JPH0833338A - Discharge circuit for smoothing capacitor - Google Patents

Discharge circuit for smoothing capacitor

Info

Publication number
JPH0833338A
JPH0833338A JP6163980A JP16398094A JPH0833338A JP H0833338 A JPH0833338 A JP H0833338A JP 6163980 A JP6163980 A JP 6163980A JP 16398094 A JP16398094 A JP 16398094A JP H0833338 A JPH0833338 A JP H0833338A
Authority
JP
Japan
Prior art keywords
circuit
smoothing capacitor
contact
power supply
resistor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP6163980A
Other languages
Japanese (ja)
Inventor
Hiroshi Sawada
浩 沢田
Kazuhiro Matsuoka
和宏 松岡
Chukichi Mukai
忠吉 向井
Tomoaki Izumimoto
智昭 泉本
Hiroshi Mizuno
博史 水野
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Electric Works Co Ltd
Original Assignee
Matsushita Electric Works Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Works Ltd filed Critical Matsushita Electric Works Ltd
Priority to JP6163980A priority Critical patent/JPH0833338A/en
Publication of JPH0833338A publication Critical patent/JPH0833338A/en
Withdrawn legal-status Critical Current

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  • Inverter Devices (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Direct Current Feeding And Distribution (AREA)
  • Rectifiers (AREA)

Abstract

PURPOSE:To prevent power loss due to a discharge resistor during power supply to a rectifier circuit while reducing the power capacity of the discharge resistor. CONSTITUTION:A parallel circuit of a current limit resistor R1 for protecting a main circuit INV against surge current and a contact rL of relay RyL is inserted between a rectifier circuit RE and a smoothing capacitor C. The smoothing capacitor C is connected in parallel with a series circuit of a discharge resistor RD and a contact rD of a relay RyD. Immediately after starting power supply to the rectifier circuit RE, a control circuit CN turns both contacts rL, rD OFF to pass a rush current through the current limit resistor rL thus protecting the main circuit INV against the rush current. Upon elapse of a predetermined time after starting power supply to the rectifier circuit RE, the contact rL, is turned on to feed power to the main INV not through the current limit resistor rL. Upon interruption of power supply to the rectifier circuit RE, the contact rD is turned on to discharge the smoothing capacitor C through the discharge resistor RD.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、主としてインバータ装
置に用いられ、商用電源を整流回路で整流した後に平滑
するために用いる平滑コンデンサについて、整流回路へ
の給電停止後に平滑コンデンサの電荷を短時間で放電さ
せる平滑コンデンサの放電回路に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a smoothing capacitor mainly used in an inverter device and used for smoothing after rectifying a commercial power source by a rectifying circuit, and after the power supply to the rectifying circuit is stopped, the charge of the smoothing capacitor is short The present invention relates to a discharging circuit of a smoothing capacitor that is discharged by.

【０００２】[0002]

【従来の技術】一般に、インバータ装置では商用電源を
整流回路で整流し、平滑コンデンサで平滑した後に、主
回路で交番電力に変換し、この交番電力を電動機のよう
な負荷に供給する構成を有している。すなわち、インバ
ータ装置は図５に示すように、整流回路ＲＥおよび平滑
コンデンサＣで商用電源のような交流電源から直流を得
て、この直流を交番電力に変換する主回路ＩＮＶを負荷
回路とする構成を有している。この種のインバータ装置
では、保守点検時に給電を停止したときに、平滑コンデ
ンサＣの両端電圧が給電停止から１分以内に直流５０Ｖ
以下になることが要求される。2. Description of the Related Art Generally, an inverter device has a structure in which a commercial power source is rectified by a rectifier circuit, smoothed by a smoothing capacitor, converted into alternating power in a main circuit, and the alternating power is supplied to a load such as an electric motor. are doing. That is, as shown in FIG. 5, the inverter device has a configuration in which a rectifier circuit RE and a smoothing capacitor C are used to obtain a direct current from an alternating current power source such as a commercial power source, and a main circuit INV that converts this direct current into alternating power is used as a load circuit. have. In this type of inverter device, when the power supply is stopped during maintenance and inspection, the voltage across the smoothing capacitor C is 50 V DC within 1 minute after the power supply is stopped.
The following is required.

【０００３】このような要求を満たすために、従来は平
滑コンデンサＣに対して放電用抵抗ＲD を並列接続して
いた。この構成では、商用電源から整流回路ＲＥへの給
電が停止すると、平滑コンデンサＣの電荷は放電用抵抗
ＲD を通して放電されるから、平滑コンデンサＣの容量
に応じて上記条件が満たされるように放電用抵抗ＲDの
値が設定される。また、図５において整流回路ＲＥと平
滑コンデンサＣとの間には、電源投入時に主回路ＩＮＶ
に突入電流が流れるのを防止するための限流用抵抗ＲL
が挿入されるとともに、整流回路ＲＥへの給電開始から
所定時間が経過すると限流用抵抗ＲL の両端間を短絡す
るためのスイッチ要素ＳL が挿入されている。In order to meet such requirements, conventionally, a discharging resistor R D is connected in parallel to a smoothing capacitor C. In this configuration, when the power supply from the commercial power source to the rectifier circuit RE is stopped, the electric charge of the smoothing capacitor C is discharged through the discharging resistor R D , so that the above condition is satisfied according to the capacity of the smoothing capacitor C. The value of the resistance RD for use is set. Further, in FIG. 5, the main circuit INV is provided between the rectifier circuit RE and the smoothing capacitor C when the power is turned on.
Current limiting resistor R L to prevent inrush current from flowing into the
And a switch element S L for short-circuiting both ends of the current limiting resistor R L after a lapse of a predetermined time from the start of power supply to the rectifier circuit RE.

【０００４】[0004]

【発明が解決しようとする課題】ところで、上記構成で
は、商用電源からの給電が行なわれている期間には、放
電用抵抗ＲD の両端間に常時電圧が印加され、しかも放
電用抵抗ＲD は比較的抵抗値が小さく設定されるもので
あるから、放電用抵抗ＲD の発熱量が多く、無駄な電力
損失が生じるとともに、放電用抵抗ＲD として電力容量
の大きなものが必要になって製造コストの上昇につなが
るという問題がある。[SUMMARY OF THE INVENTION Incidentally, in the above configuration, the period during which the power supply is being performed from the commercial power source, normally a voltage is applied across the discharge resistor R D, moreover discharge resistor R D Since the resistance value is set to be relatively small, the discharge resistor R D generates a large amount of heat, resulting in unnecessary power loss, and a discharge resistor R D having a large power capacity is required. There is a problem that it leads to an increase in manufacturing cost.

【０００５】本発明は上記問題点の解決を目的とするも
のであり、整流回路への給電中における無駄な電力損失
をなくすとともに、放電用抵抗の電力容量を低減し製造
コストを低減することができるようにした平滑コンデン
サの放電回路を提供しようとするものである。An object of the present invention is to solve the above-mentioned problems, and it is possible to eliminate wasteful power loss during power supply to a rectifier circuit, reduce the power capacity of a discharge resistor, and reduce manufacturing costs. It is intended to provide a discharge circuit for a smoothing capacitor that is made possible.

【０００６】[0006]

【課題を解決するための手段】請求項１の発明は、整流
回路と平滑コンデンサとの間に負荷回路への突入電流を
防止する限流用抵抗と第１のスイッチ要素との並列回路
を挿入し、平滑コンデンサに放電用抵抗と第２のスイッ
チ要素との直列回路を並列接続し、整流回路への給電開
始直後には第１のスイッチ要素をオフにし、給電開始か
ら所定時間の経過後に第１のスイッチ要素をオンにし、
給電が停止すると第２のスイッチ要素をオンにするよう
に第１のスイッチ要素と第２のスイッチ要素とを制御す
る制御回路を設けたことを特徴とする。According to a first aspect of the present invention, a parallel circuit including a current limiting resistor for preventing an inrush current to a load circuit and a first switch element is inserted between a rectifying circuit and a smoothing capacitor. , A series circuit of a discharging resistor and a second switch element is connected in parallel to the smoothing capacitor, the first switch element is turned off immediately after the start of power supply to the rectifier circuit, and the first switch is operated after a predetermined time has elapsed from the start of power supply. Turn on the switch element of
A control circuit for controlling the first switch element and the second switch element is provided so as to turn on the second switch element when power supply is stopped.

