JP3781977B2

JP3781977B2 - Distributed power supply network

Info

Publication number: JP3781977B2
Application number: JP2001066867A
Authority: JP
Inventors: 一彦榊原; 章竹内; 暢彦山下
Original assignee: Nippon Telegraph and Telephone Corp
Current assignee: Nippon Telegraph and Telephone Corp
Priority date: 2001-03-09
Filing date: 2001-03-09
Publication date: 2006-06-07
Anticipated expiration: 2021-03-09
Also published as: JP2002271997A

Description

【０００１】
【発明の属する技術分野】
本発明は系統保護装置を介して商用交流電力系統と連系する分散給電ネットワークに関するものである。
【０００２】
【従来の技術】
現在、商用交流電力系統と太陽電池や燃料電池等の直流発電装置を有する分散電源装置とを連係し、エネルギーの有効利用（コジェネレーションや自然エネルギーの利用など）を図ることが活発に行なわれており、この場合には分散電源装置は需要地内に設置されるから、長距離送電が不要である。このような分散給電ネットワークの検討結果は例えば「解説：電力系統技術要件ガイドライン‘９８（資源エネルギー庁編）」にまとめられており、直流発電装置は直流／交流電力変換装置を介して交流系統に接続されるように記載されている。
【０００３】
図１２は従来の分散給電ネットワークを示す図である。図に示すように、商用交流電力系統１に系統保護装置２を介して複数の交流配電線３が接続され、交流配電線３に負荷６および直流／交流電力変換装置（直流／交流インバータ）５を介して直流発電装置４が接続されている。
【０００４】
【発明が解決しようとする課題】
この分散給電ネットワークにおいては、直流発電装置４は交流配電線３に直接接続できないので、直流発電装置４は直流／交流電力変換装置５を介して交流配電線３に接続されるが、各直流発電装置４に対応して直流／交流電力変換装置５を設ける必要があるから、構成が複雑となり、多数の直流発電装置４が設けられている場合には、多数の直流／交流電力変換装置５を設ける必要があるので、設置コストが高価になる。また、直流／交流電力変換装置５を交流配電線３に接続する場合には、突入電流を防止するため、直流／交流電力変換装置５の交流出力の位相と交流配電線３の位相とを合わせ、交流出力の大きさもそろえる必要がある。仮に、直流発電装置４の出力電圧が低すぎて、交流出力の大きさを満足しない場合には、直流発電装置４に直流を昇圧する直流／直流電力変換装置を必要とする場合もある。たとえば、先ほど示した「解説：電力系統技術要件ガイドライン‘９８」には、一例として直流／交流電力変換装置における逆潮流ありの場合すなわち自家発電設備の設置者の構内から交流電力系統側へ向かう電力の流れを許す場合には、電圧上昇防止のため、受電点における力率が原則８５％以上で、交流電力系統から見て進み力率にならないことと記載されている。このように、従来の交流給電線３を有する分散給電ネットワークに直流発電装置４を接続するためには、商用交流電力系統１の従来の需要者に悪影響を与えないように厳しい制限を設ける必要がある。このため、交流給電線３に直流発電装置４を接続する場合には、直流発電装置４、直流／交流電力変換装置５を力率、位相等を考慮した構成とする必要があるから、直流発電装置４、直流／交流電力変換装置５の構成が複雑になるので、設置コストが高価になる。また、長距離の交流配電線３を引き回すので、交流配電線３から電磁波が発生し、その影響によって妨害交流電圧や電源周波数の整数倍の高調波が発生する可能性がある。
【０００５】
このように、直流発電装置４の出力電力を直流／交流電力変換装置５で変換して交流配電線３に連系する方式は、電力給電のほとんどが交流で行なわれている場合においては、有効である。しかしながら、我々の周りを見渡した場合、本当に交流電力が必要なのは回転機を使用した洗濯機、冷蔵庫、エアーコンディショナ、換気扇などに限られ、多くの電子機器が交流を直流に変換して使用している。それにも係わらず、配電線のネットワークを交流系で構成する場合には、商用交流電力系統１に悪影響を与えることがないように、個々の直流発電装置４と協調動作を取る必要があって、保護装置が多数必要になり、また交流配電線３から発生する電磁波を減少するための技術が必要になり、直流発電装置４が逆潮流を行なう場合には、直流発電装置４毎に設置される直流／交流電力変換装置５毎に逆潮流装置を設置する必要があり、構成が複雑となる。
【０００６】
本発明は上述の課題を解決するためになされたもので、商用交流電力系統に悪影響を与えることがなく、かつ構成が簡単である分散給電ネットワークを提供することを目的とする。
【０００７】
【課題を解決するための手段】
この目的を達成するため、本発明においては、系統保護装置を介して商用交流電力系統と連系する分散給電ネットワークにおいて、上記系統保護装置に直流／交流電力変換および交流／直流電力変換を行なう双方向逆変換電力装置の交流側を接続し、上記双方向逆変換電力装置の直流側に直流配電線を接続し、上記直流配電線に複数の分散電源装置と複数の負荷とを接続し、上記双方向逆変換電力装置を制御する変換制御装置を設け、上記分散電源装置の発生電力から上記負荷の消費電力を減算した余剰不足電力を検出する余剰不足電力検出装置を設け、上記変換制御装置に上記余剰不足電力検出装置により検出された余剰不足電力を積算した積算余剰不足電力を演算する演算装置を設け、上記変換制御装置に上記積算余剰不足電力に応じた動作信号を上記双方向逆変換電力装置に送出する動作信号送出装置を設ける。
【０００８】
ここで、双方向逆変換電力装置としては、直流／交流電力変換を行なう逆変換電力装置と交流／直流電力変換を行なう逆変換電力装置とが並列に接続された並列接続回路、直流／交流電力変換機能および交流／直流電力変換機能を有する逆変換電力装置等を用いることができる。
【００１０】
この場合、上記演算装置により各上記余剰不足電力から余剰電力の合計値すなわち合計余剰電力を演算し、上記合計余剰電力に基づいて各上記分散電源装置の出力電力を制御する発電制御装置を上記変換制御装置に設けてもよい。
【００１１】
また、上記分散電源装置として、直流発電装置と直流／直流電力変換装置との直列回路、充放電制御装置および蓄電装置を直列に接続したエネルギー蓄積装置と直流発電装置とを並列に接続した回路に直流／直流電力変換装置を接続した回路のいずれかを用いてもよい。
【００１２】
また、上記負荷として、直流／交流電力変換装置を介して交流負荷に交流を給電する回路、直流／直流電力変換装置を介して直流負荷に直流を給電する回路、直流／交流電力変換装置と直流／直流電力変換装置とを上記直流配電線側で並列に接続し、上記直流／交流電力変換装置を介して交流負荷に交流を給電し、かつ上記直流／直流電力変換装置を介して直流負荷に直流を給電する回路のいずれかを用いてもよい。
【００１３】
また、系統保護装置を介して商用交流電力系統と連系する分散給電ネットワークにおいて、上記系統保護装置に直流／交流電力変換および交流／直流電力変換を行なう双方向逆変換電力装置の交流側を接続し、上記双方向逆変換電力装置の直流側に直流配電線を接続し、上記直流配電線に複数の分散電源装置と複数の負荷とを接続し、上記双方向逆変換電力装置を制御する変換制御装置を設け、上記分散電源装置として直流発電装置の出力側に直列接続の充放電制御装置と蓄電装置とを並列に接続した回路を用い、上記双方向逆変換電力装置に上記商用交流電力系統から上記直流配電線に補充される補充電力を検出する補充電力検出装置を設け、上記変換制御装置に上記補充電力が所定値を越えたか否かを判断しかつ上記補充電力が所定値を越えたと判断したとき上記充放電制御装置に起動信号を出力する判断装置を設ける。
また、系統保護装置を介して商用交流電力系統と連系する分散給電ネットワークにおいて、上記系統保護装置に直流／交流電力変換および交流／直流電力変換を行なう双方向逆変換電力装置の交流側を接続し、上記双方向逆変換電力装置の直流側に直流配電線を接続し、上記直流配電線に複数の分散電源装置と複数の負荷とを接続し、上記双方向逆変換電力装置を制御する変換制御装置を設け、上記分散電源装置の発生電力から上記負荷の消費電力を減算した余剰不足電力を検出する余剰不足電力検出装置を設け、上記変換制御装置に上記余剰不足電力検出装置により検出された余剰不足電力を積算した積算余剰不足電力を演算する演算装置を設け、上記変換制御装置に上記積算余剰不足電力に応じた動作信号を上記双方向逆変換電力装置に送出する動作信号送出装置を設け、上記分散電源装置として直流発電装置の出力側に直列接続の充放電制御装置と蓄電装置とを並列に接続した回路を用い、上記双方向逆変換電力装置に上記商用交流電力系統から上記直流配電線に補充される補充電力を検出する補充電力検出装置を設け、上記変換制御装置に上記補充電力が所定値を越えたか否かを判断しかつ上記補充電力が所定値を越えたと判断したとき上記充放電制御装置に起動信号を出力する判断装置を設けてもよい。
また、系統保護装置を介して商用交流電力系統と連系する分散給電ネットワークにおいて、上記系統保護装置に直流／交流電力変換および交流／直流電力変換を行なう双方向逆変換電力装置の交流側を接続し、上記双方向逆変換電力装置の直流側に直流配電線を接続し、上記直流配電線に複数の分散電源装置と複数の負荷とを接続し、上記双方向逆変換電力装置を制御する変換制御装置を設け、上記分散電源装置の発生電力から上記負荷の消費電力を減算した余剰不足電力を検出する余剰不足電力検出装置を設け、上記変換制御装置に上記余剰不足電力検出装置により検出された余剰不足電力を積算した積算余剰不足電力を演算する演算装置を設け、上記変換制御装置に上記積算余剰不足電力に応じた動作信号を上記双方向逆変換電力装置に送出する動作信号送出装置を設け、上記演算装置により各上記余剰不足電力から余剰電力の合計値すなわち合計余剰電力を演算し、上記合計余剰電力に基づいて各上記分散電源装置の出力電力を制御する発電制御装置を上記変換制御装置に設け、上記分散電源装置として直流発電装置の出力側に直列接続の充放電制御装置と蓄電装置とを並列に接続した回路を用い、上記双方向逆変換電力装置に上記商用交流電力系統から上記直流配電線に補充される補充電力を検出する補充電力検出装置を設け、上記変換制御装置に上記補充電力が所定値を越えたか否かを判断しかつ上記補充電力が所定値を越えたと判断したとき上記充放電制御装置に起動信号を出力する判断装置を設けてもよい。
