JP2004088900A - Power supply system - Google Patents

Power supply system Download PDF

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JP2004088900A
JP2004088900A JP2002246149A JP2002246149A JP2004088900A JP 2004088900 A JP2004088900 A JP 2004088900A JP 2002246149 A JP2002246149 A JP 2002246149A JP 2002246149 A JP2002246149 A JP 2002246149A JP 2004088900 A JP2004088900 A JP 2004088900A
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power generation
facility
storage battery
private
power
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Toshio Yoshida
吉田　利夫
Seiji Harada
原田　誠司
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Meidensha Corp
Meidensha Electric Manufacturing Co Ltd
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Meidensha Corp
Meidensha Electric Manufacturing Co Ltd
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    • 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

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  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To construct a rational system in capacity, voltage and power supply efficiency in a power supply system for linking a private power generation system in which a storage battery facility is coupled to a plurality of types of private power generation facilities, to a commercial power supply. <P>SOLUTION: A bus of a private power generation system is set to a DC line, the storage battery facility and the private power generation facility are coupled to the bus, a main facility having a generation power capacity is coupled directly to the DC line, and the other facility obtains voltage matching via a step-up or step-down chopper. When the storage battery or a private power generator which is larger than a power capacity requested by the system is used, in the storage battery facility or the private power generation facility, the number of cells of the storage battery or the number of serial connecting private power generators is reduced to be matched to the power capacity requested by the system, and a voltage difference with the DC voltage of the private power generation system is matched by the step-up/step-down chopper. The chopper is an opening/closing means for disconnecting the storage battery facility or the private power generation facility from the private power generation bus. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、蓄電池設備と複数種の自家発電設備（太陽光発電設備、風力発電設備、エンジン発電機、マイクロガスタービン発電機、燃料電池など）とを結合した自家発電系統を商用電源に連系する電源システムに関する。
【０００２】
【従来の技術】
この種の電源システムは、例えば、負荷電力が比較的小さくなる夜間には割安な夜間電力および自家発電設備の発電電力を蓄電池設備に貯蔵しておき、負荷電力が大きくなる昼間には蓄電池設備の貯蔵電力および自家発電設備の発電電力を受電系統側に放出することで、電力系統の負荷平準化、電力料低減、無停電対策、電源効率の向上、自然エネルギーの有効利用などを可能にする。
【０００３】
図５は、従来の電源システムの構成例を示す。商用電源からの受電系統と連系可能にする自家発電系統は、発電電源として太陽光発電設備１と、風力発電設備２と夜間電力を貯蔵する蓄電池設備３を直流系の自家発電母線に接続し、この自家発電系統と商用電源との間は交直双方向電力変換設備４による電力変換によって連系し、負荷に給電する。
【０００４】
このようなシステム構成において、太陽光発電設備１や風力発電設備２は、時間・季節や天候により発電電力が大きく変化するが、この安定化・平準化を蓄電池設備３による電力貯蔵や燃料電池の発電量調節で賄うことができる。しかも、太陽光発電設備などは直流発電となり、これらを直流−交流電力変換することなく、蓄電池設備や燃料電池とを直流系で結合することができる。
【０００５】
例えば、特開平６−７８４７５号公報では、バッテリに太陽光発電装置を並設し、太陽光発電装置から昇圧チョッパを通してバッテリを充電するものが開示されている。
【０００６】
