JP4170565B2 - Power fluctuation smoothing apparatus and control method of distributed power supply system including the same - Google Patents

Power fluctuation smoothing apparatus and control method of distributed power supply system including the same Download PDF

Info

Publication number
JP4170565B2
JP4170565B2 JP2000198287A JP2000198287A JP4170565B2 JP 4170565 B2 JP4170565 B2 JP 4170565B2 JP 2000198287 A JP2000198287 A JP 2000198287A JP 2000198287 A JP2000198287 A JP 2000198287A JP 4170565 B2 JP4170565 B2 JP 4170565B2
Authority
JP
Japan
Prior art keywords
power
output
value
distributed power
power supply
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
JP2000198287A
Other languages
Japanese (ja)
Other versions
JP2002017044A (en
Inventor
武彦 松岡
勝利 宮島
裕政 久保
徳行 諸富
剛 平野
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kansai Electric Power Co Inc
Daihen Corp
Original Assignee
Kansai Electric Power Co Inc
Daihen Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kansai Electric Power Co Inc, Daihen Corp filed Critical Kansai Electric Power Co Inc
Priority to JP2000198287A priority Critical patent/JP4170565B2/en
Publication of JP2002017044A publication Critical patent/JP2002017044A/en
Application granted granted Critical
Publication of JP4170565B2 publication Critical patent/JP4170565B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/76—Power conversion electric or electronic aspects
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E70/00—Other energy conversion or management systems reducing GHG emissions
    • Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin

Landscapes

  • Supply And Distribution Of Alternating Current (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)
  • Control Of Electrical Variables (AREA)

