JP3598799B2

JP3598799B2 - Uninterruptible power system

Info

Publication number: JP3598799B2
Application number: JP4308498A
Authority: JP
Inventors: 修司田村
Original assignee: Shin Kobe Electric Machinery Co Ltd
Current assignee: Resonac Corp
Priority date: 1998-02-25
Filing date: 1998-02-25
Publication date: 2004-12-08
Anticipated expiration: 2018-02-25
Also published as: JPH11252826A

Description

【発明の属する技術分野】
本発明は、無停電電源装置における負荷への給電方式の切り換えに関するものである。
【従来の技術】
従来から使用されている商用電源を用いた無停電電源装置を大別すると、常時インバータで給電をする方式（オンライン方式）と、常時商用電源で給電をする方式（オフライン方式）がある。そして、どちらの方式を選択するかについては、ａ）商用電源の質、ｂ）使用する負荷の電圧変動許容値、ｃ）コストなどに応じて使い分けがされている。なお、オンライン方式及びオフライン方式の無停電電源装置の一般的な回路ブロック図を図４に示す。オンライン方式もオフライン方式も、ほぼ同じ回路構成である。すなわち、商用電源１１の交流電圧を整流器１２によって直流電圧に変換し、インバータ１４の入力又は鉛蓄電池１３の充電に用いる。整流器１２または鉛蓄電池１３からの電力はインバータ１４に供給する。そして、商用電源１１の電力をそのまま負荷１６へ供給するか、それともインバータ１４の出力を負荷１６へ供給するかについては、電源切換スイッチ１５によって切り換える。なお、オンライン方式又はオフライン方式は、それぞれ以下に示すような特徴がある。
オンライン方式は、常時はインバータ１４を運転し、負荷１６に電力を供給する方式である。そして、インバータ１４からの出力が過大になった場合やインバータ１４の故障時等に、電源切換スイッチ１５を用いてインバータ給電から、商用電源給電に切り換える。すなわち、オンライン方式では常時インバータ給電をしているため、安定した電圧を負荷１６に供給することが可能である。したがって、商用電源電圧の変動が多い場所や、電圧変動許容値が少ない負荷等に主に使用されている。しかしながら、整流器１２はインバータ１４への給電と鉛蓄電池１３の充電を同時に行う為、大きな容量が必要となりコストも高いものになる。さらに、インバータ１４や整流器１２による発熱を抑える為、大形の冷却ファンが必要となり、その結果騒音が大きくなるなどの問題がある。したがって、オンライン方式を用いると、大形の冷却ファンの使用による換気口の目詰まりや、内部の埃等の蓄積が多いことから定期的な保守点検が必要であるという問題点もある。
一方、オフライン方式は、常時は商用電源１１の電圧を負荷１６に給電する方式である。そして、停電時や商用電源１１の電圧の異常時にインバータ１４を運転し、電源切換スイッチ１５を切り換えて負荷１６に電力を供給する。また、常時はインバータ１４を運転しないため、省エネであることや冷却ファンによる騒音がないこと、換気口の目詰まりが少ない等のメリットがある。しかしながら、オフライン方式の無停電電源装置を電源事情が悪い環境で使用される場合は、インバータ給電と商用給電が頻繁に繰り返すことになる。したがって、使用する蓄電池の放電深度が多くなり、その結果、蓄電池の寿命が短いという問題点がある。なお、商用電源の電源事情を確認するためには、現地において電圧計、オシロスコープ及びデータレコーダ等による長期間の測定が必要となり、手間と費用が掛かるという問題点がある。
【発明が解決しようとする課題】
本発明の目的は、商用電源の環境を事前に確認する必要が無く、商用電源の変動状況に応じて自動的にオンライン方式とオフライン方式を切り換えることが可能な無停電電源装置を提供することである。
【課題を解決するための手段】
上記課題を解決するために、第一の発明では、商用電源の交流電圧を直流電圧に変換してインバータ及び蓄電池に供給する整流器、直流電圧を交流電圧に変換するインバータ、インバータに直流電圧を供給する蓄電池、商用電源の交流電圧を監視する商用電源監視回路、商用電源から負荷への給電又はインバータから負荷への給電のいずれかに切り換えるための電源切換スイッチを有する無停電電源装置において、あらかじめ設定した監視期間における商用電源の電圧異常の発生回数が所定の基準値よりも大きい場合には、インバータと電源切換スイッチに、オフライン方式からオンライン方式に切り換える信号を出力し、あらかじめ設定した監視期間における商用電源の電圧異常の発生回数が所定の基準値よりも小さい場合には、インバータと電源切換スイッチに、オンライン方式からオフライン方式に切り換える信号を出力する電源切換制御部を有することを特徴としている。