また、系統保護装置を介して商用交流電力系統と連系する分散給電ネットワークにおいて、上記系統保護装置に直流／交流電力変換および交流／直流電力変換を行なう双方向逆変換電力装置の交流側を接続し、上記双方向逆変換電力装置の直流側に直流配電線を接続し、上記直流配電線に複数の分散電源装置と複数の負荷とを接続し、上記双方向逆変換電力装置を制御する変換制御装置を設け、上記負荷として、直流／交流電力変換装置を介して交流負荷に交流を給電する回路、直流／直流電力変換装置を介して直流負荷に直流を給電する回路、直流／交流電力変換装置と直流／直流電力変換装置とを上記直流配電線側で並列に接続し、上記直流／交流電力変換装置を介して交流負荷に交流を給電し、かつ上記直流／直流電力変換装置を介して直流負荷に直流を給電する回路のいずれかを用い、上記分散電源装置として直流発電装置の出力側に直列接続の充放電制御装置と蓄電装置とを並列に接続した回路を用い、上記双方向逆変換電力装置に上記商用交流電力系統から上記直流配電線に補充される補充電力を検出する補充電力検出装置を設け、上記変換制御装置に上記補充電力が所定値を越えたか否かを判断しかつ上記補充電力が所定値を越えたと判断したとき上記充放電制御装置に起動信号を出力する判断装置を設ける。
【００１５】
図１は参考例の分散給電ネットワークを示す図である。図に示すように、商用交流電力系統１１に系統保護装置１２が接続され、系統保護装置１２に直流／交流電力変換を行なう第１の逆変換電力装置１３の交流側および交流／直流電力変換を行なう第２の逆変換電力装置１４の交流側が接続され、逆変換電力装置１３と逆変換電力装置１４とが並列（逆並列）に接続されており、逆変換電力装置１３と逆変換電力装置１４とにより並列接続回路（逆並列装置）が構成されている。すなわち、系統保護装置１２に直列に逆変換電力装置１３と逆変換電力装置１４とから構成された並列接続回路の交流側が接続されている。また、逆変換電力装置１３と逆変換電力装置１４とが並列に接続された並列接続回路の直流側に１以上の直流配電線１５から構成される直流配電線ネットワークが接続され、直流配電線１５に直流発電装置を有する複数の分散電源装置１６および複数の負荷１７が接続され、分散電源装置１６と負荷１７とが並列に接続され、一対の分散電源装置１６、負荷１７が個人住宅、集合住宅、学校、オフィスなどに設置されている。そして、直流配電線１５、分散電源装置１６、負荷１７により直流配電線システムが構成されている。また、逆変換電力装置１３と逆変換電力装置１４とを制御する変換制御装置（共通制御部）１８が設けられ、分散電源装置１６と変換制御装置１８とは電気ケーブル、光ケーブル、無線などの双方向に信号が伝送できる信号伝送手段によって接続されている。そして、分散電源装置１６は識別番号、最適出力電力、動作・停止状態、出力電圧、出力電力、温度などの状態情報を常に記憶する記憶装置を有し、状態情報を状態通知信号として変換制御装置１８に送出する送出装置を有している。また、変換制御装置１８は一定時間ごとに各分散電源装置１６をスキャンし、各分散電源装置１６から送出された状態通知信号を記憶する記憶装置（データベース）を有するとともに、各分散電源装置１６の出力電力を積算する電力積算装置を有する。
【００１６】
この分散給電ネットワークにおいては、たとえば特定の分散電源装置１６の点検を行なう場合や特定の分散電源装置１６が故障した場合のように、特定の分散電源装置１６を停止する場合には、停止する分散電源装置１６はその識別番号、出力電力を変換制御装置１８に通知する。この場合、各分散電源装置１６の最適出力電力以内で特定の分散電源装置１６を動作する必要があるから、変換制御装置１８は停止する分散電源装置１６以外の各分散電源装置１６の出力電力情報を収集して積算し、変換制御装置１８が停止した分散電源装置１６の出力状態を検知し、逆変換電力装置１４を動作させて商用交流電力系統１１から直流配電線システムに電力を補充する。そして、停止していた分散電源装置１６が回復した場合には、変換制御装置１８は逆変換電力装置１４に動作停止信号を送出し、商用交流電力系統１１から直流配電線システムへの電力の補充を停止する。また、変換制御装置１８は逆変換電力装置１３と逆変換電力装置１４とを制御して、逆潮流ありの状態で動作する。したがって、逆変換電力装置１３は従来と同様に商用交流電力系統１１側と同期を取り、商用交流電力系統１１側とフィルタを通す前の位相差を調整し、交流電力の大きさと流れる方向を調整する。また、系統保護装置１２により商用交流電力系統１１側の安全性を確保することができる。また、直流配電線１５に接続された分散電源装置１６どうしは直流配電線ネットワークを介して電力の授受を行ない、できるだけ商用交流電力系統１１から電力を購入することのないように自律的に動作する。
【００１７】
このような分散給電ネットワークにおいては、商用交流電力系統に悪影響を与えることがなく、しかも直流配電線１５に分散電源装置１６を接続するから、各分散電源装置１６に対応して直流／交流電力変換装置を設ける必要がないので、構成が簡単になり、多数の分散電源装置１６が設けられている場合にも、多数の直流／交流電力変換装置を設ける必要がないため、設置コストが安価になる。また、直流給電線１５に分散電源装置１６を接続するから、分散電源装置１６を力率、位相を考慮した構成とする必要がないので、分散電源装置１６の構成が簡単になる。また、長距離の直流給電線１５を引き回したとしても、直流給電線１５から電磁波が発生することがないから、電磁波の影響によって妨害交流電圧や電源周波数の整数倍の高調波が発生することがない。
【００１８】
図２は本発明に係る分散給電ネットワークを示す図である。図に示すように、直流配電線１５と一対の分散電源装置１６、負荷１７との間に余剰不足電力検出装置２１が接続され、余剰不足電力検出装置２１は分散電源装置１６の発生電力から負荷１７の消費電力を減算した余剰不足電力を検出する。また、変換制御装置１８に演算装置２２、動作信号送出装置２３が設けられ、演算装置２２は各余剰不足電力検出装置２１により検出された余剰不足電力を積算した積算余剰不足電力を演算し、動作信号送出装置２３は積算余剰不足電力に応じた動作信号を逆変換電力装置１３、１４に送出する。すなわち、演算装置２２は直流配電線ネットワーク内で電力が余っているのか不足しているのかを判定し、演算装置２２が直流配電線ネットワーク内で電力が余っていると判定したときには、動作信号送出装置２３は逆変換電力装置１３を動作させて、直流配電線ネットワークから商用交流電力系統１１に電力を送出し、演算装置２２が直流配電線ネットワーク内で電力が不足していると判定したときには、動作信号送出装置２３は逆変換電力装置１４を動作させて、商用交流電力系統１１から直流配電線システムに電力を補充する。なお、余剰不足電力検出装置２１の出力はアナログである必要はなく、デジタル変換して送出し、演算装置２２においてもデジタル演算処理をすることができる。
【００１９】
この分散給電ネットワークにおいては、直流配電線ネットワーク内で電力が余っているときには、直流配電線ネットワークから商用交流電力系統１１に電力が送出され、直流配電線ネットワーク内で電力が不足しているときには、商用交流電力系統１１から直流配電線システムに電力が補充されるから、電力潮流の制御を正確に行なうことができる。また、余剰不足電力検出装置２１の検出値をもとにして直流配電線ネットワークの余剰電力、不足電力を検出するから、各分散電源装置１６や負荷１７の容量を正確に把握していなくても、電力潮流の制御を行なうことができる。また、余剰不足電力検出装置２１は直流の分散電源装置１６の電圧と余剰不足電力検出装置２１に流れる電流から余剰不足電力を求めることができるから、余剰不足電力を精度よく計測することができる。また、各分散電源装置１６を家庭やビルに設置された別々の需要家と見なした場合に、商用交流電力系統１１から購入した電力料金をどのように分配するかが問題になる場合があるが、変換制御装置１８に各分散電源装置１６に対応した余剰不足電力（消費電力）を記憶する記憶装置（データベース）を設け、各分散電源装置１６に対応した余剰不足電力に応じて電力料金を分配すれば、ある程度公平な集金が可能になる。
【００２０】
図３は本発明に係る他の分散給電ネットワークを示す図である。図に示すように、変換制御装置１８に発電制御装置（発電制御部）３１が設けられ、発電制御装置３１は演算装置２２、各分散電源装置１６に接続され、発電制御装置３１は演算装置２２の判定結果に基づいて各分散電源装置１６の出力電力を制御する。すなわち、演算装置２２は各余剰不足電力検出装置２１によって検出された余剰不足電力から余剰電力の合計値すなわち合計余剰電力を演算し、演算装置２２が合計余剰電力が第１の特定値以下であると判断したときには、発電制御装置３１は分散電源装置１６の出力電力を増加し、演算装置２２が合計余剰電力が第２の特定値以上であると判断したときには、発電制御装置３１は分散電源装置１６の出力電力を減少する。なお、各分散電源装置１６の出力電力を増減させる方法として、例えば分散電源装置１６が固体高分子型の燃料電池の場合には、流入ガスの量を増加、減少する装置を分散電源装置１６に設ける方法が考えられる。また、固体高分子型の燃料電池の場合には、作動温度が８０℃程度と低いので、燃料の増減に対して出力電力はかなり高速に応答可能である。
【００２１】
つぎに、図４により図３に示した分散給電ネットワークおける動作を説明する。まず、余剰不足電力検出装置２１が余剰不足電力を検出し、演算装置２２が合計余剰電力を演算し、演算装置２２が合計余剰電力が第１の特定値以下であると判断したときには、発電制御装置３１が分散電源装置１６の出力電力を増加し、演算装置２２が合計余剰電力が第２の特定値以上であると判断したときには、発電制御装置３１が分散電源装置１６の出力電力を減少する。なお、演算装置２２の合計余剰電力の演算はタイムインターバルをおいて行なうことが適切であり、分散電源装置１６の出力電力を最大に増加しても直流配電線システムの全消費電力に足りない場合には、逆変換電力装置１４を作動させて、商用交流電力系統１１からの援助を求める。
【００２２】
この分散給電ネットワークにおいては、演算装置２２内に各分散電源装置１６の識別番号と直流発電装置の単位出力当たりの価格すなわち発電単価とを記憶する記憶装置を設け、演算装置２２から発電単価の安い直流発電装置を有する分散電源装置１６から出力電力の増加を図るように発電制御装置３１に通知し、演算装置２２から発電単位の高い直流発電装置を有する分散電源装置１６から出力電力の減少を図るように発電制御装置３１に通知するよう構成すれば、直流配電線ネットワーク内の電力利用料金を減少することができる。
