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JP2017163743A - Power factor determination method, power factor determination system and power distribution system - Google Patents

Power factor determination method, power factor determination system and power distribution system Download PDF

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JP2017163743A
JP2017163743A JP2016047183A JP2016047183A JP2017163743A JP 2017163743 A JP2017163743 A JP 2017163743A JP 2016047183 A JP2016047183 A JP 2016047183A JP 2016047183 A JP2016047183 A JP 2016047183A JP 2017163743 A JP2017163743 A JP 2017163743A
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JP6638482B2 (en
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浩一 八田
Koichi Hatta
浩一 八田
守 田部
Mamoru Tanabe
守 田部
昇 柴丸
Noboru Shibamaru
昇 柴丸
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Chugoku Electric Power Co Inc
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Abstract

【課題】発電装置からの逆潮流電流が供給される配電線における電圧不平衡を抑制する。【解決手段】力率決定システム４０は、逆潮流電流を三相配電線１４に供給する発電装置２０の力率を決定する。力率決定システム４０は、三相配電分岐線１６のインピーダンスを取得するインピーダンス取得部と、力率を三相毎にそれぞれ指定力率に指定する力率指定部と、予め検出された三相配電分岐線１６の逆潮流電流値と指定力率とに基づき、指定力率である場合の三相配電分岐線１６の逆潮流電流値を、三相毎に算出する電流値算出部と、電流値とインピーダンスとに基づき、三相配電分岐線１６における電圧値を三相毎に算出する電圧算出部と、三相配電分岐線における電圧値に基づき、指定力率である場合の三相配電線１４での電圧不平衡率を算出する不平衡率算出部と、電圧不平衡率が所定の閾値以下である場合に指定力率を逆潮流電流の力率として決定する力率決定部とを有する。【選択図】図１An object of the present invention is to suppress voltage imbalance in a distribution line to which a reverse flow current from a power generator is supplied. A power factor determination system 40 determines a power factor of a power generator 20 that supplies a reverse power flow current to a three-phase distribution line 14. The power factor determination system 40 includes an impedance acquisition unit that acquires the impedance of the three-phase distribution branch line 16, a power factor designation unit that designates the power factor as a designated power factor for each of the three phases, and a three-phase distribution that is detected in advance. Based on the reverse flow current value of the branch line 16 and the specified power factor, a current value calculation unit that calculates the reverse flow current value of the three-phase distribution branch line 16 for each of the three phases when the specified power factor is obtained; And a three-phase distribution line 14 in the case of a specified power factor based on the voltage value in the three-phase distribution branch line based on the voltage value in the three-phase distribution branch line based on the voltage value in the three-phase distribution branch line And a power factor determination unit that determines the specified power factor as the power factor of the reverse flow current when the voltage imbalance factor is equal to or less than a predetermined threshold. [Selection] Figure 1

Description

本発明は、自然エネルギーによって発電する発電装置の力率決定方法、力率決定システム及び配電システムに関する。   The present invention relates to a power factor determination method, a power factor determination system, and a power distribution system for a power generation device that generates power using natural energy.

近年、自然エネルギーによって発電する太陽光発電装置などの発電装置が発電した電力を、電力会社に売却する（売電する）ケースが増加している。例えばメガソーラーなどの規模の大きい発電装置は、高圧配電線の幹線から分岐された分岐線を介して高圧配電線に連系（接続）される場合があり、発電した電力を三相交流電流に変換し、その三相交流電流を高圧配電線に流して、売電を行う。   In recent years, there has been an increasing number of cases where electric power generated by a power generation device such as a solar power generation device that generates power using natural energy is sold (sold) to an electric power company. For example, a large-scale power generator such as a mega solar system may be connected (connected) to a high-voltage distribution line via a branch line branched from the main line of the high-voltage distribution line. The power is sold by converting the three-phase alternating current through the high-voltage distribution line.

このように発電装置からの三相交流電流は、高圧配電線に流れる逆潮流電流となるため、高圧配電線における電圧上昇を引き起こすおそれがある。従来、高圧配電線における電圧上昇を抑制するため、発電装置は、三相交流電流を供給する際の力率を、進み力率にする場合がある。この場合の力率は、三相とも全て同じ値にしている。通常、力率は電力会社から指定された固定値を用いるが、例えば、特許文献１には、太陽光発電プラントにおいて、力率を制御している旨が記載されている。   Thus, the three-phase alternating current from the power generation device becomes a reverse power flow current flowing through the high-voltage distribution line, which may cause a voltage increase in the high-voltage distribution line. Conventionally, in order to suppress an increase in voltage in a high-voltage distribution line, the power generation device sometimes uses a leading power factor as a power factor when supplying a three-phase alternating current. The power factor in this case is the same for all three phases. Normally, the power factor uses a fixed value designated by an electric power company. For example, Patent Document 1 describes that a power factor is controlled in a solar power plant.

特表２０１４−５３３０８４号公報Special table 2014-533084 gazette

しかし、発電装置は、高圧配電線の線路インピーダンスの不平衡などの影響で、例えば配電用変電所から距離が離れるに従って電圧不平衡率が高くなる傾向にある。このような場合に発電装置の力率を三相全て同じにすると、配電用変電所近辺での電圧不平衡率は小さく保たれるが、配電用変電所から離れた場所における電圧不平衡率が高くなるおそれがある。   However, the power generation device tends to have a higher voltage unbalance rate as the distance from the distribution substation increases, for example, due to the influence of unbalance in the line impedance of the high-voltage distribution line. In such a case, if the power factor of the power generator is the same for all three phases, the voltage unbalance rate in the vicinity of the distribution substation is kept small, but the voltage unbalance rate at a location away from the distribution substation is May be high.

本発明は、上記課題を解決するために、発電装置からの逆潮流電流が供給される配電線における電圧不平衡を抑制する力率決定方法、力率決定システム及び配電システムを提供することを目的とする。   In order to solve the above-described problems, the present invention has an object to provide a power factor determination method, a power factor determination system, and a power distribution system that suppress voltage imbalance in a distribution line to which a reverse flow current from a power generator is supplied. And

上述した課題を解決し、目的を達成するために、本開示の力率決定方法は、発電所からの三相交流電流が供給される三相配電線に三相配電分岐線を介して接続されて、自然エネルギーによって発電した電力を三相交流の逆潮流電流として前記三相配電線に供給する発電装置が、前記逆潮流電流を供給する際の力率を決定する力率決定方法である。力率決定方法は、前記三相配電分岐線のインピーダンスを、三相毎に取得するインピーダンス取得ステップと、前記力率を、三相毎にそれぞれ所定の値である指定力率に指定する力率指定ステップと、予め検出された前記三相配電分岐線を流れる逆潮流電流の電流値と、前記指定力率とに基づき、前記指定力率である場合に前記三相配電分岐線に流れる逆潮流電流の電流値を、三相毎に算出する電流値算出ステップと、算出した前記電流値と前記インピーダンスとに基づき、前記三相配電分岐線における電圧値を、三相毎に算出する電圧算出ステップと、前記三相配電分岐線における三相毎の電圧値に基づき、前記指定力率である場合の逆潮流電流によって生じる前記三相配電線での電圧不平衡率を算出する不平衡率算出ステップと、前記電圧不平衡率が所定の閾値以下である場合に、前記指定力率を、前記発電装置が供給する逆潮流電流の力率として決定する力率決定ステップと、を有する。   In order to solve the above-described problems and achieve the object, the power factor determination method of the present disclosure is connected to a three-phase distribution line to which a three-phase alternating current from a power plant is supplied via a three-phase distribution branch line. This is a power factor determination method in which a power generation device that supplies power generated by natural energy to the three-phase distribution line as a three-phase AC reverse flow current determines the power factor when supplying the reverse flow current. The power factor determination method includes an impedance acquisition step for acquiring the impedance of the three-phase distribution branch line for each of the three phases, and a power factor for specifying the power factor to a specified power factor that is a predetermined value for each of the three phases. Based on the specified step, the current value of the reverse flow current flowing through the three-phase distribution branch line detected in advance, and the specified power factor, the reverse power flow that flows through the three-phase distribution branch line when the specified power factor is reached A current value calculating step for calculating the current value of the current for each of the three phases; and a voltage calculating step for calculating the voltage value in the three-phase distribution branch line for each of the three phases based on the calculated current value and the impedance. And an unbalance rate calculation step for calculating a voltage unbalance rate in the three-phase distribution line generated by a reverse power flow current in the case of the specified power factor based on a voltage value for each of the three phases in the three-phase distribution branch line; , The electric If unbalance ratio is equal to or less than the predetermined threshold value, the designated power factor, having a power factor determining step of determining a power factor of the reverse flow current the power plant supplies.

前記力率決定方法は、前記力率指定ステップと前記電流値算出ステップと前記不平衡率算出ステップとを、前記指定力率の値を変化させながら繰り返し実行し、前記力率決定ステップが、そのうちで前記電圧不平衡率が最小となった前記指定力率を、前記発電装置が供給する逆潮流電流の力率として決定することが好ましい。   The power factor determination method repeatedly executes the power factor designation step, the current value calculation step, and the unbalance rate calculation step while changing the value of the designated power factor, and the power factor determination step includes: It is preferable that the specified power factor at which the voltage imbalance rate is minimized is determined as the power factor of the reverse flow current supplied by the power generator.

前記力率決定方法において、前記力率指定ステップは、三相の指定力率の平均値が、所定の平均力率値となるように、前記指定力率を指定することが好ましい。   In the power factor determination method, it is preferable that the power factor designation step designates the designated power factor so that an average value of the three-phase designated power factors becomes a predetermined average power factor value.

前記力率決定方法において、前記平均力率値は、０．８５以上１以下であることが好ましい。   In the power factor determination method, the average power factor value is preferably 0.85 or more and 1 or less.

前記力率決定方法において、前記力率指定ステップは、０．８５以上１以下の範囲で、三相の指定力率をそれぞれ指定することが好ましい。   In the power factor determination method, the power factor designation step preferably designates a three-phase designated power factor within a range of 0.85 to 1.

上述した課題を解決し、目的を達成するために、本開示の力率決定システムは、発電所からの三相交流電流が供給される三相配電線に三相配電分岐線を介して接続されて、自然エネルギーによって発電した電力を三相交流の逆潮流電流として前記三相配電線に供給する発電装置が、前記逆潮流電流を供給する際の力率を決定する。力率決定システムは、前記三相配電分岐線のインピーダンスを、三相毎に取得するインピーダンス取得部と、前記力率を、三相毎にそれぞれ所定の値である指定力率に指定する力率指定部と、予め検出された前記三相配電分岐線を流れる逆潮流電流の電流値と、前記指定力率とに基づき、前記指定力率である場合に前記三相配電分岐線に流れる逆潮流電流の電流値を、三相毎に算出する電流値算出部と、算出した前記電流値と前記インピーダンスとに基づき、前記三相配電分岐線における電圧値を、三相毎に算出する電圧算出部と、前記三相配電分岐線における三相毎の電圧値に基づき、前記指定力率である場合の逆潮流電流によって生じる前記三相配電線での電圧不平衡率を算出する不平衡率算出部と、前記電圧不平衡率が所定の閾値以下である場合に、前記指定力率を、前記発電装置が供給する逆潮流電流の力率として決定する力率決定部と、を有する。   In order to solve the above-described problems and achieve the object, the power factor determination system of the present disclosure is connected to a three-phase distribution line supplied with a three-phase alternating current from a power plant via a three-phase distribution branch line. A power generation device that supplies electric power generated by natural energy to the three-phase distribution line as a three-phase AC reverse flow current determines a power factor for supplying the reverse flow current. The power factor determination system includes an impedance acquisition unit that acquires the impedance of the three-phase distribution branch line for each of the three phases, and a power factor that specifies the specified power factor that is a predetermined value for each of the three phases. Based on the specified unit, the current value of the reverse power flow current flowing through the three-phase distribution branch line detected in advance, and the specified power factor, the reverse power flow through the three-phase distribution branch line when the specified power factor is reached A current value calculation unit for calculating the current value of the current for each of the three phases, and a voltage calculation unit for calculating the voltage value in the three-phase distribution branch line for each of the three phases based on the calculated current value and the impedance. And, based on the voltage value for each of the three phases in the three-phase distribution branch line, an unbalance rate calculation unit that calculates a voltage unbalance rate in the three-phase distribution line caused by a reverse power flow current at the specified power factor; and The voltage imbalance rate is below a predetermined threshold In one case, the designated power factor, having a power factor determination unit that determines the power generator as the power factor of the reverse flow current supplied.

上述した課題を解決し、目的を達成するために、本開示の配電システムは、自然エネルギーによって発電する発電部と、発電所からの三相交流電流が供給される三相配電線に三相配電分岐線を介して接続されて、前記発電部が発電した電力を三相交流の逆潮流電流として前記三相配電線に供給する出力制御部と、前記出力制御部が前記逆潮流電流を供給する際の力率を決定する決定する力率決定システムと、を有する。前記力率決定システムは、前記三相配電分岐線のインピーダンスを、三相毎に取得するインピーダンス取得部と、前記力率を、三相毎にそれぞれ所定の値である指定力率に指定する力率指定部と、予め検出された前記三相配電分岐線を流れる逆潮流電流の電流値と、前記指定力率とに基づき、前記指定力率である場合に前記三相配電分岐線に流れる逆潮流電流の電流値を、三相毎に算出する電流値算出部と、算出した前記電流値と前記インピーダンスとに基づき、前記三相配電分岐線における電圧値を、三相毎に算出する電圧算出部と、前記三相配電分岐線における三相毎の電圧値に基づき、前記指定力率である場合の逆潮流電流によって生じる前記三相配電線での電圧不平衡率を算出する不平衡率算出部と、前記電圧不平衡率が所定の閾値以下である場合に、前記指定力率を、前記発電装置が供給する逆潮流電流の力率として決定する力率決定部と、を有し、前記出力制御部は、前記力率決定部が決定した力率で、前記逆潮流電流を供給する。   In order to solve the above-described problems and achieve the object, the power distribution system of the present disclosure includes a power generation unit that generates power using natural energy and a three-phase power distribution branch to a three-phase power distribution line that is supplied with a three-phase alternating current from the power plant An output control unit that is connected via a wire and supplies the power generated by the power generation unit to the three-phase distribution line as a three-phase AC reverse power flow current, and the output control unit supplies the reverse power flow current. A power factor determination system for determining a power factor. The power factor determination system includes an impedance acquisition unit that acquires the impedance of the three-phase distribution branch line for each of the three phases, and a power that specifies the specified power factor for each of the three phases as a predetermined power factor. Based on the rate designation unit, the current value of the reverse flow current flowing through the three-phase distribution branch line detected in advance, and the designated power factor, the reverse flow that flows through the three-phase distribution branch line when the designated power factor is reached Based on the calculated current value and the impedance, the voltage value for calculating the voltage value in the three-phase distribution branch line for each of the three phases is calculated based on the calculated current value and the impedance. And an unbalance rate calculation unit that calculates a voltage unbalance rate in the three-phase distribution line caused by a reverse power flow current at the specified power factor based on a voltage value for each of the three phases in the three-phase distribution branch line And the voltage imbalance rate is a predetermined threshold value. A power factor determination unit that determines the specified power factor as a power factor of a reverse flow current supplied by the power generation device when the power factor is lower, and the power factor determination unit determines the output control unit The reverse flow current is supplied at the power factor.

本発明によれば、発電装置からの逆潮流電流が供給される配電線における電圧不平衡を抑制することが可能となる。   ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress the voltage imbalance in the distribution line with which the reverse power flow current from a generator is supplied.

