JPH0744873U

JPH0744873U - Uninterruptible power system

Info

Publication number: JPH0744873U
Application number: JP001278U
Authority: JP
Inventors: 毅岩田
Original assignee: 株式会社三陽電機製作所
Priority date: 1995-03-02
Filing date: 1995-03-02
Publication date: 1995-11-28
Anticipated expiration: 2003-03-18
Also published as: JP2576237Y2

Abstract

(57)【要約】【目的】無負荷時の停電でインバータが動作しないよ
うにする。【構成】商用電源からの入力電流線２４と、負荷への
出力電流線２３とに共通に電流検出トランス２５が設け
られる。停電時に蓄電池１６の出力インバータ１３出交
流に変換して負荷へ出力するが、上記電流検出トランス
２５から電流が検出されないことを判定回路２６で検出
するとインバータ１３の動作を停止させる。 (57) [Summary] [Purpose] To prevent the inverter from operating due to a power failure with no load. [Configuration] A current detection transformer 25 is provided commonly to an input current line 24 from a commercial power source and an output current line 23 to a load. When a power failure occurs, the output of the storage battery 16 is converted into an AC output from the inverter 13 and is output to the load. However, when the determination circuit 26 detects that no current is detected by the current detection transformer 25, the operation of the inverter 13 is stopped.

Description

[Detailed description of the device]

【０００１】[0001]

[Industrial applications]

この考案は、商用電源が停電しても、常に安定した電力を負荷へ供給できる、コンピュータ機器を始め多くの電気装置の電源装置として使用される無停電電源装置に関するものである。 The present invention relates to an uninterruptible power supply used as a power supply for many electric devices such as computer equipment, which can always supply stable power to a load even when a commercial power supply fails.

【０００２】[0002]

[Prior art]

従来の無停電電源装置（ＵＰＳと記す）を図５のブロック系統図を参照して説明する。端子１１からの商用電源電力は整流器１２で整流され、その整流出力はインバータ１３で交流電力に変換されて出力端子１４へ出力される。端子１１からの電力により充電器１５を通じて蓄電池１６に対する充電が行われている。停電中は蓄電池１６の電力が逆流阻止ダイオード１７を通じてインバータ１３へ供給され、インバータ１３で交流電力に変換されて出力される。 A conventional uninterruptible power supply (referred to as UPS) will be described with reference to the block system diagram of FIG. The commercial power supply power from the terminal 11 is rectified by the rectifier 12, and the rectified output is converted into AC power by the inverter 13 and output to the output terminal 14. The storage battery 16 is charged through the charger 15 by the power from the terminal 11. During a power failure, the power of the storage battery 16 is supplied to the inverter 13 through the reverse current blocking diode 17, converted into AC power by the inverter 13, and output.

【０００３】端子１１からの商用電力は信号絶縁トランス１８を介して停電検出回路１９へ供給され、停電検出回路１９は停電を検出するとＨレベルを出力してＮＡＮＤ回路２１へ供給する。一方出力端子１４の負荷電流が電流検出器２２で検出され、電流検出器２２は検出電流が０で無負荷の場合はＨレベルを出力してＮＡＮＤ回路２１へ供給する。停電中でありかつ無負荷であるとＮＡＮＤ回路２１の出力からインバータ停止信号が出力され、インバータ１３の動作が停止される。このようにして停電中の無負荷状態では蓄電池１６の放電が防止される。Commercial power from the terminal 11 is supplied to the power failure detection circuit 19 via the signal isolation transformer 18, and when the power failure detection circuit 19 detects a power failure, it outputs H level and supplies it to the NAND circuit 21. On the other hand, the load current of the output terminal 14 is detected by the current detector 22, and the current detector 22 outputs the H level and supplies it to the NAND circuit 21 when the detected current is 0 and there is no load. When there is a power failure and there is no load, an inverter stop signal is output from the output of the NAND circuit 21 and the operation of the inverter 13 is stopped. In this way, discharge of the storage battery 16 is prevented in a no-load state during a power failure.

【０００４】[0004]

[Problems to be solved by the device]

ＵＰＳは、商用電源を整流した直流電力かまたは、蓄電池１６の直流電力でインバータ１３が常時動作しており、停電検出回路１９及び信号絶縁用トランス１８は、停電時無負荷でインバータ１３が動作するのを防止するためだけに使われていた。ＵＰＳの低コスト化の要求が強まる中で、回路の簡素化、部品点数の削減が求められている。 In the UPS, the inverter 13 is constantly operating with the DC power obtained by rectifying the commercial power or the DC power of the storage battery 16, and the power failure detection circuit 19 and the signal isolation transformer 18 have the inverter 13 with no load at the time of power failure. It was only used to prevent it from working. Amid the increasing demand for cost reduction of UPS, simplification of circuits and reduction of the number of parts are required.