【００２３】
図５は本発明に係る分散給電ネットワークの分散電源装置の構成例を示す図である。図に示すように、直流発電装置４１に直流／直流電力変換装置４２が直列に接続され、直流発電装置４１、直流／直流電力変換装置４２により分散電源装置１６ａが構成されている。すなわち、直流発電装置４１と直流／直流電力変換装置４２との直列回路により分散電源装置１６ａが構成されている。
【００２４】
この分散電源装置においては、直流発電装置４１の出力電圧が出力電流により変動したとしても、直流／直流電力変換装置４２により直流配電線１５の電圧を安定化することができる。なお、直流発電装置４１としては、現在、燃料電池や太陽電池が主力であり、数百Ｗから１００ｋＷを超える選択範囲の広い装置が使用可能である。
【００２５】
図６は本発明に係る分散給電ネットワークの他の分散電源装置の構成例を示す図である。図に示すように、直流発電装置４１に直流／直流電力変換装置４２が直列に接続され、直流発電装置４１と並列に直列接続の充放電制御装置４３と蓄電装置４４とから構成されるエネルギー蓄積装置が接続され、直流発電装置４１、直流／直流電力変換装置４２、充放電制御装置４３、蓄電装置４４により分散電源装置１６ｂが構成されている。すなわち、充放電制御装置４３および蓄電装置４４を直列に接続したエネルギー蓄積装置と直流発電装置４１とを並列に接続した回路に直流／直流電力変換装置４２を接続した回路により分散電源装置１６ｂが構成されている。そして、蓄電装置４４は鉛蓄電池、Ｎｉ−ＭＨ電池、リチウム電池等の化学的な反応を利用したセル、あるいは電気二重層キャパシタなどの電気部品を用いて構成される。また、エネルギー蓄積装置の充放電制御装置４３は蓄電装置４４を充電し、必要に応じて放電させる。
【００２６】
この分散電源装置においては、エネルギー蓄積装置が直流発電装置４１の出力電力の一部を蓄積しておき、非常時には放出するから、蓄電装置４４を有する分散電源装置１６ｂは無停電電源であり、また蓄電装置４４により電力平準化を行なうことができ、また急激な負荷変動に対応することができるので、分散電源装置１６ｂの信頼度は高い。
【００２７】
なお、特に蓄電装置４４が化学的な反応を利用したセルの場合には、満充電や最大放電量の検出が難しく、製造メーカにより多くのノウハウ（例えば満充電を電池電圧のピーク値や温度上昇率で検出する方法や、最大放電量をガスゲージにより測定するがこの値を自己放電量、温度および経年変化で修正する方法）がある。
【００２８】
図７は本発明に係る分散給電ネットワークの負荷の構成例を示す図である。図に示すように、直流配電線１５に直流を交流に変換する直流／交流電力変換装置（インバータ）５１が接続され、直流／交流電力変換装置５１に交流負荷５２が直列に接続され、直流／交流電力変換装置５１、交流負荷５２により負荷１７ａが構成されている。すなわち、直流／交流電力変換装置５１を介して交流負荷５２に交流を給電する回路により負荷１７ａが構成されている。
【００２９】
このような負荷１７ａを有する分散給電ネットワークにおいては、直流／交流電力変換装置５１は商用交流電力系統１１と連系する必要がないから、構成は非常に簡単である。
【００３０】
図８は本発明に係る分散給電ネットワークの他の負荷の構成例を示す図である。図に示すように、直流配電線１５に直流を直流に変換する直流／直流電力変換装置（コンバータ）５３が接続され、直流／直流電力変換装置５３に直流負荷５４が直列に接続され、直流／直流電力変換装置５３、直流負荷５４により負荷１７ｂが構成されている。すなわち、直流／直流電力変換装置５３を介して直流負荷５４に直流を給電する回路により負荷１７ｂが構成されている。
【００３１】
このような負荷１７ｂを有する分散給電ネットワークにおいては、直流負荷５４の必要な電圧が直流配電線１５の電圧と異なる場合にも、直流負荷５４を作動させることができる。
【００３２】
なお、直流負荷５４の必要な電圧が直流配電線１５の電圧とが同じであれば直流／直流電力変換装置５３は省略することができる。
【００３３】
図９は本発明に係る分散給電ネットワークの他の負荷の構成例を示す図である。図に示すように、直流配電線１５に直流／交流電力変換装置５１および直流／直流電力変換装置５３が接続され、直流／交流電力変換装置５１と直流／直流電力変換装置５３とが並列に接続され、直流／交流電力変換装置５１に交流負荷５２が直列に接続され、直流／直流電力変換装置５３に直流負荷５４が直列に接続され、直流／交流電力変換装置５１、交流負荷５２、直流／直流電力変換装置５３、直流負荷５４により負荷１７ｃが構成されている。すなわち、直流／交流電力変換装置５１と直流／直流電力変換装置５３とを直流配電線１５側で並列に接続し、直流／交流電力変換装置５１を介して交流負荷５２に交流を給電し、かつ直流／直流電力変換装置５３を介して直流負荷５４に直流を給電する回路により負荷１７ｃが構成されている。
【００３４】
このような負荷１７ｃを有する分散給電ネットワークにおいては、交流負荷５２および直流負荷５４の両方に電力を供給することができるから、現在の交流中心の給電系にも充分対応可能であり、同時に直流負荷５４にも給電することができる。
【００３５】
図１０は本発明に係る他の分散給電ネットワークを示す図である。図に示すように、逆変換電力装置１４に逆変換電力装置１４の通過電力すなわち商用交流電力系統１１から直流配電線１５に補充される補充電力を検出する補充電力検出装置６１が設けられ、変換制御装置１８に補充電力検出装置６１により検出された補充電力が所定値を越えたか否かを判断しかつ補充電力が所定値を越えたと判断したとき充放電制御装置４３に起動信号を出力する判断装置６２が設けられている。
【００３６】
この分散給電ネットワークにおいては、補充電力検出装置６１により検出された補充電力が所定値を越えたときには、判断装置６２が蓄電装置４４に接続された充放電制御装置４３に起動信号を出力し、起動信号により蓄電装置４４は直ちに直流配電線１５に分散電源装置１６ｂの直流発電装置４１と協力して直流電力を送出する。このため、直流配電線ネットワークの直流電力消費量が一時的に上昇したときにも、補充電力が所定値を超えるのを防止することができるから、商用交流電力系統１１を有する電力会社との補充電力の契約量を超えるのを防止することができ、また逆変換電力装置１４の定格出力を超えるのを防止することができるので、逆変換電力装置１４を保護することができる。
【００３７】
図１１は参考例の分散給電ネットワークを示す図である。図に示すように、直流配電線１５に負荷１７と並列に複数のコンデンサ７１が接続されている。
【００３８】
この分散給電ネットワークにおいては、直流配電線システムの給電系はＬＲＣの回路を構成するから、条件によっては発振するおそれがあるが、直流配電線１５にコンデンサ７１を接続しているので、直流配電線システムの給電系が発振するのを防止することができる。
【００３９】
なお、上述実施の形態においては、双方向逆変換電力装置として逆変換電力装置１３と逆変換電力装置１４とが並列に接続された並列接続回路を用いたが、双方向逆変換電力装置として直流／交流電力変換機能および交流／直流電力変換機能を有する逆変換電力装置を用いてもよく、この場合には双方向逆変換電力装置をコンパクト化することができる。
【００４０】
【発明の効果】
本発明に係る分散給電ネットワークにおいては、商用交流電力系統に悪影響を与えることがなく、かつ直流配電線に分散電源装置を接続するから、各分散電源装置に対応して直流／交流電力変換装置を設ける必要がなく、しかも分散電源装置を力率、位相を考慮した構成とする必要がないので、構成が簡単になる。
【００４１】
また、分散電源装置の発生電力から負荷の消費電力を減算した余剰不足電力を検出する余剰不足電力検出装置を設け、変換制御装置に余剰不足電力検出装置により検出された余剰不足電力を積算した積算余剰不足電力を演算する演算装置を設け、変換制御装置に積算余剰不足電力に応じた動作信号を双方向逆変換電力装置に送出する動作信号送出装置を設けたときには、電力潮流の制御を正確に行なうことができる。
【００４２】
また、演算装置により各余剰不足電力から余剰電力の合計値すなわち合計余剰電力を演算し、合計余剰電力に基づいて各分散電源装置の出力電力を制御する発電制御装置を変換制御装置に設けたときには、直流配電線ネットワーク内の電力利用料金を減少することができる。
【００４３】
また、分散電源装置として、直流発電装置と直流／直流電力変換装置との直列回路を用いたときには、直流発電装置の出力電圧が出力電流により変動したとしても、直流配電線の電圧を安定化することができる。
【００４４】
また、分散電源装置として、充放電制御装置および蓄電装置を直列に接続したエネルギー蓄積装置と直流発電装置とを並列に接続した回路に直流／直流電力変換装置を接続した回路を用いたときには、蓄電装置により電力平準化を行なうことができ、また急激な負荷変動に対応することができるので、分散電源装置の信頼度を高くすることができる。
【００４５】
また、負荷として、直流／交流電力変換装置を介して交流負荷に交流を給電する回路を用いたときには、直流／交流電力変換装置は商用交流電力系統と連系する必要がないから、構成は非常に簡単である。
【００４６】
また、負荷として、直流／直流電力変換装置を介して直流負荷に直流を給電する回路を用いたときには、直流負荷の必要な電圧が直流配電線の電圧と異なる場合にも、直流負荷を作動させることができる。
【００４７】
また、負荷として、直流／交流電力変換装置と直流／直流電力変換装置とを直流配電線側で並列に接続し、直流／交流電力変換装置を介して交流負荷に交流を給電し、かつ直流／直流電力変換装置を介して直流負荷に直流を給電する回路を用いたときには、交流負荷および直流負荷の両方に電力を供給することができるから、交流中心の給電系にも充分対応可能であり、同時に直流負荷にも給電することができる。
【００４８】
また、分散電源装置として直流発電装置の出力側に直列接続の充放電制御装置と蓄電装置とを並列に接続した回路を用い、双方向逆変換電力装置に商用交流電力系統から直流配電線に補充される補充電力を検出する補充電力検出装置を設け、変換制御装置に補充電力が所定値を越えたか否かを判断しかつ補充電力が所定値を越えたと判断したとき充放電制御装置に起動信号を出力する判断装置を設けたときには、直流配電線ネットワークの直流電力消費量が一時的に上昇したときにも、補充電力が所定値を超えるのを防止することができ、また逆変換電力装置の定格出力を超えるのを防止することができる。
