JP3820385B2 - Isolated system stabilization method and isolated system stabilization system - Google Patents

Description

【００１１】
また、上記再投入負荷量は、下記式（５）で算出した負荷量を上回り、かつ最小量となる負荷量とするものである。
【数４】

【００１２】
また、電力系統における分離系統の系統分離の発生にともない、該分離系統内の発電機の発電供給量または負荷の負荷量、または無効電力供給による調相設備の調相制御量を系統安定化装置で制御して上記分離系統を安定化する単独分離系統安定化方法において、
上記系統分離発生後のオンラインデータを用いて分離系統内の負荷の電圧静特性、脱落量を推定し、該推定した負荷の電圧静特性及び脱落量と上記分離系統における系統分離発生前の情報とに基づき、系統分離した分離系統に対して周波数偏差を考慮した潮流計算を実施する第１ステップ、
上記第１ステップにおいて実施した潮流計算の結果、分離系統内の周波数が許容値内に収まっているか否かを判断する第２ステップ、
上記第２ステップにおいて、潮流計算の結果の分離系統内の周波数が許容値内に収まっていない場合は、予め想定した負荷遮断パターン（遮断する負荷の組合せ）を優先順位にしたがって実施したと仮定して、潮流計算を実施して、負荷遮断パターンを選択する第３ステップ、
上記第２ステップにおいて、潮流計算の結果の分離系統内の周波数が許容値内に収まっている場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第４ステップ、
上記第３ステップで選択した負荷遮断を、主制御で実施する第５ステップ、
上記第５ステップにおける主制御の後、一定時間経過後の分離系統内の周波数を計測する第６ステップ、
上記第６ステップで計測した分離系統内の周波数が許容値内に収まっているか否かを判断する第７ステップ、
上記第７ステップにおいて、計測した分離系統内の周波数が許容値内に収まっていない場合は、第６ステップで遮断した負荷（フィーダー線）に対して他の負荷との組合せを想定して潮流計算を実施し、故障前周波数に最も近くなる再投入負荷の組合せを選択する第８ステップ、
上記第５ステップで遮断した負荷を、補正制御で上記第８ステップにおいて選択した再投入負荷の組合せを再投入する第９ステップ、
上記第７ステップにおいて、計測した分離系統内の周波数が許容値内に収まっている場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第１０ステップ、
を備えたものである。
【００１３】
本発明に係る単独分離系統安定化システムは、電力系統における分離系統の系統分離の発生にともない、該分離系統内の発電機の発電供給量または負荷の負荷量を系統安定化装置で制御して上記分離系統を安定化する単独分離系統安定化システムにおいて、
上記分離系統における系統分離前の情報に基づき、系統分離した分離系統の必要制御量を算出する第１手段、
上記系統分離した分離系統に対して制御が必要か否かを判断する第２手段、
上記第２手段において、分離系統に対して制御が必要と判断した場合は、上記第１手段で算出した必要制御量にしたがって、上記負荷及び発電機の一部または全部を遮断する主制御を実施する第３手段、
上記第２手段において、分離系統に対して制御が必要でないと判断した場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第４手段、
上記第３手段における主制御の後、一定時間経過後の分離系統内の周波数を計測する第５手段、
上記第５手段で計測した分離系統内の周波数が許容値内に収まっているか否かを判断する第６手段、
上記第６手段において、計測した分離系統内の周波数が許容値内に収まっていない場合は、上記計測した分離系統内の周波数に基づき再投入負荷量を算出し、上記第３手段で遮断した負荷について、上記算出した再投入負荷量を補正制御で再投入する第７手段、
上記第６手段において、計測した分離系統内の周波数が許容値内に収まっている場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第８手段、
を備えたものである。
【００１４】
また、電力系統における分離系統の系統分離の発生にともない、該分離系統内の発電機の発電供給量または負荷の負荷量、または無効電力供給による調相設備の調相制御量を系統安定化装置で制御して上記分離系統を安定化する単独分離系統安定化システムにおいて、
上記系統分離発生後のオンラインデータを用いて分離系統内の負荷の電圧静特性、脱落量を推定し、該推定した負荷の電圧静特性及び脱落量と上記分離系統における系統分離発生前の情報とに基づき、系統分離した分離系統に対して周波数偏差を考慮した潮流計算を実施する第１手段、
上記第１手段において実施した潮流計算の結果、分離系統内の周波数が許容値内に収まっているか否かを判断する第２手段、
上記第２手段において、潮流計算の結果の分離系統内の周波数が許容値内に収まっていないと判断した場合は、予め想定した負荷遮断パターン（遮断する負荷の組合せ）を優先順位にしたがって実施したと仮定して、潮流計算を実施して、負荷遮断パターンを選択する第３手段、
上記第２手段において、潮流計算の結果の分離系統内の周波数が許容値内に収まっていると判断した場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第４手段、
上記第３手段で選択した負荷遮断を、主制御で実施する第５手段、
上記第５手段における主制御の後、一定時間経過後の分離系統内の周波数を計測する第６手段、
上記第６手段で計測した分離系統内の周波数が許容値内に収まっているか否かを判断する第７手段、
上記第７手段において、計測した分離系統内の周波数が許容値内に収まっていないと判断した場合は、第６手段で遮断した負荷（フィーダー線）に対して他の負荷との組合せを想定して潮流計算を実施し、故障前周波数に最も近くなる再投入負荷の組合せを選択する第８手段、
上記第５手段で遮断した負荷を、補正制御で上記第８手段において選択した再投入負荷の組合せを再投入する第９手段、
上記第７手段において、計測した分離系統内の周波数が許容値内に収まっていると判断した場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第１０手段、
を備えたものである。
【００１５】
【発明の実施の形態】
以下に、本発明の実施の形態を説明する。
実施の形態１．
図１は、本発明に係る分離系統安定化システムの実施の形態１を示す構成図である。
【００１６】
図において、１Ａは主系統側母線、１Ｂは負荷母線、１Ｃは発電機母線、２Ａ、２Ｂは分離系統内の送電線、３Ａ〜３Ｈは遮断器、４Ａ〜４Ｇは送電線電流を取り込むためのセンサ（変流器）、５Ａ、５Ｂは母線電圧を取り込むためのセンサ（変成器）、６Ａ〜６Ｇは遮断器情報や電流・電圧を取り込むための入力ケーブル、７Ａ〜７Ｃは電源制限（電源遮断）、負荷制限（負荷遮断）及び調相制御の指令信号を出すための出力ケーブル、８Ａ〜８Ｃは分離系統内の負荷、９Ａ〜９Ｃは分離系統内の発電機、１０は送電線２Ａや母線１Ａ、１Ｂの分離故障によって分離系統が主系統側から分離された場合に、発電機９Ａ〜９Ｃまたは負荷８Ａ〜８Ｃを遮断することによって、分離系統内の周波数及び電圧を維持するための系統安定化装置である。
【００１７】
上記図１の構成において、例えば、送電線２Ａでルート断に至る故障が発生し、単独分離系統が発生した場合（母線１Ａと母線１Ｂとの接続が分断された場合）、系統安定化装置１０は、遮断器３Ａまたは遮断器３Ｂの遮断情報を入力ケーブル６Ａ、６Ｂを通して取り込むことによって、単独分離系統が発生したことを認識して、安定化制御（負荷制限、電源制限）を実施する。
【００１８】
図２は、系統安定化装置１０において実行される安定化制御の制御論理フローチャートである。同図に従って安定化制御の方法を説明する。
【００１９】
ステップＳＴ１：分離系統における系統分離発生前（事前）において、入力ケーブル６Ｃ〜６Ｇから得られる分離系統内の母線電圧、負荷量、発電機出力及び連系線潮流等のデータを収集する。
【００２０】
ステップＳＴ２：ステップＳＴ１で収集したデータを基に系統分離発生時の必要制御量を算出し、予め準備された制御量テーブルを更新する。
【００２１】
ステップＳＴ３：送電線２Ａがルート断となり、単独分離系統となったことを認識する。
【００２２】
ステップＳＴ４：ステップＳＴ２で更新した最新の制御量テーブルを参照し、単独分離系統の必要制御量を算出する。
【００２３】
ステップＳＴ５：単独分離系統に対して制御が必要か否かを判断し、制御が必要な場合はステップＳＴ６に進み、その他の場合はステップＳＴ１０に進む。
【００２４】
ステップＳＴ６：ステップＳＴ４で算出した制御量にしたがって、系統安定化装置１０は、出力ケーブル７Ａまたは７Ｂを通して負荷８Ａ〜８Ｃまたは発電機９Ａ〜９Ｃの一部または全部を遮断する指令を出力し、制御（主制御）を実施する。
【００２５】
ステップＳＴ７：ステップ６の主制御の後、一定時間経過後の分離系統内の周波数を計測する。
【００２６】
ステップＳＴ８：ステップＳＴ７で計測した分離系統内の周波数が許容値内に収まっているか否かを判断し、許容値内に収まっている場合はステップＳＴ１０に進み、その他の場合はステップＳＴ９に進む。
【００２７】
ステップＳＴ９：ステップＳＴ７で計測した周波数に基づき、再投入量を算出し、系統安定化装置１０は出力ケーブル７Ａを通して負荷８Ａ〜８Ｃに指令を出力し、遮断した負荷を、算出した再投入量にしたがって再投入する補正制御を実施する。
【００２８】
ステップＳＴ１０：全ての分離系統処理が完了したと判断して、系統安定化装置１０を定常状態に戻す。
【００２９】
本実施の形態においては、主制御後の収束周波数が許容値より上昇した場合に、主制御において遮断した負荷の一部または全部を再投入する補正制御を実施することによって、収束周波数を許容値内まで低下させるようにしたので、新たな発電機遮断による遮断量の増加を防ぎ、制御量を極小化することができるとともに、質の高い電力供給ができる。
【００３０】
なお、本実施の形態に係る単独分離系統安定化システムは、上記ステップＳＴ１ないしステップＳＴ１２を実行する手段を系統安定化装置１０が備えているものである。また、上記各ステップの実行手段を系統安定化装置１０と連係させて備えた構成としてもよい。
【００３１】
実施の形態２．
本実施の形態は、上記実施の形態１の補正制御における、再投入負荷量の算出方法に関するものである。
【００３２】
図３は、本実施の形態における安定化制御の制御論理フローチャートであり、同図に従って安定化制御の方法を説明する。
【００３３】
例えば、図１を参照し、送電線２Ａでルート断に至る故障が発生し、単独分離系統が発生（母線１Ａと母線１Ｂが分断されることを意味する。）した場合には、遮断器３Ａまたは遮断器３Ｂの遮断情報を入力ケーブル６Ａ、６Ｂを通して取り込むことにより、系統安定化装置１０は単独分離系統発生を認識し、以下のステップによって安定化処理を実施する。
【００３４】
ステップＳＴ１：系統分離発生前における、入力ケーブル６Ｃ〜６Ｇから得られる系統情報、母線電圧、負荷量、発電機出力及び連系線潮流等のデータを収集する。
【００３５】
ステップＳＴ２：ステップＳＴ１で収集したデータを基に系統分離発生時の必要制御量を算出し、予め準備された制御量テーブルを更新する。
【００３６】
ステップＳＴ３：送電線２Ａがルート断となり、単独分離系統となったことを認識する。
【００３７】
ステップＳＴ４：ステップＳＴ２で更新した最新の制御量テーブルを参照し、単独分離系統の必要制御量を算出する。
【００３８】
ステップＳＴ５：単独分離系統に対して制御が必要か否かを判断し、制御が必要な場合はステップＳＴ６に進み、その他の場合はステップＳＴ１３に進む。
【００３９】
ステップＳＴ６：ステップＳＴ４で算出した制御量にしたがって、系統安定化装置１０は、出力ケーブル７Ａまたは７Ｂを通して負荷８Ａ〜８Ｃまたは発電機９Ａ〜９Ｃの一部または全部を遮断する指令を出力し、制御（主制御）を実施する。
【００４０】
ステップＳＴ７：ステップ６の主制御の後、一定時間経過後の分離系統内の周波数を計測する。
【００４１】
ステップＳＴ８：ステップＳＴ７で計測した分離系統内の周波数が許容値内に収まっているか否かを判断し、許容値内に収まっている場合はステップＳＴ１３に進み、その他の場合はステップＳＴ９に進む。
【００４２】
ステップＳＴ９：この時点（ステップＳＴ７で一定時間経過後の分離系統内の周波数を計測した時点）での分離系統内の発電量、負荷量及び収束周波数より、需給バランスの式である下記式（１）を立てる。なお、分離系統内の負荷の系統定数ＫＬは、オンライン推定方式またはオフライン推定方式によって別途求めておき、分離系統内の電源の系統定数は、予め設定しておく。
【００４３】
【数５】