第二の発明では、第一の発明における電源切換制御部は、商用電源の周波数、位相、波形の異常の発生回数があらかじめ設定した監視期間における所定の基準値よりも大きい場合には、インバータと電源切換スイッチに、オフライン方式からオンライン方式に切り換える信号を出力し、商用電源の周波数、位相、波形の異常の発生回数があらかじめ設定した監視期間における所定の基準値よりも小さい場合には、インバータと電源切換スイッチに、オンライン方式からオフライン方式に切り換える信号を出力する電源切換制御部を有することを特徴としている。
第三の発明では、第一又は第二の発明における電源切換制御部は、前記商用電源の監視期間及び電圧、周波数、位相、波形のいずれかについて、異常の発生回数の基準値を外部設定回路によって設定できるものであることを特徴としている。
第四の発明では、商用電源の交流電圧を直流電圧に変換してインバータ及び蓄電池に供給する整流器、直流電圧を交流電圧に変換するインバータ、インバータに直流電圧を供給する蓄電池、商用電源の交流電圧を監視する商用電源監視回路、蓄電池の放電深度を監視する回路、商用電源から負荷への給電又はインバータから負荷への給電のいずれかに切り換えるための電源切換スイッチを有する無停電電源装置において、前記蓄電池の放電深度を監視する回路によって蓄電池の放電深度が基準値よりも高いと判定した場合には、インバータと電源切換スイッチに、オンライン方式からオフライン方式に切り換える信号を出力し、蓄電池の放電深度が基準値よりも低いと判定した場合には、インバータと電源切換スイッチに、オフライン方式からオンライン方式に切り換える信号を出力する電源切換制御部を有することを特徴としている。
第五の発明では、第四の発明における電源切換制御部は、蓄電池の監視期間、放電深度の基準値を外部設定回路によって設定できるものであることを特徴としている。
第六の発明では、商用電源の交流電圧を直流電圧に変換してインバータ及び蓄電池に供給する整流器、直流電圧を交流電圧に変換するインバータ、インバータに直流電圧を供給する蓄電池、商用電源の交流電圧を監視する商用電源監視回路、蓄電池の放電深度を監視する回路、商用電源から負荷への給電又はインバータから負荷への給電のいずれかに切り換えるための電源切換スイッチを有する無停電電源装置において、あらかじめ設定した監視期間における商用電源の電圧異常の発生回数が所定の基準値よりも大きく、かつ該蓄電池の放電深度を監視する回路によって蓄電池の放電深度が基準値よりも高いと判定した場合には、インバータと電源切換スイッチに、オフライン方式からオンライン方式に切り換える信号を出力し、あらかじめ設定した監視期間における商用電源の電圧異常の発生回数が所定の基準値よりも小さく、かつ該蓄電池の放電深度を監視する回路によって蓄電池の放電深度が基準値よりも高いと判定した場合には、インバータと電源切換スイッチに、オンライン方式からオフライン方式に切り換える信号を出力する電源切換制御部を有することを特徴としている。
第七の発明では、第六の発明における電源切換制御部は、商用電源の監視期間、電圧、周波数、位相、波形のいずれかについて異常の発生回数の基準値と、蓄電池の監視期間、放電深度の基準値とを外部設定回路によって設定できるものであることを特徴としている。
【実施例】
以下に、本発明の一実施例を説明する。図１は本発明の装置のブロック図、図２、３はフローチャートを示す。
図１において、本発明は大きく分けると主回路部５０と制御回路部５１で構成される。なお、主回路部５０は以下の動作をする回路で構成される。すなわち、商用電源１１の交流を整流器１２で直流に変換し、シャント７を通して鉛蓄電池１３の充電及び、インバータ１４へ電力を供給する。そして、電源切換スイッチ１５は、後述する制御回路部５１の電源切換スイッチ制御回路６からの信号によって、負荷１６に供給する電力について商用電源１１をバイパスさせて出力するか、またはインバータ１４より出力するかを切り換える装置である。
一方、制御回路部５１は大きく分けると、商用電源監視部５２、鉛蓄電池監視部５３、電源切換制御部５４より構成されている。商用電源監視部５２は、商用電源１１の電圧、周波数、波形、位相を検出してその内容を電源切換制御部５４へ出力する回路部である。周波数検出回路２１で商用電源１１の周波数に異常があるか否かを検出する。波形検出回路２２で商用電源１１の波形及び位相を検出する。商用電源１１の電圧は、低電圧Ａ検出回路２３、過電圧Ａ検出回路２４、低電圧Ｂ検出回路２５、過電圧Ｂ検出回路２６で検出する。
鉛蓄電池監視部５３は、鉛蓄電池１３の電圧を検出する電圧検出回路７１と、充放電電流を検出するシャント７及び電流検出回路７２と、これらの回路で測定されたデータから鉛蓄電池の放電深度を計算する充放電検出回路７３より構成される。
電源切り換え制御部５４は、商用電源監視部５２から出力される商用電源の変動及び鉛蓄電池監視部５３から出力される鉛蓄電池１３の放電深度の関係から、オフライン方式とオンライン方式の切り換えを制御する部分である。なお、外部設定回路８は、後述する商用電源電圧の異常及び、鉛蓄電池放電深度の監視期間や判定内容について手動で再設定ができるようにしたものである。
本装置の商用電源監視部５２について、フローチャートを図２に示す。Ｓ１１において、商用電源電圧の取り込みをする。