Description

【０００１】
【発明の属する技術分野】
本発明は、風力発電装置や太陽光発電装置などの分散電源による電力変動を平滑化する電力変動平滑化装置及びそれを備えた分散電源システムの制御方法に関する。
【０００２】
【従来の技術】
近年、環境問題等から風力発電装置や太陽光発電装置のような自然エネルギーを利用する分散電源が電力系統に連系されるようになった。これらの自然エネルギーを利用した分散電源は出力が不安定であり、この電力変動が連系する電力系統の電圧変動や周波数変動を引き起こし、電力系統につながる負荷に悪影響を及ぼす恐れがあった。この対策として提案された、分散電源として太陽光発電装置を用いた場合における電力変動を平滑化するための従来の電力変動平滑化装置及びそれを備えた分散電源システムについて以下に説明する。図８において、分散電源システム１０は、分散電源９と、分散電源９による電力変動を平滑化するための電力変動平滑化装置１と、直流電力を交流電力に変換する電力変換装置１５とから構成され、電源１３の電力系統１２に接続されている。電力変動平滑化装置１は、分散電源９の発生電力を蓄える蓄電部２と、分散電源９の出力を蓄電部２へ充電したり、蓄電部２に蓄えられた電力を電力系統１２側に放電する充放電部３と、電力変動平滑化装置１全体を制御する制御部４とから構成されている。制御部４は、分散電源９の出力を検出する出力検出部５と、出力検出部５から得られる分散電源９の出力の単位時間内における移動平均値を求める目標値設定部７と、目標値設定部７からの信号に基づき充放電部３を作動させる充放電制御部８とから構成されている。以上のような構成を有する分散電源システム１０は、分散電源９の出力を計測して単位時間内における分散電源９の出力の移動平均値を求め、分散電源９の発電電力が移動平均値を上回ったときには、その余剰分を蓄電部２に充電し、分散電源９の発電電力が移動平均値を下回ったときには、その不足分を蓄電部２から放電して、分散電源９による電力変動を平滑化している。
【０００３】
【発明が解決しようとする課題】
しかしながら、このシステムでは、単位時間内における分散電源９の出力の移動平均値を目標値にすることにより、充電量と放電量が平均的に等しいと仮定しているが、実際には充放電の際に蓄電部２や充放電部３等で損失が発生するため、蓄電部２に蓄えられる平均的なエネルギーは徐々に減少して蓄電量が不足状態に陥り、分散電源９の出力の移動平均値である目標値からの不足分を供給できないため、電力変動を抑制できない場合が発生する。また、逆に移動平均値を上回る量が下回る量より大きい場合は、蓄電部２に蓄えられた電力が徐々に増加し、蓄電部２が満充電状態になると、分散電源９の出力が移動平均値より上回ってもその余剰分を蓄電部２に充電できないため、電力変動を抑制できない恐れがある。
【０００４】
本発明は、蓄電部の蓄電量が不足したり、満充電になるのを防止して、確実に風力発電装置や太陽光発電装置などの分散電源による電力系統への出力変動を平滑化する電力変動平滑化装置を提供することを課題としている。
本発明はまた、上記電力変動平滑化装置を備えた分散電源システムの制御方法を提供することを課題としている。
【０００５】
【課題を解決するための手段】
本発明は、次のような手段によって上述した課題を解決している。
本発明の請求項１に記載の発明は、蓄電部、充放電部及び制御部からなり、分散電源とともに電力系統に接続される電力変動平滑化装置において、制御部が、分散電源の出力を検出する出力検出部と、蓄電部の蓄電量を検出する蓄電量検出部と、分散電源の出力の予め設定された期間の移動平均値を、蓄電量または蓄電量の代替値に応じて、予め設定された調整値または補正係数で補正して、電力系統側への出力目標値を設定する目標値設定部と、分散電源の出力と出力目標値とを比較して、または電力系統側への出力をフィードバックして電力系統側への出力が出力目標値になるように充放電部を制御する充放電制御部とを備えたことを特徴としており、これにより次のような作用を有する。すなわち、制御部が、分散電源の出力を検出する出力検出部と、蓄電部の蓄電量を検出する蓄電量検出部と、分散電源の出力の予め設定された期間の移動平均値を、蓄電量または蓄電量の代替値に応じて、予め設定された調整値または補正係数で補正して、電力系統側への出力目標値を設定する目標値設定部と、分散電源の出力と出力目標値とを比較して、または電力系統側への出力をフィードバックして電力系統側への出力が出力目標値になるように充放電部を制御する充放電制御部とを備えているので、蓄電部の蓄電量不足や満充電状態になるのを防止できる。
【０００６】
本発明の請求項２に記載の発明は、分散電源、蓄電部、充放電部及び制御部からなり、制御部が分散電源の出力を検出する出力検出部と、蓄電部の蓄電量を検出する蓄電量検出部と、分散電源の出力の予め設定された期間の移動平均値を、蓄電量または蓄電量の代替値に応じて、予め設定された調整値または補正係数で補正して、電力系統側への出力目標値を設定する目標値設定部と、分散電源の出力と出力目標値とを比較して、または電力系統側への出力をフィードバックして電力系統側への出力が出力目標値になるように充放電部を制御する充放電制御部とからなる電力変動平滑化装置とを備えて、電力系統に接続される分散電源システムの制御方法において、分散電源の出力と蓄電部の蓄電量を検出し、分散電源の出力の予め設定された期間の移動平均値を求め、蓄電量または蓄電量の代替値に応じて、予め設定された調整値または補正係数で移動平均値を補正して前記出力目標値を設定し、分散電源の出力が出力目標値よりも大きいときは、その余剰分を蓄電部に充電し、分散電源の出力が出力目標値よりも小さいときは、その不足分を蓄電部から放電して、電力系統側への出力が出力目標値になるように制御することを特徴としており、これにより次のような作用を有する。すなわち、分散電源の出力と蓄電部の蓄電量を検出し、分散電源の出力の予め設定された期間の移動平均値を求め、蓄電量または蓄電量の代替値に応じて、予め設定された調整値または補正係数で移動平均値を補正して前記出力目標値を設定し、分散電源の出力が出力目標値よりも大きいときは、その余剰分を蓄電部に充電し、分散電源の出力が出力目標値よりも小さいときは、その不足分を蓄電部から放電して、電力系統側への出力が出力目標値になるように制御するので、蓄電部の蓄電量不足や満充電状態になるのを防止できる。
【０００７】
本発明の請求項３に記載の発明は、請求項２に記載の分散電源システムの制御方法であって、蓄電量または蓄電量の代替値の上限値と下限値とを予め設定し、蓄電量または蓄電量の代替値が上限値より大きいときは、出力目標値が移動平均値よりも大きくなるように調整値または補正係数を設定し、蓄電量または蓄電量の代替値が上限値と下限値の間にあるときは、調整値をゼロに設定するか、または補正係数を１に設定し、蓄電量または蓄電量の代替値が下限値より小さいときは、出力目標値が移動平均値よりも小さくなるように調整値または補正係数を設定することを特徴としており、これにより次のような作用を有する。すなわち、蓄電量または蓄電量の代替値の上限値と下限値とを予め設定し、蓄電量または蓄電量の代替値が上限値より大きいときは、出力目標値が移動平均値よりも大きくなるように調整値または補正係数を設定し、蓄電量または蓄電量の代替値が上限値と下限値の間にあるときは、調整値をゼロに設定するか、または補正係数を１に設定し、蓄電量または蓄電量の代替値が下限値より小さいときは、出力目標値が移動平均値よりも小さくなるように調整値または補正係数を設定するので、蓄電部の蓄電量不足や満充電状態になるのを防止できる。
【０００８】
本発明の請求項４に記載の発明は、請求項２に記載の分散電源システムの制御方法であって、蓄電部の使用可能な蓄電量の範囲内に下限値を予め設定し、蓄電量または蓄電量の代替値が、下限値よりも小さいときは、補正係数をゼロに設定し、蓄電量または蓄電量の代替値が、使用可能な蓄電量の範囲の中央のときに補正係数を１に設定し、かつ、蓄電量が増加するとともに大きくなるように設定することを特徴としており、これにより次のような作用を有する。すなわち、蓄電部の使用可能な蓄電量の範囲内に下限値を予め設定し、蓄電量または蓄電量の代替値が、下限値よりも小さいときは、補正係数をゼロに設定し、蓄電量または蓄電量の代替値が、使用可能な蓄電量の範囲の中央のときに補正係数を１に設定し、かつ、蓄電量が増加するとともに大きくなるように設定するので、蓄電部の蓄電量不足や満充電状態になるのを防止できる。
【０００９】
本発明の請求項５に記載の発明は、請求項２ないし４に記載の分散電源システムの制御方法であって、蓄電量または蓄電量の代替値は、予め設定された期間の移動平均値を用いることを特徴としており、これにより次のような作用を有する。すなわち、蓄電量または蓄電量の代替値は、予め設定された期間の移動平均値を用いるので、請求項２ないし４に記載の作用に加えて、平均的な蓄電量の変化が把握できる。
【００１０】
本発明の請求項６に記載の発明は、請求項２ないし５に記載の分散電源システムの制御方法であって、分散電源システムの出力電圧を検出し、分散電源システムに予め設定された過電圧保護レベルの電圧値よりも小さな基準保護電圧値を予め設定しておき、分散電源システムの出力電圧が基準保護電圧値に達すると、出力電圧が過電圧保護レベルの電圧値を越えないように、電力系統側への出力目標値を予め設定された割合で下方に補正して、新たな出力目標値とすることを特徴としており、これにより次のような作用を有する。すなわち、分散電源システムの出力電圧を検出し、分散電源システムに予め設定された過電圧保護レベルの電圧値よりも小さな基準保護電圧値を予め設定しておき、分散電源システムの出力電圧が基準保護電圧値に達すると、出力電圧が過電圧保護レベルの電圧値を越えないように、電力系統側への出力目標値を予め設定された割合で下方に補正して、新たな出力目標値とするので、請求項２ないし５の作用に加えて、過電圧保護による分散電源システムの急激な停止を防止できる。
【００１１】
本発明の請求項７に記載の発明は、請求項２ないし６に記載の分散電源システムの制御方法であって、分散電源が太陽光発電装置であり、電力変動平滑化装置の電力系統側に直流電力を交流電力に変換する電力変換装置を備え、電力変換装置が、電力変動平滑化装置の接続点よりも太陽光発電装置側の出力に基づいて最大電力点追従制御を行うことを特徴としており、これにより次のような作用を有する。すなわち、分散電源が太陽光発電装置であり、電力変動平滑化装置の電力系統側に直流電力を交流電力に変換する電力変換装置を備え、電力変換装置が、電力変動平滑化装置の接続点よりも太陽光発電装置側の出力に基づいて最大電力点追従制御を行うので、請求項２ないし６に記載の作用に加えて、太陽電池から有効に電力を取り出すことができる。
【００１２】
本発明の請求項８に記載の発明は、請求項７に記載の分散電源システムの制御方法であって、出力目標値がゼロのとき、電力変換装置を停止させ、電力変動平滑化装置により、最大電力点追跡制御を行うことを特徴としており、これにより次のような作用を有する。すなわち、出力目標値がゼロのとき、電力変換装置を停止させ、電力変動平滑化装置により、最大電力点追跡制御を行うので、請求項７に記載の作用に加えて、電力変換装置の不安定動作を防止できるとともに電力変換装置内の損失を発生させない。
【００１３】
本発明の請求項９に記載の発明は、請求項７または８に記載の分散電源システムの制御方法であって、電力変換装置が停止したとき、出力目標値をゼロにすることを特徴としており、これにより次のような作用を有する。すなわち、電力変換装置が停止したとき、出力目標値をゼロにするので、請求項７または８に記載の作用に加えて、電力変換装置の停止時に発生する電力変換装置入力側の過電圧を防止する。
【００１４】
【発明の実施の形態】
以下、本発明の実施の形態を図面を参照して詳細に説明する。
図１は、本発明の制御方法を実施するため電力変動平滑化装置を備えた分散電源システムの実施形態を示す構成図である。ここで、分散電源９は、風力発電装置や太陽光発電装置のような電力変動の激しい電源であり、以下の説明では太陽光発電装置の場合を例に説明する。分散電源システム１０は、分散電源９、逆流防止用ダイオード１４、電力変動平滑化装置１及び系統連系型の電力変換装置１５とからなり、系統連系用変圧器１１を介して電源１３の電力系統１２に接続されている。ここで、電源１３は、電力会社の発電所の電源であってもよいし、離島などでのディーゼル発電機のような小規模の独立電源であってもよいし、需要家の自家用発電装置であってもよい。
【００１５】
電力変動平滑化装置１は、電力を蓄える蓄電部２と電力変動を平滑化するための電力調整を行う充放電部３と制御部４とからなり、分散電源９と電力変換装置１５の間に設けられている。
電力変換装置１５は分散電源９からの直流電力を交流電力に変換する装置であり、最大電力点追跡制御機能や力率１制御機能及び各種保護機能を有する系統連系型の太陽光発電用インバータを用いることができる。ただし、市販の太陽光発電用インバータをそのまま接続すると、最大点追跡制御を行うための入力信号を電力変動平滑化装置１の出力側からとることになり、電力変動平滑化装置１の制御と電力変換装置１５の最大点追跡制御が干渉して良好な制御ができない。電力変動平滑化装置１を良好に動作させ、かつ、電力変換装置１５の最大点追跡制御を良好に行うためには、図１に示すように分散電源９の出力の検出点を電力変動平滑化装置１の接続点Ａより分散電源９側にする必要がある。
また、系統連系用変圧器１１は、電力変換装置１５の出力電圧を電力系統１２の電圧に合わせるために必要に応じて設けられるものであり、連系される電力系統１２が低圧であり、電力変換装置１５の出力電圧が系統１２の電圧と一致している場合は省略することもできる。
蓄電部２は、電気二重層コンデンサや、鉛蓄電池、レドックスフロー電池、ナトリウム硫黄電池、亜鉛臭素電池、リチウムイオン電池などの二次電池や、フライホイール及び超電導コイルなどであり、電力を蓄えるものであればよい。
充放電部３は、制御部４からの指令にしたがって蓄電部２に充電したり、蓄電部２に蓄えられた電力を放電して、双方向に電力変動を平滑化するための電力ΔＰ'を調整して出力する機能を有している。図１において、分散電源９の出力Ｐと電力系統側への出力Ｐ’と電力変動平滑化装置１の出力ΔＰ'の関係は、Ｐ’＝Ｐ＋ΔＰ'である。
制御部４は、少なくとも分散電源９の出力Ｐを検出する出力検出部５と、蓄電部２の蓄電量を検出する蓄電量検出部６と、電力系統側への出力目標値Ｐ0'を設定する目標値設定部７と、電力系統側への出力Ｐ’が出力目標値Ｐ0'になるように充放電部３を制御する充放電制御部８とからなっており、電力変動平滑化装置１の動作全体を制御するものである。
出力検出部５は、分散電源９の出力電圧と出力電流を検出することにより、出力電力を算出している。蓄電量検出部６は、蓄電部２の蓄電量を知ることができる情報から蓄電部２の蓄電量を求める機能を有している。
目標値設定部７は、ある時点において出力検出部５から得られる分散電源９の予め設定された過去の期間の出力データを用いて移動平均値を求め、その時点の蓄電量検出部６から得られる蓄電部２の蓄電量に応じて予め設定された調整値または補正係数によりその移動平均値に、補正を加えて電力変動平滑化装置１の出力目標値Ｐ0'とする機能を有している。ここで、調整値を用いる場合は移動平均値に加減算し、補正係数を用いる場合は移動平均値に補正係数を掛けることによって出力目標値Ｐ0'を設定する。
充放電制御部８は、目標値設定部７で設定された出力目標値Ｐ0'と分散電源９の出力Ｐとを比較し、電力変動平滑化装置１の出力指令値ΔＰ0'を演算し、この出力指令値ΔＰ0'どおりに電力変動平滑化装置１の出力ΔＰ'を出力するように充放電部３を制御する機能を有している。出力指令値ΔＰ0'どおりにより精度良く出力されるように、図１に示すように電力変動平滑化装置１の出力ΔＰ'を充放電制御部８にフィードバックして制御することが好ましいが、フィードバックしなくても概略制御は可能である。また、図２に示すように充放電制御部８において、目標値設定部７で設定された出力目標値Ｐ0'に電力系統側への出力Ｐ’をフィードバックすることでも、精度よく制御することができる。この場合、出力目標値Ｐ0'と分散電源９の出力Ｐとを比較する必要はない。
【００１６】
蓄電量検出部６における蓄電部２の蓄電量の検出方法については、例えば蓄電部２として電気２重層コンデンサや２次電池を用いた場合、使用した電気２重層コンデンサまたは２次電池の充放電特性、内部抵抗を予め測定しておき、蓄電量検出部６で電気２重層コンデンサまたは２次電池の端子電圧及び電流を測定することにより起電力を算出し、充放電特性から電気２重層コンデンサまたは２次電池の蓄電量を求めることができる。その他、充電時と放電時のそれぞれの「kWh」を計算しておき、蓄電部２や充放電部３などの損失などを考慮して蓄電量を求めるなど、従来の種々の検出方法を用いることができる。また、ここで用いられる蓄電量の値は、蓄電量検出部６で検出される瞬時値を用いてもよいし、予め設定された時間の移動平均値を求めて用いてもよい。蓄電量の移動平均値は、蓄電量検出部６で演算されてもよいし、目標値設定部７で演算されてもよい。さらに、蓄電量の代わりに蓄電量を反映している端子電圧などの代替値を用いることも可能である。
【００１７】
次に、本発明の分散電源システムの動作について、図３ないし図５を用いて説明する。
電力変動平滑化装置１の出力の目標値の基準は、従来例と同様に分散電源９の出力Ｐの予め設定された期間の移動平均値であり、移動平均を求める期間が重要となる。移動平均を求める期間によって平滑化できる変動成分の大きさが異なる。すなわち、移動平均を求める期間が短すぎると蓄電部２の必要容量を小さくできるが、問題とする電力変動を平滑できないおそれがあり、逆に移動平均を求める期間が長すぎると、平滑度は上がるが蓄電部２の必要容量が大きくなり、設置面積やコスト面で問題となるおそれがある。例えば、電源１３の発電機のガバナー制御の応答性や電力系統１２に設けられている電圧調整器（ＳＶＲ）などの応答性などを考慮してそれら既設の電力変動平滑化手段では対応できない速い変動のみを対象にし、既設の電力変動平滑化手段と協調をとるように動作させることが蓄電部２の必要容量を小さくできるので好ましい。
以上のように移動平均を求める期間は、分散電源の種類、電力変動の状態や要求される電力変動平滑効果などの関係から実験的あるいは理論的に最適な値を設定すればよい。
【００１８】
図３に予め設定された蓄電部２の蓄電量と補正係数の例を示している。ある時点において、分散電源９の過去の期間、例えば10秒間の出力データを用いて移動平均値を求める。その移動平均値に図３に示す蓄電量に応じた補正係数を掛けて出力目標値Ｐ0'とし、分散電源９の出力Ｐと比較して、分散電源９の出力Ｐの方が出力目標値Ｐ0'よりも大きいときは、出力目標値Ｐ0'と等しい分を電力系統１２側に送り出すとともに余剰分を充放電部３を介して蓄電部２に充電し、分散電源９の出力Ｐの方が出力目標値Ｐ0'よりも小さいときは、分散電源９の出力Ｐを全て電力系統１２側に送り出すとともに不足分を充放電部３を介して蓄電部２から放電して、電力変動平滑化装置１の出力Ｐ’が設定された出力目標値Ｐ0'となるように充放電部３を制御する。
図３に示すように、ある時点の蓄電部２の蓄電量がゼロからa(%)の間にあるとき、補正係数はゼロで、出力目標値Ｐ0'は移動平均値にかかわらず、ゼロとなり、電力系統１２側へは出力せず、分散電源９で発電した電力は全て蓄電部２に蓄えられる。充電が進んで蓄電量がa(%)からb(%)の間では、補正係数をゼロから１まで直線的に設定している。出力目標値Ｐ0'は蓄電量が大きくなるに従い、大きくなり、b(%)の点で移動平均値そのものに一致する。b(%)からc(%)の間で補正係数は１に設定されている。この間の出力目標値Ｐ0'は各時点での移動平均値となる。充電割合が多くて蓄電量がさらに大きくなり、c(%)を越えると補正係数をＡまで直線的に大きくなるように設定する。ｄ(%)から１００(%)の間では補正係数はＡに設定され、出力目標値は各時点での移動平均値のＡ倍となる。Ａの値は、電力変動の大きさ、蓄電容量などを考慮して設定される。ただし、出力目標値Ｐ0'は移動平均値に補正係数を掛けた値であるが、その値が分散電源９の最大出力を越える場合は、最大出力を出力目標値Ｐ0'とする。この例のように蓄電量の下限値をb(%)、上限値をc(%)として、下限値を下回ると補正係数が１より小さくなり、すなわち出力目標値Ｐ0'が分散電源９の出力Ｐの移動平均値より小さく設定されるため、充電割合が増加し、逆に上限値を超えると補正係数は１より大きくなり、すなわち出力目標値Ｐ0'が分散電源９の出力Ｐの移動平均値よりも大きく設定されるために放電割合が増加することにより、蓄電部２の蓄電量不足や満充電状態を防ぐことができる。
【００１９】
図４に予め設定された蓄電部２の蓄電量（蓄電部の端子電圧）と補正係数の関係の他の例を示す。図４において、縦軸は補正係数であり、横軸は蓄電量に対応する蓄電部２の端子電圧であり、蓄電量を端子電圧で代替した例である。また、端子電圧は瞬時値を用いてもよいが、ここでは予め設定された期間の移動平均値を用いる例を示す。図４において蓄電部２の充放電可能な蓄電量に相当する端子電圧の範囲の中央であるy(V)のときに補正係数が１になるように、その前後でx(V)からz(V)まで右上がりの二次曲線で補正係数が設定されている。x(V)以下では、補正係数がゼロで出力目標値Ｐ0'はゼロとなる。また、z(V)以上では分散電源９の最大出力値を出力目標値Ｐ0'とするように設定している。このように設定することにより、端子電圧(蓄電量)の移動平均値がy(V)より大きくなると出力目標値が分散電源９の出力Ｐの移動平均値よりも大きく設定され、放電割合が増加し、また、逆に端子電圧(蓄電量)の移動平均値がy(V)より小さくなると出力目標値Ｐ0'が分散電源９の出力Ｐの移動平均値よりも小さく設定され、充電割合が増加するため、端子電圧(蓄電量)の移動平均値はほぼ中央値y(V)付近に制御され、蓄電部２の蓄電量不足や満充電状態を防ぐことができる。
上記の２つの例は蓄電量と補正係数の関係の一例であり、蓄電部２の種類や電力変動の大きさなどによって最適になるように設定すればよい。
【００２０】
図５に分散電源９の出力Ｐと出力目標値Ｐ0'との比較による充放電動作例及び電力変動平滑化の例を示す。分散電源９の出力Ｐが出力目標値Ｐ0'を上回るとき、上回った部分（ハッチング部分）は蓄電部２に充電され、出力目標値Ｐ0'を下回ったときは不足部分を蓄電部２から放電して出力目標値Ｐ0'に合うように出力制御され、電力変動が平滑化されている。
次に、分散電源システムがある特別な状態になったときの動作について説明する。分散電源システムが電力系統に連系される場合、種々の保護を行うための連系保護装置が分散電源システムに設けられる。その機能の１つに過電圧保護があり、分散電源の出力により電力系統が過電圧になるのを防止する機能であり、この機能が働くと分散電源システムは遮断される。なお、過電圧保護レベルは、電圧値と時限とを予め連系保護装置に設定できるようになっている。分散電源システムが上記のように出力目標値に従って出力しているときに過電圧保護が働くと出力が急にゼロとなるため、この出力変動が電力系統に悪影響を及ぼす可能性もある。そこで、図６に示すように分散電源システム１０の出力側の電圧を検出して出力目標設定部７に入力し、その電圧が分散電源システムに含まれる、図示していない系統連系保護装置に予め設定された過電圧保護レベルの電圧値よりも小さな基準保護電圧値を出力目標設定部７に予め設定しておき、分散電源システムの出力電圧が基準保護電圧値に達すると、出力目標設定部７において、分散電源９の出力の移動平均値と蓄電部２の蓄電量とから設定される出力目標値を予め設定された割合で下方に調整して出力目標値Ｐ0'を再設定し、出力電圧が過電圧にならないように分散電源システム１０の出力電力を減少させることで、分散電源システム１０の急な停止による電力変動を防止することができる。分散電源９の出力は、過電圧保護により分散電源システムが停止しないレベルで電力系統１２に出力変動を抑制した電力が供給され、残りは蓄電部２に充電することができる。
【００２１】
上記実施の形態の説明では、分散電源９が太陽光発電装置の場合で、電力変動平滑化装置１が分散電源９と電力変換装置１５との間の直流部分で接続されている例を用いて説明したが、図７に示すように電力変換装置１５の後の交流部分に接続しても良い。また、風力発電装置のような交流電力を出力する分散電源の場合は、図７において太陽光発電装置を風力発電装置に代え、逆流防止用ダイオード１４や電力変換装置１５なしで、交流部分に電力変動平滑化装置１を接続し、電力系統１２に接続される。これらについても上記の同様な動作で分散電源９による電力変動を平滑することができる。
また、分散電源９が、太陽光発電装置の場合であって、電力変換装置１５と電力変動平滑化装置１とを組み合わせて使用する場合において、電力変換装置１５と電力変動平滑化装置１の各々が独立して制御を行うと整合性が悪く、分散電源システム１０として安定した動作が得られないおそれがある。例えば、分散電源９から最大電力を取り出すために電力変換装置１５は最大電力点追跡制御機能を有している。前述したように、電力変動平滑化装置１にそのまま市販の電力変換装置１５を接続するとお互いの制御が干渉して良好な動作が行えない。電力変動平滑化装置１の制御と電力変換装置１５の最大電力点追跡制御との干渉を防止して、電力変動平滑化装置１を良好に動作させ、かつ、電力変換装置１５の最大点追跡制御を良好に行うために、図１に示すように分散電源９の出力の検出点を電力変動平滑化装置１の接続点Ａより分散電源９側にする必要がある。
また、分散電源システム１０の起動時に蓄電部２の蓄電量が予め設定された必要量より少ない場合には、電力変動平滑化装置１の出力目標値はゼロとなるが、その際には電力変換装置１５は停止しておき、電力変動平滑化装置１が分散電源９の最大電力点追跡制御または定電圧制御により蓄電部２を必要な蓄電量まで充電する。電力変換装置１５を停止しておくことにより、電力変換装置１５の不要なポンピングを防止し、電力変換装置１５の固定損を発生させず、高効率運転が可能となる。蓄電部２が充分蓄電されていれば、電力変換装置１５へ運転指令を出力して電力変換装置１５の動作を確認する。このとき、電力変換装置１５が動作していれば、電力変動平滑化装置１は出力目標値Ｐ0'を出力するように動作する。もし、電力変換装置１５が動作していなければ動作するまで待機する。
さらに、電力系統１２の異常または電力変換装置１５の異常により電力変換装置１５が前述の保護機能などの働きで停止した場合に、電力変動平滑化装置１５がそれまでの出力目標値Ｐ0'をそのまま出し続けると電力変動平滑化装置１の出力側即ち電力変換装置１５の入力側で過電圧が発生し、機器を破損するおそれがある。そこで、電力変動平滑化装置１は、電力変換装置１５の停止を確認して、出力目標値をゼロに変更して、分散電源９の出力を全て蓄電部２に充電するように制御する。蓄電部２が満充電になった場合は、電力変動平滑装置１を停止させる。また、電力変換装置１５が再び、運転開始した場合、それを検知して電力変動平滑化装置１は、上記の通常の動作を行う。このように電力変動平滑化装置１は、蓄電部２の蓄電量と電力変換装置１５の運転状態を監視することで各々の制御の整合性をとり、分散電源システムを良好に動作させることが可能となる。
本実施の形態の制御方法を用いると蓄電量が少なくなってくると出力目標値Ｐ0'を減少させて充電量を多くし、蓄電量が多くなると出力目標値Ｐ0'を大きくして放電量を多くすることにより、蓄電部２の満充電状態や放電終止状態を起こすことがないので、電力変動平滑化装置１を有する分散電源システムは常に分散電源９による電力変動を平滑化することができる。また、分散電源９の出力の移動平均値を中心に充電、放電を繰り返し、それに必要なだけの蓄電容量を準備すればよいので、蓄電部２の容量を低減することが可能であり、コンパクト化及び低コスト化できる。
【００２２】
【発明の効果】
以上のように本発明によれば、次のような効果を有する。
請求項１によれば、制御部が分散電源の出力を検出する出力検出部と、蓄電部の蓄電量を検出する蓄電量検出部と、分散電源の出力の予め設定された期間の移動平均値を、蓄電量または蓄電量の代替値に応じて、予め設定された調整値または補正係数で補正して、電力系統側への出力目標値を設定する目標値設定部と、分散電源の出力と出力目標値とを比較して、または電力系統側への出力をフィードバックして電力系統側への出力が出力目標値になるように充放電部を制御する充放電制御部とを備えているので、蓄電部の蓄電量不足や満充電状態になるのを防止して確実に出力変動を抑制できるとともに、分散電源の出力の移動平均値を中心に充電、放電を繰り返し、それに必要なだけの蓄電容量を準備すればよいので、蓄電部の容量を低減することが可能であり、電力変動平滑化装置をコンパクト化及び低コスト化できる。
【００２３】
請求項２によれば、分散電源の出力と蓄電部の蓄電量を検出し、分散電源の出力の予め設定された期間の移動平均値を求め、蓄電量または蓄電量の代替値に応じて、予め設定された調整値または補正係数で移動平均値を補正して、出力目標値を設定し、分散電源の出力が出力目標値よりも大きいときは、その余剰分を蓄電部に充電し、分散電源の出力が出力目標値よりも小さいときは、その不足分を蓄電部から放電して、電力系統側への出力が出力目標値になるように制御するので、蓄電部の蓄電量不足や満充電状態になるのを確実に防止して電力系統への悪影響を防止できるとともに、分散電源の出力の移動平均値を中心に充電、放電を繰り返し、それに必要なだけの蓄電容量を準備すればよいので、蓄電部の容量を低減することが可能であり、電力変動平滑化装置をコンパクト化及び低コスト化できる。
