a result, the upper limit and the lower limit of the combined output are limited in the second limiter 42, so that the combined output target value is maintained at the combined output immediately before the increase / decrease prohibition time.

  The power converter control unit 29 generates a power converter output command value PO according to the magnitude of the corrected compensation power ΔPG that is the difference between the combined output target value output from the limiter circuit 28 and the active power PG. The power converter 12 is controlled based on the converter output command value PO, and the power storage device 11 is charged and discharged with the power PS.

  With reference to FIGS. 2A to 2C, the combined output at the connection point of the wind power generator 16 and the power stabilization system 10 changes in the direction opposite to the increase / decrease direction of the power demand during a time period when the power demand increases or decreases. The operation for prohibiting this will be specifically described.

  FIG. 2A is a diagram showing the relationship between the upper limit (long cycle upper limit value) and lower limit (long cycle lower limit value) set for the second limiter 42 serving as a long cycle limiter and the output change rate. In the example shown in the figure, the time T11 to the time T12 correspond to a time zone in which power demand increases (a time zone in which a decrease in the combined output is restricted), and is set as a reduction prohibition time. The first limiter 41 controls the coefficients A1 and B1 so that the output change rate of the combined output is within ± 1% from the previous value (before Δt1), and the second limiter 42 controls the decrease prohibition time (and increase / decrease). Except for the prohibition time), the case where the coefficients A2 and B2 are controlled so that the output change rate is within ± 2% from the previous value (before Δt2) is illustrated. The lower limit (long cycle lower limit value) of the second limiter 42 is calculated such that the coefficient B2 is calculated so that the output change rate of the combined output becomes 0 during the decrease prohibition time (and increase / decrease prohibition time) (the composite output is the previous value). The upper limit (long-cycle upper limit value) of the second limiter 42 is within + 2% from the previous value (before Δt2) even if it is the decrease prohibition time (and increase / decrease prohibition time). Thus, the coefficient A2 is controlled. Specifically, the value obtained by multiplying the previous value PA (L) before Δt2 sampled and held by the second sample hold circuit 44 and the current coefficient B2 by the sample hold period Δt2 (= PA (L ) + B2Δt2) is set to the lower limit (long period lower limit value), but the decrease prohibition time (and increase / decrease prohibition time) is forcibly set to the coefficient B2 = 0. As a result, as shown in FIG. 2A, the decrease prohibition time (and increase / decrease prohibition time) is fixed to the previous value at the lower limit (long cycle lower limit value) of the second limiter 42, so that the combined output is Δt2 before Control is performed so as not to become smaller than the previous value PA (L).

  FIG. 2B is a diagram showing the relationship between the upper limit (long cycle upper limit value) and lower limit (long cycle lower limit value) set in the second limiter 42 during the increase prohibition time and the output change rate. In the example shown in the figure, time T21 to time T22 correspond to a time zone in which the power demand decreases (a time zone in which the increase in the combined output is restricted), and is set as an increase prohibition time. The first limiter 41 calculates the coefficients A1 and B1 so that the output change rate falls within ± 1% from the previous value (before Δt1), and the second limiter 42 calculates the increase prohibition time (and increase / decrease prohibition time). Other than the above, the case where the coefficients A2 and B2 are controlled so that the output change rate is within ± 2% from the previous value (before Δt2) is illustrated. The upper limit (long cycle upper limit value) of the second limiter 42 is calculated such that, during the increase prohibition time (and increase / decrease prohibition time), the coefficient A2 is calculated so that the rate of change of the composite output becomes zero (the composite output is set to the previous value The coefficient B2 is controlled so that the lower limit (long cycle lower limit value) of the second limiter 42 is within -2% from the previous value (before Δt2) even when the increase limit time is not allowed. Specifically, the value obtained by multiplying the previous value PA (L) before Δt2 sampled and held by the second sample hold circuit 44 and the current coefficient A2 by the sample hold period Δt2 (= PA (L ) + A2Δt2) is set to the upper limit (long period upper limit value), but the increase prohibition time (and increase / decrease prohibition time) is forcibly set to the coefficient A2 = 0. As a result, as shown in FIG. 2B, the increase prohibition time (and increase / decrease prohibition time) is fixed to the previous value at the upper limit (long cycle upper limit value) of the second limiter 42. Control is performed so as not to be larger than the previous value PA (L).

