WO2021235302A1 - Current detection device - Google Patents

Current detection device Download PDF

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Publication number
WO2021235302A1
WO2021235302A1 PCT/JP2021/018133 JP2021018133W WO2021235302A1 WO 2021235302 A1 WO2021235302 A1 WO 2021235302A1 JP 2021018133 W JP2021018133 W JP 2021018133W WO 2021235302 A1 WO2021235302 A1 WO 2021235302A1
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Prior art keywords
power supply
converter
shunt resistor
current detection
circuit unit
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PCT/JP2021/018133
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French (fr)
Japanese (ja)
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保 遠藤
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Koa株式会社
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Publication of WO2021235302A1 publication Critical patent/WO2021235302A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00

Definitions

  • the present invention relates to a current detector equipped with a shunt resistor.
  • a current detection device equipped with a shunt resistor is used to detect a current in a power semiconductor device or the like.
  • the shunt resistor and the circuit unit are connected to each other via a connector via an output terminal and a ground terminal.
  • an object of the present invention is to provide a current detection device capable of detecting a disconnected state of a connector.
  • the current detection device of one aspect of the present invention is a current detection device including a shunt resistor and a circuit unit detachably connected to the shunt resistor, and the circuit unit is an AD converter. It has a power supply unit that supplies a voltage to the AD converter, and between the shunt resistor and the circuit unit, a first ground terminal connected to the AD converter and the power supply unit. It is characterized in that a second ground terminal to be connected is provided separately.
  • the current detection device of the present invention it is possible to detect the unconnected state of the connector.
  • FIG. 5a is a graph showing an example of the waveform of the voltage signal detected when the connector is not connected in the embodiment of the present invention
  • FIG. 5b is a graph showing the voltage detected when the connector is not connected in the comparative example. It is a graph which showed an example of the waveform of a signal.
  • the current detection device 10 of the present embodiment includes a shunt resistor 1 and a circuit unit 2.
  • the shunt resistor 1 and the circuit unit 2 are detachably connected via a connector.
  • the structure of the shunt resistor 1 shown in FIG. 1 is not limited, and an existing shunt resistor can be applied.
  • the shunt resistor 1 and the circuit unit 2 are electrically connected via a cable 11.
  • Four cables 11 are prepared, and the shunt resistor 1 and the cable 11 are the first signal output terminal (connector) T1, the second signal output terminal (connector) T2, the first ground terminal (connector) T3, and the first. 2 Connected via the ground terminal (connector) T4.
  • the circuit unit 2 and the cable 11 have a first signal output terminal (connector) T5, a second signal output terminal (connector) T6, a first ground terminal (connector) T7, and a second ground terminal (connector) T8. Connected via.
  • the circuit unit 2 includes an isolated power supply 5, an isolated amplifier 6, an operational amplifier 9, and the like.
  • the isolated power supply 5 is an isolated DC / DC converter, and the primary power supply of the isolated power supply 5 has a power supply voltage of Vcc1 and the secondary power supply has a power supply voltage of Vcc2.
  • the isolated amplifier 6 is composed of an AD converter 7 (analog / digital conversion unit) and a DA converter 8 (digital / analog conversion unit).
  • the AD converter 7 and the DA converter 8 have an insulating structure.
  • the insulation amplifier 6 it is preferable to use a delta-sigma insulation amplifier such as a photocoupler or an electrostatic coupling capacitor. Since a high voltage is supplied from the shunt resistor 1 to the circuit unit 2, an insulating amplifier 6 is used in order to reduce the voltage and properly operate a microcomputer (not shown).
  • a path for supplying the power supply voltage Vcc1 to the AD converter 7 from the primary side power supply of the isolated power supply 5 is provided, and the DA is provided from the secondary side power supply of the isolated power supply 5.
  • the converter 8 is provided with a path to which the power supply voltage Vcc2 is supplied. In this way, the power supply 5 is divided into an AD converter 7 and a DA converter 8 of the insulation amplifier 6.
  • the input unit of the AD converter 7 and the first signal output terminal T5 and the second signal output terminal T6 are electrically connected via resistors R1 and R2.
  • the shunt resistor 1 and the circuit unit 2 are connected, the voltage detected by the shunt resistor 1 is input to the AD converter 7, and the analog signal is input to the AD converter 7. Is converted into a digital signal and transmitted to the DA converter 8 in an isolated manner.
  • the AD converter 7 can be in the high voltage region and the DA converter 8 can be in the low voltage region.
  • the isolated digital signal is converted into an analog signal.
  • the non-inverting output section and the inverting output section of the DA converter 8 are connected to each differential input section of the operational amplifier 9 via resistors R3 and R4, and the analog signal (voltage) is amplified by the operational amplifier 9. Will be done.
  • the current detection signal is output from the output unit of the operational amplifier 9.
  • the midpoint potentials of the resistors R8 and R9 are input via the resistor R6 between the inverting output section of the DA converter 8 and the ( ⁇ ) differential input section of the operational amplifier 9. Therefore, the reference potential of the current detection signal (voltage output when the potential difference of the shunt resistor 1 is 0) can be shifted from 0V.
  • the shunt resistor 1 and the circuit unit 2 are connected by four signal lines (cable 11), and two of them are ground wirings.
  • the circuit unit 2 is provided with a first ground terminal T7 and a second ground terminal T8 connected to each ground wiring, and the first ground terminal T7 is connected to the ground GND1b of the AD converter 7 and is connected to the second ground terminal.
  • T8 is connected to the ground GND1a of the primary side power supply of the isolated power supply 5.
  • the ground GND1b of the AD converter 7 and the ground GND1a of the primary side power supply of the isolated power supply 5 are separately separated.
  • the shunt resistor 1 and the circuit unit 2 are connected, the shunt resistor 1, the insulated power supply 5, and the insulated amplifier 6 are electrically connected to each other. Therefore, by the power input, the power supply voltage Vcc1 is supplied to the AD converter 7 from the primary side power supply of the isolated power supply 5, and the power supply voltage Vcc2 is supplied to the DA converter 8 and the operational amplifier 9 from the secondary side power supply of the isolated power supply 5. NS.
  • the potential difference detected by the shunt resistor 1 is detected as a current detection signal via the insulation amplifier 6 and the operational amplifier 9.
  • FIG. 2 shows a state in which the shunt resistor 1 is disconnected from the circuit unit 2 in the current detection device 10 of the present embodiment.
  • the cable 11 and the terminals T5 to T8 of the circuit unit 2 are disconnected from each other, but the cables 11 and the terminals T1 to T4 of the shunt resistor 1 may be disconnected from each other.
  • the current detection signal which is the reference voltage
  • the reference voltage is output as shown in FIG. 5b even when the connector is not connected. That is, when the same signal as the potential difference 0 is input from the first signal output terminal T5 and the second signal output terminal T6 into the AD converter 7, the reference voltage is output.
  • the reference voltage is 2.5V, which is an intermediate potential, and even if the shunt resistor 1 is out of the circuit section 2, 2.5V as the reference potential is output. ..
  • the current detection device 20 of the comparative example cannot appropriately determine the connected state and the unconnected state of the connector.
  • the current detection device 10 of the present embodiment there are four signal lines between the shunt resistor 1 and the circuit unit 2, two of which are output wirings. Yes, two are ground wiring. These ground wirings separately separate the ground GND1b of the AD converter 7 and the ground GND1a of the primary side power supply of the isolated power supply 5. Therefore, as shown in FIG. 2, when the shunt resistor 1 and the connector of the circuit unit 2 are not connected, the primary power supply of the isolated power supply 5 and the AD converter 7 of the isolated amplifier 6 are not electrically connected. Therefore, the power supply voltage Vcc1 is not supplied to the AD converter 7 even by the power supply input. On the other hand, the power supply voltage Vcc2 is supplied to the DA converter 8 on the secondary power supply side of the isolated power supply 5 by the power supply input.
  • FIG. 5a shows an abnormal voltage having an output range of 0 to 5 V and 5 V or more.
  • the unconnected state of the connector can be confirmed by the microcomputer. For example, in the case of the unconnected state, the operator can be immediately notified by an alarm, blinking light, or the like.
  • the cable 11 is arranged between the shunt resistor 1 side and the circuit unit 2 side, and the cable 11 is arranged between the shunt resistor 1 and the cable 11 and the circuit unit 2.
  • Each of the cables 11 has a detachable structure, but only one of them may be detachable. Further, the shunt resistor 1 and the circuit unit 2 may be directly connected via terminals without using the cable 11.
  • an insulating amplifier 6 in which the AD converter 7 and the DA converter 8 are insulated from each other in the circuit unit 2, but the AD converter 7 side may be raised due to a combination with a resistor or the like.
  • the configuration may be such that the voltage region and the DA converter 8 side can be controlled to the low voltage region.
  • a current detection device in which a shunt resistor and a circuit unit can be attached and detached, it is possible to appropriately determine the unconnected state of the connector. As a result, the connection status can be confirmed and the connection work can be performed immediately, and stable current detection can be performed.

