JP2009053133A - Earth fault detection circuit for vehicle - Google Patents

Earth fault detection circuit for vehicle Download PDF

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JP2009053133A
JP2009053133A JP2007222154A JP2007222154A JP2009053133A JP 2009053133 A JP2009053133 A JP 2009053133A JP 2007222154 A JP2007222154 A JP 2007222154A JP 2007222154 A JP2007222154 A JP 2007222154A JP 2009053133 A JP2009053133 A JP 2009053133A
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ground fault
coupling capacitor
vehicle
detection circuit
waveform
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JP4974814B2 (en
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Toru Aoki
亨 青木
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Marelli Corp
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Calsonic Kansei Corp
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass
    • H02H3/17—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass by means of an auxiliary voltage injected into the installation to be protected
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/02—Details
    • H02H3/04—Details with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned
    • H02H3/044—Checking correct functioning of protective arrangements, e.g. by simulating a fault

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide an earth fault detection circuit for a vehicle which can fully detect a short-circuit failure or an open failure of a coupling capacitor while restraining addition of components. <P>SOLUTION: The earth fault detection circuit 1, which detects an earth fault of a high-voltage system electrically insulated with the vehicle body, is equipped with coupling capacitors C1, C2 which disconnect direct-current components to the high-voltage system, detects the earth fault of the high-voltage system, and detects the severance of wire or short-circuit of the coupling capacitors C1, C2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、高電圧の電源やモーター等の負荷で構成される高電圧系を有する車両の高電圧系における地絡を検出する車両用地絡検出回路の技術分野に属する。   The present invention belongs to the technical field of a ground fault detection circuit for a vehicle that detects a ground fault in a high voltage system of a vehicle having a high voltage system constituted by a load such as a high voltage power source and a motor.

従来では、電気自動車に設けられた高電圧の電源と車体との地絡を検出する技術として、直流電源のプラス母線にカップリングコンデンサ、抵抗を介して接続したインピーダンス変換器にデューティ比５０％の矩形波パルスを入力し、この矩形波パルスの出力を基準電圧と比較し、地絡を検出するようにしている（例えば、特許文献１参照。）。   Conventionally, as a technique for detecting a ground fault between a high-voltage power supply provided in an electric vehicle and a vehicle body, a 50% duty ratio is connected to an impedance converter connected to a positive bus of the DC power supply via a coupling capacitor and a resistor. A rectangular wave pulse is input, and the output of the rectangular wave pulse is compared with a reference voltage to detect a ground fault (see, for example, Patent Document 1).

また、システムメインリレーが高電圧バッテリをインバータ回路に接続した後に、断線検出回路で地絡検出回路とカップリングコンデンサとの接続点の電圧の大きさを所定の断線判定基準電源の電圧と比較し、カップリングコンデンサを含む地絡検出回路から高電圧バッテリに至る経路における断線を検出できるものもある（例えば、特許文献２参照。）。
特開平８−７０５０３号公報（第２−５頁、全図） 特開２００５−２３３８２２号公報（第２−９頁、全図） In addition, after the system main relay connects the high voltage battery to the inverter circuit, the disconnection detection circuit compares the voltage level at the connection point between the ground fault detection circuit and the coupling capacitor with the voltage of the predetermined disconnection determination reference power supply. In some cases, disconnection in a path from a ground fault detection circuit including a coupling capacitor to a high voltage battery can be detected (see, for example, Patent Document 2).
JP-A-8-70503 (page 2-5, full view) Japanese Patent Laying-Open No. 2005-233822 (page 2-9, full view)

しかしながら、従来の車両用地絡検出回路にあっては、カップリングコンデンサのショート故障、オープン故障についての検出が充分でなかった。   However, in the conventional vehicle ground fault detection circuit, detection of a short-circuit failure or an open failure of the coupling capacitor is not sufficient.

本発明は、上記問題点に着目してなされたもので、その目的とするところは、カップリングコンデンサのショート故障、オープン故障についての検出を充分に行うことが、構成の追加を抑制して行うことができる車両用地絡検出回路を提供することにある。   The present invention has been made paying attention to the above-mentioned problems, and the purpose of the present invention is to perform sufficient detection of a coupling capacitor short-circuit failure and open failure while suppressing the addition of a configuration. An object of the present invention is to provide a ground fault detection circuit for a vehicle.

上記目的を達成するため、本発明では、車体と電気的に絶縁された高電圧系の地絡を検出する車両用地絡検出回路において、前記高電圧系との直流成分の遮断を行うカップリングコンデンサを複数設け、複数のカップリングコンデンサを通過させる信号により、前記高電圧系の地絡を検出するとともに、前記カップリングコンデンサの断線、短絡を検出することを特徴とする。   In order to achieve the above object, in the present invention, in a ground fault detection circuit for a vehicle that detects a ground fault of a high voltage system that is electrically insulated from a vehicle body, a coupling capacitor that blocks a DC component from the high voltage system And a ground fault of the high voltage system is detected by a signal passing through the plurality of coupling capacitors, and disconnection or short circuit of the coupling capacitor is detected.