  FIG. 2C is a diagram showing the relationship between the upper limit (long cycle upper limit value) and lower limit (long cycle lower limit value) set in the second limiter 42 and the output change rate. In the example shown in FIG. However, it corresponds to a time zone (a time zone in which both reduction and increase of the combined output are regulated) in which the power demand greatly fluctuates (increases and decreases), and is set as an increase / decrease prohibited time. The second limiter 42 exemplifies a case where the coefficients A2 and B2 are controlled so that the output change rate is within ± 2% from the previous value (before Δt2) except for the increase / decrease prohibition time. The lower limit (long cycle lower limit value) and upper limit (long cycle upper limit value) of the second limiter 42 are controlled in combination with FIGS. 2A and 2B. That is, in the increase / decrease prohibition time, the lower limit (long cycle lower limit value) of the second limiter 42 is fixed to the previous value, so that the combined output is controlled so as not to become smaller than the previous value PA (L) before Δt2. In addition, since the upper limit (long period upper limit value) of the second limiter 42 is fixed to the previous value, the combined output is controlled so as not to become larger than the previous value PA (L) before Δt2.

  The first limiter 41 is given the previous combined output target value PA (S) from the first sample hold circuit 43, and the coefficient A1 so that the output change rate is within ± 1% from the previous value (before Δt1). , B1 is controlled.

  FIG. 3 shows the correspondence between each operation time zone set in the simulation, the output change rate, and the coefficients A2 and B2. The period from time 7:00 to time 10:00 is set as a decrease prohibition time, and the period from time 11:30 to time 13:30 is set as an increase / decrease prohibition time. Further, the period from 16:00 to 19:00 is set again as a decrease prohibition time, and the period from 20:00 to 23:00 is set as an increase prohibition time. In the second limiter 42 corresponding to the long period fluctuation, the coefficients A2 and B2 are controlled so that the output change rate other than the prohibition time is within ± 2%.

  The calculation of the maximum required charging power ESmax by the maximum required charging power calculation unit 23 will be described in detail with reference to FIGS.

  FIG. 4 is a conceptual diagram showing an example of the calculation of the maximum required charging power ESmax when the operation (output) of the wind power generator 16 is stopped at the start of the reduction prohibition time. In order to control the amount of discharge power of the power storage device 11 to the minimum when the power generated by the wind power generator 16 suddenly decreases stepwise to zero, the combined output of the power storage device 11 and the wind power generator 16 is used. Is preferably reduced as soon as possible. However, since the combined output of the power storage device 11 and the wind power generator 16 cannot be reduced during the reduction prohibition time, the power required for the reduction prohibition time (rectangular gray area surrounded by a one-dot chain line in FIG. 4) is used as power. It must be covered by the discharge power of the storage device 11. Further, even if the reduction prohibition time ends and shifts to the allowable reduction time, the combined output can be reduced only at a predetermined output change rate (for example, within 1% / min), so that the required power in the allowable reduction time ( The triangular gray area surrounded by the one-dot chain line in FIG. 4 must be covered by the discharge power of the power storage device 11. Therefore, the area of the trapezoidal gray region that is a combination of a rectangle and a triangle surrounded by a dashed line in FIG. 4 corresponds to the maximum required charging power ESmax. Even if this is the worst theoretical condition (the most severe condition) in which the electric power storage device 11 is charged with the maximum required charging power ESmax, the generated power of the wind power generator 16 suddenly drops to zero. The operation of the wind power generator 16 can be guaranteed for a predetermined time.

  By the way, the maximum necessary charging power ESmax includes the ratio of the allowable reduction time and the reduction prohibition time of the combined output until the predetermined time elapses after the operation (output) of the wind power generator 16 is stopped. It can vary depending on what is being done. In the following description, it is assumed that the “allowable reduction time of the composite output” includes “reduction prohibition preparation time (time before the start of the reduction prohibition time)” and “reduction prohibition release time (time after the end of the reduction prohibition time)”. (Both are common in the sense of allowing a decrease in the combined output). The control device 13 calculates the maximum required charging power ESmax based on the combined output reduction allowable time (reduction prohibition preparation time, reduction prohibition release time) and the stay time of the reduction prohibition time. In this specification, the allowable reduction time of composite output (reduction prohibition preparation time, reduction prohibition open time) and “stay time” of reduction prohibition time are the pure stay time of each time as written, and the start of each time It is used in a broad concept including time (start time) and end time (end time) and the remaining time when staying at each time.

