JP2013027089A - Voltage control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique which can confine the entire bank of a power distribution system within a desired voltage range while suppressing equipment investment costs.SOLUTION: A voltage control apparatus 1 is connected at own end, or a connection point, to a second feeder 9 of the bank of a power distribution system including a first feeder 8 having a PV 5 connected thereto. The voltage control apparatus 1 comprises an SC 13 which can control reactive power at the own end, a solar radiation measuring instrument 10 which measures the amount of solar radiation in the vicinity of the own end, a setting data unit 11, and a reactive power control amount determination unit 12. The setting data unit 11 stores therein a correlating equation between the amount of solar radiation measured by the solar radiation measuring instrument 10 and the reactive power control amount of the SC 13 which can minimize a voltage deviation between the first and the second feeders 8 and 9. The reactive power control amount determination unit 12 determines the reactive power control amount of the SC 13 at the own end by using the correlating equation.

Description

  The present invention relates to a voltage control apparatus connected to a feeder included in a bank of a power distribution system at its own end.

  Current voltage regulators for distribution systems include transformers that perform voltage control by tap switching, such as LRT (Load Ratio control Transformer) and SVR (Step Voltage Regulator). And phase adjustment equipment that performs voltage control by reactive power control such as SC (Static Condenser), ShR (Shunt Reactor), SVC (Static Var Compensator) . Various techniques have been proposed for such a voltage regulator.

  For example, in the technique disclosed in Patent Document 1, phase adjusting equipment such as LRT, SC, and ShR is installed in combination. And after assuming the voltage fluctuation based on the power usage pattern of a typical load in advance, a control target voltage schedule for appropriately performing voltage fluctuation control is set, and based on the schedule, the LRT, the phase adjusting equipment, Perform coordinated control. According to such a technique, it is possible to suppress an unnecessary tap operation of the LRT caused by the single operation of the phase adjusting equipment, and it is possible to appropriately control the voltage of the distribution system.

  In the technique disclosed in Patent Document 2, a voltage control device using SC and ShR together is connected to a distribution line. Then, the three-phase average voltage value and three-phase moving average value of the measured voltage at its own end, which is the connection point (linkage point) to the distribution line of the voltage control device, is compared with the upper and lower limits of the control target voltage. In case of deviation, ShR is turned on / SC is opened so as to increase the reactive power load, and in case of voltage lower limit deviation, SC is turned on / ShR is opened so as to reduce reactive power load. According to such a technique, it is possible to control the voltage at its own end (hereinafter also referred to as “self-end voltage”) within the upper and lower limits of the control target voltage. In addition, by installing a voltage control device for each section of the distribution system, it is possible to appropriately control the system voltage of the entire distribution system.

JP 2007-189821 A Japanese Patent No. 3426961

  In distribution substations, the distribution system is managed and operated in units called banks composed of a plurality of feeders (distribution lines). Specifically, an LRT is installed in the bank sending part (connection point with the power transmission system), that is, the most upstream part of the bank, and appropriate voltage control is performed on a bank basis by LRT sending voltage control.

  As a control method of the LRT, a schedule method that assumes a power usage pattern of a load in a bank as described in Patent Document 1 described above, or an LDC that performs voltage control based on its own voltage value and passing current value ( The Line Drop Compensator (line voltage drop compensation) method is currently known.

  However, when a PV (Photovoltaic: photovoltaic power generation device) that generates power based on sunlight is connected to a feeder, a voltage deviation between the feeders in the same bank increases due to a voltage increase due to the generated power. When the voltage upper and lower limit deviations occur at the same time due to the increase in voltage deviation, the method of uniformly controlling the feeders by the single LRT unit as in the conventional method simultaneously sets the voltages of all the feeders in the bank to the appropriate voltage range. Can't fit inside.

  Further, as a countermeasure against this problem, it is conceivable to install a plurality of voltage regulators in the bank as in Patent Document 2, but there is a problem that the equipment cost is high because ShR is expensive.

  Therefore, the present invention has been made in view of the above-described problems, and provides a technique capable of keeping the entire bank of the power distribution system within a desired voltage range while suppressing the cost of capital investment. The purpose is to do.

  The voltage control device according to the present invention is a voltage control device that is connected to the second feeder of the bank of the power distribution system including the first feeder to which the photovoltaic power generation device is connected, at the end that is the connection point. The voltage control device includes a phase advance capacitor capable of controlling reactive power at the local end, a first measuring instrument that measures the amount of solar radiation near the local end, a set value data unit, and a reactive power control amount determining unit. With. The set value data part includes the amount of solar radiation measured by the first measuring instrument, and a reactive power control amount of the phase advance capacitor capable of minimizing a voltage deviation between the first and second feeders. Save the correlation. The reactive power control amount determination unit determines a reactive power control amount of the phase advance capacitor at the local end based on the amount of solar radiation measured by the first measuring instrument and the correlation.

  According to the present invention, the reactive power control amount of the phase advance capacitor at its own end is determined based on the amount of solar radiation measured by the first measuring instrument and the correlation between it and the reactive power control amount. Therefore, the voltage deviation between the first and second feeders can be minimized, and the entire bank of the distribution system can be kept within the appropriate voltage range. In addition, since the phase advance capacitor is less expensive than other voltage regulators, the cost of capital investment for realizing the above effects can be suppressed.