よって、本発明にあっては、カップリングコンデンサのショート故障、オープン故障についての検出を充分に行うことが、構成の追加を抑制して行うことができる。   Therefore, in the present invention, it is possible to sufficiently detect the short-circuit failure and the open failure of the coupling capacitor while suppressing the addition of the configuration.

以下、本発明の車両用地絡検出回路を実現する実施の形態を、請求項１，２，３，４に係る発明に対応する実施例１に基づいて説明する。   Hereinafter, an embodiment for realizing a ground fault detection circuit for a vehicle according to the present invention will be described based on a first embodiment corresponding to the invention according to claims 1, 2, 3, and 4.

まず、構成を説明する。
図１は実施例１の車両用地絡検出回路及び高電圧系の回路図である。
実施例１の車両用地絡検出回路１は、図１に示すように、Ａ／Ｄ入出力部１１、オペアンプＵ１、オペアンプＵ２、制限抵抗Ｒ１、カップリングコンデンサＣ１、カップリングコンデンサＣ２、検出用抵抗Ｒ２を主要な構成としている。 First, the configuration will be described.
1 is a circuit diagram of a vehicle ground fault detection circuit and a high voltage system according to a first embodiment.
As shown in FIG. 1, the vehicle ground fault detection circuit 1 according to the first embodiment includes an A / D input / output unit 11, an operational amplifier U1, an operational amplifier U2, a limiting resistor R1, a coupling capacitor C1, a coupling capacitor C2, and a detection resistor. R2 is the main component.

Ａ／Ｄ入出力部１１は、外部からのデジタル信号をアナログ変換したパルス波形をオペアンプＵ１のプラス入力端子へ出力する。
また、Ａ／Ｄ入出力部１１は、オペアンプＵ２からの出力をデジタル信号に変換して出力する。
オペアンプＵ１は、Ａ／Ｄ入出力部１１からの出力をプラス入力端子へ入力し、自身の出力をマイナス入力端子へ入力するボルテージホロワである。 The A / D input / output unit 11 outputs a pulse waveform obtained by analog conversion of an external digital signal to the plus input terminal of the operational amplifier U1.
The A / D input / output unit 11 converts the output from the operational amplifier U2 into a digital signal and outputs it.
The operational amplifier U1 is a voltage follower that inputs the output from the A / D input / output unit 11 to the positive input terminal and inputs its output to the negative input terminal.

そして、オペアンプＵ１の出力先には、制限抵抗Ｒ１、カップリングコンデンサＣ１を直列に接続する。そして、さらに、第２のカップリングコンデンサＣ２を直列に接続し、オペアンプＵ２のプラス入力端子に接続する。
オペアンプＵ２は、カップリングコンデンサＣ２からの出力をプラス入力端子へ入力し、自身の出力をマイナス入力端子へ入力するボルテージホロワである。 A limiting resistor R1 and a coupling capacitor C1 are connected in series to the output destination of the operational amplifier U1. Further, the second coupling capacitor C2 is connected in series and connected to the positive input terminal of the operational amplifier U2.
The operational amplifier U2 is a voltage follower that inputs the output from the coupling capacitor C2 to the positive input terminal and inputs its output to the negative input terminal.

制限抵抗Ｒ１は、オペアンプＵ１からのパルス波形を調整して、カップリングコンデンサＣ１へ入力する。
カップリングコンデンサＣ２とオペアンプＵ２のプラス入力端子の途中と、グランドの間には、検出用抵抗Ｒ２を設ける。 The limiting resistor R1 adjusts the pulse waveform from the operational amplifier U1 and inputs it to the coupling capacitor C1.
A detection resistor R2 is provided between the coupling capacitor C2 and the positive input terminal of the operational amplifier U2 and the ground.

そして、カップリングコンデンサＣ１とカップリングコンデンサＣ２の間を、高電圧系の電源Ｖ１０のマイナス側の電源ライン２に接続する。
このカップリングコンデンサＣ１とカップリングコンデンサＣ２を介在する接続により、直流成分が遮断される。
さらに、高電圧系の電源Ｖ１０のマイナス側の電源ライン２と、検出用抵抗Ｒ２とグランド間との間に、高電圧系と低電圧系との間の絶縁抵抗として絶縁抵抗Ｒ３を設定する。この絶縁抵抗Ｒ３は通常は１０ＭΩ以上である。
なお、高電圧系は、電源Ｖ１０のみを示すが、その先にモータ等の負荷が設けられたものでよい。 And between the coupling capacitor | condenser C1 and the coupling capacitor | condenser C2, it connects to the power line 2 of the negative | minus side of the high voltage type power supply V10.
The direct current component is cut off by the connection between the coupling capacitor C1 and the coupling capacitor C2.
Further, an insulation resistance R3 is set as an insulation resistance between the high voltage system and the low voltage system between the power line 2 on the negative side of the high voltage system power supply V10 and between the detection resistor R2 and the ground. This insulation resistance R3 is usually 10 MΩ or more.
The high voltage system shows only the power supply V10, but it may be provided with a load such as a motor ahead.

