JP4236389B2 - Power control method, power control system, control device, and computer program - Google Patents

Power control method, power control system, control device, and computer program Download PDF

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JP4236389B2
JP4236389B2 JP2001083873A JP2001083873A JP4236389B2 JP 4236389 B2 JP4236389 B2 JP 4236389B2 JP 2001083873 A JP2001083873 A JP 2001083873A JP 2001083873 A JP2001083873 A JP 2001083873A JP 4236389 B2 JP4236389 B2 JP 4236389B2
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幸三 山室
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Osaka Gas Co Ltd
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Description

【０００１】
【発明の属する技術分野】
本発明は外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給し、外部からの受電量を目標値に近づけるべく発電量を制御する電力制御方法、その方法を適用した電力制御システム、そのシステムに用いられる制御装置、及びその装置を実現するためのコンピュータプログラムに関し、特に外部から購入する電力とコージェネレーション設備等の自家発電機を用いて発電した電力とを併用し、電力負荷の電力消費量の変動を見越した上で、自家発電機にて発電した電力の使用率を向上させる電力制御方法、電力制御システム、制御装置、及びコンピュータプログラムに関する。
【０００２】
【従来の技術】
コージェネレーション設備等の自家発電機にて発電した電力及び電力会社から受電する電力を電力負荷へ供給すべく複数の電力系統を連係させて運転する場合、発電量が電力負荷へ供給する量を上回り、電力会社側へ発電した電力が流れる逆潮流が発生しないように、単位時間毎の受電量の下限の基準値を示す最低受電電力値を設定し、設定した最低受電電力値を確保すべく発電量の制御が行われる。
【０００３】
ところが受電した電力及び発電した電力が供給される電力負荷の消費電力は常に変動しており、電力負荷の負荷変動が大きい場合、発電機の発電量の制御が電力負荷の負荷変動に追従することができず、過剰の発電を行って受電量が最低受電電力値を下回り、更には発電量が消費電力を上回って発電した電力を受電側へ送る逆潮流が発生する場合も考えられるため、最低受電電力値から十分に高い余裕を見越した値を受電量の目標値とし、受電量を目標値に近づけるべく発電量を制御する受電一定制御が行われる。
【０００４】
図７は受電一定制御時の発電量及び受電量の経時変化を例示するグラフである。
図７では横軸に時間をとり、縦軸に発電量及び受電量を示す電力量をとって、その経時的な変化を示すものであり、一点鎖線が受電量を示し、実線が発電量及び受電量の合計である電力負荷へ供給する電力量を示しており、実線と一点鎖線との差が発電量を示している。
【０００５】
ｔ1 からｔ2 及びｔ3 からｔ4 における緩やかな負荷変動においては、発電機の制御による発電量の変化が負荷変動に追従しているため、受電量が目標値付近で一定となっているが、ｔ5 、ｔ6 、及びｔ7 の時点においては、負荷変動が急激であるため、発電機の制御による発電量の変化が負荷変動に追従していくことができず、受電量が一時的に変化している。
【０００６】
特にｔ6 及びｔ7 の時点では、受電量が急激に低下し、最低受電電力値付近まで達しており、状況によっては受電量が負の値、即ち逆潮流が発生する場合があることを示している。
受電量が最低受電電力を下回る変動、更には逆潮流を防止するためには、受電量の目標値を高めに設定する必要があり、しかも発電機の追従性能は機械毎に差があり、また負荷変動の状況によって大きく異なるため、最低受電電力値から十分に高い余裕を見越した値を受電量の目標値とすることが通例となっている。
【０００７】
【発明が解決しようとする課題】
しかしながら受電量の目標値を高めに設定するということは、発電機の発電量を低下させて受電量を向上させることであり、電力負荷に供給する電力において、受電による高価な電力の比率を高く、発電による安価な電力の比率を低くするため、エネルギコストの高騰を引き起こすという問題がある。
【０００８】
本発明は斯かる事情に鑑みてなされたものであり、所定期間中における受電電力値が最低受電電力値以下とならなかった場合に受電量の目標値を低くし、受電電力値が最低受電電力値以下となった場合に受電量の目標値を高くするというように受電一定制御における受電量の目標値を動的に変更することで、エネルギコストを低減し、しかも逆潮流を抑制することが可能な電力制御方法、その方法を適用した電力制御システム、そのシステムに用いられる制御装置、及びその装置を実現するためのコンピュータプログラムの提供を目的とする。
【０００９】
【課題を解決するための手段】
第１発明に係る電力制御方法は、外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給し、外部からの受電量を目標値に近づけるべく発電量を制御する電力制御方法において、外部から受電した受電量の単位時間毎の受電量を示す受電電力値を計測し、計測した受電電力値の最低値に基づいて受電量の目標値を変更することを特徴とする。
【００１０】
第２発明に係る電力制御システムは、外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給し、外部からの受電量を目標値に近づけるべく発電量を制御する電力制御システムにおいて、外部から受電した単位時間毎の受電量を示す受電電力値を計測する手段と、計測した受電電力値を、単位時間毎の受電量の下限の基準値を示す最低受電電力値と比較する比較手段と、該比較手段による比較により、所定期間に受電電力値が最低受電電力値以下にならなかったと判断した場合に、受電量の目標値を低くする手段とを備えることを特徴とする。
【００１１】