1 is a diagram illustrating a bank including a voltage control device according to Embodiment 1. FIG. 1 is a block diagram illustrating a configuration of a voltage control device according to a first embodiment. 6 is a diagram illustrating an example of settling value data according to Embodiment 1. FIG. 3 is a flowchart showing processing of the voltage control apparatus according to the first embodiment. 6 is a flowchart illustrating processing of the voltage control device according to the second embodiment. FIG. 6 is a block diagram illustrating a configuration of a voltage control device according to a third embodiment. 12 is a flowchart illustrating processing of the voltage control device according to the third embodiment. It is a figure which shows an example of the solar radiation amount preserve | saved at the solar radiation amount data part which concerns on Embodiment 3. FIG. 12 is a flowchart illustrating processing of the voltage control device according to the third embodiment. FIG. 10 is a diagram showing processing of the voltage control device according to the third embodiment. FIG. 6 is a block diagram illustrating a configuration of a voltage control device according to a fourth embodiment. It is a figure which shows an example of the setting value data which concern on Embodiment 4. 10 is a flowchart showing processing of the voltage control apparatus according to the fourth embodiment. FIG. 10 is a block diagram illustrating a configuration of a voltage control device according to a fifth embodiment. It is a figure which shows an example of the set value data concerning Embodiment 5. 10 is a flowchart illustrating processing of the voltage control device according to the fifth embodiment. 10 is a flowchart illustrating processing of the voltage control device according to the fifth embodiment. It is a figure which shows the structure of a related bank.

<Embodiment 1>
The voltage control apparatus according to the first embodiment of the present invention is provided in a bank which is a unit for management / operation of a distribution system. FIG. 18 is a diagram showing banks related to banks according to the present embodiment (hereinafter referred to as “related banks”). Before describing the voltage control apparatus according to the present embodiment, the related bank will be described below.

  The related bank includes a load-time tap switching transformer 4 (hereinafter “LRT4”), a photovoltaic power generation device 5 (hereinafter “PV5”), and a load 6. The LRT4 and PV5 have a first feeder 8. The LRT 4 and the load 6 are connected via a second feeder 9.

  The LRT 4 uniformly controls the voltage of the related bank, that is, the voltage in the first and second feeders 8 and 9 so as to fall within a predetermined appropriate voltage range. PV5 is a device that generates power by irradiation of sunlight, and the voltage of the first feeder 8 is increased by this power generation. The load 6 is a device that consumes power, and the voltage of the second feeder 9 drops due to this power consumption.

In the related bank as described above, the voltage deviation between the first feeder 8 and the second feeder 9 increases mainly due to the voltage increase due to the generated power of the PV 5. In this case, the control of the LRT 4 alone can only increase or decrease the voltage of the feeders 8 and 9 in the related bank uniformly. Therefore, these voltages are set within an appropriate voltage range (V _{min to} V indicated by a broken line in FIG. 18). within the _max range) at the same time.

  On the other hand, according to the voltage control device according to the present embodiment, it is possible to simultaneously hold the voltage of all the feeders in the bank within a desired voltage range (within an appropriate voltage range) while suppressing an increase in equipment cost. It has become. Hereinafter, the voltage control apparatus according to the present embodiment will be described. In the description of the voltage control apparatus according to the present embodiment, components similar to those described above are denoted by the same reference numerals and description thereof is omitted.

  FIG. 1 is a diagram showing a bank including a voltage control apparatus 1 according to Embodiment 1 of the present invention. As shown in FIG. 1, in the bank shown in FIG. 18, the voltage control device 1 is connected to the load 6 side of the second feeder 9 in the configuration shown in FIG. That is, the voltage control apparatus 1 according to the present embodiment has the second feeder 9 included in the bank of the power distribution system including the first feeder 8 to which the PV 5 is connected, and the own end that is the connection point (interconnection point). It is connected. Here, for simplicity of explanation, a bank consisting of only two first and second feeders 8 and 9 will be described, but the bank may be composed of two or more feeders.

  FIG. 2 is a block diagram showing a configuration of the voltage control apparatus 1 according to the present embodiment. As shown in FIG. 2, the voltage control apparatus 1 controls the solar radiation amount measuring instrument 10 that is the first measuring instrument, the set value data unit 11, the reactive power control amount determining unit 12, and the reactive power at its own end. And a possible phase advance capacitor 13 (hereinafter referred to as “SC13”).

  The solar radiation amount measuring device 10 measures the current solar radiation amount in the vicinity of its own end. For example, a solar irradiator is used as the solar radiation amount measuring instrument 10.

  The set value data unit 11 stores parameters (set value data) related to the control of the SC 13 and the like. The reactive power control amount determination unit 12 determines the reactive power control amount of the SC 13 based on the solar radiation amount measured by the solar radiation amount measuring device 10 and the parameters of the set value data unit 11, and the SC 13 Based on the amount, reactive power control at its own end is performed.

  FIG. 3 is a diagram illustrating an example of parameters (setting value data) stored in the setting value data unit 11. As shown in FIG. 3, the settling value data unit 11 according to the present embodiment is a correlation equation represented by parameters a and b, and the amount of solar radiation measured by the solar radiation amount measuring instrument 10 and the first amount In addition, a correlation equation with the reactive power control amount of the SC 13 that can minimize the voltage deviation between the second feeders 8 and 9 is stored. In the present embodiment, this correlation equation is expressed as the following equation (1).

Here, S [kW / m ² ] indicates the amount of solar radiation measured by the solar radiation amount measuring device 10, and ΔQ [kVar] is between the first and second feeders 8 and 9 when the amount of solar radiation is measured. The reactive power control amount of SC13 which can minimize a voltage deviation is shown. As shown in this equation (1), in this embodiment, the correlation equation between the solar radiation amount S and the reactive power control amount ΔQ is expressed by linear approximation. As shown in FIG. 3, not only the correlation equation (parameters a and b) but also the voltage control cycle t _s indicating the cycle in which the voltage control device 1 should perform voltage control is stored in the set value data unit 11. Has been.