Ｓ２１以下のステップは、商用電源の交流電圧の周波数と位相差を計測する。Ｓ２２において、計測した商用電源の周波数が（本実施例では、周波数５０Ｈｚを定格とする。）４８〜５２Ｈｚの範囲内であれば周波数正常としてＳ２３へ行き、この範囲外の場合には周波数異常としてＳ２５へ行きオンライン方式を指示するように記憶する。Ｓ２３において、商用電源の交流電圧の位相差が５°以内であれば正常としてＳ２４にてオフライン方式を指示するように記憶し、位相差が５°を越える場合は異常としてＳ２５へ行きオンライン方式を指示するように記憶する。
Ｓ３１以下のステップは、商用電源の交流電圧の実効値を計測し、判定・記憶する部分である。Ｓ３２において、交流電圧の実効値が９０Ｖ未満であればＳ３３へ行き、９０Ｖ以上であればＳ３４へ行く。Ｓ３３において、交流電圧の実効値が８０〜９０Ｖの範囲内であればＳ５１へ行き低電圧Ａと判定してデータを記億する。一方、交流電圧の実効値が８０〜９０Ｖの範囲外であればＳ５２へ行き８０Ｖ以下であるとして低電圧Ｂと判定してデータを記億する。Ｓ３４において、交流電圧の実効値が１１０Ｖを越える場合はＳ３５へ行き、１１０Ｖ以下の場合は（すなわち９０〜１１０Ｖの場合）はＳ３６へ行き電圧正常と判断する。Ｓ３５において、交流電圧の実効値が１１０〜１２０Ｖの範囲内であればＳ５３へ行き過電圧Ａと判定してデータを記億しておく。一方、交流電圧の実効値が１１０〜１２０Ｖの範囲外（１２０Ｖ以上）であればＳ５４へ行き過電圧Ｂと判定してデータを記億する。すなわち、交流電圧の実効値の範囲が９０Ｖ以下または１１０Ｖ以上の範囲では、電圧状況によってＳ５１〜Ｓ５４に記憶される値は異なるものの、全体としてはオンライン方式を指示するようにＳ５６に記憶する。
Ｓ４１以下のステップは、商用電源の波形を計測する部分である。Ｓ４２において、交流電圧のピーク値が１１０Ｖ未満の場合はＳ５５へ行き瞬時停電と判定し、１１０Ｖ以上であった場合はＳ４３へ行く。Ｓ４３において、商用電源の電圧波形の瞬断時間が２ｍｓ（０．００２秒）以上の場合は、Ｓ５５へ行き瞬時停電と判定し、２ｍｓ未満の場合はＳ４４へ行き電圧波形が正常であると判定する。したがって、電圧波形が正常である場合にはＳ４６においてオフライン方式を指示するように記憶し、異常である場合にはＳ５６においてオンライン方式を指示するように記憶する。
次に、無停電電源装置をオフライン方式で運転するか、またはオンライン方式で運転するかの切り換えをする、オンライン／オフライン判定回路３の動作について、図３に示すフローチャートを用いて説明する。この部分は、商用電源１１の変動や鉛蓄電池１３の放電深度の状況によって、オフライン方式を用いるか、オンライン方式を用いるかの判断をする部分である。
Ｓ６１において初期動作を確認した後、無停電電源装置の立ち上げ時はオフライン方式を設定する。Ｓ６２において、商用電源１１の監視期間を設定する。オフライン方式からオンライン方式に切り換えるための判定期間をＴF1とし、その復帰条件であるオンライン方式からオフライン方式に切り換えるための判定期間をＴF2とする。本実施例ではＴF1を１ヶ月、ＴF2を１日として設定した。前記したように、なるべくオフライン方式で運転したいため、商用電源１１の電圧が１日程度安定すれば、オフライン方式を指示するようにした。
Ｓ６３は、商用電源１１の監視結果から、オンライン／オフライン方式の切り換えの基準値を設定するステップである。商用電源１１の異常発生回数について、オフライン方式からオンライン方式に切り換えるための基準値をＧF1とし、オンライン方式からオフライン方式に切り換えるための復帰条件の基準値をＧF2とする。本実施例では、ＧF1は１０回、ＧF2は１回とした。そして、Ｓ６２、Ｓ６３から、1ヶ月（ＴＦ１）で１０回（ＧＦ１）異常が発生し、かつ、そのうち1日（ＴＦ２）で１回（ＧＦ２）以上の異常が発生した場合にはオフライン方式からオンライン方式に切り換えるよう指示することにした。すなわち、商用電源１１の異常が短い期間で頻繁に発生したときのみ、オフライン方式からオンライン方式に切り換えるようにした。
Ｓ６４において、鉛蓄電池の放電深度の監視期間を設定する。まずオフライン方式からオンライン方式に切り換えるための監視期間をＴB1とし、その復帰条件であるオンライン方式からオフライン方式に切り換えるための監視期間をＴB2とする。本実施例では、ＴB1は１ヶ月、ＴB2は１日として設定した。
Ｓ６５において、無停電電源装置のオンライン／オフライン方式、切り換えの基準値を設定する。オフライン方式からオンライン方式に切り換えるための鉛蓄電池放電深度の基準値をＧB1とし、オンライン方式からオフライン方式に切り換えるための復帰条件をＧB2とする。本実施例では、ＧB1は２０％、ＧB2は５％とする。すなわち、オフライン方式では商用電源１１の電圧は安定していると想定し、鉛蓄電池の放電深度が比較的高くても問題は少ないとした。なお、放電深度が５０％とは、満充電時における鉛蓄電池の容量の半分が放電した状態である。
