JPH0556553A - Igbt gate drive circuit - Google Patents

Igbt gate drive circuit

Info

Publication number
JPH0556553A
JPH0556553A JP3232173A JP23217391A JPH0556553A JP H0556553 A JPH0556553 A JP H0556553A JP 3232173 A JP3232173 A JP 3232173A JP 23217391 A JP23217391 A JP 23217391A JP H0556553 A JPH0556553 A JP H0556553A
Authority
JP
Japan
Prior art keywords
igbt
gate
drive circuit
temperature
gate drive
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
JP3232173A
Other languages
Japanese (ja)
Inventor
Motosumi Yura
元澄 由良
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.)
Okuma Corp
Original Assignee
Okuma Machinery 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 Okuma Machinery Works Ltd filed Critical Okuma Machinery Works Ltd
Priority to JP3232173A priority Critical patent/JPH0556553A/en
Publication of JPH0556553A publication Critical patent/JPH0556553A/en
Pending legal-status Critical Current

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  • Protection Of Static Devices (AREA)
  • Power Conversion In General (AREA)
  • Inverter Devices (AREA)

Abstract

PURPOSE:To obtain an IGBT gate drive circuit capable of protecting a semiconductor (IGBT) chip from overheating in any loaded condition by detecting the temperatures of such a chip directly and on real time. CONSTITUTION:A given a.c. voltage is applied by an oscillator 12 across the terminals of the gate and emitter of an IGBT 5. An a.c. electric current flows in response to the static capacitance Ciss. Since the static capacitance Ciss has a temperature correlativity, the static capacitance Ciss is detected by the use of the detected value of the a.c. electric current obtainable by a static capacitance detecting circuit 13 arranged between the oscillator 12 and a transformer 11. Then, the output of the static capacitance detecting circuit 13, i.e., the detected value of the static capacitance, is compared by a comparator 18 with a reference voltage 19. If the temperature of the IGBT 5 is beyond an allowable temperature, the output of the comparator is inverted to represent an abnormal state. A step is taken to suspend the operation of an invertor and others to perform a protection from overheating. Thus, a reliable protection is possible in any loaded condition.

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、インバータなどの電力
変換器を構成する半導体素子(IGBT)の過負荷等に
よる温度上昇に対する保護を図ったIGBTのゲートド
ライブ回路に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate drive circuit for an IGBT, which protects a semiconductor element (IGBT) that constitutes a power converter such as an inverter from temperature rise due to overloading.

【0002】[0002]

【従来の技術】インバータ等において、トランジスタ、
IGBT等の半導体素子2は一般的に図4のように冷却
フィン1に実装される。インバータの負荷が増大し、半
導体素子2の発生損失が増大すると冷却フィン1の温度
が上昇するため、半導体素子2の内部温度が許容限界を
超えて破壊に至る可能性があり、このような事態を避け
るため、従来は温度センサ3を冷却フィン1上に実装し
て温度検出を行っている。即ち冷却フィン1の温度が所
定値を超えた場合には、過熱状態としてインバータの停
止等の異常処理を行ない、半導体素子2の破壊を未然に
防止している。また、図5に従来の一般的なIGBTの
ゲートドライブ回路例を示す。図中、5はIGBTであ
り、入力信号4に応じてIGBT5をON/OFFさせ
ることがこのゲートドライブ回路の目的である。この図
から明らかなように、従来IGBTのゲートドライブ回
路は、単に入力信号4を増幅器6によって増幅している
だけであって、IGBT5の温度の状態は全然考慮して
いない。
2. Description of the Related Art In inverters, transistors,
A semiconductor element 2 such as an IGBT is generally mounted on the cooling fin 1 as shown in FIG. When the load of the inverter increases and the generated loss of the semiconductor element 2 increases, the temperature of the cooling fin 1 rises, so that the internal temperature of the semiconductor element 2 may exceed the allowable limit and may be destroyed. In order to avoid this, conventionally, the temperature sensor 3 is mounted on the cooling fin 1 to detect the temperature. That is, when the temperature of the cooling fins 1 exceeds a predetermined value, the semiconductor device 2 is prevented from being destroyed by performing an abnormal process such as stopping the inverter in an overheated state. FIG. 5 shows an example of a conventional general IGBT gate drive circuit. In the figure, 5 is an IGBT, and the purpose of this gate drive circuit is to turn on / off the IGBT 5 according to the input signal 4. As is apparent from this figure, the conventional IGBT gate drive circuit merely amplifies the input signal 4 by the amplifier 6, and does not consider the temperature state of the IGBT 5 at all.

