JPH07170759A - Detecting method of short circuit of bridge circuit in power converter - Google Patents
Detecting method of short circuit of bridge circuit in power converterInfo
- Publication number
- JPH07170759A JPH07170759A JP5341939A JP34193993A JPH07170759A JP H07170759 A JPH07170759 A JP H07170759A JP 5341939 A JP5341939 A JP 5341939A JP 34193993 A JP34193993 A JP 34193993A JP H07170759 A JPH07170759 A JP H07170759A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- voltage
- short
- bridge circuit
- short circuit
- 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
Links
Landscapes
- Inverter Devices (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、電力変換装置を構成す
るインバータやコンバータ等におけるブリッジ回路の短
絡検出方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a short circuit in a bridge circuit in an inverter, a converter or the like which constitutes a power converter.
【0002】[0002]
【従来の技術】半導体スイッチング素子によって構成し
たブリッジ回路における上下アームの短絡は図3に示す
方法によって検出されていた。図3において、直流電源
101の両端に並列接続したコンデンサ102のマイナ
ス側端子と、直列接続した2つの半導体スイッチング素
子104と105より成るブリッジ回路における半導体
スイッチング素子105のエミッタ端子との間にダイオ
ード107を挿入しておき、ダイオード107と並列に
抵抗106と直列接続したホールCT103より成る回
路を設けた。半導体スイッチング素子104と105が
同時にオンとなるときは上下アーム間の短絡事故の発生
となるので、短絡電流が直流電源101から供給され
る。この短絡電流をホールCT103によって検出し、
このホールCT103を介して変換された検出電圧を比
較回路109において基準電圧108と比較することに
よって短絡事故発生を検出する。比較回路109からの
検出信号を遮断回路110に入力させ、半導体スイッチ
ング素子104と105をオン・オフ制御するゲート駆
動回路111から出力する駆動信号を遮断回路110か
らの指令信号により半導体スイッチング素子104,1
05を同時に、もしくはいずれか一方を遮断するように
していた。2. Description of the Related Art A short circuit between upper and lower arms in a bridge circuit composed of semiconductor switching elements has been detected by the method shown in FIG. In FIG. 3, a diode 107 is provided between a negative terminal of a capacitor 102 connected in parallel to both ends of a DC power supply 101 and an emitter terminal of a semiconductor switching element 105 in a bridge circuit composed of two semiconductor switching elements 104 and 105 connected in series. Is inserted in advance, and a circuit including the Hall CT 103 connected in series with the resistor 106 in parallel with the diode 107 is provided. When the semiconductor switching elements 104 and 105 are turned on at the same time, a short-circuit accident occurs between the upper and lower arms, so that a short-circuit current is supplied from the DC power supply 101. This short circuit current is detected by Hall CT103,
The detection voltage converted through the hole CT 103 is compared with the reference voltage 108 in the comparison circuit 109 to detect the occurrence of a short circuit accident. The detection signal from the comparison circuit 109 is input to the cutoff circuit 110, and the drive signal output from the gate drive circuit 111 that controls ON / OFF of the semiconductor switching elements 104 and 105 is output by the command signal from the cutoff circuit 110 to the semiconductor switching element 104, 1
05 was blocked at the same time or one of them was blocked.
【0003】[0003]
【発明が解決しようとする課題】上述したホールCTを
挿入した短絡電流の検出方法では、検出回路を構成する
ホールCT103,抵抗106,ダイオード107およ
びこれら構成要素を接続する配線等によって電源インピ
ーダンスが大きくなり、半導体スイッチング素子のスナ
バ損失も大きくなる。また、インバータ入力部では静電
ノイズが発生し易いが、ホールCT103は静電ノイズ
に弱い欠点がある。従って、インバータを構成するブリ
ッジ回路の短絡電流検出にホールCTを使用することは
適当ではない。短絡電流を検出する手段としてはコンデ
ンサの放電電流を交流CTによって検出する方法もある
が、検出回路の構成が複雑になる欠点があった。本発明
は上述した従来技術の欠点を解消するためになされたも
のであって、ブリッジ回路のアームにおける両端電圧を
検出し、両端電圧の落ち込みを基準値と比較することに
よって短絡を検出する方法を提案しようとするものであ
る。In the above-described method for detecting a short-circuit current in which the hole CT is inserted, the power source impedance is large due to the hole CT 103, the resistor 106, the diode 107, and the wiring connecting these components, which constitute the detection circuit. Therefore, the snubber loss of the semiconductor switching element also increases. Further, although electrostatic noise is likely to occur in the inverter input section, the Hall CT 103 has a drawback that it is weak against electrostatic noise. Therefore, it is not appropriate to use the Hall CT for detecting the short circuit current of the bridge circuit which constitutes the inverter. As a means for detecting the short-circuit current, there is a method of detecting the discharge current of the capacitor by AC CT, but there is a drawback that the configuration of the detection circuit becomes complicated. The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and provides a method for detecting a short circuit voltage by detecting the voltage across the arm of a bridge circuit and comparing the voltage drop across the arm with a reference value. It is a proposal.