【０００７】請求項２の発明は、整流回路と平滑コンデ
ンサとの間に負荷回路への突入電流を防止する限流用抵
抗とリレーの常開接点との並列回路を挿入し、平滑コン
デンサに放電用抵抗とリレーの常閉接点との直列回路を
並列接続し、整流回路への給電開始から所定時間の経過
後に常開接点をオンにするとともに給電が停止するまで
常開接点をオンに保ち、給電停止後に常閉接点をオンに
するようにリレーを制御する制御回路を設けたことを特
徴とする。According to a second aspect of the present invention, a parallel circuit of a current limiting resistor for preventing an inrush current to the load circuit and a normally open contact of the relay is inserted between the rectifier circuit and the smoothing capacitor to discharge the smoothing capacitor. Connect a series circuit of a resistor and a normally closed contact of the relay in parallel, turn on the normally open contact after a lapse of a predetermined time from the start of power supply to the rectifier circuit, and keep the normally open contact on until the power supply stops It is characterized in that a control circuit for controlling the relay is provided so as to turn on the normally closed contact after the stop.

【０００８】請求項３の発明は、整流回路と平滑コンデ
ンサとの間に負荷回路への突入電流を防止する限流用抵
抗を挿入し、限流用抵抗と平滑コンデンサの一端との接
続点に共通接点を接続した双投型接点を有するリレーの
常開側接点を限流用抵抗と整流回路との接続点に接続
し、整流回路と平滑コンデンサの他端との接続点に一端
を接続した放電用抵抗の他端にリレーの常閉側接点を接
続し、整流回路への給電開始から所定時間の経過後に共
通接点を常開側接点に接続するとともに給電が停止する
まで共通接点を常開側接点に接続し続け、給電停止後に
共通接点を常閉側接点に接続するようにリレーを制御す
る制御回路を設けたことを特徴とする。According to a third aspect of the present invention, a current limiting resistor for preventing an inrush current to the load circuit is inserted between the rectifier circuit and the smoothing capacitor, and a common contact is provided at a connection point between the current limiting resistor and one end of the smoothing capacitor. A normally-open side contact of a relay with a double-throw type contact connected to is connected to the connection point between the current limiting resistor and the rectifier circuit, and one end is connected to the connection point between the rectifier circuit and the other end of the smoothing capacitor. Connect the normally closed contact of the relay to the other end of the relay, connect the common contact to the normally open contact after the lapse of a predetermined time from the start of power supply to the rectifier circuit, and make the common contact the normally open contact until the power supply stops. It is characterized in that a control circuit for controlling the relay is provided so as to keep the connection and connect the common contact to the normally closed contact after the power supply is stopped.

【０００９】請求項４の発明は、整流回路と平滑コンデ
ンサとの間に負荷回路への突入電流を防止する限流用抵
抗とリレーの常開接点との並列回路を挿入し、負荷回路
の出力電圧を検出する電圧検出部による検出電圧が所定
電圧に達するとオンになるスイッチング素子とブレーキ
抵抗との直列回路を平滑コンデンサに並列接続し、スイ
ッチング素子にリレーの常閉接点を並列接続し、整流回
路への給電開始から所定時間の経過後に常開接点をオン
にするとともに給電が停止するまで常開接点がオンに保
ち、給電停止後に常閉接点をオンにするようにリレーを
制御する制御回路を設けたことを特徴とする。According to a fourth aspect of the present invention, a parallel circuit of a current limiting resistor for preventing an inrush current to the load circuit and a normally open contact of the relay is inserted between the rectifier circuit and the smoothing capacitor, and an output voltage of the load circuit is inserted. A voltage detector that detects the voltage is connected to a smoothing capacitor in parallel with a series circuit of a switching element and a brake resistor that turn on when the voltage reaches a specified voltage, and a normally closed contact of a relay is connected in parallel to the switching element to form a rectifier circuit. A control circuit that controls the relay to turn on the normally open contact after a lapse of a predetermined time from the start of power supply to the relay and keep the normally open contact on until power supply stops, and turn on the normally closed contact after power supply is stopped. It is characterized by being provided.

【００１０】[0010]

【作用】請求項１の発明の構成は、整流回路と平滑コン
デンサとの間に限流用抵抗と第１のスイッチ要素との並
列回路を挿入し、さらに平滑コンデンサに対して放電用
抵抗と第２のスイッチ要素との直列回路を並列接続して
いるのであって、整流回路への給電開始直後には第１の
スイッチ要素をオフにすることで、限流用抵抗を挿入し
た形で負荷回路への給電を行ない、負荷回路側に電動機
や白熱電球などが設けられている場合の起動時における
突入電流の発生を抑制することができる。また、整流回
路への給電開始から所定時間の経過後に第１のスイッチ
要素をオンにすることで、負荷回路側の動作が定常状態
になると限流用抵抗を通さずに負荷回路に給電すること
で無駄な電力消費を防止できるのである。さらに、整流
回路への給電が停止すると第２のスイッチ要素をオンに
することによって、平滑コンデンサに対して放電用抵抗
を並列接続することになり、負荷回路への給電中には放
電用抵抗を外した状態で無駄な電力消費を発生させない
ようにしながらも、負荷回路への給電を停止させるとき
には放電用抵抗を通して平滑コンデンサの電荷を放電す
ることができるのである。すなわち、保守点検時の平滑
コンデンサの放電に対する要求を満たしながらも、負荷
回路への給電中の無駄な電力消費を発生させず、しかも
放電用抵抗への通電時間を短くすることによって電力容
量の小さいものを用いることができ、結果的に製造コス
トの低減を図ることができるのである。According to the first aspect of the invention, the parallel circuit of the current limiting resistor and the first switch element is inserted between the rectifier circuit and the smoothing capacitor, and the discharging resistor and the second resistor are connected to the smoothing capacitor. Since the series circuit with the switch element of is connected in parallel, the first switch element is turned off immediately after the power supply to the rectifier circuit is started, and the current limiting resistor is inserted to the load circuit. It is possible to supply power and suppress the generation of an inrush current at the time of startup when an electric motor, an incandescent light bulb, etc. are provided on the load circuit side. Further, by turning on the first switch element after a lapse of a predetermined time from the start of power supply to the rectifier circuit, when the operation on the load circuit side becomes a steady state, power is supplied to the load circuit without passing through the current limiting resistor. It is possible to prevent wasteful power consumption. Further, when the power supply to the rectifier circuit is stopped, the second switch element is turned on to connect the discharging resistor in parallel to the smoothing capacitor, and the discharging resistor is connected during the power supply to the load circuit. It is possible to discharge the electric charge of the smoothing capacitor through the discharging resistor when stopping the power supply to the load circuit while preventing unnecessary power consumption in the removed state. That is, while satisfying the requirement for discharging the smoothing capacitor at the time of maintenance and inspection, unnecessary power consumption is not generated during power supply to the load circuit, and the power supply capacity is small by shortening the energization time to the discharge resistor. It is possible to use the ones, and as a result, it is possible to reduce the manufacturing cost.