【0003】[0003]

【発明が解決しようとする課題】上述の従来技術におい
ては保護すべき半導体素子の温度は計測せず、その代わ
りとして冷却フィンの温度を計測しているため、保護機
能が不完全であった。つまり、半導体素子の内部温度と
冷却フィンの温度との間には温度差が生じており、特に
数秒以下の短時間における過負荷時には、冷却フィンの
温度が緩慢にしか変化しないにも関わらず半導体素子の
内部温度が急激に上昇し、破壊に至る場合があった。本
発明は上述のような事情からなされたものであり、本発
明の目的は、インバータ装置において半導体素子(IG
BT)のチップの温度を直接的にリアルタイムで検出
し、いかなる負荷状態においても過熱から確実に保護す
るIBGTのゲートドライブ回路を提供することにあ
る。
In the above-mentioned conventional technique, the temperature of the semiconductor element to be protected is not measured, but the temperature of the cooling fin is measured instead, so that the protection function is incomplete. That is, there is a temperature difference between the internal temperature of the semiconductor element and the temperature of the cooling fin, and the semiconductor temperature of the cooling fin changes only slowly even when overloaded in a short time of several seconds or less. In some cases, the internal temperature of the device suddenly rose and the device was destroyed. The present invention has been made under the circumstances as described above, and an object of the present invention is to provide a semiconductor element (IG) in an inverter device.
An object of the present invention is to provide an IBGT gate drive circuit that directly detects the temperature of a BT) chip in real time and reliably protects it from overheating under any load condition.

【0004】[0004]

【課題を解決するための手段】本発明は、ON/OFF
を指令する入力信号に応じてIGBTのゲート端子に電
圧を印加することによって前記IGBTをON/OFF
させるIGBTのゲートドライブ回路に関するもので、
本発明の上記目的は、前記IGBTのゲート・エミッタ
端子間に所定の交流電圧を印加する信号発生部と、前記
交流電圧によって前記IGBTのゲート端子に流れる電
流に基づいて前記ゲート・エミッタ端子間の静電容量を
検知する検知手段と、前記静電容量が所定値を超えて変
化した場合に異常状態として外部に出力する異常信号出
力部とを設けることによって達成される。
The present invention is an ON / OFF
ON / OFF of the IGBT by applying a voltage to the gate terminal of the IGBT according to an input signal instructing
It relates to the gate drive circuit of the IGBT to be
The above object of the present invention is to provide a signal generator that applies a predetermined AC voltage between the gate and emitter terminals of the IGBT, and between the gate and emitter terminals based on a current flowing through the gate terminal of the IGBT by the AC voltage. This is achieved by providing a detection unit that detects the electrostatic capacity and an abnormal signal output unit that outputs an abnormal state to the outside when the electrostatic capacity changes beyond a predetermined value.

【0005】[0005]

【作用】IGBTのゲート・エミッタ端子間に所定の交
流電圧を印加する信号発生部と、前記交流電圧によって
前記IGBTのゲート端子に流れる電流に基づいてゲー
ト・エミッタ端子間の静電容量を検知する検知手段の働
きによって、動作中のIGBTの静電容量の変化を計測
することが出来る。IGBTのゲート・エミッタ端子間
の静電容量Cissは、温度に対して図3に示すような
相関関係を持っているため、静電容量Cissを検出す
ることによって、等価的にIGBTのチップの温度を計
測することができる。
A signal generator for applying a predetermined AC voltage between the gate and emitter terminals of the IGBT, and a capacitance between the gate and emitter terminals is detected based on a current flowing through the gate terminal of the IGBT by the AC voltage. The change of the electrostatic capacitance of the operating IGBT can be measured by the function of the detecting means. Since the electrostatic capacitance Ciss between the gate and emitter terminals of the IGBT has a correlation as shown in FIG. 3 with respect to the temperature, by detecting the electrostatic capacitance Ciss, the temperature of the IGBT chip is equivalently measured. Can be measured.