【0004】[0004]
【課題を解決するための手段】上述した目的を達成する
ために、本発明に係る電力変換回路におけるブリッジ回
路の短絡検出方法は、ブリッジ回路のアームにおける両
端電圧を検出し、短絡に起因する両端電圧の落ち込み量
を基準電圧と比較することにより短絡を検出するもので
ある。In order to achieve the above-mentioned object, a method of detecting a short circuit of a bridge circuit in a power conversion circuit according to the present invention detects a voltage at both ends of an arm of the bridge circuit and detects both ends due to the short circuit. A short circuit is detected by comparing the amount of voltage drop with a reference voltage.
【0005】[0005]
【作用】ブリッジ回路のアーム両端の電圧を検出する
と、アーム短絡の場合には0.5EDC(EDCは直流電源
電圧)以上も落ち込むので基準電圧と比較することによ
って短絡を検出できる。When the voltage across the arms of the bridge circuit is detected, the voltage drops by 0.5E DC (E DC is the DC power supply voltage) or more in the case of an arm short circuit, so that the short circuit can be detected by comparing with the reference voltage.
【0006】[0006]
【実施例】以下、本発明の実施例を図面を参照しながら
説明する。図1は本発明による実施例を示すブロック図
であり、直流電源1の両端にはコンデンサ2と2つの半
導体スイッチング素子4と5を直列接続して構成したブ
リッジ回路が並列接続してあり、このブリッジ回路にお
ける両端電圧を検出回路14で検出する。短絡電流が流
れたときにおける並列コンデンサ2の両端電圧の落ち込
みは、図2(a)に示すように直流電源電圧をEDCとす
ると0.1EDC程度であるが、ブリッジ回路のアームに
おける両端電圧の落ち込みは、配線のインダクタンスが
70nHと小さくても0.5EDC位であり、配線のイン
ダクタンスが70nH以上になると0.5EDC以上とな
り、図2(b)に示す通りである。即ち、配線のインダ
クタンスが大きくても短絡発生時におけるアームの両端
電圧の落ち込みは0.5EDCは見込まれるので短絡を検
出することは容易であり、比較回路9と遮断回路10を
介してゲート駆動回路11の駆動信号を遮断する。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment according to the present invention, in which a DC power supply 1 is connected at both ends thereof in parallel with a bridge circuit constituted by connecting a capacitor 2 and two semiconductor switching elements 4 and 5 in series. The voltage across the bridge circuit is detected by the detection circuit 14. The drop of the voltage across the parallel capacitor 2 when a short-circuit current flows is about 0.1E DC when the DC power supply voltage is E DC as shown in FIG. 2A, but the voltage across the arm of the bridge circuit is 2E is about 0.5E DC even when the wiring inductance is as small as 70 nH, and becomes 0.5E DC or more when the wiring inductance is 70 nH or more, as shown in FIG. 2B. That is, even if the inductance of the wiring is large, the voltage drop across the arm is expected to be 0.5E DC when a short circuit occurs, so it is easy to detect a short circuit, and the gate drive is performed via the comparison circuit 9 and the cutoff circuit 10. The drive signal of the circuit 11 is cut off.
【0007】次に、短絡検出回路と半導体スイッチング
素子の遮断回路の細部について説明する。図1におい
て、ブリッジ回路のアームにおける両端電圧は検出回路
14を介して比較回路9に入力すると共に、平均値電圧
検出回路13と電圧分周回路8を介して比較回路9に入
力する。直流電源電圧EDCは平均値電圧検出回路13に
おいて平均化され、さらに電圧分周回路8において分周
されて比較回路9の基準電圧となる。例えば、電圧分周
回路8において1/2分周とすると直流電源電圧EDCの
1/2の電圧が基準値となるので、ブリッジ回路に短絡
電流が流れたときのブリッジ回路のアームにおける両端
電圧が0.5EDC以下になると短絡発生が検出される。
なお、電圧分周回路8の分周比は回路特性に対応して調
整し、短絡発生を適確に検出できるようにする。Next, details of the short circuit detection circuit and the cutoff circuit of the semiconductor switching element will be described. In FIG. 1, the voltage across the arms of the bridge circuit is input to the comparison circuit 9 via the detection circuit 14 and to the comparison circuit 9 via the average value voltage detection circuit 13 and the voltage divider circuit 8. The DC power supply voltage E DC is averaged by the average value voltage detection circuit 13, and further divided by the voltage division circuit 8 to become the reference voltage of the comparison circuit 9. For example, if the voltage divider circuit 8 is divided by 1/2, the voltage of 1/2 of the DC power supply voltage E DC becomes the reference value, so that the voltage across the arms of the bridge circuit when a short-circuit current flows When is less than 0.5E DC, the occurrence of short circuit is detected.