Next, a method for calculating the correlation equation of the above equation (1) will be described. For example, before connecting (interconnecting) the voltage control device 1, the voltage distribution of each feeder of the bank to which the voltage control device 1 is connected and the amount of solar radiation in the vicinity of the planned point to which the voltage control device 1 is connected are previously set for a plurality of hours measure. The maximum for each insolation, (first feeder 8 in this case) feeders (here, the second feeder 9) and the maximum voltage maxV _f [kV] of the total feeder except the feeder connecting the voltage controller 1 A voltage average value maxV [kV] and a voltage V _s [kV] at a planned point where the voltage control device 1 is connected are obtained. Further, the reactance component X (induction) of the line impedance from the connection point (connection point of the LRT 4) to the upper system (transmission system) on the primary side of the bank to the connection point to the second feeder 9 of the voltage control device 1 Minute X) [kΩ] is also obtained. Based on these values, the reactive power control amount ΔQ [kVar] is estimated for each of the above-mentioned solar radiation amounts by the following equation (2).

  Then, linear approximation is performed based on the estimated reactive power control amount ΔQ and the amount of solar radiation S to obtain the correlation equation of the above equation (1), and the parameters a and b are stored in the settling value data unit 11. .

Here, the method of calculating the correlation equation (1) in consideration of the maximum average voltage value maxV [kV] has been described, but the present invention is not limited to this. For example, in estimating the reactive power control amount ΔQ for calculating the correlation expression of the equation (1), the voltage upper limit V _max [kV] or the voltage lower limit V in the system operation is used instead of the maximum voltage average value maxV [kV]. _Min [kV] may be taken into consideration.

That is, the maximum voltage average value maxV [kV] of all the feeders (here, the first feeder 8) excluding the feeder (here, the second feeder 9) connected to the voltage control device 1 of the above formula (2) is the upper limit of the operating voltage. If it exceeds the V _max, using the following equation (3) instead of the equation (2), may be estimated reactive power control amount ΔQ for calculating the correlation equation of the formula (1) . Or the minimum voltage average value minV [kV] of all the feeders (here 1st feeder 8) except the feeder (here 2nd feeder 9) which connects the voltage control apparatus 1 of the above Formula (2) is a minimum operating voltage. When V _min is not satisfied, the reactive power control amount ΔQ for calculating the correlation equation of equation (1) may be estimated using the following equation (4) instead of the above equation (2). Thus, by considering the operating voltage upper and lower limits, it is possible to suppress the occurrence of deviation of the voltage upper and lower limits due to the reactive power control of the voltage control device 1.

  In the above description, the correlation formula between the solar radiation amount S and the reactive power control amount ΔQ is calculated. However, as long as these correlations can be shown, the order of the correlation formula is not particularly limited and is not a correlation formula. It may be a correlation table or the like.

FIG. 4 is a flowchart showing an example of the overall processing of the voltage control apparatus 1 according to the present embodiment. Hereinafter, the overall processing procedure of the voltage control apparatus 1 will be described with reference to FIG. First, the voltage control device 1 is activated in accordance stored in the setting value data unit 11 Voltage control cycle t _s.

In step S1, the solar radiation amount measuring device 10 measures the current solar radiation amount S [kW / m ² ] in the vicinity of its own end, and the reactive power control amount determining unit 12 receives the current solar radiation amount S from the solar radiation amount measuring device 10. Obtain [kW / m ² ]. In addition, the reactive power control amount determination unit 12 acquires the correlation equation of the above equation (1) from the set value data unit 11.

In step S2, the reactive power control amount determination unit 12 performs reactive power control of the SC 13 at its own end based on the acquired current solar radiation amount S [kW / m ² ] and the correlation equation of the above equation (1). Determine the amount. Here, the reactive power control amount determination unit 12 substitutes the current solar radiation amount S [kW / m ² ] acquired in step S1 into the above equation (1), and the reactive power control amount ΔQ [ kVar] is calculated.

In step S3, in accordance with the determined reactive power control amount ΔQ [kVar], the reactive power control at its own end is performed in SC13. In the present embodiment, when the current reactive power control amount of SC 13 is detected as ΔQ _now by a detector (not shown), when ΔQ> ΔQ _now , SC 13 is input by an amount corresponding to ΔQ−ΔQ _now , When ΔQ <ΔQ _now , the SC 13 is opened by an amount corresponding to ΔQ−ΔQ _now . When ΔQ = ΔQ _now , the current state of the SC 13 is maintained. Note that the SC 13 can perform fine reactive power control by using a multi-stage phase advance capacitor having a small reactive power control amount instead of a single phase advance capacitor. The reactive power at its own end is controlled by turning on / off the SC 13 as in step S3.

The above will be described with reference to the state shown in FIG. 1. In the process of step S2, SC13 is performed so that the voltage of the second feeder 9 becomes as close as possible to the voltage of the first feeder 8 increased by PV5. The reactive power control amount ΔQ is estimated. Then, in the process of step S3, the voltage of the second feeder 9 is controlled based on the reactive power control amount ΔQ, so that the first and second feeders 8 and 9 as shown in the lower side of FIG. The voltage deviation between them is minimized. As a result, the LRT 4 can simultaneously hold the voltages of the first and second feeders 8 and 9 within the appropriate voltage range (the range of V _{min to} V _max indicated by the broken line in FIG. 1).

  Here, the case where the voltage deviation between the first and second feeders 8 and 9 is minimized by the reactive power control amount of the SC 13 obtained by the correlation equation (the reactive power control amount of the SC 13 according to the correlation equation). explained. However, the reactive power control amount of the SC 13 related to the correlation equation is not limited to the one that is strictly minimized as long as the voltage deviation between the first and second feeders 8 and 9 can be minimized. .

