JPH0454864A - Power conversion circuit - Google Patents

Power conversion circuit

Info

Publication number
JPH0454864A
JPH0454864A JP16522690A JP16522690A JPH0454864A JP H0454864 A JPH0454864 A JP H0454864A JP 16522690 A JP16522690 A JP 16522690A JP 16522690 A JP16522690 A JP 16522690A JP H0454864 A JPH0454864 A JP H0454864A
Authority
JP
Japan
Prior art keywords
transistor
load
reactor
conversion circuit
power conversion
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.)
Pending
Application number
JP16522690A
Other languages
Japanese (ja)
Inventor
Takeshi Kinoshita
剛 木下
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.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP16522690A priority Critical patent/JPH0454864A/en
Publication of JPH0454864A publication Critical patent/JPH0454864A/en
Pending legal-status Critical Current

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Abstract

PURPOSE:To suppress the rise of an output voltage when a load is abruptly reduced without using a resistor by forming an antiparallel connection of a discharge transistor to a flywheel diode to operate ON/OFF when the load is abruptly reduced. CONSTITUTION:A discharge transistor 4 has an antiparallel connection to a flywheel diode 3. If a load 7 is abruptly reduce to zero, the conduction of a transistor 2 is stopped, and the ON/OFF of the transistor 4 is simultaneously started. Energy stored in a capacitor 6 is discharged through a reactor 5 and the transistor 4. A discharge current Ic is limited by the reactor 5. Before the peak value of the current Ic reaches a rated current of the transistor 4, the transistor 4 is repeatedly turned ON, OFF. When the voltage of the capacitor 6 is lowered to a certain overvoltage level, the operation of the transistor 4 is stopped, and the transistor 2 is driven.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は降圧チョッパ方式の電力変換回路に関する。[Detailed description of the invention] [Industrial application field] The present invention relates to a step-down chopper type power conversion circuit.

〔従来の技術〕[Conventional technology]

第4図は例えば特開昭56−101223号公報に示さ
れた従来の電力変換回路を示す回路である。同図におい
て、1は直流電源、2はスイッチング素子であるトラン
ジスタTr、3はフライホイルダイオードD、5はコイ
ルし、6はコンデンサC17は負荷Zである。コイル5
とコンデンサ6はLCフィルタを構成しており、トラン
ジスタ2が出力する方形波を平滑する。
FIG. 4 shows a conventional power conversion circuit disclosed in, for example, Japanese Unexamined Patent Publication No. 56-101223. In the figure, 1 is a DC power supply, 2 is a transistor Tr which is a switching element, 3 is a flywheel diode D, 5 is a coil, and 6 is a capacitor C17, which is a load Z. coil 5
and capacitor 6 constitute an LC filter, which smoothes the square wave output from transistor 2.

この構成においては、負荷7に印加される電圧Voは、
トランジスタ2のオン・オフデユーティ比率によって決
定される。すなわち、出力電圧■oは入力電圧をV、、
スイッチング周期をT、オン時間をT。Nとすると、 となるので、デユーティ比率T。N/Tを制御すること
により出力電圧■。を所定値に制御することができる。
In this configuration, the voltage Vo applied to the load 7 is
It is determined by the on/off duty ratio of transistor 2. In other words, the output voltage ■o is the input voltage V,
The switching period is T and the on time is T. If N, then the duty ratio T. Output voltage ■ by controlling N/T. can be controlled to a predetermined value.

なお、第5図にこの回路の各部の波形を示す。Note that FIG. 5 shows waveforms at various parts of this circuit.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

この電力変換回路では、入力電圧の変動に対しでは出力
電圧を一定に制御することはできる。
This power conversion circuit can control the output voltage to be constant even when the input voltage fluctuates.