  The control device 13 calculates the maximum required charging power ESmax by using different functions for the combined output reduction allowable time (reduction prohibition preparation time, reduction prohibition release time) and reduction prohibition time. FIG. 5 shows an example of different functions for calculating the maximum required charging power ESmax used in the combined output reduction allowable time and reduction prohibition time. As shown in FIG. 5, the function corresponding to the decrease allowable time (solid line) and the function corresponding to the decrease prohibition time (broken line) are linear functions having different slopes varying with time (corresponding to the decrease allowable time). The function corresponding to the decrease prohibition time is a straight line with a larger slope than the function). Note that the function shown in FIG. 5 is an example, and a quadratic function may be used instead of a linear function, and various design changes can be made to the specific form of the function.

  FIG. 6 shows the maximum required charging power ESmax when the operation (output) of the wind power generator 16 stops during the reduction allowable time (reduction prohibition preparation time) and the combined output can be zero before the start of the reduction prohibition time. Yes. Since the combined output must be changed so as to satisfy the short cycle fluctuation criterion (for example, the output change speed is within 1% / min) and the long cycle fluctuation criterion (decrease prohibition during the reduction prohibition time), the maximum required charging power ESmax Cannot be zero. In the example of FIG. 6, the required power (triangle gray area of the reduction prohibition preparation time) that is the combined output when the output is reduced at a predetermined output change speed corresponds to the maximum required charging power ESmax. Note that the larger the output when the wind power generator 16 is stopped, the larger the triangle in FIG. 6 becomes similar, so the maximum required charging power ESmax increases exponentially.

  FIG. 7 shows the maximum required charging power ESmax when the operation (output) of the wind power generator 16 is stopped during the reduction allowable time (decrease prohibition preparation time) and the combined output cannot be made zero before the start of the reduction prohibition time. Yes. In this case, after the composite output decreases at a predetermined output change rate using the reduction prohibition preparation time, the composite output needs to be constant during the reduction prohibition time. Utilizing this, the combined output further decreases at a predetermined output change rate. In the example of FIG. 7, the required power (a trapezoidal gray area of the reduction prohibition preparation time and a triangular gray area of the reduction prohibition release time) when the power is reduced at a predetermined output change rate and the composite output are kept constant. The sum of the required power (rectangular gray area of the decrease prohibition time) corresponds to the maximum required charging power ESmax.

  6 and 7, the control device 13 determines whether or not the combined output at the time of transition from the reduction allowable time (reduction prohibition preparation time) to the reduction prohibition time is greater than zero. If the composite output is smaller than zero, the composite output at the transition point is corrected to zero and the subsequent processing is continued (FIG. 6). If the composite output is larger than zero, the composite output at the transition point is used as it is. Subsequent processing can be continued (FIG. 7).

  FIG. 8 shows the maximum required charging power ESmax when the operation (output) of the wind power generator 16 is stopped during the reduction prohibition time. In this case, it is necessary to make the combined output constant during the reduction prohibition time, and the combined output decreases at a predetermined output change rate using the reduction prohibition release time after the end of the reduction prohibition time. In the example of FIG. 8, the required power when the composite output is maintained constant (rectangular gray area of the reduction prohibition time) and the required power when reduced at a predetermined output change rate (triangle gray of the reduction prohibition release time) Area) corresponds to the maximum required charging power ESmax. Further, the case where the operation (output) of the wind power generator 16 is stopped at the start of the reduction prohibition time corresponds to FIG. 4 described above, and the maximum required charging power ESmax becomes the largest.

  FIG. 9 shows the maximum required charging power ESmax when the operation (output) of the wind power generator 16 is stopped at the end of the reduction prohibition time (at the start of the reduction prohibition opening time). In this case, the combined output decreases at a predetermined output change speed by using the decrease prohibition release time after the end of the decrease prohibition time. In the example of FIG. 9, the required power (a gray area in the triangle of the reduction prohibition open time) when it is reduced at a predetermined output change speed corresponds to the maximum required charging power ESmax. In FIGS. 6 and 9, since the reduction prohibition time is not included in the predetermined time after the operation (output) of the wind power generator 16 is stopped, the combined output can be brought close to zero earliest (that is, the maximum required charging power ESmax). Is the smallest).