【図面の簡単な説明】
【図１】参考例の分散給電ネットワークを示す図である。
【図２】本発明に係る分散給電ネットワークを示す図である。
【図３】本発明に係る他の分散給電ネットワークを示す図である。
【図４】図３に示した分散給電ネットワークおける動作の説明図である。
【図５】本発明に係る分散給電ネットワークの分散電源装置の構成例を示す図である。
【図６】本発明に係る分散給電ネットワークの他の分散電源装置の構成例を示す図である。
【図７】本発明に係る分散給電ネットワークの負荷の構成例を示す図である。
【図８】本発明に係る分散給電ネットワークの他の負荷の構成例を示す図である。
【図９】本発明に係る分散給電ネットワークの他の負荷の構成例を示す図である。
【図１０】本発明に係る他の分散給電ネットワークを示す図である。
【図１１】参考例の分散給電ネットワークを示す図である。
【図１２】従来の分散給電ネットワークを示す図である。
【符号の説明】
１１…商用交流電力系統
１２…系統保護装置
１３…第１の逆変換電力装置
１４…第２の逆変換電力装置
１５…直流配電線
１６…分散電源装置
１７…負荷
１８…変換制御装置
２１…余剰不足電力検出装置
２２…演算装置
２３…動作信号送出装置
３１…発電制御装置
４１…直流発電装置
４２…直流／直流電力変換装置
４３…充放電制御装置
４４…蓄電装置
５１…直流／交流電力変換装置
５２…交流負荷
５３…直流／直流電力変換装置
５４…直流負荷
６１…補充電力検出装置
６２…判断装置
７１…コンデンサ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a distributed power supply network linked to a commercial AC power system through a system protection device.
[0002]
[Prior art]
At present, active use of energy (cogeneration, use of natural energy, etc.) is actively carried out by linking commercial AC power systems with distributed power supply devices having DC power generation devices such as solar cells and fuel cells. In this case, since the distributed power supply device is installed in the demand area, long-distance power transmission is unnecessary. The results of study on such a distributed power supply network are summarized in, for example, “Explanation: Power System Technical Requirements Guidelines '98 (Edited by the Agency for Natural Resources and Energy)”. DC power generators are connected to AC systems via DC / AC power converters. It is described to be connected.
[0003]
FIG. 12 is a diagram showing a conventional distributed power supply network. As shown in the figure, a plurality of AC distribution lines 3 are connected to a commercial AC power system 1 via a system protection device 2, and a load 6 and a DC / AC power converter (DC / AC inverter) 5 are connected to the AC distribution line 3. The DC power generator 4 is connected via
[0004]
[Problems to be solved by the invention]
In this distributed power supply network, since the DC power generation device 4 cannot be directly connected to the AC distribution line 3, the DC power generation device 4 is connected to the AC distribution line 3 via the DC / AC power conversion device 5. Since it is necessary to provide the DC / AC power converter 5 corresponding to the device 4, the configuration becomes complicated, and when a large number of DC power generators 4 are provided, a large number of DC / AC power converters 5 are provided. Since it is necessary to provide, installation cost becomes expensive. When the DC / AC power converter 5 is connected to the AC distribution line 3, the phase of the AC output of the DC / AC power converter 5 and the phase of the AC distribution line 3 are matched to prevent an inrush current. It is also necessary to arrange the AC output. If the output voltage of the DC power generation device 4 is too low and does not satisfy the magnitude of the AC output, the DC power generation device 4 may require a DC / DC power conversion device that boosts the direct current. For example, in the “Explanation: Power System Technical Requirements Guidelines '98” shown above, as an example, when there is a reverse power flow in a DC / AC power converter, that is, the power traveling from the premises of the private power generation facility to the AC power system side In order to prevent a voltage increase, the power factor at the power receiving point is 85% or more in principle, and it is described that the power factor does not become the forward power factor when viewed from the AC power system. As described above, in order to connect the DC power generation device 4 to the distributed power supply network having the conventional AC power supply line 3, it is necessary to provide strict restrictions so as not to adversely affect conventional consumers of the commercial AC power system 1. is there. For this reason, when connecting the DC power generation device 4 to the AC power supply line 3, the DC power generation device 4 and the DC / AC power conversion device 5 need to be configured in consideration of the power factor, phase, and the like. Since the configuration of the device 4 and the DC / AC power converter 5 is complicated, the installation cost becomes expensive. In addition, since the long-distance AC distribution line 3 is routed, electromagnetic waves are generated from the AC distribution line 3, and there is a possibility that harmonics that are integral multiples of the disturbing AC voltage and the power supply frequency may be generated due to the influence.