【０００５】[0005]

[Means for Solving the Problems]

この考案によれば無停電電源装置の出力電流線と商用電源の入力電流線とに共通に電流検出トランスが設けられ、その電流検出トランスに電流が流れていない場合、つまり停電中でありかつ無負荷状態である場合を電流検出判定回路で検出し、その検出出力によりインバータの動作を停止させる。 According to this invention, the output current line of the uninterruptible power supply and the input current line of the commercial power supply are provided with the current detection transformer in common, and when the current does not flow in the current detection transformer, that is, during the power failure and The case of no load is detected by the current detection judgment circuit, and the output of that detection stops the operation of the inverter.

【０００６】[0006]

【Example】

この考案の実施例を図１に示す。図１において図５と対応する部分には同一符号を付けてある。この考案においては無停電電源装置の出力電流線２３と、商用電源の入力電流線２４とに共通に電流検出トランス２５が設けられる。電流検出トランス２５の出力は電流検出判定回路２６に供給され、電流検出トランス２５に電流が流れていない場合、つまり停電中であり、かつ無負荷状態である場合に電流検出判定回路２６からインバータ停止信号が出力される。 An embodiment of this invention is shown in FIG. In FIG. 1, parts corresponding to those in FIG. 5 are designated by the same reference numerals. In this invention, a current detection transformer 25 is commonly provided for the output current line 23 of the uninterruptible power supply and the input current line 24 of the commercial power supply. The output of the current detection transformer 25 is supplied to the current detection determination circuit 26, and when no current flows in the current detection transformer 25, that is, when there is a power failure and there is no load, the current detection determination circuit 26 stops the inverter. The signal is output.

【０００７】電流検出判定回路２６は例えば図２に示すように構成される。電流検出トランス２５は比較器２７に接続され、比較器２７の非反転入力端は接地され、出力端は抵抗器２８を通じて正の電源端子２９に接続されると共にコンデンサ３１を通じて負の電源端子３２に接続され、更にツェナーダイオード３３を通じてトランジスタ３４のベースに接続され、トランジスタ３４のコレクタは電源端子２９に接続され、エミッタは電源端子３２に接続される。The current detection determination circuit 26 is configured, for example, as shown in FIG. The current detection transformer 25 is connected to the comparator 27, the non-inverting input terminal of the comparator 27 is grounded, the output terminal is connected to the positive power supply terminal 29 through the resistor 28, and the negative terminal is connected through the capacitor 31. It is connected to the power supply terminal 32 and further connected to the base of the transistor 34 through the Zener diode 33. The collector of the transistor 34 is connected to the power supply terminal 29 and the emitter is connected to the power supply terminal 32.

【０００８】電流検出トランス２５は貫通する線２３，２４のいずれかに電流が流れている場合、電流検出トランス２５の出力に電圧が発生する。この電圧が比較器２７に入力され、比較器２７の−端子に＋端子より高い電圧が印加されたとき比較器２７の出力はＬレベルになり、コンデンサ３１に蓄積された電荷を放電させる（１サイクルに１回）。コンデンサ３１を充電する抵抗器２８の定数は、コンデンサ３１，抵抗器２８の時定数ＣＲが被検出電流の１サイクル時間より長い数値に選定されるため、整流器負荷の電流波形（例えば図３に示すＵＰＳ入力電流波形）のように無電流期間があっても、コンデンサ３１の電圧はツェナーダイオード３３のツェナー電圧には達しない（図３）。In the current detection transformer 25, when a current flows through any of the wires 23 and 24 passing through the current detection transformer 25, a voltage is generated at the output of the current detection transformer 25. When this voltage is input to the comparator 27 and a voltage higher than the + terminal is applied to the − terminal of the comparator 27, the output of the comparator 27 becomes L level, and the electric charge accumulated in the capacitor 31 is discharged ( Once a cycle). The constant of the resistor 28 that charges the capacitor 31 is selected such that the time constant CR of the capacitor 31 and the resistor 28 is longer than one cycle time of the detected current, so that the current waveform of the rectifier load (for example, in FIG. The voltage of the capacitor 31 does not reach the Zener voltage of the Zener diode 33 even if there is no current period (see UPS input current waveform) (FIG. 3).

