JP2001051734A - Reactive power compensation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an reactive power compensation system stabilizing the instant voltage fluctuation which continuously occurs even in a distribution line where plural loads in which instantaneous voltage fluctuation occur are connected. SOLUTION: This reactive power compensation system has a circuit 19 extracting an instant (several ten milliseconds) voltage fluctuation component from plural frequency bands contained in the detection value of system voltage, a circuit 15 multiplying a gain K1, a circuit 16 extracting an intermediate frequency voltage fluctuation component lower than instant voltage fluctuation, a circuit 17 multiplying a gain K2 (<K1) and a circuit 18 adding both extracted components. Reactive current commands corresponding to the extracted signals are issued and a reactive power compensation device 3 is operated. Voltage after instant voltage fluctuation ΔV is compensated with the high gain K1 is dropped in a short time, it is kept to a voltage level which is slightly less than the dead zone lower limit of a voltage adjuster 2 by the gain K2 and compensation sharing to the voltage adjuster 2, which is decided by the product of the operation time limit of the voltage adjuster 2 and the number of tap switching times, which compensates ΔV, is completed in almost minimum time.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、電力系統に設置さ
れ系統の電圧変動を電圧調整器と分担して補償する無効
電力補償システムに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactive power compensation system installed in a power system and compensating for voltage fluctuations in the system by sharing the voltage fluctuation with a voltage regulator.

【０００２】[0002]

【従来の技術】最近の配電系統では、昼夜の負荷変化に
よる１日の電圧差が拡大する常時電圧変動に加えて、大
容量電動機負荷等による瞬時電圧変動が頻発している。
このような瞬時電圧変動は地域的な偏りが著しく、例え
ば砕石機、スキーリフト、クレーン、アーク炉などの負
荷が多い配電線では、それらの始動時や過負荷時などに
瞬時電圧低下が多発する。一方、ＯＡ機器等の電子装置
はこの瞬時電圧変動による誤動作の恐れが有り、特に配
電線定格のあるレベル以下になると機器がダウンして、
その影響が広範に及ぶこともある。このため、変動周期
の長い常時の電圧変動から数十ミリ秒程度の瞬時の電圧
変動までを対象とした広い周波数領域にわたる電圧品質
の維持が必要となっている。2. Description of the Related Art In recent power distribution systems, instantaneous voltage fluctuations due to a large-capacity motor load and the like frequently occur in addition to constant voltage fluctuations in which the voltage difference between the day and night increases due to load changes during the day and night.
Such instantaneous voltage fluctuations are remarkably localized, and, for example, in distribution lines with a large load such as lithotripters, ski lifts, cranes, and arc furnaces, instantaneous voltage drops frequently occur when starting or overloading them. . On the other hand, electronic devices such as OA equipment may malfunction due to this instantaneous voltage fluctuation, and particularly when the distribution line rating falls below a certain level, the equipment goes down,
The effects can be far-reaching. For this reason, it is necessary to maintain the voltage quality over a wide frequency range from a constant voltage fluctuation having a long fluctuation period to an instantaneous voltage fluctuation of about several tens of milliseconds.

【０００３】図９に、配電線の電圧変動の状況を示す。
（ａ）は１日負荷による２４時間周期の常時電圧変動
と、これに重畳するヒゲ状の短時間の電圧変動を示して
いる。短時間の電圧変動は昼間の特定の時間帯に集中的
に発生することが多い。（ｂ）は、短時間の電圧変動が
発生している時間帯の一部を示している。特殊負荷、例
えば大容量誘導電動機では始動時に定格の数倍の起動電
流によって電圧変化が発生する。これら短時間の電圧変
動は、数十ミリ〜数秒の瞬時成分から数分程度に及ぶ範
囲の周波数帯域を有している。FIG. 9 shows a state of voltage fluctuation of a distribution line.
(A) shows a 24-hour constant voltage fluctuation due to a daily load, and a short-term mustache-like voltage fluctuation superimposed thereon. Short-term voltage fluctuations often occur intensively at a specific time in the daytime. (B) shows a part of a time zone in which a short-time voltage fluctuation occurs. In a special load, for example, a large-capacity induction motor, a voltage change occurs at the time of starting due to a starting current that is several times the rating. These short-term voltage fluctuations have a frequency band ranging from an instantaneous component of several tens of millimeters to several seconds to several minutes.

【０００４】配電系統における主な電圧変動の制御装置
として、電圧調整器と無効電力補償装置の２種類があ
る。電圧調整器は配電線上に設置し、２次側の電圧をタ
ップの切り換えにより調整する。具体的には、設置点よ
り２次側の電圧と基準電圧の差が、あらかじめ設定され
た不感帯幅を越え、かつその時間が所定の動作時限を越
えた時に、電圧を不感帯内に戻す方向にタップを切り換
える。このとき、頻繁なタップ切り換えによる機械接点
の磨耗を防ぐため、動作時限を通常３０秒〜２分程度に
設定している。There are two main types of voltage fluctuation control devices in a distribution system: a voltage regulator and a reactive power compensator. The voltage regulator is installed on the distribution line, and adjusts the voltage on the secondary side by switching taps. Specifically, when the difference between the voltage on the secondary side from the installation point and the reference voltage exceeds a preset dead zone width and the time exceeds a predetermined operation time limit, the voltage is returned to the dead zone. Switch taps. At this time, in order to prevent wear of the mechanical contacts due to frequent tap switching, the operation time limit is usually set to about 30 seconds to 2 minutes.

【０００５】無効電力補償装置は、例えば自励式の無効
電力補償システムの場合、インバータを用いて高速かつ
連続的に進みから遅れまでの無効電力を発生して線路電
圧を補償する。無効電力補償装置では、例えば数十ミリ
秒のオーダで高速に電圧変動を補償することが可能であ
る。高速制御可能な無効電力補償装置を用いれば、理論
的には常時変動から瞬時変動までの電圧補償が可能であ
る。しかし、配電系統の負荷容量に匹敵する装置容量が
必要となるので、設置スペース、重量、コスト等の制約
から実現は難しい。For example, in the case of a self-excited reactive power compensating system, a reactive power compensating device compensates for line voltage by generating reactive power from a lead to a lag continuously at high speed using an inverter. In the reactive power compensator, for example, voltage fluctuation can be compensated at high speed on the order of several tens of milliseconds. If a reactive power compensator capable of high-speed control is used, theoretically, voltage compensation from constant fluctuation to instantaneous fluctuation is possible. However, since a device capacity equivalent to the load capacity of the power distribution system is required, it is difficult to realize the apparatus due to restrictions on installation space, weight, cost, and the like.

【０００６】そこで、電圧調整器と無効電力補償装置を
同一配電線に併設して、両者の役割分担を図ることが行
われている。即ち、変動時間の長い常時電圧変動は電圧
調整器が補償し、変動時間の短い瞬時電圧変動を無効電
力補償装置が補償するように分担し、広い周波数領域に
わたる電圧変動抑制を実現している。[0006] Therefore, it has been practiced to install a voltage regulator and a reactive power compensator in the same distribution line so as to share the roles of both. That is, the voltage regulator compensates for the constant voltage fluctuation with a long fluctuation time, and the reactive power compensator compensates for the instantaneous voltage fluctuation with a short fluctuation time, thereby realizing voltage fluctuation suppression over a wide frequency range.

【０００７】このような電圧調整器との役割分担を行う
無効電力補償装置として、例えば、特開平5−27856号公
報に記載されたものが知られている。この無効電力補償
装置の制御回路では、配電線電圧Ｖを低域通過フィルタ
に通し、その入出力の差より配電線電圧中の変化率の速
い電圧変動成分△ＶＦを抽出し（結果として、高域通過
フィルタとして作用）、この△ＶＦを零にするように無
効電力補償量を制御している。一方、電圧調整器は制御
速度が遅いため、無効電力補償システムが補償しない比
較的変化率の遅い電圧変動分を調整する。その結果、瞬
時電圧変動を無効電力補償システム、常時電圧変動を電
圧調整器という補償分担が行われている。[0007] As a reactive power compensator for performing the role sharing with such a voltage regulator, for example, the one described in Japanese Patent Application Laid-Open No. 5-27856 is known. In the control circuit of this reactive power compensator, the distribution line voltage V is passed through a low-pass filter, and a voltage fluctuation component ΔVF having a fast rate of change in the distribution line voltage is extracted from the input / output difference (as a result, (Acts as a band-pass filter), and controls the amount of reactive power compensation to make this △ VF zero. On the other hand, since the voltage regulator has a slow control speed, the voltage regulator adjusts a relatively slow voltage change which is not compensated by the reactive power compensation system. As a result, compensation is shared such as reactive power compensation system for instantaneous voltage fluctuation and voltage regulator for constant voltage fluctuation.

【０００８】[0008]

【発明が解決しようとする課題】従来の無効電力補償シ
ステムは電圧調整器との協調動作に欠ける面があり、無
効電力補償装置が配電線の瞬時変動電圧の補償後に電圧
調整器へ補償分担する過程に長時間を要し、結果的に、
この間における無効電力補償システムの瞬時変動の補償
能力を低下させていた。The conventional reactive power compensation system lacks cooperative operation with the voltage regulator, and the reactive power compensator allocates compensation to the voltage regulator after compensating for the instantaneous fluctuation voltage of the distribution line. The process takes a long time, and as a result,
During this time, the ability of the reactive power compensation system to compensate for instantaneous fluctuations has been reduced.

【０００９】図１０に、従来の無効電力補償装置の電圧
変動抽出特性を示す。図示の横軸は時間、縦軸は電圧で
ある。Ｔ１は上記引用例におけるフィルタの時定数で、
低域フィルタ（１／（１＋Ｔ１））、または高域フィル
タ（１−１／（１＋Ｔ１）＝Ｔ１／１＋Ｔ１）での時定
数Ｔ１である。FIG. 10 shows a voltage fluctuation extraction characteristic of a conventional reactive power compensator. The horizontal axis in the drawing is time, and the vertical axis is voltage. T1 is the time constant of the filter in the above cited example,
This is the time constant T1 of the low-pass filter (1 / (1 + T1)) or the high-pass filter (1-1 / (1 + T1) = T1 / 1 + T1).

【００１０】Ｔ１が大の場合、Ｔ１が小の場合の２通り
の特性を示している。いま、ｔ０で瞬時電圧低下が発生
すると、無効電力補償装置は直ちにこの瞬時変動を補償
する。その後、時間の経過とともに電圧変動が低周波側
へ移行するので、変化率の速い電圧変動成分△ＶＦの抽
出量が時定数Ｔ１の逆数（カットオフ周波数＝１／Ｔ）
に応じて下がる。このため、無効電力補償装置の補償量
が低下し、電圧も低下する。この電圧が電圧調整器の不
感帯下限レベルを超えて、動作時限の時間を過ぎると、
電圧調整器のタップが動作し、下がった電圧を分担す
る。このようにして、瞬時領域で無効電力補償装置が担
った電圧補償分が、電圧調整器へと分担されていく。Two characteristics are shown when T1 is large and when T1 is small. Now, when an instantaneous voltage drop occurs at t0, the reactive power compensator immediately compensates for this instantaneous fluctuation. After that, the voltage fluctuation shifts to the low frequency side with the passage of time, so the amount of extraction of the voltage fluctuation component ΔVF having a fast change rate is the reciprocal of the time constant T1 (cutoff frequency = 1 / T).
Go down according to. For this reason, the amount of compensation of the reactive power compensator decreases, and the voltage also decreases. When this voltage exceeds the dead band lower limit level of the voltage regulator and the time of the operation time expires,
The tap of the voltage regulator operates and shares the dropped voltage. In this way, the voltage compensation performed by the reactive power compensator in the instantaneous region is shared by the voltage regulator.