  As described above, according to the voltage control apparatus 1 according to the present embodiment, on the basis of the solar radiation amount measured by the solar radiation amount measuring instrument 10 and the correlation equation between it and the reactive power control amount ΔQ, The reactive power control amount ΔQ of the SC 13 is determined. Therefore, the voltage deviation between the first and second feeders 8 and 9 can be minimized. Therefore, the entire bank of the power distribution system can be within the appropriate voltage range. Moreover, since SC13, ie, a phase advance capacitor, is cheaper than other voltage regulators such as ShR (shunt reactor), the cost of capital investment for realizing the above effects can be suppressed. In addition, by measuring the amount of solar radiation, it is possible to cope with the generated power of PV5 that is influenced by the weather conditions, and accurate voltage control can be expected.

  In the above, in order to simplify the description, the bank including only the two first and second feeders 8 and 9 has been described. However, when a bank is composed of two or more feeders and a plurality of PV5s are connected to a plurality of feeders, the banks are reduced to one PV5 connected to the first feeder 8. For example, the above description may be performed.

<Embodiment 2>
In the first embodiment, the correlation equation of the above equation (1) is estimated from the measurement data such as the solar radiation amount S and the voltage distribution. However, enormous measurement data is required to improve the accuracy of the correlation equation. Moreover, it is preferable that the influence of the local solar radiation amount change in the solar radiation amount measuring instrument 10 by a cloud, a bird, etc. contained in measurement data is suppressed.

  Therefore, in the voltage control apparatus 1 according to the second embodiment of the present invention, the correlation equation of the above equation (1) can be calculated without using the measurement data of the first embodiment. Hereinafter, the voltage control apparatus 1 according to the present embodiment will be described. Hereinafter, the block configuration of the voltage control apparatus 1 according to the present embodiment is the same as that of the first embodiment. However, here, it is assumed that the bank is composed of two or more feeders and includes a plurality of PV5.

  FIG. 5 is a flowchart showing a calculation process of a correlation equation between the solar radiation amount S and the reactive power control amount ΔQ of the SC 13 in the present embodiment. Hereinafter, the calculation processing procedure will be described with reference to FIG.

  First, in step S11, a relational expression between PV5 generated power that becomes a voltage increase factor and the amount of solar radiation is obtained. In order to do this, first, an amount of voltage increase for each feeder caused by the generated power of PV5 is estimated.

Specifically, PV5 rated output (rated capacity) C [kW] is JIS C8918, AM (Air Mass) = 1.5, solar radiation = 1 [kW / m ² ], solar cell It is defined as the power generated by PV5 under the condition of module temperature = 25 [° C.]. Therefore, ignoring AM and the solar cell module temperature, when the amount of solar radiation is S [kW / m ² ], the ideal generated power [kW] is expressed by the following equation (5).

  However, the actual generated power [kW] of PV5 is usually smaller than the ideal generated power [kW], and is expressed by the following equation (6).

  Here, α is a numerical value of 1 or less, and is a value determined by various factors such as the solar cell module temperature, the AM value, and loss due to conversion from DC power to AC power. Hereinafter, α is referred to as a correction coefficient. For example, in the case of a crystalline solar cell, the ratio of actual generated power to ideal generated power is said to be approximately 0.8. Therefore, in this case, the value described on the left may be adopted as the correction coefficient α.

  The correction coefficient α may be set for each PV5 device manufacturer, or may be set to a value obtained by actually measuring the amount of solar radiation and generated power. Further, although the correction coefficient α may be set individually for each PV 5 in the bank, it is very time-consuming and is not realistic considering the operational aspect. Therefore, in the present embodiment, the correction coefficient α is uniform regardless of PV5. Similarly, in consideration of operational aspects, a plurality of PV5s in the feeder may be contracted and handled as one. In the present embodiment, it is assumed that PV5 in the same bank has a uniform amount of solar radiation S.

In this case, the solar radiation amount measured by the solar radiation amount measuring instrument 10 is N (≧ 2) PV5s connected (connected) to the i-th (i = 1, 2,...) Feeder among the plurality of feeders. When the same amount of solar radiation as S [kW / m ² ] is received, the power estimated to be generated by the PV 5 as a whole is expressed as the following equation (7) in consideration of the above equation (6). In the following formula (7), C _j [kW] is a rated output of the j (j = 1 to N) -th PV5 connected to the i-th feeder.

Based on this, the resistance of the line impedance from the connection point to the upper system of the bank to the connection point with the i-th feeder of PV5, and the solar radiation amount S [kW / m ² ] based on the electric power of the equation (7) that is estimated to generate power when receiving the same amount of solar radiation as in the following equation (8), the voltage increase ΔV _i [kV] in the i-th feeder is calculated for each feeder by the following equation (8): A simple estimation. In the following equation (8), R _j [kΩ] is a resistance component of the line impedance of the j (j = 1 to N) -th PV5 with respect to the connection point to the upper system of the bank, and V _base [kV] is a reference system voltage.

From the above equation (8), the voltage increase ΔV _i [kV] of each feeder is estimated. From this equation (8), the voltage increase ΔV _s [kV] at the feeder to which the voltage control device 1 is connected is also estimated.

Thereafter, in step S12, an average value ΔV _aver [kV] of the voltage increase excluding the voltage increase ΔV _s [kV] of the feeder to which the voltage control apparatus 1 is connected is calculated from the following equation (9).

In other words, in the configuration reduced to the first and second feeders 8 and 9 as in the first embodiment, the voltage of the first feeder 8 to which the PV 5 is connected in steps S11 and S12. _That is, ΔV _aver [kV] corresponding to the increase and ΔV _s [kV] corresponding to the voltage increase of the second feeder 9 to which the voltage control device 1 is connected are estimated. Hereinafter, in order to simplify the description, the reduced configuration will be described.