[0005]
Thus, the method of converting the output power of the DC power generation device 4 by the DC / AC power conversion device 5 and connecting it to the AC distribution line 3 is effective when most of the power supply is performed by AC. It is. However, when we look around, the only thing that really needs AC power is a washing machine using a rotating machine, a refrigerator, an air conditioner, a ventilating fan, etc., and many electronic devices convert AC to DC and use it. ing. Nevertheless, when the network of the distribution line is configured with an AC system, it is necessary to perform a cooperative operation with each DC power generation device 4 so as not to adversely affect the commercial AC power system 1, A large number of protective devices are required, and a technique for reducing electromagnetic waves generated from the AC distribution line 3 is required. When the DC power generation device 4 performs reverse power flow, it is installed for each DC power generation device 4. It is necessary to install a reverse power flow device for each DC / AC power conversion device 5, and the configuration becomes complicated.
[0006]
SUMMARY An advantage of some aspects of the invention is to provide a distributed power supply network that does not adversely affect a commercial AC power system and has a simple configuration.
[0007]
[Means for Solving the Problems]
  In order to achieve this object, in the present invention, both DC / AC power conversion and AC / DC power conversion are performed on the system protection device in a distributed power supply network linked to a commercial AC power system via the system protection device. Connecting the alternating current side of the reverse conversion power device, connecting a DC distribution line to the DC side of the bidirectional reverse conversion power device, connecting a plurality of distributed power supply devices and a plurality of loads to the DC distribution line, and A conversion control device is provided to control the bidirectional reverse conversion power device.A surplus / underpower detection device that detects surplus / underpower detection by subtracting the power consumption of the load from the generated power of the distributed power supply device, and the conversion control device receives the surplus / underpower detection by the surplus / underpower detection device. An arithmetic device that calculates the integrated accumulated surplus / underpower is provided, and an operation signal sending device that sends an operation signal corresponding to the accumulated surplus / underpower to the bidirectional reverse conversion power device is provided in the conversion control device.The
[0008]
Here, as the bidirectional inverse conversion power device, a parallel connection circuit in which an inverse conversion power device that performs DC / AC power conversion and an inverse conversion power device that performs AC / DC power conversion are connected in parallel, DC / AC power An inverse conversion power device having a conversion function and an AC / DC power conversion function can be used.
[0010]
In this case, the arithmetic unit calculates the total value of surplus power, that is, the total surplus power from each surplus power shortage, and converts the power generation control device that controls the output power of each of the distributed power units based on the total surplus power to the conversion You may provide in a control apparatus.
[0011]
In addition, as the distributed power supply device, a series circuit of a DC power generation device and a DC / DC power conversion device, a charge / discharge control device, and a circuit in which an energy storage device connected in series with a power storage device and a DC power generation device are connected in parallel. Any of the circuits connected to the DC / DC power converter may be used.
[0012]
Further, as the load, a circuit for supplying alternating current to the alternating current load via the direct current / alternating current power converter, a circuit for supplying direct current to the direct current load via the direct current / direct current power converter, a direct current / alternating current power converter and direct current / DC power converter is connected in parallel on the DC distribution line side, AC is supplied to the AC load via the DC / AC power converter, and the DC load is supplied via the DC / DC power converter. Any of circuits that supply direct current may be used.
[0013]
  Also, in a distributed power supply network linked to a commercial AC power system via a system protection device, the AC side of a bidirectional reverse conversion power device that performs DC / AC power conversion and AC / DC power conversion is connected to the system protection device. A DC distribution line connected to the DC side of the bidirectional reverse conversion power device, a plurality of distributed power supply devices and a plurality of loads are connected to the DC distribution line, and the bidirectional reverse conversion power device is controlled. A control device is provided, and a circuit in which a charge / discharge control device connected in series and a power storage device are connected in parallel on the output side of the DC power generator is used as the distributed power supply device, and the commercial AC power system is connected to the bidirectional reverse conversion power device. Provided with a supplementary power detecting device for detecting supplementary power supplemented to the DC distribution line, determining whether or not the supplementary power exceeds a predetermined value in the conversion control device, and the supplementary power reaches a predetermined value. When it is determined that there was example provided a decision apparatus for outputting an activation signal to the charge-discharge control device.
Also, in a distributed power supply network linked to a commercial AC power system via a system protection device, the AC side of a bidirectional reverse conversion power device that performs DC / AC power conversion and AC / DC power conversion is connected to the system protection device. A DC distribution line connected to the DC side of the bidirectional reverse conversion power device, a plurality of distributed power supply devices and a plurality of loads are connected to the DC distribution line, and the bidirectional reverse conversion power device is controlled. A control device is provided, and a surplus / underpower detection device that detects surplus / shortage power obtained by subtracting the power consumption of the load from the generated power of the distributed power supply device is provided, and the conversion control device is detected by the surplus / underpower detection device. An arithmetic device that calculates the accumulated surplus / short power obtained by accumulating the surplus / underpower is provided, and an operation signal corresponding to the accumulated surplus / short power is sent to the bidirectional reverse conversion power device in the conversion control device. A circuit in which a charge / discharge control device connected in series and a power storage device are connected in parallel to the output side of the direct current power generator as the distributed power supply device, and the bidirectional reverse conversion power device is configured as described above. A supplementary power detection device for detecting supplementary power supplemented to the DC distribution line from a commercial AC power system is provided, the conversion control device determines whether or not the supplementary power exceeds a predetermined value, and the supplementary power is predetermined. A determination device that outputs a start signal to the charge / discharge control device when it is determined that the value has been exceeded may be provided.
Also, in a distributed power supply network linked to a commercial AC power system via a system protection device, the AC side of a bidirectional reverse conversion power device that performs DC / AC power conversion and AC / DC power conversion is connected to the system protection device. A DC distribution line connected to the DC side of the bidirectional reverse conversion power device, a plurality of distributed power supply devices and a plurality of loads are connected to the DC distribution line, and the bidirectional reverse conversion power device is controlled. A control device is provided, and a surplus / underpower detection device that detects surplus / shortage power obtained by subtracting the power consumption of the load from the generated power of the distributed power supply device is provided, and the conversion control device is detected by the surplus / underpower detection device. An arithmetic device that calculates the accumulated surplus / short power obtained by accumulating the surplus / underpower is provided, and an operation signal corresponding to the accumulated surplus / short power is sent to the bidirectional reverse conversion power device in the conversion control device. An operation signal sending device is provided, and the arithmetic device calculates a total value of surplus power, that is, total surplus power from each surplus power shortage, and controls output power of each of the distributed power supply devices based on the total surplus power. A power generation control device is provided in the conversion control device,As the distributed power supply device, a circuit in which a charge / discharge control device connected in series and a power storage device are connected in parallel to the output side of the DC power generator is used, and the DC power distribution line is connected to the bidirectional reverse conversion power device from the commercial AC power system. A replenishment power detecting device for detecting replenishment power to be replenished, and determining whether or not the replenishment power exceeds a predetermined value in the conversion control device, and determining that the replenishment power exceeds a predetermined value. You may provide the determination apparatus which outputs a starting signal to a discharge control apparatus.
Also, in a distributed power supply network linked to a commercial AC power system via a system protection device, the AC side of a bidirectional reverse conversion power device that performs DC / AC power conversion and AC / DC power conversion is connected to the system protection device. A DC distribution line connected to the DC side of the bidirectional reverse conversion power device, a plurality of distributed power supply devices and a plurality of loads are connected to the DC distribution line, and the bidirectional reverse conversion power device is controlled. A control device is provided, and as the load, a circuit that supplies AC to the AC load via a DC / AC power converter, a circuit that supplies DC to the DC load via a DC / DC power converter, DC / AC power conversion A device and a DC / DC power converter are connected in parallel on the DC distribution line side, AC is supplied to an AC load via the DC / AC power converter, and Using one of the circuits that feed direct current to a direct current load via a direct current / direct current power converter, connect the charge / discharge control device connected in series and the power storage device in parallel to the output side of the direct current generator as the distributed power supply device. The bidirectional reverse conversion power device is provided with a supplementary power detection device for detecting supplementary power supplemented to the DC distribution line from the commercial AC power system, and the supplementary power is set to a predetermined value in the conversion control device. And a determination device that outputs a start signal to the charge / discharge control device when it is determined whether or not the supplementary power exceeds a predetermined value.