  As described above, the combined output of the wind power generator 16 and the power storage device 11 is restricted by the short period fluctuation and the long period fluctuation, and therefore the change rate and the fluctuation direction are limited. The control device 13 (maximum required charge power calculation unit 23) calculates the maximum required charge power ESmax assuming a case where the combined output approaches zero in the shortest time while satisfying the constraints of the short cycle fluctuation and the long cycle fluctuation. .

The specific calculation of the maximum required charging power ESmax can be executed by, for example, Expression (1). Note that when calculating the maximum required charging power ESmax, the efficiency of the power storage device 11 (efficiency during discharging) may be further considered, or the charging power amount corresponding to the charging power operation lower limit value may be considered. good. That is, the calculation formula for the maximum required charging power ESmax is not limited to the formula (1), and various design changes are possible.

  When the current output Pg ≦ rTp of the wind power generator 16 in the allowable reduction time (reduction prohibition preparation time), even if the generated power of the wind power generator 16 suddenly drops stepwise to zero, the reduction prohibited time The composite output can be reduced to zero before starting. Therefore, the maximum required charging power ESmax may be calculated by calculating the area of the triangle before or after the start of the reduction prohibition time, as shown in FIG. However, when the charging power of the power storage device 11 is discharged, a loss occurs until the connection point is reached. Therefore, the amount of power divided by the efficiency at the time of discharging may be secured. In addition, since charging power below the charging power operation lower limit value is not used for control in principle, a charging power amount corresponding to the charging power operation lower limit value may be added.

  On the other hand, when the current output Pg> rTp of the wind power generator 16 is within the allowable reduction time (reduction prohibition preparation time), the reduction prohibited time even if the generated power of the wind power generator 16 suddenly drops to zero. The combined output can only be reduced to Pg-rTp (> 0) by the start of the process. For this reason, the remaining time (stay time) of the reduction prohibition time is kept constant at its output (output at the start of the reduction prohibition time).

  In the reduction allowable time (reduction prohibition preparation time), the composite output must be maintained at Pg for the remaining time Tp. However, if the remaining time Tp = 0, as described above, the maximum required charging power ESmax can be calculated using Equation (1), as in the case of the current output Pg> rTp of the wind power generator 16. .

  With reference to FIGS. 10 to 13, the calculation of the predicted generated power Eest by the predicted generated power calculation unit 24 will be described in detail.

  FIG. 10 is a conceptual diagram illustrating an example of the calculation of the expected generated power E Est when the operation (output) of the wind power generator 16 is stopped at the start of the reduction prohibition time. Even when the operation (output) of the wind power generator 16 is stopped, the generated power of the wind power generator 16 does not actually decrease stepwise to zero, and the weather conditions and the characteristics of the power generation equipment (In the case of the wind power generator 16, the inertia of the rotating machine), the power generated by the wind power generator 16 gradually decreases to some extent. The expected generated power ESest is an estimate of the generated power that is generated when the generated power of the wind power generator 16 is moderately lowered for a predetermined time. In FIG. 10, the expected generated power ESest is drawn as the area of the portion surrounded by the broken line during the reduction prohibition time. In the present embodiment, the difference power obtained by subtracting the estimated generated power ESest from the maximum required charging power ESmax (maximum required charging power ESmax−estimated generated power ESest) is secured as “required charging power”. As a result, the capacity of the power storage device 11 (for example, a storage battery) is suppressed to a necessary minimum level to avoid an increase in cost associated with an increase in the size of the power storage device 11 (while improving economy), and a power stabilization system. 1 can be operated well.

  FIG. 11 shows an example of the internal configuration of the expected generated power calculation unit 24. The expected generated power calculation unit 24 includes a subtraction unit 24A, a multiplication unit 24B, a subtraction unit 24C, and a maximum value selection unit 24D. The subtracting unit 24A subtracts the output correction term α (unit: MW) of the wind power generator 16 from the output Pg (unit: MW) of the wind power generator 16 (Pg−α). The multiplication unit 24B obtains the first candidate power A (unit: MWh) by multiplying the subtraction result (Pg−α) of the subtraction unit 24A by the stay time KT (unit: h) of the reduction prohibition time. The subtracting unit 24C obtains the second candidate power B by subtracting the power generation amount prediction correction term β (unit: MWh) from the power generation prediction value Ef (unit: MWh) (Ef−β). The maximum value selection unit 24D selects the larger one of the first candidate power A and the second candidate power B as the expected generated power ETest.