Ｓ６６において、商用電源監視回路５２で記憶（図２のフローチャートで記述）したデータを読み込む。一方、Ｓ６７において、鉛蓄電池監視部５３で記憶した鉛蓄電池の放電深度のデータを読み込む。Ｓ６８において、現在オフライン方式で運転中であるか、オンライン方式で運転中であるかを確認し、オフライン方式で運転中であればＳ７１へ行き、オンライン方式で運転中であればＳ８１へ行く。Ｓ７１において、商用電源１１の電圧変動と鉛蓄電池の放電深度が、設定した基準値の範囲内か否か、すなわち、オフライン方式からオンライン方式へ切り換える必要があるか否かを判断する。一方、Ｓ８１において、商用電源１１の電圧変動と鉛蓄電池の放電深度が、設定した基準値の範囲内か否か、すなわち、オンライン方式からオフライン方式へ切り換える必要があるか否かを判断する。これらの判断結果から、それぞれＳ７２でオフライン方式、Ｓ８２でオンライン方式を選択する。無停電電源装置の出力方式を切り換える場合には、インバータ制御回路５及び電源切換スイッチ制御回路６にその旨の信号を出力して終了する。なお、商用電源監視回路５２や蓄電池監視回路５３の監視期間、異常発生回数、放電深度などの設定値は、後日、外部スイッチなどの設定回路８を用いて再設定することも可能にした。
【発明の効果】
上述したように、本発明に係る無停電電源装置は、商用電源の交流電圧の変動回数または、蓄電池の放電深度を計測し、あらかじめ設定した判定値と比較することによりオフライン方式とオンライン方式の給電を自動的に切り換える方式としたため、従来のオンライン方式より低騒音・省エネとなる。また、商用電源１１の状況に応じてオンライン／オフライン方式を自動的に切り換えることができるため汎用性や信頼性が高いことや、商用電源環境を事前に確認する必要が無いという点においても優れている。
【図面の簡単な説明】
【図１】本発明の無停電電源装置を示すブロック図である。
【図２】本発明例のフローチャートである。
【図３】本発明のフローチャートである。
【図４】本発明の無停電電源装置を示すブロック図である。
【符号の説明】
３：オンライン／オフライン判定回路、４：メモリ、
５：インバータ制御回路、６：電源切換スイッチ制御回路、７：シャント、
８：外部設定回路、１１：商用電源、１２：整流器、１３：鉛蓄電池、
１４：インバータ、１５：電源切換スイッチ、１６：負荷、
２１：周波数検出回路、２２：波形検出回路、２３：低電圧Ａ検出回路、
２４：過電圧Ａ検出回路、２５：低電圧Ｂ検出回路、
２６：過電圧Ｂ検出回路、５０：主回路部、５１：制御回路部、
５２：商用電源監視部、５３：鉛蓄電池監視部、５４：電源切換制御部、
７１：電圧検出回路、７２：電流検出回路、７３：充放電検出回路TECHNICAL FIELD OF THE INVENTION
The present invention relates to switching of a power supply method to a load in an uninterruptible power supply.
[Prior art]
The uninterruptible power supply using a commercial power supply, which has been conventionally used, is roughly classified into a method in which power is always supplied by an inverter (online method) and a method in which power is always supplied by commercial power supply (offline method). Which method is to be selected depends on a) the quality of the commercial power supply, b) the allowable voltage fluctuation value of the load to be used, and c) the cost. FIG. 4 shows a general circuit block diagram of the uninterruptible power supply of the online type and the offline type. Both the online system and the offline system have almost the same circuit configuration. That is, the AC voltage of the commercial power supply 11 is converted into a DC voltage by the rectifier 12 and used for input of the inverter 14 or charging of the lead storage battery 13. Power from the rectifier 12 or the lead storage battery 13 is supplied to the inverter 14. Whether the electric power of the commercial power supply 11 is supplied to the load 16 as it is or the output of the inverter 14 is supplied to the load 16 is switched by the power supply switch 15. The online method and the offline method have the following characteristics, respectively.