【００２４】
請求項３によれば、蓄電量または蓄電量の代替値の上限値と下限値を予め設定し、蓄電量または蓄電量の代替値が上限値より大きいときは、出力目標値が移動平均値よりも大きくなるように調整値または補正係数を設定し、蓄電量または蓄電量の代替値が上限値と下限値の間にあるときは、調整値をゼロに設定するか、または補正係数を１に設定し、蓄電または蓄電量の代替値量が下限値より小さいときは、出力目標値が移動平均値よりも小さくなるように調整値または補正係数を設定するので、蓄電部の蓄電量不足や満充電状態になるのを防止して電力系統への悪影響を防止できる。
【００２５】
請求項４によれば、蓄電部の使用可能な蓄電量の範囲内に下限値を予め設定し、蓄電量または蓄電量の代替値が、下限値よりも小さいときは、補正係数をゼロに設定し、蓄電量または蓄電量の代替値が、使用可能な蓄電量の範囲の中央のときに補正係数を１に設定し、かつ、蓄電量または蓄電量の代替値が増加するとともに大きくなるように設定するので、蓄電部の蓄電量不足や満充電状態になるのを防止して電力系統への悪影響を防止できる。
【００２６】
請求項５によれば、蓄電量の値として、予め設定された期間の移動平均値を用いるので、請求項２ないし４に記載の効果に加えて、より小容量で出力変動を抑制できる。また、出力変動を抑制するために蓄電部を充放電した蓄電量の変動の影響を少なくできる。
【００２７】
請求項６によれば、分散電源システムの出力電圧を検出し、分散電源システムに予め設定された過電圧保護レベルの電圧値よりも小さな基準保護電圧値を予め設定しておき、分散電源システムの出力電圧が基準保護電圧値に達すると、出力電圧が過電圧保護レベルの電圧値を越えないように、電力系統側への出力目標値を予め設定された割合で下方に補正して、新たな出力目標値とするので、請求項２ないし５の効果に加えて、過電圧保護による分散電源システムの急激な停止を防止して、これによる電力系統への悪影響を防止できる。
【００２８】
請求項７によれば、分散電源が太陽光発電装置であり、電力変動平滑化装置の電力系統側に直流電力を交流電力に変換する電力変換装置を備え、電力変換装置が、電力変動平滑化装置の接続点よりも太陽光発電装置側の出力に基づいて最大電力点追従制御を行うので、請求項２ないし６に記載の効果に加えて、太陽電池から有効に電力を取り出すことができる。
【００２９】
請求項８によれば、出力目標値がゼロのとき、電力変換装置を停止させ、電力変動平滑化装置により、最大電力点追跡制御を行うので、請求項７に記載の効果に加えて、電力変換装置の不安定動作を防止できるとともに電力変換装置内の損失を発生させず、安定した高効率なシステムを提供できる。
【００３０】
請求項９によれば、電力変換装置が停止したとき、出力目標値をゼロにするので、請求項７または８に記載の効果に加えて、電力変換装置の停止時に発生する電力変換装置入力側の過電圧による機器の破損を防止できる。
【図面の簡単な説明】
【図１】本発明の制御方法を実施するための電力変動平滑化装置を備えた分散電源システムの実施の形態を示す構成図である。
【図２】本発明に係る分散電源システムの制御方法の実施の形態の他の例を示す構成図である。
【図３】本発明に係る実施の形態における蓄電量と補正係数との関係を説明する図である。
【図４】本発明に係る実施の形態における蓄電量と補正係数の関係の他の例を説明する図である。
【図５】本発明に係る分散電源システムの実施の形態における充放電特性を説明する図である。
【図６】本発明に係る分散電源システムの実施の形態のさらに他の例を示す構成図である。
【図７】本発明に係る分散電源システムの実施の形態のさらに異なる他の例を示す構成図である。
【図８】従来の電力変動平滑化装置及びそれを備えた分散電源システムの構成図である。
【符号の説明】
１ 電力変動平滑化装置
２ 蓄電部
３ 充放電部
４ 制御部
５ 出力検出部
６ 蓄電量検出部
７ 目標値設定部
８ 充放電制御部
９ 分散電源
１０ 分散電源システム
１１ 系統連系用変圧器
１２ 電力系統
１３ 電源
１４ 逆流防止用ダイオード
１５ 電力変換装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power fluctuation smoothing device that smoothes power fluctuations caused by a distributed power source such as a wind power generation device or a solar power generation device, and a control method for a distributed power supply system including the same.
[0002]
[Prior art]
In recent years, distributed power sources that use natural energy, such as wind power generators and solar power generators, have been linked to power systems due to environmental problems and the like. The output of these distributed power sources using natural energy is unstable, and this power fluctuation causes voltage fluctuations and frequency fluctuations of the connected power system, which may adversely affect the load connected to the power system. A conventional power fluctuation smoothing apparatus and a distributed power supply system including the same, which are proposed as a countermeasure for smoothing power fluctuation when a photovoltaic power generation apparatus is used as a distributed power supply, will be described below. In FIG. 8, the distributed power supply system 10 includes a distributed power supply 9, a power fluctuation smoothing device 1 for smoothing power fluctuation caused by the distributed power supply 9, and a power converter 15 that converts DC power into AC power. And connected to the power system 12 of the power supply 13. The power fluctuation smoothing device 1 charges the power storage unit 2 that stores the generated power of the distributed power source 9 and the output of the distributed power source 9 to the power storage unit 2 or discharges the power stored in the power storage unit 2 to the power system 12 side. The charging / discharging part 3 to perform, and the control part 4 which controls the electric power fluctuation smoothing apparatus 1 whole are comprised. The control unit 4 includes an output detection unit 5 that detects the output of the distributed power source 9, a target value setting unit 7 that obtains a moving average value within a unit time of the output of the distributed power source 9 obtained from the output detection unit 5, and a target value The charging / discharging control part 8 which operates the charging / discharging part 3 based on the signal from the setting part 7 is comprised. The distributed power supply system 10 having the above configuration measures the output of the distributed power supply 9 to obtain a moving average value of the output of the distributed power supply 9 within a unit time, and the generated power of the distributed power supply 9 exceeds the moving average value. When the power storage unit 2 is charged with the surplus, and the generated power of the distributed power source 9 falls below the moving average value, the shortage is discharged from the power storage unit 2 to smooth the power fluctuation caused by the distributed power source 9. ing.
[0003]
[Problems to be solved by the invention]
However, in this system, it is assumed that the charge amount and the discharge amount are equal on average by setting the moving average value of the output of the distributed power source 9 within the unit time to the target value. When the power storage unit 2, the charge / discharge unit 3 and the like are lost, the average energy stored in the power storage unit 2 gradually decreases and the power storage amount becomes insufficient. Since the shortage from the target value, which is a value, cannot be supplied, there may occur a case where power fluctuation cannot be suppressed. On the contrary, when the amount exceeding the moving average value is larger than the amount below, the power stored in the power storage unit 2 gradually increases, and when the power storage unit 2 is fully charged, the output of the distributed power source 9 is the moving average. Even if the value exceeds the value, the power storage unit 2 cannot be charged with the surplus, and thus there is a possibility that the power fluctuation cannot be suppressed.
[0004]
The present invention prevents power from being stored in a power storage unit shortage or full charge, and reliably smoothes output fluctuations to a power system by a distributed power source such as a wind power generator or a solar power generator. It is an object to provide a fluctuation smoothing device.
Another object of the present invention is to provide a method for controlling a distributed power supply system including the power fluctuation smoothing device.
[0005]
[Means for Solving the Problems]
The present invention solves the above-described problems by the following means.
The invention according to claim 1 of the present invention includes a power storage unit, a charge / discharge unit, and a control unit. In the power fluctuation smoothing device connected to the power system together with the distributed power source, the control unit detects the output of the distributed power source. An output detection unit that detects power storage amount of the power storage unit, and a moving average value of the output of the distributed power source for a preset period according to the storage amount or an alternative value of the power storage amount The target value setting unit that sets the output target value to the power system side by correcting with the adjusted value or correction factor, and the output of the distributed power source and the output target value are compared, or the output to the power system side And a charging / discharging control unit that controls the charging / discharging unit so that the output to the power system side becomes an output target value, and has the following effects. That is, the control unit detects an output detection unit that detects the output of the distributed power source, a power storage amount detection unit that detects the power storage amount of the power storage unit, and a moving average value of the output of the distributed power source for a preset period. Alternatively, a target value setting unit that sets an output target value to the power system by correcting with a preset adjustment value or correction coefficient according to an alternative value of the storage amount, and an output of the distributed power source and an output target value Or a charge / discharge control unit that controls the charge / discharge unit so that the output to the power system side becomes the output target value by feeding back the output to the power system side. It is possible to prevent the amount of power storage from being insufficient or being fully charged.
[0006]
The invention according to claim 2 of the present invention includes a distributed power source, a power storage unit, a charge / discharge unit, and a control unit, and the control unit detects an output of the distributed power source, and detects a power storage amount of the power storage unit. The power system is configured by correcting the power storage amount detection unit and the moving average value of the output of the distributed power source for a preset period with a preset adjustment value or correction coefficient according to the storage amount or the alternative value of the storage amount. The target value setting unit that sets the output target value to the power supply side and the output of the distributed power source and the output target value are compared, or the output to the power system side is fed back and the output to the power system side is the output target value In the control method of the distributed power supply system connected to the power system, the output of the distributed power supply and the power storage of the power storage unit are provided with a power fluctuation smoothing device including a charge / discharge control unit that controls the charge / discharge unit to Detecting the amount and presetting of the output of the distributed power supply The moving average value of the period is obtained, and the output target value is set by correcting the moving average value with a preset adjustment value or correction coefficient according to the charged amount or the alternative value of the charged amount, and the output of the distributed power source When the output target value is larger, the surplus is charged to the power storage unit, and when the output of the distributed power source is smaller than the output target value, the shortage is discharged from the power storage unit and output to the power system side. Is controlled to become an output target value, and has the following effects. That is, the output of the distributed power source and the amount of power stored in the power storage unit are detected, the moving average value of the output of the distributed power source for a preset period is obtained, and the preset adjustment is performed according to the power storage amount or the alternative value of the power storage amount. The output target value is set by correcting the moving average value with the value or the correction coefficient. When the output of the distributed power source is larger than the output target value, the surplus is charged to the power storage unit, and the output of the distributed power source is output. When it is smaller than the target value, the shortage is discharged from the power storage unit, and the output to the power system is controlled so that it becomes the output target value. Can be prevented.
[0007]
The invention according to claim 3 of the present invention is the method for controlling the distributed power supply system according to claim 2, wherein an upper limit value and a lower limit value of the storage amount or an alternative value of the storage amount are set in advance, and the storage amount Alternatively, if the stored value alternative value is greater than the upper limit value, set an adjustment value or correction coefficient so that the output target value is greater than the moving average value. If the adjustment value is set to zero or the correction coefficient is set to 1 and the storage amount or the alternative value of the storage amount is smaller than the lower limit value, the output target value is less than the moving average value. It is characterized by setting an adjustment value or a correction coefficient so as to be small, and has the following action. That is, the upper limit value and the lower limit value of the storage amount or the alternative value of the storage amount are set in advance, and when the storage amount or the alternative value of the storage amount is larger than the upper limit value, the output target value is larger than the moving average value. When the adjustment value or correction coefficient is set to, and the storage amount or the alternative value of the storage amount is between the upper limit value and the lower limit value, the adjustment value is set to zero or the correction coefficient is set to 1 and When the amount or the alternative value of the storage amount is smaller than the lower limit value, the adjustment value or the correction coefficient is set so that the output target value becomes smaller than the moving average value. Can be prevented.