  The first candidate power A has a meaning as an actual measurement value based on the current output Pg of the wind power generator 16. The first candidate power A can be expressed as A (MWh) = (Pg−α) × KT. This expression utilizes the fact that there is a strong correlation between the time average value of the power generation amount during the reduction prohibition time and the output Pg of the wind power generator 16 at the start of the reduction prohibition time.

  FIG. 12 is a conceptual diagram showing the relationship between the output (x) of the wind power generator 16 at the start of the reduction prohibition time and the time average value of the power generation amount (y) of the wind power generator 16 at the reduction prohibition time. FIG. 12 illustrates the case where the rated output of the power plant is 100 MW. Each plot in FIG. 12 shows an actual measurement value of the time average value of the output (x) and the power generation amount (y) of the wind power generator 16 in the past predetermined period. The output (x) of the wind power generator 16 does not change much and often maintains the same level for a predetermined time. Therefore, the time average value of the output (x) of the wind power generator 16 and the power generation amount (y) is often close to each other, and the plots are concentrated in the vicinity of the straight line y = x. Nevertheless, all plots are distributed with some variation around the straight line y = x. In the plot on the upper side of the straight line y = x, the time average value of the power generation amount y of the wind power generator 16 in the decrease prohibition time is larger than the output x of the wind power generator 16 at the start of the decrease prohibition time. On the other hand, the plot below the straight line y = x shows the time average value of the power generation amount y of the wind power generator 16 in the decrease prohibition time compared to the output x of the wind power generator 16 at the start of the decrease prohibition time. Is small.

  In this embodiment, even if it is a case where the output of the wind power generator 16 falls most, the electric power generation amount which can be anticipated reliably is calculated to estimated electric power generation ESest. In the example of FIG. 12, the plot (x, y) = (80, 30) that is farthest downward with respect to the straight line y = x among all the plots is above the straight line y = x−50. The expected generated power ESest can be calculated based on y = x−50. The output correction term α can be set to 50 MW, for example, but can be appropriately changed according to the wind power generator 16 and its environment (for example, actual values such as wind condition data).

  Assuming that the first candidate power A obtained by the above calculation method is the expected generated power ESest, even if the output of the wind power generator 16 suddenly decreases, the combined output can be guaranteed by the power storage device 11. Is possible. However, since the first candidate power A is calculated from limited information such as the output Pg of the wind power generator 16, there is a possibility that the power generation amount of the wind power generator 16 during the decrease prohibition time is underestimated or overestimated. .

  Therefore, for example, a power generation amount prediction technique using weather forecast data is installed in the power stabilization system 10, the second candidate power B is calculated using the power generation amount prediction value Ef, and this is calculated as the expected power generation power ESest. It is also possible to do. The weather forecast data is predicted by using a weather model in a wide space that is not limited to the location where the power generator 16 is installed, and the power generation prediction technology performs statistical learning using the weather forecast data. Therefore, it can be expected to accurately predict the power generation amount (expected power generation amount) of the wind power generator 16 during the reduction prohibition time.

  On the other hand, since the weather forecast data that can be obtained is updated in a cycle of several hours, the power generation amount predicted value Ef may be less accurate depending on the timing of calculation. Therefore, the power generation amount prediction correction term β for correcting the variation due to the prediction error is subtracted from the power generation amount prediction value Ef to calculate the second candidate power B that can be reliably estimated even if the prediction error varies. The second candidate power B can be expressed as B (MWh) = Ef−β.

The power generation amount prediction correction term β can be set by, for example, the following first to fourth stage processing methods.
First stage: A predicted power generation amount x is calculated based on weather forecast data and wind condition data at the installation site of the wind power generator 16.
Second stage: The actual value y is calculated by converting the wind condition data at the installation point of the wind power generator 16 into the power generation amount by a windmill power curve or the like.
Third stage: A combination of severe conditions is extracted from the calculated power generation amount predicted value x and the actual value y.
Fourth stage: A power generation amount prediction correction term β is determined according to severe conditions.