【００１１】請求項２の発明の構成は、常閉接点と常開
接点とを有するリレーを用いることで、突入電流を防止
する制御と平滑コンデンサの放電の制御とを１つのリレ
ーで一括して行なうことができるようにしたものであっ
て、限流用抵抗にはリレーの常開接点を並列接続し、放
電用抵抗にはリレーの常閉接点を直列接続しているので
あり、整流回路への給電を開始すると、常閉接点がオン
になるとともに常開接点がオフになって、限流用抵抗が
挿入されることにより突入電流が防止される。この間、
平滑コンデンサに対して放電用抵抗が並列接続される
が、整流回路への給電開始から所定時間が経過して負荷
回路が定常状態になると、常開接点がオンになって限流
用抵抗を通さずに負荷回路に給電できるようになること
により、常閉接点がオフになり、放電用抵抗が外される
ことになる。すなわち、放電用抵抗は整流回路への通電
開始直後には一時的に平滑用コンデンサに並列接続され
るが、負荷回路の定常動作中には平滑用コンデンサから
切り離されて機能せず、請求項１の発明と同様に、無駄
な電力消費を発生させることがないのである。さらに、
給電が停止すると常開接点がオフになり、このとき常閉
接点がオンになるから、平滑コンデンに対して放電用抵
抗が並列接続され、放電用抵抗を通して平滑コンデンサ
の電荷を放電させることができるのである。このよう
に、放電用抵抗には給電開始直後と給電停止後とに電流
が短時間ずつ流れるだけであるから、電力容量の小さい
ものを用いることができ、結果的に製造コストの低減に
つながる。しかも、請求項２の発明では、常開接点と常
閉接点とを備える１個のリレーで突入電流の防止と平滑
コンデンサの放電とを一括して制御することができ、部
品点数が少なくなるのである。According to the second aspect of the present invention, by using the relay having the normally closed contact and the normally open contact, the control for preventing the inrush current and the control for the discharging of the smoothing capacitor are collectively performed by one relay. The current limiting resistor is connected in parallel with the normally open contact of the relay, and the discharging resistor is connected in series with the normally closed contact of the relay. When power supply is started, the normally-closed contact is turned on and the normally-open contact is turned off, and the rush current is prevented by inserting the current limiting resistor. During this time,
A discharge resistor is connected in parallel with the smoothing capacitor, but if the load circuit enters a steady state for a predetermined time after the start of power supply to the rectifier circuit, the normally open contact turns on and the current limiting resistor does not pass. By being able to supply power to the load circuit, the normally closed contact is turned off and the discharge resistor is removed. That is, the discharging resistor is temporarily connected in parallel with the smoothing capacitor immediately after the rectifier circuit is energized, but is disconnected from the smoothing capacitor and does not function during the steady operation of the load circuit. As in the invention described above, useless power consumption does not occur. further,
When the power supply is stopped, the normally open contact is turned off, and at this time the normally closed contact is turned on. Therefore, the discharging resistor is connected in parallel to the smoothing capacitor, and the electric charge of the smoothing capacitor can be discharged through the discharging resistor. Of. As described above, as the discharging resistor, a current only flows for a short period of time immediately after the start of power feeding and after the stop of power feeding, a resistor having a small power capacity can be used, and as a result, the manufacturing cost can be reduced. Moreover, in the invention of claim 2, the prevention of the inrush current and the discharge of the smoothing capacitor can be collectively controlled by one relay having the normally open contact and the normally closed contact, and the number of parts is reduced. is there.

【００１２】請求項３の発明の構成によれば、双投型接
点を有する１個のリレーを用いて、平滑コンデンサと限
流用抵抗との接続点に共通接点を接続し、常開側接点を
限流用抵抗と整流回路との接続点に接続し、常閉側接点
を整流回路と平滑コンデンサの他端との接続点に一端を
接続した放電用抵抗の他端に接続しているから、常閉側
接点に接続すれば平滑コンデンサに放電用抵抗を並列接
続して平滑コンデンサの放電が行なわれ、また同時に整
流回路から負荷回路への電路に限流用抵抗を挿入して突
入電流を防止することができる。しかして、整流回路へ
の給電開始直後には常閉側接点に接続して突入電流を防
止し、給電開始から所定時間が経過して負荷回路が定常
状態になると常開側接点に接続して限流用抵抗を通さず
に負荷回路に給電できるようにするとともに、放電用抵
抗を平滑コンデンサから外して無駄な電力消費を発生さ
せないようにすることができる。整流回路への給電が停
止すれば、常閉側接点に接続して平滑コンデンサに放電
用抵抗を並列接続し、平滑コンデンサの電荷を短時間で
放電させることができるのである。このように、請求項
３の発明はリレーの接点構成が異なる点を除けば、請求
項２の発明と同様であり、突入電流の防止、負荷回路の
定常動作中の放電用抵抗による無駄な電力消費の防止、
給電停止後の平滑コンデンサの電荷の放電を行なうこと
ができ、放電用抵抗として電力容量の小さいものを用い
ることができるのである。しかも、１個の接点のみで上
述した制御が可能になるから、２個の接点を持つリレー
を用いた請求項２の発明よりも小形なリレーを用いるこ
とが可能になる。According to the structure of the third aspect of the present invention, by using one relay having a double throw type contact, the common contact is connected to the connection point between the smoothing capacitor and the current limiting resistor, and the normally open side contact is connected. It is connected to the connection point between the current limiting resistor and the rectifier circuit, and the normally closed contact is connected to the other end of the discharge resistor whose one end is connected to the connection point between the rectifier circuit and the other end of the smoothing capacitor. If connected to the contact on the closed side, a smoothing capacitor is connected in parallel with a discharging resistor to discharge the smoothing capacitor.At the same time, a current limiting resistor should be inserted in the circuit from the rectifier circuit to the load circuit to prevent inrush current. You can Immediately after the power supply to the rectifier circuit is started, it is connected to the normally-closed side contact to prevent the inrush current. It is possible to supply power to the load circuit without passing through the current-limiting resistor, and remove the discharging resistor from the smoothing capacitor to prevent wasteful power consumption. When the power supply to the rectifier circuit is stopped, the smoothing capacitor is connected in parallel with the discharging resistor connected to the normally-closed side contact, and the electric charge of the smoothing capacitor can be discharged in a short time. As described above, the invention of claim 3 is the same as the invention of claim 2 except that the contact configuration of the relay is different, and the inrush current is prevented, and the wasted power due to the discharging resistance during the steady operation of the load circuit is used. Prevention of consumption,
It is possible to discharge the electric charge of the smoothing capacitor after the power supply is stopped, and it is possible to use a discharge resistor having a small power capacity. Moreover, since the above-mentioned control is possible with only one contact, it is possible to use a smaller relay than the invention of claim 2 which uses a relay having two contacts.

【００１３】請求項４の発明の構成によれば、負荷回路
の出力電圧を検出する電圧検出部を備え電圧検出部によ
る検出電圧が所定電圧に達するとオンになるスイッチン
グ素子とブレーキ抵抗との直列回路を平滑コンデンサに
並列接続し、さらに限流用抵抗にリレーの常開接点を並
列接続し、スイッチング素子に並列にリレーの常閉接点
を並列接続しているのであって、負荷回路側に電動機を
用いている場合に電動機への給電停止後に慣性で生じる
回生電流を熱エネルギーに変えて電動機を短時間で停止
させる目的で用いられているブレーキ抵抗を平滑コンデ
ンサの放電用抵抗として兼用しているのである。すなわ
ち、整流回路への給電開始直後では常開接点がオフであ
って限流用抵抗が有効に機能することにより突入電流が
防止され、この間、常閉接点はオンであり負荷回路の出
力電圧が低くスイッチング素子もオンであるから、ブレ
ーキ抵抗が平滑コンデンサに並列接続されることにな
る。整流回路への給電開始から所定時間が経過して負荷
回路が定常状態になると、リレーの常開接点がオンにな
って限流用抵抗が機能しなくなり、また常閉接点がオフ
になるとともに負荷回路の出力電圧の上昇によってスイ
ッチング素子もオフになるから、放電用抵抗は平滑コン
デンサから外され、無駄な電力消費が生じないのであ
る。さらに、整流回路への給電が停止すれば負荷回路の
出力電圧も低下するから、常閉接点がオンになるととも
にスイッチング素子がオンになり、平滑コンデンサにブ
レーキ抵抗が並列接続されて、平滑コンデンサの電荷の
放電と回生電流の消費とがブレーキ抵抗によって行なわ
れる。この構成では、放電用抵抗をブレーキ抵抗で兼用
しているから、突入電流の防止機能とブレーキ抵抗とを
備える回路構成であれば、リレーを接点構成の異なるも
のに設計変更するとともに、ブレーキ抵抗に直列接続さ
れたスイッチング素子に対してリレーの一方の接点（常
閉接点）を並列接続するだけのごく簡単な回路変更で、
平滑コンデンサの放電に関する要求を満たすことができ
るのである。According to the structure of the fourth aspect of the present invention, a series of a switching element and a brake resistor, which is provided with a voltage detecting section for detecting the output voltage of the load circuit, is turned on when the voltage detected by the voltage detecting section reaches a predetermined voltage. The circuit is connected in parallel with the smoothing capacitor, the normally open contact of the relay is connected in parallel with the current limiting resistor, and the normally closed contact of the relay is connected in parallel with the switching element. When used, the brake resistance used to stop the motor in a short time by converting the regenerative current generated by inertia after the power supply to the motor is stopped into heat energy is also used as the discharging resistance of the smoothing capacitor. is there. That is, immediately after the start of power supply to the rectifier circuit, the normally open contact is off and the current limiting resistor effectively functions to prevent inrush current.During this time, the normally closed contact is on and the output voltage of the load circuit is low. Since the switching element is also on, the brake resistor is connected in parallel with the smoothing capacitor. When the load circuit enters a steady state after a lapse of a predetermined time from the start of power supply to the rectifier circuit, the normally open contact of the relay turns on, the current limiting resistor does not function, and the normally closed contact turns off and the load circuit Since the switching element is also turned off due to the increase in the output voltage of, the discharging resistor is removed from the smoothing capacitor, and unnecessary power consumption does not occur. Furthermore, if the power supply to the rectifier circuit is stopped, the output voltage of the load circuit also drops, so the normally closed contact turns on and the switching element turns on, and the braking resistor is connected in parallel to the smoothing capacitor, The discharge of electric charge and the consumption of regenerative current are performed by the brake resistor. In this configuration, since the discharge resistor is also used as the brake resistor, if the circuit configuration has a function to prevent the inrush current and the brake resistor, the relay design can be changed to one with a different contact configuration and the brake resistor can be used. With a very simple circuit change, only one contact (normally closed contact) of the relay is connected in parallel to the switching element connected in series.
It is possible to meet the requirements for discharging the smoothing capacitor.