[0015]
  Figure 1Reference exampleIt is a figure which shows a distributed electric power feeding network. As shown in the figure, the system protection device 12 is connected to the commercial AC power system 11, and the AC side of the first reverse conversion power device 13 that performs DC / AC power conversion to the system protection device 12 and the AC / DC power conversion. The AC side of the second reverse conversion power device 14 to be performed is connected, the reverse conversion power device 13 and the reverse conversion power device 14 are connected in parallel (in reverse parallel), and the reverse conversion power device 13 and the reverse conversion power device 14 are connected. Thus, a parallel connection circuit (an antiparallel device) is configured. That is, the AC side of the parallel connection circuit configured by the reverse conversion power device 13 and the reverse conversion power device 14 is connected in series to the system protection device 12. In addition, a DC distribution network composed of one or more DC distribution lines 15 is connected to the DC side of the parallel connection circuit in which the reverse conversion power device 13 and the reverse conversion power device 14 are connected in parallel. A plurality of distributed power supply devices 16 having a DC power generator and a plurality of loads 17 are connected to each other, the distributed power supply device 16 and the load 17 are connected in parallel, and the pair of distributed power supply devices 16 and the load 17 are private houses and apartment houses. , Installed in schools, offices, etc. The DC distribution line system is constituted by the DC distribution line 15, the distributed power supply device 16, and the load 17. Moreover, the conversion control apparatus (common control part) 18 which controls the reverse conversion power apparatus 13 and the reverse conversion power apparatus 14 is provided, and the distributed power supply device 16 and the conversion control apparatus 18 are both an electric cable, an optical cable, a radio | wireless, etc. Are connected by signal transmission means capable of transmitting signals in the direction. The distributed power supply device 16 has a storage device that always stores state information such as an identification number, optimum output power, operating / stopped state, output voltage, output power, and temperature, and the conversion control device uses the state information as a state notification signal. 18 has a delivery device for delivery. In addition, the conversion control device 18 has a storage device (database) that scans each distributed power supply device 16 at regular intervals and stores a state notification signal transmitted from each distributed power supply device 16. A power integrating device for integrating the output power;
[0016]
In this distributed power supply network, when a specific distributed power supply 16 is stopped, for example, when a specific distributed power supply 16 is inspected or a specific distributed power supply 16 fails, the distributed power supply to be stopped is stopped. The power supply device 16 notifies the conversion control device 18 of the identification number and output power. In this case, since it is necessary to operate a specific distributed power supply device 16 within the optimum output power of each distributed power supply device 16, the conversion control device 18 outputs the output power information of each distributed power supply device 16 other than the distributed power supply device 16 to be stopped. Are collected and integrated, the output state of the distributed power supply device 16 stopped by the conversion control device 18 is detected, and the reverse conversion power device 14 is operated to replenish power from the commercial AC power system 11 to the DC distribution line system. Then, when the distributed power supply device 16 that has been stopped recovers, the conversion control device 18 sends an operation stop signal to the reverse conversion power device 14 and replenishes power from the commercial AC power system 11 to the DC distribution line system. To stop. Moreover, the conversion control apparatus 18 controls the reverse conversion power apparatus 13 and the reverse conversion power apparatus 14, and operate | moves in the state with a reverse power flow. Accordingly, the reverse conversion power device 13 is synchronized with the commercial AC power system 11 side in the same manner as in the past, adjusts the phase difference before passing through the filter with the commercial AC power system 11 side, and adjusts the magnitude and flowing direction of the AC power. To do. Further, the system protection device 12 can ensure the safety of the commercial AC power system 11 side. Further, the distributed power supply devices 16 connected to the DC distribution line 15 exchange power via the DC distribution line network and operate autonomously so as not to purchase power from the commercial AC power system 11 as much as possible. .
[0017]
In such a distributed power supply network, the commercial AC power system is not adversely affected, and since the distributed power supply device 16 is connected to the DC distribution line 15, DC / AC power conversion corresponding to each distributed power supply device 16 is performed. Since it is not necessary to provide a device, the configuration is simplified, and even when a large number of distributed power supply devices 16 are provided, it is not necessary to provide a large number of DC / AC power conversion devices, so the installation cost is low. . Further, since the distributed power supply device 16 is connected to the DC power supply line 15, it is not necessary to configure the distributed power supply device 16 in consideration of the power factor and phase, so that the configuration of the distributed power supply device 16 is simplified. Further, even when the long-distance DC power supply line 15 is routed, electromagnetic waves are not generated from the DC power supply line 15, and therefore, interference AC voltage and harmonics that are integral multiples of the power supply frequency may be generated due to the influence of the electromagnetic waves. Absent.
[0018]
  FIG. 2 shows the present invention.Such dispersionIt is a figure which shows an electric power feeding network. As shown in the figure, a surplus / underpower detection device 21 is connected between the DC distribution line 15, a pair of distributed power supply devices 16, and a load 17. The surplus power shortage obtained by subtracting the power consumption of 17 is detected. In addition, the conversion control device 18 is provided with an arithmetic device 22 and an operation signal sending device 23. The arithmetic device 22 calculates an integrated surplus / short power obtained by integrating the surplus / short power detected by the surplus / short power detection devices 21, and operates. The signal transmission device 23 transmits an operation signal corresponding to the accumulated surplus and shortage power to the inverse conversion power devices 13 and 14. That is, the arithmetic unit 22 determines whether there is a surplus or a shortage of power in the DC distribution line network, and when the calculation unit 22 determines that there is a surplus of power in the DC distribution line network, an operation signal is transmitted. When the device 23 operates the reverse conversion power device 13 to send power from the DC distribution line network to the commercial AC power system 11, and when the arithmetic unit 22 determines that the power is insufficient in the DC distribution line network, The operation signal sending device 23 operates the reverse conversion power device 14 to replenish power from the commercial AC power system 11 to the DC distribution line system. Note that the output of the surplus / underpower detection device 21 does not have to be analog, and can be digitally converted and sent out, and the arithmetic device 22 can also perform digital arithmetic processing.
[0019]
In this distributed power supply network, when there is surplus power in the DC distribution line network, power is sent from the DC distribution line network to the commercial AC power system 11, and when power is insufficient in the DC distribution line network, Since power is replenished from the commercial AC power system 11 to the DC distribution line system, the power flow can be controlled accurately. Moreover, since the surplus power and the shortage power of the DC distribution network are detected based on the detection value of the surplus and shortage power detection device 21, even if the capacity of each distributed power supply device 16 and the load 17 is not accurately grasped. The power flow can be controlled. Moreover, since the surplus / shortage power detection device 21 can obtain the surplus / shortage power from the voltage of the DC distributed power supply device 16 and the current flowing through the surplus / shortage power detection device 21, the surplus / shortage power can be accurately measured. Further, when each distributed power supply device 16 is regarded as a separate consumer installed in a home or building, there is a case in which how to distribute the power charge purchased from the commercial AC power system 11 may be a problem. However, the conversion control device 18 is provided with a storage device (database) for storing surplus and deficient power (power consumption) corresponding to each distributed power supply device 16, and the power charge is set according to the surplus and deficient power corresponding to each distributed power supply device 16. If distributed, it will be possible to collect funds fairly evenly.
[0020]
FIG. 3 is a diagram showing another distributed power supply network according to the present invention. As shown in the figure, the conversion control device 18 is provided with a power generation control device (power generation control unit) 31. The power generation control device 31 is connected to the arithmetic device 22 and each of the distributed power supply devices 16, and the power generation control device 31 is connected to the arithmetic device 22. Based on the determination result, the output power of each distributed power supply device 16 is controlled. That is, the arithmetic device 22 calculates the total value of surplus power, that is, the total surplus power, from the surplus power shortage detected by each surplus / underpower detection device 21, and the arithmetic device 22 has the total surplus power equal to or less than the first specific value. When it is determined that the power generation control device 31 increases the output power of the distributed power supply device 16, the power generation control device 31 determines that the total surplus power is greater than or equal to the second specific value. 16 output power is reduced. As a method for increasing or decreasing the output power of each distributed power supply device 16, for example, when the distributed power supply device 16 is a solid polymer fuel cell, a device that increases or decreases the amount of inflow gas is used as the distributed power supply device 16. A method of providing it can be considered. In the case of a polymer electrolyte fuel cell, since the operating temperature is as low as about 80 ° C., the output power can respond to the increase / decrease of the fuel considerably fast.