【0006】[0006]

【実施例】図1に、本発明によるIGBTのゲートドラ
イブ回路の実施例を示す。図中、増幅器6、トランジス
タ7A及び7B、抵抗8によって構成される起動回路
は、従来技術によるゲートドライブ回路と全く等価であ
り、説明は省略する。IGBT5のゲート・エミッタ端
子には、コンデンサ9、インダクタ10及びトランス1
1を介して発振器12が接続されていて、その発振周波
数はコンデンサ9、インダクタ10及びIGBT5のゲ
ート・エミッタ端子間の静電容量Cissによって決ま
る共振周波数の近傍に設定されている。なお、実際には
発振周波数は数MHz程度に設定される。このような回
路によって、IGBT5のゲート・エミッタ端子間には
発振器12による所定の交流電圧が印加され、その静電
容量Cissに応じて交流電流が流れるが、前述したよ
うに静電容量Cissには温度相関性があることから、
この交流電流はIGBT5のチップの温度によってその
振幅、位相が変化する。そのため、発振器12とトラン
ス11の間に静電容量検出回路13を設け、前記交流電
流の検出値から静電容量Cissを検出するようにして
いる。
1 shows an embodiment of an IGBT gate drive circuit according to the present invention. In the figure, the starting circuit constituted by the amplifier 6, the transistors 7A and 7B, and the resistor 8 is completely equivalent to the gate drive circuit according to the conventional technique, and the description thereof is omitted. At the gate / emitter terminal of the IGBT 5, a capacitor 9, an inductor 10 and a transformer 1 are provided.
An oscillator 12 is connected via 1 and its oscillation frequency is set near the resonance frequency determined by the capacitance Ciss between the capacitor 9, the inductor 10 and the gate / emitter terminal of the IGBT 5. Note that the oscillation frequency is actually set to about several MHz. With such a circuit, a predetermined AC voltage is applied between the gate and emitter terminals of the IGBT 5 by the oscillator 12 and an AC current flows according to the electrostatic capacitance Ciss thereof. Since there is a temperature correlation,
The amplitude and phase of this alternating current change depending on the temperature of the chip of the IGBT 5. Therefore, the electrostatic capacitance detection circuit 13 is provided between the oscillator 12 and the transformer 11, and the electrostatic capacitance Ciss is detected from the detected value of the alternating current.

【0007】なお、静電容量検出回路13の内部回路の
一実施例を図2に示す。この図2の回路例は、出来る限
り簡単な構成で機能を実現するべく考案された例であ
り、前記交流電流の振幅のみを検出するものである。ダ
イオード14A〜14Dは高速でかつ電圧降下の少ない
ショットキーダイオードを使用し、交流電流を全波整流
している。そして、抵抗器15によって電流を電圧に変
換し、更にコンデンサ16によって平滑することによっ
て、IGBT5のゲート・エミッタ間の静電容量Cis
sを表わす直流電圧信号(以下、これを静電容量検出値
と呼ぶ)を得ている。ここで、トランジスタ17の機能
について説明する。これまで述べてきたような静電容量
の検出方法は、IGBT5のスイッチング時の過渡状態
中には正しい検出を行なうことができないため、このよ
うな期間中にはトランジスタ17をONさせて出力信号
を短絡することによって検出値を無視できるようになっ
ている。
An embodiment of the internal circuit of the capacitance detecting circuit 13 is shown in FIG. The circuit example of FIG. 2 is an example devised to realize a function with a configuration as simple as possible, and detects only the amplitude of the alternating current. The diodes 14A to 14D are Schottky diodes that are fast and have a small voltage drop, and full-wave rectify the alternating current. Then, by converting the current into a voltage by the resistor 15 and smoothing it by the capacitor 16, the electrostatic capacitance Cis between the gate and the emitter of the IGBT 5 is obtained.
A DC voltage signal representing s (hereinafter referred to as capacitance detection value) is obtained. Here, the function of the transistor 17 will be described. Since the electrostatic capacitance detection method as described above cannot perform correct detection during the transient state at the time of switching the IGBT 5, the transistor 17 is turned on during such a period to output the output signal. The detection value can be ignored by short-circuiting.