In step S13, based on these voltage rises ΔV _aver and ΔV _s and the reactance amount X [kΩ] of the line impedance from the connection point to the upper system to the connection point to the second feeder 9 of the voltage control device 1. Thus, the reactive power control amount ΔQ [kVar] related to the correlation equation of the above equation (1) is approximately obtained by the following equation (10).

  Steps S11 to 13 using the above equations (8) to (10) are performed for various values of the solar radiation amount S, and the reactive power control amount ΔQ is obtained for the various values of the solar radiation amount S. .

  In step S14, based on the solar radiation amount S and the reactive power control amount ΔQ obtained as described above, the correlation equation of the above equation (1), that is, the parameters a and b are obtained. In step S15, the obtained correlation equation (parameters a and b) is stored in the set value data unit 11.

  According to the voltage control apparatus 1 according to the present embodiment as described above, measurement data such as an enormous amount of solar radiation S and a voltage distribution for calculating a correlation formula between the amount of solar radiation S and the reactive power control amount ΔQ is unnecessary. It becomes. Moreover, the influence of the local solar radiation amount change in the solar radiation amount measuring device 10 by a cloud, a bird, etc. contained in measurement data can be suppressed.

<Embodiment 3>
In the above-described embodiment, for example, when a cloud happens to occur only in the vicinity of the voltage control device 1, the measured solar radiation amount S of the solar radiation amount measuring device 10 decreases locally, and therefore the first and second feeders 8. , 9, there is a possibility that the reactive power control amount ΔQ for minimizing the voltage deviation cannot be accurately determined. Therefore, in Embodiment 3 of the present invention, it is possible to improve the accuracy of determining the reactive power control amount even when the measured solar radiation amount S of the solar radiation amount measuring device 10 is locally changed. .

  FIG. 6 is a block diagram showing a configuration of the voltage control apparatus 1 according to the present embodiment. In the description of the voltage control apparatus 1 according to the present embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. As shown in FIG. 6, the voltage control apparatus 1 according to the present embodiment is obtained by adding a solar radiation amount data unit 14 and an average solar radiation amount estimation unit 15 to the configuration of the first embodiment. Yes.

  FIG. 7 is a flowchart showing an example of the overall processing of the voltage control apparatus 1 according to the present embodiment. Hereinafter, the overall processing procedure of the voltage control apparatus 1 will be described with reference to FIG.

  First, in step S21, the solar radiation amount measuring device 10 measures the solar radiation amount, and the solar radiation amount data unit 14 stores the solar radiation amount measured by the solar radiation amount measuring device 10 at a plurality of time points. In FIG. 8, an example of the solar radiation amount preserve | saved at the solar radiation amount data part 14 is shown.

  In step S <b> 22, the average solar radiation amount estimating unit 15 estimates the average solar radiation amount by averaging the solar radiation amounts within the past period (predetermined period) stored in the solar radiation amount data unit 14. The average solar radiation amount here corresponds to the average value Savr of the measured solar radiation amount S in the past period or the measured solar radiation amount S most recently measured by the solar radiation amount measuring device 10. The estimation process in step S22 will be described in detail later.

  In step S23, the reactive power control amount determining unit 12 acquires the average solar radiation amount from the average solar radiation amount estimating unit 15, and the average solar radiation amount S in the correlation equation of the above equation (1) from the set value data unit 11. Obtain a correlation formula instead of the amount of solar radiation.

  In step S24, the reactive power control amount determination unit 12 determines the reactive power control amount of the SC 13 at its own end based on the acquired average solar radiation amount and the correlation equation. That is, in this embodiment, instead of the solar radiation amount S measured by the solar radiation amount measuring device 10 in the first embodiment, the average solar radiation amount estimated by the average solar radiation amount estimating unit 15 is used.

  In step S25, in the same manner as in step S3 of the first embodiment, in accordance with the determined reactive power control amount ΔQ [kVar], reactive power control at its own end is performed in SC13.

  FIG. 9 is an example of a flowchart showing in detail the process of step S22 performed by the average solar radiation amount estimation unit 15. Hereinafter, the estimation process in step S22 will be described in detail.

  First, in step S31, the average solar radiation amount estimating unit 15 performs a plurality of measurements within a past period (for example, a period between the current time and a time one minute later) from the solar radiation amount data unit 14. The amount of solar radiation S is acquired.

In step S32, the average solar radiation amount estimating unit 15 calculates a solar radiation variation amount ΔSi indicating a variation amount of the solar radiation amount of each time section based on the acquired plurality of measured solar radiation amounts S [kW / m ² ]. . Then, the average solar radiation amount estimating unit 15 calculates the solar radiation variation average ΔSavr, which is the average of the solar radiation variations ΔSi within the above-described past period, and the solar radiation variation standard deviation ΔSσ, which is a standard deviation of the solar radiation variation ΔSi. Ask.

In step S33, the average solar radiation amount estimation unit 15 sets the average solar radiation variation amount ΔSavr as the reference solar radiation variation amount shown in FIG. 10, and sets a range of ΔSavr−ΔSσ and not more than ΔSavr + ΔSσ as a dead zone shown in FIG. . And the average solar radiation amount estimation part 15 is the variation | change_quantity of the measurement solar radiation amount S (t) which the solar radiation amount measuring device 10 measured most recently, and the measurement solar radiation amount S (t-1) measured immediately before it. The most recent solar radiation change amount ΔS _now is calculated.