図１は、本実施形態に係る配電システムを示す模式図である。FIG. 1 is a schematic diagram showing a power distribution system according to the present embodiment. 図２は、本実施形態に係る力率決定システムの模式的なブロック図である。FIG. 2 is a schematic block diagram of the power factor determination system according to the present embodiment. 図３は、電流値取得部が取得した電流値の情報を示すテーブルの一例である。FIG. 3 is an example of a table showing information on current values acquired by the current value acquisition unit. 図４は、装柱の例を示す図である。FIG. 4 is a diagram illustrating an example of a pillar. 図５は、装柱の例を示す図である。FIG. 5 is a diagram illustrating an example of a pillar. 図６は、本実施形態に係る出力制御部の構成を模式的に示すブロック図である。FIG. 6 is a block diagram schematically showing the configuration of the output control unit according to the present embodiment. 図７は、本実施形態に係る力率の決定フローを説明するフローチャートである。FIG. 7 is a flowchart for explaining a power factor determination flow according to this embodiment. 図８は、本実施形態に係る出力制御部による力率の制御フローを示すフローチャートである。FIG. 8 is a flowchart showing a control flow of the power factor by the output control unit according to the present embodiment.

以下に添付図面を参照して、本発明の好適な実施形態を詳細に説明する。なお、この実施形態により本発明が限定されるものではなく、また、実施形態が複数ある場合には、各実施例を組み合わせて構成するものも含むものである。   Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, Moreover, when there are two or more embodiments, what comprises a combination of each Example is also included.

図１は、本実施形態に係る配電システムを示す模式図である。図１に示すように、配電システム１は、発電所１０、送電線１１、配電用変電所１２、三相配電線１４、三相配電分岐線１６、分岐線１７、発電装置２０、検出部３０、力率決定システム４０、柱上変圧器Ｔｒ、及び負荷Ｒを有する。配電システム１は、発電所１０より送電線１１を介して送電される電力を配電用変電所１２により降圧し、三相配電線１４、三相配電分岐線１６及び分岐線１７により配電し、柱上変圧器Ｔｒを介して家庭等の負荷Ｒに配電する。   FIG. 1 is a schematic diagram showing a power distribution system according to the present embodiment. As shown in FIG. 1, the power distribution system 1 includes a power plant 10, a transmission line 11, a distribution substation 12, a three-phase distribution line 14, a three-phase distribution branch line 16, a branch line 17, a power generation device 20, a detection unit 30, A power factor determination system 40, a pole transformer Tr, and a load R are included. The distribution system 1 steps down the power transmitted from the power plant 10 through the transmission line 11 by the distribution substation 12, distributes the power through the three-phase distribution line 14, the three-phase distribution branch line 16, and the branch line 17, The power is distributed to a load R such as a home via the transformer Tr.

発電所１０は、例えば火力発電所などの発電設備であり、配電システム１に属する負荷Ｒに必要な電力を供給する。送電線１１は、発電所１０が発電した三相交流電力が送電される。送電線１１は、例えば６６ｋＶ（キロボルト）の電圧振幅を有する送電用の三相交流電力が送電される。配電用変電所１２は、送電線１１と電気的に接続される変圧器を有する設備である。配電用変電所１２は、送電線１１に送電された６６ｋＶの送電用の三相交流電力を、６．６ｋＶの電圧振幅を有する配電用の三相交流電力に降圧する。以下、発電所から送電され、６．６ｋＶに降圧された配電用の三相交流電力により流れる三相交流電流を、配電電流Ｉａと記載する。配電電流Ｉａは、三相交流電流のうちの第１相であるＡ相配電電流ＩａＡと、第２相であるＢ相配電電流ＩａＢと、第３相であるＣ相配電電流ＩａＣとを有する。負荷が三相平衡である場合、Ａ相配電電流ＩａＡ、Ｂ相配電電流ＩａＢ、Ｃ相配電電流ＩａＣは、それぞれ電流値の振幅が等しい。また、Ｂ相配電電流ＩａＢは、Ａ相配電電流ＩａＡよりも１２０°位相が遅れている。Ｃ相配電電流ＩａＣは、Ｂ相配電電流ＩａＢよりも、１２０°位相が遅れている。   The power plant 10 is a power generation facility such as a thermal power plant, for example, and supplies necessary power to a load R belonging to the power distribution system 1. The transmission line 11 transmits three-phase AC power generated by the power plant 10. The transmission line 11 transmits, for example, three-phase AC power for transmission having a voltage amplitude of 66 kV (kilovolts). The distribution substation 12 is a facility having a transformer that is electrically connected to the transmission line 11. The distribution substation 12 steps down the 66 kV transmission three-phase AC power transmitted to the transmission line 11 to the distribution three-phase AC power having a voltage amplitude of 6.6 kV. Hereinafter, the three-phase alternating current that is transmitted from the power plant and flows by the three-phase alternating current power for distribution that has been stepped down to 6.6 kV is referred to as a distribution current Ia. The distribution current Ia includes an A-phase distribution current IaA that is the first phase of the three-phase alternating current, a B-phase distribution current IaB that is the second phase, and a C-phase distribution current IaC that is the third phase. When the load is three-phase balanced, the A-phase distribution current IaA, the B-phase distribution current IaB, and the C-phase distribution current IaC have the same current value amplitude. Further, the B phase distribution current IaB is 120 ° out of phase with respect to the A phase distribution current IaA. The phase C distribution current IaC is delayed by 120 ° from the phase B distribution current IaB.

三相配電線１４は、発電所からの三相交流電流、より詳しくは配電電流Ｉａが配電される配電線である。三相配電線１４は、一方の端部である上流端１４Ｓが配電用変電所１２と電気的に接続される。三相配電線１４は、配電用変電所１２から配電電流Ｉａが配電される。三相配電線１４は、他方の端部である下流端１４Ｔが開放されている。三相配電線１４は、Ａ相配電電流ＩａＡが配電されるＡ相配電線１４Ａと、Ｂ相配電電流ＩａＢが配電されるＢ相配電線１４Ｂと、Ｃ相配電電流ＩａＣが配電されるＣ相配電線１４Ｃとを有する。   The three-phase distribution line 14 is a distribution line to which a three-phase alternating current from the power plant, more specifically, a distribution current Ia is distributed. The three-phase distribution line 14 is electrically connected to the distribution substation 12 at the upstream end 14 </ b> S, which is one end. The three-phase distribution line 14 receives the distribution current Ia from the distribution substation 12. The three-phase distribution line 14 is open at the downstream end 14T, which is the other end. The three-phase distribution line 14 includes a A-phase distribution line 14A to which the A-phase distribution current IaA is distributed, a B-phase distribution line 14B to which the B-phase distribution current IaB is distributed, and a C-phase distribution line 14C to which the C-phase distribution current IaC is distributed. Have

三相配電線１４は、ノードＮ１において、三相配電分岐線１６が接続されている。三相配電分岐線１６は、Ａ相分岐線１６Ａと、Ｂ相分岐線１６Ｂと、Ｃ相分岐線１６Ｃとを有する。三相配電分岐線１６は、Ａ相分岐線１６ＡがＡ相配電線１４Ａに接続され、Ｂ相分岐線１６ＢがＢ相配電線１４Ｂに接続され、Ｃ相分岐線１６ＣがＣ相配電線１４Ｃに接続されている。また、三相配電線１４は、ノードＮ１よりも下流端１４Ｔ側のノードＮ２において、柱上変圧器Ｔｒに接続されている。柱上変圧器Ｔｒは、例えば配電用の三相交流電力の電圧振幅（６．６ｋＶ）を、１００Ｖ又は２００Ｖの電圧振幅を有する負荷用電力に降圧する。柱上変圧器Ｔｒは、負荷Ｒに接続されている。負荷Ｒは、例えば家庭や工場などの電気機器である。柱上変圧器Ｔｒは、降圧した電力により発生する電流を負荷Ｒに配電する。なお、柱上変圧器Ｔｒは、定格容量（ｋＶＡ）が定められている。柱上変圧器Ｔｒは、定格容量で定めた電力量の範囲内で電力（電流）を配電する。なお、Ａ相配電電流ＩａＡ、Ｂ相配電電流ＩａＢ、及びＣ相配電電流ＩａＣの値は、位置によって変化する。例えば、配電用変電所１２とノードＮ１との間では、Ａ相配電電流ＩａＡとしてＡ相配電電流ＩａＡ（Ｎ０Ｎ１）が流れ、Ｂ相配電電流ＩａＢとしてＢ相配電電流ＩａＢ（Ｎ０Ｎ１）が流れ、Ｃ相配電電流ＩａＣとしてＣ相配電電流ＩａＣ（Ｎ０Ｎ１）が流れる。ノードＮ１において、電流は分岐線１６に分岐しているため、ノードＮ１とノードＮ２との間では、Ａ相配電電流ＩａＡとしてＡ相配電電流ＩａＡ（Ｎ１Ｎ２）が流れ、Ｂ相配電電流ＩａＢとしてＢ相配電電流ＩａＢ（Ｎ１Ｎ２）が流れ、Ｃ相配電電流ＩａＣとしてＣ相配電電流ＩａＣ（Ｎ１Ｎ２）が流れる。Ａ相配電電流ＩａＡ（Ｎ１Ｎ２）の電流値は、Ａ相配電電流ＩａＡ（Ｎ０Ｎ１）の電流値からＡ相分岐線１６Ａに分岐された電流値を差し引いた値となる。Ｂ相配電電流ＩａＢ（Ｎ１Ｎ２）及びＣ相配電電流ＩａＣ（Ｎ１Ｎ２）も同様である。 Three-phase distribution line 14 at node N 1, the three-phase power distribution branch line 16 is connected. The three-phase distribution branch line 16 includes an A-phase branch line 16A, a B-phase branch line 16B, and a C-phase branch line 16C. In the three-phase distribution branch line 16, the A-phase branch line 16A is connected to the A-phase distribution line 14A, the B-phase branch line 16B is connected to the B-phase distribution line 14B, and the C-phase branch line 16C is connected to the C-phase distribution line 14C. Yes. Also, three-phase distribution line 14 at node N 2 of the downstream end 14T side of the node N 1, are connected to pole transformer Tr. The pole transformer Tr steps down the voltage amplitude (6.6 kV) of the three-phase AC power for distribution, for example, to the load power having a voltage amplitude of 100V or 200V. The pole transformer Tr is connected to the load R. The load R is an electrical device such as a home or a factory. The pole transformer Tr distributes the current generated by the stepped down power to the load R. The pole transformer Tr has a rated capacity (kVA). The pole transformer Tr distributes electric power (current) within a range of electric power determined by the rated capacity. Note that the values of the A-phase distribution current IaA, the B-phase distribution current IaB, and the C-phase distribution current IaC vary depending on the position. For example, between the distribution substation 12 and the node N 1, the A-phase power distribution current IaA (N0N1) flows as the A-phase power distribution current IaA, B-phase power distribution current IAB as B-phase power distribution current IaB (N0N1) flows, C-phase distribution current IaC (N0N1) flows as C-phase distribution current IaC. In the node N 1, since the current is branched to the branch line 16, a node in between the N 1 and the node N 2, A-phase power distribution current IaA as A-phase power distribution current IaA (N1N2) flows, B-phase power distribution current B phase distribution current IaB (N1N2) flows as IaB , and C phase distribution current IaC (N1N2) flows as C phase distribution current IaC. Current value of the A-phase power distribution current IaA (N1N2) is a value obtained by subtracting the current value which is branched to the A-phase branch line 16A from the current value of the A-phase power distribution current IaA (N0N1). The same applies to the B-phase distribution current IaB (N1N2) and the C-phase distribution current IaC (N1N2) .

このように、ノードＮ１、Ｎ２は、三相配電線１４からの分岐線や、柱上変圧器Ｔｒなどが接続される連系点であり、ノードの数、配列順、及びノードに接続されている対象物は、図１に示すものに限られない。すなわち、三相配電線１４は、三相配電分岐線１６及び柱上変圧器Ｔｒに接続されていれば、その接続対象物の数及び配列順は、図１の例に限られず任意である。 Thus, the nodes N 1 and N 2 are interconnection points to which the branch lines from the three-phase distribution lines 14 and the pole transformer Tr are connected, and are connected to the number of nodes, the order of arrangement, and the nodes. The target object is not limited to that shown in FIG. That is, as long as the three-phase distribution line 14 is connected to the three-phase distribution branch line 16 and the pole transformer Tr, the number and arrangement order of the connection objects are not limited to the example of FIG. 1 and are arbitrary.

三相配電分岐線１６は、ノードＮ１、すなわち三相配電線１４との接続箇所（連系点）と反対側の端部に、発電装置２０が接続されている。また、三相配電分岐線１６は、ノードＮ１と発電装置２０の接続箇所との間のノードＮ３において、柱上変圧器Ｔｒ及び負荷Ｒが接続されている。また、三相配電分岐線１６は、ノードＮ３と発電装置２０の接続箇所との間のノードＮ４において、分岐線１７に接続されている。分岐線１７は、図示しない複数の柱上変圧器Ｔｒ及び負荷Ｒに接続される配電分岐線である。 The three-phase distribution branch line 16 is connected to the power generation device 20 at the end opposite to the connection point (interconnection point) with the node N 1 , that is, the three-phase distribution line 14. The three-phase distribution branch line 16 is connected to the pole transformer Tr and the load R at the node N 3 between the node N 1 and the connection point of the power generation device 20. Further, the three-phase distribution branch line 16 is connected to the branch line 17 at the node N 4 between the node N 3 and the connection point of the power generation device 20. The branch line 17 is a distribution branch line connected to a plurality of pole transformers Tr and a load R (not shown).

また、三相配電分岐線１６は、ノードＮ１の近傍、すなわち三相配電線１４との接続箇所の近傍で、検出部３０が接続されている。三相配電線１４との接続箇所の近傍とは、ノードＮ１とノードＮ３との間であり、より詳しくは、三相配電分岐線１６において、三相配電線１４との接続箇所（本実施形態ではノードＮ１）よりも発電装置２０側であって、かつ、最も三相配電線１４側で分岐線や柱上変圧器Ｔｒに接続されている箇所（本実施形態ではノードＮ３）よりも三相配電線１４側の位置をいう。 The three-phase distribution branch line 16 is connected to the detection unit 30 in the vicinity of the node N 1 , that is, in the vicinity of the connection portion with the three-phase distribution line 14. The vicinity of the connection point with the three-phase distribution line 14 is between the node N 1 and the node N 3. More specifically, the connection point with the three-phase distribution line 14 in the three-phase distribution branch line 16 (this embodiment) Then, it is closer to the power generator 20 side than the node N 1 ), and more than the point connected to the branch line or pole transformer Tr on the three-phase distribution line 14 side (node N 3 in this embodiment). It refers to the position on the phase distribution line 14 side.

このように、ノードＮ３、Ｎ４は、三相配電分岐線１６からの分岐線１７や、柱上変圧器Ｔｒなどが接続される連系点であり、ノードの数、配列順、及びノードに接続されている対象物は、図１に示すものに限られない。すなわち、三相配電分岐線１６は、一方が三相配電線１４に接続され、他方が発電装置２０に接続されていれば、その接続対象物の数及び配列順は、図１の例に限られず任意である。 Thus, the nodes N 3 and N 4 are interconnection points to which the branch line 17 from the three-phase power distribution branch line 16, the pole transformer Tr, and the like are connected, and the number of nodes, the order of arrangement, and the node The object connected to is not limited to that shown in FIG. That is, as long as one of the three-phase distribution branch lines 16 is connected to the three-phase distribution line 14 and the other is connected to the power generation apparatus 20, the number and arrangement order of the connection objects are not limited to the example of FIG. is there.