【0008】さて再び図1の説明に戻ると、静電容量検
出回路13の出力、つまり静電容量検出値はコンパレー
タ18に入力されており、コンパレータ18で基準電圧
19と比較される。基準電圧19はIGBT5が許容温
度に達したときの静電容量検出値に等しい値に予め設定
されているため、もしIGBT5の温度が許容温度を超
えた場合にはコンパレータ18の出力が反転し、異常状
態として出力される。そこで、この出力信号に応じてイ
ンバータの運転停止等の処理を行うことができる。
Returning to the description of FIG. 1, the output of the electrostatic capacitance detection circuit 13, that is, the electrostatic capacitance detection value is input to the comparator 18, and is compared with the reference voltage 19 by the comparator 18. Since the reference voltage 19 is preset to a value equal to the capacitance detection value when the IGBT 5 reaches the allowable temperature, if the temperature of the IGBT 5 exceeds the allowable temperature, the output of the comparator 18 is inverted, It is output as an abnormal condition. Therefore, processing such as operation stop of the inverter can be performed according to the output signal.

【0009】なお、ここでコンデンサ9とインダクタ1
0による共振回路について言及する。図1の回路におい
て、トランジスタ7A、7B及び抵抗器8による駆動回
路の出力部はトランス11とIGBT5に並列に接続さ
れていることから、駆動回路の出力信号がトランス11
に流入しないように電気的に分離する必要がある。そこ
で、トランス11側に発振器12の周波数に合せた直列
共振回路を設け、交流信号以外の電流成分が流れないよ
うにしている。
Here, the capacitor 9 and the inductor 1
Reference is made to a resonant circuit with zero. In the circuit of FIG. 1, since the output portion of the drive circuit including the transistors 7A and 7B and the resistor 8 is connected in parallel to the transformer 11 and the IGBT 5, the output signal of the drive circuit is the output signal of the transformer 11.
Need to be electrically separated so that it does not flow into the. Therefore, a series resonance circuit matching the frequency of the oscillator 12 is provided on the transformer 11 side so that current components other than the AC signal do not flow.

【0010】以上、本発明の実施例をIGBTを対象に
説明したが、本発明の原理は、IGBTと全く同等のゲ
ート構造を持つMOSFETに対してもそのまま使用す
ることが出来る。
Although the embodiments of the present invention have been described above for the IGBT, the principle of the present invention can be used as it is for a MOSFET having a gate structure exactly equivalent to that of the IGBT.

【0011】[0011]

【発明の効果】本発明によれば、IGBTを使用したイ
ンバータ装置において、IGBTのチップの温度を直接
的にかつリアルタイムで検出し、過熱から保護できるた
め、いかなる負荷状態においても確実に保護することが
可能である。
According to the present invention, in an inverter device using an IGBT, the temperature of the IGBT chip can be detected directly and in real time and can be protected from overheating, so that it can be reliably protected under any load condition. Is possible.

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

【図1】本発明によるIGBTのゲートドライブ回路の
一実施例である。
FIG. 1 is an embodiment of a gate drive circuit for an IGBT according to the present invention.

【図2】静電容量検出回路の一実施例を示す回路図であ
る。
FIG. 2 is a circuit diagram showing an embodiment of a capacitance detection circuit.

【図3】IGBTの静電容量Cissの温度に対する相
関を示すグラフである。
FIG. 3 is a graph showing the correlation of the capacitance Ciss of the IGBT with respect to temperature.

【図4】従来技術によるインバータの過熱保護方式を説
明するための図である。
FIG. 4 is a diagram for explaining an inverter overheat protection method according to a conventional technique.

【図5】従来の一般的なゲートドライブ回路である。FIG. 5 is a conventional general gate drive circuit.