負荷7が急減して例えば零負荷になったような場合、ト
ランジスタ20オン時間を小さくして出力を絞るが、負
荷7が零に急減した場合には、エネルギーの行き先が無
いので、トランジスタ2をオフさせても、コンデンサ6
の電圧従って、出力電圧VOの上昇は避けられない。
When the load 7 suddenly decreases to, for example, zero load, the on-time of the transistor 20 is reduced to reduce the output. However, when the load 7 suddenly decreases to zero, there is no place for the energy to go, so the transistor 2 is turned on. Even if it is turned off, capacitor 6
Therefore, an increase in the output voltage VO is unavoidable.

このため、従来は、第6図に示す如く放電用抵抗10を
設けて上記出力電圧の急上昇時に、行き先の無い上記エ
ネルギーを抵抗9で消費させるか、あるいは、第7図に
示す如く放電用抵抗10とトランジスタ11を設けて、
上記出力電圧の急上昇時に、トランジスタ11をオン状
態に維持して、行き先の無い上記エネルギーを抵抗10
で消費させるようにしている。
For this reason, conventionally, a discharging resistor 10 is provided as shown in FIG. 6, and when the output voltage rises rapidly, the energy that has no destination is consumed by the resistor 9, or a discharging resistor 10 is provided as shown in FIG. 10 and a transistor 11 are provided,
When the output voltage rises rapidly, the transistor 11 is kept on and the energy with no destination is transferred to the resistor 11.
I'm trying to have it consumed.

しかし、この抵抗10でエネルギーを消費させる方法は
、抵抗10でエネルーを熱に変換して消費させるので、
抵抗が発熱し、抵抗10のために大きなスペースを必要
とするという問題があった。
However, the method of consuming energy with this resistor 10 converts energy into heat and consumes it with the resistor 10, so
There was a problem that the resistor generated heat and required a large space for the resistor 10.

この発明は上記問題を解消するためになされたもので、
抵抗を用いることなく、負荷急減時の出力電圧の上昇を
抑制とすることができる電力変換回路を提供することを
目的とする。
This invention was made to solve the above problem.
An object of the present invention is to provide a power conversion circuit that can suppress an increase in output voltage when the load suddenly decreases without using a resistor.

〔課題を解決するための手段〕[Means to solve the problem]

この発明は上記目的を達成するため、直流電源の一方極
と負荷との間に直列に挿入されたスイッチング素子とリ
アクトル、このスイッチング素子の出力端と上記直流電
源の他方極との間に挿入されたダイオード、上記負荷に
対して並列に接続され上記リアクトルとLCフィルタを
構成するコンデンサを備える電力変換回路において、上
記ダイオードと逆並列に放電用スイッチング素子を設け
、該スイッチング素子を負荷急減時に繰り返しオン・オ
フする構成とした。
In order to achieve the above object, the present invention includes a switching element and a reactor inserted in series between one pole of a DC power supply and a load, and a reactor inserted between the output end of the switching element and the other pole of the DC power supply. In a power conversion circuit comprising a diode, a capacitor connected in parallel to the load and forming the reactor and LC filter, a discharging switching element is provided antiparallel to the diode, and the switching element is repeatedly turned on when the load suddenly decreases.・Configured to turn it off.

〔作用〕[Effect]

この発明では、負荷が急減した場合に、放電用スイッチ
ング素子がオンするので、このスイッチング素子−リア
クトル−コンデンサからなる放電回路が閉成される。コ
ンデンサの放電電流はリアクトルの値で決まるレベルへ
抑制される。
In this invention, when the load suddenly decreases, the discharging switching element is turned on, so that a discharging circuit consisting of the switching element, reactor, and capacitor is closed. The discharge current of the capacitor is suppressed to a level determined by the value of the reactor.

〔実施例〕〔Example〕

以下、この発明の1実施例を図面を参照して説明する。 Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

第1図において、4は放電用のトランジスタTr1であ
って、フライホイルダイオード3に対して逆並列に接続
されている。このトランジスタ4は負荷7が急減してコ
ンデンサ6の電圧がある過電圧レベルを超えた場合に、
オン/オフ駆動を開始される。この時トランジスタ2は
その動作を停止される。他の構成は第4図のものと同じ
である。
In FIG. 1, reference numeral 4 denotes a discharge transistor Tr1, which is connected in antiparallel to the flywheel diode 3. This transistor 4 operates when the load 7 suddenly decreases and the voltage of the capacitor 6 exceeds a certain overvoltage level.
On/off driving is started. At this time, transistor 2 is stopped from operating. The other configurations are the same as those in FIG.