  FIG. 13 is a conceptual diagram showing the relationship between the predicted power generation amount (x) of the wind power generator 16 and the corresponding power generation amount actual value (y) during the reduction prohibition time. FIG. 13 illustrates a case where the rated output of the power plant is 100 MW, the reduction prohibition time is 3 hours, and the maximum power generation amount in the reduction prohibition time is 300 MWh. In FIG. 13, the predicted power generation value (x) of the wind power generator 16 and the actual power generation value (y) are often close to each other, and the plots are concentrated near the straight line y = x. Nevertheless, all plots are distributed with some variation around the straight line y = x. In the plot above the straight line y = x, the actual power generation amount value (y) is larger than the power generation amount prediction value (x) of the wind power generator 16, so the stored power of the power storage device 11 is insufficient. It tends to be difficult. On the other hand, in the plot below the straight line y = x, the actual power generation amount value (y) is smaller than the power generation amount prediction value (x) of the wind power generator 16, so the stored power of the power storage device 11 Tends to be short.

  In this embodiment, even if the power generation amount predicted value (x) of the wind power generator 16 is smaller than the power generation amount actual value (y), the power generation amount that can be reliably predicted is calculated as the expected power generation power ESest. In the example of FIG. 13, the plot (x, y) = (200, 80), which is farthest from the straight line y = x among all the plots, is above the straight line y = x−120. The expected generated power ESest can be calculated based on y = x−120. The output correction term β can be set to 120 MWh, for example, but can be appropriately changed based on wind condition data, weather forecast data, and the like.

  The larger one of the first candidate power A and the second candidate power B calculated as described above is adopted as the expected generated power ETest. Regardless of which of the first candidate electric power A and the second candidate electric power B is adopted, severe conditions based on the actual data are taken into consideration, so that the expected generated electric power ESest when the output of the wind power generator 16 suddenly decreases is accurately grasped. It becomes possible.

  FIG. 14 is a block diagram showing calculation contents by the control device 13 (maximum required charging power calculation unit 23, estimated generated power calculation unit 24, and differential power calculation unit 25).

  When the operation (output) of the wind power generator 16 is stopped, the maximum required charging power calculation unit 23 calculates the remaining time Tlong of the reduction prohibition time and the remaining time Tprep of the reduction prohibition preparation time based on the stop time t. The maximum required charging power calculation unit 23 uses the charging power correction function (FIG. 5) corresponding to the reduction prohibition time and the reduction prohibition preparation time, the remaining time Tlong of the reduction prohibition time, the remaining time Tprep of the reduction prohibition preparation time, and the wind power Based on the current output value Pg of the generator 16, the maximum required charging power ESmax is calculated. When it is assumed that the operation (output) of the wind power generator 16 has stopped, the predicted generated power calculation unit 24 calculates the predicted generated power Eest of the wind power generator 16 during a predetermined time after the stop point. To do. The differential power calculation unit 25 obtains the differential power (ESmax−ESest) obtained by subtracting the estimated generated power ESest from the maximum required charge power ESmax as the required charge power. The required charging power matches the stored power target value ESref of the power storage device 11. The differential power calculation unit 25 calculates a corrected stored power amount ES ′ that is a difference between the required charging power (storage power target value) ESref and the current charging power ES. Charging / discharging of the power storage device 11 is controlled based on the corrected stored power amount ES ′.

  As described above, in the present embodiment, the control device 13 is the maximum for causing the combined output to follow the target combined output until a predetermined time elapses after the output of the wind power generator (variable power supply) 16 is stopped. The required charging power ESmax is calculated, and charging / discharging of the power storage device 11 is controlled based on the maximum required charging power ESmax. In addition, the control device 13 calculates the expected generated power ESest of the wind power generator 16 from when the output of the wind power generator 16 is stopped until a predetermined time elapses, and the maximum required charging power ESmax and the expected generated power Based on the difference power (ESmax−ESest) of ESest, charging / discharging of the power storage device 11 is controlled. Thereby, even when the output of the wind power generator 16 stops, the combined output of the wind power generator 16 and the power storage device 11 can be made to follow the target combined output.

  In the above embodiment, the case where the maximum required charging power calculation unit 23 calculates the maximum required charging power ESmax using both the remaining time Tp of the reduction prohibition preparation time and the remaining time TL of the reduction prohibition time is exemplified. explained. However, the maximum required charging power calculation unit 23 can calculate the maximum required charging power ESmax using only one of the remaining time Tp of the reduction prohibition preparation time and the remaining time TL of the reduction prohibition time. That is, the maximum required charging power calculation unit 23 can calculate the maximum required charging power ESmax based on the stay time of the reduction prohibition preparation time or the reduction prohibition time.