The online method is a method in which the inverter 14 is always operated and power is supplied to the load 16. Then, when the output from the inverter 14 becomes excessive or when the inverter 14 fails, the power supply switch 15 is used to switch the power supply from the inverter power supply to the commercial power supply. That is, in the online system, since the inverter is always supplied with power, a stable voltage can be supplied to the load 16. Therefore, it is mainly used in places where the fluctuation of the commercial power supply voltage is large, loads where the voltage fluctuation tolerance is small, and the like. However, since the rectifier 12 simultaneously supplies power to the inverter 14 and charges the lead storage battery 13, a large capacity is required and the cost is high. Further, a large-sized cooling fan is required to suppress the heat generated by the inverter 14 and the rectifier 12, resulting in a problem such as an increase in noise. Therefore, when the online method is used, there is also a problem that the ventilation port is clogged due to the use of a large-sized cooling fan and periodic maintenance and inspection are required due to the large accumulation of dust and the like inside.
On the other hand, the offline method is a method in which the voltage of the commercial power supply 11 is always supplied to the load 16. Then, at the time of power failure or abnormal voltage of the commercial power supply 11, the inverter 14 is operated, and the power supply switch 15 is switched to supply power to the load 16. In addition, since the inverter 14 is not operated at all times, there are advantages such as energy saving, no noise caused by the cooling fan, and little clogging of the ventilation port. However, when the off-line uninterruptible power supply is used in an environment where power supply conditions are poor, inverter power supply and commercial power supply are frequently repeated. Therefore, there is a problem that the depth of discharge of the storage battery used is increased, and as a result, the life of the storage battery is short. In addition, in order to confirm the power supply situation of the commercial power supply, a long-term measurement using a voltmeter, an oscilloscope, a data recorder, and the like is required on site, and there is a problem that it is troublesome and costly.
[Problems to be solved by the invention]
An object of the present invention is to provide an uninterruptible power supply capable of automatically switching between an online system and an offline system according to a fluctuation state of a commercial power supply without having to check the environment of the commercial power supply in advance. is there.
[Means for Solving the Problems]
In order to solve the above problems, in the first invention, a rectifier that converts an AC voltage of a commercial power supply into a DC voltage and supplies the DC voltage to an inverter and a storage battery, an inverter that converts a DC voltage to an AC voltage, and a DC voltage that is supplied to the inverter The uninterruptible power supply has a storage battery, a commercial power supply monitoring circuit that monitors the AC voltage of the commercial power supply, and a power supply switch that switches between power supply from the commercial power supply to the load and power supply from the inverter to the load. If the number of occurrences of voltage abnormalities of the commercial power supply during the monitoring period is larger than a predetermined reference value, a signal for switching from the offline mode to the online mode is output to the inverter and the power switch, and the commercial power supply during the preset monitoring period is output. If the number of occurrences of the voltage abnormality of the power supply is smaller than the predetermined reference value, Invar And a power supply changeover switch is characterized by having the power supply switching control unit for outputting a signal for switching to the off-line method from the online system.
In the second invention, the power supply switching control unit in the first invention, the frequency of the commercial power supply, the phase, when the number of occurrences of abnormality of the waveform is greater than a predetermined reference value in a monitoring period set in advance, the inverter and A signal for switching from the off-line system to the on-line system is output to the power switch, and when the frequency of occurrence of abnormality in the frequency, phase, and waveform of the commercial power supply is smaller than a predetermined reference value in a monitoring period set in advance, the inverter and the inverter are connected. The power supply switch includes a power supply switching control unit that outputs a signal for switching from an online method to an offline method.
In a third aspect, the power supply switching control unit according to the first or second aspect is configured such that the external setting circuit sets a reference value of the number of times of occurrence of abnormality with respect to the monitoring period of the commercial power supply and any one of voltage, frequency, phase, and waveform. It is characterized in that it can be set by the user.
In the fourth invention, a rectifier that converts an AC voltage of a commercial power supply to a DC voltage and supplies it to an inverter and a storage battery, an inverter that converts a DC voltage to an AC voltage, a storage battery that supplies a DC voltage to the inverter, and an AC voltage of a commercial power supply An uninterruptible power supply having a power supply switch for switching between a power supply from a commercial power supply to a load and a power supply from an inverter to a load. When the circuit for monitoring the depth of discharge of the storage battery determines that the depth of discharge of the storage battery is higher than the reference value, a signal for switching from the online mode to the offline mode is output to the inverter and the power switch, and the discharge depth of the storage battery is reduced. If it is determined that it is lower than the reference value, the inverter and It is characterized by having a power supply switching control unit for outputting a signal for switching to the online mode.
The fifth invention is characterized in that the power supply switching control unit in the fourth invention can set a reference value of a depth of discharge by an external setting circuit during a monitoring period of the storage battery.
In the sixth invention, a rectifier that converts an AC voltage of a commercial power supply into a DC voltage and supplies it to an inverter and a storage battery, an inverter that converts a DC voltage into an AC voltage, a storage battery that supplies a DC voltage to the inverter, and an AC voltage of a commercial power supply Power supply monitoring circuit, a circuit for monitoring the depth of discharge of the storage battery, an uninterruptible power supply having a power supply switch for switching between power supply from the commercial power supply to the load and power supply from the inverter to the load. When the number of occurrences of the abnormal voltage of the commercial power supply during the set monitoring period is larger than the predetermined reference value, and the circuit that monitors the depth of discharge of the storage battery determines that the depth of discharge of the storage battery is higher than the reference value, A signal to switch from the offline mode to the online mode is output to the inverter and the power switch. If the number of occurrences of abnormal voltage of the commercial power supply in the boss was monitored period is smaller than a predetermined reference value, and the depth of discharge of the storage battery by a circuit for monitoring the discharge depth of storage battery is determined to be higher than a standard value, It is characterized in that the inverter and the power supply switch have a power supply switching control unit that outputs a signal for switching from the online method to the offline method.