この構成においては、負荷7が零へ急減した場合、出力
電圧v0が急上昇するので、トランジスタ2の導通を完
全に停止し、同時に、トランジスタ4のオン/オフを開
始させる。これにより、コンデンサ6に貯えられたエネ
ルギーはリアクトル5−トランジスタ4を通して放電す
る。放電電流ICはリアクトル5で限流される。この放
電電流ICは第3図に示す波形を有するので、ピーク値
がトランジスタ4の電流定格に達する前にトランジスタ
4をオフさせ、このオン/オフ動作を繰り返させる。コ
ンデンサ6の電圧が上記ある過電圧レベルへ低下すると
、トランジスタ4のiff作を停止させ、トランジス2
を駆動する。
In this configuration, when the load 7 suddenly decreases to zero, the output voltage v0 rises rapidly, so that the conduction of the transistor 2 is completely stopped, and at the same time, the transistor 4 starts to be turned on/off. As a result, the energy stored in the capacitor 6 is discharged through the reactor 5 and the transistor 4. The discharge current IC is limited by the reactor 5. Since this discharge current IC has the waveform shown in FIG. 3, the transistor 4 is turned off before the peak value reaches the current rating of the transistor 4, and this on/off operation is repeated. When the voltage of the capacitor 6 drops to the above-mentioned certain overvoltage level, the IF operation of the transistor 4 is stopped, and the transistor 2
to drive.

上記実施例では、トランジスタ2と別体のトランジスタ
4を設けているが、第2図に示す如く、ダイオードD。
In the above embodiment, a transistor 4 separate from the transistor 2 is provided, and as shown in FIG. 2, a diode D is provided.

、Dをそれぞれを逆並列接続した2個のトランジスタ2
.4をモジュール化した、いわゆるアーム形トランジス
タモジュール9を用いれば、部品点数を減らすことがで
きる。
, D are connected in antiparallel to each other.
.. By using a so-called arm-type transistor module 9 which is a modular version of 4, the number of parts can be reduced.

〔発明の効果〕〔Effect of the invention〕

この発明は以上説明した通り、放電用トランジスタを、
フライホイルダイオードに逆並列接続して負荷急減時に
オン/オフ動作させる構成としたことにより、このオン
周期とリアクトルの限流作用で出力電圧の上昇を抑制す
ることができるので、放電用抵抗を用いなくて済む分、
従来に比し、装置を小形化することができる。
As explained above, this invention uses a discharge transistor,
By connecting the flywheel diode in antiparallel and turning it on and off when the load suddenly decreases, the output voltage rise can be suppressed by this on period and the current limiting action of the reactor, so a discharge resistor can be used. As much as you can do without it,
The device can be made more compact than before.

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

第1図および第2図はこの発明の実施例を示す回路図、
第3図は上記実施例における放電電流の波形図、第4図
は降圧チヨ・7パ方式の従来の電力変換回路の回路図、
第5図は第4図の電力変換回路の各部波形図、第6図お
よび第7図は放電用抵抗を備えた従来の電力変換回路の
回路図である。 図において、2−・トランジスタ、3−・−フライホイ
ルダイオード、4−放電用トランジスタ、5− リアク
トル、6・−コンデンサ、7−・−負荷、9−Lランジ
スタモジュール。 なお、図中、同一符号は同一または相当部分を示す。
1 and 2 are circuit diagrams showing embodiments of the present invention,
FIG. 3 is a waveform diagram of the discharge current in the above embodiment, and FIG. 4 is a circuit diagram of a conventional power conversion circuit using a step-down 7-pass voltage system.
FIG. 5 is a waveform diagram of various parts of the power conversion circuit shown in FIG. 4, and FIGS. 6 and 7 are circuit diagrams of a conventional power conversion circuit equipped with a discharge resistor. In the figure, 2--transistor, 3--flywheel diode, 4--discharge transistor, 5--reactor, 6--capacitor, 7--load, 9--L transistor module. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