発電装置２０は、自然エネルギー（再生可能エネルギー）によって発電する発電装置である。本実施形態における発電装置２０は、太陽光によって発電する太陽光発電装置であり、より詳しくは、発電装置２０は、例えば１ＭＷ以上の出力を持つ太陽光発電システム（メガソーラー）である。発電装置２０は、発電部２２及び出力制御部２４を有する。発電部２２は、自然エネルギーによって発電するものであり、本実施形態では、太陽光によって発電する太陽光発電パネルである。出力制御部２４は、発電部２２に接続され、発電部２２が発電した電流を、三相交流電流として三相配電分岐線１６に出力する制御装置である。詳しくは後述するが、本実施形態における出力制御部２４は、ＰＣＳ（Power Conditioning System）であり、発電部２２が発電した直流電流を、三相交流電流に変換し、かつ、力率決定システム４０が決定した力率で、三相交流電流を三相配電分岐線１６に出力する。ただし、発電装置２０は、自然エネルギーによって発電する発電装置であれば、太陽光発電装置に限られず、例えば風力によって発電する風力発電装置などであってもよい。   The power generation device 20 is a power generation device that generates power using natural energy (renewable energy). The power generation device 20 in the present embodiment is a solar power generation device that generates power using sunlight, and more specifically, the power generation device 20 is a solar power generation system (mega solar) having an output of 1 MW or more, for example. The power generation device 20 includes a power generation unit 22 and an output control unit 24. The power generation unit 22 generates power using natural energy, and is a solar power generation panel that generates power using sunlight in the present embodiment. The output control unit 24 is a control device that is connected to the power generation unit 22 and outputs the current generated by the power generation unit 22 to the three-phase distribution branch line 16 as a three-phase alternating current. As will be described in detail later, the output control unit 24 in the present embodiment is a PCS (Power Conditioning System), converts the direct current generated by the power generation unit 22 into a three-phase alternating current, and the power factor determination system 40. The three-phase alternating current is output to the three-phase distribution branch line 16 with the power factor determined by However, the power generation device 20 is not limited to a solar power generation device as long as it is a power generation device that generates power using natural energy, and may be, for example, a wind power generation device that generates power using wind power.

三相配電分岐線１６は、三相配電線１４から配電電流Ｉａの一部が分岐して供給される。具体的には、Ａ相分岐線１６Ａは、Ａ相配電電流ＩａＡから分岐された電流が供給される。Ｂ相分岐線１６Ｂは、Ｂ相配電電流ＩａＢから分岐された電流が供給される。Ｃ相分岐線１６Ｃは、Ｃ相配電電流ＩａＣから分岐された電流が供給される。これらの電流は、三相配電分岐線１６において、三相配電線１４のノードＮ１から、発電装置２０に向かって流れる電流である。一方、三相配電分岐線１６は、例えばノードＮ４において、発電装置２０から三相交流電流が供給される。この発電装置２０から三相配電分岐線１６に供給される三相交流電流は、発電装置２０から三相配電線１４に向かって流れる逆潮流電流である。以下、三相配電分岐線１６を流れる電流を、逆方向（発電装置２０から三相配電線１４に向かう方向）を正としてＩｂと記載する。逆潮流電流Ｉｂは、三相配電分岐線１６を介して、ノードＮ１から三相配電線１４に供給される。発電装置２０は、このようにして、発電した電力を逆潮流電流Ｉｂとして三相配電線１４に供給する。 The three-phase distribution branch line 16 is supplied with a part of the distribution current Ia branched from the three-phase distribution line 14. Specifically, the current branched from the A-phase distribution current IaA is supplied to the A-phase branch line 16A. The B-phase branch line 16B is supplied with a current branched from the B-phase distribution current IaB. The current branched from the C-phase distribution current IaC is supplied to the C-phase branch line 16C. These currents are currents that flow from the node N 1 of the three-phase distribution line 14 toward the power generation device 20 in the three-phase distribution branch line 16. On the other hand, the three-phase distribution branch line 16 is supplied with a three-phase alternating current from the power generator 20 at, for example, the node N 4 . The three-phase alternating current supplied from the power generator 20 to the three-phase distribution branch line 16 is a reverse power flow current flowing from the power generator 20 toward the three-phase distribution line 14. Hereinafter, the current flowing through the three-phase distribution branch line 16 is referred to as Ib with the reverse direction (the direction from the power generator 20 toward the three-phase distribution line 14) being positive. The reverse flow current Ib is supplied from the node N 1 to the three-phase distribution line 14 via the three-phase distribution branch line 16. The power generator 20 supplies the generated power to the three-phase distribution line 14 as the reverse power flow current Ib in this way.

逆潮流電流Ｉｂは、三相交流電流のうちの第１相であるＡ相逆潮流電流ＩｂＡと、第２相であるＢ相逆潮流電流ＩｂＢと、第３相であるＣ相逆潮流電流ＩｂＣとを有する。電流が三相平衡の場合、Ｂ相逆潮流電流ＩｂＢは、Ａ相逆潮流電流ＩｂＡよりも１２０°位相が遅れている。Ｃ相逆潮流電流ＩｂＣは、Ｂ相逆潮流電流ＩｂＢよりも、１２０°位相が遅れている。発電装置２０は、力率を制御しない場合、ノードＮ４の電圧から指定した力率でＡ相逆潮流電流ＩｂＡ、Ｂ相逆潮流電流ＩｂＢ、Ｃ相逆潮流電流ＩｂＣを供給する。また、Ａ相逆潮流電流ＩｂＡ、Ｂ相逆潮流電流ＩｂＢ、Ｃ相逆潮流電流ＩｂＣの値は、位置によって変化する。例えば、発電装置２０とノードＮ４との間では、Ａ相逆潮流電流ＩｂＡとしてＡ相逆潮流電流ＩｂＡ（Ｎ４）が流れ、Ｂ相逆潮流電流ＩｂＢとしてＢ相逆潮流電流ＩｂＢ（Ｎ４）が流れ、Ｃ相逆潮流電流ＩｂＣとしてＣ相逆潮流電流ＩｂＣ（Ｎ４）が流れる。ノードＮ４において、電流は分岐線１７に分岐しているため、ノードＮ３とノードＮ４との間では、Ａ相逆潮流電流ＩｂＡとしてＡ相逆潮流電流ＩｂＡ（Ｎ３Ｎ４）が流れ、Ｂ相逆潮流電流ＩｂＢとしてＢ相逆潮流電流ＩｂＢ（Ｎ３Ｎ４）が流れ、Ｃ相逆潮流電流ＩｂＣとしてＣ相逆潮流電流ＩｂＣ（Ｎ３Ｎ４）が流れる。同様に、ノードＮ３において電流を負荷Ｒに分岐しているため、ノードＮ１とノードＮ３との間では、Ａ相逆潮流電流ＩｂＡとしてＡ相逆潮流電流ＩｂＡ（Ｎ１Ｎ３）が流れ、Ｂ相逆潮流電流ＩｂＢとしてＢ相逆潮流電流ＩｂＢ（Ｎ１Ｎ３）が流れ、Ｃ相逆潮流電流ＩｂＣとしてＣ相逆潮流電流ＩｂＣ（Ｎ１Ｎ３）が流れる。 The reverse flow current Ib includes a first-phase A-phase reverse flow current IbA, a second-phase B-phase reverse flow current IbB, and a third-phase C-phase reverse flow current IbC. And have. When the current is three-phase balanced, the B-phase reverse flow current IbB is 120 ° behind the A-phase reverse flow current IbA. The C-phase reverse flow current IbC is 120 ° out of phase with the B-phase reverse flow current IbB. Power generator 20, if not control the power factor and supplies A phase inverse tidal current IbA, B phase inverse tidal current IBB, the C phase inverse tidal current IbC power factor specified from the voltage of the node N 4. The values of the A-phase reverse power flow current IbA, the B-phase reverse power flow current IbB, and the C-phase reverse power flow current IbC vary depending on the position. For example, between the power generator 20 and the node N 4 , an A-phase reverse flow current IbA (N4) flows as the A-phase reverse flow current IbA, and a B-phase reverse flow current IbB (N4) as the B-phase reverse flow current IbB. The C-phase reverse flow current IbC (N4) flows as the C-phase reverse flow current IbC. In the node N 4, current is because of the branches in the branch line 17, between the node N 3 and the node N 4, A phase inverse tidal current IbA (N3N4) as A phase inverse tide current IbA flows, B phase A B-phase reverse flow current IbB (N3N4) flows as the reverse flow current IbB, and a C-phase reverse flow current IbC (N3N4) flows as the C-phase reverse flow current IbC. Similarly, since the branch current to the load R in the node N3, the between node N 1 and the node N 3, A phase inverse tidal current IbA (N1N3) as A phase inverse tide current IbA flows, B phase A B-phase reverse flow current IbB (N1N3) flows as the reverse flow current IbB, and a C-phase reverse flow current IbC (N1N3) flows as the C-phase reverse flow current IbC.

検出部３０は、上述のように、ノードＮ１近傍で三相配電分岐線１６に接続されている。検出部３０は、ノードＮ１近傍において三相配電分岐線１６を流れる逆潮流電流Ｉｂの電流値を検出する。また、検出部３０は、ノードＮ１近傍で三相配電分岐線１６に接続されていることに限られず、三相配電分岐線１６の任意の箇所に接続されてもよい。例えば、検出部３０は、計測機能付開閉器として設けられていてもよい。 Detector 30, as described above, it is connected to a three phase power distribution branch line 16 at node N 1 neighborhood. Detector 30 detects the current value of the reverse flow current Ib flowing through the three-phase power distribution branch line 16 at the node N 1 neighborhood. Further, the detection unit 30 is not limited to being connected to the three-phase distribution branch line 16 in the vicinity of the node N 1 , and may be connected to an arbitrary portion of the three-phase distribution branch line 16. For example, the detection unit 30 may be provided as a switch with a measurement function.

力率決定システム４０は、発電装置２０が三相配電分岐線１６に逆潮流電流Ｉｂを供給する際の力率を決定するシステムである。力率とは、有効電力と無効電力との比率を示すものである。力率をＯとし、有効電力をＰとし、無効電力をＱとすると、力率Ｏは、次の式（１）で表される。   The power factor determination system 40 is a system that determines the power factor when the power generation apparatus 20 supplies the reverse power flow current Ib to the three-phase distribution branch line 16. The power factor indicates the ratio between active power and reactive power. When the power factor is O, the active power is P, and the reactive power is Q, the power factor O is expressed by the following equation (1).

Figure 2017163743
Figure 2017163743

力率決定システム４０は、発電装置２０が三相配電分岐線１６に逆潮流電流Ｉｂを供給する際の力率を、三相毎に決定する。言い換えれば、力率決定システム４０は、Ａ相逆潮流電流ＩｂＡに対応する電力をＡ相分岐線１６Ａに供給する際の力率ＯＡと、Ｂ相逆潮流電流ＩｂＢに対応する電力をＢ相分岐線１６Ｂに供給する際の力率ＯＢと、Ｃ相逆潮流電流ＩｂＣに対応する電力をＣ相分岐線１６Ｃに供給する際の力率ＯＣとを決定する。また、本実施形態において、力率決定システム４０は、営業所１００に設けられている。営業所１００は、配電システム１の制御を行う作業員が待機している場所である。ただし、力率決定システム４０が設けられている箇所は任意であり、例えば発電所、変電所、又は発電装置２０と同じ施設などに設けられていてもよい。力率決定システム４０の詳細な説明については、後述する。   The power factor determination system 40 determines, for each of the three phases, the power factor when the power generation apparatus 20 supplies the reverse power flow current Ib to the three-phase distribution branch line 16. In other words, the power factor determination system 40 supplies the power factor OA when supplying the power corresponding to the A-phase reverse flow current IbA to the A-phase branch line 16A and the power corresponding to the B-phase reverse flow current IbB as the B-phase branch. The power factor OB when supplying the line 16B and the power factor OC when supplying the power corresponding to the C-phase reverse flow current IbC to the C-phase branch line 16C are determined. In the present embodiment, the power factor determination system 40 is provided in the sales office 100. The sales office 100 is a place where a worker who controls the power distribution system 1 is waiting. However, the place where the power factor determination system 40 is provided is arbitrary, and may be provided in the same facility as the power plant, the substation, or the power generation device 20, for example. Details of the power factor determination system 40 will be described later.

（電圧不平衡について）
負荷がある程度に平衡に管理されている配電線では、幹線において電圧不平衡率の増加が大きくなる傾向にある。従って、力率決定システム４０は、幹線である三相配電線１４に逆潮流電流Ｉｂが供給された際に、三相配電線１４における電圧不平衡率が高くなることを抑制するために、力率ＯＡ、ＯＢ、ＯＣをそれぞれ個別に決定している。電圧不平衡とは、各線間電圧の振幅が等しく、且つ、線間電圧の位相が１２０°異なる三相交流電圧において、各線間電圧の振幅が異なったり、線間電圧の位相がずれたりすることである。各線間電圧の振幅が異なるとは、例えばＡ相電流における電圧振幅と、Ｂ相電流における電圧振幅と、Ｃ相電流における電圧振幅とが互いに異なることをいう。また、線間電圧の位相がずれるとは、例えば、Ａ相電圧とＢ相電圧との位相差、Ｂ相電圧とＣ相電圧との位相差、Ｃ相電圧とＡ相電圧との位相差の少なくとも１つの位相差が１２０°とならないことをいう。 (About voltage imbalance)
In a distribution line in which the load is managed to be balanced to some extent, the increase in the voltage imbalance rate tends to be large in the main line. Therefore, the power factor determination system 40 has a power factor OA to suppress an increase in the voltage imbalance rate in the three-phase distribution line 14 when the reverse flow current Ib is supplied to the three-phase distribution line 14 that is a main line. , OB, and OC are individually determined. Voltage imbalance means that the amplitude of each line voltage is different or the phase of the line voltage is out of phase in a three-phase AC voltage in which the amplitude of each line voltage is equal and the phase of the line voltage is 120 ° different. It is. The difference between the amplitudes of the line voltages means that, for example, the voltage amplitude in the A-phase current, the voltage amplitude in the B-phase current, and the voltage amplitude in the C-phase current are different from each other. Also, the phase of the line voltage is deviated from, for example, the phase difference between the A phase voltage and the B phase voltage, the phase difference between the B phase voltage and the C phase voltage, and the phase difference between the C phase voltage and the A phase voltage. It means that at least one phase difference does not become 120 °.

配電システム１は、三相配電線１４で電圧不平衡が発生すると、柱上変圧器Ｔｒに供給される電圧が目標の電圧に対してずれてしまう。柱上変圧器Ｔｒに供給される電圧のずれが大きくなると、柱上変圧器Ｔｒに接続される負荷Ｒの誤動作が発生する恐れがある。従って、配電システム１は、三相配電線１４における電圧不平衡の値を小さくすることが望ましい。   In the power distribution system 1, when voltage imbalance occurs in the three-phase distribution line 14, the voltage supplied to the pole transformer Tr deviates from the target voltage. If the deviation of the voltage supplied to the pole transformer Tr becomes large, a malfunction of the load R connected to the pole transformer Tr may occur. Therefore, it is desirable for the power distribution system 1 to reduce the voltage imbalance value in the three-phase distribution line 14.

電圧不平衡率は、正相電圧に対する逆相電圧の割合で示される。ここで、三相配電線１４における三相配電分岐線１６との接続箇所(ノードＮ１)における電圧不平衡率をεとし、正相電圧をＶＰとし、逆相電圧をＶＮとしたとき、電圧不平衡率εは、次の式（２）で表される。正相電圧ＶＰ、逆相電圧ＶＮは、各線間電圧、すなわちＡ相配電線１４ＡとＢ相配電線１４Ｂとの電圧差、Ｂ相配電線１４ＢとＣ相配電線１４Ｃとの電圧差、及びＡ相配電線１４ＡとＣ相配電線１４Ｃとの電圧差に基づいた値であり、例えば対称座標法により算出される。 The voltage imbalance rate is expressed as a ratio of the negative phase voltage to the positive phase voltage. Here, when the voltage unbalance rate at the connection point (node N 1 ) of the three-phase distribution line 14 with the three-phase distribution branch line 16 is ε, the positive phase voltage is VP , and the reverse phase voltage is V N , The voltage imbalance rate ε is expressed by the following equation (2). The normal phase voltage V P and the reverse phase voltage V N are the line voltages, that is, the voltage difference between the A phase distribution line 14A and the B phase distribution line 14B, the voltage difference between the B phase distribution line 14B and the C phase distribution line 14C, and the A phase distribution line. It is a value based on the voltage difference between 14A and the C-phase distribution line 14C, and is calculated by, for example, a symmetric coordinate method.