【０００９】ＵＰＳの出力が無負荷となり出力電流が流れなくなっても、ＵＰＳ内部のインバータは無負荷運転を行っているため、ＵＰＳ入力電流は若干の電流が流れ続けている。停電が発生するとＵＰＳ入力電流もなくなるため、比較器２７の出力はＨレベルとなり、抵抗器２８を通してコンデンサ３１が充電され、徐々に電圧が上昇する。コンデンサ３１の電圧が（ツェナーダイオード３３のツェナー電圧）＋（トランジスタ３４のベース・エミッタ間電圧）を超えるとトランジスタ３４がＯＮとなり、インバータ停止信号を発生させる（図３）。Even if the output of the UPS becomes unloaded and the output current does not flow, the inverter inside the UPS is operating under no load, so that a small amount of UPS input current continues to flow. When a power failure occurs, the UPS input current also disappears, so the output of the comparator 27 becomes H level, the capacitor 31 is charged through the resistor 28, and the voltage gradually rises. When the voltage of the capacitor 31 exceeds (the Zener voltage of the Zener diode 33) + (the voltage between the base and emitter of the transistor 34), the transistor 34 is turned on and an inverter stop signal is generated (FIG. 3).

【００１０】なお、比較器２７の入力端子がともに無電圧で比較器２７の出力レベルがＨレベルに安定しない比較器の場合には、図４に示すように比較器２７の入力にバイアス電圧−Ｖ_C×Ｒ₁／（Ｒ₁＋Ｒ₂）を印加することもある。図４の場合では、電流検出トランス２５の出力電圧がバイアス電圧（例えばＶ_C＝５Ｖ，Ｒ₁＝１００Ω，Ｒ₂＝５ｋΩの場合−0.１Ｖ）より高くなったとき、受電中あるいは負荷電流が流れていると判定される。電流検出トランス２５の出力電圧はバイアス電圧に比べ、はるかに大きい信号であるため、検出電流の差はわずかである。In the case of a comparator in which both input terminals of the comparator 27 have no voltage and the output level of the comparator 27 does not stabilize at the H level, a bias is applied to the input of the comparator 27 as shown in FIG. A voltage -V _C × R ₁ / (R ₁ + R ₂ ) may be applied. In the case of FIG. 4, when the output voltage of the current detection transformer 25 becomes higher than the bias voltage (for example, -0.1 V when V _C = 5V, R ₁ = 100Ω, R ₂ = 5 kΩ), the power is being received or the load current is being received. Is determined to be flowing. Since the output voltage of the current detection transformer 25 is a much larger signal than the bias voltage, the difference between the detected currents is small.

【００１１】比較器２７の入力端子間のダイオード３５，３６は、過大な検出電圧信号をバイパスさせ、比較器２７を保護するためのものである。The diodes 35 and 36 between the input terminals of the comparator 27 are for protecting the comparator 27 by bypassing an excessive detection voltage signal.

【００１２】[0012]

[Effect of device]

この考案によれば、従来、休日等で負荷装置を利用していないときに停電が発生した場合に起きる蓄電池放電が、簡単で低コストの回路で防止できる。この結果、特定のＵＰＳに限られていた無負荷運転防止回路が通常のＵＰＳにも取り付け可能となり蓄電池の放電サイクル数が減少し、蓄電池の長寿命化が期待できる。 According to the present invention, it is possible to prevent the discharge of the storage battery, which would otherwise occur when a power failure occurs while the load device is not used on holidays or the like, with a simple and low-cost circuit. As a result, the no-load operation prevention circuit, which was limited to a specific UPS, can be installed in a normal UPS, the number of discharge cycles of the storage battery is reduced, and the life of the storage battery can be expected to be extended.

[Brief description of drawings]

【図１】この考案による無停電電源装置の一例を示すブ
ロック図。FIG. 1 is a block diagram showing an example of an uninterruptible power supply device according to the present invention.

【図２】図１中の電流検出判定回路２６の具体例を示す
接続図。FIG. 2 is a connection diagram showing a specific example of a current detection determination circuit 26 in FIG.

【図３】図１，図２の各部の電圧・電流を示すチャー
ト。FIG. 3 is a chart showing the voltage / current of each part of FIGS. 1 and 2.

【図４】電流検出判定回路２６の他の例を示す接続図。FIG. 4 is a connection diagram showing another example of a current detection determination circuit 26.

【図５】従来の無停電電源装置を示すブロック図。FIG. 5 is a block diagram showing a conventional uninterruptible power supply device.

Claims

[Scope of utility model registration request]

1. The AC power is supplied to the load based on the commercial power when the commercial power is being received, and the DC power of the storage battery is converted to AC power by the inverter while the commercial power is out of power. In the uninterruptible power supply that supplies to the load, if a current detection transformer is provided in common for the output current line of the uninterruptible power supply and the input current line of the commercial power supply, and no current flows in the current detection transformer An uninterruptible power supply device comprising: a current detection determination circuit for stopping the inverter.