【００４４】
ステップＳＴ１０：上記式（１）を基にして、下記式（２）を立て、この式（２）を変形して得られる下記式（３）にしたがって、再投入負荷量ＰＬＴを算出する。
【００４５】
【数６】

【数７】

【００４６】
ステップＳＴ１１：ステップＳＴ１０で算出した負荷量を上回り、かつ最小量となる負荷８Ａ〜８Ｃの組合せを選択する。
【００４７】
ステップＳＴ１２：系統安定化装置１０は出力ケーブル７Ａを通して負荷８Ａ〜８Ｃに指令を出力し、ステップＳＴ１１で選択した負荷の組合せを再投入する補正制御を実施する。
【００４８】
ステップＳＴ１３：全ての分離系統処理が完了したと判断して、系統安定化装置１０を定常状態に戻す。
【００４９】
以上のようにして、具体的な負荷再投入量を、簡単な式で算出することができ、計算の負荷を軽減することができる。
【００５０】
なお、本実施の形態に係る単独分離系統安定化システムは、上記ステップＳＴ１ないしステップＳＴ１３を実行する手段を系統安定化装置１０が備えているものである。また、上記各ステップの実行手段を系統安定化装置１０と連係させて備えた構成としてもよい。
【００５１】
実施の形態３．
遮断により分離系統に系統分離が発生した場合、再投入した負荷（フィーダー線）が全て遮断前の負荷量を保持しているとは限らない。例えば、遮断のショックによって負荷そのものが脱落している場合も想定される。
【００５２】
本実施の形態は、再投入した負荷の復帰量を求める方法に関するものである。
【００５３】
図４は、本実施の形態における安定化制御の制御論理フローチャートであり、同図に従って安定化制御の方法を説明する。
【００５４】
例えば、図１を参照し、送電線２Ａでルート断に至る故障が発生し、単独分離系統が発生（母線１Ａと母線１Ｂが分断されることを意味する。）した場合には、遮断器３Ａまたは遮断器３Ｂの遮断情報を入力ケーブル６Ａ、６Ｂを通して取り込むことにより、系統安定化装置１０は単独分離系統発生を認識し、以下のステップによって安定化処理を実施する。
【００５５】
ステップＳＴ１：系統分離発生前における、入力ケーブル６Ｃ〜６Ｇから得られる系統情報、母線電圧、負荷量、発電機出力及び連系線潮流等のデータを収集する。
【００５６】
ステップＳＴ２：ステップＳＴ１で収集したデータを基に系統分離発生時の必要制御量を算出し、予め準備された制御量テーブルを更新する。
【００５７】
ステップＳＴ３：送電線２Ａがルート断となり、単独分離系統となったことを認識する。
【００５８】
ステップＳＴ４：センサ５Ａで計測される故障直後の負荷母線電圧値を入力ケーブル６Ｄを通して系統安定化装置１０は取り込み、負荷の復帰率（％）と電圧低下値との関係を示す図５と照合して、遮断した負荷の復帰率を保持しておく。なお、図５はシミュレーション等によって、予め設定しておくものとする。
【００５９】
ステップＳＴ５：ステップＳＴ２で更新した最新の制御量テーブルを参照し、単独分離系統の必要制御量を算出する。
【００６０】
ステップＳＴ６：単独分離系統に対して制御が必要か否かを判断し、制御が必要な場合はステップＳＴ７に進み、その他の場合はステップＳＴ１４に進む。
【００６１】
ステップＳＴ７：ステップＳＴ５で算出した制御量にしたがって、系統安定化装置１０は、出力ケーブル７Ａまたは７Ｂを通して負荷８Ａ〜８Ｃまたは発電機９Ａ〜９Ｃの一部または全部を遮断する指令を出力し、制御（主制御）を実施する。
【００６２】
ステップＳＴ８：ステップ６の主制御の後、一定時間経過後の分離系統内の周波数を計測する。
【００６３】
ステップＳＴ９：ステップＳＴ８で計測した分離系統内の周波数が許容値内に収まっているか否かを判断し、許容値内に収まっている場合はステップＳＴ１４に進み、その他の場合はステップＳＴ１０に進む。
【００６４】
ステップＳＴ１０：この時点（ステップＳＴ８で一定時間経過後の分離系統内の周波数を計測した時点）での分離系統内の発電量、負荷量及び収束周波数より、需給バランスの式である上記式（１）（実施の形態２参照）を立てる。なお、分離系統内の負荷の系統定数ＫＬは、オンライン推定方式またはオフライン推定方式によって別途求めておき、分離系統内の電源の系統定数は、予め設定しておく。
【００６５】
ステップＳＴ１１：上記式（１）を基にして、下記式（４）を立て、この式（４）を変形して得られる下記式（５）にしたがって、再投入負荷量ＰＬＴを算出する。
【００６６】
【数８】