車両用地絡検出回路１のＡ／Ｄ入出力部１１には、外部に設けられるＣＰＵ３を接続する。ＣＰＵ３は、Ａ／Ｄ変換するとパルス波形となるデジタル信号をＡ／Ｄ入出力部１１に出力するとともに、別系統によるＡ／Ｄ入出力部１１からの波形信号に対して、そのパルス波形の立下り直前の電圧１００の電圧等（詳細は後述する）をデジタル信号の波形形状から検出し、その検出内容に応じて判断を行う。
なお、ＣＰＵ３は、パルス波形出力と、検出波形の判断を行う回路を別にそれぞれ設ける構成であってもよいし、それらの回路をチップ化したものであってもよい。 An external CPU 3 is connected to the A / D input / output unit 11 of the vehicle ground fault detection circuit 1. The CPU 3 outputs a digital signal having a pulse waveform upon A / D conversion to the A / D input / output unit 11, and generates a pulse waveform for the waveform signal from the A / D input / output unit 11 of another system. The voltage etc. of the voltage 100 immediately before going down (details will be described later) are detected from the waveform shape of the digital signal, and a determination is made according to the detected contents.
The CPU 3 may have a configuration in which circuits for determining a pulse waveform output and a detection waveform are separately provided, or those circuits may be formed as a chip.

作用を説明する。
[地絡、コンデンサオープン、コンデンサショート検出作用]
図２は実施例１の車両用地絡検出回路の入力波形及び検出波形を示す図である。図３は実施例１の車両用地絡検出回路における地絡状態、コンデンサショート状態、コンデンサオープン状態の検出波形を示す図である。図４は実施例１の車両用地絡検出回路における通常状態の入力波形及び検出波形を示す図である。図５は実施例１の車両用地絡検出回路における地絡状態の入力波形及び検出波形を示す図である。図６は実施例１の車両用地絡検出回路におけるコンデンサオープン状態の入力波形及び検出波形を示す図である。図７は実施例１の車両用地絡検出回路におけるカップリングコンデンサＣ１のコンデンサショート状態の入力波形及び検出波形を示す図である。図８は実施例１の車両用地絡検出回路におけるカップリングコンデンサＣ２のコンデンサショート状態の入力波形及び検出波形を示す図である。 The operation will be described.
[Ground fault, capacitor open, capacitor short detection]
FIG. 2 is a diagram illustrating an input waveform and a detection waveform of the vehicle ground fault detection circuit according to the first embodiment. FIG. 3 is a diagram illustrating detection waveforms of a ground fault state, a capacitor short state, and a capacitor open state in the vehicle ground fault detection circuit according to the first embodiment. FIG. 4 is a diagram illustrating an input waveform and a detection waveform in a normal state in the vehicle ground fault detection circuit according to the first embodiment. FIG. 5 is a diagram illustrating an input waveform and a detection waveform in a ground fault state in the vehicle ground fault detection circuit according to the first embodiment. FIG. 6 is a diagram illustrating an input waveform and a detection waveform in a capacitor open state in the vehicle ground fault detection circuit according to the first embodiment. FIG. 7 is a diagram illustrating an input waveform and a detection waveform in a capacitor short state of the coupling capacitor C1 in the vehicle ground fault detection circuit according to the first embodiment. FIG. 8 is a diagram illustrating an input waveform and a detection waveform in a capacitor short state of the coupling capacitor C2 in the vehicle ground fault detection circuit according to the first embodiment.

実施例１の車両用地絡検出回路１では、Ａ／Ｄ入出力部１１からオペアンプＵ１へ入力したパルス波形は、オペアンプＵ１によりインピーダンス変換されて制限抵抗Ｒ１へ出力される（図２(a)，図４(a)〜図８(a)参照）。
そして制限抵抗Ｒ１により調整されたパルス波形の直流成分は、カップリングコンデンサＣ１で遮断され、変動成分のみが通過することになる。
この変動成分の波形は、一部がカップリングコンデンサＣ２と検出用抵抗Ｒ２を介してグランドへ向かい、また一部が高電圧系の絶縁抵抗Ｒ３を介してグランドへ向かうことになる。 In the vehicle ground fault detection circuit 1 according to the first embodiment, the pulse waveform input from the A / D input / output unit 11 to the operational amplifier U1 is impedance-converted by the operational amplifier U1 and output to the limiting resistor R1 (FIG. 2 (a), FIG. 4 (a) to FIG. 8 (a)).
The direct current component of the pulse waveform adjusted by the limiting resistor R1 is blocked by the coupling capacitor C1, and only the fluctuation component passes.
A part of the waveform of the fluctuation component is directed to the ground via the coupling capacitor C2 and the detection resistor R2, and a part is directed to the ground via the high-voltage insulation resistor R3.

実施例１の車両用地絡検出回路１では、第２のカップリングコンデンサとして設けたカップリングコンデンサＣ２と検出用抵抗Ｒ２との間から検出信号を抽出し、オペアンプＵ２によりインピーダンス変換して、Ａ／Ｄ入出力部１１へ出力する。
この検出波形は、パルス波形の直流成分が遮断され、変動分が通過して成形するため、パルス波形の立上り後、立下りまでの一定区間では、波形電圧値が時間と共に低下していく波形となる（図２(b)，図４(b)参照）。 In the vehicle ground fault detection circuit 1 of the first embodiment, a detection signal is extracted from between the coupling capacitor C2 provided as the second coupling capacitor and the detection resistor R2, and impedance conversion is performed by the operational amplifier U2. Output to the D input / output unit 11.
This detection waveform is formed by blocking the DC component of the pulse waveform and passing the fluctuation, so that the waveform voltage value decreases with time in a certain interval after the pulse waveform rises and falls. (Refer to FIG. 2 (b) and FIG. 4 (b)).