ε（％）＝｜ＶＮ｜／｜ＶＰ｜・１００ ・・・（２） ε (%) = | V N | / | V P | · 100 (2)

式（２）に示すように、電圧不平衡率εは、逆相電圧ＶＮの絶対値が大きくなるほど増加する。逆相電圧ＶＮの絶対値は、その箇所に供給されるまでの配電線の線路インピーダンスの増加に伴い増加する傾向にある。線路インピーダンスは、配電線の亘長が長くなると、増加する。ここで、発電装置２０から逆潮流電流Ｉｂが供給される場合、三相配電線１４における三相配電分岐線１６との接続箇所(ノードＮ１)には、配電電流Ｉａと逆潮流電流Ｉｂとが合流して流れている。すなわち、ノードＮ１には、配電電流Ｉａの成分と逆潮流ｉｂの成分とを重ね合わせた電流が流れている。三相配電線１４は、発電装置が発電しないときに流れる配電電流Ｉａに起因して発生する三相配電線１４の電圧不平衡を抑制するように、各配電線の線間距離や接続相等が設定されている。従って、三相配電線１４における三相配電分岐線１６との接続箇所(ノードＮ１)における配電電流Ｉａ起因の電圧不平衡は発生しない。一方、発電装置２０による発電時に発生する逆潮流電流Ｉｂは、発電装置２０から三相配電分岐線１６を経由して三相配電線１４に影響を与える。三相配電分岐線１６は、発電装置が発電しないときに流れる配電電流Ｉａ起因の電圧不平衡を抑制するように、各配電線の線間距離や接続相が設定されているが、逆潮流電流Ｉｂ起因の電圧不平衡を抑制するように働かない場合がある。 As shown in Expression (2), the voltage imbalance ratio ε increases as the absolute value of the negative phase voltage V N increases. The absolute value of the negative-phase voltage V N tends to increase with increasing line impedance of the distribution line to be supplied to that point. The line impedance increases as the length of the distribution line increases. Here, when the reverse power flow current Ib is supplied from the power generator 20, the distribution current Ia and the reverse power flow current Ib are connected to the connection portion (node N 1 ) of the three-phase power distribution line 14 with the three-phase power distribution branch line 16. It is flowing together. That is, the node N 1, a current obtained by superimposing a component of components and reverse flow ib distribution current Ia flows. In the three-phase distribution line 14, the distance between the distribution lines, the connection phase, and the like are set so as to suppress the voltage imbalance of the three-phase distribution line 14 caused by the distribution current Ia flowing when the power generator does not generate power. ing. Therefore, voltage imbalance due to the distribution current Ia does not occur at the connection point (node N 1 ) of the three-phase distribution line 14 with the three-phase distribution branch line 16. On the other hand, the reverse power flow current Ib generated during power generation by the power generation apparatus 20 affects the three-phase distribution line 14 from the power generation apparatus 20 via the three-phase distribution branch line 16. In the three-phase distribution branch line 16, the line distance and connection phase of each distribution line are set so as to suppress the voltage imbalance caused by the distribution current Ia that flows when the power generator does not generate power. It may not work to suppress voltage imbalance caused by Ib.

このように、三相配電線１４は、例えば三相配電分岐線１６との接続箇所(ノードＮ１)において、発電装置２０による発電時の逆潮流電流Ｉｂに起因する逆相電圧ＶＮが高くなることにより、電圧不平衡率εが高くなるおそれがある。力率決定システム４０は、力率ＯＡ、ＯＢ、ＯＣをそれぞれ個別に決定して、三相配電分岐線１６に供給される発電装置２０からの逆潮流電力（逆潮流電流Ｉｂに対応する電力）における無効電力Ｑを各相個別に制御して、逆潮流電流Ｉｂ起因の逆相電圧ＶＮの増加を抑制する。 Thus, in the three-phase distribution line 14, for example, at the connection point (node N 1 ) with the three-phase distribution branch line 16, the reverse phase voltage V N resulting from the reverse flow current Ib at the time of power generation by the power generation device 20 becomes high. As a result, the voltage imbalance ratio ε may increase. The power factor determination system 40 individually determines the power factors OA, OB, and OC, and reverse power flow from the power generator 20 supplied to the three-phase distribution branch line 16 (power corresponding to the reverse power flow current Ib). The reactive power Q is controlled individually for each phase to suppress an increase in the reverse phase voltage V N caused by the reverse flow current Ib.

（力率決定システム）
次に、力率決定システム４０について詳細に説明する。図２は、本実施形態に係る力率決定システムの模式的なブロック図である。力率決定システム４０は、コンピュータであり、力率を決定するソフトウェアを実行することにより、力率ＯＡ、ＯＢ、ＯＣをそれぞれ個別に決定する。図２に示すように、力率決定システム４０は、電流値取得部４２と、インピーダンス取得部４４と、力率指定部４６と、電流値算出部４８と、電圧算出部５０と、不平衡率算出部５２と、力率決定部５４とを有する。また、力率決定システム４０は、オペレータからの入力を受け付ける図示しない入力部（キーボード等）と、各データを表示及び出力する図示しない出力部（表示画面など）を有する。 (Power factor determination system)
Next, the power factor determination system 40 will be described in detail. FIG. 2 is a schematic block diagram of the power factor determination system according to the present embodiment. The power factor determination system 40 is a computer, and determines the power factors OA, OB, and OC individually by executing software for determining the power factor. As shown in FIG. 2, the power factor determination system 40 includes a current value acquisition unit 42, an impedance acquisition unit 44, a power factor designation unit 46, a current value calculation unit 48, a voltage calculation unit 50, and an unbalance rate. A calculation unit 52 and a power factor determination unit 54 are included. The power factor determination system 40 includes an input unit (not shown) that receives input from the operator (not shown) and an output unit (display screen etc.) that displays and outputs each data.

電流値取得部４２は、検出部３０から、ノードＮ１において三相配電分岐線１６を流れる逆潮流電流Ｉｂの電流値の情報を取得して記憶する。電流値取得部４２が取得する逆潮流電流Ｉｂの電流値は、力率決定部５４が力率を決定する前に設定された力率である過去力率において、発電装置２０が逆潮流電流Ｉｂを出力した場合の電流値である。以下、電流値取得部４２が電流値を取得する逆潮流電流Ｉｂを、過去逆潮流電流Ｉｃと記載する。このように、電流値取得部４２は、ノードＮ１において三相配電分岐線１６を流れる過去逆潮流電流Ｉｃの電流値が検出部３０により予め検出されており、その予め検出された過去逆潮流電流Ｉｃ情報を取得するということができる。なお、過去力率は、力率決定部５４による力率の決定が一度も行われていない場合、予め定められた所定力率で設定される。この場合の過去力率（所定力率）は、各相一律で定められた値であり、本実施形態においては、０．９５であるが、これに限られず、例えば０．８５以上１以下であることが好ましい。力率決定システム４０が経時で繰り返し力率の決定を行う場合であって、今回の力率の決定の前にすでに三相毎に力率を決定していた場合、過去力率は、そのすでに決定された三相毎の力率になる。 The current value acquisition unit 42 acquires and stores information on the current value of the reverse flow current Ib flowing through the three-phase distribution branch line 16 at the node N 1 from the detection unit 30. The current value of the reverse flow current Ib acquired by the current value acquisition unit 42 is the past power factor set before the power factor determination unit 54 determines the power factor. Is the current value when. Hereinafter, the reverse flow current Ib from which the current value acquisition unit 42 acquires a current value is referred to as a past reverse flow current Ic. Thus, the current value acquisition unit 42, the node N and the current value of the last reverse flow current Ic flowing through the three-phase power distribution branch line 16 at 1 is previously detected by the detection unit 30, a previously detected past reverse flow It can be said that the current Ic information is acquired. It should be noted that the past power factor is set at a predetermined power factor that has been determined in advance when the power factor has not been determined by the power factor determination unit 54. In this case, the past power factor (predetermined power factor) is a value determined uniformly for each phase, and is 0.95 in the present embodiment, but is not limited thereto, and is, for example, 0.85 or more and 1 or less. Preferably there is. When the power factor determination system 40 repeatedly determines the power factor over time, and the power factor has already been determined for every three phases before the current power factor determination, the past power factor is already It becomes the power factor of each determined three phases.

なお、電流値取得部４２は、ノードＮ１において三相配電分岐線１６を流れる電流であれば、配電電流Ｉａと逆潮流電流Ｉｂとの両方の電流値を区別せずに取得してもよい。また、上述のように、検出部３０の位置は三相配電分岐線１６内であれば任意であるため、電流値取得部４２は、ノードＮ１に限られず、三相配電分岐線１６の任意の位置を流れる過去逆潮流電流Ｉｃの電流値情報を取得してもよい。この場合、電流値取得部４２は、検出部３０の位置とノードＮ１との間の三相配電分岐線１６のインピーダンスなどから、取得した過去逆潮流電流Ｉｃの電流値を、ノードＮ１における過去逆潮流電流Ｉｃの電流値に換算して記憶する。 The current value acquiring unit 42, if the current flowing through the three-phase power distribution branch line 16 at the node N 1, may be obtained without discriminating the current value of both the distribution current Ia and reverse flow current Ib . Further, as described above, since the position of the detection unit 30 is arbitrary as long as within the three-phase power distribution branch line 16, a current value acquiring unit 42 is not limited to the node N 1, any three-phase power distribution branch line 16 Current value information of the past reverse flow current Ic flowing through the position may be acquired. In this case, the current value acquiring unit 42, etc. the impedance of the three-phase power distribution branch line 16 between the position and the node N 1 of the detector 30, the current value of the acquired past reverse flow current Ic, at node N 1 It is converted into a current value of the past reverse flow current Ic and stored.

図３は、電流値取得部が取得した電流値の情報を示すテーブルの一例である。電流値取得部４２は、過去逆潮流電流Ｉｃの電流値を、相毎に取得する。すなわち、電流値取得部４２は、Ａ相分岐線１６Ａを流れるＡ相過去逆潮流電流ＩｃＡの電流値、Ｂ相分岐線１６Ｂを流れるＢ相過去逆潮流電流ＩｃＢの電流値、及びＣ相分岐線１６Ｃを流れるＣ相過去逆潮流電流ＩｃＣの電流値を取得し、記憶する。また、検出部３０は、過去逆潮流電流Ｉｃの電流値を、所定の時間毎に逐次検出する。電流値取得部４２は、その検出された過去逆潮流電流Ｉｃの電流値を逐次取得し、記憶する。また、電流値取得部４２は、その過去逆潮流電流Ｉｃが検出された際の発電装置２０の外部環境の情報を取得し、その外部環境と過去逆潮流電流Ｉｃの電流値とを関連付けて記憶する。発電装置２０の外部環境とは、発電装置２０の発電量に影響を及ぼす発電装置２０の周囲の環境であり、例えば、晴れや曇りなどの気候、又は季節などである。具体的には、電流値取得部４２は、図３に示すように、Ａ相過去逆潮流電流ＩｃＡの電流値と、Ｂ相過去逆潮流電流ＩｃＢの電流値と、Ｃ相過去逆潮流電流ＩｃＣの電流値とを、過去逆潮流電流Ｉｃが検出された際の発電装置２０の外部環境の情報と関連付けて、所定の時間（図３の例では１時間）毎に記憶する。図３の例では、外部環境が晴れである日の０時では、Ａ相過去逆潮流電流ＩｃＡの電流値がＩｃＡ０であり、Ｂ相過去逆潮流電流ＩｃＢの電流値がＩｃＢ０であり、Ｃ相過去逆潮流電流ＩｃＣの電流値ＩｃＣ０である。そして、同日の１時では、Ａ相過去逆潮流電流ＩｃＡの電流値がＩｃＡ１であり、Ｂ相過去逆潮流電流ＩｃＢの電流値がＩｃＢ１であり、Ｃ相過去逆潮流電流ＩｃＣの電流値ＩｃＣ１である。また、同日の２３時では、Ａ相過去逆潮流電流ＩｃＡの電流値がＩｃＡ２３であり、Ｂ相過去逆潮流電流ＩｃＢの電流値がＩｃＢ２３であり、Ｃ相過去逆潮流電流ＩｃＣの電流値ＩｃＣ２３である。なお、図３のテーブルは、１日分のテーブルであるが、それに限られず、例えば連続した複数日のテーブルであってもよい。また、図３のテーブルでは、外部環境が１日中同じ晴れであったが、外部環境の変化に応じて、１日の中で外部環境を変更してもよい。 FIG. 3 is an example of a table showing information on current values acquired by the current value acquisition unit. The current value acquisition unit 42 acquires the current value of the past reverse flow current Ic for each phase. That is, the current value acquisition unit 42 determines the current value of the A-phase past reverse flow current IcA flowing through the A-phase branch line 16A, the current value of the B-phase past reverse flow current IcB flowing through the B-phase branch line 16B, and the C-phase branch line. The current value of the C-phase past reverse flow current IcC flowing through 16C is acquired and stored. Further, the detection unit 30 sequentially detects the current value of the past reverse flow current Ic every predetermined time. The current value acquisition unit 42 sequentially acquires and stores the detected current value of the past reverse flow current Ic. In addition, the current value acquisition unit 42 acquires information on the external environment of the power generation device 20 when the past reverse flow current Ic is detected, and stores the external environment and the current value of the past reverse flow current Ic in association with each other. To do. The external environment of the power generation apparatus 20 is an environment around the power generation apparatus 20 that affects the amount of power generated by the power generation apparatus 20, for example, a climate such as sunny or cloudy, or a season. Specifically, as shown in FIG. 3, the current value acquisition unit 42, the current value of the A-phase past reverse flow current IcA, the current value of the B-phase past reverse flow current IcB, and the C-phase past reverse flow current IcC Is associated with information on the external environment of the power generation apparatus 20 when the past reverse flow current Ic is detected, and is stored every predetermined time (1 hour in the example of FIG. 3). In the example of FIG. 3, at 0 o'clock on a day when the external environment is clear, the current value of the A-phase past reverse flow current IcA is IcA 0 , and the current value of the B-phase past reverse flow current IcB is IcB 0 . This is the current value IcC 0 of the C-phase past reverse flow current IcC. At 1 o'clock on the same day, the current value of the A-phase past reverse flow current IcA is IcA 1 , the current value of the B-phase past reverse flow current IcB is IcB 1 , and the current value of the C-phase past reverse flow current IcC. IcC 1 . At 23:00 on the same day, the current value of the A-phase past reverse flow current IcA is IcA 23 , the current value of the B-phase past reverse flow current IcB is IcB 23 , and the current value of the C-phase past reverse flow current IcC. IcC 23 . The table in FIG. 3 is a table for one day, but is not limited thereto, and may be a table for a plurality of consecutive days, for example. In the table of FIG. 3, the external environment is the same and clear all day, but the external environment may be changed during the day according to a change in the external environment.

このように、電流値取得部４２は、過去逆潮流電流Ｉｃの電流値を取得するが、例えば検出部３０が他の情報も併せて取得している場合、その他の情報も取得してよい。電流値取得部４２は、例えば、ノードＮ１における各分岐線の電圧値や力率等も併せて取得してよい。 As described above, the current value acquisition unit 42 acquires the current value of the past reverse flow current Ic. For example, when the detection unit 30 also acquires other information, other information may be acquired. Current value acquiring unit 42, for example, may be obtained also to the voltage value and the power factor of each branch line at the node N 1.