【００１１】ところで、時定数Ｔ１が小さいほど電圧低
下が速いので、配電電圧が不感帯下限レベルを超えてか
ら動作時限に至る前に許容限界（定格未満のあるレベ
ル）以下となる恐れがある。このため、従来は時定数Ｔ
１を大きくして、電圧調整器の動作時限に至る前に配電
電圧が許容限界まで低下しないようにしている。つま
り、瞬時補償後の配電電圧が緩やかになるように、無効
電力補償装置を動作させている。しかし、電圧調整器と
の過渡的な補償分担過程に長い時間を要するため、連続
的に瞬時電圧変動が発生するような配電線では、補償中
に発生した次の瞬時電圧変動を補償しきれず、配電線上
の他の負荷に障害が引き起こされる問題があった。Since the voltage drop is faster as the time constant T1 is smaller, the distribution voltage may fall below the allowable limit (a level below the rating) before reaching the operation time limit after exceeding the dead band lower limit level. For this reason, conventionally, the time constant T
The value 1 is increased so that the distribution voltage does not drop to an allowable limit before the operation time of the voltage regulator is reached. That is, the reactive power compensator is operated so that the distribution voltage after the instantaneous compensation becomes gentle. However, since it takes a long time for the transient compensation sharing process with the voltage regulator, in a distribution line where instantaneous voltage fluctuations occur continuously, the next instantaneous voltage fluctuations generated during compensation cannot be compensated. There was a problem that other loads on the distribution line could be damaged.

【００１２】本発明の目的は、上記従来技術の問題点を
克服し、配電線に連続的に瞬時電圧変動が発生するよう
な場合にも、安定な配電電圧を補償しながら電圧調整器
との過渡的な補償分担過程の期間を短縮して、次々と起
こる瞬時電圧変動に対して十分な補償効果が得られるよ
うな無効電力補償システムを提供することにある。An object of the present invention is to overcome the above-mentioned problems of the prior art, and to compensate for a stable distribution voltage even when instantaneous voltage fluctuations occur continuously in a distribution line. It is an object of the present invention to provide a reactive power compensation system in which the period of the transient compensation sharing process is shortened and a sufficient compensation effect is obtained for successive instantaneous voltage fluctuations.

【００１３】[0013]

【課題を解決するための手段】上記課題を解決する本発
明は、変動周期の長い常時電圧変動を補償する電圧調整
装置及び変動周期の短い瞬時電圧変動を補償する無効電
力補償装置を接続し、この両装置による電圧補償の分担
が行われる電力系統に対し、系統電圧に応じた無効電力
補償量を求めて前記無効電力補償装置を制御する制御装
置を備えた無効電力補償システムにおいて、前記制御装
置は、検出した系統電圧から前記瞬時電圧変動の瞬時成
分と、前記瞬時電圧変動と前記常時電圧変動の中間周波
領域にある中間成分を抽出する電圧変動成分抽出手段を
設け、抽出した両成分に基づいて前記無効電力補償量を
算出することを特徴とする。なお、上記の無効電力補償
量は無効電流補償量と置き換えてもよい。According to the present invention, a voltage regulator for compensating for a constant voltage fluctuation having a long fluctuation period and a reactive power compensating device for compensating for an instantaneous voltage fluctuation having a short fluctuation period are connected. In a reactive power compensation system including a control device for controlling a reactive power compensating device by obtaining a reactive power compensation amount according to a system voltage for a power system in which voltage sharing is performed by the two devices, the control device Is provided with voltage fluctuation component extraction means for extracting an instantaneous component of the instantaneous voltage fluctuation from the detected system voltage, and an intermediate component in an intermediate frequency region of the instantaneous voltage fluctuation and the constant voltage fluctuation, based on both extracted components. Calculating the reactive power compensation amount. Note that the above-described reactive power compensation amount may be replaced with a reactive current compensation amount.

【００１４】または、前記制御装置は、検出した系統電
圧から前記瞬時電圧変動の瞬時成分と、前記瞬時電圧変
動より変動周期の長い中間周波成分を抽出する電圧変動
成分抽出手段を設け、前記瞬時成分を補償後の前記中間
周波成分の電圧補償分担が前記電圧調整装置の補償動作
（速度）と協調するように、前記電圧変動成分抽出手段
の制御定数を設定してなることを特徴とする。Alternatively, the control device includes voltage fluctuation component extraction means for extracting an instantaneous component of the instantaneous voltage fluctuation and an intermediate frequency component having a fluctuation cycle longer than the instantaneous voltage fluctuation from the detected system voltage. The control constant of the voltage fluctuation component extracting means is set so that the voltage compensation sharing of the intermediate frequency component after the compensation cooperates with the compensation operation (speed) of the voltage regulator.

【００１５】前記電圧変動成分抽出手段は、前記瞬時成
分以上を通過させる第１のフィルタと、前記中間成分を
通過させる第２のフィルタと、前記第１のフィルタの出
力に第１のゲインを乗じ、前記第２のフィルタの出力に
前記第１のゲインより小さい第２のゲインを乗じ、この
両乗算の結果を加算する演算回路を設けてなる。The voltage fluctuation component extracting means multiplies an output of the first filter by a first gain, a second filter by which the intermediate component is passed, a second filter by which the intermediate component is passed, and a first gain. , An arithmetic circuit for multiplying the output of the second filter by a second gain smaller than the first gain and adding the results of the multiplication.

【００１６】また、前記第１のフィルタのカットオフ周
波数（または、時定数の逆数）は系統電圧が許容限度以
下に低下しない範囲で大きく、かつ、前記第２のゲイン
は系統電圧が前記電圧調整器の不感帯下限を僅かに下回
る値に保持されるように、それぞれ設定してなる。これ
により、前記電圧調整装置の電圧補償動作の速度と協調
して、ほぼ最小の時間で、無効電力制御装置から電圧調
整器への電圧補償分担を完了できる。Further, the cut-off frequency (or the reciprocal of the time constant) of the first filter is large within a range where the system voltage does not drop below an allowable limit, and the second gain is set so that the system voltage is adjusted by the voltage adjustment. Each is set so as to be maintained at a value slightly below the lower limit of the dead zone of the vessel. Thereby, in cooperation with the speed of the voltage compensation operation of the voltage regulation device, the voltage compensation sharing from the reactive power control device to the voltage regulator can be completed in almost the minimum time.

【００１７】また、前記制御装置は、前記電圧変動成分
抽出手段の出力を入力とし、所定不感帯幅を持つ不感帯
回路を設けてなる。この不感帯幅を、前記電圧調整装置
の１回のタップ補償電圧を僅かに上回る値に設定する
と、無効電力補償装置が前記電圧調整装置のタップ切り
換えに応動して瞬時的に電圧補償する不要動作を回避で
き、無効電力補償装置の補償量を確保できる。Further, the control device is provided with a dead zone circuit having an input of an output of the voltage fluctuation component extracting means and having a predetermined dead zone width. If this dead band width is set to a value slightly higher than one tap compensation voltage of the voltage regulator, the unnecessary operation of the reactive power compensator instantaneously compensating the voltage in response to the tap change of the voltage regulator is eliminated. It is possible to avoid this and secure the amount of compensation of the reactive power compensator.

【００１８】また、前記制御装置は、系統電圧の検出値
と前記無効電力補償装置の出力電流検出値とを用いて系
統に生じた電圧変動を推定し、前記電圧変動成分抽出手
段の制御定数を設定変更する手段を設けたことを特徴と
する。これにより、系統電圧の変動に応じて、上記のフ
ィルタの時定数や抽出ゲインが最適化でき、より効率的
な電圧補償分担が可能になる。Further, the control device estimates a voltage fluctuation occurring in the system using a detected value of a system voltage and a detected value of an output current of the reactive power compensating device, and determines a control constant of the voltage fluctuation component extracting means. A means for changing the setting is provided. As a result, the time constant and the extraction gain of the above-described filter can be optimized according to the fluctuation of the system voltage, and more efficient voltage compensation can be shared.

【００１９】本発明によれば、瞬時電圧変動の瞬時成分
は高いゲインで抽出して補償することができる。その
後、瞬時電圧変動が継続して瞬時と常時の間の中間周波
変動の周波数領域に移ると、中間周波成分が抽出される
ようになる。この中間周波変動は瞬時変動よりも低い所
定ゲインで抽出し、無効電力補償量を適当な量にして、
系統電圧を電圧調整器の不感帯幅（下限）を少し越えた
値に保持することができる。この結果、瞬時の電圧補償
後の電圧調整器への過渡的な補償分担を、短時間で、か
つその過程で生じる電圧変化を必要最小に抑えて完了で
きる。従って、瞬時電圧変動が連続的に発生するような
配電線においても、無効電力補償システムは補償量を十
分確保した状態で次の瞬時変動を補償することができ
る。According to the present invention, the instantaneous component of the instantaneous voltage fluctuation can be extracted and compensated with a high gain. After that, when the instantaneous voltage fluctuation continues to move to the frequency region of the intermediate frequency fluctuation between the instant and the normal, the intermediate frequency component is extracted. This intermediate frequency fluctuation is extracted with a predetermined gain lower than the instantaneous fluctuation, and the reactive power compensation amount is set to an appropriate amount.
The system voltage can be maintained at a value slightly exceeding the dead band width (lower limit) of the voltage regulator. As a result, the transient compensation sharing to the voltage regulator after the instantaneous voltage compensation can be completed in a short time and with the voltage change occurring in the process being minimized. Therefore, even in a distribution line in which instantaneous voltage fluctuations occur continuously, the reactive power compensation system can compensate for the next instantaneous fluctuations with a sufficient amount of compensation secured.

【００２０】なお、瞬時電圧変動とは少なくとも電圧調
整器の動作時限よりも短い時間の電圧変動で、数十ミリ
秒から数秒の時間で起こる電圧変動を表す。また常時電
圧変動とは、電圧調整器の電圧調整動作が十分収束する
程度の時間に対応する電圧変動で、数分以上の電圧変動
を表し、中間周波変動とは瞬時電圧変動と常時電圧変動
の中間の周波領域の電圧変動を表す。It should be noted that the instantaneous voltage fluctuation is a voltage fluctuation at least for a time shorter than the operation time limit of the voltage regulator, and represents a voltage fluctuation occurring in a time of several tens of milliseconds to several seconds. Also, the constant voltage fluctuation is a voltage fluctuation corresponding to a time period in which the voltage adjustment operation of the voltage regulator converges sufficiently, and represents a voltage fluctuation of several minutes or more.The intermediate frequency fluctuation is a voltage fluctuation of the instantaneous voltage fluctuation and the constant voltage fluctuation. It represents the voltage fluctuation in the middle frequency range.

【００２１】さらに、本発明における無効電力補償装置
とは、進みから遅れまでの無効電力を連続的に出力し
て、電圧調整器よりも高速に（例えば、数百ミリ秒以
下）電圧変動を補償する装置を指し、機械的接点を用い
ないサイリスタ、ＩＧＢＴ等のパワーデバイスにより構
成される。また、電圧調整器とは、タップの切替により
段階的に電圧する装置を指し、通常は数秒〜数分の動作
時限を持つタップ切替装置とタップ付きトランスを使用
する。Further, the reactive power compensator according to the present invention continuously outputs the reactive power from the lead to the delay, and compensates for the voltage fluctuation faster (for example, several hundred milliseconds or less) than the voltage regulator. And a power device such as a thyristor or IGBT that does not use mechanical contacts. The voltage regulator refers to a device that gradually increases the voltage by switching taps, and usually uses a tap switching device having an operation time limit of several seconds to several minutes and a transformer with a tap.