[0008]
The invention according to claim 4 of the present invention is the method for controlling the distributed power supply system according to claim 2, wherein a lower limit value is set in advance within the range of the amount of electricity stored in the electricity storage unit, When the stored value is smaller than the lower limit value, the correction coefficient is set to zero. When the stored value or the stored value is in the middle of the range of usable stored power, the correction coefficient is set to 1. It is characterized in that it is set so as to increase as the amount of stored electricity increases, and has the following effects. That is, when the lower limit value is set in advance within the range of the storage amount that can be used by the storage unit, and the storage amount or the alternative value of the storage amount is smaller than the lower limit value, the correction coefficient is set to zero, Since the correction value is set to 1 when the alternative value of the storage amount is in the middle of the range of the storage amount that can be used, and is set to increase as the storage amount increases, Can prevent full charge.
[0009]
The invention according to claim 5 of the present invention is the control method for the distributed power supply system according to any of claims 2 to 4, wherein the storage amount or the alternative value of the storage amount is a moving average value for a preset period. It is characterized by the fact that it has the following effects. That is, since the storage amount or the alternative value of the storage amount uses a moving average value for a preset period, it is possible to grasp an average change in the storage amount in addition to the operations described in claims 2 to 4.
[0010]
According to a sixth aspect of the present invention, there is provided the distributed power supply system control method according to any one of the second to fifth aspects, wherein the output voltage of the distributed power supply system is detected and overvoltage protection preset in the distributed power supply system is provided. Set a reference protection voltage value that is smaller than the voltage value of the level in advance, and when the output voltage of the distributed power system reaches the reference protection voltage value, the power system is set so that the output voltage does not exceed the voltage value of the overvoltage protection level. The output target value to the side is corrected downward at a preset ratio to obtain a new output target value, which has the following effects. That is, the output voltage of the distributed power supply system is detected, a reference protection voltage value smaller than the voltage value of the preset overvoltage protection level is preset in the distributed power supply system, and the output voltage of the distributed power supply system is set to the reference protection voltage. When it reaches the value, the output target value to the power system side is corrected downward at a preset ratio so that the output voltage does not exceed the voltage value of the overvoltage protection level, so that it becomes a new output target value. In addition to the operation of the second to fifth aspects, it is possible to prevent a sudden stop of the distributed power supply system due to overvoltage protection.
[0011]
The invention according to claim 7 of the present invention is the method for controlling the distributed power supply system according to any one of claims 2 to 6, wherein the distributed power supply is a solar power generator, and the power fluctuation smoothing device is connected to the power system side. A power conversion device that converts DC power into AC power is provided, and the power conversion device performs maximum power point tracking control based on the output of the photovoltaic power generation device side relative to the connection point of the power fluctuation smoothing device. This has the following effects. That is, the distributed power source is a solar power generation device, and the power fluctuation smoothing device includes a power conversion device that converts DC power into AC power on the power system side, and the power conversion device is connected to the power fluctuation smoothing device from the connection point. Since the maximum power point follow-up control is performed based on the output of the solar power generation device side, in addition to the actions described in claims 2 to 6, power can be effectively extracted from the solar cell.
[0012]
The invention according to claim 8 of the present invention is the distributed power supply system control method according to claim 7, wherein when the output target value is zero, the power conversion device is stopped, and the power fluctuation smoothing device It is characterized by performing maximum power point tracking control, and has the following effects. That is, when the output target value is zero, the power conversion device is stopped, and the power fluctuation smoothing device performs the maximum power point tracking control. Operation can be prevented and loss in the power converter is not generated.
[0013]
The invention according to claim 9 of the present invention is the method for controlling a distributed power supply system according to claim 7 or 8, characterized in that when the power converter stops, the output target value is made zero. This has the following effects. That is, when the power converter is stopped, the output target value is set to zero. Therefore, in addition to the operation according to claim 7 or 8, an overvoltage on the power converter input side that occurs when the power converter is stopped is prevented. .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram showing an embodiment of a distributed power supply system provided with a power fluctuation smoothing device for carrying out the control method of the present invention. Here, the distributed power source 9 is a power source with a large power fluctuation such as a wind power generator or a solar power generator. In the following description, the case of a solar power generator will be described as an example. The distributed power supply system 10 includes a distributed power supply 9, a backflow prevention diode 14, a power fluctuation smoothing device 1, and a grid interconnection type power conversion device 15, and the power of the power supply 13 through the grid interconnection transformer 11. It is connected to the system 12. Here, the power source 13 may be a power source of a power plant of an electric power company, a small-scale independent power source such as a diesel generator on a remote island or the like, or a consumer's private power generator. There may be.
[0015]
The power fluctuation smoothing device 1 includes a power storage unit 2 that stores power, a charge / discharge unit 3 that performs power adjustment for smoothing power fluctuations, and a control unit 4, and is arranged between the distributed power supply 9 and the power conversion device 15. Is provided.
The power conversion device 15 is a device that converts DC power from the distributed power source 9 into AC power, and is a grid-connected inverter for photovoltaic power generation having a maximum power point tracking control function, a power factor 1 control function, and various protection functions. Can be used. However, if a commercially available inverter for photovoltaic power generation is connected as it is, an input signal for performing maximum point tracking control will be taken from the output side of the power fluctuation smoothing apparatus 1, and the control and power of the power fluctuation smoothing apparatus 1 will be taken. The maximum point tracking control of the conversion device 15 interferes and good control cannot be performed. In order to operate the power fluctuation smoothing device 1 satisfactorily and to perform the maximum point tracking control of the power converter 15 satisfactorily, as shown in FIG. It is necessary to be on the distributed power source 9 side from the connection point A of the apparatus 1.
Further, the grid interconnection transformer 11 is provided as necessary in order to match the output voltage of the power conversion device 15 to the voltage of the power grid 12, and the linked power grid 12 has a low voltage, If the output voltage of the power converter 15 matches the voltage of the grid 12, it can be omitted.
The power storage unit 2 is an electric double layer capacitor, a secondary battery such as a lead storage battery, a redox flow battery, a sodium sulfur battery, a zinc bromine battery, a lithium ion battery, a flywheel, a superconducting coil, etc., and stores power. I just need it.
Charging / discharging unit 3 charges power storage unit 2 in accordance with a command from control unit 4 or discharges power stored in power storage unit 2 to provide power ΔP ′ for smoothing power fluctuations in both directions. It has the function of adjusting and outputting. In FIG. 1, the relationship between the output P of the distributed power source 9, the output P ′ to the power system side, and the output ΔP ′ of the power fluctuation smoothing device 1 is P ′ = P + ΔP ′.
The control unit 4 sets at least an output detection unit 5 that detects the output P of the distributed power supply 9, a power storage amount detection unit 6 that detects the power storage amount of the power storage unit 2, and an output target value P0 ′ to the power system. The target value setting unit 7 and the charge / discharge control unit 8 that controls the charge / discharge unit 3 so that the output P ′ to the power system side becomes the output target value P0 ′. It controls the entire operation.
The output detection unit 5 calculates the output power by detecting the output voltage and output current of the distributed power source 9. The power storage amount detection unit 6 has a function of obtaining the power storage amount of the power storage unit 2 from information that can know the power storage amount of the power storage unit 2.
The target value setting unit 7 obtains a moving average value using output data of a preset past period of the distributed power source 9 obtained from the output detection unit 5 at a certain time point, and obtains it from the storage amount detection unit 6 at that time point. The moving average value is corrected by an adjustment value or a correction coefficient set in advance according to the amount of electricity stored in the electricity storage unit 2 to obtain an output target value P0 ′ of the power fluctuation smoothing device 1. . Here, the output target value P0 ′ is set by adding / subtracting to / from the moving average value when using the adjustment value, and multiplying the moving average value by the correction coefficient when using the correction coefficient.
The charge / discharge control unit 8 compares the output target value P0 ′ set by the target value setting unit 7 with the output P of the distributed power source 9, and calculates the output command value ΔP0 ′ of the power fluctuation smoothing device 1, The charge / discharge unit 3 is controlled to output the output ΔP ′ of the power fluctuation smoothing device 1 in accordance with the output command value ΔP0 ′. It is preferable to feed back and control the output ΔP ′ of the power fluctuation smoothing device 1 to the charge / discharge control unit 8 as shown in FIG. 1 so that the output command value ΔP0 ′ is output with higher accuracy. Even if it is not, rough control is possible. Further, as shown in FIG. 2, the charge / discharge control unit 8 can accurately control the output P ′ to the power system side by feeding back the output P ′ to the output target value P 0 ′ set by the target value setting unit 7. it can. In this case, it is not necessary to compare the output target value P0 ′ with the output P of the distributed power source 9.
[0016]