第３発明に係る電力制御システムは、第２発明において、前記比較手段による比較により、受電電力値が最低受電電力値以下であると判断した場合に、受電量の目標値を高くする手段を更に備えることを特徴とする。
【００１２】
第４発明に係る電力制御システムは、外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給し、外部からの受電量を目標値に近づけるべく発電量を制御する電力制御システムにおいて、発電機の制御を行う制御装置と、該制御装置に公衆通信網を介して接続し、受電量の目標値を管理する管理装置とを備え、前記制御装置は、外部から受電した単位時間毎の受電量を示す受電電力値を受け付ける手段と、受け付けた受電電力値を前記管理装置へ送信する手段とを備え、前記管理装置は、受信した受電電力値を、単位時間毎の受電量の下限の基準値を示す最低受電電力値と比較する手段と、比較した結果に基づき受電量の目標値を変更する変更目標値を導出する手段と、導出した変更目標値を前記制御装置へ送信する手段とを備え、前記制御装置は、更に、受信した変更目標値に基づき、受電量を変更目標値に近づけるべく発電量を制御する手段を備えることを特徴とする。
【００１３】
第５発明に係る制御装置は、外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給するシステムにて、外部からの受電量を目標値に近づけるべく発電機を制御する制御装置において、外部から受電した単位時間毎の受電量を計測した受電電力値を受け付ける手段と、受け付けた受電電力値の最低値を、単位時間毎の受電量の下限の基準値を示す最低受電電力値と比較する手段と、比較した結果に基づいて受電量の目標値を変更する手段とを備えることを特徴とする。
【００１４】
第６発明に係るコンピュータプログラムは、外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給するシステムにて、コンピュータに、外部からの受電量を目標値に近づけるべく発電機を制御させるコンピュータプログラムにおいて、コンピュータに、外部から受電した単位時間毎の受電量を計測した受電電力値を受け付けた場合に、受け付けた受電電力値の最低値を、単位時間毎の受電量の下限の基準値を示す最低受電電力値と比較させる手順と、コンピュータに、比較した結果に基づき受電量の目標値を変更させる手順とを含むことを特徴とする。
【００１５】
本発明ではコージェネレーション設備等の自家発電機にて発電した安価な電力及び電力会社から購入する高価な商用電力を電力負荷へ供給すべく複数の電力系統を連係させて、受電量を目標値に近づける受電一定制御にて運転する場合に、受電電力値及び最低受電電力値を比較した結果に基づいて、受電量の目標値を変更することにより、受電量の目標値を通常の初期値より低く設定することが可能で、発電機の発電による安価な電力の比率を高め、エネルギコストを低減し、しかも逆潮流を抑制した適正な受電量の目標値設定を行うことが可能である。
【００１６】
【発明の実施の形態】
以下、本発明をその実施の形態を示す図面に基づいて詳述する。
実施の形態１．
図１は本発明の実施の形態１における電力制御システムの構成を示すブロック図である。
図中１はコージェネレーション設備等の自家発電を行う発電機であり、発電機１は発電側遮断器２ａを介して主電力線３へ電力を供給しており、発電側遮断器２ａ及び主電力線３の間には、発電側の電圧及び電流を検出する発電電圧計４ａ及び発電電流計５ａが配設されている。
【００１７】
発電電圧計４ａ及び発電電流計５ａが検出した電圧及び電流の値は、発電量を計測する発電電力計６ａへ送られ、発電電力計６ａでは受け付けた電圧値及び電流値に基づいて発電量を計測し、計測した発電量は本発明の制御装置７へ送られる。
そして発電機１から供給される電力とは別に、商用電力として電力会社からも電力を受電し、受電側遮断器２ｂを介して主電力線３へ供給しており、また受電遮断器２ｂ及び主電力線３の間には、受電側の電圧及び電流を検出する受電電圧計４ｂ及び受電電流計５ｂが配設されている。
【００１８】
受電電圧計４ｂ及び受電電流計５ｂが検出した電圧及び電流の値は、受電量を計測する受電電力計６ｂへ送られ、受電電力計６ｂでは受け付けた電圧値及び電流値に基づいて受電量を計測し、計測した受電量は制御装置７へ送られる。
主電力線３には、負荷側遮断器２ｃ，２ｃ，…を介して電力負荷が配設されており、発電機１にて発電した電力及び受電した電力により稼働する。
【００１９】
制御装置７は、装置全体を制御する制御部７１を備え、制御部７１は、プログラム及びデータ等の情報を記録する記録部７２にファームウェアとして記録されている本発明のコンピュータプログラムを読み取り、読み取ったプログラムを動作させることにより、発電電力受付部７３により受け付けた発電量及び受電電力受付部７４により受け付けた受電量に基づいて、受電量を受電目標値に近づけるべく受電一定制御を行うための発電目標値を決定し、決定した発電目標値を、発電目標値指示部７５により発電機１へ送る処理がなされる。
さらに制御装置７は時間を計時する計時部７６を備えている。
【００２０】
制御装置７から発電目標値を受け付けた発電機１は、発電量が発電目標値に近づくように制御される。
なお電力負荷へ供給される電力の量と発電量との差は、受電により賄われるが、電力負荷の消費電力より発電量が大きい場合、電力の超過分が電力会社へ流れる逆潮流が発生するので、これを防止するため、単位時間毎の受電量の下限の基準値を最低受電電力値として設定している。
【００２１】
次に本発明の実施の形態１における電力制御システムにて用いられる発電機１の基本的な運用パターンの例を、図２に示すグラフを用いて説明する。
図２では横軸に時間をとり、縦軸に発電量及び受電量を示す電力量をとって、その経時的な変化を示すものであり、一点鎖線が受電量を示し、実線が発電量及び受電量の合計である電力負荷へ供給する電力量を示しており、実線と一点鎖線との差が発電量を示している。
【００２２】
ｔ1 において、電力負荷が稼働し始めると、電力負荷への供給は先ず受電電力のみで賄われる。
制御装置７では、受電電力計６ｂから受け付けた受電量を監視しており、電力負荷の消費電力が上昇し、受電量が発電機１の定格出力の５０％程度となるｔ2 の時点にて発電機１を起動し、受電量が目標値になるように発電量を制御する受電一定制御による運転を開始させる。
【００２３】
さらに電力負荷の消費電力が上昇し、発電機１の発電量が発電能力の定格出力に到達した時点ｔ3 から、発電機１は定格出力で発電を行い、発電量の不足分を受電量にて補う発電一定制御による運転が開始され、ｔ4 及びｔ5 を経て、電力負荷の消費電力が下降し、受電量が目標値に達したｔ6 の時点から受電一定制御による運転を再開する。