[0021]
Next, the operation of the distributed power supply network shown in FIG. 3 will be described with reference to FIG. First, when the surplus / underpower detection device 21 detects surplus / underpower, the arithmetic device 22 calculates the total surplus power, and the arithmetic device 22 determines that the total surplus power is equal to or less than the first specific value, power generation control is performed. When the device 31 increases the output power of the distributed power supply device 16 and the arithmetic device 22 determines that the total surplus power is greater than or equal to the second specific value, the power generation control device 31 decreases the output power of the distributed power supply device 16. . In addition, it is appropriate that the calculation of the total surplus power of the calculation device 22 is performed at a time interval, and even when the output power of the distributed power supply device 16 is increased to the maximum, the total power consumption of the DC distribution line system is insufficient. In this case, the reverse conversion power device 14 is operated to seek assistance from the commercial AC power system 11.
[0022]
In this distributed power supply network, a storage device for storing the identification number of each distributed power supply device 16 and the price per unit output of the DC power generator, that is, the power generation unit price, is provided in the arithmetic unit 22. The power generation control device 31 is notified so as to increase the output power from the distributed power supply device 16 having the DC power generation device, and the output power is reduced from the distributed power supply device 16 having the DC power generation device having a high power generation unit from the arithmetic device 22. Thus, if it comprises so that it may notify to the electric power generation control apparatus 31, the electric power usage fee in a DC distribution line network can be reduced.
[0023]
FIG. 5 is a diagram showing a configuration example of a distributed power supply apparatus of a distributed power supply network according to the present invention. As shown in the figure, a DC / DC power conversion device 42 is connected in series to a DC power generation device 41, and the DC power generation device 41 and the DC / DC power conversion device 42 constitute a distributed power supply device 16a. That is, the distributed power supply device 16 a is configured by a series circuit of the DC power generation device 41 and the DC / DC power conversion device 42.
[0024]
In this distributed power supply device, even if the output voltage of the DC power generation device 41 varies due to the output current, the DC / DC power conversion device 42 can stabilize the voltage of the DC distribution line 15. Note that as the DC power generation device 41, currently, fuel cells and solar cells are the mainstay, and devices with a wide selection range exceeding several hundred W to 100 kW can be used.
[0025]
FIG. 6 is a diagram showing a configuration example of another distributed power supply apparatus according to the present invention. As shown in the figure, a DC / DC power conversion device 42 is connected in series to a DC power generation device 41, and an energy storage composed of a charge / discharge control device 43 and a power storage device 44 connected in series with the DC power generation device 41 in parallel. The devices are connected, and the DC power generation device 41, the DC / DC power conversion device 42, the charge / discharge control device 43, and the power storage device 44 constitute a distributed power supply device 16b. That is, the distributed power supply device 16b is configured by a circuit in which the DC / DC power conversion device 42 is connected to a circuit in which the DC power generation device 41 and the energy storage device in which the charge / discharge control device 43 and the power storage device 44 are connected in series. Has been. And the electrical storage apparatus 44 is comprised using electric parts, such as a cell using chemical reactions, such as a lead storage battery, a Ni-MH battery, a lithium battery, or an electrical double layer capacitor. In addition, the charge / discharge control device 43 of the energy storage device charges the power storage device 44 and discharges it as necessary.
[0026]
In this distributed power supply device, since the energy storage device stores a part of the output power of the DC power generation device 41 and releases it in an emergency, the distributed power supply device 16b having the power storage device 44 is an uninterruptible power supply. The power storage device 44 can perform power leveling and can cope with sudden load fluctuations, so the reliability of the distributed power supply device 16b is high.
[0027]
In particular, in the case where the power storage device 44 is a cell using a chemical reaction, it is difficult to detect a full charge or a maximum discharge amount. And a method of measuring the maximum discharge amount with a gas gauge, but correcting this value with the self-discharge amount, temperature, and aging).
[0028]
FIG. 7 is a diagram showing a configuration example of the load of the distributed power supply network according to the present invention. As shown in the figure, a DC / AC power converter (inverter) 51 for converting DC to AC is connected to the DC distribution line 15, and an AC load 52 is connected in series to the DC / AC power converter 51. The AC power conversion device 51 and the AC load 52 constitute a load 17a. That is, the load 17 a is configured by a circuit that supplies AC to the AC load 52 via the DC / AC power converter 51.
[0029]
In the distributed power supply network having such a load 17a, the DC / AC power converter 51 does not need to be connected to the commercial AC power system 11, and thus the configuration is very simple.
[0030]
FIG. 8 is a diagram showing a configuration example of another load of the distributed power supply network according to the present invention. As shown in the figure, a DC / DC power converter (converter) 53 for converting DC to DC is connected to the DC distribution line 15, and a DC load 54 is connected in series to the DC / DC power converter 53. The DC power converter 53 and the DC load 54 constitute a load 17b. That is, the load 17 b is configured by a circuit that supplies direct current to the direct current load 54 through the direct current / direct current power converter 53.
[0031]
In the distributed power supply network having such a load 17b, the DC load 54 can be operated even when the required voltage of the DC load 54 is different from the voltage of the DC distribution line 15.
[0032]
The DC / DC power converter 53 can be omitted if the required voltage of the DC load 54 is the same as the voltage of the DC distribution line 15.
[0033]
FIG. 9 is a diagram showing a configuration example of another load of the distributed power supply network according to the present invention. As shown in the figure, a DC / AC power converter 51 and a DC / DC power converter 53 are connected to the DC distribution line 15, and the DC / AC power converter 51 and the DC / DC power converter 53 are connected in parallel. An AC load 52 is connected in series to the DC / AC power converter 51, a DC load 54 is connected in series to the DC / DC power converter 53, and the DC / AC power converter 51, AC load 52, DC / DC The DC power converter 53 and the DC load 54 constitute a load 17c. That is, the DC / AC power converter 51 and the DC / DC power converter 53 are connected in parallel on the DC distribution line 15 side, the AC load 52 is supplied with AC via the DC / AC power converter 51, and A load 17 c is configured by a circuit that feeds direct current to the direct current load 54 via the direct current / direct current power converter 53.
[0034]
In the distributed power supply network having such a load 17c, since power can be supplied to both the AC load 52 and the DC load 54, the power supply system of the present AC center can be sufficiently accommodated, and at the same time, the DC load 54 can also be fed.
[0035]
FIG. 10 is a diagram showing another distributed power supply network according to the present invention. As shown in the figure, the reverse conversion power device 14 is provided with a supplementary power detection device 61 that detects the passing power of the reverse conversion power device 14, that is, supplementary power supplemented to the DC distribution line 15 from the commercial AC power system 11. The controller 18 determines whether or not the supplementary power detected by the supplementary power detection device 61 exceeds a predetermined value, and determines that the activation signal is output to the charge / discharge control device 43 when it is determined that the supplementary power exceeds the predetermined value. A device 62 is provided.
[0036]
In this distributed power supply network, when the supplementary power detected by the supplementary power detection device 61 exceeds a predetermined value, the determination device 62 outputs a startup signal to the charge / discharge control device 43 connected to the power storage device 44 and starts the startup. In response to the signal, the power storage device 44 immediately sends DC power to the DC distribution line 15 in cooperation with the DC power generation device 41 of the distributed power supply device 16b. For this reason, since it is possible to prevent the supplementary power from exceeding a predetermined value even when the DC power consumption of the DC distribution network temporarily increases, supplementation with the power company having the commercial AC power system 11 is possible. Since it is possible to prevent exceeding the contract amount of power and to prevent exceeding the rated output of the reverse conversion power device 14, the reverse conversion power device 14 can be protected.
[0037]
  FIG.Reference exampleIt is a figure which shows a distributed electric power feeding network. As shown in the figure, a plurality of capacitors 71 are connected to the DC distribution line 15 in parallel with the load 17.
[0038]
In this distributed power supply network, the power supply system of the DC distribution line system constitutes an LRC circuit, so there is a risk of oscillation depending on conditions, but since the capacitor 71 is connected to the DC distribution line 15, the DC distribution line It is possible to prevent the power supply system of the system from oscillating.
[0039]
In the above-described embodiment, the parallel connection circuit in which the reverse conversion power device 13 and the reverse conversion power device 14 are connected in parallel is used as the bidirectional reverse conversion power device. A reverse conversion power device having an AC / AC power conversion function and an AC / DC power conversion function may be used. In this case, the bidirectional reverse conversion power device can be made compact.
[0040]
【The invention's effect】
In the distributed power supply network according to the present invention, since there is no adverse effect on the commercial AC power system and the distributed power supply device is connected to the DC distribution line, a DC / AC power conversion device corresponding to each distributed power supply device is provided. There is no need to provide it, and since it is not necessary to configure the distributed power supply device in consideration of the power factor and phase, the configuration is simplified.
[0041]
Also, a surplus / short power detection device that detects surplus / short power by subtracting the power consumption of the load from the generated power of the distributed power supply device is provided, and the integration is obtained by integrating the surplus / short power detected by the surplus / short power detection device in the conversion control device When an arithmetic device that calculates surplus and shortage power is provided and an operation signal sending device that sends an operation signal corresponding to the accumulated surplus and shortage power to the bidirectional reverse conversion power device is provided in the conversion control device, the power flow control is accurately performed. Can be done.