【数９】

【００６７】
ステップＳＴ１２：ステップＳＴ７で実施した主制御において負荷遮断を実施した場合に、ステップＳＴ１１で算出した負荷量を上回り、かつ最小量となる負荷８Ａ〜８Ｃの組合せを選択する。
【００６８】
ステップＳＴ１３：系統安定化装置１０は出力ケーブル７Ａを通して負荷８Ａ〜８Ｃに指令を出力し、ステップＳＴ１２で選択した負荷を再投入する補正制御を実施する。
【００６９】
ステップＳＴ１４：全ての分離系統処理が完了したと判断して、系統安定化装置１０を定常状態に戻す。
【００７０】
以上のように、負荷遮断等によって負荷脱落が生じたような場合に、それら負荷について、再投入する負荷（フィーダー線）の復帰率を考慮できるようにしたので、より質の高い電力供給ができる。
【００７１】
なお、本実施の形態に係る単独分離系統安定化システムは、上記ステップＳＴ１ないしステップＳＴ１４を実行する手段を系統安定化装置１０が備えているものである。また、上記各ステップの実行手段を系統安定化装置１０と連係させて備えた構成としてもよい。
【００７２】
実施の形態４．
本実施の形態は、再投入負荷量の算出に潮流計算を用いる方法に関するものである。
【００７３】
図６は、本発明に係る分離系統安定化システムの実施の形態１を示す構成図であり、図１と同一符号は同一部分または相当部分を示す。同図において、１１は負荷母線１Ｂへの無効電力の供給または負荷母線１Ｂから無効電力をしょうひすることによって、負荷母線１Ｂの電圧を調整する調相設備、１２は中央給電指令所、１３Ａは中央給電指令所１２から系統安定化装置１０に系統情報を伝達する通信路、１３Ｂは調相設備１１の調相投入量を系統安定化装置１０に伝達する通信路である。
【００７４】
図７は、本実施の形態における安定化制御の制御論理フローチャートであり、同図に従って安定化制御の方法を説明する。
【００７５】
例えば、図６において、送電線２Ａでルート断に至る故障が発生し、単独分離系統が発生（母線１Ａと母線１Ｂが分断されることを意味する。）した場合には、遮断器３Ａまたは遮断器３Ｂの遮断情報を入力ケーブル６Ａ、６Ｂを通して取り込むことにより、系統安定化装置１０は単独分離系統発生を認識し、以下のステップによって安定化処理を実施する。
【００７６】
ステップＳＴ１：系統分離発生前における、入力ケーブル６Ｃ〜６Ｇ及び通信路１３Ｂから得られる系統情報及び分離系統内の母線電圧、負荷量、発電機出力、連系線潮流及び調相投入量、並びに伝送路１３Ａを通して得られる中央給電指令所１２からの情報（例えば、系統容量等）等から、潮流計算用のデータを収集する。
【００７７】
ステップＳＴ２：送電線２Ａがルート断となったことを認識する。
【００７８】
ステップＳＴ３：系統分離発生後のオンラインデータを用いて分離系統内の負荷の電圧静特性及び脱落量を推定する。
【００７９】
ステップＳＴ４：ステップＳＴ１で収集したデータとステップＳＴ３で推定した負荷の電圧静特性及び脱落量を基に、分離系統に対して周波数偏差を考慮した潮流計算を実施する。
【００８０】
ステップＳＴ５：ステップＳＴ４で実施した潮流計算の結果、分離系統内の周波数が許容値内に収まっているか否かを判断し、収まっている場合はステップＳＴ１２に進み、その他の場合はステップＳＴ６に進む。
【００８１】
ステップＳＴ６：予め想定した負荷遮断パターン（遮断する負荷の組合せ）を優先順位にしたがって実施したと仮定して、潮流計算を実施して、負荷遮断パターンを選択する。なお、この際、負荷遮断パターンについては、予め他の方法によってパターン化し、優先順位も予め決定しておく。
【００８２】
ステップＳＴ７：系統安定化装置１０は、出力ケーブル７Ａ、７Ｃを通して、ステップ６で選択した負荷遮断を実施する（主制御）。
【００８３】
ステップＳＴ８：主制御実施の後、一定時間経過後の分離系統内の周波数を計測する。
【００８４】
ステップＳＴ９：ステップＳＴ８で計測した分離系統内の周波数が許容値内に収まっているか否かを判断し、許容値内に収まっている場合はステップＳＴ１２に進み、その他の場合はステップＳＴ１０に進む。
【００８５】
ステップＳＴ１０：ステップＳＴ７で遮断した負荷（フィーダー線）に対して他の負荷との組合せを想定して潮流計算を実施し、故障前周波数に最も近くなる再投入負荷の組合せを選択する。
【００８６】
ステップＳＴ１１：系統安定化装置１０は、出力ケーブル７Ａを通し、ステップ１０で選択した負荷を再投入して、分離系統内の周波数を許容値まで下げる（補正制御）。
【００８７】
ステップＳＴ１２：全ての分離系統処理が完了したと判断して、系統安定化装置１０を定常状態に戻す。
【００８８】
以上のように、本実施の形態では、潮流計算を用いて主制御で遮断した負荷を、潮流計算によって再投入量を潮流計算し、この再投入量にしたがって補正制御で再投入するようにしたので、制御量を極小化することができるとともに、質の高い電力供給ができる。
【００８９】
なお、本実施の形態に係る単独分離系統安定化システムは、上記ステップＳＴ１ないしステップＳＴ１２を実行する手段を系統安定化装置１０が備えているものである。また、上記各ステップの実行手段を系統安定化装置１０と連係させて備えた構成としてもよい。
【００９０】
【発明の効果】
本発明に係る単独分離系統安定化方法によれば、電力系統における分離系統の系統分離の発生にともない、該分離系統内の発電機の発電供給量または負荷の負荷量を系統安定化装置で制御して上記分離系統を安定化する単独分離系統安定化方法において、
上記分離系統における系統分離前の情報に基づき、系統分離した分離系統の必要制御量を算出する第１ステップ、
上記系統分離した分離系統に対して制御が必要か否かを判断する第２ステップ、
上記第２ステップにおいて、分離系統に対して制御が必要と判断した場合は、上記第１ステップで算出した必要制御量にしたがって、上記負荷及び発電機の一部または全部を遮断する主制御を実施する第３ステップ、
上記第２ステップにおいて、分離系統に対して制御が必要でないと判断した場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第４ステップ、
上記第３ステップにおける主制御の後、一定時間経過後の分離系統内の周波数を計測する第５ステップ、
上記第５ステップで計測した分離系統内の周波数が許容値内に収まっているか否かを判断する第６ステップ、
上記第６ステップにおいて、計測した分離系統内の周波数が許容値内に収まっていない場合は、上記計測した分離系統内の周波数に基づき再投入負荷量を算出し、上記第３ステップで遮断した負荷について、上記算出した再投入負荷量を補正制御で再投入する第７ステップ、
上記第６ステップにおいて、計測した分離系統内の周波数が許容値内に収まっている場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第８ステップ、
を備えたものであるので、新たな発電機遮断を実施する必要がなく、制御量を極小化することができ、質の高い電力供給ができる。
【００９１】
また、上記再投入負荷量は、下記式（３）で算出した負荷量を上回り、かつ最小量となる負荷量とするものであるので、簡単な式で負荷再投入量の算出ができ、計算に対する負荷が軽減できる。
【数１０】

【００９２】
また、上記再投入負荷量は、下記式（５）で算出した負荷量を上回り、かつ最小量となる負荷量とするものであるので、負荷遮断等のショックにより負荷脱落が生じた場合にも、その負荷脱落を考慮することができ、より質の高い電力供給ができる。
【数１１】