About the detection method of the electrical storage amount of the electrical storage part 2 in the electrical storage amount detection part 6, when an electrical double layer capacitor or a secondary battery is used as the electrical storage part 2, for example, the charge / discharge characteristics of the used electrical double layer capacitor or secondary battery The internal resistance is measured in advance, and the electromotive force is calculated by measuring the terminal voltage and current of the electric double layer capacitor or the secondary battery by the charged amount detection unit 6, and the electric double layer capacitor or 2 is calculated from the charge / discharge characteristics. The amount of electricity stored in the secondary battery can be obtained. In addition, various conventional detection methods are used, such as calculating each “kWh” during charging and discharging, and determining the amount of power storage in consideration of the loss of the power storage unit 2 and the charge / discharge unit 3. Can do. Further, as the value of the charged amount used here, an instantaneous value detected by the charged amount detecting unit 6 may be used, or a moving average value for a preset time may be obtained and used. The moving average value of the charged amount may be calculated by the charged amount detection unit 6 or may be calculated by the target value setting unit 7. Further, it is possible to use an alternative value such as a terminal voltage reflecting the charged amount instead of the charged amount.
[0017]
Next, the operation of the distributed power supply system of the present invention will be described with reference to FIGS.
The reference of the target value of the output of the power fluctuation smoothing device 1 is the moving average value of the output P of the distributed power source 9 in a preset period as in the conventional example, and the period for obtaining the moving average is important. The magnitude of the fluctuation component that can be smoothed varies depending on the period for obtaining the moving average. That is, if the period for obtaining the moving average is too short, the required capacity of the power storage unit 2 can be reduced, but there is a possibility that the power fluctuation in question cannot be smoothed. Conversely, if the period for obtaining the moving average is too long, the smoothness increases. However, the required capacity of the power storage unit 2 is increased, which may cause a problem in terms of installation area and cost. For example, considering the responsiveness of the governor control of the generator of the power supply 13 and the responsiveness of the voltage regulator (SVR) provided in the power system 12, etc., fast fluctuations that cannot be handled by the existing power fluctuation smoothing means It is preferable to operate only in such a manner as to cooperate with existing power fluctuation smoothing means because the required capacity of the power storage unit 2 can be reduced.
As described above, the period for obtaining the moving average may be set to an optimum value experimentally or theoretically from the relationship of the type of distributed power source, the state of power fluctuation, the required power fluctuation smoothing effect, and the like.
[0018]
FIG. 3 shows an example of the power storage amount and the correction coefficient set in advance in the power storage unit 2. At a certain point in time, a moving average value is obtained using output data for a past period of the distributed power source 9, for example, 10 seconds. The moving average value is multiplied by a correction coefficient corresponding to the charged amount shown in FIG. 3 to obtain an output target value P0 ′. Compared with the output P of the distributed power source 9, the output P of the distributed power source 9 is the output target value P0. When it is larger than ', the amount equal to the output target value P0' is sent to the power system 12 side, and the surplus is charged to the power storage unit 2 via the charging / discharging unit 3, and the output P of the distributed power source 9 is output. When it is smaller than the target value P0 ′, all of the output P of the distributed power source 9 is sent to the power system 12 side, and the shortage is discharged from the power storage unit 2 via the charging / discharging unit 3, and the power fluctuation smoothing device 1 The charging / discharging unit 3 is controlled so that the output P ′ becomes the set output target value P0 ′.
As shown in FIG. 3, when the amount of electricity stored in the electricity storage unit 2 at a certain time is between zero and a (%), the correction coefficient is zero, and the output target value P0 ′ is zero regardless of the moving average value. The power generated by the distributed power source 9 is not stored in the power system 12 but is stored in the power storage unit 2. The correction coefficient is set linearly from zero to 1 when the charging progresses and the amount of stored electricity is between a (%) and b (%). The output target value P0 ′ increases as the charged amount increases, and coincides with the moving average value itself at the point of b (%). The correction coefficient is set to 1 between b (%) and c (%). The output target value P0 ′ during this time is a moving average value at each time point. When the charging rate is large and the amount of power storage is further increased, and c (%) is exceeded, the correction coefficient is set to linearly increase to A. Between d (%) and 100 (%), the correction coefficient is set to A, and the output target value is A times the moving average value at each time point. The value of A is set in consideration of the magnitude of power fluctuation, the storage capacity, and the like. However, although the output target value P0 ′ is a value obtained by multiplying the moving average value by the correction coefficient, if the value exceeds the maximum output of the distributed power source 9, the maximum output is set as the output target value P0 ′. As shown in this example, assuming that the lower limit value of the charged amount is b (%) and the upper limit value is c (%), the correction coefficient becomes smaller than 1 when the lower limit value is not reached. Since it is set smaller than the moving average value of P, the charging rate increases. Conversely, when the upper limit value is exceeded, the correction coefficient becomes larger than 1, that is, the output target value P0 ′ is the moving average value of the output P of the distributed power source 9. Since the discharge rate is increased because the value is set to be larger than that, it is possible to prevent an insufficient amount of electricity stored in the electricity storage unit 2 or a fully charged state.
[0019]
FIG. 4 shows another example of the relationship between the preset power storage amount of power storage unit 2 (terminal voltage of power storage unit) and the correction coefficient. In FIG. 4, the vertical axis represents the correction coefficient, the horizontal axis represents the terminal voltage of the power storage unit 2 corresponding to the charged amount, and the charged amount is replaced with the terminal voltage. Moreover, although an instantaneous value may be used for the terminal voltage, an example in which a moving average value for a preset period is used is shown here. In FIG. 4, x (V) to z () before and after the correction coefficient become 1 when y (V) is the center of the range of the terminal voltage corresponding to the chargeable / dischargeable amount of electricity storage unit 2. The correction coefficient is set to a quadratic curve that goes up to V). Below x (V), the correction coefficient is zero and the output target value P0 ′ is zero. In addition, the maximum output value of the distributed power supply 9 is set to the output target value P0 ′ above z (V). By setting in this way, when the moving average value of the terminal voltage (charged amount) becomes larger than y (V), the output target value is set larger than the moving average value of the output P of the distributed power source 9, and the discharge rate increases. On the contrary, when the moving average value of the terminal voltage (charged amount) becomes smaller than y (V), the output target value P0 ′ is set smaller than the moving average value of the output P of the distributed power source 9, and the charging rate increases. Therefore, the moving average value of the terminal voltage (power storage amount) is controlled to be approximately in the vicinity of the median value y (V), and a shortage of the power storage amount of the power storage unit 2 and a fully charged state can be prevented.
The above two examples are examples of the relationship between the power storage amount and the correction coefficient, and may be set to be optimal depending on the type of power storage unit 2 and the magnitude of power fluctuation.
[0020]
FIG. 5 shows an example of charge / discharge operation and an example of smoothing power fluctuation by comparing the output P of the distributed power source 9 with the output target value P0 ′. When the output P of the distributed power source 9 exceeds the output target value P0 ', the portion that exceeds the value (hatched portion) is charged to the power storage unit 2, and when the output P value falls below the output target value P0', the insufficient portion is discharged from the power storage unit 2. Thus, the output is controlled so as to match the output target value P0 ′, and the power fluctuation is smoothed.
Next, the operation when the distributed power supply system enters a special state will be described. When the distributed power supply system is connected to the power system, a connection protection device for performing various protections is provided in the distributed power supply system. One of the functions is overvoltage protection, which is a function for preventing the power system from becoming overvoltage due to the output of the distributed power supply. When this function is activated, the distributed power supply system is shut off. The overvoltage protection level can set the voltage value and the time limit in advance in the interconnection protection device. If the overvoltage protection is activated when the distributed power supply system is outputting according to the output target value as described above, the output suddenly becomes zero, and this output fluctuation may adversely affect the power system. Therefore, as shown in FIG. 6, the voltage on the output side of the distributed power supply system 10 is detected and input to the output target setting unit 7, and the voltage is included in the grid interconnection protection device (not shown) included in the distributed power supply system. A reference protection voltage value smaller than a voltage value of a preset overvoltage protection level is set in advance in the output target setting unit 7, and when the output voltage of the distributed power supply system reaches the reference protection voltage value, the output target setting unit 7 , The output target value set from the moving average value of the output of the distributed power source 9 and the amount of power stored in the power storage unit 2 is adjusted downward at a preset ratio to reset the output target value P0 ′, and the output voltage By reducing the output power of the distributed power supply system 10 so that does not become an overvoltage, it is possible to prevent power fluctuation due to a sudden stop of the distributed power supply system 10. The output of the distributed power supply 9 is supplied with electric power whose output fluctuation is suppressed to the power system 12 at a level at which the distributed power supply system does not stop due to overvoltage protection, and the rest can charge the power storage unit 2.
[0021]
In the description of the above embodiment, an example in which the distributed power source 9 is a solar power generation device and the power fluctuation smoothing device 1 is connected at the direct current portion between the distributed power source 9 and the power conversion device 15 will be used. Although demonstrated, you may connect to the alternating current part after the power converter device 15 as shown in FIG. In the case of a distributed power source that outputs AC power, such as a wind power generator, the solar power generator is replaced with a wind power generator in FIG. 7, and power is supplied to the AC portion without the backflow prevention diode 14 or the power converter 15. The fluctuation smoothing device 1 is connected to the power system 12. In these cases as well, power fluctuations caused by the distributed power supply 9 can be smoothed by the same operation as described above.