図２に示すインピーダンス取得部４４は、三相配電分岐線１６のインピーダンスの情報を取得する。より具体的には、インピーダンス取得部４４は、発電装置２０との接続箇所とノードＮ１（三相配電線１４との接続箇所）との間におけるＡ相分岐線１６ＡとＢ相分岐線１６ＢとＣ相分岐線１６Ｃとのインピーダンスの情報を取得する。インピーダンス取得部４４は、三相配電分岐線１６のインピーダンスを、三相配電分岐線１６の各配電線の線路定数と、三相配電分岐線１６の各配電線同士の位置関係とに基づき算出する。線路定数とは、単位長あたりの配電線のインピーダンス（抵抗、リアクタンス、及び静電容量）のことをいう。インピーダンス取得部４４は、線路定数を、例えば発電装置２０との接続箇所から三相配電線１４との接続箇所までの三相配電分岐線１６の長さ、線の太さ等から算出する。インピーダンス取得部４４は、この線路定数からインピーダンスを算出する。 The impedance acquisition unit 44 illustrated in FIG. 2 acquires information on the impedance of the three-phase distribution branch line 16. More specifically, the impedance acquisition unit 44 includes the A-phase branch line 16A, the B-phase branch line 16B, and C between the connection point with the power generation device 20 and the node N 1 (connection point with the three-phase distribution line 14). Information on impedance with the phase branch line 16C is acquired. The impedance acquisition unit 44 calculates the impedance of the three-phase distribution branch line 16 based on the line constant of each distribution line of the three-phase distribution branch line 16 and the positional relationship between the distribution lines of the three-phase distribution branch line 16. . The line constant refers to the impedance (resistance, reactance, and capacitance) of the distribution line per unit length. The impedance acquisition unit 44 calculates the line constant from, for example, the length of the three-phase distribution branch line 16 from the connection point with the power generation device 20 to the connection point with the three-phase distribution line 14, the thickness of the line, and the like. The impedance acquisition unit 44 calculates the impedance from this line constant.

また、三相配電分岐線１６の各配電線同士の位置関係とは、Ａ相分岐線１６ＡとＢ相分岐線１６Ｂとの間の距離、Ｂ相分岐線１６ＢとＣ相分岐線１６Ｃとの間の距離、及びＡ相分岐線１６ＡとＣ相分岐線１６Ｃとの間の距離をいう。Ａ相分岐線１６Ａは、Ｂ相分岐線１６Ｂからの距離及びＣ相分岐線１６Ｃからの距離によって相互リアクタンスの値が変化する。Ｂ相分岐線１６Ｂ及びＣ相分岐線１６Ｃも同様に、他の分岐線からの距離によって相互リアクタンスの値が変化する。相互リアクタンスは、三相配電分岐線１６のインピーダンスの一部であるため、インピーダンス取得部４４は、三相配電分岐線１６の各配電線同士の位置関係から相互リアクタンスを算出し、それを基にインピーダンスを算出する。このように相互リアクタンスを含めたインピーダンスから電圧不平衡値を算出することで、相互リアクタンスを考慮した力率の決定を行うことができる。従って、この場合、非対称性から発生する電圧不平衡を抑制することが可能となり、例えば三相配電分岐線１６をねん架するというような工事が不要となる。   Further, the positional relationship between the distribution lines of the three-phase distribution branch line 16 is the distance between the A-phase branch line 16A and the B-phase branch line 16B, and between the B-phase branch line 16B and the C-phase branch line 16C. And the distance between the A-phase branch line 16A and the C-phase branch line 16C. The value of the mutual reactance of the A-phase branch line 16A varies depending on the distance from the B-phase branch line 16B and the distance from the C-phase branch line 16C. Similarly, the values of the mutual reactances of the B-phase branch line 16B and the C-phase branch line 16C vary depending on the distance from the other branch lines. Since the mutual reactance is a part of the impedance of the three-phase distribution branch line 16, the impedance acquisition unit 44 calculates the mutual reactance from the positional relationship between the distribution lines of the three-phase distribution branch line 16, and based on that. Calculate the impedance. Thus, by calculating the voltage unbalance value from the impedance including the mutual reactance, the power factor can be determined in consideration of the mutual reactance. Therefore, in this case, it is possible to suppress the voltage imbalance that occurs due to asymmetry, and for example, a construction of suspending the three-phase distribution branch line 16 becomes unnecessary.

図４及び図５は、装柱の例を示す図である。装柱とは、Ａ相分岐線１６ＡとＢ相分岐線１６ＢとＣ相分岐線１６Ｃとの配列パターンである。図４は、三相配電分岐線１６が水平方向に配列した水平装柱を示している。図５は、三相配電分岐線１６が垂直方向に配列した水平装柱を示している。図４及び図５に示すように、三相配電分岐線１６の各配電線同士の距離は、装柱の種類と、各分岐線の配列順によって決まる。各分岐線の配列順とは、どの順でＡ相分岐線１６ＡとＢ相分岐線１６ＢとＣ相分岐線１６Ｃとが配列しているかを示す情報である。図４の水平装柱の例では、Ａ相分岐線１６ＡとＢ相分岐線１６ＢとＣ相分岐線１６Ｃとが、左からこの配列順で配列している。インピーダンス取得部４４は、例えばオペレータの入力により装柱の種類の情報を取得し、それに基づき三相配電分岐線１６の各配電線同士の距離を算出する。ただし、インピーダンス取得部４４は、装柱の種類でなく、各配電線同士の距離を取得するものであれば、装柱の情報から算出するものでなくてもよい。なお、装柱の種類は、図４、及び図５に示すものに限られず、例えば、片槍装柱、心付装柱、正三角装柱なども挙げられる。   4 and 5 are diagrams showing examples of the pillars. The column is an arrangement pattern of the A-phase branch line 16A, the B-phase branch line 16B, and the C-phase branch line 16C. FIG. 4 shows a horizontal column with three-phase distribution branch lines 16 arranged in the horizontal direction. FIG. 5 shows a horizontal column with three-phase distribution branch lines 16 arranged in the vertical direction. As shown in FIG.4 and FIG.5, the distance of each distribution line of the three-phase distribution branch line 16 is decided by the kind of column and the arrangement order of each branch line. The order of arrangement of the branch lines is information indicating in which order the A-phase branch line 16A, the B-phase branch line 16B, and the C-phase branch line 16C are arranged. In the example of the horizontal column in FIG. 4, the A-phase branch line 16A, the B-phase branch line 16B, and the C-phase branch line 16C are arranged in this arrangement order from the left. The impedance acquisition unit 44 acquires, for example, information on the type of the pillar by an operator input, and calculates the distance between the distribution lines of the three-phase distribution branch line 16 based on the information. However, the impedance acquisition unit 44 does not have to calculate from the information on the pillars as long as it acquires the distance between the distribution lines instead of the type of pillars. In addition, the kind of mounting column is not restricted to what is shown in FIG.4 and FIG.5, For example, a single-sided mounting column, a centering mounting column, a regular triangular mounting column etc. are mentioned.

図２に示す力率指定部４６は、発電装置２０が三相配電分岐線１６に逆潮流電流Ｉｂを供給する際の力率を、三相毎にそれぞれ所定の値である指定力率に指定する。指定力率は、不平衡率算出部５２による不平衡率の算出のために用いられる力率の値である。具体的には、力率指定部４６は、発電装置２０がＡ相分岐線１６ＡにＡ相逆潮流電流ＩｂＡを供給する際の力率を、指定力率ＯＡＸに指定する。力率指定部４６は、発電装置２０がＢ相分岐線１６ＢにＢ相逆潮流電流ＩｂＢを供給する際の力率を、指定力率ＯＢＸに指定する。力率指定部４６は、発電装置２０がＣ相分岐線１６ＣにＣ相逆潮流電流ＩｂＣを供給する際の力率を、指定力率ＯＣＸに指定する。 The power factor designating unit 46 shown in FIG. 2 designates the power factor when the power generator 20 supplies the reverse power flow current Ib to the three-phase distribution branch line 16 as a designated power factor that is a predetermined value for each of the three phases. To do. The designated power factor is a power factor value used for calculation of the unbalance rate by the unbalance rate calculation unit 52. Specifically, the power factor designating unit 46 designates the designated power factor OA X as the power factor when the power generation apparatus 20 supplies the A-phase reverse flow current IbA to the A-phase branch line 16A. The power factor designating unit 46 designates the designated power factor OB X as the power factor when the power generator 20 supplies the B-phase reverse flow current IbB to the B-phase branch line 16B. The power factor designating unit 46 designates the power factor when the power generation apparatus 20 supplies the C-phase reverse flow current IbC to the C-phase branch line 16C as the designated power factor OC X.

力率指定部４６は、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの平均値が、予め定められた所定の平均力率値となるように、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸをそれぞれ指定する。さらに、力率指定部４６は、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸのそれぞれが、所定数値範囲内になるように、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸをそれぞれ指定する。本実施形態における平均力率値は、上記の所定力率、すなわち０．９５であるが、これに限られず、例えば０．８以上１以下であることが好ましいが、その数値範囲に限られず、任意に設定してよい。また、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの予め定められた数値範囲は、０．８５以上１以下であるが、これに限られず、任意の数値範囲であってもよい。 The power factor designating unit 46 sets the designated power factors OA X , OB X , OC X so that the average value of the designated power factors OA X , OB X , OC X becomes a predetermined average power factor value. Specify each. Furthermore, the power factor designating unit 46 designates the designated power factors OA X , OB X , and OC X so that the designated power factors OA X , OB X , and OC X are within a predetermined numerical range. The average power factor value in the present embodiment is the above-mentioned predetermined power factor, that is, 0.95, but is not limited thereto, and is preferably 0.8 or more and 1 or less, but is not limited to the numerical range, It may be set arbitrarily. Further, the predetermined numerical range of the designated power factors OA X , OB X , and OC X is 0.85 or more and 1 or less, but is not limited thereto, and may be an arbitrary numerical range.

図２に示す電流値算出部４８は、電流値取得部４２が取得した過去逆潮流電流Ｉｃの値と、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸとに基づき、指定逆潮流電流値Ｉｄを算出する。指定逆潮流電流値Ｉｄは、発電装置２０が三相配電分岐線１６に逆潮流電流Ｉｂを供給する際の力率が指定力率ＯＡＸ、ＯＢＸ、ＯＣＸであると仮定した場合に、三相配電分岐線１６のノードＮ１（三相配電線１４との接続箇所）に流れる逆潮流電流Ｉｂである。電流値算出部４８は、過去逆潮流電流Ｉｃが検出された際の力率を、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸにおきかえることで、指定逆潮流電流値Ｉｄの値を算出する。具体的には、電流値算出部４８は、Ａ相過去逆潮流電流ＩｃＡが検出された際の力率を指定力率ＯＡＸに置き換えて、力率を指定力率ＯＡＸと仮定した場合にＡ相分岐線１６Ａを流れるＡ相指定逆潮流電流値ＩｄＡの電流値を算出する。また、電流値算出部４８は、Ｂ相過去逆潮流電流ＩｃＢが検出された際の力率を指定力率ＯＢＸに置き換えて、力率を指定力率ＯＢＸと仮定した場合にＢ相分岐線１６Ｂを流れるＢ相指定逆潮流電流値ＩｄＢの電流値を算出する。電流値算出部４８は、Ｃ相過去逆潮流電流ＩｃＣが検出された際の力率を指定力率ＯＣＸに置き換えて、力率を指定力率ＯＣＸと仮定した場合にＣ相分岐線１６Ｃを流れるＣ相指定逆潮流電流値ＩｄＣの電流値を算出する。 The current value calculation unit 48 illustrated in FIG. 2 calculates the specified reverse flow current value Id based on the past reverse flow current Ic value acquired by the current value acquisition unit 42 and the specified power factors OA X , OB X , OC X. calculate. The designated reverse flow current value Id is obtained when it is assumed that the power factor when the power generator 20 supplies the reverse flow current Ib to the three-phase distribution branch line 16 is the designated power factor OA X , OB X , OC X. This is a reverse power flow current Ib that flows through the node N 1 of the three-phase distribution branch line 16 (the connection point with the three-phase distribution line 14). The current value calculation unit 48 calculates the value of the designated reverse flow current value Id by replacing the power factor when the past reverse flow current Ic is detected with the designated power factors OA X , OB X , OC X. Specifically, the current value calculation unit 48 replaces the power factor when A-phase past the reverse flow current IcA is detected in the specified power factor OA X, in assuming a power factor and the specified power factor OA X The current value of the A-phase specified reverse flow current value IdA flowing through the A-phase branch line 16A is calculated. The current value calculating unit 48 replaces the power factor when B-phase past the reverse flow current IcB is detected in the specified power factor OB X, B phase, assuming a power factor and the specified power factor OB X branch The current value of the B-phase specified reverse flow current value IdB flowing through the line 16B is calculated. Current value calculating unit 48 replaces the power factor when the C-phase past the reverse flow current IcC is detected in the specified power factor OC X, C-phase branch line 16C, assuming a power factor and the specified power factor OC X The current value of the C-phase specified reverse flow current value IdC flowing through is calculated.

電流値算出部４８は、電流値取得部４２が取得した過去逆潮流電流Ｉｃの値毎、すなわち発電装置２０の外部環境及び時間毎の指定逆潮流電流値Ｉｄの値を算出する。   The current value calculation unit 48 calculates the value of the past reverse flow current Ic acquired by the current value acquisition unit 42, that is, the value of the designated reverse flow current value Id for each external environment and time of the power generation device 20.

図２に示す電圧算出部５０は、電流値算出部４８が算出した指定逆潮流電流値Ｉｄの値と、インピーダンス取得部４４が取得した三相配電分岐線１６のインピーダンスとに基づき、潮流計算によって、指定逆潮流電圧値を三相毎に算出する。指定逆潮流電圧値は、発電装置２０が三相配電分岐線１６に逆潮流電流Ｉｂを供給する際の力率が指定力率ＯＡＸ、ＯＢＸ、ＯＣＸであると仮定した場合での、三相配電分岐線１６のノードＮ１（三相配電線１４との接続箇所）における電圧値である。三相配電分岐線１６のノードＮ１における電圧値は、ノードＮ１よりも逆潮流電流Ｉｂの流れにおいて上流である発電装置２０との接続箇所からノードＮ１までの間のインピーダンスと、ノードＮ１での電流値とに基づき算出することができる。具体的には、電圧算出部５０は、Ａ相指定逆潮流電流値ＩｄＡとＡ相分岐線１６Ａのインピーダンスとに基づき、指定力率ＯＡＸと仮定した場合のノードＮ１におけるＡ相分岐線１６Ａでの指定逆潮流電圧値を算出する。同様に、電圧算出部５０は、Ｂ相指定逆潮流電流値ＩｄＢとＢ相分岐線１６Ｂのインピーダンスとに基づき、指定力率ＯＢＸと仮定した場合のノードＮ１におけるＢ相分岐線１６Ｂでの指定逆潮流電圧値を算出する。同様に、電圧算出部５０は、Ｃ相指定逆潮流電流値ＩｄＣとＣ相分岐線１６Ｃのインピーダンスとに基づき、指定力率ＯＣＸと仮定した場合のノードＮ１におけるＣ相分岐線１６Ｃでの指定逆潮流電圧値を算出する。 The voltage calculation unit 50 shown in FIG. 2 performs a power flow calculation based on the value of the designated reverse flow current value Id calculated by the current value calculation unit 48 and the impedance of the three-phase distribution branch line 16 acquired by the impedance acquisition unit 44. The specified reverse power flow voltage value is calculated for every three phases. The specified reverse power flow voltage value is based on the assumption that the power factor when the power generator 20 supplies the reverse power flow current Ib to the three-phase distribution branch line 16 is the specified power factor OA X , OB X , OC X. It is the voltage value at the node N 1 of the three-phase distribution branch line 16 (connection point with the three-phase distribution line 14). Voltage value at the node N 1 of the three-phase power distribution branch line 16, the impedance between the connecting portion between the power generating device 20 is upstream in the flow of reverse flow current Ib than the node N 1 to node N 1, the node N 1 based on the current value at 1 . Specifically, the voltage calculation unit 50, based on the impedance of the A-phase specified reverse flow current IdA the A-phase branch line 16A, the A-phase branch lines 16A at node N 1 on the assumption that the specified power factor OA X Calculate the specified reverse power flow voltage value at. Similarly, the voltage calculation unit 50, based on the impedance of the B-phase specified reverse flow current IdB and B-phase branch line 16B, in the B-phase branch line 16B at node N 1 on the assumption that the specified power factor OB X Calculate the specified reverse power flow voltage value. Similarly, the voltage calculation unit 50, based on the impedance of the C-phase specified reverse flow current IdC and C-phase branch line 16C, at the C-phase branch line 16C at node N 1 on the assumption that the specified power factor OC X Calculate the specified reverse power flow voltage value.