【００９３】
また、電力系統における分離系統の系統分離の発生にともない、該分離系統内の発電機の発電供給量または負荷の負荷量、または無効電力供給による調相設備の調相制御量を系統安定化装置で制御して上記分離系統を安定化する単独分離系統安定化方法において、
上記系統分離発生後のオンラインデータを用いて分離系統内の負荷の電圧静特性、脱落量を推定し、該推定した負荷の電圧静特性及び脱落量と上記分離系統における系統分離発生前の情報とに基づき、系統分離した分離系統に対して周波数偏差を考慮した潮流計算を実施する第１ステップ、
上記第１ステップにおいて実施した潮流計算の結果、分離系統内の周波数が許容値内に収まっているか否かを判断する第２ステップ、
上記第２ステップにおいて、潮流計算の結果の分離系統内の周波数が許容値内に収まっていない場合は、予め想定した負荷遮断パターン（遮断する負荷の組合せ）を優先順位にしたがって実施したと仮定して、潮流計算を実施して、負荷遮断パターンを選択する第３ステップ、
上記第２ステップにおいて、潮流計算の結果の分離系統内の周波数が許容値内に収まっている場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第４ステップ、
上記第３ステップで選択した負荷遮断を、主制御で実施する第５ステップ、
上記第５ステップにおける主制御の後、一定時間経過後の分離系統内の周波数を計測する第６ステップ、
上記第６ステップで計測した分離系統内の周波数が許容値内に収まっているか否かを判断する第７ステップ、
上記第７ステップにおいて、計測した分離系統内の周波数が許容値内に収まっていない場合は、第６ステップで遮断した負荷（フィーダー線）に対して他の負荷との組合せを想定して潮流計算を実施し、故障前周波数に最も近くなる再投入負荷の組合せを選択する第８ステップ、
上記第５ステップで遮断した負荷を、補正制御で上記第８ステップにおいて選択した再投入負荷の組合せを再投入する第９ステップ、
上記第７ステップにおいて、計測した分離系統内の周波数が許容値内に収まっている場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第１０ステップ、
を備えたものであるので、制御量を極小化することができ、より質の高い電力供給が可能になる。
【００９４】
本発明に係る単独分離系統安定化システムによれば、電力系統における分離系統の系統分離の発生にともない、該分離系統内の発電機の発電供給量または負荷の負荷量を系統安定化装置で制御して上記分離系統を安定化する単独分離系統安定化システムにおいて、
上記分離系統における系統分離前の情報に基づき、系統分離した分離系統の必要制御量を算出する第１手段、
上記系統分離した分離系統に対して制御が必要か否かを判断する第２手段、
上記第２手段において、分離系統に対して制御が必要と判断した場合は、上記第１手段で算出した必要制御量にしたがって、上記負荷及び発電機の一部または全部を遮断する主制御を実施する第３手段、
上記第２手段において、分離系統に対して制御が必要でないと判断した場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第４手段、
上記第３手段における主制御の後、一定時間経過後の分離系統内の周波数を計測する第５手段、
上記第５手段で計測した分離系統内の周波数が許容値内に収まっているか否かを判断する第６手段、
上記第６手段において、計測した分離系統内の周波数が許容値内に収まっていない場合は、上記計測した分離系統内の周波数に基づき再投入負荷量を算出し、上記第３手段で遮断した負荷について、上記算出した再投入負荷量を補正制御で再投入する第７手段、
上記第６手段において、計測した分離系統内の周波数が許容値内に収まっている場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第８手段、
を備えたものであるので、新たな発電機遮断を実施する必要がなく、制御量を極小化することができ、質の高い電力供給ができる。
【００９５】
また、電力系統における分離系統の系統分離の発生にともない、該分離系統内の発電機の発電供給量または負荷の負荷量、または無効電力供給による調相設備の調相制御量を系統安定化装置で制御して上記分離系統を安定化する単独分離系統安定化システムにおいて、
上記系統分離発生後のオンラインデータを用いて分離系統内の負荷の電圧静特性、脱落量を推定し、該推定した負荷の電圧静特性及び脱落量と上記分離系統における系統分離発生前の情報とに基づき、系統分離した分離系統に対して周波数偏差を考慮した潮流計算を実施する第１手段、
上記第１手段において実施した潮流計算の結果、分離系統内の周波数が許容値内に収まっているか否かを判断する第２手段、
上記第２手段において、潮流計算の結果の分離系統内の周波数が許容値内に収まっていないと判断した場合は、予め想定した負荷遮断パターン（遮断する負荷の組合せ）を優先順位にしたがって実施したと仮定して、潮流計算を実施して、負荷遮断パターンを選択する第３手段、
上記第２手段において、潮流計算の結果の分離系統内の周波数が許容値内に収まっていると判断した場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第４手段、
上記第３手段で選択した負荷遮断を、主制御で実施する第５手段、
上記第５手段における主制御の後、一定時間経過後の分離系統内の周波数を計測する第６手段、
上記第６手段で計測した分離系統内の周波数が許容値内に収まっているか否かを判断する第７手段、
上記第７手段において、計測した分離系統内の周波数が許容値内に収まっていないと判断した場合は、第６手段で遮断した負荷（フィーダー線）に対して他の負荷との組合せを想定して潮流計算を実施し、故障前周波数に最も近くなる再投入負荷の組合せを選択する第８手段、
上記第５手段で遮断した負荷を、補正制御で上記第８手段において選択した再投入負荷の組合せを再投入する第９手段、
上記第７手段において、計測した分離系統内の周波数が許容値内に収まっていると判断した場合は、全ての分離系統の処理が完了したと判断して、上記系統安定化装置を定常運転とする第１０手段、
を備えたものであるので、制御量を極小化することができ、より質の高い電力供給が可能になる。
【図面の簡単な説明】
【図１】 本発明に係る分離系統安定化システムの実施の形態１を示す構成図である。
【図２】 実施の形態１における、安定化制御の制御論理フローチャートである。
【図３】 実施の形態２における、安定化制御の制御論理フローチャートである。
【図４】 実施の形態３における、安定化制御の制御論理フローチャートである。
【図５】 実施の形態３において用いる、負荷の復帰率と電圧低下値との関係を例示する図である。
【図６】 本発明に係る分離系統安定化システムの実施の形態４を示す構成図である。
【図７】 実施の形態４における、安定化制御の制御論理フローチャートである。
【図８】 従来の分離系統安定化装置を示す構成図である。
【符号の説明】
１Ａ 主系統母線、１Ｂ 負荷母線、１Ｃ 発電機母線、
２Ａ，２Ｂ 分離系統内送電線、３Ａ〜３Ｈ 遮断器、
４Ａ〜４Ｇ センサ（変流器）、５Ａ，５Ｂ センサ（変成器）、
６Ａ〜６Ｇ 入力ケーブル、７Ａ〜７Ｃ 出力ケーブル、８Ａ〜８Ｃ 負荷、
９Ａ〜９Ｃ 発電機、１０ 系統安定化装置、１１ 調相設備、
１２ 中央給電指令所、１３Ａ，１３Ｂ 通信路。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for stabilizing a single isolated system and a single isolated system, which performs stabilization by performing power supply restriction or load restriction in order to stably operate the inside of the separated system when a single disconnection system occurs due to a route disconnection accident in the power system. The present invention relates to a separation system stabilization system.
[0002]
[Prior art]
Fig. 8 shows system stabilization based on the conventional isolated system stabilization method shown in "Frequency control in consideration of plant characteristics and verification by system simulator", IEEJ power technology research material, PE-97-186. It is a block diagram of a control apparatus.
[0003]
In the figure, 1B to 1C are buses in the separation system, 2A and 2B are power transmission lines in the separation system, 3A to 3H are circuit breakers, 4A to 4G are sensors (current transformers) for capturing transmission line current, 5A 5B is a sensor (transformer) for taking in the bus voltage, 6A to 6G are input cables for taking in the breaker information and current / voltage, and 7A to 7C are power supply restriction (power interruption) and load restriction (load interruption). Output cable for issuing command signals, 8A to 8C are loads in the separated system, 9A to 9C are generators in the separated system, and 10 is the separated system due to the separation failure of the transmission line 2A and buses 1A and 1B It is a system stabilizing device for maintaining the frequency and voltage in the separated system by cutting off the generators 9A to 9C or the loads 8A to 8C when separated from the generator.
[0004]
The system stabilizing device 10 obtains the bus voltage, load amount, generator output, linkage line power flow, and supplied phase adjustment amount from the input cables 6A to 6F in the separated system, and performs power flow calculation at regular intervals. To do.
[0005]
When the power transmission line 2A is cut off and system separation occurs in the separated system, the system stabilizing device 10 recognizes from the signals obtained through the input cables 6A and 6B that the power transmission line 2A is cut off and system separation has occurred. Based on various information of the isolated system before the occurrence of the system separation, the tidal current calculation in the isolated system (a power flow calculation that can take into account frequency fluctuations) is performed, and the frequency and voltage of the isolated system after the system separation occurs are calculated. When each value deviates from the operation allowable value, the control amount is calculated so that the operation can be performed within the allowable value, and the control commands are sent to the generators 9A to 9C and the loads 8A to 8C through the output cables 7A and 7B. Is output.
[0006]
In this conventional system stabilizing device, the necessity of control is judged from the fluctuation range of frequency and voltage and the operation allowable value. If control is necessary, either the generator or the load is shut off, and the frequency and voltage are set. Take control.
[0007]
[Problems to be solved by the invention]
When system separation occurs, in cases where the frequency decreases, load drop is predicted and load control is performed to adjust the supply and demand balance.However, the predicted load drop is larger than the actual amount, and the cutoff amount is larger than necessary. The case where it becomes. In this case, since the amount of power generation becomes excessive, the generator must be shut off newly as correction control. As a result, useless generator control is required. As a result of the control, there is a problem that load control must be performed in order to further balance supply and demand.
[0008]
The present invention solves the above problems, and can minimize the amount of generator cutoff or load cutoff necessary for maintaining a single system frequency, and further considers the load recovery rate, etc. An object of the present invention is to provide an isolated system stabilization method and an isolated system stabilization system capable of supplying high-quality electric power.
[0009]
[Means for Solving the Problems]
The method for stabilizing a single isolated system according to the present invention controls the power supply amount of a generator or the load amount of a load in the separated system with the system stabilizing device as the system separation of the separated system occurs in the power system. In the method of stabilizing a single separated system for stabilizing the separated system,
A first step of calculating a necessary control amount of the separated system separated based on the information before the system separation in the separated system;
A second step of determining whether control is necessary for the separated system separated from the system;
When it is determined in the second step that control is required for the separated system, main control is performed to shut off part or all of the load and the generator according to the necessary control amount calculated in the first step. The third step,
In the second step, when it is determined that control is not required for the separated system, it is determined that the processing of all the separated systems is completed, and the fourth step is performed so that the system stabilizing device is in steady operation.
After the main control in the third step, the fifth step of measuring the frequency in the separation system after a certain time has elapsed,
A sixth step of determining whether or not the frequency in the separated system measured in the fifth step is within an allowable value;
In the sixth step, if the measured frequency in the separated system does not fall within the allowable value, the re-input load amount is calculated based on the measured frequency in the separated system, and the load blocked in the third step A seventh step of re-charging the calculated re-loading load amount with correction control,
In the sixth step, if the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the eighth operation. Step,
It is equipped with.
[0010]
The re-input load amount is a load amount that exceeds the load amount calculated by the following equation (3) and is the minimum amount.
[Equation 3]