In the seventh invention, the power supply switching control unit in the sixth invention comprises: a monitoring period of the commercial power supply, a reference value of the number of times of occurrence of abnormality in any of voltage, frequency, phase, and waveform; a monitoring period of the storage battery; Is settable by an external setting circuit.
【Example】
Hereinafter, an embodiment of the present invention will be described. FIG. 1 is a block diagram of the apparatus of the present invention, and FIGS.
In FIG. 1, the present invention is roughly composed of a main circuit unit 50 and a control circuit unit 51. The main circuit unit 50 is configured by a circuit that performs the following operation. That is, the AC of the commercial power supply 11 is converted into DC by the rectifier 12, and the lead storage battery 13 is charged through the shunt 7 and power is supplied to the inverter 14. The power supply switch 15 outputs the power supplied to the load 16 by bypassing the commercial power supply 11 or the inverter 14 according to a signal from the power supply switch control circuit 6 of the control circuit unit 51 described later. It is a device to switch between.
On the other hand, the control circuit section 51 is roughly composed of a commercial power supply monitoring section 52, a lead storage battery monitoring section 53, and a power supply switching control section 54. The commercial power supply monitoring unit 52 is a circuit unit that detects the voltage, frequency, waveform, and phase of the commercial power supply 11 and outputs the content to the power supply switching control unit 54. The frequency detection circuit 21 detects whether or not the frequency of the commercial power supply 11 is abnormal. The waveform and the phase of the commercial power supply 11 are detected by the waveform detection circuit 22. The voltage of the commercial power supply 11 is detected by a low voltage A detection circuit 23, an overvoltage A detection circuit 24, a low voltage B detection circuit 25, and an overvoltage B detection circuit 26.
The lead storage battery monitoring unit 53 includes a voltage detection circuit 71 for detecting a voltage of the lead storage battery 13, a shunt 7 and a current detection circuit 72 for detecting a charge / discharge current, and a discharge depth of the lead storage battery based on data measured by these circuits. From the charge / discharge detection circuit 73 that calculates
The power supply switching control unit 54 controls the switching between the offline method and the online method based on the fluctuation of the commercial power output from the commercial power monitoring unit 52 and the depth of discharge of the lead storage battery 13 output from the lead storage battery monitoring unit 53. Part. The external setting circuit 8 can manually reset the abnormality of the commercial power supply voltage described later, the monitoring period of the lead-acid battery discharge depth, and the contents of the determination.
FIG. 2 is a flowchart of the commercial power supply monitoring unit 52 of the present apparatus. In S11, the commercial power supply voltage is taken.
The steps after S21 measure the frequency and the phase difference of the AC voltage of the commercial power supply. In S22, if the measured frequency of the commercial power supply is within the range of 48 to 52 Hz (in this embodiment, the frequency is 50 Hz), the frequency is determined to be normal and the process proceeds to S23. It goes to S25 and stores it so as to instruct the online method. In S23, if the phase difference of the AC voltage of the commercial power supply is within 5 °, it is stored as normal and the offline method is instructed in S24. If the phase difference exceeds 5 °, the process goes to S25 as abnormal and goes to S25 to change the online method. Memorize as instructed.
The steps after S31 are a part for measuring, determining and storing the effective value of the AC voltage of the commercial power supply. In S32, if the effective value of the AC voltage is less than 90V, the procedure goes to S33, and if it is 90V or more, the procedure goes to S34. In S33, if the effective value of the AC voltage is in the range of 80 to 90 V, the flow goes to S51, where it is determined that the low voltage A is set, and the data is stored. On the other hand, if the effective value of the AC voltage is out of the range of 80 to 90 V, the process goes to S52 and determines that the voltage is 80 V or less. In S34, if the effective value of the AC voltage exceeds 110V, the process goes to S35, and if it is 110V or less (i.e., 90 to 110V), the process goes to S36 to determine that the voltage is normal. In S35, if the effective value of the AC voltage is in the range of 110 to 120V, the flow goes to S53, where it is determined that the overvoltage is A, and the data is stored. On the other hand, if the effective value of the AC voltage is out of the range of 110 to 120 V (120 V or more), the process goes to S54 to determine the overvoltage B and store the data. That is, when the range of the effective value of the AC voltage is 90 V or less or 110 V or more, the values stored in S51 to S54 are different depending on the voltage condition, but are stored in S56 so as to instruct the online method as a whole.