なお、風力発電設備、エンジン発電機、マイクロガスタービン発電機などは、交流発電となり、これらをシステムに組み込む場合にはその発電電力を交流−直流電力変換することにより他の直流系発電設備と結合が可能となる。
【０００７】
【発明が解決しようとする課題】
前記のように、太陽光発電設備、蓄電池設備、燃料電池は、電力変換することなく直流結合できるが、互いの発電電圧が異なり、チョッパなど、直流−直流電力変換器による電圧調整を必要とする。
【０００８】
また、蓄電池設備は、その容量規格が段階的（例えば、２２０、３３０、６６０、１０００Ａｈ／１０ｈｒ）であり、これら同規格のものの並列数で容量が決まるが、段階的なものになる。また、蓄電池設備は、その直流電圧が直列接続セル数で決まるが、常に満杯状態で一定電圧の充電をしておく蓄電池とは異なり、高頻度充放電タイプであり、その充電量、蓄電量により直流電圧が大きく変化する。
【０００９】
以上のことから、発電方式の異なる複数の自家発電設備を結合しようとすると、容量および電圧の差異から互いを直接に結合するのを難しくしている。
【００１０】
一方、風力発電設備や太陽光発電設備は、風速、日照などで発電電力が大きく変化するため、広いレンジの電圧調整を必要とする。しかも、これら設備は、その特性から発電電圧をある値に設定したときに最大電力を取り出すことができ、直流電圧を変化させて最大電力を取り出すことができるが、他の発電設備との電圧調整をしようとすると、発電効率を低下させてしまう。
【００１１】
結果的に、自家発電設備の各種電源は、互いの結合に、容量、電圧、電源効率の上で効果的な電源システムの構築を難しくしていた。
【００１２】
本発明の目的は、上記の課題を解決した電源システムを提供することにある。
【００１３】
【課題を解決するための手段】
本発明は、上記の課題を解決するため、自家発電設備母線を直流系としその直流電圧をシステム容量的に最適な値に設定し、各発電設備毎にシステム電圧に整合させる昇降圧チョッパを組み込み結合することで、合理的な電源システムを構築できるようにしたもので、以下の構成を特徴とする。
【００１４】
（１）蓄電池設備と複数種の自家発電設備とを結合した自家発電系統を商用電源と連系させる電源システムにおいて、
前記自家発電系統の母線を直流系として前記蓄電池設備および自家発電設備を結合し、
前記蓄電池設備及び自家発電設備のうち、発電電力容量で主となる設備を前記直流系に直接に結合して自家発電系統の直流電圧とし、
他の蓄電池設備または自家発電設備はそれぞれ昇圧または降圧チョッパを介して自家発電系統の直流電圧との整合を得る構成としたことを特徴とする。
【００１５】
（２）蓄電池設備と複数種の自家発電設備とを結合した自家発電系統を商用電源と連系させる電源システムにおいて、
前記自家発電系統の母線を直流系として前記蓄電池設備および自家発電設備を結合し、
前記蓄電池設備または自家発電設備は、システムが要求する電力容量よりも大きい蓄電池または自家発電機を使用する場合、蓄電池のセル数または自家発電機の直列接続台数を減らしてシステムが要求する電力容量に合わせ、自家発電系統の直流電圧との電圧差は昇圧／降圧チョッパで整合させることを特徴とする。
【００１６】
（３）直流負荷をもつ電源システムにおいて、前記自家発電系統の直流母線から前記直流負荷に直接に電力供給できる電力変換器を設けたことを特徴とする。
【００１７】
（４）前記チョッパは、前記蓄電池設備または自家発電設備と自家発電母線との切り離しのための開閉手段としたことを特徴とする。
【００１８】
【発明の実施の形態】
（実施形態１）
図１は、本発明の実施形態を示すシステム構成図であり、自家発電系統は、発電電源として太陽光発電設備１と、風力発電設備２と蓄電池設備３を設け、交直双方向電力変換設備４によって自家発電系統と商用電源とを連系する場合である。
【００１９】
本実施形態では、太陽光発電設備が電力容量的に主たる電源となる場合に適用したもので、受電系統が３相２００Ｖ系になるのに対して、自家発電系統の母線電圧は直流４００Ｖとする。これに合わせて、他の自家発電設備（図示では風力発電設備２と蓄電池設備３）は、直流母線電圧と整合させた電力変換器を組み合わせた構成とする。この電力変換器は、風力発電設備２では整流器と昇降圧チョッパで構成した電力変換器２Ａとし、蓄電池設備３では昇降圧チョッパで構成した電力変換器３Ａとする。
【００２０】
コントローラ５は、運転指令部５Ａから電力変換制御部５Ｂ，５Ｃ，５Ｄに運転指令を発生し、各制御部５Ｂ，５Ｃによって電力変換器２Ａ、３Ａの電力変換制御を行い、制御部５Ｄによって電力変換設備４の電力融通制御を行う。これら制御には制御対象の出力電流、電圧等の検出信号を基に演算する。なお、制御部５Ｅは、太陽光発電設備１に風力発電設備２との整合のために電力変換器１Ａを介挿させて最大電力追従制御を行う場合のものである。
【００２１】
このように、主たる電源になる太陽光発電設備１には昇降圧チョッパを用いずにダイレクトに直流４００Ｖラインに接続し、他の発電設備になる風力発電設備２では整流器を含む昇降圧チョッパ２Ａを通して直流４００Ｖラインに接続し、蓄電池設備３は昇降圧チョッパ３Ａを通して直流４００Ｖラインに接続する。
【００２２】
このようなシステム構成とすることで、本実施形態では、容量、電圧、電源効率の上で効果的な電源システムを得ることができる。この理由を以下に詳細に説明する。
【００２３】
太陽光発電設備の場合、日照により最大電力を取り出せる直流電圧が大きく変化する。したがって、発電電圧は常に４００Ｖではなく、日射量によっては直流電圧が３００Ｖ前半にある場合に最大電力を取り出せる場合もある。また、直流電圧の変動という意味では、蓄電池設備３の放電により自家発電母線になる直流４００Ｖラインが大きく低下する。
【００２４】
したがって、直流４００Ｖラインは、実際には３００Ｖ前半から４００Ｖまでの間で変動することになる。この電圧範囲で変動する直流電力から交直双方向変換設備４がＰＷＭインバータ構成で３相２００Ｖに変換しようとする場合、図２に示すように、ＰＷＭインバータでは直流をチョッピングしてパルス幅を変調することにより、ＰＷＭ波形の平均値が交流２００Ｖ電圧と一致するように制御する。このとき、交流電圧のピーク値よりも直流電圧が高いことが交流出力に正弦波が得られないことから、直流ラインは最低減でも３００Ｖ前半が要求され、この条件をクリアしたＰＷＭ電力変換を実現することができる。
【００２５】
例えば、３相２００Ｖ系の電圧許容範囲を２２０Ｖ±１０％とする場合、直流電圧の最低値は３４２Ｖ（＝２２０×１．１×√２）となり、３相２００Ｖ系と連系する直流電圧の最低電圧を３４３Ｖよりも高く維持できる４００Ｖ系としておけば、最大電力を供給する太陽光発電設備１から直流電源ラインに直結してその間の電力変換ロスを無くすことができる。
【００２６】
なお、電力変換設備４に変圧器を介挿すれば、直流ラインの電圧条件は広げることができるが、変圧器の電力変換ロスが電源効率を低下させてしまう。
【００２７】
次に、本実施形態のシステムでは、蓄電池設備３や風力発電設備２と自家発電母線との電圧差は、昇降圧チョッパにより調整する。