In the case where the distributed power source 9 is a solar power generation device and the power conversion device 15 and the power fluctuation smoothing device 1 are used in combination, each of the power conversion device 15 and the power fluctuation smoothing device 1 is used. However, if the control is performed independently, the consistency is poor, and there is a possibility that a stable operation cannot be obtained as the distributed power supply system 10. For example, in order to extract the maximum power from the distributed power supply 9, the power converter 15 has a maximum power point tracking control function. As described above, when a commercially available power conversion device 15 is connected to the power fluctuation smoothing device 1 as it is, a mutual operation is interfered with, and a favorable operation cannot be performed. Interference between the control of the power fluctuation smoothing apparatus 1 and the maximum power point tracking control of the power conversion apparatus 15 is prevented, the power fluctuation smoothing apparatus 1 operates favorably, and the maximum point tracking control of the power conversion apparatus 15 is performed. 1, the detection point of the output of the distributed power source 9 needs to be closer to the distributed power source 9 than the connection point A of the power fluctuation smoothing device 1 as shown in FIG.
In addition, when the amount of power stored in the power storage unit 2 is smaller than a preset required amount when the distributed power supply system 10 is activated, the output target value of the power fluctuation smoothing device 1 is zero. The apparatus 15 is stopped, and the power fluctuation smoothing apparatus 1 charges the power storage unit 2 to a necessary power storage amount by maximum power point tracking control or constant voltage control of the distributed power supply 9. By stopping the power conversion device 15, unnecessary pumping of the power conversion device 15 is prevented, and high efficiency operation is possible without causing a fixed loss of the power conversion device 15. If the power storage unit 2 is sufficiently charged, an operation command is output to the power conversion device 15 to confirm the operation of the power conversion device 15. At this time, if the power conversion device 15 is operating, the power fluctuation smoothing device 1 operates to output the output target value P0 ′. If the power converter 15 is not operating, it waits until it operates.
Further, when the power conversion device 15 is stopped due to the abnormality of the power system 12 or the power conversion device 15, the power fluctuation smoothing device 15 keeps the output target value P0 ′ until then. If it continues to be output, an overvoltage is generated on the output side of the power fluctuation smoothing device 1, that is, the input side of the power conversion device 15, and the device may be damaged. Therefore, the power fluctuation smoothing apparatus 1 confirms that the power conversion apparatus 15 is stopped, changes the output target value to zero, and controls the power storage unit 2 to charge all the outputs of the distributed power supply 9. When the power storage unit 2 is fully charged, the power fluctuation smoothing device 1 is stopped. Further, when the power conversion device 15 starts operation again, this is detected, and the power fluctuation smoothing device 1 performs the normal operation described above. As described above, the power fluctuation smoothing device 1 can monitor the amount of power stored in the power storage unit 2 and the operating state of the power conversion device 15 to ensure consistency of each control and to operate the distributed power supply system satisfactorily. It becomes.
When the control method of the present embodiment is used, the output target value P0 ′ is decreased to increase the charge amount when the storage amount decreases, and the output target value P0 ′ is increased to increase the discharge amount when the storage amount increases. By increasing the number, the power storage unit 2 is not fully charged or discharged, so that the distributed power supply system having the power fluctuation smoothing device 1 can always smooth the power fluctuation caused by the distributed power supply 9. In addition, since charging and discharging are repeated centering on the moving average value of the output of the distributed power source 9, and only the necessary storage capacity is prepared, the capacity of the power storage unit 2 can be reduced, and the size can be reduced. In addition, the cost can be reduced.
[0022]
【The invention's effect】
As described above, the present invention has the following effects.
According to claim 1, the control unit detects the output of the distributed power source, the power storage amount detection unit detects the power storage amount of the power storage unit, and the moving average value of the output of the distributed power source for a preset period According to the storage amount or the alternative value of the storage amount, a target value setting unit that sets an output target value to the power system side by correcting with a preset adjustment value or correction coefficient, and an output of the distributed power source Because it has a charge / discharge control unit that controls the charge / discharge unit so that the output to the power system side becomes the output target value by comparing the output target value or feeding back the output to the power system side In addition, it is possible to prevent output accumulation shortage and full charge state, and to suppress output fluctuations reliably, and to repeatedly charge and discharge around the moving average value of the output of the distributed power source, and to store as much electricity as necessary Since it is sufficient to prepare the capacity, the capacity of the power storage unit can be reduced. It is possible to be compact and cost power fluctuation smoothing device.
[0023]
According to claim 2, the output of the distributed power source and the amount of power stored in the power storage unit are detected, the moving average value of the output of the distributed power source for a preset period is obtained, and according to the power storage amount or the alternative value of the power storage amount, Correct the moving average value with a preset adjustment value or correction coefficient, set the output target value, and when the output of the distributed power source is larger than the output target value, charge the power storage unit with the surplus and distribute When the output of the power supply is smaller than the output target value, the shortage is discharged from the power storage unit, and control is performed so that the output to the power system becomes the output target value. It is possible to reliably prevent the charging state from being adversely affected to the power system, and to repeatedly charge and discharge around the moving average value of the output of the distributed power source, and to prepare the necessary storage capacity for it. Therefore, it is possible to reduce the capacity of the power storage unit Ri, can be made compact and cost of power fluctuation smoothing device.
[0024]
According to claim 3, when the upper limit value and the lower limit value of the storage amount or the alternative value of the storage amount are set in advance, and the alternative value of the storage amount or the storage amount is larger than the upper limit value, the output target value is greater than the moving average value. The adjustment value or correction coefficient is set to be larger, and when the storage amount or the alternative value of the storage amount is between the upper limit value and the lower limit value, the adjustment value is set to zero or the correction coefficient is set to 1. When the power storage or the alternative value of the storage amount is smaller than the lower limit value, the adjustment value or correction coefficient is set so that the output target value is smaller than the moving average value. The charging state can be prevented and adverse effects on the power system can be prevented.
[0025]
According to claim 4, when the lower limit value is set in advance within the range of the amount of electricity that can be used by the electricity storage unit, and the storage amount or the alternative value of the electricity storage amount is smaller than the lower limit value, the correction coefficient is set to zero. The correction amount is set to 1 when the storage amount or the substitution value of the storage amount is in the middle of the range of the usable storage amount, and increases as the storage amount or the substitution value of the storage amount increases. Since the setting is made, it is possible to prevent the power storage unit from being insufficiently charged or being fully charged, thereby preventing adverse effects on the power system.
[0026]
According to the fifth aspect, since the moving average value for a preset period is used as the value of the charged amount, the output fluctuation can be suppressed with a smaller capacity in addition to the effects of the second to fourth aspects. Moreover, the influence of the fluctuation | variation of the electrical storage amount which charged / discharged the electrical storage part in order to suppress an output fluctuation | variation can be decreased.
[0027]
According to claim 6, the output voltage of the distributed power supply system is detected, a reference protection voltage value smaller than the voltage value of the overvoltage protection level preset in the distributed power supply system is set in advance, and the output of the distributed power supply system is set. When the voltage reaches the reference protection voltage value, the output target value to the power system is corrected downward at a preset ratio so that the output voltage does not exceed the voltage value of the overvoltage protection level, and a new output target is set. Therefore, in addition to the effects of the second to fifth aspects, it is possible to prevent an abrupt stop of the distributed power supply system due to overvoltage protection, thereby preventing an adverse effect on the power system.
[0028]
According to claim 7, the distributed power source is a photovoltaic power generation device, and the power fluctuation smoothing device includes a power conversion device that converts DC power into AC power on the power system side, and the power conversion device smoothes power fluctuation. Since the maximum power point tracking control is performed based on the output of the photovoltaic power generation device side with respect to the connection point of the device, in addition to the effects of claims 2 to 6, power can be effectively extracted from the solar cell.
[0029]
According to claim 8, when the output target value is zero, the power conversion device is stopped, and the power fluctuation smoothing device performs the maximum power point tracking control. Therefore, in addition to the effect of claim 7, An unstable operation of the converter can be prevented and a loss in the power converter can be prevented, and a stable and highly efficient system can be provided.
[0030]
According to claim 9, when the power converter stops, the output target value is set to zero. Therefore, in addition to the effect of claim 7 or 8, the power converter input side generated when the power converter stops It is possible to prevent the equipment from being damaged by overvoltage.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of a distributed power supply system including a power fluctuation smoothing device for implementing a control method of the present invention.
FIG. 2 is a configuration diagram showing another example of the embodiment of the control method of the distributed power supply system according to the present invention.
FIG. 3 is a diagram for explaining a relationship between a storage amount and a correction coefficient in the embodiment according to the present invention.
FIG. 4 is a diagram for explaining another example of the relationship between the charged amount and the correction coefficient in the embodiment according to the present invention.
FIG. 5 is a diagram for explaining charge / discharge characteristics in the embodiment of the distributed power supply system according to the present invention;
FIG. 6 is a configuration diagram showing still another example of the embodiment of the distributed power supply system according to the present invention.
FIG. 7 is a configuration diagram showing still another example of the embodiment of the distributed power supply system according to the present invention.
FIG. 8 is a configuration diagram of a conventional power fluctuation smoothing device and a distributed power supply system including the same.
[Explanation of symbols]
1 Power fluctuation smoothing device
2 Power storage unit
3 Charge / discharge section
4 Control unit
5 Output detector
6 Power storage amount detection unit
7 Target value setting section
8 Charge / Discharge Control Unit
9 Distributed power supply
10 Distributed power supply system
11 Transformer for grid connection
12 Power system
13 Power supply
14 Backflow prevention diode
15 Power converter