【００１４】[0014]

【実施例】【Example】

（実施例１）本実施例は、請求項１の発明に対応するも
のであって、図１に示すように、図５に示した従来構成
に比較すると、放電用抵抗ＲD にスイッチ要素としての
リレーＲｙD の接点ｒD を直列接続した点が相違する。
さらに具体的に説明すると、商用電源ＡＣを電源スイッ
チＳＷを介して整流回路ＲＥに接続し、整流回路ＲＥで
商用電源ＡＣを整流した後に平滑コンデンサＣで平滑す
る。また、平滑コンデンサＣにより得られた直流は、イ
ンバータ回路を構成する主回路ＩＮＶで交番電力に変換
されて負荷としての電動機Ｍに供給される。ここで、主
回路ＩＮＶが負荷回路となる。一方、整流回路ＲＥの入
力電圧と出力電圧とは、それぞれ電圧検出回路ＶＳIN，
ＶＳOUT により検出され、それぞれ基準電圧と比較され
る。比較結果は、制御回路ＣＮに入力され、制御回路Ｃ
Ｎでは両電圧検出回路ＶＳIN，ＶＳOUT への入力がとも
に基準電圧以上であれば商用電源ＡＣからの給電がなさ
れていると判断して２個のリレーＲｙL ，ＲｙD を制御
する。(Example 1) This example, which corresponds to the invention of claim 1, as shown in FIG. 1, when compared to the conventional configuration shown in FIG. 5, as the switch element to the discharge resistor R D The difference is that the contact r D of the relay Ry D of is connected in series.
More specifically, the commercial power source AC is connected to the rectifier circuit RE via the power switch SW, the commercial power source AC is rectified by the rectifier circuit RE, and then smoothed by the smoothing capacitor C. Further, the direct current obtained by the smoothing capacitor C is converted into alternating electric power by the main circuit INV forming the inverter circuit and supplied to the electric motor M as a load. Here, the main circuit INV serves as a load circuit. On the other hand, the input voltage and the output voltage of the rectifier circuit RE are the voltage detection circuits VS IN and VS IN , respectively.
Detected by VS OUT and compared with the reference voltage respectively. The comparison result is input to the control circuit CN and the control circuit C
In N, if the inputs to both voltage detection circuits VS IN and VS OUT are both higher than the reference voltage, it is determined that power is being supplied from the commercial power supply AC, and the two relays Ry L and Ry D are controlled.

【００１５】ところで、整流回路ＲＥの出力端間には平
滑コンデンサＣと限流用抵抗ＲL との直列回路が接続さ
れ、限流用抵抗ＲL にはスイッチ要素としての一方のリ
レーＲｙL の接点ｒL が並列接続される。また、平滑コ
ンデンサＣには、上述したように放電用抵抗ＲD と他方
のリレーＲｙD の接点ｒD との直列回路が並列接続され
る。A series circuit of a smoothing capacitor C and a current limiting resistor R L is connected between the output terminals of the rectifier circuit RE, and the current limiting resistor R L has a contact r of one relay Ry L as a switching element. L is connected in parallel. Further, the smoothing capacitor C is connected in parallel with the series circuit of the discharging resistor R D and the contact r D of the other relay Ry D as described above.

【００１６】次に制御回路ＣＮの動作を説明する。電源
スイッチＳＷがオンになって商用電源ＡＣからの給電が
開始されたことが電圧検出回路ＶＳIN，ＶＳOUT の出力
によって制御回路ＣＮで検出されると、両リレーＲ
ｙL ，ＲｙD の接点ｒL ，ｒD をともにオフにするよう
に制御する。すなわち、限流用抵抗ＲL が有効に機能す
るとともに放電用抵抗ＲD が平滑コンデンサＣから切り
離された状態になる。したがって、主回路ＩＮＶへの通
電電流が限流用抵抗ＲL により制限されて突入電流が防
止される。Next, the operation of the control circuit CN will be described. When the control circuit CN detects from the outputs of the voltage detection circuits VS IN and VS OUT that the power switch SW is turned on and the power supply from the commercial power source AC is started, both relays R
Both the contacts r L and r D of y L and Ry D are controlled to be turned off. That is, the current limiting resistor R L functions effectively and the discharging resistor R D is disconnected from the smoothing capacitor C. Therefore, the current flowing to the main circuit INV is limited by the current limiting resistor RL, and the inrush current is prevented.

【００１７】その後、主回路ＩＮＶないし電動機Ｍが定
常状態になって突入電流が発生しない程度の所定時間が
経過すると（制御回路ＣＮに設けたタイマにより時限す
る）、リレーＲｙL の接点ｒL をオフにするように制御
する。したがって、整流回路ＲＥの出力は限流用抵抗Ｒ
L を通らずに主回路ＩＮＶに供給されるようになり、限
流用抵抗ＲL での電圧降下がなくなる。また、リレーＲ
ｙD の接点ｒD はオフに保たれるから、放電用抵抗ＲD
には電流が流れず無駄な電力消費が生じないのである。After that, when the main circuit INV or the electric motor M is in a steady state and a predetermined time has passed until a rush current is not generated (timed by a timer provided in the control circuit CN), the contact r L of the relay Ry L is closed. Control to turn off. Therefore, the output of the rectifier circuit RE is the current limiting resistor R
The voltage is supplied to the main circuit INV without passing through L , and the voltage drop at the current limiting resistor R L is eliminated. Also, relay R
Since the contact r D of y D is kept off, the discharge resistor R D
No current flows through the device, and no unnecessary power consumption occurs.

【００１８】電源スイッチＳＷをオフにしたり商用電源
ＡＣが遮断されると、整流回路ＲＥへの給電が停止した
ことを電圧検出回路ＶＳIN，ＶＳOUT の出力によって制
御回路ＣＮが検出するから、制御回路ＣＮではリレーＲ
ｙD の接点ｒD をオンにするように制御し、放電用抵抗
ＲD を平滑コンデンサＣに並列接続する。すなわち、給
電停止後には平滑コンデンサＣの電荷が放電用抵抗ＲD
を通して放電され、平滑コンデンサＣの端子電圧が短時
間で低下するのである。このように、放電用抵抗ＲD に
は給電停止後の短時間しか電流が流れないから、放電用
抵抗ＲD の発熱量は少ないのであって、放電用抵抗ＲD
として電力容量の小さい安価なものを用いることができ
るのである。ここにおいて、リレーＲｙL ，ＲｙD とし
ては、一般的な電磁継電器を用いたり、電磁接触器を用
いたりすることができる。なお、上記実施例では、整流
回路ＲＥへの給電開始直後では接点ｒL ，ｒD をともに
オフにしているが、接点ｒL のみをオフにしてもよく、
その場合には、リレーＲｙ L の常開接点を接点ｒL と
し、リレーＲｙD の常閉接点を接点ｒD として用いるよ
うにしてもよい。Power switch SW is turned off or commercial power source
When AC is cut off, power supply to the rectifier circuit RE is stopped
That the voltage detection circuit VSIN, VSOUTControlled by the output of
Since the control circuit CN detects it, the control circuit CN relays R
yDContact point rDControl to turn on the discharge resistor
RDIs connected in parallel to the smoothing capacitor C. That is, salary
After the power is stopped, the electric charge of the smoothing capacitor C is changed to the discharging resistor R.D
When the terminal voltage of smoothing capacitor C is short
It drops in between. In this way, the discharge resistor RDTo
Is for discharging because current flows only for a short time after power supply is stopped.
Resistance RDSince the amount of heat generated by theD
You can use an inexpensive one with a small power capacity as
It is. Here, the relay RyL, RyDage
Use a general electromagnetic relay or an electromagnetic contactor.
You can come and go. In the above embodiment, the rectification
Immediately after the start of power supply to the circuit RE, the contact point rL, RDTogether with
Turned off, but contact rLYou can turn off only
In that case, relay Ry LNormally open contact of contact rLWhen
And relay RyDNormally closed contact of contact rDI will use it as
You may ask.