【００２８】
例えば、蓄電池設備３は２００Ｖにし、自家発電母線との電圧差は昇圧チョッパ３Ａによる昇圧によって整合させる。ここで、蓄電池設備３は２００Ｖに限らないが、自家発電母線電圧が前記のように３３０Ｖ〜４００Ｖになることから、これに近い電圧とするのが好ましい。この理由は、電力変換器３Ａを昇圧チョッパとする場合、図３の回路構成になり、蓄電池設備３からの放電電力はＩＧＢＴ等の半導体スイッチＳＷのオンでリアクトルＬ１に電磁エネルギーとして蓄積し、続いてスイッチＳＷのオフでリアクトルＬ１からダイオードＤ１を通して自家発電母線側に昇圧した出力を得るため、同じ電力量変換でも蓄電池設備３の電圧が低いほどリアクトルＬ１やスイッチＳＷの制御電流が大きくなり、これらでの電力ロスが高くなり、変換効率を下げてしまう。
【００２９】
以上のように、本実施形態によれば、太陽光発電設備を主たる電源とする自家発電系統は、２００Ｖ受電系統に対して、自家発電母線を４００Ｖ系にし、電力容量的に小さい他の風力発電設備や蓄電池設備とは昇降圧チョッパにより結合することで、システム全体からみたチョッパでのロスを最小限にして電源効率を高めることができる。また、システムの直流電圧、要求電力量にマッチしたシステムを実現できる。
【００３０】
なお、本実施形態では、自家発電設備の主たる電源が太陽光発電設備とするシステムに適用した場合を示すが、この主たる電源が出力電圧変動を伴う蓄電池設備、風力発電設備、燃料電池などとするシステムに適用する場合でも当該発電設備を昇降圧チョッパを介することなく自家発電母線に直接接続し、他の発電設備は昇降圧チョッパで電圧調整することにより、同等の作用効果を得ることができる。
【００３１】
（実施形態２）
前記のように、電源システムに使用される蓄電池設備３は、高頻度充放電タイプになり、一般には大電力用として製造されているため、中小型電源システムに対しては容量的に大きすぎるタイプのものしかない。一方、蓄電池のセル当たり電圧は、一般に２Ｖ前後のものが多く、電池容量と自家発電母線電圧と整合させることがしばしば困難となる。
【００３２】
例えば、図１の蓄電池設備３を毎時１０ｋＷで夜間１２時間充電し、昼間に１０時間放電とするシステム運転において、自家発電母線電圧を２００Ｖとすると、放電電流は効率を無視すると、５０Ａ（＝１０ｋＷ×１０００／２００Ｖ）となるのに対して、蓄電池は１０時間×５０Ａ＝５００ＡＨ、１０時間率（定格的に５０Ａを１０時間連続して流すことができる蓄電能力）のものがシステムに整合したものになる。しかし、一般には、高頻度充電用製品の定格は１０００ＡＨ／１０時間率、２０００ＡＨ／１０時間率など電力容量的に大きなものしかない。
【００３３】
また、自家発電母線電圧を２００Ｖとした場合、必要な電圧を得るためには、蓄電池の電池１個当たり２Ｖなので、蓄電池は１００セル（１００個直列）構成になり、一般品の中で小さい方の容量１０００ＡＨを選定したとしても、電力容量は２０ｋＷ（＝１００Ａ×２００Ｖ）となり、必要容量の２倍もの容量となる。
【００３４】
そこで、本実施形態では、電力容量が要求されるものよりも大きい蓄電池を使用する場合、セル数を少なくした蓄電池設備とすることで、電力容量でシステムに整合させる。
【００３５】
例えば、１０００ＡＨ／１０時間の蓄電池を使用する場合、セル数を５０セルに半減した蓄電池設備とする。このとき、
１０００ＡＨ／１０時間×５０セル×２Ｖ＝１００Ａ×１００Ｖ＝１０ｋＷ
となり、前記の要求される電力容量と整合させることができる。この場合、蓄電池は、セル数を減らした分だけ、自家発電電圧２００Ｖとの間に差が出るため、蓄電池から昇降圧チョッパを利用して差電圧を調整することができる。この電圧調整は、蓄電池電圧が放電経過と共に１００％→５０％→３０％などに低下し、自家発電電圧２００Ｖとの差電圧に変化が生じても昇降圧チョッパで吸収することができる。
【００３６】
したがって、本実施形態によれば、自家発電母線電圧に整合した電力容量をもつ蓄電池を使用できない場合にも、セル数を調整することでシステムが要求する容量に整合し、かつ最適経済化した蓄電池設備を得ることができる。また、セル数の調整により、システムの任意の直流電圧に対応した蓄電池設備を実現できる。この任意の直流電圧に対応できることは、いずれの発電設備を基準にするかの自由度も高めることができる。
【００３７】
なお、本実施形態では５０セルとする場合を示すが、これは既存の蓄電池がもつ容量と、システムが要求する電力容量との関係を基に適宜変更することができる。また、蓄電池設備に適用した場合を示すが、太陽光発電設備や風力発電設備での直列数についてもシステムが要求する容量に整合させることができる。
【００３８】
（実施形態３）
図４は、本発明の実施形態を示すシステム構成図である。同図が図１と異なる部分は、自家発電系統の直流母線から直流−直流電力変換器（昇降圧チョッパ）６を通して、受電系統の直流負荷母線に直接に給電する構成にある。
【００３９】
図示のように、受電系統に直流負荷７がある場合、受電系統では受電母線から降圧トランス８と交流−直流電力変換器９を通して直流負荷７へ電力供給する電源構成としており、図１の構成では自家発電系統からの供給電力を電力変換設備４を通して一旦交流電力に変換し、受電系統の電力変換器９で再び直流電力に変換して直流負荷７に供給することになる。
【００４０】
そこで、本実施形態では、自家発電系統の直流母線から電力変換器６を通して直接に直流負荷７に電力供給する構成とすることで、電力変換設備４等を介挿することによる電力変換ロスを無くし、電源効率を高める。
【００４１】
（実施形態４）
前記までの実施形態において、自家発電設備１、２、３等は、それらに異常が発生した場合に自家発電系統から切り離しできるよう、自家発電母線との間に開閉器を設けたシステム構成を示す。
【００４２】
本実施形態では、自家発電設備の殆どが母線との間に昇圧／降圧チョッパを設けるため、このチョッパをシステムとの間を切り離すための開閉器として利用する。例えば、昇圧チョッパ３Ａを蓄電池設備の電源線短絡、過充電防止、過放電防止のために開放制御する。この場合、昇圧チョッパ３Ａが半導体スイッチであるため、ミリ秒オーダの高速遮断が可能となり、半導体遮断器特有の短絡耐量からみた機器の小型化、軽量化も併せて実現できる。結果として、システム構成およびコントローラを簡略化、コストダウンを図ることができる。
【００４３】
【発明の効果】
以上のとおり、本発明によれば、自家発電設備母線を直流系としその直流電圧をシステム容量的に最適な値に設定し、各発電設備毎にシステム電圧に整合させる昇降圧チョッパを組み込み結合したため、容量、電圧、電源効率の上で合理的な電源システムを構築できる。
【図面の簡単な説明】
【図１】本発明の実施形態１を示す電源システムの構成図。
【図２】ＰＷＭインバータの入出力電圧波形。
【図３】昇圧チョッパの回路例。
【図４】本発明の実施形態３を示す電源システムの構成図。
【図５】従来のシステム構成図。
【符号の説明】
１…太陽光発電設備
２…風力発電設備
３…蓄電池設備
４…双方向電力変換設備
５…コントローラ
６、９…電力変換器
７…直流負荷