この波形電圧値の低下の時定数τは、カップリングコンデンサＣ１，Ｃ２、検出用抵抗Ｒ２、高電圧系の絶縁抵抗Ｒ３により決定されることになる。
この際の波形電圧値の立下り直前の電圧１００の電圧値をＶとする。
このパルス波形の立下り直前の電圧１００の電圧値Ｖは、Ａ／Ｄ入出力部１１からのデジタル波形出力を入力したＣＰＵ３により、判断処理がされ、電圧値Ｖが認識される。
なお、通常時の電圧値ＶをＶ０とするとＶ０は、通常時における検出波形又は予めデータとして、ＣＰＵ３又は接続される記憶手段に記憶されるものとする。 The time constant τ for decreasing the waveform voltage value is determined by the coupling capacitors C1 and C2, the detection resistor R2, and the high-voltage insulation resistance R3.
At this time, the voltage value of the voltage 100 immediately before the fall of the waveform voltage value is V.
The voltage value V of the voltage 100 immediately before the fall of the pulse waveform is subjected to determination processing by the CPU 3 to which the digital waveform output from the A / D input / output unit 11 is input, and the voltage value V is recognized.
When the normal voltage value V is V0, V0 is stored in the CPU 3 or a storage unit connected as a detection waveform or data in advance at the normal time.

（高電圧系の地絡時）
実施例１において、高電圧系に地絡が発生すると、絶縁抵抗Ｒ３の抵抗値が１０ＭΩ以上から１００ｋΩ以下になる。
すると、検出波形の時定数τを決定する抵抗値が低下することにより、時定数τが小さくなる。そのため、入力パルス波形の変動分である検出波形の減衰を速めることになるため、立下り直前の電圧１００の電圧値Ｖは、Ｖ０より低い値のＶ１となる（図３(a)，図５参照）。
この違いを検出波形からＣＰＵ３で比較判断することにより地絡を検出する。 (During high-voltage system ground fault)
In the first embodiment, when a ground fault occurs in the high voltage system, the resistance value of the insulation resistance R3 becomes 10 MΩ or more and 100 kΩ or less.
As a result, the resistance value that determines the time constant τ of the detected waveform decreases, so that the time constant τ decreases. Therefore, since the attenuation of the detection waveform, which is the fluctuation of the input pulse waveform, is accelerated, the voltage value V of the voltage 100 immediately before the falling becomes a value V1 lower than V0 (FIGS. 3A and 5). reference).
This difference is detected by the CPU 3 from the detected waveform and a ground fault is detected.

（カップリングコンデンサのショート時）
実施例１において、カップリングコンデンサＣ１のショートが発生すると、検出波形の時定数τを決定するコンデンサ容量は、直列配置の容量がなくなることにより増加することになる。そのため、検出波形の時定数τは大きくなる。そのため、入力パルス波形の変動分である検出波形の減衰を遅くすることになるため、立下り直前の電圧１００の電圧値Ｖは、Ｖ０より高い値のＶ２となる（図３(b),図７参照）。 (When coupling capacitor is shorted)
In the first embodiment, when the coupling capacitor C1 is short-circuited, the capacitance of the capacitor that determines the time constant τ of the detected waveform increases due to the absence of the capacitance in series. Therefore, the time constant τ of the detected waveform becomes large. For this reason, the attenuation of the detection waveform, which is the fluctuation of the input pulse waveform, is delayed, so that the voltage value V of the voltage 100 immediately before the fall becomes a value V2 higher than V0 (FIG. 3 (b), FIG. 7).

次に、カップリングコンデンサＣ２にショートが発生した場合には、カップリングコンデンサＣ１のショートの場合と同様に、立下り直前の電圧１００の電圧値Ｖは、Ｖ０より高い値のＶ２となる（図３(b),図８参照）。
このように実施例１では、検出波形からＣＰＵ３で比較判断することによりカップリングコンデンサＣ１又はカップリングコンデンサＣ２のショートを検出することができる。 Next, when a short-circuit occurs in the coupling capacitor C2, the voltage value V of the voltage 100 immediately before the fall becomes a value V2 higher than V0, as in the case of the short-circuit of the coupling capacitor C1 (FIG. 3 (b), see FIG.
As described above, in the first embodiment, it is possible to detect a short circuit of the coupling capacitor C1 or the coupling capacitor C2 by making a comparison determination using the detected waveform by the CPU 3.