【００１９】（実施例２）本実施例は請求項２の発明に
対応するものであって、実施例１では、限流用抵抗ＲL
に並列接続されが接点ｒD と放電用抵抗ＲD に直列接続
された接点ｒL とを、それぞれ個別のリレーＲｙL ，Ｒ
ｙD の接点ｒL ，ｒD としていたが、本実施例では図２
に示すように、１つのリレーＲｙにおける常開接点ｒNO
と常閉接点ｒNCとを、実施例１の接点ｒL ，ｒD に代え
て用いている。すなわち、限流用抵抗ＲL には常開接点
ｒNOを並列接続し、放電用抵抗ＲD には常閉接点ｒNCを
直列接続している。(Embodiment 2) This embodiment corresponds to the invention of claim 2, and in Embodiment 1, the current limiting resistor R L is used.
In a contact r L in series with the parallel connected but contacts r D and discharge resistor R D, each individual relay Ry L, R
Although the contacts r L and r D of y D were used, in this embodiment, they are shown in FIG.
As shown in, normally open contact r NO in one relay Ry
And the normally closed contact r NC are used instead of the contacts r L and r D of the first embodiment. That is, the normally-open contact r NO is connected in parallel to the current limiting resistor R L, and the normally-closed contact r NC is connected in series to the discharging resistor R D.

【００２０】制御回路ＣＮでは、電源スイッチＳＷがオ
ンになったときに、電圧検出回路ＶＳIN，ＶＳOUT の出
力によって整流回路ＲＥへの給電開始を検出した時点で
は、常開接点ｒNOをオフにしておき、限流用抵抗ＲL を
整流回路ＲＥと主回路ＩＮＶとの間に挿入することで突
入電流を防止する。その後、主回路ＩＮＶないし電動機
Ｍが定常状態になる程度の所定時間が経過すると、常開
接点ｒNOをオンにして限流用抵抗ＲL を通さずに整流回
路ＲＥから主回路ＩＮＶへの給電を行なう。このときに
は、常閉接点ｒNCはオフであるから放電用抵抗ＲD には
通電されず、無駄な電力消費は生じないのである。In the control circuit CN, when the power switch SW is turned on and the start of power supply to the rectifier circuit RE is detected by the outputs of the voltage detection circuits VS IN and VS OUT , the normally open contact r NO is turned off. Then, the current limiting resistor R L is inserted between the rectifier circuit RE and the main circuit INV to prevent an inrush current. After that, when a predetermined time such that the main circuit INV or the electric motor M reaches a steady state has passed, the normally open contact r NO is turned on and power is supplied from the rectifier circuit RE to the main circuit INV without passing through the current limiting resistor R L. To do. At this time, the normally closed contact r NC is off, so that the discharge resistor R D is not energized, and unnecessary power consumption does not occur.

【００２１】電圧検出回路ＶＳIN，ＶＳOUT の出力によ
って整流回路ＲＥへの給電の停止を検出すると、制御回
路ＣＮはリレーＲｙの常閉接点ｒNCをオンにし、放電用
抵抗ＲD を平滑コンデンサＣに並列接続する。ここで、
整流回路ＲＥからの給電が停止しているから常開接点ｒ
NOがオフであっても限流用抵抗ＲL は機能しない。この
ように、給電停止後には放電用抵抗ＲD を平滑コンデン
サＣに並列接続することによって、平滑コンデンサＣの
電荷を放電用抵抗ＲD を通して放電させることができる
から、平滑コンデンサＣの端子電圧を短時間で低下させ
ることができるのである。When the stop of the power supply to the rectifier circuit RE is detected by the outputs of the voltage detection circuits VS IN and VS OUT , the control circuit CN turns on the normally closed contact r NC of the relay Ry, and the discharging resistor R D is smoothed by a smoothing capacitor. Connect to C in parallel. here,
Since the power supply from the rectifier circuit RE is stopped, the normally open contact r
The current limiting resistor RL does not function even when NO is off. Thus, by connecting the discharging resistor R D to the smoothing capacitor C in parallel after the power supply is stopped, the electric charge of the smoothing capacitor C can be discharged through the discharging resistor R D , so that the terminal voltage of the smoothing capacitor C is changed. It can be lowered in a short time.

【００２２】本実施例では、整流回路ＲＥへの給電停止
後だけではなく、給電開始直後にも放電用抵抗ＲD に通
電されるが、放電用抵抗ＲD への通電時間は短時間であ
るから、電力容量の大きなものは不要である。また、実
施例１の構成に比較すると１個のリレーＲｙを用いるだ
けであるから、突入電流の防止用にリレーを用いていれ
ば、常開接点ｒNOに加えて常閉接点ｒNCを持つリレーＲ
ｙに取り替え、かつ放電用抵抗ＲD に常閉接点ｒNCを直
列接続するだけの簡単な変更で、突入電流の防止と平滑
コンデンサＣの放電とを行なうことができるのである。
他の構成および動作は実施例１と同様である。In the present embodiment, the discharge resistor R D is energized not only after the power supply to the rectifier circuit RE is stopped but also immediately after the power supply is started, but the energization time to the discharge resistor R D is short. Therefore, a large power capacity is unnecessary. Further, since only one relay Ry is used as compared with the configuration of the first embodiment, if a relay is used to prevent inrush current, it has a normally closed contact r NC in addition to the normally open contact r NO. Relay R
The inrush current can be prevented and the smoothing capacitor C can be discharged by a simple change such that it is replaced with y and the normally closed contact r NC is connected in series to the discharge resistor R D.
Other configurations and operations are the same as those of the first embodiment.

【００２３】（実施例３）本実施例は請求項３の発明に
対応するものであって、実施利２では常開接点ｒ NOと常
閉接点ｒNCとを個別に持つリレーＲｙを用いていたが、
本実施例では図３に示すように双投型接点ｒSWを有する
リレーＲｙを用いた例を示す。すなわち、平滑コンデン
サＣと限流用抵抗ＲL の一端との接続点に双投型接点ｒ
SW共通接点を接続し、常開側接点ａを整流回路ＲＥと限
流用抵抗ＲL との接続点に接続し、さらに常閉側接点ｂ
を放電用抵抗ＲD の一端に接続したものであって、放電
用抵抗ＲD の他端は整流回路ＲＥと平滑コンデンサＣと
の接続点に接続される。(Embodiment 3) This embodiment is the invention of claim 3.
Corresponding one, normally used contact r NOAnd always
Closed contact rNCI used a relay Ry that has and
In this embodiment, as shown in FIG. 3, a double throw contact rSWHave
An example using the relay Ry will be shown. That is, smooth condensate
SA C and current limiting resistor RLDouble throw contact r at the connection point with one end of
SWConnect the common contact and limit the normally open contact a to the rectifier circuit RE.
Diversion resistance RLConnected to the connection point with, and the normally closed contact b
Discharge resistor RDConnected to one end of the
Resistance RDThe other end of the rectifier circuit RE and the smoothing capacitor C
Connected to the connection point.