In step S34, the average solar radiation amount estimation unit 15 determines whether the latest solar radiation change amount ΔS _now is smaller than the lower limit of the dead zone (ΔSavr−ΔSσ). If it is determined that it is small (ΔS _now is out of the dead zone), the process proceeds to step S36, and if not, the process proceeds to step S35.

In step S35, the average solar radiation amount estimation unit 15 determines whether or not the latest solar radiation change amount ΔS _now is larger than the upper limit (ΔSavr + ΔSσ) of the dead zone. If it is determined that it is large (ΔS _now is out of the dead zone), the process proceeds to step S36, and if not, the process proceeds to step S37.

In step S36, which is performed when the most recent change in the solar radiation amount S is such that ΔS _now deviates from the dead zone, the average solar radiation amount estimation unit 15 performs the above-described average value of the measured solar radiation amount S in the past period. Savr is calculated and used as the average solar radiation. On the other hand, in step S37 performed when the latest (current) change in the amount of solar radiation S is slow, the average solar radiation amount estimation unit 15 employs the latest measured solar radiation amount S _now as the average solar radiation amount.

As mentioned above, although the example of the process which the average solar radiation amount estimation part 15 estimates an average solar radiation amount was demonstrated, you may perform the following another processes. For example, when the most recent solar radiation change amount ΔS _now deviates from the dead zone, the average solar radiation amount estimation unit 15 fixes the values of ΔSavr and ΔSσ, and as shown in the hatched portion in FIG. The solar radiation change amount integration amount ΔSp [ms · kW / m ² ], which is an integration amount relating to, is calculated. When the solar radiation change amount integration amount ΔSp exceeds the set threshold value, the average solar radiation amount estimation unit 15 employs the average value Savr of the measured solar radiation amount S in the past period as the average solar radiation amount. On the other hand, when the solar radiation change amount integration amount ΔSp is equal to or less than the set threshold value, the average solar radiation amount estimation unit 15 employs the latest measured solar radiation amount S as the average solar radiation amount. When the latest solar radiation change amount ΔS _now returns to the dead zone range, ΔSavr and ΔSσ are calculated again from the next time.

  Note that the set threshold value used in this process may be stored in the set value data unit 11. Next, an example of a method for determining the setting threshold will be described.

For example, when the size of the cloud over the vicinity of the voltage control device 1 is assumed to be 100 [m] wide and the wind speed is 10 [m / s] (average wind speed), it passes through the vicinity of the voltage control device 1. The time can be estimated empirically to be about 10 [s]. Therefore, ΔSσ × 10000 [ms · kW / m ² ] may be determined as the setting threshold value. Note that the setting threshold value determination method described here is an example, and other determination methods may be adopted.

As the estimation of the average solar radiation amount, the following processing may be performed instead of the above processing. For example, when the latest solar radiation change amount ΔS _now deviates from the dead zone, the settling value data unit 11 uses the estimated cloud transit time 10 [s] (= 10000 [ms]) as the operation time tm [ms] in the same manner as described above. Set (save) to. However, when the operation time tm> 0 already (when the dead zone deviates), the initial value has already been input, so the value of the operation time tm is not changed. During the operation time tm> 0, the difference in the solar radiation amount measurement period is calculated from the operation time tm, and the average value of the measurement solar radiation amount S in the past period is adopted as the average solar radiation amount as described above. Then, when the operating time tm ≦ 0, ΔSavr and ΔSσ are calculated again from the next time.

  As another simple means, it is conceivable to always adopt the average value of the amount of solar radiation measured in the past organization as the average amount of solar radiation.

  According to the voltage control apparatus 1 according to the present embodiment as described above, based on the average solar radiation amount in which local changes are suppressed and the correlation equation of the above equation (1), A reactive power control amount ΔQ is determined. Therefore, since the local change which arises when the cloud happens to be in the vicinity of the voltage control apparatus 1 can be suppressed, it is possible to suppress the local change from affecting the measured solar radiation amount S. Therefore, the reactive power control amount of SC13 can be stabilized.

<Embodiment 4>
FIG. 11 is a block diagram showing a configuration of the voltage control apparatus 1 according to the fourth embodiment of the present invention. In the description of the voltage control apparatus 1 according to the present embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. As FIG. 11 shows, the voltage control apparatus 1 which concerns on this Embodiment generate | occur | produces electric power based on the sunlight irradiated in the voltage control apparatus 1 instead of the solar radiation amount measuring device 10 in an own apparatus. In addition, a PV 16 (hereinafter referred to as “own device PV 16”) that is a power generation measuring device that measures the power is provided.

  In the first embodiment, the reactive power control amount of the SC 13 is determined based on the solar radiation amount S measured by the solar radiation amount measuring instrument 10 and the correlation equation of the above equation (1). In the present embodiment, The reactive power control amount of the SC 13 is determined based on the power PG [kW] measured by the own device PV16 and the correlation equation of the following equation (11). The following equation (11) is the correlation between the power PG measured by the own device PV16 and the reactive power control amount of the SC 13 that can minimize the voltage deviation between the first and second feeders 8 and 9. This is a correlation formula in which the solar radiation amount S in the correlation formula of the above formula (1) is replaced with the power PG.

  As mentioned above, in this Embodiment, it replaces with the solar radiation amount measured with the solar radiation amount measuring device 10, and uses the electric power measured with the own apparatus PV16.

FIG. 12 is a diagram illustrating an example of parameters (setting value data) stored in the setting value data unit 11. With the change from the solar radiation amount S to the power PG, the settling value data unit 11 according to the present embodiment stores the parameters a ₁ and b ₁ of the above equation (11).