そしてｔ6 からｔ7 及びｔ8 を経てｔ9 までは受電一定制御による運転が行われ、ｔ9 からｔ10及びｔ11を経てｔ12までは発電一定制御による運転が行われ、ｔ12からは受電一定制御による運転が行われる。
また電力負荷の消費電力が発電機１の定格出力の３０％程度となるｔ13の時点で発電機１を停止し、電力負荷は受電のみで稼働する。
【００２４】
次に本発明の実施の形態１における電力制御システムの受電一定制御時の処理を図３に示すフローチャートを用いて説明する。
制御装置７では、発電電圧計４ａ及び発電電流計５ａ並びに発電電力計６ａにて計測された単位時間毎の発電量を示す発電電力値と、受電電圧計４ｂ及び受電電流計５ｂ並びに受電電力計６ｂにて計測された単位時間毎の受電量を示す受電電力値とを受け付け、受け付けた発電電力値及び受電電力値に基づいて、発電機１を制御している。
【００２５】
そして受電一定制御を開始後、時間の計時を開始し（Ｓ１０１）、受電電力値を受け付け（Ｓ１０２）、受け付けた受電電力値を、単位時間毎の受電量の下限の基準値として設定されている最低受電電力値と比較し（Ｓ１０３）、受電電力値が最低受電電力値以下であると判断した場合（Ｓ１０４：Ｙ）、受電量の目標値が所定量分だけ高くなるように再設定し（Ｓ１０５）、計時している時間をリセットして（Ｓ１０６）、ステップＳ１０２に戻り、以降の処理を繰り返す。
【００２６】
ステップＳ１０４において、受電電力値が最低受電電力値以下でないと判断した場合（Ｓ１０４：Ｎ）、計時している時間が所定時間（所定期間）に到達しているか判別し（Ｓ１０７）、所定時間に達していると判断した場合（Ｓ１０８：Ｙ）、受電量の目標値が所定量分だけ低くなるように再設定して（Ｓ１０９）、ステップＳ１０６へ進み、以降の処理を繰り返す。
ステップＳ１０８において、所定時間に達していないと判断した場合（Ｓ１０８：Ｎ）、ステップＳ１０２に戻り、以降の処理を繰り返す。
【００２７】
図４は本発明の実施の形態１における電力制御システムの受電一定制御時における受電量の目標値の変化を例示したグラフである。
図４（ａ）では横軸に時間をとり、縦軸に受電量を示す電力量をとって、その経時的な変化を示すものであり、実線が本発明の電力制御システムにおける受電量の目標値の変化を示し、破線が従来の電力制御システムにおける受電量の目標値の変化を示している。
なお図４（ａ）中に示される円内のグラフを拡大した図が図４（ｂ）であり、図４（ｂ）中では、実際の受電量を示す受電電力値を細線で示している。
【００２８】
従来の受電量の目標値は、最低受電電力値から十分に高い余裕を見越した値が受電量の目標値として設定されており、設定された目標値が動的に変化することはない。
本発明の受電量の目標値は、初期値としては従来と同様の値が設定されているが、時間と共に最低受電電力値付近まで下降し、途中から上昇下降を繰り返している。
上昇下降を繰り返しているのは、図４（ｂ）に示すように受電電力値が最低受電電力値以下となった場合に、目標値が高く変更されるためである。
【００２９】
実施の形態２．
実施の形態２は、実施の形態１において、制御装置７をインターネット等の公衆通信網に接続し、外部のサービス事業体が管理するサーバコンピュータを受電量の目標値を管理する管理装置として用い、目標値を遠隔操作する形態である。
【００３０】
図５は本発明の実施の形態２における電力制御システムの構成を示すブロック図である。
制御装置７は、公衆通信網ＮＷに接続する通信部７７を有しており、公衆通信網ＮＷには、サーバコンピュータを用いた管理装置８が接続されている。
管理装置８は、装置全体を制御するＣＰＵ８１、管理装置８用のコンピュータプログラム及びデータ等の情報を記録する記録手段８２、情報を一時的に記憶するＲＡＭ８３、時間を計時する計時手段８４、並びに公衆通信網ＮＷに接続する通信手段８５を備えている。
なお図１に示す構成要素と同様の構成要素については、実施の形態１を参照するものとし、その説明を省略する。
【００３１】
次に本発明の実施の形態２における電力制御システムの受電一定制御時の処理を図６に示すフローチャートを用いて説明する。
制御装置７では、受電電力値を受け付け（Ｓ２０１）、受け付けた受電電力値を管理装置８へ送信する（Ｓ２０２）。
【００３２】
管理装置８では、受電電力値を受信し（Ｓ２０３）、受信した受電電力値の送信元の制御装置７を特定して、特定した制御装置７に対応付けて記録されている最低受電電力値と、受信した受電電力値を比較し（Ｓ２０４）、比較した結果に基づき受電量の目標値を変更する変更目標値を導出し（Ｓ２０５）、導出した変更目標値を制御装置７へ送信する（Ｓ２０６）。
ステップＳ２０４〜Ｓ２０５の詳細な処理については、実施の形態１におけるステップＳ１０３〜Ｓ１０９の処理を参照するものとし、その説明を省略する。
【００３３】
制御装置７では、変更目標値を受信し（Ｓ２０７）、受信した変更目標値を目標値として再設定し（Ｓ２０８）、変更目標値に近づけるべく発電量を制御する。
なお管理装置８にて導出する変更目標値としては、目標値とすべき数値を導出する場合、受電電力値と共に現状の目標値を送信するか、管理装置８側で目標値を記録しておく必要があるため、目標値そのものではなく、加減幅を導出し、制御装置７にて導出された加減幅に基づき目標値を変更するようにして管理装置８の処理負荷を軽減するようにしてもよい。
【００３４】
また実施の形態１のステップＳ１０７に対応する所定時間到達を判別する処理については、管理装置８にて受信した受電電力値を時間と対応付けて、都度記録しておくようにしてもよいが、管理装置８の記録容量を鑑み、制御装置７にて計時を行い、計時した時間情報を含ませた受電電力値を送信することが望ましい。
【００３５】
前記実施の形態では、受電量の目標値を予め設定されている所定量分増減させる形態を示したが、本発明はこれに限らず、目標値が大きい領域では、減少幅を大きく、増加幅を小さくし、目標値が小さい領域では、増加幅を大きく、減少幅を小さくするというように増減幅が状況に応じて変化するようにしてもよく、更には受電電力値の動きに基づいて都度適正な増減幅を算出するというように詳細な制御を行うようにしてもよい。
【００３６】
【発明の効果】
以上詳述した如く本発明に係る電力制御方法、電力制御システム、制御装置、及びコンピュータプログラムでは、コージェネレーション設備等の自家発電機にて発電した安価な電力及び電力会社から購入する高価な商用電力を電力負荷へ供給すべく複数の電力系統を連係させて、受電量を目標値に近づける受電一定制御にて運転する場合に、受電電力値及び最低受電電力値を比較した結果に基づいて、受電量の目標値を変更することにより、受電量の目標値を通常の初期値より低く設定することが可能で、発電機の発電による安価な電力の比率を高め、エネルギコストを低減し、しかも逆潮流を抑制した適正な受電量の目標値設定を行うことが可能である等、優れた効果を奏する。