【００２４】リレーＲｙの接点構成が異なる点を除け
ば、制御回路ＣＮの動作は実施例２と同様であって、整
流回路ＲＥへの給電開始時にはリレーＲｙの共通接点は
常閉側接点ｂに接続され、限流用抵抗ＲL が整流回路Ｒ
Ｅと主回路ＩＮＶとの間に挿入され、突入電流が防止さ
れる。また、給電開始から所定時間の経過後にはリレー
Ｒｙの共通接点は常開側接点ａに接続され、限流用抵抗
ＲL を通さずに主回路ＩＮＶに給電され、また放電用抵
抗ＲD は平滑コンデンサＣから切り離される。The operation of the control circuit CN is the same as that of the second embodiment except that the contact configuration of the relay Ry is different, and the common contact of the relay Ry is the normally closed contact b when the power supply to the rectifier circuit RE is started. The current limiting resistor R L is connected and the rectifier circuit R
It is inserted between E and the main circuit INV to prevent inrush current. Further, after a lapse of a predetermined time from the start of power supply, the common contact of the relay Ry is connected to the normally open side contact a, the power is supplied to the main circuit INV without passing through the current limiting resistor R L, and the discharge resistor R D is smoothed. It is separated from the capacitor C.

【００２５】整流回路ＲＥへの給電が停止すれば、リレ
ーＲｙの共通接点は常閉側接点ｂに接続され、放電用抵
抗ＲD が平滑コンデンサＣに並列接続されることによっ
て平滑コンデンサＣの電荷が放電用抵抗ＲD を通して放
電される。上述のように、放電用抵抗ＲD は整流回路Ｒ
Ｅへの給電開始直後と給電停止後の短時間だけ通電され
るから、無駄な電力消費がなく、また電力容量の小さい
ものを用いることができるのである。しかも、リレーＲ
ｙとして双投型接点ｒSWを持つものを用いており、実施
例２のように常開接点ｒNOと常閉接点ｒNCとの２つの接
点を持つ場合に比較すると小形のリレーＲｙを用いるこ
とが可能になる。他の構成および動作は実施例２と同様
である。When the power supply to the rectifier circuit RE is stopped, the common contact of the relay Ry is connected to the normally closed contact b, and the discharging resistor R D is connected in parallel to the smoothing capacitor C, so that the charge of the smoothing capacitor C is charged. Are discharged through the discharge resistor R D. As described above, the discharge resistor R D is the rectifier circuit R
Since power is supplied to E immediately after the start of power supply and for a short time after power supply is stopped, wasteful power consumption and a small power capacity can be used. Moreover, relay R
A relay having a double throw contact r SW is used as y, and a small relay Ry is used as compared with the case of having two contacts of normally open contact r NO and normally closed contact r NC as in the second embodiment. It will be possible. Other configurations and operations are similar to those of the second embodiment.

【００２６】（実施例４）本実施例は請求項４の発明に
対応するものであって、主回路ＩＮＶの出力により電動
機Ｍに給電する場合にとくに有効な例であって、図４に
示すように、実施例２の構成における放電用抵抗ＲD に
代えてブレーキ抵抗ＲB を用いている。ブレーキ抵抗Ｒ
B にはスイッチング素子としてのトランジスタＱのコレ
クタ−エミッタ間が直列接続され、リレーＲｙの常閉接
点ｒNCはトランジスタＱのコレクタ−エミッタ間に並列
接続される。トランジスタＱは主回路ＩＮＶの出力電圧
を監視する電圧検出回路ＶＳM によりオン・オフが制御
されており、出力電圧が基準電圧以下になるとトランジ
スタＱがオンになる。すなわち、電動機Ｍでは給電が停
止した後に慣性で回転が継続することによって回生電流
が生じることが知られており、この回生電流を熱エネル
ギーに変えて消費させて電動機Ｍの回転を迅速に停止さ
せるために、電圧検出回路ＶＳM の検出電圧の低下によ
って電動機Ｍへの給電停止を検出するとトランジスタＱ
をオンにしてブレーキ抵抗ＲB に回生電流を流すのであ
る。(Embodiment 4) This embodiment corresponds to the invention of claim 4 and is a particularly effective example when power is supplied to the electric motor M by the output of the main circuit INV, and is shown in FIG. As described above, the brake resistor R B is used in place of the discharge resistor R D in the configuration of the second embodiment. Brake resistance R
The collector-emitter of the transistor Q as a switching element is connected in series to B, and the normally closed contact r NC of the relay Ry is connected in parallel between the collector-emitter of the transistor Q. The transistor Q is on / off controlled by a voltage detection circuit VS M that monitors the output voltage of the main circuit INV, and the transistor Q is turned on when the output voltage falls below the reference voltage. That is, in the electric motor M, it is known that rotation continues due to inertia after power supply is stopped, and a regenerative current is generated. The regenerative current is converted into heat energy and consumed to quickly stop the rotation of the electric motor M. Therefore, when the stop of the power supply to the electric motor M is detected by the decrease in the detection voltage of the voltage detection circuit VS M , the transistor Q
Is turned on and a regenerative current is passed through the brake resistor R B.

【００２７】上記構成では、常開接点ｒNOおよび常閉接
点ｒNCは実施例２と同様に制御されるのであって、整流
回路ＲＥへの給電開始直後には整流回路ＲＥと主回路Ｉ
ＮＶとの間に限流用抵抗ＲL が挿入されて突入電流が防
止され、給電開始から所定時間後には常開接点ｒNOがオ
ンになるとともに常閉接点ｒNCがオフになる。このと
き、主回路ＩＮＶの出力電圧が高くなってトランジスタ
Ｑがオフになる。したがって、主回路ＩＮＶの定常動作
中には限流用抵抗ＲL を通さずに整流回路ＲＥから主回
路ＩＮＶへの給電がなされ、ブレーキ抵抗ＲB は平滑コ
ンデンサＣから切り離されて無駄な電力消費が生じない
のである。In the above configuration, the normally open contact r NO and the normally closed contact r NC are controlled in the same manner as in the second embodiment, and immediately after the power supply to the rectifier circuit RE is started, the rectifier circuit RE and the main circuit I are connected.
A current limiting resistor R L is inserted between the NV and the rush current to prevent an inrush current, and the normally open contact r NO is turned on and the normally closed contact r NC is turned off after a predetermined time from the start of power supply. At this time, the output voltage of the main circuit INV becomes high and the transistor Q is turned off. Therefore, during steady operation of the main circuit INV, power is supplied from the rectifier circuit RE to the main circuit INV without passing through the current limiting resistor R L , and the brake resistor R B is disconnected from the smoothing capacitor C, resulting in unnecessary power consumption. It does not happen.

【００２８】一方、整流回路ＲＥへの給電が停止すれ
ば、常閉接点ｒNCがオンになってブレーキ抵抗ＲB が平
滑コンデンサＣに並列接続され、ブレーキ抵抗B を通し
て平滑コンデンサＣの電荷が放電されるのである。ま
た、主回路ＩＮＶの出力電圧が低下することによってト
ランジスタＱもオンになる。このようにして、給電停止
後に平滑コンデンサＣの端子電圧を短時間で低下させる
ことができ、しかもブレーキ抵抗ＲB には整流回路ＲＥ
への給電開始直後と給電停止後とに短時間通電されるだ
けであるから、電力容量の小さい安価なものを用いるこ
とができる。On the other hand, when the power supply to the rectifying circuit RE is stopped, the normally closed contact r NC is turned on, the brake resistor R B is connected in parallel with the smoothing capacitor C, and the charge of the smoothing capacitor C is discharged through the brake resistor B. Is done. Also, the transistor Q is turned on as the output voltage of the main circuit INV decreases. In this way, the terminal voltage of the smoothing capacitor C can be reduced in a short time after the power supply is stopped, and the rectifier circuit RE is connected to the brake resistor R B.
Since the power is only energized for a short time immediately after the start of power supply to and after the power supply is stopped, an inexpensive power supply with a small power capacity can be used.

【００２９】本実施例の構成では、突入電流を防止する
ための限流用抵抗ＲL と、回生電流を流すためのブレー
キ抵抗ＲB とを備えた構成であれば、リレーＲｙの接点
構成に変更を加えるだけのごく簡単な変更で、突入電流
の防止と電動機Ｍの電気ブレーキとの機能に加えて、平
滑コンデンサＣの放電を行なうことができ、部品点数を
増加させることなく平滑コンデンサＣの放電の機能を追
加することができるのである。他の構成および動作は実
施例２と同様である。In the structure of this embodiment, if the structure is provided with a current limiting resistor R L for preventing an inrush current and a brake resistor R B for flowing a regenerative current, the contact structure of the relay Ry is changed. In addition to the function of preventing the inrush current and the electric brake of the electric motor M, the smoothing capacitor C can be discharged by a very simple change by simply adding The function of can be added. Other configurations and operations are similar to those of the second embodiment.