As for the specific calculation means of the above equation (11), actual measurement data may be collected and calculated in the same manner as in the example of the first embodiment, and the above equation (8) of the second embodiment may be calculated. Instead of the following equation (12), the calculation may be performed by performing the same procedure as in the second embodiment. In addition, C _self [kW] in the following formula (12) indicates the rated output of the own device PV16.

FIG. 13 is a flowchart illustrating an example of the overall processing of the voltage control apparatus 1 according to the present embodiment. Hereinafter, the overall processing procedure of the voltage control apparatus 1 will be described with reference to FIG. First, the voltage control device 1 is activated in accordance stored in the setting value data unit 11 Voltage control cycle t _s.

  In step S41, the own device PV16 measures the power PG [kW], and the reactive power control amount determination unit 12 acquires the power PG [kW] from the own device PV16. In addition, the reactive power control amount determination unit 12 acquires the correlation equation of the above equation (11) from the set value data unit 11.

  In step S42, the reactive power control amount determination unit 12 determines the reactive power control amount of the SC 13 at its own end based on the acquired power PG [kW] and the correlation equation of the above equation (11).

  In step S43, as in step S3, the reactive power control at its own end is performed in SC13 according to the determined reactive power control amount ΔQ [kVar].

  According to the voltage control apparatus 1 according to the present embodiment as described above, unlike the first to third embodiments, it is not necessary to estimate the generated power PG from the solar radiation amount S. Improvement in accuracy can be expected. Further, if the voltage control device 1 uses the power generated by the own device PV16, the power supply of the voltage control device 1 can be expected to be omitted.

<Embodiment 5>
In the first embodiment, the determination of the reactive power control amount in consideration of the upper and lower limits of the operating voltage is described by the above equations (3) and (4). However, since the past actual measurement data cannot always cover all the system states, there is a possibility that the voltage upper and lower limits may be deviated by the reactive power control of the voltage control device 1. Therefore, in the fifth embodiment of the present invention, the voltage at the local end when controlled by the reactive power control amount determined in the first embodiment is estimated, and the reactive power control amount of the SC 13 is based on the voltage or the like. It is possible to reduce the voltage from deviating from the upper and lower limits.

  FIG. 14 is a block diagram showing a configuration of voltage control apparatus 1 according to the fifth embodiment of the present invention. In the description of the voltage control apparatus 1 according to the present embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. As shown in FIG. 14, the voltage control apparatus 1 according to the present embodiment is obtained by adding a voltage measuring instrument 17 that is a second measuring instrument that measures the voltage at its own end to the configuration of the first embodiment. It has become. Here, the sensor PT is provided at its own end, and the voltage measuring device 17 measures the voltage at the sensor PT.

FIG. 15 is a diagram illustrating an example of parameters (setting value data) stored in the setting value data unit 11. As shown in this figure, the settling value data unit 11 according to the present embodiment includes a self-end voltage upper limit V _smax [kV] indicating the upper limit and the lower limit of the self-end voltage and the self-end in addition to the data so far. Self-device connection point reactance indicating the lower limit voltage V _smin [kV] and the reactance component X [kΩ] of the line impedance from the connection point to the upper system of the bank to the connection point to the second feeder 9 of the voltage control device 1 And saving.

FIG. 16 is a flowchart showing an example of the overall processing of the voltage control apparatus 1 according to the present embodiment. Hereinafter, the overall processing procedure of the voltage control apparatus 1 will be described with reference to FIG. First, the voltage control device 1 is activated in accordance stored in the setting value data unit 11 Voltage control cycle t _s.

In step S51, the reactive power control amount determination unit 12 obtains the current solar radiation amount S [kW / m ² ] from the solar radiation amount measuring instrument 10, and sets the set value data shown in FIG. 15 from the set value data unit 11. get. In addition, the voltage measuring instrument 17 measures the current voltage V _s at its own end (hereinafter also referred to as “current self-end voltage V _s ”), and the reactive power control amount determination unit 12 determines the voltage measuring instrument 17. The current self-end voltage V _s is obtained from

In step S52, the reactive power control amount determination unit 12 determines the reactive power control amount ΔQ of the SC 13 based on the current solar radiation amount S, the current self-end voltage V _s, and the set value data. The determination process in step S52 will be described in detail later.

  In step S53, as in step S3 of the first embodiment, the reactive power control at its own end is performed in SC13 in accordance with the determined reactive power control amount ΔQ [kVar].

  FIG. 17 is an example of a flowchart illustrating in detail the determination process in step S52 performed by the reactive power control amount determination unit 12. Hereinafter, the process of step S52 will be described in detail.

  First, in step S61, the reactive power control amount determination unit 12 determines the current solar radiation amount S measured by the solar radiation amount measuring instrument 10 and the correlation equation of the above equation (1), as in step S2 of the first embodiment. Based on, reactive power control amount ΔQ [kVar] is determined.

In step S62, the reactive power control amount determination unit 12 determines the reactive power control amount ΔQ [kVar], the reactance amount X [kΩ] included in the set value data, and the current self measured by the voltage measuring device 17. Based on the voltage V _s [kV], the voltage V _snew [kV] at the local end when the reactive power at the local end is controlled by the reactive power control amount ΔQ [kVar] described above is expressed by the following equation (13): ). The self-end voltage V _snew estimated here may be hereinafter _referred to as “estimated self-end voltage V _snew ”.

In steps S63 to S66 described below, the reactive power control amount determination unit 12 determines the estimated self-end voltage V _snew [kV] and the self-end voltage predetermined to the self-end voltage included in the set value data. Based on the upper limit V _smax [kV] and the own end voltage lower limit V _smin [kV], the reactive power control amount ΔQ of the SC 13 at the own end is determined.