Claims (9)

蓄電部、充放電部及び制御部からなり、分散電源とともに電力系統に接続される電力変動平滑化装置において、
前記制御部が、前記分散電源の出力を検出する出力検出部と、
前記蓄電部の蓄電量を検出する蓄電量検出部と、
前記分散電源の出力の予め設定された期間の移動平均値を、前記蓄電量または前記蓄電量の代替値に応じて、予め設定された調整値または補正係数で補正して、前記電力系統側への出力目標値を設定する目標値設定部と、
前記分散電源の出力と前記出力目標値とを比較して、または前記電力系統側への出力をフィードバックして前記電力系統側への出力が前記出力目標値になるように前記充放電部を制御する充放電制御部とを備えたことを特徴とする電力変動平滑化装置。In the power fluctuation smoothing device that consists of a power storage unit, a charge / discharge unit, and a control unit and is connected to a power system together with a distributed power source,
The control unit detects an output of the distributed power supply; and
A power storage amount detection unit for detecting a power storage amount of the power storage unit;
The moving average value of the output of the distributed power source for a preset period is corrected with a preset adjustment value or a correction coefficient according to the storage amount or the alternative value of the storage amount, and then to the power system side. A target value setting unit for setting the output target value of
The charge / discharge unit is controlled so that the output to the power system side becomes the output target value by comparing the output of the distributed power source and the output target value or feeding back the output to the power system side A power fluctuation smoothing apparatus comprising: a charge / discharge control unit that performs 分散電源、蓄電部、充放電部及び制御部からなり、前記制御部が、前記分散電源の出力を検出する出力検出部と、前記蓄電部の蓄電量を検出する蓄電量検出部と、前記分散電源の出力の予め設定された期間の移動平均値を、前記蓄電量または前記蓄電量の代替値に応じて、予め設定された調整値または補正係数で補正して、前記電力系統側への出力目標値を設定する目標値設定部と、前記分散電源の出力と前記出力目標値とを比較して、または前記電力系統側への出力をフィードバックして前記電力系統側への出力が前記出力目標値になるように前記充放電部を制御する充放電制御部とからなる電力変動平滑化装置とを備えて、電力系統に接続される分散電源システムの制御方法において、
前記分散電源の出力と前記蓄電部の蓄電量を検出し、
前記分散電源の出力の予め設定された期間の移動平均値を求め、前記蓄電量または前記蓄電量の代替値に応じて、予め設定された調整値または補正係数で前記移動平均値を補正して前記出力目標値を設定し、
前記分散電源の出力が前記出力目標値よりも大きいときは、その余剰分を前記蓄電部に充電し、
前記分散電源の出力が前記出力目標値よりも小さいときは、その不足分を前記蓄電部から放電して、
前記電力系統側への出力が前記出力目標値になるように制御することを特徴とする分散電源システムの制御方法。A distributed power source, a power storage unit, a charge / discharge unit, and a control unit, wherein the control unit detects an output of the distributed power source, a power storage amount detection unit that detects a power storage amount of the power storage unit, and the dispersion Correct the moving average value of the output of the power source for a preset period with a preset adjustment value or correction coefficient according to the storage amount or the alternative value of the storage amount, and output to the power system side A target value setting unit for setting a target value, comparing the output of the distributed power source with the output target value, or feeding back the output to the power system side, and the output to the power system side becomes the output target In a control method for a distributed power supply system connected to an electric power system, comprising a power fluctuation smoothing device comprising a charge / discharge control unit that controls the charge / discharge unit to be a value,
Detecting the output of the distributed power source and the amount of electricity stored in the electricity storage unit;
A moving average value of the output of the distributed power source for a preset period is obtained, and the moving average value is corrected by a preset adjustment value or a correction coefficient according to the charged amount or an alternative value of the charged amount. Set the output target value,
When the output of the distributed power source is larger than the output target value, the surplus is charged to the power storage unit,
When the output of the distributed power supply is smaller than the output target value, the shortage is discharged from the power storage unit,
A control method for a distributed power supply system, wherein an output to the power system side is controlled to be the output target value. 請求項２に記載の分散電源システムの制御方法であって、
前記蓄電量または前記蓄電量の代替値の上限値と下限値とを予め設定し、
前記蓄電量または前記蓄電量の代替値が前記上限値より大きいときは、前記出力目標値が前記移動平均値よりも大きくなるように前記調整値または補正係数を設定し、
前記蓄電量または前記蓄電量の代替値が前記上限値と前記下限値の間にあるときは、前記調整値をゼロに設定するか、または前記補正係数を１に設定し、
前記蓄電量または前記蓄電量の代替値が前記下限値より小さいときは、前記出力目標値が前記移動平均値よりも小さくなるように前記調整値または補正係数を設定することを特徴とする分散電源システムの制御方法。A control method for a distributed power supply system according to claim 2,
An upper limit value and a lower limit value of the storage amount or the alternative value of the storage amount are set in advance,
When the storage amount or the alternative value of the storage amount is larger than the upper limit value, the adjustment value or the correction coefficient is set so that the output target value is larger than the moving average value,
When the charged amount or the alternative value of the charged amount is between the upper limit value and the lower limit value, the adjustment value is set to zero, or the correction coefficient is set to 1,
The distributed power source, wherein the adjustment value or the correction coefficient is set so that the output target value is smaller than the moving average value when the charged amount or an alternative value of the charged amount is smaller than the lower limit value How to control the system. 請求項２に記載の分散電源システムの制御方法であって、
前記蓄電部の使用可能な蓄電量の範囲内に下限値を予め設定し、
前記蓄電量または前記蓄電量の代替値が、前記下限値よりも小さいときは、前記補正係数をゼロに設定し、
前記蓄電量または前記蓄電量の代替値が、前記使用可能な蓄電量の範囲の中央のときに前記補正係数を１に設定し、かつ、前記蓄電量が増加するとともに大きくなるように設定することを特徴とする分散電源システムの制御方法。A control method for a distributed power supply system according to claim 2,
A lower limit is set in advance within a range of the amount of power that can be used by the power storage unit,
When the charged amount or the alternative value of the charged amount is smaller than the lower limit value, the correction coefficient is set to zero,
The correction coefficient is set to 1 when the charged amount or the alternative value of the charged amount is in the middle of the range of the usable charged amount, and is set to increase as the charged amount increases. A control method for a distributed power supply system. 請求項２ないし４に記載の分散電源システムの制御方法であって、
前記蓄電量または前記蓄電量の代替値は、予め設定された期間の移動平均値を用いることを特徴とする分散電源システムの制御方法。A control method for a distributed power supply system according to claim 2,
The control method of a distributed power system, wherein a moving average value for a preset period is used as the power storage amount or an alternative value of the power storage amount. 請求項２ないし５に記載の分散電源システムの制御方法であって、
前記分散電源システムの出力電圧を検出し、
前記分散電源システムに予め設定された過電圧保護レベルの電圧値よりも小さな基準保護電圧値を予め設定しておき、
前記分散電源システムの出力電圧が前記基準保護電圧値に達すると、前記出力電圧が前記過電圧保護レベルの電圧値を越えないように、前記電力系統側への出力目標値を予め設定された割合で下方に補正して、新たな出力目標値とすることを特徴とする分散電源システムの制御方法。A method for controlling a distributed power supply system according to claim 2,
Detecting the output voltage of the distributed power supply system;
A reference protection voltage value smaller than a voltage value of an overvoltage protection level set in advance in the distributed power supply system is set in advance,
When the output voltage of the distributed power supply system reaches the reference protection voltage value, the output target value to the power system side is set at a preset ratio so that the output voltage does not exceed the voltage value of the overvoltage protection level. A control method for a distributed power supply system, wherein the output value is corrected downward to be a new output target value. 請求項２ないし６に記載の分散電源システムの制御方法であって、
前記分散電源が太陽光発電装置であり、前記電力変動平滑化装置の前記電力系統側に直流電力を交流電力に変換する電力変換装置を備え、
前記電力変換装置が、前記電力変動平滑化装置の接続点よりも前記太陽光発電装置側の出力に基づいて最大電力点追従制御を行うことを特徴とする分散電源システムの制御方法。A method for controlling a distributed power supply system according to any one of claims 2 to 6,
The distributed power source is a photovoltaic power generation device, and includes a power conversion device that converts DC power into AC power on the power system side of the power fluctuation smoothing device,
The method for controlling a distributed power system, wherein the power conversion device performs maximum power point tracking control based on an output on a side of the photovoltaic power generation device with respect to a connection point of the power fluctuation smoothing device. 請求項７に記載の分散電源システムの制御方法であって、
前記出力目標値がゼロのとき、前記電力変換装置を停止させ、前記電力変動平滑化装置により、最大電力点追跡制御を行うことを特徴とする分散電源システムの制御方法。It is a control method of the distributed power supply system according to claim 7,
When the output target value is zero, the power conversion device is stopped, and the power fluctuation smoothing device performs maximum power point tracking control. 請求項７または８に記載の分散電源システムの制御方法であって、
前記電力変換装置が停止したとき、前記出力目標値をゼロにすることを特徴とする分散電源システムの制御方法。A control method for a distributed power supply system according to claim 7 or 8,
A control method for a distributed power supply system, wherein the output target value is set to zero when the power converter stops.
JP2000198287A 2000-06-30 2000-06-30 Power fluctuation smoothing apparatus and control method of distributed power supply system including the same Expired - Lifetime JP4170565B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000198287A JP4170565B2 (en) 2000-06-30 2000-06-30 Power fluctuation smoothing apparatus and control method of distributed power supply system including the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000198287A JP4170565B2 (en) 2000-06-30 2000-06-30 Power fluctuation smoothing apparatus and control method of distributed power supply system including the same