【００２２】[0022]

【発明の実施の形態】以下、本発明の実施の形態を図面
を参照して説明する。図１は、本発明の実施例１による
無効電力補償システムを示す構成図である。配電変電所
トランス１に接続された配電線２上で、電源側から離れ
た負荷側に近い位置に無効電力補償装置３、電源側に近
い位置に電圧調整器４が接続されている。また、配電線
２には、一般的な負荷５および大容量電動機のような瞬
時の電圧変動を発生させる負荷６が複数接続されてい
る。電圧調整器４は、図示していない巻線タップ切り換
え装置により、電圧調整器４の負荷側端の系統電圧を検
出し、その検出電圧が不感帯を有する上下限設定値を越
え、かつ所定の動作時限を経過したときに、昇圧または
降圧方向にタップ４０を切り換える。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a reactive power compensation system according to Embodiment 1 of the present invention. On the distribution line 2 connected to the distribution substation transformer 1, a reactive power compensator 3 is connected at a position near the load side away from the power supply side, and a voltage regulator 4 is connected at a position near the power supply side. In addition, a plurality of loads 6 such as a general load 5 and a large-capacity electric motor that generate instantaneous voltage fluctuations are connected to the distribution line 2. The voltage regulator 4 detects a system voltage at the load side end of the voltage regulator 4 by a winding tap switching device (not shown), and the detected voltage exceeds an upper / lower limit value having a dead zone and a predetermined operation. When the time limit has elapsed, the tap 40 is switched in the step-up or step-down direction.

【００２３】無効電力補償システムは無効電力補償装置
３と制御装置７より構成される。無効電力補償装置３
は、半導体スイッチ素子を用いて形成したインバータが
適用され、系統電圧を入力とする制御装置７からの制御
信号に基づいて、配電線に進みまたは遅れの無効電力を
出力する。The reactive power compensating system comprises a reactive power compensating device 3 and a control device 7. Reactive power compensator 3
Applies an inverter formed using a semiconductor switch element, and outputs a leading or lagging reactive power to a distribution line based on a control signal from a control device 7 which receives a system voltage as an input.

【００２４】制御装置７は、無効電力補償装置３が接続
された位置の電圧センサ８を介し、電圧検出回路９で検
出した系統電圧（設置点電圧）を入力する。この設置点
電圧の検出値より、特定電圧変動群抽出回路１０と補償
ゲイン回路１１を介して、電圧変動の特定の周波数成分
を補償するような無効電流指令値（または、無効電力指
令値）を出力する。補償ゲイン回路１１は、特定電圧変
動群抽出回路１０の出力に所定の補償ゲインを乗算し
て、無効電流指令を算出する。電流制御回路１２は、無
効電流指令値に対応する無効電流が無効電力補償装置３
から出力されるように、ＰＷＭ制御回路１３に制御信号
を出力する。ＰＷＭ制御回路１３は、制御信号に従って
インバータのゲートパルス信号を生成し、無効電力補償
装置３へ出力する。無効電力補償装置３はこのゲートパ
ルス信号に基づいて、所要の無効電力を発生する。この
ようにして、無効電力補償システムは、検出した配電線
電圧の電圧変動中の特定の周波数成分を補償するよう
に、電流制御回路１２を介して無効電力出力を制御す
る。The control device 7 inputs the system voltage (installation point voltage) detected by the voltage detection circuit 9 via the voltage sensor 8 at the position where the reactive power compensator 3 is connected. Based on the detected value of the installation point voltage, a reactive current command value (or a reactive power command value) for compensating a specific frequency component of the voltage fluctuation via the specific voltage fluctuation group extraction circuit 10 and the compensation gain circuit 11. Output. The compensation gain circuit 11 multiplies the output of the specific voltage fluctuation group extraction circuit 10 by a predetermined compensation gain to calculate a reactive current command. The current control circuit 12 outputs the reactive current corresponding to the reactive current command value to the reactive power compensator 3.
And outputs a control signal to the PWM control circuit 13 so as to output the control signal. The PWM control circuit 13 generates a gate pulse signal of the inverter according to the control signal, and outputs the generated signal to the reactive power compensator 3. The reactive power compensator 3 generates required reactive power based on the gate pulse signal. In this way, the reactive power compensation system controls the reactive power output via the current control circuit 12 so as to compensate for a specific frequency component in the detected fluctuation of the distribution line voltage.

【００２５】実施例１の無効電力補償システムは、電圧
変動の特定領域の周波数成分を抽出し、その周波数成分
の領域に応じて抽出ゲインの異なる特定電圧変動群抽出
回路１０を設けた制御装置７に特徴がある。すなわち、
特定電圧変動群抽出回路１０では、電圧検出回路９によ
り検出された無効電力補償装置３の設置点電圧に対し
て、瞬時変動抽出回路１４により、瞬時の電圧変動成分
を抽出し、この瞬時成分値に瞬時変動用のゲインＫ１を
抽出ゲイン１５にて乗算する。また、設置点電圧に対し
て、中間周波変動抽出回路１６により、瞬時電圧変動と
常時電圧変動の中間周波領域の変動である中間成分を抽
出して、この中間成分値に中間周波変動用のゲインＫ２
を抽出ゲイン１７にて乗算する。ゲインを乗算した後の
瞬時変動成分抽出値と中間周波変動抽出値は、加算器１
８により加算される。The reactive power compensating system according to the first embodiment extracts a frequency component in a specific region of voltage fluctuation, and includes a control device 7 provided with a specific voltage fluctuation group extraction circuit 10 having a different extraction gain according to the frequency component region. There is a feature. That is,
The specific voltage fluctuation group extraction circuit 10 extracts an instantaneous voltage fluctuation component from an installation point voltage of the reactive power compensating device 3 detected by the voltage detection circuit 9 by an instantaneous fluctuation extraction circuit 14. Is multiplied by an extraction gain 15 with a gain K1 for instantaneous fluctuation. The intermediate frequency fluctuation extracting circuit 16 extracts an intermediate component, which is a fluctuation in the intermediate frequency region between the instantaneous voltage fluctuation and the constant voltage fluctuation, with respect to the installation point voltage. K2
Is multiplied by an extraction gain 17. The instantaneous fluctuation component extraction value and the intermediate frequency fluctuation extraction value after multiplication by the gain are added to the adder 1
8 is added.

【００２６】このようにして、特定電圧変動群抽出回路
１０では、配電電圧からそれぞれ所定のゲインで抽出さ
れた瞬時変動成分と中間周波変動成分を加算した変動成
分が出力される。ここで、瞬時電圧変動とは少なくとも
電圧調整器の動作時限よりも短い時間の電圧変動で、数
十ミリ秒から数秒程度の時間で起きる電圧変動を表す。
また、常時電圧変動とは電圧調整器の調整動作が十分収
束する程度の時間に対応する電圧変動で、数分以上の電
圧変動を表す。In this manner, the specific voltage fluctuation group extraction circuit 10 outputs a fluctuation component obtained by adding the instantaneous fluctuation component and the intermediate frequency fluctuation component extracted from the distribution voltage with a predetermined gain. Here, the instantaneous voltage fluctuation is a voltage fluctuation at least for a time shorter than the operation time limit of the voltage regulator, and represents a voltage fluctuation occurring in a time of about several tens of milliseconds to several seconds.
Further, the constant voltage fluctuation is a voltage fluctuation corresponding to a time period in which the adjustment operation of the voltage regulator sufficiently converges, and represents a voltage fluctuation of several minutes or more.

【００２７】上述したように、特定電圧変動群抽出回路
１０と補償ゲイン回路１１は、瞬時変動と中間周波変動
を抽出して、その変動の周波数に応じて補償量を調整す
るような制御回路となっている。本実施例では、この瞬
時変動抽出と中間周波変動抽出に対する抽出周波数帯域
と抽出ゲインを、電圧調整器４の動作時限と不感帯幅と
に対応させて設定することにより、無効電力補償装置と
電圧調整器の補償分担を協調させることができ、分担過
程にかかる時間を短縮する。これにより、分担過程で生
じる瞬時電圧変化を最小限に抑えて、電圧調整器４へ補
償を分担させることができる。As described above, the specific voltage fluctuation group extraction circuit 10 and the compensation gain circuit 11 extract the instantaneous fluctuation and the intermediate frequency fluctuation, and adjust the compensation amount according to the frequency of the fluctuation. Has become. In the present embodiment, the extraction frequency band and the extraction gain for the instantaneous variation extraction and the intermediate frequency variation extraction are set in accordance with the operation time of the voltage regulator 4 and the dead band width, so that the reactive power compensator and the voltage regulator are adjusted. The coordination of the compensation of the devices can be coordinated, and the time required for the sharing process is reduced. This allows the voltage regulator 4 to share the compensation while minimizing the instantaneous voltage change that occurs in the sharing process.

【００２８】次に、特定電圧変動群抽出回路１０の詳細
な構成を説明する。特定電圧変動群抽出回路１０は瞬時
変動を抽出する瞬時変動抽出回路１４と抽出ゲイン１
５、瞬時と常時の間の中間周波変動を抽出する中間周波
変動抽出回路１６と抽出ゲイン１７、および加算器１８
によって構成される。瞬時変動抽出回路１４はカットオ
フ周波数以上の高域通過フィルタ１９により構成され
る。高域通過フィルタ１９はカットオフ周波数（＝１／
Ｔ１）以上の瞬時変動成分に対して０ｄＢ（＝１）のゲ
インをもち、それ以下の周波数に対しては周波数が低く
なるにつれゲインが減衰する特性をもつ。瞬時変動抽出
回路１４の出力は、抽出ゲイン１５によってゲインＫ１
を乗算されるので、結局、周波数１／Ｔ１以上の瞬時変
動成分は、ゲインＫ１倍で抽出されて、加算器１８に入
力される。Next, the detailed configuration of the specific voltage fluctuation group extraction circuit 10 will be described. The specific voltage fluctuation group extraction circuit 10 includes an instantaneous fluctuation extraction circuit 14 for extracting an instantaneous fluctuation and an extraction gain 1
5. Intermediate frequency fluctuation extracting circuit 16 for extracting intermediate frequency fluctuation between instantaneous and normal times, extraction gain 17, and adder 18
Composed of The instantaneous fluctuation extracting circuit 14 is constituted by a high-pass filter 19 having a cut-off frequency or higher. The high-pass filter 19 has a cut-off frequency (= 1 /
It has a characteristic of having a gain of 0 dB (= 1) for instantaneous fluctuation components equal to or longer than T1), and for a frequency lower than T1), the gain attenuates as the frequency becomes lower. The output of the instantaneous fluctuation extracting circuit 14 is output by a gain K1
After all, the instantaneous fluctuation component having a frequency equal to or higher than 1 / T1 is extracted by the gain K1 times and input to the adder 18.

【００２９】中間周波変動抽出回路１６は、カットオフ
周波数１／Ｔ２の低域通過フィルタ２０とカットオフ周
波数１／Ｔ３の高域通過フィルタ２１の直列回路によっ
て構成される。この直列回路全体の特性は、周波数１／
Ｔ２から周波数１／Ｔ３の周波数帯域をゲイン０ｄＢ
（＝１）で抽出する帯域通過フィルタとなっており、１
／Ｔ２から１／Ｔ３の周波数帯域が中間周波変動成分の
帯域に対応している。中間周波変動抽出回路１６の出力
は抽出ゲイン１７によってゲインＫ２を乗算されるの
で、結局、中間周波変動成分はゲインＫ２で抽出され
て、加算器１８に入力される。加算器１８では、ゲイン
Ｋ１で抽出された瞬時変動成分と、ゲインＫ２で抽出さ
れた中間周波変動成分とが加算されて、その結果が特定
電圧変動群抽出回路１０の出力となる。The intermediate frequency fluctuation extracting circuit 16 is constituted by a series circuit of a low-pass filter 20 having a cutoff frequency of 1 / T2 and a high-pass filter 21 having a cutoff frequency of 1 / T3. The characteristics of the whole series circuit are represented by the frequency 1 /
Gain of 0 dB in frequency band of frequency 1 / T3 from T2
(= 1) is a bandpass filter to be extracted.
The frequency band from / T2 to 1 / T3 corresponds to the band of the intermediate frequency fluctuation component. Since the output of the intermediate frequency fluctuation extraction circuit 16 is multiplied by the gain K2 by the extraction gain 17, the intermediate frequency fluctuation component is eventually extracted by the gain K2 and input to the adder 18. In the adder 18, the instantaneous fluctuation component extracted by the gain K 1 and the intermediate frequency fluctuation component extracted by the gain K 2 are added, and the result is output from the specific voltage fluctuation group extraction circuit 10.