また、図示して説明しないが、カップリングコンデンサＣ１とカップリングコンデンサＣ２の両方がショートした場合には、非常に時定数τが小さくなり、立下り直前の電圧１００の電圧値Ｖは非常に小さくなるため、その場合でも同様に検出波形によりＣＰＵ３により検出される。なお、この際の検出波形の立下り直前の電圧１００の電圧値Ｖは、地絡検出の際の電圧値Ｖ１よりもさらに低い値となるため、検出が可能であることを付言しておく。   Although not illustrated and described, when both the coupling capacitor C1 and the coupling capacitor C2 are short-circuited, the time constant τ becomes very small, and the voltage value V of the voltage 100 immediately before the falling is very small. Therefore, even in that case, the CPU 3 similarly detects the detected waveform. Note that the voltage value V of the voltage 100 immediately before the fall of the detection waveform at this time is lower than the voltage value V1 at the time of detecting the ground fault, so that it can be detected.

（カップリングコンデンサのオープン時）
実施例１において、カップリングコンデンサＣ１のオープンが発生すると、入力パルス波形の変動分も通過できなくなる。そのため、検出波形はフラットな波形となる（図３(c)，図６参照）。
次に、カップリングコンデンサＣ２のオープンが発生した場合、カップリングコンデンサＣ２では、入力パルスの変動分が通過できなくなる。しかし、カップリングコンデンサＣ１から絶縁抵抗Ｒ３、そして検出用抵抗Ｒ２を介してオペアンプＵ２へ至る信号経路では、カップリングコンデンサＣ１を通過する入力パルス波形の変動分が流れようとする。しかしながら、絶縁抵抗が非常に大きいため、結果的には、検出波形はフラットとなる。
このように実施例１では、検出波形からＣＰＵ３で比較判断することによりカップリングコンデンサＣ１又はカップリングコンデンサＣ２のオープンを検出することができる。 (When coupling capacitor is open)
In the first embodiment, when the coupling capacitor C1 is opened, the fluctuation of the input pulse waveform cannot be passed. Therefore, the detected waveform is a flat waveform (see FIGS. 3C and 6).
Next, when the coupling capacitor C2 is opened, the fluctuation of the input pulse cannot pass through the coupling capacitor C2. However, in the signal path from the coupling capacitor C1 to the operational amplifier U2 via the insulation resistor R3 and the detection resistor R2, the fluctuation of the input pulse waveform passing through the coupling capacitor C1 tends to flow. However, since the insulation resistance is very large, the detection waveform is flat as a result.
As described above, in the first embodiment, it is possible to detect the open of the coupling capacitor C1 or the coupling capacitor C2 by making a comparison judgment with the CPU 3 from the detected waveform.

なお、図４〜図８に示す実際の検出例では、立下り直前の電圧１００の電圧値Ｖは、正常時に約２Ｖ、地絡時に約０．８Ｖ、コンデンサショート時に約２．５Ｖ、コンデンサオープン時に０Ｖとなり、充分にＣＰＵ３で判断可能となった。
このように実施例１の車両用地絡検出回路では、高電圧系の地絡を確実に行うとともに、地絡検出の構成のために判断している検出電圧値により特段の構成を追加することなく、カップリングコンデンサの異常を検出する。 In the actual detection examples shown in FIGS. 4 to 8, the voltage value V of the voltage 100 immediately before the fall is about 2V at normal time, about 0.8V at the time of ground fault, about 2.5V at the time of capacitor short, and the capacitor open. Sometimes it became 0V, and the CPU 3 was able to judge sufficiently.
As described above, in the vehicle ground fault detection circuit according to the first embodiment, the ground fault of the high voltage system is reliably performed, and a special configuration is not added depending on the detected voltage value determined for the configuration of the ground fault detection. Detect coupling capacitor abnormality.

次に、効果を説明する。   Next, the effect will be described.

実施例１の車両用地絡検出回路にあっては、下記に列挙する効果を得ることができる。   In the vehicle ground fault detection circuit according to the first embodiment, the effects listed below can be obtained.

(1)車体と電気的に絶縁された高電圧系の地絡を検出する車両用地絡検出回路１において、高電圧系との直流成分の遮断を行うカップリングコンデンサＣ１，Ｃ２を設け、複数のカップリングコンデンサＣ１，Ｃ２を通過させる信号により、高電圧系の地絡を検出するとともに、カップリングコンデンサＣ１，Ｃ２の断線、短絡を検出するため、カップリングコンデンサＣ１，Ｃ２のショート故障、オープン故障についての検出を充分に行うことが、構成の追加を抑制して行うことができる。   (1) In a vehicle ground fault detection circuit 1 that detects a ground fault of a high voltage system that is electrically insulated from a vehicle body, coupling capacitors C1 and C2 that cut off a DC component from the high voltage system are provided. A short-circuit failure or an open failure of the coupling capacitors C1 and C2 in order to detect a ground fault in the high voltage system by a signal passing through the coupling capacitors C1 and C2, and to detect disconnection and short-circuit of the coupling capacitors C1 and C2. It is possible to perform the detection with respect to the above while suppressing the addition of the configuration.