【特許請求の範囲】[Claims] 直流電源の一方極と負荷との間に直列に挿入されたスイ
ッチング素子とリアクトル、このスイッチング素子の出
力端と上記直流電源の他方極との間に挿入されたダイオ
ード、上記負荷に対して並列に接続され上記リアクトル
とLCフィルタを構成するコンデンサを備える電力変換
回路において、上記ダイオードと逆並列に放電用スイッ
チング素子が設けられ、該スイッチング素子は負荷急減
時に繰り返しオン/オフされることを特徴とする電力変
換回路。
A switching element and a reactor inserted in series between one pole of the DC power supply and the load, a diode inserted between the output terminal of this switching element and the other pole of the DC power supply, and a diode in parallel with the load. A power conversion circuit comprising a capacitor connected to the reactor and forming an LC filter, characterized in that a discharging switching element is provided antiparallel to the diode, and the switching element is repeatedly turned on and off when the load suddenly decreases. Power conversion circuit.
JP16522690A 1990-06-21 1990-06-21 Power conversion circuit Pending JPH0454864A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16522690A JPH0454864A (en) 1990-06-21 1990-06-21 Power conversion circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16522690A JPH0454864A (en) 1990-06-21 1990-06-21 Power conversion circuit

Publications (1)

Publication Number Publication Date
JPH0454864A true JPH0454864A (en) 1992-02-21

Family

ID=15808258

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16522690A Pending JPH0454864A (en) 1990-06-21 1990-06-21 Power conversion circuit

Country Status (1)

Country Link
JP (1) JPH0454864A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0987806A2 (en) * 1998-09-16 2000-03-22 Siemens Aktiengesellschaft Excess voltage switch-off circuit
US6911806B2 (en) 1995-11-28 2005-06-28 Fujitsu Limited DC to DC converter producing output voltage exhibiting rise and fall characteristics independent of load thereon
JP6011737B1 (en) * 2016-03-14 2016-10-19 富士電機株式会社 Step-down chopper circuit
JP6011736B1 (en) * 2016-03-14 2016-10-19 富士電機株式会社 Boost chopper circuit
CN107919824A (en) * 2017-12-24 2018-04-17 佛山中锦微电科技有限公司 A kind of self-absorption formula throw load overvoltage crowbar and voltage regulator of prescribing a time limit

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6911806B2 (en) 1995-11-28 2005-06-28 Fujitsu Limited DC to DC converter producing output voltage exhibiting rise and fall characteristics independent of load thereon
US7129682B2 (en) 1995-11-28 2006-10-31 Fujitsu Limited DC to DC converter producing output voltage exhibit rise and fall characteristics independent of load thereon
EP0987806A2 (en) * 1998-09-16 2000-03-22 Siemens Aktiengesellschaft Excess voltage switch-off circuit
EP0987806A3 (en) * 1998-09-16 2000-11-29 Siemens Aktiengesellschaft Excess voltage switch-off circuit
JP6011737B1 (en) * 2016-03-14 2016-10-19 富士電機株式会社 Step-down chopper circuit
JP6011736B1 (en) * 2016-03-14 2016-10-19 富士電機株式会社 Boost chopper circuit
US10164530B2 (en) 2016-03-14 2018-12-25 Fuji Electric Co., Ltd. Boost chopper circuit including switching device circuit and backflow prevention diode circuit
US10256721B2 (en) 2016-03-14 2019-04-09 Fuji Electric Co., Ltd. Step-down chopper circuit including a switching device circuit and a backflow prevention diode circuit
CN107919824A (en) * 2017-12-24 2018-04-17 佛山中锦微电科技有限公司 A kind of self-absorption formula throw load overvoltage crowbar and voltage regulator of prescribing a time limit

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