【００３０】図２に、本実施例による特定電圧変動群抽
出回路の周波数抽出特性を示す。特定電圧変動群抽出回
路１０の電圧変動抽出特性で、横軸は周波数、縦軸は抽
出ゲインである。同図で、周波数１／Ｔ１以上が瞬時変
動の周波数領域であり、周波数１／Ｔ３以上１／Ｔ２以
下が中間周波変動の周波数領域である。ここで、特定電
圧変動群抽出回路１０の制御定数、すなわち抽出回路の
カットオフ周波数（または時定数）と抽出ゲインの設定
方法を説明する。FIG. 2 shows the frequency extraction characteristics of the specific voltage fluctuation group extraction circuit according to this embodiment. The horizontal axis indicates the frequency and the vertical axis indicates the extraction gain. In the figure, the frequency range of 1 / T1 or more is the frequency range of the instantaneous variation, and the frequency range of 1 / T3 or more and 1 / T2 or less is the frequency range of the intermediate frequency variation. Here, a control constant of the specific voltage fluctuation group extraction circuit 10, that is, a method of setting the cutoff frequency (or time constant) and the extraction gain of the extraction circuit will be described.

【００３１】抽出回路のカットオフ周波数は、それぞれ
瞬時変動抽出回路１４の高域通過フィルタのカットオフ
周波数１／Ｔ１、中間周波変動抽出回路１６の低域通過
フィルタのカットオフ周波数１／Ｔ２、高域通過フィル
タのカットオフ周波数１／Ｔ３である。１／Ｔ１は瞬時
変動領域を規定する定数であり、補償対象とする瞬時変
動の周波数範囲を考慮して設定される。通常、１／Ｔ１
は時定数Ｔ１を数秒から十数秒以下に設定する。The cutoff frequencies of the extraction circuit are as follows: the cutoff frequency 1 / T1 of the high-pass filter of the instantaneous fluctuation extraction circuit 14, the cutoff frequency 1 / T2 of the low-pass filter of the intermediate frequency fluctuation extraction circuit 16, and the high frequency. The cutoff frequency of the band-pass filter is 1 / T3. 1 / T1 is a constant that defines the instantaneous fluctuation region, and is set in consideration of the frequency range of the instantaneous fluctuation to be compensated. Usually 1 / T1
Sets the time constant T1 to several seconds to ten and several seconds or less.

【００３２】１／Ｔ２、１／Ｔ３は中間周波変動領域の
上限と下限を決める定数である。１／Ｔ２は、１／Ｔ２
＜１／Ｔ１を満たし、かつ時定数の差Ｔ２−Ｔ１が次の
条件を満たすように決められる。すなわち、Ｔ２−Ｔ１
は、瞬時変動領域から中間周波変動領域へ遷移するまで
の時間に対応しており、この時間に電圧が電圧調整器４
の不感帯レベルを越える値となるように調整させる。従
って、Ｔ２−Ｔ１はできるだけ短く、しかし、短時間の
電圧低下が配電線上の負荷に影響を与えないような許容
範囲（例えば、定格未満のあるレベルを維持できる範
囲）で設定される。本例では、Ｔ２−Ｔ１が数秒程度と
なるように、Ｔ２が設定される。1 / T2 and 1 / T3 are constants for determining the upper and lower limits of the intermediate frequency fluctuation region. 1 / T2 is 1 / T2
<1 / T1 is satisfied, and the time constant difference T2-T1 is determined to satisfy the following condition. That is, T2-T1
Corresponds to the time required for the transition from the instantaneous fluctuation region to the intermediate frequency fluctuation region.
Is adjusted so that the value exceeds the dead zone level. Therefore, T2−T1 is set as short as possible, but within an allowable range in which a short-time voltage drop does not affect the load on the distribution line (for example, a range where a certain level below the rating can be maintained). In this example, T2 is set so that T2-T1 is about several seconds.

【００３３】１／Ｔ３も時定数Ｔ３を基準にして設定さ
れる。Ｔ３は中間周波変動領域の終了時間に対応してお
り、これは無効電力補償装置３と電圧調整器４との過渡
的な補償分担が終了する時間に対応する。補償分担が終
了する時間は、対象とする瞬時電圧変動幅を電圧調整器
４のタップ調整の電圧幅で割り算した商（タップ切替回
数）に、電圧調整器４の動作時限をかけ算した結果とし
て見込むことができる。例えば、対象とする瞬時電圧変
動幅が５００Ｖ、電圧調整器４のタップ調整の電圧幅が
１００Ｖ、電圧調整器４の動作時限を１分とすると、補
償分担の終了時間は、約５分と見積もることができる。
Ｔ３は、補償分担終了時間に適当な余裕時間を足した値
とし、通常は数分程度に設定される。1 / T3 is also set based on the time constant T3. T3 corresponds to the end time of the intermediate frequency fluctuation region, which corresponds to the time when the transient compensation sharing between the reactive power compensator 3 and the voltage regulator 4 ends. The time at which the compensation sharing ends is expected as a result of multiplying the quotient (the number of times of tap switching) obtained by dividing the target instantaneous voltage fluctuation width by the voltage width of the tap adjustment of the voltage regulator 4 by the operation time limit of the voltage regulator 4. be able to. For example, assuming that the target instantaneous voltage fluctuation width is 500 V, the voltage width of tap adjustment of the voltage regulator 4 is 100 V, and the operation time of the voltage regulator 4 is 1 minute, the end time of compensation sharing is estimated to be about 5 minutes. be able to.
T3 is a value obtained by adding an appropriate margin time to the compensation sharing end time, and is usually set to about several minutes.

【００３４】次に、抽出ゲイン１５のゲインＫ１と抽出
ゲイン１７のゲインＫ２の設定法を説明する。ゲインＫ
１は瞬時変動成分に対するゲインであり、通常はＫ１＝
１、すなわち０ｄＢに設定される。ゲインＫ２は中間周
波変動成分に対するゲインであり、中間周波変動領域に
おいて電圧が電圧調整器４の不感帯レベルをわずかに越
えるように、抽出ゲインＫ２をＫ１に対して小さく設定
される。具体的には、補償対象とする瞬時電圧変動幅を
△Ｖとすると、△Ｖ・（Ｋ１−Ｋ２）が電圧調整器４の
不感帯幅を越えるように設定する。例えば、△Ｖ＝５０
０Ｖ、Ｋ１＝１、電圧調整器４の不感帯幅を１２０Ｖと
すると、Ｋ２は０．７６（＝−２．４ｄＢ）よりも小さ
くなるように設定される。なお、発生する瞬時電圧変動
幅△Ｖが一定しない場合には、その中で最大の変動幅も
しくは最も発生頻度の高い変動幅が△Ｖに設定される。Next, a method of setting the gain K1 of the extraction gain 15 and the gain K2 of the extraction gain 17 will be described. Gain K
1 is a gain for the instantaneous fluctuation component, and usually, K1 =
1, that is, set to 0 dB. The gain K2 is a gain for the intermediate frequency fluctuation component, and the extraction gain K2 is set smaller than K1 so that the voltage slightly exceeds the dead band level of the voltage regulator 4 in the intermediate frequency fluctuation region. Specifically, assuming that the instantaneous voltage fluctuation width to be compensated is ΔV, the setting is made such that ΔV · (K1−K2) exceeds the dead band width of the voltage regulator 4. For example, ΔV = 50
Assuming that 0 V, K1 = 1, and the dead band width of the voltage regulator 4 is 120 V, K2 is set to be smaller than 0.76 (= -2.4 dB). When the generated instantaneous voltage fluctuation width ΔV is not constant, the maximum fluctuation width or the fluctuation frequency with the highest frequency is set to ΔV.

【００３５】この特定電圧変動群抽出回路１０は以下の
ように動作する。周波数１／Ｔ１以上の瞬時変動の周波
数領域では、瞬時変動抽出回路１４と抽出ゲイン１５の
作用により、０ｄＢ（＝１）のゲインで、この領域の瞬
時成分が抽出される。周波数１／Ｔ３以上１／Ｔ２以下
が中間周波変動の周波数領域では、中間周波変動抽出回
路１６と抽出ゲイン１７の作用により、−ＸｄＢ（＝２
０ｌｏｇ（−Ｘ））のゲインで、この領域の中間成分が
抽出される。また、周波数１／Ｔ１以下と周波数１／Ｔ
２以上の領域は、０ｄＢと−ＸｄＢを結ぶ直線のゲイン
となるが、厳密には瞬時変動抽出回路１４及び中間周波
変動抽出回路１６の周波数特性と各々のゲインより決定
される。This specific voltage fluctuation group extraction circuit 10 operates as follows. In the frequency region of the instantaneous fluctuation of the frequency 1 / T1 or more, the instantaneous component of this region is extracted with the gain of 0 dB (= 1) by the operation of the instantaneous fluctuation extracting circuit 14 and the extraction gain 15. In a frequency region where the frequency is equal to or more than 1 / T3 and equal to or less than 1 / T2, the intermediate frequency fluctuation extracting circuit 16 and the extraction gain 17 cause the operation of -XdB (= 2
With a gain of 0 log (-X)), the intermediate component of this region is extracted. In addition, frequency 1 / T1 or less and frequency 1 / T
The two or more regions have the gain of a straight line connecting 0 dB and −X dB, but are strictly determined by the frequency characteristics of the instantaneous variation extraction circuit 14 and the intermediate frequency variation extraction circuit 16 and the respective gains.

【００３６】次に、本実施例による無効電力補償システ
ムの電圧変動補償動作を説明する。図３は、本無効電力
補償システムの補償動作を示す特性図で、横軸に時間、
縦軸に無効電力補償装置３の設置点電圧を示す。横軸に
平行した点線は、電圧調整器４の不感帯の下限レベルＶ
lowを表す。Next, the voltage fluctuation compensation operation of the reactive power compensation system according to this embodiment will be described. FIG. 3 is a characteristic diagram showing the compensation operation of the present reactive power compensation system.
The vertical axis indicates the installation point voltage of the reactive power compensator 3. The dotted line parallel to the horizontal axis is the lower limit level V of the dead zone of the voltage regulator 4.
Indicates low.

【００３７】ここで、電圧調整器４の動作について補足
する。電圧調整器４の動作は不感帯幅と動作時限によっ
て決められている。電圧調整器４はタップ４０の２次側
電圧を検出し、タップ２次側電圧が不感帯幅を越えた時
点からの時間が動作時限を越えるとタップが切り換わ
り、電圧が不感帯内へ入るように制御する。通常、不感
帯幅は定格電圧の数％、動作時限は３０秒〜２分程度に
設定される。なお、図３では、無効電力補償装置３の補
償動作の説明を容易にするために、電圧調整器４はタッ
プ固定（切り換えがない）の状態を仮定している。Here, the operation of the voltage regulator 4 will be supplemented. The operation of the voltage regulator 4 is determined by the dead zone width and the operation time limit. The voltage regulator 4 detects the secondary voltage of the tap 40, and when the time from the time when the tap secondary voltage exceeds the dead band exceeds the operation time limit, the tap is switched so that the voltage enters the dead band. Control. Usually, the dead zone width is set to several% of the rated voltage, and the operation time limit is set to about 30 seconds to 2 minutes. Note that, in FIG. 3, in order to facilitate the description of the compensation operation of the reactive power compensator 3, the voltage regulator 4 is assumed to be in a fixed tap state (no switching).