電圧算出部５０は、電流値算出部４８が算出した発電装置２０の外部環境及び時間毎の指定逆潮流電流値Ｉｄの値に対応して、発電装置２０の外部環境及び時間毎の指定逆潮流電圧値の値を算出する。   The voltage calculation unit 50 corresponds to the external environment of the power generation device 20 calculated by the current value calculation unit 48 and the value of the designated reverse flow current value Id for each hour, and the designated reverse flow for the external environment of the power generation device 20 and each time. Calculate the voltage value.

図２に示す不平衡率算出部５２は、電圧算出部５０が算出した三相配電分岐線１６（Ａ相分岐線１６Ａ、Ｂ相分岐線１６Ｂ、Ｃ相分岐線１６Ｃ）における指定逆潮流電圧値から、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸであると仮定した場合のノードＮ１（三相配電分岐線１６との接続箇所）における三相配電線１４の電圧不平衡率を算出する。不平衡率算出部５２は、電圧算出部５０が算出した発電装置２０の外部環境及び時間毎の全ての指定逆潮流電圧値に対応した電圧不平衡率を算出する。不平衡率算出部５２は、その中で最も値が高い電圧不平衡率の値を、力率決定部５４に出力する。 The unbalance rate calculation unit 52 shown in FIG. 2 is a designated reverse power flow voltage value in the three-phase distribution branch line 16 (A phase branch line 16A, B phase branch line 16B, C phase branch line 16C) calculated by the voltage calculation unit 50. From this, the voltage unbalance rate of the three-phase distribution line 14 at the node N 1 (the connection point with the three-phase distribution branch line 16) when it is assumed that the designated power factors OA X , OB X , and OC X are calculated. The unbalance rate calculation unit 52 calculates the voltage unbalance rate corresponding to all the specified reverse power flow voltage values for each external environment and time calculated by the voltage calculation unit 50. The unbalance rate calculation unit 52 outputs the voltage unbalance rate value having the highest value to the power factor determination unit 54.

力率決定部５４は、不平衡率算出部５２が算出した電圧不平衡率に基づき、Ａ相逆潮流電流ＩｂＡに対応する電力をＡ相分岐線１６Ａに供給する際の力率ＯＡと、Ｂ相逆潮流電流ＩｂＢに対応する電力をＢ相分岐線１６Ｂに供給する際の力率ＯＢと、Ｃ相逆潮流電流ＩｂＣに対応する電力をＣ相分岐線１６Ｃに供給する際の力率ＯＣとを決定する。具体的には、力率指定部４６と電流値算出部４８と電圧算出部５０と不平衡率算出部５２とは、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの値を変化させながらそれぞれの処理を繰り替えし、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの値毎の電圧不平衡率を算出する。力率決定部５４は、この中で電圧不平衡率が最小となった指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを、それぞれ力率ＯＡ、ＯＢ、ＯＣに決定する。ただし、力率決定部５４は、不平衡率算出部５２が算出した電圧不平衡率が所定の閾値以下である場合に、その場合の指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを、それぞれ力率ＯＡ、ＯＢ、ＯＣに決定すればよい。この場合、力率指定部４６と電流値算出部４８と電圧算出部５０と不平衡率算出部５２とは、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの値を変化させながらそれぞれの処理を繰り替えさなくてもよい。 Based on the voltage unbalance rate calculated by the unbalance rate calculation unit 52, the power factor determination unit 54 supplies the power factor OA when supplying power corresponding to the A-phase reverse flow current IbA to the A-phase branch line 16A, and B Power factor OB when supplying power corresponding to the phase reverse flow current IbB to the B phase branch line 16B, and power factor OC when supplying power corresponding to the C phase reverse flow current IbC to the C phase branch line 16C To decide. Specifically, the power factor specifying unit 46, the current value calculating unit 48, the voltage calculating unit 50, and the unbalance rate calculating unit 52 change the values of the specified power factors OA X , OB X , and OC X , respectively. The process is repeated to calculate the voltage imbalance rate for each value of the designated power factor OA X , OB X , OC X. The power factor determination unit 54 determines the designated power factors OA X , OB X , and OC X in which the voltage imbalance rate is minimum among these as the power factors OA, OB, and OC, respectively. However, when the voltage unbalance rate calculated by the unbalance rate calculation unit 52 is equal to or less than a predetermined threshold, the power factor determination unit 54 converts the designated power factors OA X , OB X , and OC X to the power The rates OA, OB, and OC may be determined. In this case, the power factor specifying unit 46, the current value calculating unit 48, the voltage calculating unit 50, and the unbalance rate calculating unit 52 perform the respective processes while changing the values of the specified power factors OA X , OB X , and OC X. It does not have to be repeated.

力率決定部５４は、この決定した力率ＯＡ、ＯＢ、ＯＣの値の情報を、発電装置２０の出力制御部２４に出力する。ただし、力率決定部５４は、決定した力率ＯＡ、ＯＢ、ＯＣの値の情報を出力制御部２４に出力しなくてもよく、例えばオペレータが、決定した力率ＯＡ、ＯＢ、ＯＣの値の情報を、発電装置２０の管理者に伝達してもよい。   The power factor determination unit 54 outputs information on the determined values of the power factors OA, OB, and OC to the output control unit 24 of the power generation apparatus 20. However, the power factor determination unit 54 does not need to output the determined power factor OA, OB, OC value information to the output control unit 24. For example, the operator determines the power factor OA, OB, OC value. This information may be transmitted to the administrator of the power generation apparatus 20.

（出力制御部）
次に、図１に示す発電装置２０の出力制御部２４について説明する。図６は、本実施形態に係る出力制御部の構成を模式的に示すブロック図である。図６に示すように、出力制御部２４は、コンバータ部２６と、力率制御部２８とを有する。コンバータ部２６は、発電部２２が発電した直流電力が入力され、それを三相交流電力に変換するコンバータである。力率制御部２８は、無効電力量を制御する無効電力制御装置である。力率制御部２８は、力率決定部５４が決定した力率ＯＡ、ＯＢ、ＯＣの値を取得する。力率制御部２８は、力率ＯＡ、ＯＢ、ＯＣとなるように、コンバータ部２６が変換して生成した三相交流電力の無効電力値を三相毎に制御する。力率制御部２８によって力率ＯＡ、ＯＢ、ＯＣとなるように変換された三相交流電力は、対応する電圧下での逆潮流電流Ｉｂとして、三相配電分岐線１６に出力される。 (Output control unit)
Next, the output control part 24 of the electric power generating apparatus 20 shown in FIG. 1 is demonstrated. FIG. 6 is a block diagram schematically showing the configuration of the output control unit according to the present embodiment. As shown in FIG. 6, the output control unit 24 includes a converter unit 26 and a power factor control unit 28. The converter unit 26 is a converter that receives DC power generated by the power generation unit 22 and converts it into three-phase AC power. The power factor control unit 28 is a reactive power control device that controls the amount of reactive power. The power factor control unit 28 acquires values of the power factors OA, OB, and OC determined by the power factor determination unit 54. The power factor control unit 28 controls the reactive power value of the three-phase AC power generated by conversion by the converter unit 26 for each of the three phases so that the power factors OA, OB, and OC are obtained. The three-phase AC power converted to have power factors OA, OB, and OC by the power factor control unit 28 is output to the three-phase distribution branch line 16 as a reverse power flow current Ib under a corresponding voltage.

（制御フロー）
次に、力率決定システム４０による力率を決定するための制御フローと、出力制御部２４による力率の制御フローとを説明する。図７は、本実施形態に係る力率の決定フローを説明するフローチャートである。図７に示すように、最初に、力率決定システム４０は、電流値取得部４２により、予め検出されたノードＮ１において三相配電分岐線１６を流れる過去逆潮流電流Ｉｃの電流値を、三相毎に取得する（ステップＳ１０）。電流値取得部４２は、例えば図３に示すように、過去逆潮流電流Ｉｃの電流値を、過去逆潮流電流Ｉｃが検出された際の発電装置２０の外部環境の情報と関連付けて、所定の時間毎に取得して記憶する。そして、力率決定システム４０は、インピーダンス取得部４４により、三相配電分岐線１６のインピーダンスを、三相毎に取得する（ステップＳ１２）。具体的には、インピーダンス取得部４４は、三相配電分岐線１６のインピーダンスを、三相配電分岐線１６の各配電線の線路定数と、三相配電分岐線１６の各配電線同士の位置関係とに基づき算出する。 (Control flow)
Next, a control flow for determining the power factor by the power factor determination system 40 and a power factor control flow by the output control unit 24 will be described. FIG. 7 is a flowchart for explaining a power factor determination flow according to this embodiment. As shown in FIG. 7, first, the power factor determination system 40 calculates the current value of the past reverse power flow current Ic flowing through the three-phase distribution branch line 16 at the node N 1 detected in advance by the current value acquisition unit 42. Obtained for each of the three phases (step S10). For example, as illustrated in FIG. 3, the current value acquisition unit 42 associates the current value of the past reverse flow current Ic with information on the external environment of the power generation device 20 when the past reverse flow current Ic is detected, Acquire and store every hour. And the power factor determination system 40 acquires the impedance of the three-phase distribution branch line 16 for every three phases by the impedance acquisition part 44 (step S12). Specifically, the impedance acquisition unit 44 determines the impedance of the three-phase distribution branch line 16, the line constant of each distribution line of the three-phase distribution branch line 16, and the positional relationship between the distribution lines of the three-phase distribution branch line 16. Based on and.

そして、力率決定システム４０は、力率指定部４６により、三相毎に指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを指定する（ステップＳ１４）。具体的には、力率指定部４６は、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの平均値が所定の平均力率値になり、かつ、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸのそれぞれが所定の数値範囲内になるように、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸをそれぞれ指定する。 Then, the power factor determination system 40 designates the designated power factors OA X , OB X , and OC X for each of the three phases by the power factor designation unit 46 (step S14). Specifically, the power factor designating unit 46 determines that the average value of the designated power factors OA X , OB X , OC X becomes a predetermined average power factor value, and the designated power factors OA X , OB X , OC X Designated power factors OA X , OB X , and OC X are designated so that each is within a predetermined numerical range.

指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを指定した後、力率決定システム４０は、電流値算出部４８により、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸと過去逆潮流電流Ｉｃの電流値とから、指定逆潮流電流値Ｉｄを、三相毎に算出する（ステップＳ１６）。指定逆潮流電流値Ｉｄは、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸであると仮定した場合に三相配電分岐線１６のノードＮ１に流れる逆潮流電流Ｉｂである。電流値算出部４８は、過去逆潮流電流Ｉｃが検出された際の力率を、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸにおきかえることで、指定逆潮流電流値Ｉｄの値を算出する。電流値算出部４８は、発電装置２０の外部環境及び時間毎の指定逆潮流電流値Ｉｄの値を算出する。 After designating the designated power factors OA X , OB X , and OC X , the power factor determination system 40 uses the current value calculation unit 48 to specify the current values of the designated power factors OA X , OB X , OC X and the past reverse flow current Ic. Then, the designated reverse flow current value Id is calculated for each of the three phases (step S16). The designated reverse flow current value Id is the reverse flow current Ib that flows through the node N 1 of the three-phase distribution branch line 16 when it is assumed that the designated power factors OA X , OB X , and OC X. The current value calculation unit 48 calculates the value of the designated reverse flow current value Id by replacing the power factor when the past reverse flow current Ic is detected with the designated power factors OA X , OB X , OC X. The current value calculation unit 48 calculates the value of the designated reverse flow current value Id for each external environment and time of the power generation device 20.

指定逆潮流電流値Ｉｄを算出した後、力率決定システム４０は、電圧算出部５０により、指定逆潮流電流値Ｉｄと三相配電分岐線１６のインピーダンスとから、指定逆潮流電圧値を三相毎に算出する（ステップＳ１８）。指定逆潮流電圧値は、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸであると仮定した場合での、三相配電分岐線１６のノードＮ１における電圧値である。電圧算出部５０は、潮流計算により、指定逆潮流電圧値を三相毎に算出する。電圧算出部５０は、発電装置２０の外部環境及び時間毎の指定逆潮流電圧値を算出する。 After calculating the designated reverse flow current value Id, the power factor determination system 40 uses the voltage calculation unit 50 to calculate the designated reverse flow current voltage value from the designated reverse flow current value Id and the impedance of the three-phase distribution branch line 16 in three phases. It is calculated every time (step S18). The designated reverse power flow voltage value is a voltage value at the node N 1 of the three-phase distribution branch line 16 when it is assumed that the designated power factors OA X , OB X , and OC X are used. The voltage calculation unit 50 calculates a specified reverse power flow voltage value for every three phases by power flow calculation. The voltage calculation unit 50 calculates a specified reverse power flow voltage value for each external environment and time of the power generation apparatus 20.

指定逆潮流電圧値を算出した後、力率決定システム４０は、不平衡率算出部５２により、指定逆潮流電圧値から、電圧不平衡率を算出する（ステップＳ２０）。具体的には、不平衡率算出部５２は、指定逆潮流電圧値から、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸであると仮定した場合のノードＮ１における三相配電線１４での電圧不平衡率を算出する。不平衡率算出部５２は、発電装置２０の外部環境及び時間毎の全ての指定逆潮流電圧値に対応した電圧不平衡率を算出する。不平衡率算出部５２は、その中で最も値が高いものを、電圧不平衡率として選択する。 After calculating the designated reverse flow voltage value, the power factor determination system 40 calculates the voltage unbalance rate from the designated reverse flow voltage value by the unbalance rate calculation unit 52 (step S20). Specifically, the unbalance rate calculation unit 52 determines the voltage imbalance in the three-phase distribution line 14 at the node N 1 when it is assumed that the designated power factor OA X , OB X , OC X is obtained from the designated reverse power flow voltage value. Calculate the equilibrium rate. The unbalance rate calculation unit 52 calculates the voltage unbalance rate corresponding to the external environment of the power generation apparatus 20 and all the specified reverse power flow voltage values for each time. The unbalance rate calculator 52 selects the highest value among them as the voltage unbalance rate.

電圧不平衡率を算出した後、力率決定システム４０は、全ての指定力率の組み合わせを選択したか判断する（ステップＳ２２）。すなわち、力率指定部４６は、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの平均値が所定の平均力率値になり、かつ、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸのそれぞれが所定の数値範囲内になるような指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの数値の組み合わせを、全て選択して指定したかを判断する。全ての指定力率の組み合わせを選択していない場合（ステップＳ２２；Ｎｏ）、ステップＳ１４に戻り、他の数値の組み合わせであって、平均値が所定の平均力率値になり、かつ、それぞれが所定の数値範囲内になるような指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを指定して、その指定力率における電圧不平衡率を算出する。 After calculating the voltage imbalance rate, the power factor determination system 40 determines whether all combinations of designated power factors have been selected (step S22). In other words, the power factor designating unit 46 sets the average value of the designated power factors OA X , OB X , and OC X to a predetermined average power factor value, and each of the designated power factors OA X , OB X , and OC X is predetermined. It is determined whether all combinations of numerical values of designated power factors OA X , OB X , and OC X that fall within the numerical value range are selected and designated. If all combinations of designated power factors have not been selected (step S22; No), the process returns to step S14, which is a combination of other numerical values, the average value becomes a predetermined average power factor value, and each Designated power factors OA X , OB X , and OC X that fall within a predetermined numerical range are designated, and a voltage imbalance rate at the designated power factor is calculated.