【図面の簡単な説明】
【図１】本発明の実施の形態１における電力制御システムの構成を示すブロック図である。
【図２】本発明の実施の形態１における電力制御システムにて用いられる発電機の基本的な運用パターンを例示するグラフである。
【図３】本発明の実施の形態１における電力制御システムの受電一定制御時の処理を示すフローチャートである。
【図４】本発明の実施の形態１における電力制御システムの受電一定制御時における受電量の目標値の変化を例示したグラフである。
【図５】本発明の実施の形態２における電力制御システムの構成を示すブロック図である。
【図６】本発明の実施の形態２における電力制御システムの受電一定制御時の処理を示すフローチャートである。
【図７】受電一定制御時の発電量及び受電量の経時変化を例示するグラフである。
【符号の説明】
１ 発電機
７ 制御装置
８ 管理装置
ＮＷ 公衆通信網[0001]
BACKGROUND OF THE INVENTION
The present invention supplies power received from outside and power generated by a generator to a power load, and a power control method for controlling the amount of power generated so that the amount of power received from outside approaches a target value, and power control using the method Regarding the system, the control device used in the system, and the computer program for realizing the device, in particular, the power load using both the power purchased from the outside and the power generated using a private generator such as a cogeneration facility The present invention relates to a power control method, a power control system, a control device, and a computer program for improving the usage rate of power generated by a private power generator in anticipation of fluctuations in power consumption.
[0002]
[Prior art]
When operating multiple power systems in conjunction with each other to supply power generated by a private generator such as a cogeneration facility and power received from a power company to the power load, the amount of power generation exceeds the amount supplied to the power load. Set a minimum received power value that indicates the reference value of the lower limit of the amount of power received per unit time, and generate power in order to ensure the set minimum received power value, so that there is no reverse power flow to the power company The amount is controlled.
[0003]
However, the received power and the power consumption of the power load to which the generated power is supplied constantly fluctuate. When the load fluctuation of the power load is large, the control of the power generation amount of the generator should follow the load fluctuation of the power load. However, there is a possibility that a reverse power flow may occur in which excessive power generation occurs and the amount of received power falls below the minimum received power value, and further, the generated power exceeds the power consumption and the generated power is sent to the power receiving side. A power reception constant control for controlling the power generation amount so as to bring the power reception amount closer to the target value is performed by setting a value that allows for a sufficiently high margin from the power reception value as a target value of the power reception amount.
[0004]
FIG. 7 is a graph illustrating the amount of power generation and the change over time of the amount of power received during constant power reception control.