【００３８】まず時刻t0以前は、配電線電圧に変化のな
い定常状態にあり、図２の常時変動領域に対応する。常
時変動領域では抽出ゲインはほぼ０であり、無効電力補
償装置３の電圧補償量もほぼ０となっている。時刻t0に
おいて瞬時電圧低下が発生し、設置点電圧は瞬時（数ミ
リ秒程度）に△Ｖ低下する。この時刻t0直後からt1の時
間は瞬時変動領域に対応し、ゲイン＝１で抽出されるた
め、無効電力補償装置３の補償量も大きく、電圧は瞬時
に元のレベルまで回復される。Before time t0, the distribution line voltage is in a steady state with no change, and corresponds to the constantly fluctuating region in FIG. In the constant fluctuation region, the extraction gain is almost 0, and the voltage compensation amount of the reactive power compensator 3 is also almost 0. At time t0, an instantaneous voltage drop occurs, and the installation point voltage instantaneously (about several milliseconds) drops by ΔV. Immediately after this time t0, the time t1 corresponds to the instantaneous fluctuation region and is extracted with the gain = 1, so that the compensation amount of the reactive power compensator 3 is large, and the voltage is instantaneously restored to the original level.

【００３９】時刻t1からt2の時間は、瞬時変動領域と中
間周波変動領域の間の領域に相当する。図２のように、
この周波数領域での抽出ゲインは減衰する特性をもつの
で、無効電力補償装置３の補償量も時間とともに減少す
る。この結果、電圧も低下し、時刻t2において電圧調整
器４の不感帯下限レベルＶlowをわずかに越える値まで
下がる。ここで、t1からt2の時間幅は、短時間の電圧低
下が配電線上の機器に影響を与えない範囲で、短く設定
される（数秒程度）。すなわち、t1からt2の電圧の低下
は時定数Ｔ１と時定数Ｔ２から定まり、前半は主にＴ１
によって急に低下し、後半は主にＴ２によって緩やかな
低下となる。この結果、配電線電圧を電圧調整器４の不
感帯下限レベルＶlowまで速く調整でき、その分、電圧
調整器４の補償分担を速やかに開始できる。The time from time t1 to time t2 corresponds to a region between the instantaneous fluctuation region and the intermediate frequency fluctuation region. As shown in FIG.
Since the extraction gain in this frequency domain has an attenuating characteristic, the compensation amount of the reactive power compensator 3 also decreases with time. As a result, the voltage also drops, and at time t2, drops to a value that slightly exceeds the dead zone lower limit level Vlow of the voltage regulator 4. Here, the time width from t1 to t2 is set short (about several seconds) within a range in which a short-time voltage drop does not affect devices on the distribution line. That is, the voltage drop from t1 to t2 is determined by the time constant T1 and the time constant T2, and the first half is mainly T1
, And in the latter half, it gradually decreases mainly due to T2. As a result, the distribution line voltage can be quickly adjusted to the dead band lower limit level Vlow of the voltage regulator 4, and the compensation sharing of the voltage regulator 4 can be promptly started.

【００４０】時刻t2からt3の時間は中間周波変動の領域
に対応する。この領域での抽出ゲインは一定に保持さ
れ、無効電力補償装置３の補償量も一定となる。この結
果、電圧は電圧調整器４の不感帯下限レベルをわずかに
越えた値を維持する。無効電力補償装置３と電圧調整器
４との過渡的な補償分担は、この期間において動作時限
に達すると実施される。電圧は、電圧調整器４の不感帯
下限レベルをわずかに越えた値に維持されるため、補償
分担過程における電圧変化は必要最小限に抑えられる。The time from the time t2 to the time t3 corresponds to the region of the intermediate frequency fluctuation. The extraction gain in this region is kept constant, and the compensation amount of the reactive power compensator 3 is also constant. As a result, the voltage maintains a value slightly exceeding the dead band lower limit level of the voltage regulator 4. Transient compensation sharing between the reactive power compensator 3 and the voltage regulator 4 is performed when the operation time limit is reached during this period. Since the voltage is maintained at a value slightly exceeding the dead band lower limit level of the voltage regulator 4, the voltage change in the compensation sharing process is minimized.

【００４１】時刻t3以降の時間は、常時変動領域に対応
する。常時変動領域では、特定電圧変動抽出回路１０の
抽出ゲインは主に時定数Ｔ３によって下降し、ほぼ０と
なる。従って、無効電力補償装置３の補償量も減少し、
もし電圧調整器４がなければ、電圧は最終的に変動直後
の電圧レベルまで下がる。The time after time t3 always corresponds to the variable region. In the constant fluctuation region, the extraction gain of the specific voltage fluctuation extraction circuit 10 decreases mainly due to the time constant T3 and becomes almost zero. Therefore, the compensation amount of the reactive power compensator 3 also decreases,
If there is no voltage regulator 4, the voltage will eventually drop to the voltage level just after the fluctuation.

【００４２】このように、本実施例の無効電力補償シス
テムでは、瞬時電圧変動はまず高いゲインで抽出され高
速に補償される。その後、抽出ゲインが低下し、配電線
上の他の負荷に影響を与えない範囲の短時間で、電圧は
電圧調整器４の不感帯を越えるレベルまで戻される。そ
して中間周波変動領域に対応する時間領域では、抽出ゲ
インは一定となり、電圧は電圧調整器４の不感帯をわず
かに越えたレベルに維持されて、電圧調整器４との間で
過渡的に補償分担が実施される。すなわち、無効電力補
償装置３は、電圧調整器４との過渡的な補償分担におい
て、短時間で分担を開始し、かつ分担の過程で電圧を必
要以上に変化させないように動作する。As described above, in the reactive power compensation system according to the present embodiment, the instantaneous voltage fluctuation is first extracted with a high gain and compensated at high speed. Thereafter, the voltage is returned to a level exceeding the dead zone of the voltage regulator 4 in a short time within a range in which the extraction gain decreases and does not affect other loads on the distribution line. Then, in the time domain corresponding to the intermediate frequency fluctuation domain, the extraction gain becomes constant, the voltage is maintained at a level slightly exceeding the dead zone of the voltage regulator 4, and the voltage is transiently compensated and shared with the voltage regulator 4. Is performed. In other words, the reactive power compensator 3 starts the sharing in a short time in the transient compensation sharing with the voltage regulator 4, and operates so as not to change the voltage more than necessary in the sharing process.

【００４３】次に、電圧調整器４が実際に電圧調整動作
する場合の補償分担過程を説明する。図４は、本実施例
の無効電力補償システムにおける無効電力補償装置と電
圧調整器の補償分担動作で、横軸は時間軸、縦軸は配電
線電圧を示す。なお、斜線の領域は、無効電力補償装置
３が補償分担している電圧量を表している。Next, a description will be given of the compensation sharing process when the voltage regulator 4 actually performs the voltage regulating operation. FIG. 4 shows the compensation sharing operation of the reactive power compensating device and the voltage regulator in the reactive power compensating system of the present embodiment. The horizontal axis represents the time axis, and the vertical axis represents the distribution line voltage. The shaded area represents the amount of voltage that the reactive power compensator 3 is sharing for compensation.

【００４４】時刻t0において、瞬時電圧変動が発生し、
瞬時電圧低下が発生する。時刻t0からt1において、無効
電力補償装置３は瞬時変動抽出回路１４および抽出ゲイ
ン１５の作用により、電圧変動を瞬時に補償する。時刻
t1からt2において、この時間は瞬時変動と中間周波変動
に対応するため、図３に説明したように無効電力補償装
置３の補償量が減少し、電圧は電圧調整器４の不感帯レ
ベルを越える値まで戻される。時刻t2からt7までの時間
が中間周波変動領域に対応し、この期間で電圧調整器４
との過渡的な補償分担がなされる。At time t0, an instantaneous voltage fluctuation occurs,
Instantaneous voltage drop occurs. From time t0 to t1, the reactive power compensator 3 instantaneously compensates for voltage fluctuations by the action of the instantaneous fluctuation extraction circuit 14 and the extraction gain 15. Times of Day
From time t1 to time t2, this time corresponds to the instantaneous fluctuation and the intermediate frequency fluctuation, so that the amount of compensation of the reactive power compensator 3 decreases as described with reference to FIG. 3, and the voltage exceeds the dead band level of the voltage regulator 4. Returned to The time from time t2 to t7 corresponds to the intermediate frequency fluctuation region, and during this period, the voltage regulator 4
And the transient compensation sharing.

【００４５】まず時刻t2からt3において、電圧は電圧調
整器４の不感帯レベルをわずかに越えるレベルに維持さ
れる。ここで、時刻t2からt3までの時間長は電圧調整器
４の動作時限に等しい。電圧が不感帯レベルを越えて動
作時限分の時間が経過した時刻t3において、電圧調整器
４は電圧を不感帯内に戻そうと電圧を上げる方向にタッ
プを切り換える。この結果、瞬時に電圧が上がるが、無
効電力補償装置３が、これを瞬時電圧変動とみなして、
瞬時に補償するため、電圧は元のレベルに維持される。
この時、斜線で示された無効電力補償装置３の電圧補償
量は、電圧調整器４の１タップ分減少する。すなわち、
無効電力補償装置３から電圧調整器４へ、電圧調整器４
における１タップの電圧補償分が過渡的に分担されてい
る。First, from time t2 to t3, the voltage is maintained at a level slightly exceeding the dead zone level of the voltage regulator 4. Here, the time length from time t2 to t3 is equal to the operation time limit of the voltage regulator 4. At time t3 when the voltage exceeds the dead zone level and the operation time period elapses, the voltage regulator 4 switches the tap in the direction of increasing the voltage to return the voltage to the dead zone. As a result, the voltage rises instantaneously, but the reactive power compensator 3 regards this as an instantaneous voltage fluctuation,
The voltage is maintained at its original level for instantaneous compensation.
At this time, the amount of voltage compensation of the reactive power compensator 3 shown by hatching is reduced by one tap of the voltage regulator 4. That is,
From the reactive power compensator 3 to the voltage regulator 4, the voltage regulator 4
, The voltage compensation of one tap is transiently shared.

【００４６】時刻t3からt4では、時刻t2からt3と同じ現
象が起きている。すなわち、電圧が不感帯レベルを越え
て動作時限分の時間が経過したため、時刻t4において、
電圧調整器４がタップを切り換え、これによる電圧変化
を無効電力補償装置３が補償する。その結果、時刻t4後
は、合わせて２タップの電圧補償分が電圧調整器４へ分
担されている。時刻t4からt5、時刻t5からt6でも、時刻
t2からt3と同じ現象が起きており、無効電力補償装置３
から電圧調整器４へ、電圧調整器４の１タップ分ずつ電
圧補償分が過渡的に分担されていく。そして、時刻t6に
おいて、無効電力補償装置３のすべての電圧補償分が電
圧調整器４へと分担されて、補償分担過程が完了する。From time t3 to t4, the same phenomenon as from time t2 to t3 occurs. That is, since the voltage has exceeded the dead zone level and the operation time has elapsed, at time t4,
The voltage regulator 4 switches the tap, and the reactive power compensator 3 compensates for the voltage change due to the switching. As a result, after time t4, a voltage compensation amount of two taps is shared by the voltage regulator 4 in total. Even from time t4 to t5 and from time t5 to t6, the time
The same phenomenon has occurred from t2 to t3, and the reactive power compensator 3
, The voltage compensation is transiently assigned to the voltage regulator 4 by one tap of the voltage regulator 4. Then, at time t6, all the voltage compensation components of the reactive power compensator 3 are shared by the voltage regulator 4, and the compensation sharing process is completed.