The frequency division ratio of the voltage divider circuit 8 is adjusted according to the circuit characteristics so that the occurrence of short circuit can be detected accurately.
【0008】比較回路9において短絡発生が検出される
と、比較回路9から遮断回路10への出力信号によりゲ
ート駆動回路11から半導体スイッチング素子5への駆
動信号は遮断回路10によって遮断され、半導体スイッ
チング素子5はオフとなる。なお、半導体スイッチング
素子4は遮断回路10を介することなくゲート駆動回路
11によってオン・オフ制御されるように構成してあ
る。When a short circuit is detected in the comparison circuit 9, the drive signal from the gate drive circuit 11 to the semiconductor switching element 5 is cut off by the cutoff circuit 10 by the output signal from the comparison circuit 9 to the cutoff circuit 10, and semiconductor switching is performed. The element 5 is turned off. The semiconductor switching element 4 is configured to be on / off controlled by the gate drive circuit 11 without the interruption circuit 10.
【0009】[0009]
【発明の効果】以上説明したように、本発明に係る電力
変換装置におけるブリッジ回路の短絡検出方法は、ブリ
ッジ回路のアームにおける両端電圧を検出し、この検出
電圧の落ち込み量によって短絡の発生を検出するもので
ある。従って、ホールCTによる短絡検出方法よりも検
出装置の寸法は小さくなり、配線のインダクタンスを小
さくできるのでスナバ損失も小さくなる。また、ホール
CTのように静電ノイズによるトラブルも発生せず経済
的に優れた変換損失の少ない短絡電流の検出方法を実現
できる。As described above, the method for detecting a short circuit in the bridge circuit in the power converter according to the present invention detects the voltage across the arms of the bridge circuit and detects the occurrence of a short circuit by the amount of drop in the detected voltage. To do. Therefore, the size of the detection device is smaller than that of the short-circuit detection method using the Hall CT, and the inductance of the wiring can be reduced, so snubber loss is also reduced. Further, unlike the Hall CT, troubles due to electrostatic noise do not occur, and an economically excellent short-circuit current detection method with less conversion loss can be realized.
【図1】本発明による短絡検出方法の実施例を示すブロ
ック図。FIG. 1 is a block diagram showing an embodiment of a short circuit detection method according to the present invention.
【図2】短絡発生時における電圧波形図。FIG. 2 is a voltage waveform diagram when a short circuit occurs.
【図3】従来の短絡検出方法を示すブロック図。FIG. 3 is a block diagram showing a conventional short circuit detection method.
1 直流電源 2 コンデンサ 4,5 半導体スイッチング素子 8 電圧分周回路 9 比較回路 10 遮断回路 11 ゲート駆動回路 13 平均値電圧検出回路 14 検出回路 DESCRIPTION OF SYMBOLS 1 DC power supply 2 Capacitors 4, 5 Semiconductor switching element 8 Voltage divider circuit 9 Comparison circuit 10 Breaking circuit 11 Gate drive circuit 13 Average value voltage detection circuit 14 Detection circuit
Claims (1)
素子より成る電力変換装置におけるブリッジ回路におい
て、 前記ブリッジ回路のアームを構成する2つの半導体スイ
ッチング素子の両端電圧を検出して比較回路に入力さ
せ、この比較回路において前記両端電圧の落ち込み量と
基準電圧を比較することにより前記ブリッジ回路におけ
る短絡を検出することを特徴とする電力変換装置におけ
るブリッジ回路の短絡検出方法。1. A bridge circuit in a power conversion device comprising two semiconductor switching elements connected in series, wherein the voltages across the two semiconductor switching elements forming the arm of the bridge circuit are detected and input to a comparison circuit. A short circuit detection method for a bridge circuit in a power conversion device, comprising detecting a short circuit in the bridge circuit by comparing a drop amount of the voltage across both ends with a reference voltage in a comparison circuit.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5341939A JPH07170759A (en) | 1993-12-13 | 1993-12-13 | Detecting method of short circuit of bridge circuit in power converter |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5341939A JPH07170759A (en) | 1993-12-13 | 1993-12-13 | Detecting method of short circuit of bridge circuit in power converter |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH07170759A true JPH07170759A (en) | 1995-07-04 |
Family
ID=18349935
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP5341939A Pending JPH07170759A (en) | 1993-12-13 | 1993-12-13 | Detecting method of short circuit of bridge circuit in power converter |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH07170759A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2939577A1 (en) * | 2008-12-10 | 2010-06-11 | Mitsubishi Electric Corp | ENERGY CONVERSION DEVICE |
-
1993
- 1993-12-13 JP JP5341939A patent/JPH07170759A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2939577A1 (en) * | 2008-12-10 | 2010-06-11 | Mitsubishi Electric Corp | ENERGY CONVERSION DEVICE |
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