  In the above-described embodiment, in the calculation of the maximum required charging power ESmax, the combined power that is the minimum amount of discharge power with respect to the theoretical worst condition that the generated power of the wind power generator 16 rapidly decreases stepwise to zero. Assume output control. Therefore, the remaining time Tp of the reduction prohibition preparation time and the remaining time TL of the reduction prohibition time are used to calculate how much the combined output can be reduced by the start time of the reduction prohibition time.

If the remaining time Tp of the reduction prohibition preparation time is unknown, it is impossible to grasp to what extent the combined output can be reduced. As a result, the amount of discharge power required to satisfy both the short cycle fluctuation and long cycle fluctuation constraints is increased. Here, “when the remaining time Tp of the decrease prohibition preparation time is unknown” can be rephrased as “when the start time (start time) of the decrease prohibition time is unknown”, and is classified into the following two cases. The
・ The length of the decrease prohibition time is known, but the start time (start time) of the decrease prohibition time is unknown.
・ The end time (end time) of the decrease prohibition time is known, but the start time (start time) of the decrease prohibition time is unknown.

  On the other hand, when the remaining time TL of the decrease prohibition time is unknown, for example, the start time (start time) of the decrease prohibition time is known, but the end time (end time) of the decrease prohibition time is unknown. Hereinafter, the control method (calculation method of the maximum required charging power ESmax) for each of these cases will be described.

<If the length of the reduction prohibition time is known, but the start time (start time) of the reduction prohibition time is unknown>
This corresponds to the case where the remaining time Tp of the reduction prohibition preparation time is unknown in the above-described equation (1). Assuming the theoretical worst condition that the generated power of the wind power generator 16 suddenly decreases stepwise to zero, the maximum required charging power ESmax becomes the largest because the remaining time of the reduction prohibition preparation time Tp = In the case of 0, that is, the start time (start time) of the decrease prohibition time is the current time. That is, the maximum required charging power ESmax can be calculated by the following equation (2) in which Tp = 0 in the above equation (1). Note that when calculating the maximum required charging power ESmax, the efficiency of the power storage device 11 (efficiency during discharging) may be further considered, or the charging power amount corresponding to the charging power operation lower limit value may be considered. good.

<When the end time (end time) of the decrease prohibition time is known but the start time (start time) of the decrease prohibition time is unknown>
This corresponds to the case where the total time of the remaining time Tp of the reduction prohibition preparation time and the remaining time TL of the reduction prohibition time (which is defined as TL ′) is determined, but the breakdown is unknown. Assuming the theoretical worst condition that the generated power of the wind power generator 16 suddenly decreases stepwise to zero, the maximum required charging power ESmax is largest when Tp = 0 and TL = TL ′. This is a case where the start time (start time) of the decrease prohibition time is now. That is, the maximum required charging power ESmax can be calculated by the following equation (3) where Tp = 0 and TL = TL ′ in the above equation (1). Note that when calculating the maximum required charging power ESmax, the efficiency of the power storage device 11 (efficiency during discharging) may be further considered, or the charging power amount corresponding to the charging power operation lower limit value may be considered. good.

  FIG. 15A, FIG. 15B, and FIG. 15C show the second case where the start time (start time) of the reduction prohibition time is later than the current time (the time until the reduction prohibition time is relatively long), which is later than the current time. In this case (time until the decrease prohibition time is relatively short), an example of the maximum required charging power ESmax in the present case is shown. 15A to 15C, the maximum required charging power ESmax is the largest in FIG. 15C. This is because the discharge power amount from the present to the start time (start time) of the decrease prohibition time (the trapezoid on the left side of FIGS. 15A and 15B) and the discharge power amount after the end of the decrease prohibition time (FIGS. 15A to 15C). This is because the total area with the triangle portion on the right side) is the same, and thus the area of the discharge power amount (rectangular portion in the middle of FIGS. 15A to 15C) in the reduction prohibition time is compared.

<If the start time (start time) of the decrease prohibition time is known, but the end time (end time) of the decrease prohibition time is unknown>
This corresponds to a case where the remaining time Tp of the reduction prohibition preparation time is determined, but it is only known that the remaining time TL of the reduction prohibition time is greater than zero. The worst condition in this case is that the remaining time TL = ∞ of the decrease prohibition time. If the discharge is continued for a long time in the reduction prohibition time, the charging power will eventually become insufficient, so the combined output must be made zero by the start time (start time) of the reduction prohibition time. In Equation (1) described above, when TL = ∞, the maximum required charging power ESmax can be calculated by Equation (4) below. However, since it is actually impossible to set the maximum required charging power ESmax = ∞, the upper limit value of the maximum required charging power ESmax calculated by Pg ² / 2r is employed in Equation (4).