【００４７】この時刻t0からt6までの無効電力補償装置
３の補償開始から補償分担終了までの間に要した時間
は、電圧調整器４の動作時限の４倍にほぼ等しい。時刻
t0で発生した電圧変動△Ｖは、電圧調整器４の４タップ
分の電圧変動幅のため、電圧調整器４に補償分担させる
には、少なくとも４回のタップ動作が必要になる。図４
の補償分担では、ほぼ最短の時間で電圧調整器４への分
担を完了している。さらに、分担過程で発生した電圧変
化は、電圧調整器４の不感帯レベルをわずかに越えるレ
ベルに保持され、必要最小限に抑えられている。The time required from the start of the compensation of the reactive power compensator 3 until the end of the compensation sharing from the time t0 to the time t6 is substantially equal to four times the operation time of the voltage regulator 4. Times of Day
Since the voltage fluctuation ΔV generated at t0 is a voltage fluctuation width of four taps of the voltage regulator 4, at least four tap operations are required to allow the voltage regulator 4 to share the compensation. FIG.
In the compensation sharing, the assignment to the voltage regulator 4 is completed in almost the shortest time. Further, the voltage change generated in the sharing process is maintained at a level slightly exceeding the dead zone level of the voltage regulator 4 and is kept to a minimum.

【００４８】本実施例では、配電線上に複数の瞬時電圧
変動発生負荷６が存在する場合の電圧安定化に有効であ
る。例えば、１つ目の瞬時電圧変動発生負荷６が時刻t0
で動作すると、無効電力補償装置３はほぼ最短時間の時
刻t6までに電圧調整器４との補償分担を完了し、時刻t6
以降に２つ目の瞬時電圧変動発生負荷６が動作するとし
ても、100%の補償量で補償することが可能になる。ま
た、２つ目の瞬時電圧変動が時刻t6以前、例えば、時刻
t4からt5期間に生じた場合でも、時刻t4以前の補償分担
作用によって、電圧調整器４の２タップ分の補償量が無
効電力補償装置３に確保されている。従って、２つ目の
瞬時電圧変動に対しては、２タップ分の瞬時変動を補償
することができるので、配電線上の電圧変動を抑制でき
る。The present embodiment is effective for voltage stabilization when a plurality of instantaneous voltage fluctuation generating loads 6 exist on a distribution line. For example, the first instantaneous voltage fluctuation generating load 6 is at time t0
, The reactive power compensator 3 completes the compensation sharing with the voltage regulator 4 by the time t6, which is almost the shortest time, and the time t6
Thereafter, even if the second instantaneous voltage fluctuation generating load 6 operates, it is possible to compensate with a 100% compensation amount. In addition, the second instantaneous voltage fluctuation occurs before time t6, for example, at time t6.
Even when the period occurs from t4 to t5, the compensation amount for two taps of the voltage regulator 4 is secured in the reactive power compensator 3 by the compensation sharing operation before time t4. Therefore, for the second instantaneous voltage fluctuation, the instantaneous fluctuation for two taps can be compensated, so that the voltage fluctuation on the distribution line can be suppressed.

【００４９】以上説明したように、本実施例の特定電圧
変動群抽出回路１０の作用により、無効電力補償装置３
から電圧調整器４への過渡的な補償分担に要する時間を
ほぼ最短の時間長に短縮することができ、かつその過程
で生じる電圧変化を必要最小の変化幅に抑えることがで
きる。その結果、複数の瞬時電圧変動負荷が接続して、
瞬時電圧変動が連続的に発生するような配電線において
も、無効電力補償装置３は、補償量を十分、もしくはあ
る程度確保した状態で次の瞬時変動を補償することがで
き、配電線上の他の負荷に及ぼす障害を回避ないし軽減
できる。As described above, the reactive power compensator 3 is operated by the operation of the specific voltage fluctuation group extracting circuit 10 of this embodiment.
Thus, the time required for the transient compensation sharing to the voltage regulator 4 can be shortened to the shortest time length, and the voltage change occurring in the process can be suppressed to the minimum required change width. As a result, multiple instantaneous voltage fluctuation loads are connected,
Even in a distribution line in which instantaneous voltage fluctuations occur continuously, the reactive power compensator 3 can compensate for the next instantaneous fluctuations in a state where the amount of compensation is sufficient or secured to some extent, and other reactive lines on the distribution line can be compensated. Obstacles affecting the load can be avoided or reduced.

【００５０】図５、本発明の第２の実施例による無効電
力補償システムの構成図を示す。図１と同等の要素には
同一符号を付して説明を省略する。図１の実施例と異な
る点は、特定電圧変動群抽出回路１０において、瞬時変
動領域と中間周波変動領域をそれぞれ所定のゲインで抽
出する階段状周波数特性フィルタ２２を用いたことにあ
る。FIG. 5 shows a configuration diagram of a reactive power compensation system according to a second embodiment of the present invention. Elements that are the same as in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. The difference from the embodiment of FIG. 1 is that the specific voltage fluctuation group extraction circuit 10 uses a step-like frequency characteristic filter 22 that extracts the instantaneous fluctuation region and the intermediate frequency fluctuation region with a predetermined gain.

【００５１】本実施例における階段状周波数特性フィル
タ２２の変動抽出特性は図２の特性と同じであり、瞬時
変動領域と中間周波変動領域を所定のゲインで抽出する
階段状の周波数特性を有している。ゲインの設定は上述
した通りである。これによれば、図１の実施例と同様の
効果が得られるとともに、特定電圧変動群抽出回路２２
が一つの要素で構成されるため構成を簡単にできる。さ
らに、図１の複数要素構成の場合に懸念される干渉作用
が発生しないという効果がある。The variation extraction characteristic of the stepped frequency characteristic filter 22 in this embodiment is the same as the characteristic shown in FIG. 2, and has a stepped frequency characteristic for extracting the instantaneous fluctuation region and the intermediate frequency fluctuation region with a predetermined gain. ing. The setting of the gain is as described above. According to this, the same effect as that of the embodiment of FIG. 1 can be obtained, and the specific voltage fluctuation group extraction circuit 22
Is composed of one element, so that the configuration can be simplified. Further, there is an effect that the interference effect which is a concern in the case of the multiple element configuration of FIG. 1 does not occur.

【００５２】図６、本発明の第３の実施例による無効電
力補償システムの構成図を示す。ここでも、図１と同等
の要素には同一符号を付して説明を省略する。図１の実
施例と異なる点は、特定電圧変動群抽出回路１０と補償
ゲイン１１との間に不感帯回路２３を設けたことにあ
る。FIG. 6 shows a configuration diagram of a reactive power compensation system according to a third embodiment of the present invention. Here, the same reference numerals are given to the same components as those in FIG. 1 and the description is omitted. The difference from the embodiment of FIG. 1 lies in that a dead zone circuit 23 is provided between the specific voltage fluctuation group extraction circuit 10 and the compensation gain 11.

【００５３】不感帯回路２３は、入力が設定されている
不感帯幅内にあれば０を出力し、不感帯を越えると入力
をそのまま出力する。この不感帯回路２３は、常時の電
圧変動における電圧調整器４のタップ動作に対し、無効
電力補償装置３が不要な動作をするのを、以下のように
防止する。The dead zone circuit 23 outputs 0 if the input is within the set dead zone width, and outputs the input as it is when the input exceeds the dead zone. The dead zone circuit 23 prevents the reactive power compensator 3 from performing an unnecessary operation in response to a tap operation of the voltage regulator 4 in a constant voltage fluctuation as follows.

【００５４】まず不感帯回路２３が無い場合を考える。
日負荷変動のような１日周期のゆっくりとした負荷変動
による常時の電圧変動に対して、電圧調整器４はタップ
を切り換えて電圧を調整する。このタップ切り換えによ
るステップ状の電圧変化が、無効電力補償装置３の特定
電圧変動郡抽出回路１０内の瞬時変動抽出回路１４で抽
出されるため、瞬時の電圧変動が発生したとみなされ
て、無効電力補償装置３は補償を行う。First, consider the case where there is no dead zone circuit 23.
The voltage regulator 4 adjusts the voltage by switching taps with respect to a constant voltage fluctuation due to a slow load fluctuation in a one-day cycle such as a daily load fluctuation. Since the step-like voltage change due to the tap switching is extracted by the instantaneous variation extraction circuit 14 in the specific voltage variation group extraction circuit 10 of the reactive power compensator 3, it is considered that an instantaneous voltage variation has occurred, and The power compensation device 3 performs compensation.

【００５５】しかし、この無効電力補償装置３の補償動
作は全く不要な動作であり、この不要動作期間中に、本
来対象としている瞬時電圧変動が起こった場合、補償量
が不足して、瞬時電圧変動を補償しきれなくなるという
可能性がある。また、この不要動作期間中は、無効電力
補償装置３は運転による電力損失が増大しており、これ
も本来不要な損失が生じていることになる。However, the compensation operation of the reactive power compensator 3 is completely unnecessary operation. If the intended instantaneous voltage fluctuation occurs during the unnecessary operation period, the compensation amount is insufficient and the instantaneous voltage There is a possibility that the fluctuations cannot be compensated. Further, during the unnecessary operation period, the power loss due to the operation of the reactive power compensator 3 is increasing, and this also means that the unnecessary loss occurs.

【００５６】図６の不感帯回路２３がある場合、不感帯
幅は正側、負側とも電圧調整器４の１タップの電圧変化
より大きい値に設定する。通常１タップは100V程度なの
で、不感帯幅は±100Vを越える値に設定する。不感帯回
路２３は入力、すなわち特定電圧変動郡抽出回路１０か
らの出力が、不感帯幅内の値であれば０を出力し、不感
帯幅を越える値の場合は入力と同じ値を出力する。When the dead band circuit 23 shown in FIG. 6 is provided, the dead band width is set to a value larger than the voltage change of one tap of the voltage regulator 4 on both the positive side and the negative side. Usually, one tap is about 100V, so the dead zone width is set to a value exceeding ± 100V. The dead zone circuit 23 outputs 0 if the input, that is, the output from the specific voltage fluctuation group extraction circuit 10, is within the dead zone width, and outputs the same value as the input if the value exceeds the dead zone width.

【００５７】このような不感帯回路２３を設けることに
より、常時の電圧変動を調整するための電圧調整器４の
タップ切り換えによる電圧変化が、無効電力補償装置３
の特定電圧変動郡抽出回路１０内の瞬時変動抽出回路１
４で抽出されても、その抽出値は不感帯幅内のため、不
感帯回路２３の出力は０となり、無効電力補償装置３は
補償出力をしない。また、無効電力補償装置３の補償対
象としている瞬時電圧変動は、電圧調整器４の１タップ
の電圧変化より十分大きく、従って不感帯回路２３の不
感帯幅よりも大きいため、このような瞬時電圧変動が発
生した場合には、特定電圧変動郡抽出回路１０内の瞬時
変動抽出回路１４の出力は、不感帯回路２３を通してそ
のまま補償ゲイン１１へ入力され、補償動作が行われ
る。By providing such a dead zone circuit 23, a voltage change due to a tap change of the voltage regulator 4 for adjusting the voltage fluctuation at all times is suppressed by the reactive power compensator 3.
Instantaneous fluctuation extracting circuit 1 in the specific voltage fluctuation group extracting circuit 10
4, the output of the dead band circuit 23 is 0 because the extracted value is within the dead band width, and the reactive power compensator 3 does not perform compensation output. Further, the instantaneous voltage fluctuation to be compensated by the reactive power compensator 3 is sufficiently larger than the voltage change of one tap of the voltage regulator 4 and is therefore larger than the dead band width of the dead band circuit 23. When this occurs, the output of the instantaneous fluctuation extraction circuit 14 in the specific voltage fluctuation group extraction circuit 10 is directly input to the compensation gain 11 through the dead band circuit 23, and the compensation operation is performed.