【符号の説明】[Explanation of symbols]

1 冷却フイン 2 半導体素子 3 温度センサ 5 IGBT 10 インダクタ 11 トランス 12 発振器 13 静電容量検出回路 1 Cooling fin 2 Semiconductor element 3 Temperature sensor 5 IGBT 10 Inductor 11 Transformer 12 Oscillator 13 Capacitance detection circuit

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 ON/OFFを指令する入力信号に応じ
てIGBTのゲート端子に電圧を印加することによって
前記IGBTをON/OFFさせるIGBTのゲートド
ライブ回路において、前記IGBTのゲート・エミッタ
端子間に所定の交流電圧を印加する信号発生部と、前記
交流電圧によって前記IGBTのゲート端子に流れる電
流に基づいて前記ゲート・エミッタ端子間の静電容量を
検知する検知手段と、前記静電容量が所定値を超えて変
化した場合に異常状態として外部に出力する異常信号出
力部とを備えたことを特徴とするIGBTのゲートドラ
イブ回路。
1. In an IGBT gate drive circuit for turning on / off the IGBT by applying a voltage to the gate terminal of the IGBT according to an input signal for instructing ON / OFF, between the gate and emitter terminals of the IGBT. A signal generator that applies a predetermined AC voltage, a detection unit that detects the electrostatic capacitance between the gate and emitter terminals based on the current that flows through the gate terminal of the IGBT by the AC voltage, and the electrostatic capacitance is predetermined. An IGBT gate drive circuit, comprising: an abnormal signal output unit that outputs an abnormal state to the outside when the change exceeds a value.
【請求項2】 前記信号発生部は所定のインダクタンス
を介して前記IGBTのゲート端子に接続され、前記ゲ
ート・エミッタ端子間の静電容量と前記インダクタンス
によって共振回路が構成されている請求項1に記載のI
GBTのゲートドライブ回路。
2. The signal generating section is connected to a gate terminal of the IGBT via a predetermined inductance, and a resonance circuit is formed by the capacitance between the gate and emitter terminals and the inductance. I described
Gate drive circuit of GBT.
【請求項3】 前記異常信号出力部には前記ON/OF
Fを指令する入力信号が入力され、前記IGBTがスイ
ッチングの過渡期間である時には異常信号を外部に出力
しないようにした請求項2に記載のIGBTのゲートド
ライブ回路。
3. The ON / OF is provided in the abnormal signal output section.
3. The gate drive circuit for an IGBT according to claim 2, wherein an input signal for instructing F is input, and an abnormal signal is not output to the outside when the IGBT is in a transitional period of switching.
JP3232173A 1991-08-20 1991-08-20 Igbt gate drive circuit Pending JPH0556553A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3232173A JPH0556553A (en) 1991-08-20 1991-08-20 Igbt gate drive circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3232173A JPH0556553A (en) 1991-08-20 1991-08-20 Igbt gate drive circuit

Publications (1)

Publication Number Publication Date
JPH0556553A true JPH0556553A (en) 1993-03-05

Family

ID=16935150

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3232173A Pending JPH0556553A (en) 1991-08-20 1991-08-20 Igbt gate drive circuit

Country Status (1)

Country Link
JP (1) JPH0556553A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06209519A (en) * 1993-01-08 1994-07-26 Honda Motor Co Ltd Overcurrent protective circuit
JPH07213073A (en) * 1994-01-14 1995-08-11 Fuji Electric Co Ltd Brightness adjusting method of inverter-device display part
JP2008035659A (en) * 2006-07-31 2008-02-14 Toshiba Mitsubishi-Electric Industrial System Corp Motor driver
JP2009261112A (en) * 2008-04-15 2009-11-05 Nissan Motor Co Ltd Power conversion device
CN102035191A (en) * 2010-12-28 2011-04-27 广东易事特电源股份有限公司 Igbt module over-temperature protection circuit
WO2018193720A1 (en) * 2017-04-19 2018-10-25 株式会社日立製作所 Power conversion device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06209519A (en) * 1993-01-08 1994-07-26 Honda Motor Co Ltd Overcurrent protective circuit
JPH07213073A (en) * 1994-01-14 1995-08-11 Fuji Electric Co Ltd Brightness adjusting method of inverter-device display part
JP2008035659A (en) * 2006-07-31 2008-02-14 Toshiba Mitsubishi-Electric Industrial System Corp Motor driver
JP2009261112A (en) * 2008-04-15 2009-11-05 Nissan Motor Co Ltd Power conversion device
CN102035191A (en) * 2010-12-28 2011-04-27 广东易事特电源股份有限公司 Igbt module over-temperature protection circuit
WO2018193720A1 (en) * 2017-04-19 2018-10-25 株式会社日立製作所 Power conversion device
JP2018179878A (en) * 2017-04-19 2018-11-15 株式会社日立製作所 Power conversion device

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