In FIG. 7, the horizontal axis represents time, the vertical axis represents the amount of power indicating the amount of power generation and the amount of power received, and changes over time are shown. The dashed line represents the amount of power received, the solid line represents the amount of power generation and The amount of power supplied to the power load, which is the total amount of power received, is shown, and the difference between the solid line and the one-dot chain line shows the amount of power generation.
[0005]
In gradual load fluctuations from t 1 to t 2 and from t 3 to t 4, the amount of power received is constant near the target value because the change in the amount of power generated by the control of the generator follows the load fluctuation. However, at t 5 , t 6 , and t 7 , the load fluctuation is abrupt. Therefore, the change in the amount of power generated by the control of the generator cannot follow the load fluctuation, and the amount of power received temporarily Is changing.
[0006]
In particular, at t 6 and t 7, the amount of power received decreases sharply and reaches the vicinity of the minimum received power value, indicating that the amount of received power may be negative, that is, reverse power flow may occur depending on the situation. ing.
In order to prevent fluctuations in the amount of received power below the minimum received power, and also reverse power flow, it is necessary to set the target value of the received power higher, and the follow-up performance of the generator varies from machine to machine. Since it varies greatly depending on the load fluctuation situation, it is customary to set a value that allows for a sufficiently high margin from the minimum received power value as the target value of the received power.
[0007]
[Problems to be solved by the invention]
However, setting the target value of power reception to a high value means improving the power reception amount by reducing the power generation amount of the generator. In the power supplied to the power load, the ratio of expensive power by power reception is increased. In order to reduce the ratio of cheap power generated by power generation, there is a problem that the energy cost increases.
[0008]
The present invention has been made in view of such circumstances, and when the received power value during a predetermined period does not fall below the minimum received power value, the target value of the received power is lowered, and the received power value is the lowest received power. By dynamically changing the target value of the received power in the constant power reception control so that the target value of the received power is increased when the value is lower than the value, the energy cost can be reduced and the reverse power flow can be suppressed. An object is to provide a possible power control method, a power control system to which the method is applied, a control device used in the system, and a computer program for realizing the device.
[0009]
[Means for Solving the Problems]
A power control method according to a first aspect of the present invention is a power control method for supplying power received from outside and power generated by a generator to a power load, and controlling the power generation amount so that the amount of power received from the outside approaches a target value. Measured is a received power value indicating the received power amount per unit time of the received power amount received from the outside, and changes the target value of the received power amount based on the minimum value of the measured received power value.
[0010]
A power control system according to a second aspect of the present invention is a power control system that supplies power received from outside and power generated by a generator to a power load, and controls the amount of power generated so that the amount of power received from the outside approaches a target value. A means for measuring the received power value indicating the received power amount per unit time received from the outside, and comparing the measured received power value with the minimum received power value indicating the lower limit reference value of the received power amount per unit time And means for lowering the target value of the amount of received power when it is determined by comparison by the comparison means that the received power value has not fallen below the minimum received power value during a predetermined period.
[0011]
The power control system according to a third aspect of the present invention is the power control system according to the second aspect, further comprising means for increasing the target value of the amount of received power when it is determined by the comparison by the comparison means that the received power value is less than or equal to the minimum received power value. It is characterized by providing.
[0012]
A power control system according to a fourth aspect of the present invention is a power control system that supplies power received from outside and power generated by a generator to a power load, and controls the amount of power generated so that the amount of power received from outside approaches a target value. A control device that controls the generator, and a management device that is connected to the control device via a public communication network and manages a target value of the amount of power received. Means for receiving the received power value indicating the received power amount and means for transmitting the received received power value to the management device, wherein the management device sets the received received power value as a lower limit of the received power amount per unit time. Means for comparing with a minimum received power value indicating the reference value of the power, means for deriving a change target value for changing the target value of the amount of power received based on the comparison result, and means for transmitting the derived change target value to the control device And be prepared The control device further based on the change target value received, characterized in that it comprises means for controlling the power generation amount to approach the received power amount to change the target value.
[0013]
A control device according to a fifth aspect of the present invention is a control device for controlling a generator so that the amount of power received from the outside approaches a target value in a system that supplies power received from outside and power generated by the generator to a power load. Means for receiving the received power value obtained by measuring the amount of received power per unit time received from the outside, and the minimum received power value indicating the reference value of the lower limit of the received power amount per unit time as the minimum value of the received power value received And means for changing the target value of the amount of received power based on the comparison result.
[0014]
A computer program according to a sixth aspect of the invention is a system for supplying electric power received from outside and electric power generated by a generator to an electric power load, and controls the generator so that the amount of electric power received from the outside approaches a target value. In the computer program to be executed, when the received power value obtained by measuring the received power amount per unit time received from the outside is received by the computer, the minimum value of the received received power value is set as a reference for the lower limit of the received power amount per unit time. It includes a procedure for comparing with a minimum received power value indicating a value, and a procedure for causing a computer to change a target value of the amount of received power based on the comparison result.
[0015]
In the present invention, a plurality of power systems are linked in order to supply inexpensive electric power generated by a private generator such as a cogeneration facility and expensive commercial electric power purchased from an electric power company to an electric power load, and the received power amount is set to a target value. When operating with constant power reception control, the power reception target value is lower than the normal initial value by changing the power reception target value based on the result of comparing the received power value and the minimum received power value. It is possible to set a target value of an appropriate amount of power received by increasing the ratio of inexpensive power generated by the generator, reducing the energy cost, and suppressing reverse power flow.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a power control system according to Embodiment 1 of the present invention.