【００５８】図７に、不感帯回路２３の入出力特性を示
す。同図（ａ）は、上記にて説明した通りの入出力特性
を表している。横軸は入力ｘ、縦軸は出力ｙを表し、不
感帯幅は正側Ｔ＋から負側Ｔ−までの領域となってい
る。入力ｘがＴ−≦ｘ≦Ｔ＋ならばｙ＝０、ｘ＜Ｔ−ま
たはｘ＞Ｔ＋ならばｙ＝ｘとなる。FIG. 7 shows the input / output characteristics of the dead zone circuit 23. FIG. 11A shows the input / output characteristics as described above. The horizontal axis represents the input x and the vertical axis represents the output y, and the dead zone width is a region from the positive side T + to the negative side T−. If the input x is T− ≦ x ≦ T +, y = 0, and if x <T− or x> T +, y = x.

【００５９】図７（ｂ）は、不感帯回路２３の異なる入
出力特性例で、ヒステリシス特性を示している。例え
ば、入力ｘが不感帯正側のＴ＋を越えた場合、不感帯回
路２３の出力ｙはｘが負の値Ｒ＋を負側に越えるまで、
ｙ＝ｘの特性を保持する。そして、ｘが負の値Ｒ＋より
小さくなるとｙ＝０となり、不感帯幅を越える前の状態
に戻る。また入力ｘが不感帯負側のＴ−を負側に越えた
場合、不感帯回路２３の出力ｙはｘが正の値Ｒ−を正側
に越えるまで、ｙ＝ｘの特性を保持する。FIG. 7B shows a hysteresis characteristic of an example of different input / output characteristics of the dead band circuit 23. For example, if the input x exceeds T + on the positive side of the dead zone, the output y of the dead zone circuit 23 will not change until x exceeds the negative value R + to the negative side.
The characteristic of y = x is maintained. When x becomes smaller than the negative value R +, y = 0, and the state returns to the state before the dead band width is exceeded. When the input x exceeds the negative side of the dead zone T− to the negative side, the output y of the dead zone circuit 23 holds the characteristic of y = x until x exceeds the positive value R− to the positive side.

【００６０】このような特性をもつことにより、入力ｘ
が正または負側に不感帯を越えた後、再び不感帯幅の中
に入っても、出力が０に急変することなく、連続的に変
化するようになる。従って、（ａ）の場合は出力の急変
を避けるため、不感帯幅を大きく拡げることはできなか
ったが、（ｂ）の場合は電圧調整器４のタップ切り換え
に対する不要動作を避けるように、不感帯幅を大きく拡
げて設定することができる。By having such characteristics, the input x
After the crossover of the dead band on the positive or negative side, the output continuously changes without suddenly changing to zero even if the signal again enters the dead band width. Therefore, in the case of (a), the dead band width could not be widened greatly in order to avoid a sudden change in the output. However, in the case of (b), the dead band width was set so as to avoid unnecessary operation for the tap change of the voltage regulator 4. Can be greatly expanded and set.

【００６１】以上のように、第３の実施例によれば、図
１の実施例で得られる効果に加えて、常時電圧変動時の
電圧調整器のタップ動作に対する無効電力補償装置の不
要動作を防止できるため、瞬時電圧変動に対する補償容
量の確保と装置運転損失の低減という効果が得られる。As described above, according to the third embodiment, in addition to the effects obtained in the embodiment of FIG. 1, the unnecessary operation of the reactive power compensator for the tap operation of the voltage regulator when the voltage is constantly fluctuated. Therefore, it is possible to obtain the effect of securing the compensation capacity for the instantaneous voltage fluctuation and reducing the device operation loss.

【００６２】図８に、本発明の第４の実施例による無効
電力補償システムの構成図を示す。図１と同等の要素に
は同一符号を付して説明を省略する。本実施例では、図
１の構成に加えて、電流センサ２４、系統電圧変動推定
回路２５、系統電圧変動分析回路２６、制御設定値演算
回路２７、時刻情報出力回路２８、配電線電圧変動デー
タベース２９及び外部出力回路３０を設けている。FIG. 8 shows a configuration diagram of a reactive power compensation system according to a fourth embodiment of the present invention. Elements that are the same as in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. In this embodiment, in addition to the configuration of FIG. 1, a current sensor 24, a system voltage fluctuation estimating circuit 25, a system voltage fluctuation analyzing circuit 26, a control set value calculating circuit 27, a time information output circuit 28, a distribution line voltage fluctuation database 29 And an external output circuit 30.

【００６３】電流センサ２４は、無効電力補償装置３の
出力電流値Icを検出する。出力電流値Icと電圧検出回路
９から出力される電圧検出値Ｖが系統電圧変動推定回路
２５に入力される。系統電圧変動推定回路２５では、電
圧検出値Ｖより、無効電力補償装置３による電圧補償分
Ｘ×Ic項を引き算して、無効電力補償装置３が補償しな
かった場合の配電線の電圧変動値を演算により推定す
る。系統電圧変動分析回路２６では、電圧変動推定値よ
り瞬時電圧変動成分が抽出されて、瞬時電圧変動の大き
さと変動の継続時間が演算により求められる。制御設定
値演算回路２７では、系統電圧変動分析回路２６で求め
られた瞬時電圧変動の大きさと変動の継続時間より、こ
の瞬時変動を抑制するのに適した制御設定値が演算され
る。The current sensor 24 detects an output current value Ic of the reactive power compensator 3. The output current value Ic and the detected voltage value V output from the voltage detection circuit 9 are input to the system voltage fluctuation estimation circuit 25. The system voltage fluctuation estimating circuit 25 subtracts the voltage compensation value X × Ic term by the reactive power compensator 3 from the detected voltage V, and the voltage fluctuation value of the distribution line when the reactive power compensator 3 does not compensate. Is estimated by calculation. In the system voltage fluctuation analysis circuit 26, the instantaneous voltage fluctuation component is extracted from the estimated voltage fluctuation value, and the magnitude of the instantaneous voltage fluctuation and the duration of the fluctuation are calculated. The control set value calculation circuit 27 calculates a control set value suitable for suppressing the instantaneous fluctuation from the magnitude of the instantaneous voltage fluctuation obtained by the system voltage fluctuation analysis circuit 26 and the duration of the fluctuation.

【００６４】ここで、演算される制御設定値は、第１の
実施例における図１の瞬時変動抽出回路１９の時定数Ｔ
１、中間周波変動抽出回路１６の時定数Ｔ２、Ｔ３およ
び抽出ゲイン１５のＫ１、抽出ゲイン１７のＫ２があ
る。制御定数の設定は、第１の実施例で説明した方法と
同様である。制御設定値演算回路２７で設定された制御
定数は、特定電圧変動群抽出回路１０に入力されて、各
々の制御定数が更新される。また、系統電圧変動推定回
路２５で、推定された電圧変動値は、時刻情報出力回路
２８の時刻情報出力と合わせて配電線電圧変動データベ
ース２９に蓄積される。外部出力回路３０は配電線電圧
変動データベース２９の蓄積データを外部へ出力する。Here, the calculated control set value is the time constant T of the instantaneous variation extraction circuit 19 of FIG.
1. There are time constants T2 and T3 of the intermediate frequency fluctuation extraction circuit 16, K1 of the extraction gain 15, and K2 of the extraction gain 17. The setting of the control constant is the same as the method described in the first embodiment. The control constants set by the control set value calculation circuit 27 are input to the specific voltage fluctuation group extraction circuit 10, and the respective control constants are updated. Further, the voltage fluctuation value estimated by the system voltage fluctuation estimation circuit 25 is stored in the distribution line voltage fluctuation database 29 together with the time information output of the time information output circuit 28. The external output circuit 30 outputs the stored data of the distribution line voltage fluctuation database 29 to the outside.

【００６５】以上のように、第４の実施例では、系統電
圧変動推定回路２５、系統電圧変動分析回路２６、制御
設定値演算回路２７を通じて、無効電力補償装置３が設
置された配電線の瞬時電圧変動を演算により検出し、こ
れを用いて制御設定値を自動で更新できるようにしてい
る。これによれば、無効電力補償装置３が設置された配
電線の瞬時電圧変動発生状況に応じた制御を実施するこ
とができるという効果がある。さらに、電圧変動データ
をデータベース化して、外部にデータを出力できるよう
にしているので、配電線の電圧管理者が配電線の電圧変
動状況を確認できると共に、この電圧変動データを基に
制御設定値を見直して、より適した制御設定値に変更す
ることができるという効果がある。As described above, in the fourth embodiment, the system voltage fluctuation estimating circuit 25, the system voltage fluctuation analyzing circuit 26, and the control set value calculating circuit 27 are used to instantaneously control the distribution line on which the reactive power compensator 3 is installed. Voltage fluctuation is detected by calculation, and the control set value can be automatically updated using the detected voltage fluctuation. According to this, there is an effect that control according to the instantaneous voltage fluctuation occurrence state of the distribution line on which the reactive power compensator 3 is installed can be performed. Furthermore, since the voltage fluctuation data is stored in a database so that data can be output to the outside, the voltage manager of the distribution line can check the voltage fluctuation status of the distribution line and control set values based on this voltage fluctuation data. Has an effect that the control setting value can be changed to a more suitable control set value.

【００６６】[0066]

【発明の効果】本発明によれば、無効電力補償システム
から電圧調整器への過渡的な補償分担をほぼ最短の時間
長に短縮し、かつその過程で生じる電圧変化を必要最小
の変化幅に抑えるので、無効電力補償システムの補償量
を確保して次の瞬時変動に備えることができ、瞬時電圧
変動が連続的に発生するような配電線の電圧を信頼性高
く安定化する効果がある。According to the present invention, the transient compensation sharing from the reactive power compensation system to the voltage regulator is shortened to the shortest time length, and the voltage change occurring in the process is reduced to the required minimum change width. Therefore, the compensation amount of the reactive power compensation system can be secured to prepare for the next instantaneous fluctuation, and there is an effect that the voltage of the distribution line in which the instantaneous voltage fluctuation continuously occurs is stabilized with high reliability.

【００６７】また、常時電圧変動時の電圧調整器のタッ
プ動作に対する無効電力補償システムの不要動作を防止
できるため、瞬時電圧変動の発生に備えて無効電力補償
システムの補償容量を確保することができ、かつ運転損
失を低減することができる。Further, unnecessary operation of the reactive power compensating system with respect to the tap operation of the voltage regulator at the time of constant voltage fluctuation can be prevented, so that the compensation capacity of the reactive power compensating system can be secured in preparation for occurrence of instantaneous voltage fluctuation. , And operation loss can be reduced.

【００６８】さらに、無効電力補償システムが設置され
た配電線の電圧変動推定値を基にして、無効電力補償シ
ステムの制御装置の制御定数を適宜設定変更できるた
め、その配電線の瞬時電圧変動発生状況に適した制御を
実施することができる。Further, since the control constant of the control device of the reactive power compensation system can be appropriately changed based on the estimated value of the voltage variation of the distribution line in which the reactive power compensation system is installed, the instantaneous voltage fluctuation of the distribution line can be changed. Control suitable for the situation can be performed.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の第１の実施例による無効電力補償シス
テムの全体構成図。FIG. 1 is an overall configuration diagram of a reactive power compensation system according to a first embodiment of the present invention.

【図２】図１の制御装置の動作を示す電圧変動抽出特性
の説明図。FIG. 2 is an explanatory diagram of a voltage fluctuation extraction characteristic showing an operation of the control device of FIG. 1;

【図３】図１の無効電力補償装置の補償動作の説明図。FIG. 3 is an explanatory diagram of a compensation operation of the reactive power compensation device of FIG. 1;

【図４】図１無効電力補償システムの補償分担過程を示
す説明図。FIG. 4 is an explanatory diagram showing a compensation sharing process of the reactive power compensation system of FIG. 1;

【図５】本発明の第２の実施例による無効電力補償シス
テムの全体構成図。FIG. 5 is an overall configuration diagram of a reactive power compensation system according to a second embodiment of the present invention.