The steps after S41 are a part for measuring the waveform of the commercial power supply. In S42, if the peak value of the AC voltage is less than 110V, the flow goes to S55 to determine an instantaneous power failure, and if it is 110V or more, the flow goes to S43. In S43, if the instantaneous interruption time of the voltage waveform of the commercial power supply is 2 ms (0.002 seconds) or more, go to S55 and determine an instantaneous power failure, and if less than 2 ms, go to S44 and determine that the voltage waveform is normal. I do. Therefore, when the voltage waveform is normal, the memory is stored so as to instruct the offline method in S46, and when the voltage waveform is abnormal, the memory is stored so as to instruct the online method in S56.
Next, the operation of the online / offline determination circuit 3 for switching the operation of the uninterruptible power supply in the offline mode or the online mode will be described with reference to the flowchart shown in FIG. This part is a part for determining whether to use the off-line method or the on-line method according to the fluctuation of the commercial power supply 11 and the state of the depth of discharge of the lead storage battery 13.
After confirming the initial operation in S61, when starting the uninterruptible power supply, the offline method is set. In S62, a monitoring period of the commercial power supply 11 is set. A determination period for switching from the offline mode to the online mode is TF1, and a determination period for switching from the online mode to the offline mode, which is the return condition, is TF2. In this embodiment, TF1 is set to one month and TF2 is set to one day. As described above, in order to operate in the off-line mode as much as possible, the off-line mode is instructed when the voltage of the commercial power supply 11 is stabilized for about one day.
S63 is a step of setting a reference value for switching between the online / offline method from the monitoring result of the commercial power supply 11. Regarding the number of occurrences of an abnormality in the commercial power supply 11, a reference value for switching from the offline method to the online method is GF1, and a reference value for the return condition for switching from the online method to the offline method is GF2. In this embodiment, GF1 is set to 10 times, and GF2 is set to 1 time. Then, from S62 and S63, if an abnormality (GF1) occurs 10 times in one month (TF1) and one or more (GF2) occurs in one day (TF2), the system changes from the offline method to online. I decided to instruct to switch to the system. That is, only when the abnormality of the commercial power supply 11 frequently occurs in a short period, the system is switched from the offline system to the online system.
In S64, a monitoring period of the depth of discharge of the lead storage battery is set. First, a monitoring period for switching from the offline system to the online system is TB1, and a monitoring period for switching from the online system to the offline system, which is a return condition, is TB2. In this embodiment, TB1 is set to one month, and TB2 is set to one day.
In S65, the on-line / off-line system of the uninterruptible power supply and a reference value for switching are set. The reference value of the lead-acid battery discharge depth for switching the line fashion from the offline method and GB1, the return condition for switching from the on-line system to the offline method and GB2. In this embodiment, GB1 is 20% and GB2 is 5%. That is, in the off-line system, it is assumed that the voltage of the commercial power supply 11 is stable, and the problem is small even if the depth of discharge of the lead storage battery is relatively high. Note that a discharge depth of 50% is a state in which half of the capacity of the lead storage battery at the time of full charge has been discharged.
In S66, the data stored (described in the flowchart of FIG. 2) by the commercial power supply monitoring circuit 52 is read. On the other hand, in S67, the data of the depth of discharge of the lead storage battery stored in the lead storage battery monitoring unit 53 is read. In S68, it is confirmed whether the system is currently operating in the offline mode or the online mode. If the system is operating in the offline mode, the procedure goes to S71. If the apparatus is operating in the online mode, the procedure goes to S81. In S71, it is determined whether the voltage fluctuation of the commercial power supply 11 and the depth of discharge of the lead storage battery are within the range of the set reference value, that is, whether it is necessary to switch from the offline method to the online method. On the other hand, in S81, it is determined whether the voltage fluctuation of the commercial power supply 11 and the depth of discharge of the lead storage battery are within the range of the set reference value, that is, whether it is necessary to switch from the online method to the offline method. From these determination results, the offline method is selected in S72 and the online method is selected in S82. When switching the output method of the uninterruptible power supply, a signal to that effect is output to the inverter control circuit 5 and the power supply changeover switch control circuit 6, and the process is terminated. The setting values of the monitoring period, the number of occurrences of the abnormality, the depth of discharge, and the like of the commercial power supply monitoring circuit 52 and the storage battery monitoring circuit 53 can be reset at a later date using the setting circuit 8 such as an external switch.
【The invention's effect】
As described above, the uninterruptible power supply according to the present invention measures the number of fluctuations of the AC voltage of the commercial power supply or the depth of discharge of the storage battery, and compares it with a predetermined determination value to supply power in the offline method and the online method. Is automatically switched, so that the noise and energy consumption are lower than the conventional online method. In addition, since the on-line / off-line method can be automatically switched according to the status of the commercial power supply 11, the versatility and reliability are high, and there is no need to check the commercial power supply environment in advance. I have.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an uninterruptible power supply according to the present invention.
FIG. 2 is a flowchart of an example of the present invention.
FIG. 3 is a flowchart of the present invention.
FIG. 4 is a block diagram showing an uninterruptible power supply of the present invention.