In the figure, reference numeral 1 denotes a generator that performs in-house power generation such as a cogeneration facility. The generator 1 supplies power to the main power line 3 via the power generation circuit breaker 2a, and the power generation circuit breaker 2a and the main power line 3 Between them, a power generation voltmeter 4a and a power generation ammeter 5a for detecting the voltage and current on the power generation side are arranged.
[0017]
The voltage and current values detected by the power generation voltmeter 4a and the power generation ammeter 5a are sent to the power generation meter 6a for measuring the power generation amount. The power generation meter 6a calculates the power generation amount based on the received voltage value and current value. The measured power generation amount is sent to the control device 7 of the present invention.
In addition to the power supplied from the generator 1, the power is also received from the power company as commercial power and supplied to the main power line 3 via the power receiving side circuit breaker 2b. The power receiving circuit breaker 2b and the main power line are also supplied. 3, a power receiving voltmeter 4 b and a power receiving ammeter 5 b for detecting the voltage and current on the power receiving side are disposed.
[0018]
The voltage and current values detected by the receiving voltmeter 4b and the receiving ammeter 5b are sent to the receiving wattmeter 6b that measures the amount of received power, and the receiving wattmeter 6b determines the amount of received power based on the received voltage value and current value. The measured power reception amount is sent to the control device 7.
The main power line 3 is provided with a power load via load-side circuit breakers 2c, 2c,..., And operates with power generated by the generator 1 and received power.
[0019]
The control device 7 includes a control unit 71 that controls the entire device. The control unit 71 reads and reads the computer program of the present invention recorded as firmware in a recording unit 72 that records information such as programs and data. Based on the amount of power received by the generated power reception unit 73 and the amount of power received by the received power reception unit 74, by operating the program, a power generation target for performing constant power reception control to bring the power reception amount closer to the power reception target value A value is determined, and the determined power generation target value is sent to the generator 1 by the power generation target value instructing unit 75.
Furthermore, the control device 7 includes a time measuring unit 76 that measures time.
[0020]
The generator 1 that has received the power generation target value from the control device 7 is controlled such that the power generation amount approaches the power generation target value.
The difference between the amount of power supplied to the power load and the amount of power generated is covered by power reception, but if the amount of power generated is greater than the power consumed by the power load, a reverse flow will occur in which the excess power flows to the power company. Therefore, in order to prevent this, the reference value for the lower limit of the amount of received power per unit time is set as the minimum received power value.
[0021]
Next, an example of a basic operation pattern of the generator 1 used in the power control system according to Embodiment 1 of the present invention will be described using the graph shown in FIG.
In FIG. 2, the horizontal axis represents time, the vertical axis represents the amount of power indicating the amount of power generation and the amount of power received, and the change over time is shown. The dashed line represents the amount of power received, the solid line represents the amount of power generation and The amount of power supplied to the power load, which is the total amount of power received, is shown, and the difference between the solid line and the one-dot chain line shows the amount of power generation.
[0022]
In t 1, when the power load begins to operate, the supply of the power load is first covered only by received power.
The control device 7 monitors the received power amount received from the reception power meter 6b, increases the power consumption of the power load, the amount of power reception at the time of t 2 which is 50% of the rated output of the generator 1 The generator 1 is started, and the operation by power reception constant control for controlling the power generation amount so that the power reception amount becomes a target value is started.
[0023]
Furthermore the power consumption of the power load increases, from the time t 3 when the power generation amount of the generator 1 has reached the rated output of the power generation capacity, the generator 1 performs electric at rated output, the received power amount to shortage of the generated power quantity Then, the operation by the constant power generation control is started, and after t 4 and t 5 , the power consumption of the power load decreases, and the operation by the constant power reception control is resumed from the time t 6 when the power reception amount reaches the target value.
From t 6 through t 7 and t 8 to t 9, operation is performed by constant power reception control, from t 9 through t 10 and t 11 through t 12, operation is performed by constant power generation control, and from t 12 Is operated under constant power reception control.
The power consumption of the power load to stop the generator 1 at time t 13 which is 30% of the rated output of the generator 1, power load is running only at the receiving.
[0024]
Next, processing during power reception constant control of the power control system according to Embodiment 1 of the present invention will be described using the flowchart shown in FIG.
In the control device 7, the generated voltmeter 4a, the generated ammeter 5a, and the generated power value indicating the amount of power generated per unit time measured by the generated power meter 6a, the received voltmeter 4b, the received ammeter 5b, and the received wattmeter The received power value indicating the received power amount per unit time measured in 6b is received, and the generator 1 is controlled based on the received generated power value and the received power value.
[0025]
Then, after starting the constant power reception control, time measurement is started (S101), the received power value is received (S102), and the received power value is set as a reference value for the lower limit of the received power amount per unit time. Compared with the minimum received power value (S103), if it is determined that the received power value is less than or equal to the minimum received power value (S104: Y), the target value of the received power is reset to be higher by a predetermined amount ( (S105) The time being measured is reset (S106), the process returns to step S102, and the subsequent processing is repeated.
[0026]
If it is determined in step S104 that the received power value is not less than or equal to the minimum received power value (S104: N), it is determined whether or not the time being measured has reached a predetermined time (predetermined period) (S107). When it is determined that the power has reached (S108: Y), the power reception target value is reset so as to be lower by a predetermined amount (S109), the process proceeds to step S106, and the subsequent processing is repeated.
If it is determined in step S108 that the predetermined time has not been reached (S108: N), the process returns to step S102 and the subsequent processing is repeated.