【図６】本発明の第３の実施例による無効電力補償シス
テムの全体構成図。FIG. 6 is an overall configuration diagram of a reactive power compensation system according to a third embodiment of the present invention.

【図７】図６の不感帯回路の入出力特性を示す説明図。FIG. 7 is an explanatory diagram showing input / output characteristics of the dead band circuit of FIG. 6;

【図８】本発明の第４の実施例による無効電力補償シス
テムの全体構成図。FIG. 8 is an overall configuration diagram of a reactive power compensation system according to a fourth embodiment of the present invention.

【図９】配電線の電圧変動の状況を示す説明図。FIG. 9 is an explanatory diagram showing a state of voltage fluctuation of a distribution line.

【図１０】従来の無効電力補償システムの補償動作を示
す説明図。FIG. 10 is an explanatory diagram showing a compensation operation of a conventional reactive power compensation system.

【符号の説明】[Explanation of symbols]

１…配電変電所トランス、２…配電線、３…無効電力補
償装置、４…電圧調整器、５…負荷、６…電圧変動発生
負荷、７…無効電力補償システムの制御装置、８…電圧
センサ、９…電圧検出回路、１０…特定電圧変動検出回
路、１１…補償ゲイン回路、１２…電流制御回路、１３
…PWM制御回路、１４…瞬時変動抽出回路、１５…抽出
ゲイン回路、１６…中間周波変動抽出回路、１７…抽出
ゲイン回路、１８…加算器、１９…高域通過フィルタ、
２０…低域通過フィルタ、２１…高域通過フィルタ、２
２…階段状周波数特性フィルタ、２３…不感帯回路、２
４…電流センサ、２５…系統電圧変動推定回路、２６…
系統電圧変動分析回路、２７…制御設定値演算回路、２
８…時刻情報出力回路、２９…配電線電圧変動データベ
ース、３０…外部出力回路。DESCRIPTION OF SYMBOLS 1 ... Distribution substation transformer, 2 ... Distribution line, 3 ... Reactive power compensator, 4 ... Voltage regulator, 5 ... Load, 6 ... Voltage fluctuation generating load, 7 ... Reactive power compensation system controller, 8 ... Voltage sensor .. 9 voltage detection circuit 10 specific voltage fluctuation detection circuit 11 compensation gain circuit 12 current control circuit 13
... PWM control circuit, 14 ... instantaneous fluctuation extraction circuit, 15 ... extraction gain circuit, 16 ... intermediate frequency fluctuation extraction circuit, 17 ... extraction gain circuit, 18 ... adder, 19 ... high-pass filter,
20: low-pass filter, 21: high-pass filter, 2
2: Step-like frequency characteristic filter, 23: dead zone circuit, 2
4 ... Current sensor, 25 ... System voltage fluctuation estimation circuit, 26 ...
System voltage fluctuation analysis circuit, 27... Control set value calculation circuit, 2
8: Time information output circuit, 29: Distribution line voltage fluctuation database, 30: External output circuit.

フロントページの続き (72)発明者 吉川 敏文 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 (72)発明者 相澤 英俊 茨城県日立市国分町一丁目１番１号 株式 会社日立製作所国分事業所内 (72)発明者 安孫子 堅二 宮城県仙台市青葉区一番町三丁目７番１号 東北電力株式会社内 (72)発明者 高杉 和郎 宮城県仙台市青葉区一番町三丁目７番１号 東北電力株式会社内 (72)発明者 平井 義浩 宮城県多賀城市宮内二丁目２番１号 東北 電機製造株式会社内 (72)発明者 日山 泰之 宮城県多賀城市宮内二丁目２番１号 東北 電機製造株式会社内 Ｆターム(参考） 5G066 DA01 DA04 DA08 FA01 FB11 FC04 FC14 5H420 BB13 BB16 CC04 DD03 EA30 EB09 FF03 FF04 FF26 Continued on the front page (72) Inventor Toshifumi Yoshikawa 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Hidetoshi Aizawa 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture (72) Inventor Kenji Abiko 3-7-1 Ichibancho, Aoba-ku, Sendai City, Miyagi Prefecture Tohoku Electric Power Co., Inc. (72) Inventor Kazuo Takasugi Ichibancho, Aoba-ku, Sendai City, Miyagi Prefecture 3-7-1, Tohoku Electric Power Co., Inc. (72) Inventor Yoshihiro Hirai 2-2-1, Miyauchi, Tagajo-shi, Miyagi Tohoku Electric Manufacturing Co., Ltd. (72) Inventor Yasuyuki Hiyama 2-chome, Miyauchi, Tagajo, Miyagi No. 2 1 Tohoku Electric Manufacturing Co., Ltd. F term (reference) 5G066 DA01 DA04 DA08 FA01 FB11 FC04 FC14 5H420 BB13 BB16 CC04 DD03 EA30 EB09 FF03 FF04 FF26

Claims (8)

【特許請求の範囲】[Claims] 【請求項１】 変動周期の長い常時電圧変動を補償する
電圧調整装置及び変動周期の短い瞬時電圧変動を補償す
る無効電力補償装置を接続し、この両装置により系統電
圧の補償分担が行われる電力系統に対し、系統電圧に応
じた無効電力補償量（または、無効電流補償量）を求め
て前記無効電力補償装置を制御する制御装置を備えた無
効電力補償システムにおいて、 前記制御装置は、検出した系統電圧から前記瞬時電圧変
動の瞬時成分と、前記瞬時電圧変動と前記常時電圧変動
の中間周波領域にある中間成分とを抽出する電圧変動成
分抽出手段を設け、抽出した両成分に基づいて前記無効
電力補償量を算出することを特徴とする無効電力補償シ
ステム。1. A power regulating device for compensating for a constant voltage fluctuation having a long fluctuation period and a reactive power compensating device for compensating for an instantaneous voltage fluctuation having a short fluctuation period. For a system, a reactive power compensation system including a controller that controls the reactive power compensator by obtaining a reactive power compensation amount (or a reactive current compensation amount) according to a system voltage, wherein the control device detects Voltage fluctuation component extraction means for extracting an instantaneous component of the instantaneous voltage fluctuation from the system voltage and an intermediate component in the intermediate frequency region of the instantaneous voltage fluctuation and the constant voltage fluctuation is provided, and the invalidation is performed based on both extracted components. A reactive power compensation system, which calculates a power compensation amount. 【請求項２】 請求項１において、 前記電圧変動成分抽出手段は、前記瞬時成分以上を通過
させる第１のフィルタと、前記中間成分を通過させる第
２のフィルタと、前記第１のフィルタの出力に第１のゲ
インを乗じ、前記第２のフィルタの出力に前記第１のゲ
インより小さい第２のゲインを乗じ、それぞれの乗算結
果を加算する演算回路を設けてなることを特徴とする無
効電力補償システム。2. The output of the first filter according to claim 1, wherein the voltage fluctuation component extraction means includes a first filter that passes the instantaneous component or more, a second filter that passes the intermediate component, and an output of the first filter. And a first gain, multiplying the output of the second filter by a second gain smaller than the first gain, and adding an operation result of the respective multiplications. Compensation system. 【請求項３】 変動周期の長い常時電圧変動を補償する
電圧調整装置及び変動周期の短い瞬時電圧変動を補償す
る無効電力補償装置を接続して、この両装置により系統
電圧の補償分担が行われる電力系統に対し、系統電圧に
応じた無効電力補償量を求めて前記無効電力補償装置を
制御する制御装置を備えた無効電力補償システムにおい
て、 前記制御装置は、検出した系統電圧から前記瞬時電圧変
動の瞬時成分と、前記瞬時電圧変動より変動周期の長い
中間周波成分を抽出する電圧変動成分抽出手段を設け、
前記瞬時成分を補償後の前記中間周波成分の電圧補償分
担が前記電圧調整装置の補償動作と協調するように、前
記電圧変動成分抽出手段の制御定数を設定してなること
を特徴とする無効電力補償システム。3. A voltage regulating device for compensating for a constant voltage fluctuation having a long fluctuation period and a reactive power compensating device for compensating for an instantaneous voltage fluctuation having a short fluctuation period are connected. For a power system, a reactive power compensation system including a control device for controlling the reactive power compensation device by obtaining a reactive power compensation amount according to a system voltage, wherein the control device is configured to detect the instantaneous voltage fluctuation from a detected system voltage. Instantaneous component, and a voltage fluctuation component extracting means for extracting an intermediate frequency component having a fluctuation cycle longer than the instantaneous voltage fluctuation is provided,
Reactive power, wherein a control constant of the voltage fluctuation component extraction means is set such that a voltage compensation share of the intermediate frequency component after compensating the instantaneous component cooperates with a compensation operation of the voltage regulator. Compensation system. 【請求項４】 請求項３において、 前記変動成分抽出手段は、前記瞬時成分以上を通過する
持つ第１のフィルタと、前記中間周波成分を通過する第
２のフィルタと、前記第１のフィルタの出力に第１のゲ
インを乗じ、前記第２のフィルタの出力に前記第１のゲ
インより小さい第２のゲインを乗じ、両乗算の結果を加
算する演算回路を設けてなることを特徴とする無効電力
補償システム。4. The apparatus according to claim 3, wherein the variation component extracting means includes a first filter having a frequency of the instantaneous component or more, a second filter having a frequency of the intermediate frequency component, An invalidation circuit comprising an arithmetic circuit for multiplying an output by a first gain, multiplying an output of the second filter by a second gain smaller than the first gain, and adding a result of both multiplications. Power compensation system. 【請求項５】 請求項４において、 前記第１のフィルタのカットオフ周波数（または、時定
数の逆数）は系統電圧が許容限度以下に低下しない範囲
で大きく、かつ、前記第２のゲインは系統電圧が前記電
圧調整器の不感帯下限を僅かに下回る値に保持されるよ
うに、それぞれ設定してなることを特徴とする無効電力
補償システム。5. The system according to claim 4, wherein a cut-off frequency (or a reciprocal of a time constant) of the first filter is large as long as a system voltage does not drop below an allowable limit, and the second gain is a system voltage. A reactive power compensation system, wherein each voltage is set so as to be maintained at a value slightly lower than a lower limit of a dead zone of the voltage regulator. 【請求項６】 請求項１〜５のいずれかにおいて、 前記制御装置は、前記電圧変動成分抽出手段の出力を入
力とし、所定不感帯幅を持つ不感帯回路を設けてなるこ
とを特徴とする無効電力補償システム。6. The reactive power according to claim 1, wherein the control device receives an output of the voltage fluctuation component extracting unit as an input, and includes a dead band circuit having a predetermined dead band width. Compensation system. 【請求項７】 請求項６において、 前記所定不感帯幅は、前記電圧調整装置の１回のタップ
補償電圧を僅かに上回る値としてなる無効電力補償シス
テム。7. The reactive power compensation system according to claim 6, wherein the predetermined dead zone width is a value slightly larger than one tap compensation voltage of the voltage regulator. 【請求項８】 請求項１〜７のいずれかにおいて、 前記制御装置は、系統電圧の検出値と前記無効電力補償
装置の出力電流の検出値とを用いて系統に生じた電圧変
動を推定し、前記電圧変動成分抽出手段の制御定数を変
更する手段を設けたことを特徴とする無効電力補償シス
テム。8. The control device according to claim 1, wherein the control device estimates a voltage fluctuation occurring in the system using a detected value of a system voltage and a detected value of an output current of the reactive power compensator. And a means for changing the control constant of the voltage fluctuation component extracting means.