[0011]
The re-input load amount is a load amount that exceeds the load amount calculated by the following equation (5) and is the minimum amount.
[Expression 4]

[0012]
In addition, in accordance with the occurrence of system separation of the separated system in the power system, the power generation supply amount of the generator in the separated system or the load amount of the load, or the phase control amount of the phase adjusting equipment by the reactive power supply is controlled by the system stabilization device. In the method of stabilizing a single separated system controlled by the above and stabilizing the separated system,
Estimate the static voltage characteristics and dropout of the load in the separated system using the online data after the occurrence of the system separation, the estimated voltage static characteristics and dropout of the load, and information before the system separation in the separated system A first step of performing a power flow calculation considering a frequency deviation with respect to a separated system, based on
A second step of determining whether or not the frequency in the separation system is within an allowable value as a result of the tidal current calculation performed in the first step;
In the above second step, when the frequency in the separated system as a result of the power flow calculation is not within the allowable value, it is assumed that the assumed load breaking pattern (the combination of loads to be blocked) is executed according to the priority order. The third step of performing the load flow calculation and selecting the load shedding pattern,
In the second step, when the frequency in the separated system as a result of the power flow calculation is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the steady operation. The fourth step,
A fifth step in which the load cutoff selected in the third step is performed in the main control;
After the main control in the fifth step, a sixth step of measuring the frequency in the separation system after a certain time has elapsed,
A seventh step for determining whether or not the frequency in the separated system measured in the sixth step is within an allowable value;
In the seventh step, if the measured frequency in the separated system is not within the allowable value, the load flow calculated in the sixth step (feeder line) is assumed to be combined with other loads to calculate the power flow. And an eighth step of selecting the re-loading load combination that is closest to the pre-failure frequency,
A ninth step in which the load cut off in the fifth step is re-charged with the combination of the re-load loads selected in the eighth step in the correction control;
In the seventh step, when the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set in the steady operation. Step,
It is equipped with.
[0013]
The isolated system stabilization system according to the present invention controls the power supply amount of the generator or the load amount of the load in the separated system by the system stabilizing device with the occurrence of the system separation of the separated system in the power system. In a single separation system stabilization system for stabilizing the separation system,
A first means for calculating a necessary control amount of the separated system separated based on the information before the system separation in the separated system;
A second means for determining whether or not control is necessary for the separated system separated from the system;
In the second means, when it is determined that control is required for the separated system, main control is performed to shut off part or all of the load and the generator according to the required control amount calculated by the first means. A third means to
In the second means, if it is determined that control is not required for the separated system, it is determined that the processing of all the separated systems is completed, and fourth means for making the system stabilizing device in steady operation,
A fifth means for measuring a frequency in the separation system after a lapse of a fixed time after the main control in the third means;
Sixth means for determining whether or not the frequency in the separation system measured by the fifth means is within an allowable value;
In the sixth means, when the measured frequency in the separated system is not within the allowable value, the re-input load amount is calculated based on the measured frequency in the separated system, and the load blocked by the third means A seventh means for re-inputting the calculated re-input load amount with correction control,
In the sixth means, when the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the eighth operation. means,
It is equipped with.
[0014]
In addition, in accordance with the occurrence of system separation of the separated system in the power system, the power generation supply amount of the generator in the separated system or the load amount of the load, or the phase control amount of the phase adjusting equipment by the reactive power supply is controlled by the system stabilization device. In a single separation system stabilization system that is controlled by the above and stabilizes the separation system,
Estimate the static voltage characteristics and dropout of the load in the separated system using the online data after the occurrence of the system separation, the estimated voltage static characteristics and dropout of the load, and information before the system separation in the separated system A first means for performing a power flow calculation considering a frequency deviation with respect to a separated system separated based on
A second means for determining whether or not the frequency in the separation system is within an allowable value as a result of the tidal current calculation performed in the first means;
In the above second means, when it is determined that the frequency in the separated system as a result of the power flow calculation is not within the allowable value, a load interruption pattern (a combination of loads to be interrupted) is executed in accordance with the priority order. Assuming that, a third means for performing load flow calculation and selecting a load shedding pattern,
In the second means, when it is determined that the frequency in the separated system as a result of the power flow calculation is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is A fourth means for steady operation;
A fifth means for performing the load cutoff selected by the third means by the main control;
A sixth means for measuring a frequency in the separation system after a lapse of a fixed time after the main control in the fifth means;
A seventh means for determining whether or not the frequency in the separation system measured by the sixth means is within an allowable value;
In the seventh means, when it is determined that the measured frequency in the separated system is not within the allowable value, a combination with another load is assumed for the load (feeder line) blocked by the sixth means. The eighth means for performing the power flow calculation and selecting the combination of the re-input loads closest to the pre-failure frequency,
A ninth means for re-feeding the load cut off by the fifth means with the combination of re-load loads selected in the eighth means by correction control;
In the seventh means, when it is determined that the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the steady operation. 10th means to
It is equipped with.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing Embodiment 1 of a separation system stabilization system according to the present invention.
[0016]
In the figure, 1A is a main system side bus, 1B is a load bus, 1C is a generator bus, 2A and 2B are power transmission lines in a separate system, 3A to 3H are circuit breakers, and 4A to 4G are for capturing power transmission line currents Sensors (current transformers), 5A and 5B are sensors (transformers) for taking in the bus voltage, 6A to 6G are input cables for taking in circuit breaker information and current / voltage, and 7A to 7C are power supply restrictions (power cut-off) ), Output cable for issuing command signals for load limitation (load cutoff) and phase control, 8A to 8C are loads in the separated system, 9A to 9C are generators in the separated system, 10 is the power transmission line 2A and bus When the separated system is separated from the main system side due to the separation failure of 1A and 1B, the system stability for maintaining the frequency and voltage in the separated system by cutting off the generators 9A to 9C or the loads 8A to 8C Device .
[0017]
In the configuration of FIG. 1 described above, for example, when a failure leading to a route disconnection occurs in the transmission line 2A and a single separation system is generated (when the connection between the bus 1A and the bus 1B is disconnected), the system stabilizing device 10 Recognizes that a single separation system has occurred by taking in the breaker information of the breaker 3A or breaker 3B through the input cables 6A and 6B, and performs stabilization control (load restriction, power supply restriction).
[0018]
FIG. 2 is a control logic flowchart of the stabilization control executed in the system stabilizing device 10. A stabilization control method will be described with reference to FIG.
[0019]
Step ST1: Collect data such as bus voltage, load amount, generator output, and interconnection current in the separation system obtained from the input cables 6C to 6G before system separation occurs (in advance) in the separation system.
[0020]
Step ST2: A necessary control amount at the time of occurrence of system separation is calculated based on the data collected in step ST1, and a control amount table prepared in advance is updated.
[0021]
Step ST3: Recognize that the power transmission line 2A is disconnected and becomes a single separated system.
[0022]
Step ST4: Refer to the latest control amount table updated in step ST2, and calculate the necessary control amount of the single isolated system.
[0023]
Step ST5: It is determined whether or not control is required for the single separated system. If control is required, the process proceeds to step ST6, and otherwise the process proceeds to step ST10.
[0024]
Step ST6: According to the control amount calculated in step ST4, the system stabilizing device 10 outputs a command for cutting off a part or all of the loads 8A to 8C or the generators 9A to 9C through the output cable 7A or 7B. (Main control) is performed.
[0025]
Step ST7: After the main control in step 6, the frequency in the separation system after a certain time has elapsed is measured.
[0026]
Step ST8: It is determined whether or not the frequency in the separation system measured in step ST7 is within the allowable value. If the frequency is within the allowable value, the process proceeds to step ST10. Otherwise, the process proceeds to step ST9.
[0027]
Step ST9: Based on the frequency measured in step ST7, the recharging amount is calculated, the system stabilizing device 10 outputs a command to the loads 8A to 8C through the output cable 7A, and the interrupted load is changed to the calculated recharging amount. Therefore, the correction control to be turned on again is performed.
[0028]
Step ST10: It is determined that all the separated system processes have been completed, and the system stabilizing device 10 is returned to the steady state.
[0029]
In the present embodiment, when the convergence frequency after the main control rises above the allowable value, the convergence frequency is set to the allowable value by performing correction control for re-inserting part or all of the load cut off in the main control. Since it is lowered to the inside, it is possible to prevent an increase in the shutoff amount due to a new generator shutoff, to minimize the control amount, and to supply high-quality power.
[0030]
In addition, the isolated system stabilization system which concerns on this Embodiment is provided with the means which performs the said step ST1 thru | or step ST12 in the system stabilization apparatus 10. FIG. Moreover, it is good also as a structure provided with the execution means of each said step linked with the system | strain stabilization apparatus 10. FIG.
[0031]
Embodiment 2. FIG.
The present embodiment relates to a method for calculating the re-loading load amount in the correction control of the first embodiment.
[0032]
FIG. 3 is a control logic flowchart of the stabilization control in the present embodiment, and the stabilization control method will be described with reference to FIG.
[0033]
For example, referring to FIG. 1, when a failure leading to a route break occurs in the power transmission line 2A and a single separation system is generated (meaning that the bus 1A and the bus 1B are divided), the circuit breaker 3A Or by taking in the breaking information of the circuit breaker 3B through the input cables 6A and 6B, the system stabilizing device 10 recognizes the occurrence of a single separated system and performs the stabilization process according to the following steps.
[0034]
Step ST1: Collect data such as system information, bus voltage, load, generator output, and interconnected power flow obtained from the input cables 6C to 6G before system separation occurs.
[0035]
Step ST2: A necessary control amount at the time of occurrence of system separation is calculated based on the data collected in step ST1, and a control amount table prepared in advance is updated.
[0036]
Step ST3: Recognize that the power transmission line 2A is disconnected and becomes a single separated system.
[0037]
Step ST4: Refer to the latest control amount table updated in step ST2, and calculate the necessary control amount of the single isolated system.
[0038]
Step ST5: It is determined whether or not control is required for the single separated system. If control is required, the process proceeds to step ST6, and otherwise the process proceeds to step ST13.
[0039]
Step ST6: According to the control amount calculated in step ST4, the system stabilizing device 10 outputs a command for cutting off a part or all of the loads 8A to 8C or the generators 9A to 9C through the output cable 7A or 7B. (Main control) is performed.
[0040]
Step ST7: After the main control in step 6, the frequency in the separation system after a certain time has elapsed is measured.
[0041]
Step ST8: It is determined whether or not the frequency in the separated system measured in step ST7 is within the allowable value. If it is within the allowable value, the process proceeds to step ST13, and otherwise the process proceeds to step ST9.
[0042]
Step ST9: From the power generation amount, load amount, and convergence frequency in the separation system at this time (when the frequency in the separation system after a certain time has elapsed in step ST7), the following equation (1) ). The system constant KL of the load in the separated system is obtained separately by an online estimation method or an offline estimation method, and the system constant of the power source in the separated system is set in advance.
[0043]
[Equation 5]