全ての指定力率の組み合わせを選択した場合（ステップＳ２２；Ｙｅｓ）、力率決定システム４０は、力率決定部５４が、不平衡率算出部５２によって算出された最小の電圧不平衡率となる場合の指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを、力率ＯＡ、ＯＢ、ＯＣとして決定する(ステップＳ２４)。ステップＳ２４での力率ＯＡ、ＯＢ、ＯＣの決定により、この処理は終了する。 When all combinations of designated power factors are selected (step S22; Yes), in the power factor determination system 40, the power factor determination unit 54 has the minimum voltage unbalance rate calculated by the unbalance rate calculation unit 52. In this case, the designated power factors OA X , OB X , and OC X are determined as the power factors OA, OB, and OC (step S24). This process is completed by determining the power factors OA, OB, and OC in step S24.

なお、不平衡率算出部５２は、現在の外部環境及び時刻を検出して、それと合致する環境及び時刻における指定逆潮流電圧値から算出した電圧不平衡率を、力率決定部５４に出力してもよい。この場合、不平衡率算出部５２は、所定の時間の経過後に、その際の外部環境及び時刻を検出して、それと合致する環境及び時刻における指定逆潮流電圧値から算出した電圧不平衡率を、力率決定部５４に出力する。そして、力率決定部５４は、力率ＯＡ、ＯＢ、ＯＣを所定の時間毎に更新しつつ決定する。   The unbalance rate calculation unit 52 detects the current external environment and time, and outputs the voltage unbalance rate calculated from the designated reverse power flow voltage value in the environment and time that matches the current external environment and time to the power factor determination unit 54. May be. In this case, the unbalance rate calculation unit 52 detects the external environment and time at that time after a predetermined time has elapsed, and calculates the voltage unbalance rate calculated from the specified reverse power flow voltage value in the environment and time that matches the external environment and time. , Output to the power factor determination unit 54. Then, the power factor determination unit 54 determines the power factors OA, OB, and OC while updating them every predetermined time.

次に、出力制御部２４による力率の制御フローについて説明する。図８は、本実施形態に係る出力制御部による力率の制御フローを示すフローチャートである。図８に示すように、最初に、出力制御部２４は、力率制御部２８により、決定した力率ＯＡ、ＯＢ、ＯＣの値の情報を力率決定システム４０から取得する（ステップＳ３０）。そして、出力制御部２４は、コンバータ部２６により、発電部２２が発電した直流電力を三相交流電力に変換する（ステップＳ３２）。そして、出力制御部２４は、力率制御部２８により、力率ＯＡ、ＯＢ、ＯＣとなるように、コンバータ部２６によって変換して生成された三相交流電力の無効電力量を制御する（ステップＳ３４）。出力制御部２４は、力率ＯＡ、ＯＢ、ＯＣとなるように変換された三相交流電力を、対応する電圧下での逆潮流電流Ｉｂとして、三相配電分岐線１６に出力する（ステップＳ３６）。これにより、本処理は終了する。   Next, a power factor control flow by the output control unit 24 will be described. FIG. 8 is a flowchart showing a control flow of the power factor by the output control unit according to the present embodiment. As shown in FIG. 8, first, the output control unit 24 acquires information on the determined values of the power factors OA, OB, and OC from the power factor determination system 40 using the power factor control unit 28 (step S30). Then, the output control unit 24 converts the DC power generated by the power generation unit 22 into three-phase AC power using the converter unit 26 (step S32). Then, the output control unit 24 controls the reactive power amount of the three-phase AC power generated by the conversion by the converter unit 26 so that the power factor control unit 28 has power factors OA, OB, and OC (step) S34). The output control unit 24 outputs the three-phase AC power converted to have the power factors OA, OB, and OC to the three-phase distribution branch line 16 as the reverse power flow current Ib under the corresponding voltage (step S36). ). Thereby, this process is complete | finished.

なお、力率決定システム４０が力率ＯＡ、ＯＢ、ＯＣを所定の時間毎に更新しつつ決定する場合、出力制御部２４は、決定された力率ＯＡ、ＯＢ、ＯＣを逐次取得し、その力率ＯＡ、ＯＢ、ＯＣとなるように無効電力量を逐次制御する。これにより、出力制御部２４は、外部環境や時刻等の変動による発電部２２の発電量に応じた適切な力率の制御が可能となる。   When the power factor determination system 40 determines the power factors OA, OB, and OC while updating them every predetermined time, the output control unit 24 sequentially acquires the determined power factors OA, OB, and OC, The reactive power is sequentially controlled so that the power factors are OA, OB, and OC. Thereby, the output control part 24 becomes possible [control of the appropriate power factor according to the electric power generation amount of the electric power generation part 22 by fluctuation | variation of external environment, time, etc.].

以上説明したように、本実施形態に係る力率決定システム４０は、発電所１０からの配電電流Ｉａが供給される三相配電線１４に三相配電分岐線１６を介して接続されて、自然エネルギーによって発電した電力を三相交流の逆潮流電流Ｉｂとして三相配電線１４に供給する発電装置２０が、逆潮流電流Ｉｂを供給する際の力率ＯＡ、ＯＢ、ＯＣを決定する。力率決定システム４０は、インピーダンス取得部４４と、力率指定部４６と、電流値算出部４８と、電圧算出部５０と、不平衡率算出部５２と、力率決定部５４とを有する。インピーダンス取得部４４は、三相配電分岐線１６のインピーダンスを、三相毎に取得する。力率指定部４６は、力率を、三相毎にそれぞれ所定の値である指定力率ＯＡＸ、ＯＢＸ、ＯＣＸに指定する。電流値算出部４８は、予め検出された三相配電分岐線１６を流れる過去逆潮流電流Ｉｃの電流値と、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸとに基づき、指定逆潮流電流値Ｉｄを三相毎に算出する。電圧算出部５０は、算出した指定逆潮流電流値Ｉｄとインピーダンスとに基づき、三相配電線１４における指定逆潮流電圧値を、三相毎に算出する。不平衡率算出部５２は、三相毎の指定逆潮流電圧値Ｉｄに基づき、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸである場合の指定逆潮流電流によって生じる三相配電線１４での電圧不平衡率を算出する。力率決定部５４は、電圧不平衡率が所定の閾値以下である場合に、その指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを、発電装置２０が供給する逆潮流電流Ｉｂの力率ＯＡ、ＯＢ、ＯＣとして決定する。 As described above, the power factor determination system 40 according to the present embodiment is connected to the three-phase distribution line 14 to which the distribution current Ia from the power plant 10 is supplied via the three-phase distribution branch line 16, so that the natural energy The power generation device 20 that supplies the power generated by the above to the three-phase distribution line 14 as the three-phase AC reverse flow current Ib determines the power factors OA, OB, and OC when supplying the reverse flow current Ib. The power factor determination system 40 includes an impedance acquisition unit 44, a power factor designation unit 46, a current value calculation unit 48, a voltage calculation unit 50, an unbalance rate calculation unit 52, and a power factor determination unit 54. The impedance acquisition unit 44 acquires the impedance of the three-phase distribution branch line 16 for each of the three phases. The power factor designating unit 46 designates the power factor as designated power factors OA X , OB X , and OC X that are predetermined values for each of the three phases. The current value calculation unit 48 specifies the designated reverse flow current value Id based on the current value of the past reverse flow current Ic flowing through the three-phase distribution branch line 16 detected in advance and the designated power factors OA X , OB X , OC X. Is calculated for every three phases. The voltage calculation unit 50 calculates the specified reverse flow voltage value in the three-phase distribution line 14 for each of the three phases based on the calculated specified reverse flow current value Id and the impedance. Based on the specified reverse flow voltage value Id for each of the three phases, the unbalance rate calculation unit 52 performs voltage imbalance in the three-phase distribution line 14 caused by the specified reverse flow current when the specified power factor is OA X , OB X , OC X. Calculate the equilibrium rate. When the voltage imbalance rate is equal to or lower than a predetermined threshold, the power factor determination unit 54 uses the specified power factors OA X , OB X , OC X as power factors OA of the reverse flow current Ib supplied by the power generator 20, OB and OC are determined.

発電装置２０は、発電した電力を逆潮流電流Ｉｂとして、三相配電分岐線１６を介して三相配電線１４に供給する。三相配電分岐線１６は、配電電流Ｉａ起因の電圧不平衡を抑制するように各配電線の線間距離や接続相等が設定されているが、逆潮流電流Ｉｂ起因の電圧不平衡を抑制するように設定されていない場合がある。このような場合、配電電流Ｉａとは逆の流れで三相配電分岐線１６を通った逆潮流電流Ｉｂは、三相配電線１４における逆相電圧ＶＮを拡大して、電圧不平衡率を高くしてしまうおそれがある。しかし、本実施形態に係る力率決定システム４０は、予め検出された過去逆潮流電流Ｉｃの電流値と、指定した指定力率ＯＡＸ、ＯＢＸ、ＯＣＸと、三相配電分岐線１６のインピーダンスとに基づき、三相配電線１４での逆潮流電流Ｉｂに起因する電圧不平衡率を算出する。力率決定システム４０は、その電圧不平衡率が低い場合に、指定した指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを、発電装置２０が供給する逆潮流電流Ｉｂの力率ＯＡ、ＯＢ、ＯＣとして決定する。発電装置２０は、電圧不平率が低くなるように決定された力率ＯＡ、ＯＢ、ＯＣで逆潮流電流Ｉｂを出力することで、三相配電線１４における逆相電圧ＶＮの拡大を抑制し、電圧不平衡を抑制する。このように、力率決定システム４０は、不平衡率が低くなるような逆潮流電流Ｉｂの力率ＯＡ、ＯＢ、ＯＣを決定することで、発電装置２０起因の三相配電線１４における電圧不平衡を抑制する。 The power generator 20 supplies the generated power to the three-phase distribution line 14 via the three-phase distribution branch line 16 as a reverse flow current Ib. In the three-phase distribution branch line 16, the line distances and connection phases of the distribution lines are set so as to suppress the voltage imbalance caused by the distribution current Ia, but the voltage imbalance caused by the reverse flow current Ib is suppressed. It may not be set as such. In such a case, the reverse flow current Ib that has passed through the three-phase distribution branch line 16 in a flow opposite to the distribution current Ia expands the reverse-phase voltage V N in the three-phase distribution line 14 and increases the voltage unbalance rate. There is a risk of it. However, the power factor determination system 40 according to the present embodiment includes the current value of the past reverse flow current Ic detected in advance, the designated designated power factors OA X , OB X , OC X, and the three-phase distribution branch line 16. Based on the impedance, the voltage imbalance rate due to the reverse flow current Ib in the three-phase distribution line 14 is calculated. When the voltage imbalance rate is low, the power factor determination system 40 supplies the specified power factors OA X , OB X , OC X specified by the power generator 20 to the power factors OA, OB, OC of the reverse flow current Ib. Determine as. The power generation device 20 outputs the reverse flow current Ib with the power factors OA, OB, and OC determined so that the voltage non-uniformity becomes low, thereby suppressing the expansion of the reverse phase voltage V N in the three-phase distribution line 14, Suppresses voltage imbalance. As described above, the power factor determination system 40 determines the power factors OA, OB, and OC of the reverse flow current Ib so that the unbalance rate becomes low, and thereby the voltage unbalance in the three-phase distribution line 14 caused by the power generator 20. Suppress.

また、発電装置２０は、自然エネルギーによって発電するため、外部環境や時刻に応じた発電量の変動量が大きく、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸとした場合の逆潮流電流Ｉｂの電流値の予測が困難である。しかし、力率決定システム４０は、予め検出した過去逆潮流電流Ｉｃの電流値を用いて、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸとした場合の逆潮流電流Ｉｂの電流値を予測（算出）している。従って、力率決定システム４０は、自然エネルギーによって発電する発電装置２０に対して、電圧不平衡を抑制するための力率を、より正確に決定することができる。 Further, since the power generation device 20 generates power using natural energy, the amount of fluctuation in the amount of power generation according to the external environment and time is large, and the current of the reverse power flow current Ib when the designated power factor OA X , OB X , OC X is used. The value is difficult to predict. However, the power factor determination system 40 predicts (calculates) the current value of the reverse flow current Ib when the designated power factors OA X , OB X , and OC X are used, using the current value of the past reverse flow current Ic detected in advance. )doing. Therefore, the power factor determination system 40 can more accurately determine the power factor for suppressing voltage imbalance with respect to the power generation apparatus 20 that generates power using natural energy.

また、力率決定システム４０は、力率指定部４６と電流値算出部４８と電圧算出部５０と不平衡率算出部５２との処理を、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの値を変化させながら繰り返し実行し、力率決定部５４は、そのうちで電圧不平衡率が最小となった指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを、発電装置２０が供給する逆潮流電流の力率ＯＡ、ＯＢ、ＯＣとして決定する。力率決定システム４０は、複数の算出結果から電圧不平衡率が最小となる指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを、力率ＯＡ、ＯＢ、ＯＣとして決定するため、電圧不平衡をより適切に抑制することができる。 In addition, the power factor determination system 40 performs the processing of the power factor designation unit 46, the current value calculation unit 48, the voltage calculation unit 50, and the unbalance rate calculation unit 52 with the values of the designated power factors OA X , OB X , OC X The power factor determination unit 54 repeatedly performs the specified power factor OA X , OB X , OC X in which the voltage imbalance rate is minimized, and the power of the reverse flow current supplied by the power generator 20. The rates are determined as OA, OB, and OC. The power factor determination system 40 determines the designated power factors OA X , OB X , and OC X that minimize the voltage unbalance rate from a plurality of calculation results as the power factors OA, OB, and OC. It can be suppressed appropriately.

また、力率指定部４６は、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの平均値が、所定の平均力率値となるように、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを指定する。力率指定部４６は、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの平均値を規定することで、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸの個別の値が大きくなり過ぎたり小さくなり過ぎたりすることを抑制する。従って、この力率決定システム４０は、各相における有効電力及び無効電力を適切な範囲内に設定することができる。なお、平均力率値は、０．８５以上１以下である。この場合、この力率決定システム４０は、各相における有効電力及び無効電力を適切な範囲内に設定することができる。また、力率指定部４６は、０．８５以上１以下の範囲で、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸをそれぞれ指定する。この力率指定部４６は、平均値を定めつつ、かつ、指定力率の数値範囲を０．８５から１の間に規定しているため、各相における有効電力及び無効電力を適切な範囲内に設定することができる。 Further, the power factor designation section 46, designated power factor OA X, OB X, the mean value of OC X is to be a predetermined average power factor value, specifies designated power factor OA X, OB X, the OC X . Power factor designation section 46, designated power factor OA X, OB X, by defining the average value of OC X, designated power factor OA X, OB X, too small or individual values OC X is too large It suppresses it. Therefore, this power factor determination system 40 can set the active power and reactive power in each phase within an appropriate range. The average power factor value is 0.85 or more and 1 or less. In this case, the power factor determination system 40 can set the active power and reactive power in each phase within an appropriate range. Further, the power factor designation section 46, a range of 0.85 to 1., specify designated power factor OA X, OB X, OC X respectively. Since the power factor designating unit 46 determines the average value and defines the numerical range of the designated power factor between 0.85 and 1, the active power and reactive power in each phase are within appropriate ranges. Can be set to

なお、本実施形態に係る力率指定部４６は、例えば、平均値が所定の平均力率値となるように、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを指定する代わりに、発電装置２０との接続箇所における三相配電分岐線１６の電圧値（逆潮流電流Ｉｂが流れる際の電圧値）の平均値が、所定の値となるように、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを指定してもよい。同様に、力率指定部４６は、所定の数値範囲内になるように指定力率ＯＡＸ、ＯＢＸ、ＯＣＸをそれぞれ指定する代わりに、発電装置２０との接続箇所における三相配電分岐線１６の電圧値（逆潮流電流Ｉｂが流れる際の電圧値）が、各相全てにおいて、所定の電圧値の範囲内になるように、指定力率ＯＡＸ、ＯＢＸ、ＯＣＸを指定してもよい。 The power factor designating unit 46 according to the present embodiment, for example, instead of designating the designated power factors OA X , OB X , OC X so that the average value becomes a predetermined average power factor value, Designated power factor OA X , OB X , OC X so that the average value of the voltage value of the three-phase distribution branch line 16 at the connection point to the voltage (the voltage value when the reverse flow current Ib flows) becomes a predetermined value. May be specified. Similarly, the power factor designating unit 46 designates the designated power factors OA X , OB X , and OC X so as to be within a predetermined numerical range, respectively, and the three-phase distribution branch line at the connection point with the power generator 20. Designate the specified power factor OA X , OB X , OC X so that the voltage value of 16 (voltage value when the reverse flow current Ib flows) is within the range of the predetermined voltage value in all phases. Also good.