(2) (1)において、複数のカップリングコンデンサは、第１のカップリングコンデンサＣ１と第２のカップリングコンデンサＣ２を直列に配置し、第１のカップリングコンデンサＣ１と第２のカップリングコンデンサＣ２の間を高電圧系の電源ライン２との接続部としたため、高電圧系との直流成分の遮断を行いつつ、カップリングコンデンサＣ１，Ｃ２を直列に通過する信号により、高電圧系の地絡を検出し、且つ直列に配置したカップリングコンデンサＣ１，Ｃ２の容量変化が通過させる信号に与える変化により、カップリングコンデンサＣ１，Ｃ２のショート故障、オープン故障（短絡・断線）の検出を充分に行うことが、構成の追加を抑制して行うことができる。   (2) In (1), the plurality of coupling capacitors include a first coupling capacitor C1 and a second coupling capacitor C2 arranged in series, and the first coupling capacitor C1 and the second coupling capacitor. Since the connection portion between C2 and the high-voltage system power supply line 2 is used, a high-voltage system ground is detected by a signal passing through the coupling capacitors C1 and C2 in series while blocking the DC component from the high-voltage system. Detection of short-circuit faults and open faults (short-circuits / disconnections) of coupling capacitors C1 and C2 are sufficiently detected by detecting changes in capacitance and changing the capacitance of coupling capacitors C1 and C2 arranged in series to the signal to be passed. This can be done while suppressing the addition of configurations.

(3) (2)において、第１のカップリングコンデンサＣ１及び第２のカップリングコンデンサＣ２に通過させるようにパルス波形を出力するＣＰＵ３及びＡ／Ｄ入出力部１１、オペアンプＵ１と、第２カップリングコンデンサＣ２からグランドまでの間に直列に配置した検出用抵抗Ｒ２と、第２カップリングコンデンサＣ２と検出用抵抗Ｒ２との間から検出信号を抽出するＡ／Ｄ入出力部１１及びオペアンプＵ２、ＣＰＵ３を備え、高電圧系の絶縁抵抗Ｒ３が、高電圧系との接続部とグランド間に設けられるようにしたため、高電圧系の絶縁抵抗Ｒ３の地絡により絶縁抵抗が低下し、これにより検出信号の時定数が小さくなることにより地絡が検出でき、また、第１及び第２のカップリングコンデンサＣ１，Ｃ２のショート時には、コンデンサ容量が大きくなり、これにより検出信号の時定数が大きくなることによりコンデンサショートが検出でき、オープン時には、検出信号がフラットになることによりコンデンサオープンが検出でき、このようにして、カップリングコンデンサＣ１，Ｃ２のショート故障、オープン故障についての検出を充分に行うことが、構成の追加を抑制して行うことができる。   (3) In (2), the CPU 3 and the A / D input / output unit 11, the operational amplifier U1, and the second cup for outputting a pulse waveform so as to pass through the first coupling capacitor C1 and the second coupling capacitor C2. A detection resistor R2 arranged in series between the ring capacitor C2 and the ground, an A / D input / output unit 11 and an operational amplifier U2 for extracting a detection signal from between the second coupling capacitor C2 and the detection resistor R2, Since the CPU 3 is provided and the high voltage system insulation resistance R3 is provided between the connection to the high voltage system and the ground, the insulation resistance is reduced due to the ground fault of the high voltage system insulation resistance R3, thereby detecting The ground fault can be detected by reducing the time constant of the signal, and when the first and second coupling capacitors C1 and C2 are short-circuited, the capacitor capacitance is detected. This increases the time constant of the detection signal, so that a capacitor short can be detected. When the capacitor is open, the detection signal becomes flat so that the capacitor open can be detected. In this way, the coupling capacitors C1, C2 are detected. It is possible to sufficiently detect the short-circuit failure and the open failure of the device while suppressing the addition of the configuration.

(4) (3)において、Ａ／Ｄ入出力部１１及びオペアンプＵ２、ＣＰＵ３による検出信号の波形の立下り直前の電圧値の通常状態の値と検出値との比較により高電圧系の地絡、第１、第２のカップリングコンデンサＣ１，Ｃ２の断線及び短絡を判断する判断手段を備えたため、高電圧系の絶縁抵抗Ｒ３の地絡により絶縁抵抗が低下し、これにより検出信号の時定数が小さくなり、検出信号の波形の立下り直前の電圧値が通常より低くなることにより地絡が検出でき、また、第１及び第２のカップリングコンデンサＣ１，Ｃ２のショート時には、コンデンサ容量が大きくなり、これにより検出信号の時定数が大きくなり、検出信号の波形の立下り直前の電圧値が通常より高くなることによりコンデンサショートが検出でき、オープン時には、検出信号がフラットになることによりコンデンサオープンが検出でき、このようにして、カップリングコンデンサＣ１，Ｃ２のショート故障、オープン故障についての検出を充分に行うことが、構成の追加を抑制して行うことができる。   (4) In (3), the ground fault of the high voltage system is obtained by comparing the detected value with the normal value of the voltage value immediately before the fall of the waveform of the detection signal by the A / D input / output unit 11 and the operational amplifier U2 and CPU3. Since the judgment means for judging the disconnection and the short circuit of the first and second coupling capacitors C1 and C2 is provided, the insulation resistance is lowered due to the ground fault of the insulation resistor R3 of the high voltage system, and thereby the time constant of the detection signal , And the voltage value immediately before the falling of the waveform of the detection signal becomes lower than usual, so that a ground fault can be detected. Also, when the first and second coupling capacitors C1 and C2 are short-circuited, the capacitor capacity is large. As a result, the time constant of the detection signal increases, and the voltage shortly before the falling edge of the waveform of the detection signal becomes higher than normal, so that a capacitor short circuit can be detected. Since the capacitor becomes flat, the capacitor open can be detected. In this way, the detection of the short-circuit failure and the open failure of the coupling capacitors C1 and C2 can be sufficiently performed while suppressing the addition of the configuration. .