【００３０】[0030]

【発明の効果】請求項１の発明は、整流回路と平滑コン
デンサとの間に限流用抵抗と第１のスイッチ要素との並
列回路を挿入し、さらに平滑コンデンサに対して放電用
抵抗と第２のスイッチ要素との直列回路を並列接続し、
整流回路への給電中は第２のスイッ要素をオフにしてい
るから、負荷回路への給電中の無駄な電力消費を発生さ
せないという利点を有し、しかも整流回路への給電が停
止すると第２のスイッチ要素をオンにするから、平滑コ
ンデンサに対して放電用抵抗を並列接続することにな
り、負荷回路への給電を停止させるときには放電用抵抗
を通して平滑コンデンサの電荷を放電することができる
という利点がある。その結果、保守点検時の平滑コンデ
ンサの放電に対する要求を満たしながらも、負荷回路へ
の給電中の無駄な電力消費を発生させず、しかも放電用
抵抗への通電時間を短くすることによって電力容量の小
さいものを用いることができ、製造コストの低減を図る
ことができるという効果を奏するのである。According to the invention of claim 1, a parallel circuit of the current limiting resistor and the first switch element is inserted between the rectifier circuit and the smoothing capacitor, and the discharging resistor and the second resistor are connected to the smoothing capacitor. Connect the series circuit with the switch element of in parallel,
Since the second switching element is turned off during the power supply to the rectifier circuit, there is an advantage that unnecessary power consumption is not generated during the power supply to the load circuit. Since the switch element of is turned on, the discharging resistor is connected in parallel to the smoothing capacitor, and when stopping the power supply to the load circuit, the electric charge of the smoothing capacitor can be discharged through the discharging resistor. There is. As a result, while satisfying the requirements for discharging the smoothing capacitor during maintenance and inspection, unnecessary power consumption is not generated during power supply to the load circuit, and the power supply capacity is reduced by shortening the time for energizing the discharging resistor. Therefore, a small product can be used, and the manufacturing cost can be reduced.

【００３１】請求項２の発明は、限流用抵抗にはリレー
の常開接点を並列接続し、放電用抵抗にはリレーの常閉
接点を直列接続し、整流回路への給電開始から所定時間
が経過して負荷回路が定常状態になると、常閉接点がオ
フになり、放電用抵抗が外されるので、放電用抵抗は負
荷回路の定常動作中には平滑用コンデンサから切り離さ
れて機能せず、無駄な電力消費を発生させることがない
という利点がある。また、給電が停止すると常閉接点が
オンになるから、平滑コンデンに対して放電用抵抗が並
列接続され、放電用抵抗を通して平滑コンデンサの電荷
を放電させることができるという利点がある。しかし
て、放電用抵抗には給電開始直後と給電停止後とに電流
が短時間ずつ流れるだけであるから、電力容量の小さい
ものを用いることができ、結果的に製造コストの低減に
つながるという利点があり、しかも常開接点と常閉接点
とを備える１個のリレーで突入電流の防止と平滑コンデ
ンサの放電とを一括して制御することができ、部品点数
が少なくなるという利点を有する。According to a second aspect of the present invention, a normally open contact of the relay is connected in parallel to the current limiting resistor, and a normally closed contact of the relay is connected in series to the discharging resistor, and a predetermined time has elapsed from the start of power supply to the rectifier circuit. When the load circuit reaches a steady state after a certain period of time, the normally closed contact turns off and the discharge resistor is removed.Therefore, the discharge resistor is disconnected from the smoothing capacitor during the steady operation of the load circuit and does not function. However, there is an advantage that wasteful power consumption is not generated. Further, since the normally closed contact is turned on when the power supply is stopped, there is an advantage that the discharging resistor is connected in parallel to the smoothing capacitor and the electric charge of the smoothing capacitor can be discharged through the discharging resistor. However, since the current for the discharge resistor only flows for a short time immediately after the start of power supply and after the power supply is stopped, it is possible to use a resistor with a small power capacity, which results in a reduction in manufacturing cost. In addition, it is possible to collectively control the inrush current prevention and the discharging of the smoothing capacitor with one relay having the normally open contact and the normally closed contact, which has the advantage of reducing the number of parts.

【００３２】請求項３の発明は、双投型接点を有する１
個のリレーを用いて、平滑コンデンサと限流用抵抗との
接続点に共通接点を接続し、常開側接点を限流用抵抗と
整流回路との接続点に接続し、常閉側接点を整流回路と
平滑コンデンサの他端との接続点に一端を接続した放電
用抵抗の他端に接続し、給電開始から所定時間が経過し
て負荷回路が定常状態になると常開側接点に接続して放
電用抵抗を平滑コンデンサから外して無駄な電力消費を
発生させないようにすることができるという利点を有す
る。また、整流回路への給電が停止すれば、常閉側接点
に接続して平滑コンデンサに放電用抵抗を並列接続し、
平滑コンデンサの電荷を短時間で放電させることができ
るという利点がある。しかも、１個の接点のみで上述し
た制御が可能になるから、２個の接点を持つリレーを用
いる場合よりも小形なリレーを用いることが可能になる
という利点がある。The invention of claim 3 has a double throw type contact 1
Using a single relay, connect a common contact to the connection point between the smoothing capacitor and the current limiting resistor, connect the normally open side contact to the connection point between the current limiting resistor and the rectifier circuit, and connect the normally closed side contact to the rectifier circuit. And the other end of the smoothing capacitor, one end of which is connected to the other end of the discharge resistor, and when the load circuit reaches a steady state for a predetermined time after the start of power supply, it is connected to the normally open side contact to discharge. There is an advantage that the use resistor can be removed from the smoothing capacitor so as to prevent unnecessary power consumption. Also, if the power supply to the rectifier circuit is stopped, connect it to the normally closed contact and connect the smoothing capacitor in parallel with the discharge resistor,
There is an advantage that the electric charge of the smoothing capacitor can be discharged in a short time. Moreover, since the control described above can be performed with only one contact, there is an advantage that it is possible to use a smaller relay than when using a relay having two contacts.

【００３３】請求項４の発明は、負荷回路の出力電圧を
検出する電圧検出部を備え電圧検出部による検出電圧が
所定電圧に達するとオンになるスイッチング素子とブレ
ーキ抵抗との直列回路を平滑コンデンサに並列接続し、
さらに限流用抵抗にリレーの常開接点を並列接続し、ス
イッチング素子に並列にリレーの常閉接点を並列接続
し、整流回路への給電開始から所定時間が経過して負荷
回路が定常状態になると、リレーの常閉接点がオフにな
るとともに負荷回路の出力電圧の上昇によってスイッチ
ング素子もオフになるから、放電用抵抗は平滑コンデン
サから外され、無駄な電力消費が生じないという利点が
ある。しかも、整流回路への給電が停止すれば負荷回路
の出力電圧も低下するから、常閉接点がオンになるとと
もにスイッチング素子がオンになり、平滑コンデンサに
ブレーキ抵抗が並列接続されて、平滑コンデンサの電荷
の放電と回生電流の消費とがブレーキ抵抗によって行な
われるのである。ここに、放電用抵抗をブレーキ抵抗で
兼用しているから、突入電流の防止機能とブレーキ抵抗
とを備える回路構成であれば、リレーを接点構成の異な
るものに設計変更するとともに、ブレーキ抵抗に直列接
続されたスイッチング素子に対してリレーの一方の接点
（常閉接点）を並列接続するだけのごく簡単な回路変更
で、平滑コンデンサの放電に関する要求を満たすことが
できるという利点を有する。According to a fourth aspect of the present invention, a smoothing capacitor is provided which includes a voltage detecting section for detecting the output voltage of the load circuit and which turns on when a voltage detected by the voltage detecting section reaches a predetermined voltage and a brake resistor. Connected in parallel to
When the normally open contact of the relay is connected in parallel to the current limiting resistor, the normally closed contact of the relay is connected in parallel to the switching element, and when the load circuit enters a steady state after a lapse of a predetermined time from the start of power supply to the rectifier circuit. Since the normally closed contact of the relay turns off and the output voltage of the load circuit rises, the switching element also turns off, so that the discharging resistor is removed from the smoothing capacitor, and there is an advantage that unnecessary power consumption does not occur. Moreover, if the power supply to the rectifier circuit is stopped, the output voltage of the load circuit also drops, so the normally closed contact turns on, the switching element turns on, and the braking resistor is connected in parallel to the smoothing capacitor, The electric charge is discharged and the regenerative current is consumed by the brake resistor. Since the brake resistance also serves as the discharge resistance, if the circuit configuration has a function to prevent inrush current and the brake resistance, the relay design can be changed to one with a different contact configuration, and the relay can be connected in series with the brake resistance. There is an advantage that the requirement regarding the discharge of the smoothing capacitor can be satisfied by a very simple circuit modification in which one contact (normally closed contact) of the relay is connected in parallel to the connected switching element.