８…降圧トランス[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a private power generation system in which a storage battery facility and a plurality of types of private power generation facilities (photovoltaic power generation facilities, wind power generation facilities, engine generators, micro gas turbine generators, fuel cells, etc.) are connected to a commercial power supply. Power system.
[0002]
[Prior art]
For example, this type of power supply system stores inexpensive nighttime power and power generated by private power generation equipment in a storage battery facility at night when the load power is relatively small, and stores the power in the daytime when the load power increases. By discharging the stored power and the power generated by the in-house power generation system to the power receiving system, load leveling of the power system, reduction of power charges, measures against uninterruptible power, improvement of power supply efficiency, effective use of natural energy, and the like are enabled.
[0003]
FIG. 5 shows a configuration example of a conventional power supply system. A private power generation system that can be connected to a power receiving system from a commercial power supply connects a photovoltaic power generation facility 1, a wind power generation facility 2, and a storage battery facility 3 for storing nighttime power to a DC private power generation bus. The private power generation system and the commercial power supply are interconnected by power conversion by the AC / DC bidirectional power conversion equipment 4 to supply power to the load.
[0004]
In such a system configuration, the power generation power of the solar power generation equipment 1 and the wind power generation equipment 2 greatly changes depending on time, season, and weather, and the stabilization and leveling are performed by the power storage by the storage battery equipment 3 and the fuel cell. It can be covered by power generation adjustment. In addition, the photovoltaic power generation facilities and the like generate DC power, and can be connected to the storage battery facility and the fuel cell by a DC system without performing DC-AC power conversion.
[0005]
For example, Japanese Patent Application Laid-Open No. 6-78475 discloses a battery in which a photovoltaic power generator is provided in parallel with a battery and the battery is charged from the photovoltaic power generator through a step-up chopper.
[0006]
In addition, wind power generation equipment, engine generators, micro gas turbine generators, etc. become AC power generation, and when these are incorporated into the system, the generated power is converted to AC-DC power to connect with other DC power generation equipment. Becomes possible.
[0007]
[Problems to be solved by the invention]
As described above, the photovoltaic power generation equipment, the storage battery equipment, and the fuel cell can be DC-coupled without power conversion, but the power generation voltages are different from each other, and require voltage adjustment by a DC-DC power converter such as a chopper. .