In this embodiment, at step S63, the estimated local end voltage V _snew [kv] is the own terminal voltage upper limit V _smax [kV] or greater than, that deviates from the local end voltage limit V _smax [kV] It is determined whether or not. When it determines with having deviated, it progresses to step S64, the reactive power control amount (DELTA) Q of SC13 is corrected (decided) by following Formula (14), and a process is complete | finished. Otherwise, the process proceeds to step S65.

At step S65, it determines whether the estimated local end voltage V _snew [kv] is the own terminal voltage limit V _smin [kV] or smaller than, that is, deviating from the local end voltage limit V _smin [kV]. When it determines with having deviated, it progresses to step S66, the reactive power control amount (DELTA) Q of SC13 is corrected (decided) by following Formula (15), and a process is complete | finished. Otherwise, the reactive power control amount ΔQ is determined as it is without correction, and the process is terminated.

  According to the voltage control device 1 according to the present embodiment as described above, the voltage at the local end when estimated by the reactive power control amount determined in the first embodiment is estimated, The reactive power control amount of SC13 is determined based on the determined upper and lower limits. Therefore, it is possible to suppress reactive power control that deviates from a desired voltage range.

For example, the operational upper and lower voltage limits V _max and V _min may be set as the self-end voltage upper and lower limits V _smax and V _smin stored in the set value data unit 11 described above. Alternatively, the self-end voltage upper and lower limits V _smax and V _smin include, for example, the voltage increase ΔV _U [kV] due to PV5 downstream from the connection point of the higher system of the bank and the connection point, as in the second embodiment. Alternatively, upper and lower limits may be set in consideration of the voltage drop ΔV _L [kV] due to the load 6 downstream from.

That is, the reference system voltage is V _base [kV], the rated capacity Cpv _i [kW] of each PV5 existing downstream from the connection point of the higher system of the bank, and the feeder line impedance resistance of each PV5 from the connection point Based on the minute Rpv _i [kΩ], the voltage increase ΔV _U [kV] is calculated by the following equation (16). Similarly, the rated capacity Cload _i [kW] of each load 6 existing downstream from the connection point of the upper system of the bank, and the resistance Rload _i [kΩ] of the feeder line impedance of each load 6 from the connection point Based on the above, the voltage drop ΔV _L [kV] is calculated by the following equation (17).

Then, the values calculated by the following equations (18) and (19) may be set as the self-end voltage upper and lower limits V _smax and V _smin to be stored in the settling value data unit 11.

Note that the setting means for the self-end voltage upper and lower limits V _smax and V _smin described above are _merely examples, and of course, they may be set separately for the upper and lower limits, and are not limited to the setting means described above.

  DESCRIPTION OF SYMBOLS 1 Voltage control apparatus, 5 Solar power generation device (PV), 8 1st feeder, 9 2nd feeder, 10 Solar radiation amount measuring device, 11 Settling value data part, 12 Reactive power control amount determination part, 13 Phase advance capacitor (SC ), 14 solar radiation amount data part, 15 average solar radiation amount estimation part, 16 own device PV, 17 voltage measuring instrument.

Claims (6)

A voltage control device connected to the second feeder of the bank of the power distribution system including the first feeder to which the photovoltaic power generation device is connected, and the own end being the connection point;
A phase advance capacitor capable of controlling reactive power at its own end;
A first measuring instrument for measuring solar radiation in the vicinity of the end;
A setting that preserves a correlation between the amount of solar radiation measured by the first measuring instrument and a reactive power control amount of the phase advance capacitor capable of minimizing a voltage deviation between the first and second feeders. A value data section;
A voltage control device comprising: a reactive power control amount determining unit that determines a reactive power control amount of the phase advance capacitor at the end based on the amount of solar radiation measured by the first measuring instrument and the correlation . The voltage control device according to claim 1,
The resistance of the line impedance from the connection point to the upper system of the bank to the connection point with the first feeder of the solar power generation device, and the solar radiation measured by the first measuring instrument with the solar power generation device Based on the power estimated to generate power when receiving the same amount of solar radiation as the amount, estimate the respective voltage increase of the first and second feeders,
Based on these voltage rises and the reactance of the line impedance from the connection point to the upper system to the connection point to the second feeder of the voltage control device, the reactive power control amount related to the correlation is calculated. The voltage control device that you want. The voltage control apparatus according to claim 1 or 2,
A solar radiation amount data part for storing the solar radiation amount measured at a plurality of time points by the first measuring instrument;
An average solar radiation amount estimating unit that estimates an average solar radiation amount by averaging the solar radiation amount within a predetermined period stored in the solar radiation amount data unit;
The voltage control apparatus using the average solar radiation amount instead of the solar radiation amount measured by the first measuring instrument. The voltage control device according to any one of claims 1 to 3,
In addition to generating power based on sunlight irradiated in the voltage control device and measuring the power, a power generation measuring device is provided instead of the first measuring instrument,
A voltage control device using the power measured by the power generation measuring device instead of the amount of solar radiation measured by the first measuring instrument. The voltage control device according to claim 4,
The voltage control device uses the power generated by the power generation measurement device. A voltage control device according to any one of claims 1 to 5,
A second measuring instrument for measuring the voltage at the end;
The reactive power control amount determination unit
The reactive power control amount determined based on the amount of solar radiation measured by the first measuring instrument and the correlation, and the second feeder of the voltage control device from the connection point to the higher-level system of the bank Based on the reactance of the line impedance up to the connection point and the voltage at the own end measured by the second measuring instrument, the reactive power at the own end is controlled by the reactive power control amount. Estimating the voltage at the local end, and based on the estimated voltage at the local end and upper and lower limits predetermined for the voltage at the local end, invalidity of the phase advance capacitor at the local end A voltage control device that determines a power control amount.

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