[0044]
Step ST10: Based on the above formula (1), the following formula (2) is established, and the recharging load amount PLT is calculated according to the following formula (3) obtained by modifying this formula (2).
[0045]
[Formula 6]

[Expression 7]

[0046]
Step ST11: Select a combination of loads 8A to 8C that exceeds the load amount calculated in step ST10 and is the minimum amount.
[0047]
Step ST12: The system stabilizing device 10 outputs a command to the loads 8A to 8C through the output cable 7A, and performs correction control for re-inserting the combination of loads selected in step ST11.
[0048]
Step ST13: It is determined that all the separated system processes have been completed, and the system stabilizing device 10 is returned to the steady state.
[0049]
As described above, a specific load re-input amount can be calculated with a simple formula, and the calculation load can be reduced.
[0050]
In addition, the isolated system stabilization system which concerns on this Embodiment is provided with the system stabilization apparatus 10 with the means to perform said step ST1 thru | or step ST13. Moreover, it is good also as a structure provided with the execution means of each said step linked with the system | strain stabilization apparatus 10. FIG.
[0051]
Embodiment 3 FIG.
When the system separation occurs in the separation system due to the interruption, not all the recharged loads (feeder lines) hold the load amount before the interruption. For example, it may be assumed that the load itself has dropped due to a shut-off shock.
[0052]
The present embodiment relates to a method for obtaining a return amount of a re-input load.
[0053]
FIG. 4 is a control logic flowchart of the stabilization control in the present embodiment, and the stabilization control method will be described with reference to FIG.
[0054]
For example, referring to FIG. 1, when a failure leading to a route break occurs in the power transmission line 2A and a single separation system is generated (meaning that the bus 1A and the bus 1B are divided), the circuit breaker 3A Or by taking in the breaking information of the circuit breaker 3B through the input cables 6A and 6B, the system stabilizing device 10 recognizes the occurrence of a single separated system and performs the stabilization process according to the following steps.
[0055]
Step ST1: Collect data such as system information, bus voltage, load, generator output, and interconnected power flow obtained from the input cables 6C to 6G before system separation occurs.
[0056]
Step ST2: A necessary control amount at the time of occurrence of system separation is calculated based on the data collected in step ST1, and a control amount table prepared in advance is updated.
[0057]
Step ST3: Recognize that the power transmission line 2A is disconnected and becomes a single separated system.
[0058]
Step ST4: The system stabilizing device 10 takes in the load bus voltage value immediately after the failure measured by the sensor 5A through the input cable 6D, and collates it with FIG. 5 showing the relationship between the load recovery rate (%) and the voltage drop value. Hold the return rate of the blocked load. Note that FIG. 5 is set in advance by simulation or the like.
[0059]
Step ST5: Referring to the latest control amount table updated in step ST2, the necessary control amount of the single isolated system is calculated.
[0060]
Step ST6: It is determined whether or not control is required for the single separated system. If control is required, the process proceeds to step ST7, and otherwise the process proceeds to step ST14.
[0061]
Step ST7: According to the control amount calculated in step ST5, the system stabilizing device 10 outputs a command for cutting off part or all of the loads 8A to 8C or the generators 9A to 9C through the output cable 7A or 7B, and performs control. (Main control) is performed.
[0062]
Step ST8: After the main control in step 6, the frequency in the separated system after a certain time has elapsed is measured.
[0063]
Step ST9: It is determined whether or not the frequency in the separation system measured in step ST8 is within the allowable value. If it is within the allowable value, the process proceeds to step ST14, and otherwise the process proceeds to step ST10.
[0064]
Step ST10: From the power generation amount, load amount and convergence frequency in the separation system at this time (when the frequency in the separation system after a certain time has elapsed in step ST8), the above formula (1 ) (See Embodiment 2). The system constant KL of the load in the separated system is obtained separately by an online estimation method or an offline estimation method, and the system constant of the power source in the separated system is set in advance.
[0065]
Step ST11: Based on the above equation (1), the following equation (4) is established, and the recharging load amount PLT is calculated according to the following equation (5) obtained by modifying this equation (4).
[0066]
[Equation 8]

[Equation 9]