  In the above embodiment, the case where the control device 13 controls charging / discharging of the power storage device 11 using the maximum required charging power ESmax has been described as an example, but instead of the maximum required charging power ESmax, the maximum required charging is performed. You may control charging / discharging of the electric power storage apparatus 11 using a rate (maximum required SOC). In this case, “expected SOC” is used instead of “expected generated power”. “Maximum required charging power” and “estimated generated power” in the claims are the absolute amount as stated in the wording, as well as “maximum required charging rate (maximum required SOC)” and “expected” which are charging percentages relative to full charging. Used in concepts including “SOC”.

  In addition, the output value of the variable power source (for example, the wind power generator 16) used for the calculation in the above embodiment may be a combined output value or a combined output target value. Since the output value of the variable power supply varies greatly, it may be better to use the combined output value as the equalized output value.

  Alternatively, the stored power target value ESref may be set using only the maximum required charging power ESmax without subtracting the estimated generated power ESest from the maximum required charging power ESmax (ESmax = ESref).

DESCRIPTION OF SYMBOLS 10 Electric power stabilization system 11 Electric power storage apparatus 12 Electric power converter 13 Control apparatus 14 Transformer 15 Electric power system 16 Wind generator (variable power supply)
17 Transformer 21 Active Power Detecting Unit 22 Stored Power Amount Detecting Unit 23 Maximum Required Charging Power Calculation Unit 24 Expected Generated Power Calculation Unit 24A Subtraction Unit 24B Multiplication Unit 24C Subtraction Unit 24D Maximum Value Selection Unit 25 Differential Power Calculation Unit 26 Compensation Power Correction Operation unit 27 Smoothing filter 28 Limiter circuit 29 Power converter control unit 41 First limiter 42 Second limiter 43 First sample hold circuit 44 Second sample hold circuit

Claims (7)

A power storage device capable of charging and discharging; and
A control device for controlling a combined output of the output of the power storage device and the output of the variable power source;
Have
The control device calculates a maximum required charging power for causing the combined output to follow a target combined output until a predetermined time elapses after the output of the variable power supply is stopped, and the maximum required charging power is calculated. Based on the control of the charging and discharging of the power storage device ,
The control device includes a current output of the variable power source, an output change speed setting value, a remaining time of a decrease allowable time of the combined output included in the predetermined time, and a decrease prohibition of the combined output included in the predetermined time. Calculating the maximum required charging power based on the remaining time of the time;
A power stabilization system characterized by that. The control device calculates the expected generated power of the variable power source from the time when the output of the variable power source stops until the predetermined time elapses, and the difference power between the maximum required charging power and the expected generated power Based on the control of the charge and discharge of the power storage device,
The power stabilization system according to claim 1. The control device calculates the maximum required charging power based on a staying time of the reduction allowable time and / or the reduction prohibition time,
The power stabilization system according to claim 1 or 2, wherein The control device calculates the maximum required charging power using a function different between the reduction allowable time and the reduction prohibition time,
The power stabilization system according to any one of claims 1 to 3, wherein The controller determines whether or not the combined output is greater than zero at the time of transition from the reduction allowable time to the reduction prohibition time;
The power stabilization system according to any one of claims 1 to 4, wherein The control device alleviates long-period fluctuations included in the output of the variable power source and / or the combined output and / or short-period fluctuations superimposed on the long-period fluctuations,
The power stabilization system according to any one of claims 1 to 5, wherein A control device that controls the combined output of the output of the power storage device and the output of the variable power source,
Until the predetermined time elapses from the time when the output of the variable power supply is stopped, the maximum required charging power for causing the combined output to follow the target combined output is calculated, based on the maximum required charging power, Control the charge and discharge of the power storage device ,
A current output of the variable power supply, an output change speed setting value, a remaining time of a decrease allowable time of the combined output included in the predetermined time, and a remaining time of a decrease prohibition time of the combined output included in the predetermined time; Based on the maximum required charging power,
A control device characterized by that.