[0008]
In addition, the capacity standard of the storage battery equipment is stepwise (for example, 220, 330, 660, 1000 Ah / 10 hr), and the capacity is determined by the number of parallels of the same standard, but it is stepwise. In addition, the DC voltage of the storage battery equipment is determined by the number of cells connected in series, but unlike a storage battery that always charges at a constant voltage in a full state, it is a high-frequency charge / discharge type, and its charge amount and charge amount DC voltage changes greatly.
[0009]
From the above, when trying to combine a plurality of private power generation facilities having different power generation methods, it is difficult to directly couple each other due to differences in capacity and voltage.
[0010]
On the other hand, wind power generation equipment and photovoltaic power generation equipment require a wide range of voltage adjustment because generated power greatly changes depending on wind speed, sunshine, and the like. In addition, these facilities can extract the maximum power when the generated voltage is set to a certain value due to their characteristics, and can extract the maximum power by changing the DC voltage. Attempts to reduce power generation efficiency.
[0011]
As a result, it has been difficult for the various power sources of the in-house power generation facility to construct an effective power source system in terms of capacity, voltage, and power source efficiency in connection with each other.
[0012]
An object of the present invention is to provide a power supply system that solves the above-mentioned problems.
[0013]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention incorporates a step-up / step-down chopper that sets a private power generation facility bus to a DC system, sets the DC voltage to an optimal value in terms of system capacity, and matches the system voltage to each power generation facility. By combining them, a rational power supply system can be constructed, and is characterized by the following configuration.
[0014]
(1) In a power supply system in which a private power generation system combining a storage battery facility and a plurality of types of private power generation facilities is connected to a commercial power supply,
Combining the storage battery facility and the private power generation facility with the bus of the private power generation system as a DC system,
Of the storage battery equipment and the private power generation equipment, the main equipment with a generated power capacity is directly coupled to the DC system to be a DC voltage of the private power generation system,
Another storage battery facility or a private power generation facility is configured to obtain matching with the DC voltage of the private power generation system via a step-up or step-down chopper, respectively.
[0015]
(2) In a power supply system in which a private power generation system combining a storage battery facility and a plurality of types of private power generation facilities is connected to a commercial power supply,
Combining the storage battery facility and the private power generation facility with the bus of the private power generation system as a DC system,
When using a storage battery or a private generator that is larger than the power capacity required by the system, the storage battery facility or private power generation facility reduces the number of cells of the storage battery or the number of private generators connected in series to the power capacity required by the system. In addition, the voltage difference from the DC voltage of the private power generation system is matched by a step-up / step-down chopper.
[0016]
(3) In a power supply system having a DC load, a power converter capable of directly supplying power to the DC load from a DC bus of the private power generation system is provided.
[0017]
(4) The chopper is an opening / closing means for separating the storage battery facility or the private power generation facility from the private power generation bus.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
FIG. 1 is a system configuration diagram showing an embodiment of the present invention. In the private power generation system, a photovoltaic power generation facility 1, a wind power generation facility 2, and a storage battery facility 3 are provided as power generation power sources, and an AC / DC bidirectional power conversion facility 4 is provided. In this case, the private power generation system and the commercial power supply are interconnected.
[0019]
In the present embodiment, the present invention is applied to a case where the photovoltaic power generation equipment is the main power supply in terms of electric power capacity, and the power receiving system is a three-phase 200 V system, whereas the bus voltage of the private power generation system is DC 400 V. . In accordance with this, the other private power generation facilities (the wind power generation facility 2 and the storage battery facility 3 in the figure) have a configuration in which a power converter matched with the DC bus voltage is combined. This power converter is a power converter 2A configured by a rectifier and a buck-boost chopper in the wind power generation facility 2, and a power converter 3A configured by a buck-boost chopper in the storage battery facility 3.
[0020]
The controller 5 generates an operation command from the operation command unit 5A to the power conversion control units 5B, 5C, 5D, controls power conversion of the power converters 2A, 3A by the control units 5B, 5C, and controls the power conversion by the control unit 5D. The power interchange control of the conversion equipment 4 is performed. These controls are calculated based on detection signals such as the output current and voltage of the control target. The control unit 5E is for the case where the power converter 1A is interposed in the photovoltaic power generation equipment 1 and the wind power generation equipment 2 to perform the maximum power tracking control.
[0021]
As described above, the photovoltaic power generation equipment 1 serving as a main power source is directly connected to a 400 V DC line without using a buck-boost chopper, and the wind power generation equipment 2 serving as another power generation equipment is connected through a buck-boost chopper 2A including a rectifier. It is connected to a DC 400V line, and the storage battery equipment 3 is connected to the DC 400V line through a step-up / step-down chopper 3A.
[0022]
With such a system configuration, in the present embodiment, an effective power supply system can be obtained in terms of capacity, voltage, and power supply efficiency. The reason will be described in detail below.
[0023]
In the case of a photovoltaic power generation facility, the DC voltage at which the maximum power can be extracted by sunshine changes greatly. Therefore, the generated voltage is not always 400 V, and depending on the amount of solar radiation, the maximum power may be extracted when the DC voltage is in the first half of 300 V. Further, in the sense of fluctuation of the DC voltage, the discharge of the storage battery facility 3 greatly reduces the DC 400 V line serving as the private power generation bus.