[0027]
FIG. 4 is a graph illustrating a change in the target value of the amount of received power during constant power reception control of the power control system according to Embodiment 1 of the present invention.
In FIG. 4A, the horizontal axis indicates time and the vertical axis indicates the amount of received power, and the change over time is shown. The solid line indicates the target of the received amount in the power control system of the present invention. The change of the value is shown, and the broken line shows the change of the target value of the power reception amount in the conventional power control system.
Note that FIG. 4B is an enlarged view of the graph in the circle shown in FIG. 4A, and in FIG. 4B, the received power value indicating the actual received power amount is indicated by a thin line. .
[0028]
As the conventional target value of the received power, a value that allows for a sufficiently high margin from the minimum received power value is set as the target value of the received power, and the set target value does not change dynamically.
The target value of the amount of power received according to the present invention is set to the same value as the conventional value as an initial value, but it decreases to the vicinity of the lowest received power value with time and repeats rising and falling from the middle.
The reason why the increase and decrease are repeated is that the target value is changed to be high when the received power value is equal to or lower than the minimum received power value as shown in FIG.
[0029]
Embodiment 2. FIG.
In the second embodiment, the control device 7 is connected to a public communication network such as the Internet in the first embodiment, and a server computer managed by an external service entity is used as a management device for managing the target value of the amount of received power. The target value is remotely controlled.
[0030]
FIG. 5 is a block diagram showing the configuration of the power control system according to Embodiment 2 of the present invention.
The control device 7 has a communication unit 77 connected to the public communication network NW, and a management device 8 using a server computer is connected to the public communication network NW.
The management apparatus 8 includes a CPU 81 for controlling the entire apparatus, a recording means 82 for recording information such as a computer program and data for the management apparatus 8, a RAM 83 for temporarily storing information, a timing means 84 for measuring time, and a public Communication means 85 for connecting to the communication network NW is provided.
Note that the same constituent elements as those shown in FIG. 1 are referred to in the first embodiment, and the description thereof is omitted.
[0031]
Next, processing during power reception constant control of the power control system according to Embodiment 2 of the present invention will be described with reference to the flowchart shown in FIG.
The control device 7 receives the received power value (S201), and transmits the received power value to the management device 8 (S202).
[0032]
The management device 8 receives the received power value (S203), specifies the control device 7 that is the transmission source of the received received power value, and the minimum received power value recorded in association with the specified control device 7. The received power values are compared (S204), a change target value for changing the target value of the received power is derived based on the comparison result (S205), and the derived change target value is transmitted to the control device 7 (S206). ).
For detailed processing in steps S204 to S205, the processing in steps S103 to S109 in the first embodiment is referred to, and the description thereof is omitted.
[0033]
The control device 7 receives the change target value (S207), resets the received change target value as the target value (S208), and controls the power generation amount so as to approach the change target value.
In addition, as a change target value derived | led-out in the management apparatus 8, when deriving the numerical value which should be made into a target value, the present target value is transmitted with a received power value, or the target value is recorded on the management apparatus 8 side. Therefore, instead of the target value itself, an increase / decrease is derived, and the target value is changed based on the increase / decrease derived by the control device 7 so as to reduce the processing load of the management device 8. Good.
[0034]
In addition, regarding the process of determining the arrival of the predetermined time corresponding to step S107 of the first embodiment, the received power value received by the management device 8 may be associated with time and recorded each time. In view of the recording capacity of the management device 8, it is desirable that the control device 7 measures time and transmits the received power value including the time information.
[0035]
In the above-described embodiment, the target value of the power reception amount is increased or decreased by a predetermined amount. However, the present invention is not limited to this, and the decrease amount is increased and the increase amount is increased in a region where the target value is large. In a region where the target value is small, the increase / decrease range may change according to the situation, such as increasing the increase range and decreasing the decrease range, and further based on the movement of the received power value. Detailed control may be performed such that an appropriate increase / decrease width is calculated.
[0036]
【The invention's effect】
As described above in detail, in the power control method, power control system, control device, and computer program according to the present invention, inexpensive power generated by a private generator such as a cogeneration facility and expensive commercial power purchased from a power company. Based on the result of comparing the received power value and the minimum received power value when operating with constant power reception control that links multiple power systems to supply power to the load By changing the target value of the amount, it is possible to set the target value of the received power lower than the normal initial value, increase the ratio of cheap power generated by the generator, reduce the energy cost, and vice versa It is possible to set a target value for an appropriate amount of power received while suppressing power flow.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a power control system according to Embodiment 1 of the present invention.
FIG. 2 is a graph illustrating a basic operation pattern of a generator used in the power control system according to the first embodiment of the present invention.
FIG. 3 is a flowchart showing processing during power reception constant control of the power control system according to Embodiment 1 of the present invention.
FIG. 4 is a graph illustrating a change in a target value of a power reception amount during constant power reception control of the power control system according to the first embodiment of the present invention.
FIG. 5 is a block diagram showing a configuration of a power control system according to Embodiment 2 of the present invention.
FIG. 6 is a flowchart showing processing during power reception constant control of the power control system according to the second embodiment of the present invention.