以上、本発明の車両用地絡検出回路を実施例１に基づき説明してきたが、具体的な構成については、これらの実施例に限られるものではなく、特許請求の範囲の各請求項に係る発明の要旨を逸脱しない限り、設計の変更や追加等は許容される。   The vehicle ground fault detection circuit of the present invention has been described based on the first embodiment. However, the specific configuration is not limited to these embodiments, and the invention according to each claim of the claims. Design changes and additions are permitted without departing from the gist of the present invention.

例えば、実施例１では、ＣＰＵ３とＡ／Ｄ入出力部１１により、検出信号としてのパルス信号の生成及び入力、出力及び判断処理を行ったが、他の構成、例えば、検出信号の生成手段や、出力波形から立下り直前の電圧値の判断手段などを設ける構成であってもよい。   For example, in the first embodiment, the CPU 3 and the A / D input / output unit 11 perform generation, input, output, and determination processing of a pulse signal as a detection signal, but other configurations, for example, detection signal generation means, A configuration may be provided in which means for determining a voltage value immediately before the fall from the output waveform is provided.

実施例１の車両用地絡検出回路及び高電圧系の回路図である。1 is a circuit diagram of a vehicle ground fault detection circuit and a high voltage system according to a first embodiment. 実施例１の車両用地絡検出回路の入力波形及び検出波形を示す図である。It is a figure which shows the input waveform and detection waveform of the ground fault detection circuit for vehicles of Example 1. FIG. 実施例１の車両用地絡検出回路における地絡状態、コンデンサショート状態、コンデンサオープン状態の検出波形を示す図である。It is a figure which shows the detection waveform of the ground fault state in a vehicle ground fault detection circuit of Example 1, a capacitor | condenser short state, and a capacitor | condenser open state. 実施例１の車両用地絡検出回路における通常状態の入力波形及び検出波形を示す図である。It is a figure which shows the input waveform and detection waveform of a normal state in the vehicle ground fault detection circuit of Example 1. FIG. 実施例１の車両用地絡検出回路における地絡状態の入力波形及び検出波形を示す図である。It is a figure which shows the input waveform and detection waveform of a ground fault state in the vehicle ground fault detection circuit of Example 1. FIG. 実施例１の車両用地絡検出回路におけるコンデンサオープン状態の入力波形及び検出波形を示す図である。It is a figure which shows the input waveform and detection waveform of a capacitor | condenser open state in the vehicle ground fault detection circuit of Example 1. FIG. 実施例１の車両用地絡検出回路におけるカップリングコンデンサＣ１のコンデンサショート状態の入力波形及び検出波形を示す図である。It is a figure which shows the input waveform and detection waveform of the capacitor | condenser short-circuit state of the coupling capacitor | condenser C1 in the vehicle ground fault detection circuit of Example 1. FIG. 図８は実施例１の車両用地絡検出回路におけるカップリングコンデンサＣ２のコンデンサショート状態の入力波形及び検出波形を示す図である。FIG. 8 is a diagram illustrating an input waveform and a detection waveform in a capacitor short state of the coupling capacitor C2 in the vehicle ground fault detection circuit according to the first embodiment.

符号の説明Explanation of symbols

１ 車両用地絡検出回路
２ 電源ライン
３ ＣＰＵ
１１ Ａ／Ｄ入出力部
１００ 立下り直前の電圧
Ｃ１ カップリングコンデンサ
Ｃ２ カップリングコンデンサ
Ｒ１ 制限抵抗
Ｒ２ 検出用抵抗
Ｒ３ 絶縁抵抗
Ｕ１ オペアンプ
Ｕ２ オペアンプ
Ｖ１０ 電源 DESCRIPTION OF SYMBOLS 1 Ground fault detection circuit for vehicles 2 Power supply line 3 CPU
11 A / D input / output unit 100 voltage just before falling C1 coupling capacitor C2 coupling capacitor R1 limiting resistor R2 detection resistor R3 insulation resistance U1 operational amplifier U2 operational amplifier V10 power supply

Claims (4)