【図面の簡単な説明】[Brief description of drawings]

【図１】実施例１を示す回路図である。FIG. 1 is a circuit diagram showing a first embodiment.

【図２】実施利２を示す回路図である。FIG. 2 is a circuit diagram showing an implementation ratio 2.

【図３】実施例３を示す回路図である。FIG. 3 is a circuit diagram showing a third embodiment.

【図４】実施例４を示す回路図である。FIG. 4 is a circuit diagram showing a fourth embodiment.

【図５】従来例を示す回路図である。FIG. 5 is a circuit diagram showing a conventional example.

【符号の説明】[Explanation of symbols]

ａ 常開側接点 ｂ 常閉側接点 Ｃ 平滑コンデンサ ＣＮ 制御回路 ＩＮＶ 主回路 Ｍ 電動機 Ｑ トランジスタ ＲＥ 整流回路 ＲB ブレーキ抵抗 ＲD 放電用抵抗 ＲL 限流用抵抗 Ｒｙ リレー ＲｙD リレー ＲｙL リレー ｒD 接点 ｒL 接点 ｒNC 常閉接点 ｒNO 常開接点 ｒSW 双投型接点a normally open side contact b normally closed side contact C smoothing capacitor CN control circuit INV main circuit M motor Q transistor RE rectifier circuit R B Brake resistor R D discharge resistor R L limit diverted resistor Ry relay Ry D relay Ry L relay r D Contact r L contact r NC Normally closed contact r NO Normally open contact r SW Double throw contact

───────────────────────────────────────────────────── フロントページの続き (72)発明者 泉本 智昭 大阪府門真市大字門真1048番地松下電工株 式会社内 (72)発明者 水野 博史 大阪府門真市大字門真1048番地松下電工株 式会社内 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tomoaki Izumimoto 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Hiroshi Mizuno, 1048, Kadoma, Kadoma City, Osaka Matsushita Electric Co., Ltd.

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 整流回路と平滑コンデンサとの間に負荷
回路への突入電流を防止する限流用抵抗と第１のスイッ
チ要素との並列回路を挿入し、平滑コンデンサに放電用
抵抗と第２のスイッチ要素との直列回路を並列接続し、
整流回路への給電開始直後には第１のスイッチ要素をオ
フにし、給電開始から所定時間の経過後に第１のスイッ
チ要素をオンにし、給電が停止すると第２のスイッチ要
素をオンにするように第１のスイッチ要素と第２のスイ
ッチ要素とを制御する制御回路を設けたことを特徴とす
る平滑コンデンサの放電回路。1. A parallel circuit of a current limiting resistor for preventing an inrush current to a load circuit and a first switch element is inserted between the rectifying circuit and the smoothing capacitor, and the discharging resistor and the second resistor are connected to the smoothing capacitor. Connect the series circuit with the switch element in parallel,
The first switch element is turned off immediately after the start of power supply to the rectifier circuit, the first switch element is turned on after a lapse of a predetermined time from the start of power supply, and the second switch element is turned on when power supply is stopped. A discharge circuit for a smoothing capacitor, comprising a control circuit for controlling the first switch element and the second switch element. 【請求項２】 整流回路と平滑コンデンサとの間に負荷
回路への突入電流を防止する限流用抵抗とリレーの常開
接点との並列回路を挿入し、平滑コンデンサに放電用抵
抗とリレーの常閉接点との直列回路を並列接続し、整流
回路への給電開始から所定時間の経過後に常開接点をオ
ンにするとともに給電が停止するまで常開接点をオンに
保ち、給電停止後に常閉接点をオンにするようにリレー
を制御する制御回路を設けたことを特徴とする平滑コン
デンサの放電回路。2. A parallel circuit of a current limiting resistor for preventing an inrush current to the load circuit and a normally open contact of the relay is inserted between the rectifier circuit and the smoothing capacitor, and the discharging resistor and the relay normally connected to the smoothing capacitor. A series circuit with a closed contact is connected in parallel, the normally open contact is turned on after a lapse of a predetermined time from the start of power supply to the rectifier circuit, and the normally open contact is kept on until the power supply stops, and the normally closed contact after power supply is stopped. A discharge circuit for a smoothing capacitor, which is provided with a control circuit for controlling a relay so as to turn on a switch. 【請求項３】 整流回路と平滑コンデンサとの間に負荷
回路への突入電流を防止する限流用抵抗を挿入し、限流
用抵抗と平滑コンデンサの一端との接続点に共通接点を
接続した双投型接点を有するリレーの常開側接点を限流
用抵抗と整流回路との接続点に接続し、整流回路と平滑
コンデンサの他端との接続点に一端を接続した放電用抵
抗の他端にリレーの常閉側接点を接続し、整流回路への
給電開始から所定時間の経過後に共通接点を常開側接点
に接続するとともに給電が停止するまで共通接点を常開
側接点に接続し続け、給電停止後に共通接点を常閉側接
点に接続するようにリレーを制御する制御回路を設けた
ことを特徴とする平滑コンデンサの放電回路。3. A double throw in which a current limiting resistor for preventing an inrush current to the load circuit is inserted between the rectifier circuit and the smoothing capacitor, and a common contact is connected to a connection point between the current limiting resistor and one end of the smoothing capacitor. A normally open side contact of a relay having a mold contact is connected to the connection point between the current limiting resistor and the rectifier circuit, and one end is connected to the connection point between the rectifier circuit and the other end of the smoothing capacitor. Connect the normally-closed side contact, connect the common contact to the normally-open side contact after the lapse of a predetermined time from the start of power supply to the rectifier circuit, and continue to connect the common contact to the normally-open side contact until the power supply stops A discharging circuit for a smoothing capacitor, comprising a control circuit for controlling a relay so that a common contact is connected to a normally closed contact after a stop. 【請求項４】 整流回路と平滑コンデンサとの間に負荷
回路への突入電流を防止する限流用抵抗とリレーの常開
接点との並列回路を挿入し、負荷回路の出力電圧を検出
する電圧検出部による検出電圧が所定電圧に達するとオ
ンになるスイッチング素子とブレーキ抵抗との直列回路
を平滑コンデンサに並列接続し、スイッチング素子にリ
レーの常閉接点を並列接続し、整流回路への給電開始か
ら所定時間の経過後に常開接点をオンにするとともに給
電が停止するまで常開接点がオンに保ち、給電停止後に
常閉接点をオンにするようにリレーを制御する制御回路
を設けたことを特徴とする平滑コンデンサの放電回路。4. A voltage detector for detecting an output voltage of the load circuit by inserting a parallel circuit of a current limiting resistor for preventing an inrush current into the load circuit and a normally open contact of the relay between the rectifier circuit and the smoothing capacitor. A series circuit of a switching element and a brake resistor that turns on when the voltage detected by the unit reaches a predetermined voltage is connected in parallel to the smoothing capacitor, and the normally closed contact of the relay is connected in parallel to the switching element. It features a control circuit that turns on the normally open contact after a lapse of a predetermined time and keeps the normally open contact on until power supply is stopped, and controls the relay to turn on the normally closed contact after power supply is stopped. And a smoothing capacitor discharge circuit.
JP6163980A 1994-07-15 1994-07-15 Discharge circuit for smoothing capacitor Withdrawn JPH0833338A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6163980A JPH0833338A (en) 1994-07-15 1994-07-15 Discharge circuit for smoothing capacitor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6163980A JPH0833338A (en) 1994-07-15 1994-07-15 Discharge circuit for smoothing capacitor

Publications (1)

Publication Number Publication Date
JPH0833338A true JPH0833338A (en) 1996-02-02

Family

ID=15784473

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6163980A Withdrawn JPH0833338A (en) 1994-07-15 1994-07-15 Discharge circuit for smoothing capacitor

Country Status (1)

Country Link
JP (1) JPH0833338A (en)

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