FIG. 7 is a graph illustrating a power generation amount during power reception constant control and a change over time of the power reception amount.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Generator 7 Control apparatus 8 Management apparatus NW Public communication network

Claims (6)

外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給し、外部からの受電量を目標値に近づけるべく発電量を制御する電力制御方法において、
外部から受電した受電量の単位時間毎の受電量を示す受電電力値を計測し、
計測した受電電力値の最低値に基づいて受電量の目標値を変更する
ことを特徴とする電力制御方法。In the power control method of supplying power received from the outside and power generated by the generator to the power load and controlling the amount of power generated so that the amount of power received from outside approaches the target value,
Measure the received power value indicating the amount of power received per unit time of the amount of power received from the outside,
A power control method characterized by changing a target value of received power based on a measured minimum value of received power. 外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給し、外部からの受電量を目標値に近づけるべく発電量を制御する電力制御システムにおいて、
外部から受電した単位時間毎の受電量を示す受電電力値を計測する手段と、
計測した受電電力値を、単位時間毎の受電量の下限の基準値を示す最低受電電力値と比較する比較手段と、
該比較手段による比較により、所定期間に受電電力値が最低受電電力値以下にならなかったと判断した場合に、受電量の目標値を低くする手段と
を備えることを特徴とする電力制御システム。In the power control system that supplies the power received from the outside and the power generated by the generator to the power load, and controls the amount of power generated so that the amount of power received from the outside approaches the target value,
Means for measuring a received power value indicating a received power amount per unit time received from the outside;
Comparing means for comparing the measured received power value with a minimum received power value indicating a lower limit reference value of the received power amount per unit time;
A power control system comprising: means for lowering a target value of the amount of received power when it is determined by comparison by the comparison means that the received power value has not fallen below the minimum received power value during a predetermined period. 前記比較手段による比較により、受電電力値が最低受電電力値以下であると判断した場合に、受電量の目標値を高くする手段を更に備えることを特徴とする請求項２に記載の電力制御システム。3. The power control system according to claim 2, further comprising means for increasing the target value of the amount of received power when it is determined by the comparison by the comparison means that the received power value is equal to or lower than the minimum received power value. . 外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給し、外部からの受電量を目標値に近づけるべく発電量を制御する電力制御システムにおいて、
発電機の制御を行う制御装置と、
該制御装置に公衆通信網を介して接続し、受電量の目標値を管理する管理装置と
を備え、
前記制御装置は、
外部から受電した単位時間毎の受電量を示す受電電力値を受け付ける手段と、
受け付けた受電電力値を前記管理装置へ送信する手段と
を備え、
前記管理装置は、
受信した受電電力値を、単位時間毎の受電量の下限の基準値を示す最低受電電力値と比較する手段と、
比較した結果に基づき受電量の目標値を変更する変更目標値を導出する手段と、
導出した変更目標値を前記制御装置へ送信する手段と
を備え、
前記制御装置は、更に、
受信した変更目標値に基づき、受電量を変更目標値に近づけるべく発電量を制御する手段を備える
ことを特徴とする電力制御システム。In the power control system that supplies the power received from the outside and the power generated by the generator to the power load, and controls the amount of power generated so that the amount of power received from the outside approaches the target value,
A control device for controlling the generator;
A management device connected to the control device via a public communication network and managing a target value of received power;
The controller is
Means for receiving a received power value indicating a received power amount per unit time received from outside;
Means for transmitting the received received power value to the management device,
The management device
Means for comparing the received power value received with a minimum received power value indicating a reference value of a lower limit of the amount of power received per unit time;
Means for deriving a change target value for changing the power reception target value based on the comparison result;
Means for transmitting the derived change target value to the control device,
The control device further includes:
A power control system comprising: means for controlling a power generation amount so that a power reception amount approaches a change target value based on a received change target value. 外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給するシステムにて、外部からの受電量を目標値に近づけるべく発電機を制御する制御装置において、
外部から受電した単位時間毎の受電量を計測した受電電力値を受け付ける手段と、
受け付けた受電電力値の最低値を、単位時間毎の受電量の下限の基準値を示す最低受電電力値と比較する手段と、
比較した結果に基づいて受電量の目標値を変更する手段と
を備えることを特徴とする制御装置。In a system for controlling the generator to bring the amount of power received from the outside closer to the target value in a system that supplies power received from outside and power generated by the generator to the power load,
Means for receiving a received power value obtained by measuring a received power amount per unit time received from outside;
Means for comparing the lowest value of the received power value received with the lowest received power value indicating the reference value of the lower limit of the received power amount per unit time;
A control device comprising: means for changing a target value of the amount of received power based on a result of the comparison. 外部から受電する電力及び発電機にて発電した電力を電力負荷へ供給するシステムにて、コンピュータに、外部からの受電量を目標値に近づけるべく発電機を制御させるコンピュータプログラムにおいて、
コンピュータに、外部から受電した単位時間毎の受電量を計測した受電電力値を受け付けた場合に、受け付けた受電電力値の最低値を、単位時間毎の受電量の下限の基準値を示す最低受電電力値と比較させる手順と、
コンピュータに、比較した結果に基づき受電量の目標値を変更させる手順と
を含むことを特徴とするコンピュータプログラム。In a system for supplying power received from outside and power generated by a generator to a power load, a computer program for controlling a generator to bring the amount of power received from outside close to a target value,
When the computer receives a received power value obtained by measuring the amount of power received per unit time received from the outside, the minimum value of the received power value received is the lowest received power value indicating the reference value of the lower limit of the received power amount per unit time. The procedure to compare with the power value,
A computer program comprising: causing a computer to change a target value of the amount of received power based on a comparison result.
JP2001083873A 2001-03-22 2001-03-22 Power control method, power control system, control device, and computer program Expired - Fee Related JP4236389B2 (en)

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