[0024]
Therefore, the DC 400 V line actually fluctuates between the first half of 300 V and 400 V. When the AC / DC bidirectional conversion equipment 4 intends to convert the DC power fluctuating in this voltage range into three-phase 200V in a PWM inverter configuration, the PWM inverter modulates the pulse width by chopping the DC, as shown in FIG. Thus, control is performed so that the average value of the PWM waveform matches the AC 200 V voltage. At this time, since the DC voltage is higher than the peak value of the AC voltage, a sine wave cannot be obtained in the AC output. can do.
[0025]
For example, when the allowable voltage range of the three-phase 200V system is set to 220V ± 10%, the minimum value of the DC voltage is 342V (= 220 × 1.1 × √2). With a 400 V system capable of maintaining the minimum voltage higher than 343 V, it is possible to directly connect the solar power generation facility 1 that supplies the maximum power to the DC power supply line and eliminate power conversion loss during the connection.
[0026]
In addition, if a transformer is inserted in the power conversion equipment 4, the voltage condition of the DC line can be widened, but the power conversion loss of the transformer lowers the power supply efficiency.
[0027]
Next, in the system of the present embodiment, the voltage difference between the storage battery facility 3 or the wind power generation facility 2 and the private power generation bus is adjusted by a step-up / step-down chopper.
[0028]
For example, the voltage of the storage battery equipment 3 is set to 200 V, and the voltage difference from the private power generation bus is matched by boosting by the boosting chopper 3A. Here, the storage battery equipment 3 is not limited to 200 V, but since the private power generation bus voltage is 330 V to 400 V as described above, it is preferable to set the voltage close to this. The reason is that when the power converter 3A is a step-up chopper, the circuit configuration is as shown in FIG. 3, and the discharge power from the storage battery facility 3 is stored as electromagnetic energy in the reactor L1 when the semiconductor switch SW such as IGBT is turned on. In order to obtain an output boosted from the reactor L1 to the private power generating bus side through the diode D1 when the switch SW is turned off, the control current of the reactor L1 and the switch SW increases as the voltage of the storage battery equipment 3 decreases even with the same power conversion. The power loss in the system increases, and the conversion efficiency decreases.
[0029]
As described above, according to the present embodiment, the private power generation system using the solar power generation facility as a main power source is different from the 200 V power receiving system in that the private power generation bus is a 400 V system, and other wind power By coupling to the equipment and the storage battery equipment by the step-up / step-down chopper, it is possible to minimize the loss in the chopper from the viewpoint of the entire system and to improve the power supply efficiency. Further, a system that matches the DC voltage and the required power amount of the system can be realized.
[0030]
In the present embodiment, a case where the main power supply of the private power generation equipment is applied to a system in which the photovoltaic power generation equipment is used is shown. However, the main power supply is a storage battery equipment, a wind power generation equipment, a fuel cell, or the like with output voltage fluctuation. Even when applied to a system, the same function and effect can be obtained by directly connecting the power generation equipment to the private power generation bus without using a buck-boost chopper and adjusting the voltage of the other power generation equipment by the buck-boost chopper.
[0031]
(Embodiment 2)
As described above, the storage battery equipment 3 used in the power supply system is of a high-frequency charge / discharge type, and is generally manufactured for high power. There are only things. On the other hand, the voltage per cell of the storage battery is generally around 2 V, and it is often difficult to match the battery capacity with the private power generation bus voltage.
[0032]
For example, in a system operation in which the storage battery facility 3 of FIG. 1 is charged at 10 kW / hour for 12 hours at night and discharged for 10 hours during the day, if the private power generation bus voltage is 200 V, the discharge current is 50 A (= 10 kW, ignoring the efficiency). X 1000 / 200V), while the storage battery is 10 hours x 50A = 500AH, 10 hour rate (power storage capacity that can continuously flow 50A for 10 hours continuously) matches the system become. However, in general, high-frequency charging products have only a large power capacity such as a 1000 AH / 10 hour rate and a 2000 AH / 10 hour rate.
[0033]
In addition, when the private power generation bus voltage is set to 200 V, in order to obtain a required voltage, since each battery of the storage battery is 2 V, the storage battery has a configuration of 100 cells (100 cells in series). Even if a capacity of 1000 AH is selected, the power capacity is 20 kW (= 100 A × 200 V), which is twice the required capacity.
[0034]
Therefore, in the present embodiment, when a storage battery having a power capacity larger than that required is used, a storage battery facility having a reduced number of cells is used to match the system with the power capacity.
[0035]
For example, in the case of using a storage battery of 1000 AH / 10 hours, the storage battery facility is halved to 50 cells. At this time,
1000 AH / 10 hours × 50 cells × 2 V = 100 A × 100 V = 10 kW
, And can be matched with the required power capacity. In this case, since the difference between the storage battery and the self-generated voltage of 200 V is produced by the reduced number of cells, the difference voltage can be adjusted from the storage battery by using the step-up / step-down chopper. This voltage adjustment can be absorbed by the step-up / step-down chopper even if the storage battery voltage decreases from 100% to 50% to 30% or the like as the discharge proceeds, and the voltage difference from the self-generated voltage 200V changes.