[0067]
Step ST12: When load blocking is performed in the main control performed in step ST7, a combination of loads 8A to 8C that exceeds the load amount calculated in step ST11 and is the minimum amount is selected.
[0068]
Step ST13: The system stabilizing device 10 outputs a command to the loads 8A to 8C through the output cable 7A, and performs correction control for re-inserting the load selected in step ST12.
[0069]
Step ST14: It is determined that all the separated system processes have been completed, and the system stabilizing device 10 is returned to the steady state.
[0070]
As described above, when a load drop occurs due to load interruption or the like, it is possible to consider the return rate of the load (feeder line) to be re-input for those loads, so that higher quality power supply can be performed. .
[0071]
In the isolated system stabilization system according to the present embodiment, the system stabilization apparatus 10 includes means for executing steps ST1 to ST14. Moreover, it is good also as a structure provided with the execution means of each said step linked with the system | strain stabilization apparatus 10. FIG.
[0072]
Embodiment 4 FIG.
The present embodiment relates to a method of using tidal current calculation for calculating the re-input load amount.
[0073]
FIG. 6 is a block diagram showing Embodiment 1 of the separated system stabilization system according to the present invention, where the same reference numerals as those in FIG. 1 denote the same or corresponding parts. In the figure, reference numeral 11 is a phase adjusting device for adjusting the voltage of the load bus 1B by supplying reactive power to the load bus 1B or by using reactive power from the load bus 1B, 12 is a central power supply command station, and 13A is A communication path for transmitting the system information from the central power supply command station 12 to the system stabilizing device 10, and 13 </ b> B are a communication path for transmitting the phased input amount of the phase adjusting equipment 11 to the system stabilizing device 10.
[0074]
FIG. 7 is a control logic flowchart of the stabilization control in this embodiment, and the stabilization control method will be described with reference to FIG.
[0075]
For example, in FIG. 6, when a failure leading to a route break occurs in the power transmission line 2A and a single separation system is generated (meaning that the bus 1A and the bus 1B are cut off), the circuit breaker 3A or the breaker By capturing the cutoff information of the device 3B through the input cables 6A and 6B, the system stabilizing device 10 recognizes the occurrence of the isolated system and performs the stabilization process according to the following steps.
[0076]
Step ST1: Before the system separation occurs, the system information obtained from the input cables 6C to 6G and the communication path 13B, the bus voltage, the load amount, the generator output, the interconnecting power flow and the phased input amount, and transmission in the separated system Data for power flow calculation is collected from information (for example, system capacity) from the central power supply command station 12 obtained through the route 13A.
[0077]
Step ST2: Recognize that the power transmission line 2A is disconnected.
[0078]
Step ST3: Estimate the voltage static characteristics and dropout amount of the load in the separated system using the online data after the occurrence of the system separation.
[0079]
Step ST4: Based on the data collected in step ST1 and the static voltage characteristics and dropout of the load estimated in step ST3, the power flow calculation considering the frequency deviation is performed on the separated system.
[0080]
Step ST5: As a result of the power flow calculation performed in step ST4, it is determined whether or not the frequency in the separated system is within the allowable value. If so, the process proceeds to step ST12. Otherwise, the process proceeds to step ST6. .
[0081]
Step ST6: Assuming that a load interruption pattern (a combination of loads to be interrupted) assumed in advance is executed in accordance with the priority order, the load flow calculation is performed and the load interruption pattern is selected. At this time, the load interruption pattern is previously patterned by another method, and the priority order is also determined in advance.
[0082]
Step ST7: The system stabilizing device 10 performs the load cutoff selected in Step 6 through the output cables 7A and 7C (main control).
[0083]
Step ST8: After the main control is performed, the frequency in the separation system after a certain time has elapsed is measured.
[0084]
Step ST9: It is determined whether or not the frequency in the separation system measured in step ST8 is within the allowable value. If the frequency is within the allowable value, the process proceeds to step ST12. Otherwise, the process proceeds to step ST10.
[0085]
Step ST10: A load flow calculation is performed assuming a combination with another load on the load (feeder line) cut off in step ST7, and a combination of re-input loads closest to the pre-failure frequency is selected.
[0086]
Step ST11: The system stabilizing device 10 passes the output cable 7A, re-inputs the load selected in Step 10, and lowers the frequency in the separated system to an allowable value (correction control).
[0087]
Step ST12: It is determined that all the separated system processes have been completed, and the system stabilization apparatus 10 is returned to the steady state.
[0088]
As described above, in the present embodiment, the load cut off by the main control using the tidal flow calculation is calculated by calculating the reflow amount by the tidal flow calculation, and recharging by the correction control according to this recharging amount. Therefore, the control amount can be minimized and high-quality power can be supplied.
[0089]
In addition, the isolated system stabilization system which concerns on this Embodiment is provided with the means which performs the said step ST1 thru | or step ST12 in the system stabilization apparatus 10. FIG. Moreover, it is good also as a structure provided with the execution means of each said step linked with the system | strain stabilization apparatus 10. FIG.
[0090]
【The invention's effect】
According to the isolated system stabilization method according to the present invention, when the system separation of the separated system in the power system occurs, the power generation supply amount or the load amount of the load in the separated system is controlled by the system stabilization device. In the method of stabilizing a single isolated system that stabilizes the above isolated system,
A first step of calculating a necessary control amount of the separated system separated based on the information before the system separation in the separated system;
A second step of determining whether control is necessary for the separated system separated from the system;
When it is determined in the second step that control is required for the separated system, main control is performed to shut off part or all of the load and the generator according to the necessary control amount calculated in the first step. The third step,
In the second step, when it is determined that control is not required for the separated system, it is determined that the processing of all the separated systems is completed, and the fourth step is performed so that the system stabilizing device is in steady operation.
After the main control in the third step, the fifth step of measuring the frequency in the separation system after a certain time has elapsed,
A sixth step of determining whether or not the frequency in the separated system measured in the fifth step is within an allowable value;
In the sixth step, if the measured frequency in the separated system does not fall within the allowable value, the re-input load amount is calculated based on the measured frequency in the separated system, and the load blocked in the third step A seventh step of re-charging the calculated re-loading load amount with correction control,
In the sixth step, if the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the eighth operation. Step,
Therefore, it is not necessary to shut off a new generator, the control amount can be minimized, and high-quality power can be supplied.
[0091]
In addition, the above re-loading load amount is a load amount that exceeds the load amount calculated by the following equation (3) and is the minimum load amount. Therefore, the load re-loading amount can be calculated by a simple equation. The load on can be reduced.
[Expression 10]

[0092]
In addition, since the re-input load amount exceeds the load amount calculated by the following equation (5) and is the minimum load amount, even when a load drop occurs due to a shock such as load interruption. The load drop can be taken into consideration, and a higher quality power supply can be achieved.
[Expression 11]

[0093]
In addition, in accordance with the occurrence of system separation of the separated system in the power system, the power generation supply amount of the generator in the separated system or the load amount of the load, or the phase control amount of the phase adjusting equipment by the reactive power supply is controlled by the system stabilization device. In the method of stabilizing a single separated system controlled by the above and stabilizing the separated system,
Estimate the static voltage characteristics and dropout of the load in the separated system using the online data after the occurrence of the system separation, the estimated voltage static characteristics and dropout of the load, and information before the system separation in the separated system A first step of performing a power flow calculation considering a frequency deviation with respect to a separated system, based on
A second step of determining whether or not the frequency in the separation system is within an allowable value as a result of the tidal current calculation performed in the first step;
In the above second step, when the frequency in the separated system as a result of the power flow calculation is not within the allowable value, it is assumed that the assumed load breaking pattern (the combination of loads to be blocked) is executed according to the priority order. The third step of performing the load flow calculation and selecting the load shedding pattern,
In the second step, when the frequency in the separated system as a result of the power flow calculation is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the steady operation. The fourth step,
A fifth step in which the load cutoff selected in the third step is performed in the main control;
After the main control in the fifth step, a sixth step of measuring the frequency in the separation system after a certain time has elapsed,
A seventh step for determining whether or not the frequency in the separated system measured in the sixth step is within an allowable value;
In the seventh step, if the measured frequency in the separated system is not within the allowable value, the load flow calculated in the sixth step (feeder line) is assumed to be combined with other loads to calculate the power flow. And an eighth step of selecting the re-loading load combination that is closest to the pre-failure frequency,
A ninth step in which the load cut off in the fifth step is re-charged with the combination of the re-load loads selected in the eighth step in the correction control;
In the seventh step, when the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set in the steady operation. Step,
Therefore, the amount of control can be minimized, and higher quality power supply can be achieved.
[0094]
According to the isolated system stabilization system according to the present invention, when the system separation of the separated system in the power system occurs, the power generation supply amount or the load amount of the load in the separated system is controlled by the system stabilization device. In the single separation system stabilization system for stabilizing the separation system,
A first means for calculating a necessary control amount of the separated system separated based on the information before the system separation in the separated system;
A second means for determining whether or not control is necessary for the separated system separated from the system;
In the second means, when it is determined that control is required for the separated system, main control is performed to shut off part or all of the load and the generator according to the required control amount calculated by the first means. A third means to
In the second means, if it is determined that control is not required for the separated system, it is determined that the processing of all the separated systems is completed, and fourth means for making the system stabilizing device in steady operation,
A fifth means for measuring a frequency in the separation system after a lapse of a fixed time after the main control in the third means;
Sixth means for determining whether or not the frequency in the separation system measured by the fifth means is within an allowable value;
In the sixth means, when the measured frequency in the separated system is not within the allowable value, the re-input load amount is calculated based on the measured frequency in the separated system, and the load blocked by the third means A seventh means for re-inputting the calculated re-input load amount with correction control,
In the sixth means, when the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the eighth operation. means,
Therefore, it is not necessary to shut off a new generator, the control amount can be minimized, and high-quality power can be supplied.
[0095]
In addition, in accordance with the occurrence of system separation of the separated system in the power system, the power generation supply amount of the generator in the separated system or the load amount of the load, or the phase control amount of the phase adjusting equipment by the reactive power supply is controlled by the system stabilization device. In a single separation system stabilization system that is controlled by the above and stabilizes the separation system,
Estimate the static voltage characteristics and dropout of the load in the separated system using the online data after the occurrence of the system separation, the estimated voltage static characteristics and dropout of the load, and information before the system separation in the separated system A first means for performing a power flow calculation considering a frequency deviation with respect to a separated system separated based on
A second means for determining whether or not the frequency in the separation system is within an allowable value as a result of the tidal current calculation performed in the first means;
In the above second means, when it is determined that the frequency in the separated system as a result of the power flow calculation is not within the allowable value, a load interruption pattern (a combination of loads to be interrupted) is executed in accordance with the priority order. Assuming that, a third means for performing load flow calculation and selecting a load shedding pattern,
In the second means, when it is determined that the frequency in the separated system as a result of the power flow calculation is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is A fourth means for steady operation;
A fifth means for performing the load cutoff selected by the third means by the main control;
A sixth means for measuring a frequency in the separation system after a lapse of a fixed time after the main control in the fifth means;
A seventh means for determining whether or not the frequency in the separation system measured by the sixth means is within an allowable value;
In the seventh means, when it is determined that the measured frequency in the separated system is not within the allowable value, a combination with another load is assumed for the load (feeder line) blocked by the sixth means. The eighth means for performing the power flow calculation and selecting the combination of the re-input loads closest to the pre-failure frequency,
A ninth means for re-feeding the load cut off by the fifth means with the combination of re-load loads selected in the eighth means by correction control;
In the seventh means, when it is determined that the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the steady operation. 10th means to
Therefore, the amount of control can be minimized, and higher quality power supply can be achieved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing Embodiment 1 of a separation system stabilization system according to the present invention.
FIG. 2 is a control logic flowchart of stabilization control in the first embodiment.
FIG. 3 is a control logic flowchart of stabilization control in the second embodiment.
FIG. 4 is a control logic flowchart of stabilization control in the third embodiment.
FIG. 5 is a diagram illustrating the relationship between a load recovery rate and a voltage drop value used in the third embodiment.
[Fig. 6] Fig. 6 is a configuration diagram showing a fourth embodiment of the separated system stabilization system according to the present invention.
7 is a control logic flowchart of stabilization control in Embodiment 4. FIG.
FIG. 8 is a block diagram showing a conventional separation system stabilizing device.
[Explanation of symbols]
1A main system bus, 1B load bus, 1C generator bus,
2A, 2B Separated transmission line, 3A-3H circuit breaker,
4A to 4G sensor (current transformer), 5A, 5B sensor (transformer),
6A-6G input cable, 7A-7C output cable, 8A-8C load,
9A-9C generator, 10 system stabilizer, 11 phase adjustment equipment,
12 Central power supply command station, 13A, 13B Communication path.