また、本実施形態に係る力率決定システム４０は、三相配電分岐線１６との接続箇所における三相配電線１４の電圧不平衡率、すなわち三相配電線１４と三相配電分岐線１６との連系点を対象箇所として、この対象箇所である連系点における電圧不平衡率が小さくなるように力率を決定している。ただし、電圧不平衡率を小さくする対象箇所は、三相配電線１４と三相配電分岐線１６との連系点に限られず、三相配電線１４や三相配電分岐線１６など、配電システム１中の配電線の任意の箇所に設定することができる。   Further, the power factor determination system 40 according to the present embodiment has a voltage unbalance rate of the three-phase distribution line 14 at the connection point with the three-phase distribution branch line 16, that is, the connection between the three-phase distribution line 14 and the three-phase distribution branch line 16. Taking the system point as a target location, the power factor is determined so that the voltage unbalance rate at the interconnection point that is the target location is small. However, the target location for reducing the voltage imbalance rate is not limited to the connection point between the three-phase distribution line 14 and the three-phase distribution branch line 16, and the three-phase distribution line 14, the three-phase distribution branch line 16, and the like in the distribution system 1. Can be set at any location on the distribution line.

以上、本発明の実施形態について説明したが、これら実施形態の内容によりこの発明が限定されるものではない。また、前述した構成要素には、当業者が容易に想定できるもの、実質的に同一のもの、いわゆる均等の範囲のものが含まれる。さらに、前述した構成要素は適宜組み合わせることが可能である。さらに、前述した実施形態の要旨を逸脱しない範囲で構成要素の種々の省略、置換又は変更を行うことができる。   As mentioned above, although embodiment of this invention was described, this invention is not limited by the content of these embodiment. In addition, the above-described constituent elements include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the above-described components can be appropriately combined. Furthermore, various omissions, substitutions, or changes of the components can be made without departing from the spirit of the above-described embodiment.

１ 配電システム
１０ 発電所
１１ 送電線
１２ 配電用変電所
１４ 三相配電線
１６ 三相配電分岐線
２０ 発電装置
２２ 発電部
２４ 出力制御部
２６ コンバータ部
２８ 力率制御部
３０ 検出部
４０ 力率決定システム
４２ 電流値取得部
４４ インピーダンス取得部
４６ 力率指定部
４８ 電流値算出部
５０ 電圧算出部
５２ 不平衡率算出部
５４ 力率決定部 DESCRIPTION OF SYMBOLS 1 Power distribution system 10 Power station 11 Transmission line 12 Distribution substation 14 Three-phase distribution line 16 Three-phase distribution branch line 20 Power generator 22 Power generation part 24 Output control part 26 Converter part 28 Power factor control part 30 Detection part 40 Power factor determination system 42 Current value acquisition unit 44 Impedance acquisition unit 46 Power factor specification unit 48 Current value calculation unit 50 Voltage calculation unit 52 Unbalance rate calculation unit 54 Power factor determination unit

Claims (7)

発電所からの三相交流電流が供給される三相配電線に三相配電分岐線を介して接続されて、自然エネルギーによって発電した電力を三相交流の逆潮流電流として前記三相配電線に供給する発電装置が、前記逆潮流電流を供給する際の力率を決定する力率決定方法であって、
前記三相配電分岐線のインピーダンスを、三相毎に取得するインピーダンス取得ステップと、
前記力率を、三相毎にそれぞれ所定の値である指定力率に指定する力率指定ステップと、
予め検出された前記三相配電分岐線を流れる逆潮流電流の電流値と、前記指定力率とに基づき、前記指定力率である場合に前記三相配電分岐線に流れる逆潮流電流の電流値を、三相毎に算出する電流値算出ステップと、
算出した前記電流値と前記インピーダンスとに基づき、前記三相配電分岐線における電圧値を、三相毎に算出する電圧算出ステップと、
前記三相配電分岐線における三相毎の電圧値に基づき、前記指定力率である場合の逆潮流電流によって生じる前記三相配電線での電圧不平衡率を算出する不平衡率算出ステップと、
前記電圧不平衡率が所定の閾値以下である場合に、前記指定力率を、前記発電装置が供給する逆潮流電流の力率として決定する力率決定ステップと、
を有する力率決定方法。 Connected via a three-phase distribution branch line to a three-phase distribution line to which a three-phase alternating current from a power plant is supplied, and supplies the power generated by natural energy to the three-phase distribution line as a reverse flow current of the three-phase alternating current A power factor determination method for determining a power factor when the power generation device supplies the reverse flow current,
Impedance acquisition step of acquiring the impedance of the three-phase distribution branch line for each of the three phases;
A power factor designating step of designating the power factor to a designated power factor that is a predetermined value for each of the three phases;
Based on the detected current value of the reverse flow current flowing through the three-phase distribution branch line and the specified power factor, the current value of the reverse flow current flowing through the three-phase distribution branch line when the specified power factor is reached Current value calculation step for calculating every three phases;
Based on the calculated current value and the impedance, a voltage calculation step for calculating a voltage value in the three-phase distribution branch line for each of the three phases;
Based on the voltage value for each of the three phases in the three-phase distribution branch line, an unbalance rate calculation step for calculating a voltage unbalance rate in the three-phase distribution line caused by a reverse power flow current at the specified power factor;
A power factor determination step for determining the designated power factor as a power factor of a reverse flow current supplied by the power generator when the voltage imbalance rate is equal to or less than a predetermined threshold;
A power factor determination method. 前記力率指定ステップと前記電流値算出ステップと前記不平衡率算出ステップとを、前記指定力率の値を変化させながら繰り返し実行し、前記力率決定ステップは、そのうちで前記電圧不平衡率が最小となった前記指定力率を、前記発電装置が供給する逆潮流電流の力率として決定する、請求項１に記載の力率決定方法。   The power factor specifying step, the current value calculating step, and the unbalance rate calculating step are repeatedly executed while changing the value of the specified power factor, and the power factor determining step includes the voltage unbalance rate being The power factor determination method according to claim 1, wherein the specified power factor that is minimized is determined as a power factor of a reverse flow current supplied by the power generator. 前記力率指定ステップは、三相の指定力率の平均値が、所定の平均力率値となるように、前記指定力率を指定する、請求項１又は請求項２に記載の力率決定方法。   The power factor determination according to claim 1 or 2, wherein the power factor designation step designates the designated power factor so that an average value of three-phase designated power factors becomes a predetermined average power factor value. Method. 前記平均力率値は、０．８５以上１以下である、請求項３に記載の力率決定方法。   The power factor determination method according to claim 3, wherein the average power factor value is 0.85 or more and 1 or less. 前記力率指定ステップは、０．８５以上１以下の範囲で、三相の指定力率をそれぞれ指定する、請求項４に記載の力率決定方法。   5. The power factor determination method according to claim 4, wherein the power factor designation step designates a three-phase designated power factor within a range of 0.85 to 1. 5. 発電所からの三相交流電流が供給される三相配電線に三相配電分岐線を介して接続されて、自然エネルギーによって発電した電力を三相交流の逆潮流電流として前記三相配電線に供給する発電装置が、前記逆潮流電流を供給する際の力率を決定する力率決定システムであって、
前記三相配電分岐線のインピーダンスを、三相毎に取得するインピーダンス取得部と、
前記力率を、三相毎にそれぞれ所定の値である指定力率に指定する力率指定部と、
予め検出された前記三相配電分岐線を流れる逆潮流電流の電流値と、前記指定力率とに基づき、前記指定力率である場合に前記三相配電分岐線に流れる逆潮流電流の電流値を、三相毎に算出する電流値算出部と、
算出した前記電流値と前記インピーダンスとに基づき、前記三相配電分岐線における電圧値を、三相毎に算出する電圧算出部と、
前記三相配電分岐線における三相毎の電圧値に基づき、前記指定力率である場合の逆潮流電流によって生じる前記三相配電線での電圧不平衡率を算出する不平衡率算出部と、
前記電圧不平衡率が所定の閾値以下である場合に、前記指定力率を、前記発電装置が供給する逆潮流電流の力率として決定する力率決定部と、
を有する力率決定システム。 Connected via a three-phase distribution branch line to a three-phase distribution line to which a three-phase alternating current from a power plant is supplied, and supplies the power generated by natural energy to the three-phase distribution line as a reverse flow current of the three-phase alternating current A power factor determination system for determining a power factor when the power generation device supplies the reverse flow current,
An impedance acquisition unit for acquiring the impedance of the three-phase distribution branch line for each of the three phases;
A power factor designating unit that designates the power factor as a designated power factor that is a predetermined value for each of the three phases;
Based on the detected current value of the reverse flow current flowing through the three-phase distribution branch line and the specified power factor, the current value of the reverse flow current flowing through the three-phase distribution branch line when the specified power factor is reached Current value calculation unit for calculating for each three phases,
Based on the calculated current value and the impedance, a voltage calculation unit that calculates a voltage value in the three-phase distribution branch line for each of the three phases;
Based on the voltage value for each of the three phases in the three-phase distribution branch line, an unbalance rate calculation unit that calculates a voltage unbalance rate in the three-phase distribution line caused by a reverse power flow current at the specified power factor,
A power factor determination unit that determines the specified power factor as a power factor of a reverse flow current supplied by the power generator when the voltage imbalance rate is equal to or less than a predetermined threshold;
Having power factor determination system. 自然エネルギーによって発電する発電部と、
発電所からの三相交流電流が供給される三相配電線に三相配電分岐線を介して接続されて、前記発電部が発電した電力を三相交流の逆潮流電流として前記三相配電線に供給する出力制御部と、
前記出力制御部が前記逆潮流電流を供給する際の力率を決定する決定する力率決定システムと、を有し、
前記力率決定システムは、
前記三相配電分岐線のインピーダンスを、三相毎に取得するインピーダンス取得部と、
前記力率を、三相毎にそれぞれ所定の値である指定力率に指定する力率指定部と、
予め検出された前記三相配電分岐線を流れる逆潮流電流の電流値と、前記指定力率とに基づき、前記指定力率である場合に前記三相配電分岐線に流れる逆潮流電流の電流値を、三相毎に算出する電流値算出部と、
算出した前記電流値と前記インピーダンスとに基づき、前記三相配電分岐線における電圧値を、三相毎に算出する電圧算出部と、
前記三相配電分岐線における三相毎の電圧値に基づき、前記指定力率である場合の逆潮流電流によって生じる前記三相配電線での電圧不平衡率を算出する不平衡率算出部と、
前記電圧不平衡率が所定の閾値以下である場合に、前記指定力率を、前記発電装置が供給する逆潮流電流の力率として決定する力率決定部と、を有し、
前記出力制御部は、前記力率決定部が決定した力率で、前記逆潮流電流を供給する、配電システム。 A power generation unit that generates power using natural energy;
Connected via a three-phase distribution branch line to a three-phase distribution line to which a three-phase alternating current from a power station is supplied, and supplies the power generated by the power generation unit to the three-phase distribution line as a reverse flow current of the three-phase alternating current An output control unit,
A power factor determination system that determines a power factor when the output control unit supplies the reverse flow current;
The power factor determination system includes:
An impedance acquisition unit for acquiring the impedance of the three-phase distribution branch line for each of the three phases;
A power factor designating unit that designates the power factor as a designated power factor that is a predetermined value for each of the three phases;
Based on the detected current value of the reverse flow current flowing through the three-phase distribution branch line and the specified power factor, the current value of the reverse flow current flowing through the three-phase distribution branch line when the specified power factor is reached Current value calculation unit for calculating for each three phases,
Based on the calculated current value and the impedance, a voltage calculation unit that calculates a voltage value in the three-phase distribution branch line for each of the three phases;
Based on the voltage value for each of the three phases in the three-phase distribution branch line, an unbalance rate calculation unit that calculates a voltage unbalance rate in the three-phase distribution line caused by a reverse power flow current at the specified power factor,
A power factor determination unit that determines the specified power factor as a power factor of a reverse flow current supplied by the power generator when the voltage imbalance rate is equal to or less than a predetermined threshold;
The power distribution system, wherein the output control unit supplies the reverse flow current at a power factor determined by the power factor determination unit.
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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08294234A (en) * 1995-04-20 1996-11-05 Fuji Electric Co Ltd Power factor control device
JPH1127864A (en) * 1997-07-01 1999-01-29 Fuji Electric Co Ltd Automatic power factor adjustment device for grid connection
JP2003092828A (en) * 2001-09-18 2003-03-28 Kansai Electric Power Co Inc:The Distribution equipment model and three-phase unbalanced power flow calculation method
JP2004088824A (en) * 2002-08-23 2004-03-18 Hitachi Ltd Power equipment coordination controller
JP2007058676A (en) * 2005-08-25 2007-03-08 Tokyo Institute Of Technology AC voltage controller using phase advance current
US20110255307A1 (en) * 2010-04-16 2011-10-20 Sungkyunkwan University Foundation For Corporate Collaboration Apparatus and method for controling power quality of power generation system
JP2013509157A (en) * 2009-10-25 2013-03-07 アーベーベー・リサーチ・リミテッド Method and apparatus for improving the operation of an auxiliary power system in a thermal power plant
JP2014183710A (en) * 2013-03-21 2014-09-29 Chugoku Electric Power Co Inc:The Connection phase determination method and connection phase determination device
JP2014533084A (en) * 2011-10-27 2014-12-08 サンパワー コーポレイション Master / slave architecture for controlling the operation of photovoltaic power plants

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08294234A (en) * 1995-04-20 1996-11-05 Fuji Electric Co Ltd Power factor control device
JPH1127864A (en) * 1997-07-01 1999-01-29 Fuji Electric Co Ltd Automatic power factor adjustment device for grid connection
JP2003092828A (en) * 2001-09-18 2003-03-28 Kansai Electric Power Co Inc:The Distribution equipment model and three-phase unbalanced power flow calculation method
JP2004088824A (en) * 2002-08-23 2004-03-18 Hitachi Ltd Power equipment coordination controller
JP2007058676A (en) * 2005-08-25 2007-03-08 Tokyo Institute Of Technology AC voltage controller using phase advance current
JP2013509157A (en) * 2009-10-25 2013-03-07 アーベーベー・リサーチ・リミテッド Method and apparatus for improving the operation of an auxiliary power system in a thermal power plant
US20110255307A1 (en) * 2010-04-16 2011-10-20 Sungkyunkwan University Foundation For Corporate Collaboration Apparatus and method for controling power quality of power generation system
JP2014533084A (en) * 2011-10-27 2014-12-08 サンパワー コーポレイション Master / slave architecture for controlling the operation of photovoltaic power plants
JP2014183710A (en) * 2013-03-21 2014-09-29 Chugoku Electric Power Co Inc:The Connection phase determination method and connection phase determination device

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