[0036]
Therefore, according to the present embodiment, even when a storage battery having a power capacity matched to the private power generation bus voltage cannot be used, the storage battery is adjusted to the capacity required by the system by adjusting the number of cells, and is optimally economical. Equipment can be obtained. Further, by adjusting the number of cells, it is possible to realize a storage battery facility corresponding to an arbitrary DC voltage of the system. Being able to cope with this arbitrary DC voltage can increase the degree of freedom as to which power generation equipment is used as a reference.
[0037]
In this embodiment, the case where the number of cells is 50 is shown, but this can be changed as appropriate based on the relationship between the capacity of the existing storage battery and the power capacity required by the system. Although the case where the present invention is applied to a storage battery facility is shown, the number of series in a solar power facility or a wind power facility can be matched to the capacity required by the system.
[0038]
(Embodiment 3)
FIG. 4 is a system configuration diagram showing an embodiment of the present invention. 1 differs from FIG. 1 in the configuration in which power is supplied directly from the DC bus of the private power generation system to the DC load bus of the power receiving system through a DC-DC power converter (step-up / step-down chopper) 6.
[0039]
As shown in the drawing, when the power receiving system has a DC load 7, the power receiving system has a power supply configuration for supplying power from the power receiving bus to the DC load 7 through the step-down transformer 8 and the AC-DC power converter 9. The power supplied from the private power generation system is once converted into AC power through the power conversion equipment 4, converted into DC power again by the power converter 9 in the power receiving system, and supplied to the DC load 7.
[0040]
Therefore, in the present embodiment, the power is directly supplied to the DC load 7 from the DC bus of the private power generation system through the power converter 6, thereby eliminating the power conversion loss caused by interposing the power conversion equipment 4 or the like. , Increase power efficiency.
[0041]
(Embodiment 4)
In the embodiments described above, the private power generation facilities 1, 2, 3 and the like show a system configuration in which a switch is provided between the private power generation bus so that they can be separated from the private power generation system when an abnormality occurs in them. .
[0042]
In the present embodiment, most of the private power generation equipment has a step-up / step-down chopper between itself and the bus, so this chopper is used as a switch for disconnecting the chopper from the system. For example, the boosting chopper 3A is controlled so as to be open in order to prevent short-circuiting of the power supply line of the storage battery equipment, prevention of overcharge, and prevention of overdischarge. In this case, since the step-up chopper 3A is a semiconductor switch, high-speed interruption on the order of milliseconds is possible, and downsizing and weight reduction of the device can be realized in view of the short-circuit withstand characteristic of the semiconductor circuit breaker. As a result, the system configuration and the controller can be simplified and the cost can be reduced.
[0043]
【The invention's effect】
As described above, according to the present invention, the private power generation equipment bus is set to a DC system, the DC voltage is set to an optimum value in terms of system capacity, and a buck-boost chopper that matches the system voltage for each power generation equipment is incorporated and coupled. A reasonable power supply system can be constructed in terms of capacity, voltage and power supply efficiency.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a power supply system according to a first embodiment of the present invention.
FIG. 2 is an input / output voltage waveform of a PWM inverter.
FIG. 3 is a circuit example of a boost chopper.
FIG. 4 is a configuration diagram of a power supply system according to a third embodiment of the present invention.
FIG. 5 is a configuration diagram of a conventional system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Solar power generation equipment 2 ... Wind power generation equipment 3 ... Battery storage equipment 4 ... Bidirectional power conversion equipment 5 ... Controller 6, 9 ... Power converter 7 ... DC load 8 ... Step-down transformer

Claims (4)

蓄電池設備と複数種の自家発電設備とを結合した自家発電系統を商用電源と連系させる電源システムにおいて、
前記自家発電系統の母線を直流系として前記蓄電池設備および自家発電設備を結合し、
前記蓄電池設備及び自家発電設備のうち、発電電力容量で主となる設備を前記直流系に直接に結合して自家発電系統の直流電圧とし、
他の蓄電池設備または自家発電設備はそれぞれ昇圧または降圧チョッパを介して自家発電系統の直流電圧との整合を得る構成としたことを特徴とする電源システム。In a power supply system that links a private power generation system that combines a storage battery facility and a plurality of types of private power generation facilities with a commercial power supply,
Combining the storage battery facility and the private power generation facility with the bus of the private power generation system as a DC system,
Of the storage battery facility and the private power generation facility, the facility mainly equipped with a generated power capacity is directly connected to the DC system to be a DC voltage of the private power generation system,
A power supply system wherein another storage battery facility or a private power generation facility is configured to obtain matching with a DC voltage of a private power generation system via a step-up or step-down chopper, respectively. 蓄電池設備と複数種の自家発電設備とを結合した自家発電系統を商用電源と連系させる電源システムにおいて、
前記自家発電系統の母線を直流系として前記蓄電池設備および自家発電設備を結合し、
前記蓄電池設備または自家発電設備は、システムが要求する電力容量よりも大きい蓄電池または自家発電機を使用する場合、蓄電池のセル数または自家発電機の直列接続台数を減らしてシステムが要求する電力容量に合わせ、自家発電系統の直流電圧との電圧差は昇圧／降圧チョッパで整合させることを特徴とする電源システム。In a power supply system that links a private power generation system that combines a storage battery facility and a plurality of types of private power generation facilities with a commercial power supply,
Combining the storage battery facility and the private power generation facility with the bus of the private power generation system as a DC system,
When using a storage battery or a private generator that is larger than the power capacity required by the system, the storage battery facility or private power generation facility reduces the number of cells of the storage battery or the number of private generators connected in series to the power capacity required by the system. In addition, a voltage difference from the DC voltage of the private power generation system is matched by a step-up / step-down chopper. 直流負荷をもつ電源システムにおいて、前記自家発電系統の直流母線から前記直流負荷に直接に電力供給できる電力変換器を設けたことを特徴とする請求項１または２に記載の電源システム。3. The power supply system according to claim 1, wherein a power converter capable of directly supplying power from the DC bus of the private power generation system to the DC load is provided in the power supply system having a DC load. 4. 前記チョッパは、前記蓄電池設備または自家発電設備と自家発電母線との切り離しのための開閉手段としたことを特徴とする請求項１〜３のいずれか１項に記載の電源システム。The power supply system according to any one of claims 1 to 3, wherein the chopper is an opening / closing unit for separating the storage battery facility or the private power generation facility from the private power generation bus.