車体と電気的に絶縁された高電圧系の地絡を検出する車両用地絡検出回路において、
前記高電圧系との直流成分の遮断を行うカップリングコンデンサを複数設け、
複数のカップリングコンデンサを通過させる信号により、前記高電圧系の地絡を検出するとともに、前記カップリングコンデンサの断線、短絡を検出することを特徴とする車両用地絡検出回路。 In a vehicle ground fault detection circuit that detects a ground fault of a high voltage system that is electrically insulated from the vehicle body,
Providing a plurality of coupling capacitors that cut off the DC component with the high voltage system,
A ground fault detection circuit for a vehicle, wherein a ground fault of the high voltage system is detected by a signal passing through a plurality of coupling capacitors, and disconnection or short circuit of the coupling capacitor is detected. 請求項１に記載の車両用地絡検出回路において、
複数のカップリングコンデンサは、第１のカップリングコンデンサと第２のカップリングコンデンサを直列に配置し、第１のカップリングコンデンサと第２のカップリングコンデンサの間を高電圧系との接続部とした、
ことを特徴とする車両用地絡検出回路。 The ground fault detection circuit for a vehicle according to claim 1,
In the plurality of coupling capacitors, a first coupling capacitor and a second coupling capacitor are arranged in series, and a connection portion between the first coupling capacitor and the second coupling capacitor and a high voltage system is provided. did,
A ground fault detection circuit for a vehicle. 請求項２に記載の車両用地絡検出回路において、
第１のカップリングコンデンサ及び第２のカップリングコンデンサに通過させるようにパルス波形を出力するパルス波形出力手段と、
前記第２カップリングコンデンサからグランドまでの間に直列に配置した検出用抵抗と、
前記第２カップリングコンデンサと前記検出用抵抗との間から検出信号を抽出する検出信号抽出手段と、
を備え、
高電圧系の絶縁抵抗が、高電圧系との前記接続部とグランド間に設けられるようにした、
ことを特徴とする車両用地絡検出回路。 In the vehicle ground fault detection circuit according to claim 2,
Pulse waveform output means for outputting a pulse waveform so as to pass through the first coupling capacitor and the second coupling capacitor;
A detection resistor arranged in series between the second coupling capacitor and the ground;
Detection signal extraction means for extracting a detection signal from between the second coupling capacitor and the detection resistor;
With
The high voltage system insulation resistance was provided between the connection with the high voltage system and the ground.
A ground fault detection circuit for a vehicle. 請求項３に記載の車両用地絡検出回路において、
前記検出信号抽出手段による検出信号の波形の立下り直前の電圧値の通常状態の値と検出値との比較により高電圧系の地絡、第１、第２のカップリングコンデンサの断線及び短絡を判断する判断手段を備えた、
ことを特徴とする車両用地絡検出回路。 In the vehicle ground fault detection circuit according to claim 3,
By comparing the detection value with the normal value of the voltage value immediately before the detection signal waveform falls by the detection signal extraction means, the ground fault of the high voltage system, the disconnection and the short circuit of the first and second coupling capacitors are detected. Equipped with judgment means to judge,
A ground fault detection circuit for a vehicle.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102483436A (en) * 2009-09-24 2012-05-30 日产自动车株式会社 Apparatus and method for detecting abnormality of high voltage circuit
CN102539961A (en) * 2010-12-20 2012-07-04 矢崎总业株式会社 Apparatus for detecting fault of flying capacitor of insulated condition detecting unit
US11269019B2 (en) 2019-02-25 2022-03-08 Denso Corporation Voltage detection apparatus
EP4068544A4 (en) * 2019-11-26 2023-01-18 SANYO Electric Co., Ltd. Earth leakage detection device and vehicle power supply system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004053367A (en) * 2002-07-18 2004-02-19 Nissan Motor Co Ltd Diagnostic device for ground fault detection circuit
JP2004104923A (en) * 2002-09-10 2004-04-02 Matsushita Electric Ind Co Ltd Method and apparatus for detecting insulation resistance
JP2004347372A (en) * 2003-05-20 2004-12-09 Denso Corp Coupling capacitor-type electric leak detector for on-vehicle ground-insulated circuit
JP2005091224A (en) * 2003-09-18 2005-04-07 Denso Corp Earth detector
JP2005233822A (en) * 2004-02-20 2005-09-02 Denso Corp Earth fault detector

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004053367A (en) * 2002-07-18 2004-02-19 Nissan Motor Co Ltd Diagnostic device for ground fault detection circuit
JP2004104923A (en) * 2002-09-10 2004-04-02 Matsushita Electric Ind Co Ltd Method and apparatus for detecting insulation resistance
JP2004347372A (en) * 2003-05-20 2004-12-09 Denso Corp Coupling capacitor-type electric leak detector for on-vehicle ground-insulated circuit
JP2005091224A (en) * 2003-09-18 2005-04-07 Denso Corp Earth detector
JP2005233822A (en) * 2004-02-20 2005-09-02 Denso Corp Earth fault detector

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102483436A (en) * 2009-09-24 2012-05-30 日产自动车株式会社 Apparatus and method for detecting abnormality of high voltage circuit
US8749247B2 (en) 2009-09-24 2014-06-10 Nissan Motor Co., Ltd. Apparatus and method for detecting abnormality of high voltage circuit
CN102539961A (en) * 2010-12-20 2012-07-04 矢崎总业株式会社 Apparatus for detecting fault of flying capacitor of insulated condition detecting unit
JP2012132725A (en) * 2010-12-20 2012-07-12 Yazaki Corp Flying capacitor failure detector of insulation state detection unit
US11269019B2 (en) 2019-02-25 2022-03-08 Denso Corporation Voltage detection apparatus
EP4068544A4 (en) * 2019-11-26 2023-01-18 SANYO Electric Co., Ltd. Earth leakage detection device and vehicle power supply system

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