[Explanation of symbols]
3: Online / offline determination circuit 4: Memory,
5: Inverter control circuit, 6: Power supply changeover switch control circuit, 7: Shunt,
8: external setting circuit, 11: commercial power supply, 12: rectifier, 13: lead storage battery,
14: Inverter, 15: Power switch, 16: Load,
21: frequency detection circuit, 22: waveform detection circuit, 23: low voltage A detection circuit,
24: Overvoltage A detection circuit 25: Low voltage B detection circuit
26: overvoltage B detection circuit, 50: main circuit section, 51: control circuit section,
52: commercial power supply monitoring unit, 53: lead storage battery monitoring unit, 54: power supply switching control unit,
71: voltage detection circuit, 72: current detection circuit, 73: charge / discharge detection circuit

Claims

Rectifier that converts AC voltage of commercial power supply to DC voltage and supplies it to inverter and storage battery, inverter that converts DC voltage to AC voltage, storage battery that supplies DC voltage to inverter, and commercial power supply monitoring that monitors AC voltage of commercial power supply In an uninterruptible power supply having a power supply changeover switch for switching between a circuit, power supply from a commercial power supply to a load, and power supply from an inverter to a load, the number of occurrences of a voltage abnormality of the commercial power supply during a preset monitoring period is predetermined. Is greater than the reference value, the inverter and the power supply switch are switched from a continuous commercial power supply system (hereinafter, referred to as an offline system) for supplying commercial power to a load, to a continuous inverter power supply system (hereinafter, referred to as an off-line system) for supplying the output of the inverter. , Which is called an online method), and outputs a signal to switch to the monitoring period set in advance. If the number of occurrences of abnormal voltage of definitive commercial power is smaller than a predetermined reference value, the inverter and the power changeover switch, characterized by having a power supply switching control unit for outputting a signal for switching to the off-line method from the online system Uninterruptible power system.

When the frequency of occurrence of the frequency, phase, and waveform abnormalities of the commercial power supply is larger than a predetermined reference value in a preset monitoring period, the power supply switching control unit switches the inverter and the power supply changeover switch from the offline method to the online method. If the frequency of occurrence of abnormalities in the frequency, phase, and waveform of the commercial power supply is smaller than a predetermined reference value during a preset monitoring period, the inverter and power supply switch are switched from online to offline. 2. The uninterruptible power supply according to claim 1, wherein the uninterruptible power supply outputs a signal for switching the power supply to the uninterruptible power supply.

2. The power supply switching control unit according to claim 1, wherein a reference value of the number of times of occurrence of an abnormality can be set by an external setting circuit for a monitoring period of the commercial power supply and any one of voltage, frequency, phase, and waveform. Or the uninterruptible power supply according to claim 2.

Rectifier that converts AC voltage of commercial power to DC voltage and supplies it to inverter and storage battery; inverter that converts DC voltage to AC voltage; storage battery that supplies DC voltage to inverter; commercial power supply monitoring that monitors AC voltage of commercial power In an uninterruptible power supply having a circuit, a circuit for monitoring the depth of discharge of a storage battery, and a power supply switch for switching between a power supply from a commercial power supply to a load and a power supply from an inverter to a load, the depth of discharge of the storage battery is monitored. When it is determined that the depth of discharge of the storage battery is higher than the reference value by the circuit to perform, a signal for switching from the online mode to the offline mode is output to the inverter and the power supply switch, and if the discharge depth of the storage battery is lower than the reference value. If judged, the inverter and power switch are switched from offline to online Uninterruptible power supply, characterized in that it comprises a power supply switching control unit for outputting a signal for switching.

5. The uninterruptible power supply according to claim 4, wherein the power supply switching control unit can set a reference value of a discharge depth during a monitoring period of the storage battery by an external setting circuit.

Rectifier that converts AC voltage of commercial power supply to DC voltage and supplies it to inverter and storage battery, inverter that converts DC voltage to AC voltage, storage battery that supplies DC voltage to inverter, and commercial power supply monitoring that monitors AC voltage of commercial power supply In an uninterruptible power supply having a circuit, a circuit for monitoring the depth of discharge of a storage battery, and a power supply switch for switching between power supply from a commercial power supply to a load and power supply from an inverter to a load, a commercial power supply for a preset monitoring period If the number of occurrences of power supply voltage abnormalities is greater than a predetermined reference value and the circuit that monitors the depth of discharge of the storage battery determines that the depth of discharge of the storage battery is higher than the reference value, the inverter and the power supply switch are switched. , Output a signal to switch from offline mode to online mode, and set the monitoring period If the number of occurrences of abnormal voltage of definitive commercial power is smaller than a predetermined reference value, and the depth of discharge of the storage battery by a circuit for monitoring the discharge depth of storage battery it is determined to be higher than the reference value, the inverter and the power supply changing An uninterruptible power supply device, characterized in that the switch has a power supply switching control unit that outputs a signal for switching from an online method to an offline method.

The power supply switching control unit sets a reference value of the number of occurrences of abnormality for any of the monitoring period of the commercial power supply, the voltage, the frequency, the phase, and the waveform, and a monitoring period of the storage battery and a reference value of the depth of discharge by an external setting circuit. 7. The uninterruptible power supply according to claim 6, wherein the power supply can be used.