JP2002246149A 2002-08-27 2002-08-27 Power supply system Pending JP2004088900A (en)

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JP2008148485A (en) * 2006-12-12 2008-06-26 Nippon Telegr & Teleph Corp <Ntt> Method of designing power supply system
WO2009076640A2 (en) * 2007-12-12 2009-06-18 Pareto Energy Ltd. Electric power distribution methods and apparatus
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JP2012010502A (en) * 2010-06-25 2012-01-12 Sansha Electric Mfg Co Ltd Charge and discharge device for storage battery
JP2013511946A (en) * 2009-11-24 2013-04-04 エスエムエー ソーラー テクノロジー アーゲー Photovoltaic array startup with high open-circuit voltage
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JP2008148485A (en) * 2006-12-12 2008-06-26 Nippon Telegr & Teleph Corp <Ntt> Method of designing power supply system
US8183714B2 (en) 2007-12-12 2012-05-22 Mcdonnell Alan Electric power distribution methods and apparatus
WO2009076640A2 (en) * 2007-12-12 2009-06-18 Pareto Energy Ltd. Electric power distribution methods and apparatus
WO2009076640A3 (en) * 2007-12-12 2009-09-11 Pareto Energy Ltd. Electric power distribution methods and apparatus
CN101919135A (en) * 2007-12-12 2010-12-15 佩尔托能源有限公司 Electric power distribution methods and apparatus
JP2010074997A (en) * 2008-09-19 2010-04-02 Toyota Motor Corp Building and method for selecting power supply route
WO2010066105A1 (en) * 2008-12-12 2010-06-17 无锡开普动力有限公司 Hybrid direct current power supply control system for communication station
WO2010082981A2 (en) 2009-01-16 2010-07-22 Zbb Energy Corporation Method and apparatus for controlling a hybrid power system
WO2010082981A3 (en) * 2009-01-16 2010-09-16 Zbb Energy Corporation Method and apparatus for controlling a hybrid power system
US8981708B2 (en) 2009-08-19 2015-03-17 Aloys Wobben Electrical charging apparatus
JP2013511946A (en) * 2009-11-24 2013-04-04 エスエムエー ソーラー テクノロジー アーゲー Photovoltaic array startup with high open-circuit voltage
JP2011139556A (en) * 2009-12-28 2011-07-14 Hitachi Industrial Equipment Systems Co Ltd Power supply system
CN101841163A (en) * 2010-03-15 2010-09-22 三一电气有限责任公司 Grid-connected wind-light combined power generation system and power generation method thereof
DE102010022043A1 (en) * 2010-05-26 2011-12-01 Siemens Aktiengesellschaft Energy storage in the field of electrical energy transmission and distribution
JP2012010502A (en) * 2010-06-25 2012-01-12 Sansha Electric Mfg Co Ltd Charge and discharge device for storage battery
CN102130507A (en) * 2011-03-26 2011-07-20 河南省电力公司 Intelligent home system accessing to intelligent power gird and new energy and energy efficiency managing method
JP2013243894A (en) * 2012-05-22 2013-12-05 Sony Corp Control system, control device, and control method
CN104303392A (en) * 2012-05-22 2015-01-21 索尼公司 Control system
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JPWO2013175702A1 (en) * 2012-05-22 2016-01-12 ソニー株式会社 Control system
WO2015098011A1 (en) * 2013-12-24 2015-07-02 パナソニックＩｐマネジメント株式会社 Power conversion system, converter device, inverter device, and power conversion system manufacturing method
JP2015122885A (en) * 2013-12-24 2015-07-02 パナソニックＩｐマネジメント株式会社 Power conversion system, converter device, inverter device, and method of manufacturing power conversion system
JP2015092824A (en) * 2015-01-13 2015-05-14 京セラ株式会社 Power conditioner and method for controlling power conditioner
KR101836230B1 (en) * 2016-04-14 2018-03-09 금오공과대학교 산학협력단 System and method ofoperating variable voltage for DC micro-grid
US11192465B2 (en) 2017-04-21 2021-12-07 Wobben Properties Gmbh Charging station for charging multiple electric vehicles, in particular electric cars

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