Claims (6)

Stabilization of a single isolated system that stabilizes the separated system by controlling the power generation supply amount or load load of the generator in the separated system with a system stabilizing device in accordance with the occurrence of system separation of the separated system in the power system In the method
A first step of calculating a necessary control amount of the separated system separated based on the information before the system separation in the separated system;
A second step of determining whether control is necessary for the separated system separated from the system;
When it is determined in the second step that control is required for the separated system, main control is performed to shut off part or all of the load and the generator according to the necessary control amount calculated in the first step. The third step,
In the second step, when it is determined that control is not required for the separated system, it is determined that the processing of all the separated systems is completed, and the fourth step is performed so that the system stabilizing device is in steady operation.
After the main control in the third step, the fifth step of measuring the frequency in the separation system after a certain time has elapsed,
A sixth step of determining whether or not the frequency in the separated system measured in the fifth step is within an allowable value;
In the sixth step, if the measured frequency in the separated system does not fall within the allowable value, the re-input load amount is calculated based on the measured frequency in the separated system, and the load blocked in the third step A seventh step of re-charging the calculated re-loading load amount with correction control,
In the sixth step, if the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the eighth operation. Step,
A method for stabilizing an isolated system characterized by comprising: The method for stabilizing an isolated system according to claim 1, wherein the re-input load amount is a load amount that exceeds the load amount calculated by the following formula (3) and is a minimum amount.

The method for stabilizing a single isolated system according to claim 1, wherein the re-input load amount is a load amount that exceeds the load amount calculated by the following equation (5) and is a minimum amount.

With the occurrence of system separation of the separation system in the power system, the power generation supply amount or load load of the generator in the separation system, or the phase adjustment control amount of the phase adjusting equipment by reactive power supply is controlled by the system stabilization device In the method of stabilizing a single isolated system that stabilizes the above isolated system,
Estimate the static voltage characteristics and dropout of the load in the separated system using the online data after the occurrence of the system separation, the estimated voltage static characteristics and dropout of the load, and information before the system separation in the separated system A first step of performing a power flow calculation considering a frequency deviation with respect to a separated system, based on
A second step of determining whether or not the frequency in the separation system is within an allowable value as a result of the tidal current calculation performed in the first step;
In the above second step, when the frequency in the separated system as a result of the power flow calculation is not within the allowable value, it is assumed that the assumed load breaking pattern (the combination of loads to be blocked) is executed according to the priority order. The third step of performing the load flow calculation and selecting the load shedding pattern,
In the second step, when the frequency in the separated system as a result of the power flow calculation is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the steady operation. The fourth step,
A fifth step in which the load cutoff selected in the third step is performed in the main control;
After the main control in the fifth step, a sixth step of measuring the frequency in the separation system after a certain time has elapsed,
A seventh step for determining whether or not the frequency in the separated system measured in the sixth step is within an allowable value;
In the seventh step, if the measured frequency in the separated system is not within the allowable value, the load flow calculated in the sixth step (feeder line) is assumed to be combined with other loads to calculate the power flow. And an eighth step of selecting the re-loading load combination that is closest to the pre-failure frequency,
A ninth step in which the load cut off in the fifth step is re-charged with the combination of the re-load loads selected in the eighth step in the correction control;
In the seventh step, when the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set in the steady operation. Step,
A method for stabilizing an isolated system characterized by comprising: Stabilization of a single isolated system that stabilizes the separated system by controlling the power generation supply amount or load load of the generator in the separated system with a system stabilizing device in accordance with the occurrence of system separation of the separated system in the power system In the system,
A first means for calculating a necessary control amount of the separated system separated based on the information before the system separation in the separated system;
A second means for determining whether or not control is necessary for the separated system separated from the system;
In the second means, when it is determined that control is required for the separated system, main control is performed to shut off part or all of the load and the generator according to the required control amount calculated by the first means. A third means to
In the second means, if it is determined that control is not required for the separated system, it is determined that the processing of all the separated systems is completed, and fourth means for making the system stabilizing device in steady operation,
A fifth means for measuring a frequency in the separation system after a lapse of a fixed time after the main control in the third means;
Sixth means for determining whether or not the frequency in the separation system measured by the fifth means is within an allowable value;
In the sixth means, when the measured frequency in the separated system is not within the allowable value, the re-input load amount is calculated based on the measured frequency in the separated system, and the load blocked by the third means A seventh means for re-inputting the calculated re-input load amount with correction control,
In the sixth means, when the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the eighth operation. means,
An isolated system stabilization system characterized by comprising: With the occurrence of system separation of the separation system in the power system, the power generation supply amount or load load of the generator in the separation system, or the phase adjustment control amount of the phase adjusting equipment by reactive power supply is controlled by the system stabilization device In the single separation system stabilization system for stabilizing the separation system,
Estimate the static voltage characteristics and dropout of the load in the separated system using the online data after the occurrence of the system separation, the estimated voltage static characteristics and dropout of the load, and information before the system separation in the separated system A first means for performing a power flow calculation considering a frequency deviation with respect to a separated system separated based on
A second means for determining whether or not the frequency in the separation system is within an allowable value as a result of the tidal current calculation performed in the first means;
In the above second means, when it is determined that the frequency in the separated system as a result of the power flow calculation is not within the allowable value, a load interruption pattern (a combination of loads to be interrupted) is executed in accordance with the priority order. Assuming that, a third means for performing load flow calculation and selecting a load shedding pattern,
In the second means, when it is determined that the frequency in the separated system as a result of the power flow calculation is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is A fourth means for steady operation;
A fifth means for performing the load cutoff selected by the third means by the main control;
A sixth means for measuring a frequency in the separation system after a lapse of a fixed time after the main control in the fifth means;
A seventh means for determining whether or not the frequency in the separation system measured by the sixth means is within an allowable value;
In the seventh means, when it is determined that the measured frequency in the separated system is not within the allowable value, a combination with another load is assumed for the load (feeder line) blocked by the sixth means. The eighth means for performing the power flow calculation and selecting the combination of the re-input loads closest to the pre-failure frequency,
A ninth means for re-feeding the load cut off by the fifth means with the combination of re-load loads selected in the eighth means by correction control;
In the seventh means, when it is determined that the measured frequency in the separated system is within the allowable value, it is determined that the processing of all the separated systems is completed, and the system stabilizing device is set to the steady operation. 10th means to
An isolated system stabilization system characterized by comprising:

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