[0042]
In addition, when the conversion control device is provided with a power generation control device that calculates the total value of surplus power, that is, the total surplus power from each surplus shortage power by the arithmetic device, and controls the output power of each distributed power supply device based on the total surplus power The power usage fee in the DC distribution network can be reduced.
[0043]
Further, when a series circuit of a DC power generator and a DC / DC power converter is used as the distributed power supply device, the voltage of the DC distribution line is stabilized even if the output voltage of the DC power generator fluctuates due to the output current. be able to.
[0044]
When a circuit in which a DC / DC power converter is connected to a circuit in which an energy storage device in which a charge / discharge control device and a power storage device are connected in series and a DC power generation device are connected in parallel is used as the distributed power supply device, Since the power leveling can be performed by the apparatus and it is possible to cope with a sudden load fluctuation, the reliability of the distributed power supply apparatus can be increased.
[0045]
In addition, when a circuit that feeds alternating current to an alternating current load via a direct current / ac power converter is used as a load, the direct current / alternate power converter does not need to be linked to a commercial alternating current power system, so the configuration is very Easy to be.
[0046]
In addition, when a circuit that feeds direct current to a DC load via a DC / DC power converter is used as the load, the DC load is operated even when the required voltage of the DC load is different from the voltage of the DC distribution line. be able to.
[0047]
Further, as a load, a DC / AC power converter and a DC / DC power converter are connected in parallel on the DC distribution line side, AC is supplied to the AC load via the DC / AC power converter, and DC / AC When using a circuit that feeds direct current to a direct current load via a direct current power converter, power can be supplied to both the alternating current load and the direct current load. At the same time, it can supply power to the DC load.
[0048]
In addition, as a distributed power supply device, a circuit in which a charge / discharge control device connected in series and a power storage device are connected in parallel on the output side of the DC power generator is used, and a bidirectional reverse conversion power device is supplemented from the commercial AC power system to the DC distribution line. Provided with a supplementary power detection device for detecting supplemental power to be generated, and determining whether or not the supplementary power has exceeded a predetermined value in the conversion control device and when determining that the supplementary power has exceeded the predetermined value, a start signal to the charge / discharge control device Is provided, the supplementary power can be prevented from exceeding a predetermined value even when the DC power consumption of the DC distribution network temporarily rises, and the reverse conversion power device It is possible to prevent the rated output from being exceeded.
[Brief description of the drawings]
[Figure 1]Reference exampleIt is a figure which shows a distributed electric power feeding network.
FIG. 2 shows the present invention.Such dispersionIt is a figure which shows an electric power feeding network.
FIG. 3 is a diagram showing another distributed power supply network according to the present invention.
4 is an explanatory diagram of an operation in the distributed power supply network illustrated in FIG. 3;
FIG. 5 is a diagram illustrating a configuration example of a distributed power supply device of a distributed power supply network according to the present invention.
FIG. 6 is a diagram illustrating a configuration example of another distributed power supply apparatus according to the present invention.
FIG. 7 is a diagram illustrating a configuration example of a load of the distributed power supply network according to the present invention.
FIG. 8 is a diagram showing a configuration example of another load of the distributed power supply network according to the present invention.
FIG. 9 is a diagram illustrating a configuration example of another load of the distributed power supply network according to the present invention.
FIG. 10 is a diagram showing another distributed power supply network according to the present invention.
FIG. 11Reference exampleIt is a figure which shows a distributed electric power feeding network.
FIG. 12 shows a conventional distributed power supply network.
[Explanation of symbols]
11 ... Commercial AC power system
12 ... System protection device
13: First inverse conversion power device
14 ... Second inverse conversion power device
15 ... DC distribution line
16: Distributed power supply
17 ... Load
18 ... Conversion control device
21 ... Surplus / low power detection device
22: Arithmetic unit
23. Operation signal sending device
31 ... Power generation control device
41 ... DC generator
42 ... DC / DC power converter
43. Charge / discharge control device
44 ... Power storage device
51. DC / AC power converter
52 ... AC load
53 ... DC / DC power converter
54 ... DC load
61 ... Replenishment power detection device
62 ... Judgment device
71: Capacitor

Claims

In a distributed power supply network linked to a commercial AC power system via a system protection device, the AC side of a bidirectional reverse conversion power device that performs DC / AC power conversion and AC / DC power conversion is connected to the system protection device, A conversion control device for controlling the bidirectional reverse conversion power device by connecting a DC distribution line to the DC side of the bidirectional reverse conversion power device, connecting a plurality of distributed power supply devices and a plurality of loads to the DC distribution line. And a surplus / shortage power detection device that detects surplus / shortage power by subtracting the power consumption of the load from the generated power of the distributed power supply device, and the surplus / shortage detected by the surplus / shortage power detection device in the conversion control device An arithmetic device for calculating the accumulated surplus / shortage power obtained by integrating the power is provided, and an operation signal corresponding to the accumulated surplus / shortage power is sent to the conversion control device to the bidirectional reverse conversion power device. Distributed feed network, characterized in that a operation signal transmission apparatus.

A power generation control device that calculates a total value of surplus power from each surplus shortage power, that is, total surplus power by the arithmetic device, and controls output power of each of the distributed power supply devices based on the total surplus power is provided to the conversion control device. The distributed power supply network according to claim 1, wherein the distributed power supply network is provided.

As the above distributed power supply device, a DC / DC power converter is connected to a series circuit of a DC power generator and a DC / DC power converter, a charge / discharge control device and an energy storage device connected in series with a power storage device and a DC power generator connected in parallel. 2. The distributed power supply network according to claim 1, wherein any one of circuits connected to a DC power converter is used.

As the load, a circuit that supplies AC to the AC load via the DC / AC power converter, a circuit that supplies DC to the DC load via the DC / DC power converter, a DC / AC power converter, and DC / DC A power converter is connected in parallel on the DC distribution line side, AC is supplied to the AC load via the DC / AC power converter, and DC is supplied to the DC load via the DC / DC power converter. 2. The distributed power supply network according to claim 1, wherein any one of power supply circuits is used.

In a distributed power supply network linked to a commercial AC power system via a system protection device, the AC side of a bidirectional reverse conversion power device that performs DC / AC power conversion and AC / DC power conversion is connected to the system protection device, A conversion control device for controlling the bidirectional reverse conversion power device by connecting a DC distribution line to the DC side of the bidirectional reverse conversion power device, connecting a plurality of distributed power supply devices and a plurality of loads to the DC distribution line. And using a circuit in which a charge / discharge control device connected in series and a power storage device are connected in parallel on the output side of the DC power generator as the distributed power supply device, the bidirectional reverse conversion power device from the commercial AC power system to A supplementary power detection device for detecting supplementary power supplemented to the DC distribution line is provided, the conversion control device determines whether or not the supplementary power exceeds a predetermined value, and the supplementary power exceeds the predetermined value. Distributed feed network, characterized in that a determination device which outputs an activation signal to the charge and discharge control device when it is determined.

As the distributed power supply device, a circuit in which a charge / discharge control device connected in series and a power storage device are connected in parallel to the output side of the DC power generator is used, and the DC power distribution line is connected to the bidirectional reverse conversion power device from the commercial AC power system. A replenishment power detecting device for detecting replenishment power to be replenished, and determining whether or not the replenishment power exceeds a predetermined value in the conversion control device, and determining that the replenishment power exceeds a predetermined value. The distributed power supply network according to claim 1, wherein a determination device that outputs a start signal is provided in the discharge control device.

In a distributed power supply network linked to a commercial AC power system via a system protection device, the AC side of a bidirectional reverse conversion power device that performs DC / AC power conversion and AC / DC power conversion is connected to the system protection device, A conversion control device for controlling the bidirectional reverse conversion power device by connecting a DC distribution line to the DC side of the bidirectional reverse conversion power device, connecting a plurality of distributed power supply devices and a plurality of loads to the DC distribution line. A circuit for supplying alternating current to the alternating current load via a direct current / direct current power converter, a circuit for supplying direct current to the direct current load via the direct current / direct current power converter, and a direct current / alternating current power converter, A DC / DC power converter is connected in parallel on the DC distribution line side, AC is supplied to an AC load via the DC / AC power converter, and DC is supplied via the DC / DC power converter. One of the circuits for supplying direct current to the load, and using the circuit in which the charge / discharge control device connected in series and the power storage device are connected in parallel on the output side of the DC power generator as the distributed power supply device, The power device is provided with a supplementary power detection device for detecting supplementary power supplemented to the DC distribution line from the commercial AC power system, and the conversion control device determines whether or not the supplementary power exceeds a predetermined value and A distributed power supply network, comprising: a determination device that outputs a start signal to the charge / discharge control device when it is determined that supplementary power exceeds a predetermined value.