Publications (2)

Publication Number Publication Date
JP2002017044A JP2002017044A (en) 2002-01-18
JP4170565B2 true JP4170565B2 (en) 2008-10-22

Family

ID=18696470

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2000198287A Expired - Lifetime JP4170565B2 (en) 2000-06-30 2000-06-30 Power fluctuation smoothing apparatus and control method of distributed power supply system including the same

Country Status (1)

Country Link
JP (1) JP4170565B2 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011111475A1 (en) 2010-03-11 2011-09-15 株式会社 東芝 Solar power generation system and power supply system
CN105680485A (en) * 2014-11-18 2016-06-15 国家电网公司 Smooth output method of wind power plant
US9391537B2 (en) 2011-01-20 2016-07-12 Kabushiki Kaisha Toshiba Photovoltaic system and power supply system
US9450451B2 (en) 2010-03-12 2016-09-20 Kabushiki Kaisha Toshiba Photovoltaic generation system and power feeding system
JP2018007521A (en) * 2016-07-08 2018-01-11 株式会社Ihi Output smoothing device and output smoothing method

Families Citing this family (48)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10210099A1 (en) * 2002-03-08 2003-10-02 Aloys Wobben Stand-alone grid and method for operating a stand-alone grid
JP5354840B2 (en) * 2006-02-24 2013-11-27 沖縄電力株式会社 New energy generation system output fluctuation mitigation device
JP4715624B2 (en) * 2006-05-09 2011-07-06 富士電機システムズ株式会社 Power stabilization system, power stabilization control program, and power stabilization control method
JP4665831B2 (en) * 2006-05-24 2011-04-06 富士電機システムズ株式会社 Power stabilization system, control device, and control program thereof
JP5013372B2 (en) * 2007-09-06 2012-08-29 国立大学法人 琉球大学 Manufacturing method of storage battery equipment for wind power generator
DE102007046239A1 (en) * 2007-09-26 2009-04-02 Daubner & Stommel GbR Bau-Werk-Planung (vertretungsberechtigter Gesellschafter: Matthias Stommel, 27777 Ganderkesee) Electrical energy producing and feeding method for superordinate power supply network, involves temporarily storing part of energy in buffer, before energy is supplied to conversion device for conversion into network conformable form
JP5355907B2 (en) * 2008-02-29 2013-11-27 株式会社東芝 Power system stabilization system
JP5127513B2 (en) * 2008-03-06 2013-01-23 株式会社東芝 Output fluctuation suppression device for natural energy generator
JP5319156B2 (en) * 2008-04-24 2013-10-16 一般財団法人電力中央研究所 Power supply / demand control program, power supply / demand control apparatus, and power supply / demand control system
JP5453288B2 (en) 2008-09-30 2014-03-26 日本碍子株式会社 Control method of sodium-sulfur battery
US7768155B2 (en) * 2008-10-10 2010-08-03 Enphase Energy, Inc. Method and apparatus for improved burst mode during power conversion
WO2011078215A1 (en) * 2009-12-22 2011-06-30 三洋電機株式会社 Electric-power supply method, computer-readable recording medium, and electric-power generating system
WO2011078151A1 (en) * 2009-12-24 2011-06-30 三洋電機株式会社 Power feeding method, computer readable recording medium, and power generation system
EP2521239B1 (en) * 2009-12-28 2015-02-18 Toyota Jidosha Kabushiki Kaisha Household electricity storage system
JP5507582B2 (en) * 2010-01-27 2014-05-28 三洋電機株式会社 Power supply method, computer-readable recording medium, and power generation system
JP5475019B2 (en) * 2010-01-28 2014-04-16 三洋電機株式会社 Power supply method, computer-readable recording medium, and power generation system
JP5533343B2 (en) * 2010-06-28 2014-06-25 富士通株式会社 Electric power leveling system
CN102340150A (en) * 2010-07-20 2012-02-01 武汉瑞工科技有限公司 Electric vehicle charging station and method for charging electric vehicle
JP5165042B2 (en) * 2010-10-27 2013-03-21 中国電力株式会社 System power stabilization system, system power stabilization method, and charger / discharger
JP5664763B2 (en) * 2011-03-18 2015-02-04 富士通株式会社 Power leveling control device, power leveling power storage device, power leveling control method, and leveling program
CN103733459B (en) 2011-08-23 2016-04-06 富士通株式会社 Electric power levelized control device and electric power levelized control method
KR101139476B1 (en) 2011-10-31 2012-05-07 주식회사 동이에코스 Multi-functional electric power supplying system for totally controlling solar cell, battery and commercial power source
CN102496964B (en) * 2011-11-25 2014-11-19 北京金风科创风电设备有限公司 Method for controlling output power of microgrid
JP5839046B2 (en) * 2011-12-22 2016-01-06 富士通株式会社 Power leveling control device, power leveling control method, and program
JP6018380B2 (en) 2011-12-27 2016-11-02 川崎重工業株式会社 Grid controller for smart grid system, smart grid system including the same, and control method thereof
JP5766633B2 (en) * 2012-02-28 2015-08-19 三菱重工業株式会社 Output smoothing apparatus, output smoothing method and program
JP5738220B2 (en) * 2012-02-28 2015-06-17 三菱重工業株式会社 Output smoothing apparatus, output smoothing method and program
KR101311529B1 (en) * 2012-03-29 2013-09-25 홍선표 Power generation apparatus using current transformer
CN102684222B (en) * 2012-05-14 2014-02-19 华北电力大学 Method for smoothly controlling wind power generation power based on energy storage technology
JP5800771B2 (en) * 2012-08-10 2015-10-28 株式会社日立パワーソリューションズ Wind power generation system, wind power generation control device, and wind power generation control method
JP5940946B2 (en) * 2012-09-20 2016-06-29 京セラ株式会社 Power conditioner and control method thereof
JP5901495B2 (en) * 2012-10-26 2016-04-13 富士古河Ｅ＆Ｃ株式会社 Output stabilization controller for distributed power supply
JP5977151B2 (en) * 2012-11-16 2016-08-24 東京瓦斯株式会社 Control method, control program, and control apparatus
CN103094926B (en) * 2013-01-09 2014-12-10 清华大学 Multi-component energy-storing capacity collocation method applied to micro power grid group
WO2014199502A1 (en) * 2013-06-14 2014-12-18 株式会社 日立製作所 Power grid control device, system and method
EP3089353A4 (en) * 2013-12-27 2017-12-13 Hitachi, Ltd. Rotating electrical machine system
JP6235408B2 (en) * 2014-05-13 2017-11-22 株式会社 日立産業制御ソリューションズ Power generation system, planning device, and control method
JP6390259B2 (en) * 2014-08-13 2018-09-19 株式会社Ihi Charge / discharge control device and charge / discharge control method
JP6331998B2 (en) * 2014-12-01 2018-05-30 日本工営株式会社 Natural energy power generation system
JP6480196B2 (en) * 2015-01-26 2019-03-06 株式会社日立製作所 Storage battery system and photovoltaic power generation system having the same
JP6480198B2 (en) * 2015-01-28 2019-03-06 株式会社日立製作所 Storage battery system and photovoltaic power generation system having the same
JP6453107B2 (en) * 2015-02-25 2019-01-16 東芝三菱電機産業システム株式会社 Power generation system
CN105281371A (en) * 2015-07-03 2016-01-27 长沙理工大学 Telescopic active static safety domain taking wind power generation into account
JP6546501B2 (en) * 2015-10-16 2019-07-17 サンケン電気株式会社 Power storage device
KR101996846B1 (en) * 2018-05-23 2019-07-09 주식회사 대건소프트 Power generation tracking ESS operation system of generator of renewable energy source
JP2022187563A (en) * 2021-06-08 2022-12-20 三菱重工業株式会社 Smoothing target value calculation device, power supply system, smoothing target value calculation method, and program
JP2023069821A (en) * 2021-11-08 2023-05-18 三菱重工業株式会社 Control device, control method and charge/discharge system
CN115622136B (en) * 2022-12-16 2023-04-07 济钢防务技术有限公司 Multi-mode intelligent controller

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011111475A1 (en) 2010-03-11 2011-09-15 株式会社 東芝 Solar power generation system and power supply system
CN102714417A (en) * 2010-03-11 2012-10-03 株式会社东芝 Solar power generation system and power supply system
CN102714417B (en) * 2010-03-11 2015-02-25 株式会社东芝 Solar power generation system and power supply system
US9184626B2 (en) 2010-03-11 2015-11-10 Kabushiki Kaisha Toshiba Photovoltaic system and power supply system
US9450451B2 (en) 2010-03-12 2016-09-20 Kabushiki Kaisha Toshiba Photovoltaic generation system and power feeding system
US9391537B2 (en) 2011-01-20 2016-07-12 Kabushiki Kaisha Toshiba Photovoltaic system and power supply system
CN105680485A (en) * 2014-11-18 2016-06-15 国家电网公司 Smooth output method of wind power plant
CN105680485B (en) * 2014-11-18 2017-10-13 国家电网公司 A kind of wind power plant is smoothly exerted oneself method
JP2018007521A (en) * 2016-07-08 2018-01-11 株式会社Ihi Output smoothing device and output smoothing method

Also Published As

Publication number Publication date
JP2002017044A (en) 2002-01-18

Similar Documents

Publication Publication Date Title
JP4170565B2 (en) Power fluctuation smoothing apparatus and control method of distributed power supply system including the same
JP3352662B2 (en) Power system stabilizing apparatus and power system stabilizing method using secondary battery system
US8456878B2 (en) Power storage system and method of controlling the same
US8373312B2 (en) Solar power generation stabilization system and method
RU2565235C2 (en) Regulating contribution of secondary power supply sources to distribution network
US9153963B2 (en) Electric power control apparatus and grid connection system having same
JP2001327080A (en) Power storage device and control method of distributed power supply system equipped therewith
JP5520365B2 (en) System stabilization system, power supply system, centralized management device control method, and centralized management device program
CN110176788B (en) Power storage system and power storage device
US9148020B2 (en) Method of controlling a battery, computer readable recording medium, electric power generation system and device controlling a battery
JP2008131736A (en) Distributed power system and step-up/step-down chopper device
KR20140098431A (en) Coordinated Droop Control Apparatus and the Method for Stand-alone DC Micro-grid
US20120228941A1 (en) Electric power supply system, master control device, system stabilization system, control method for the master control device and control program for the master control device
WO2011122672A1 (en) Power supply system, power supply method, and control program for power supply system
US20170187190A1 (en) Distributed power supply system, power converter device, and method of controlling power factor
WO2011122669A1 (en) Power supply system, power supply method, and control program for power supply system
JP3781977B2 (en) Distributed power supply network
US20150263564A1 (en) Energy storage system and method for driving the same
JP2018098952A (en) Power storage system and photovoltaic power generation system
US20120253537A1 (en) Power supply method, recording medium which is computer readable and power generation system
JP4566658B2 (en) Power supply
JP5475019B2 (en) Power supply method, computer-readable recording medium, and power generation system
US10951039B2 (en) Multi-input PV inverter system and method
KR101977165B1 (en) System and method for controlling ess for emergency power source, and a recording medium having computer readable program for executing the method
JP4569223B2 (en) Power supply

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20070522

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20080728

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20080805

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20080807

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110815

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Ref document number: 4170565

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110815

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120815

Year of fee payment: 4

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130815

Year of fee payment: 5

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

EXPY Cancellation because of completion of term