Abstract

The purpose of the present invention is to provide a current detection device capable of detecting a non-connection state of a connector. A current detection device (10) according to the present invention is provided with a shunt resistor (1) and a circuit part (2) that is connected to the shunt resistor in an attachable/detachable manner. The current detection device is characterized in that the circuit part has an AD converter (7) and a power supply part for supplying a voltage to the AD converter and that a first ground terminal (T7) connected to the AD converter and a second ground terminal (T8) connected to the power supply part are separately disposed between the shunt resistor and the circuit part.

Description

電流検出装置Current detector
　この発明は、シャント抵抗器を備えた電流検出装置に関する。 The present invention relates to a current detector equipped with a shunt resistor.
　例えば、パワー半導体装置等の電流を検出するために、シャント抵抗器を備えた電流検出装置が用いられる。 For example, a current detection device equipped with a shunt resistor is used to detect a current in a power semiconductor device or the like.
　特許文献１に示す電流検出装置では、シャント抵抗器と回路部とが、出力端子およびグランド端子を介してコネクタ接続されている。 In the current detection device shown in Patent Document 1, the shunt resistor and the circuit unit are connected to each other via a connector via an output terminal and a ground terminal.
特開２０１９－４５１５２号公報Japanese Unexamined Patent Publication No. 2019-45152
　しかしながら、従来のシャント抵抗器を備えた電流検出装置においては、コネクタが外れていても、未接続状態を判断することができなかった。 However, in the conventional current detector equipped with a shunt resistor, it was not possible to determine the unconnected state even if the connector was disconnected.
　そこで本発明は、上記問題に鑑みてなされたもので、コネクタの未接続状態を検知することが可能な電流検出装置を提供することを目的とする。 Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a current detection device capable of detecting a disconnected state of a connector.
　本発明の一態様の電流検出装置は、シャント抵抗器と、前記シャント抵抗器と着脱可能に接続される回路部と、を具備する電流検出装置であって、前記回路部は、ＡＤ変換器と、前記ＡＤ変換器に電圧を供給する電源部とを、有し、前記シャント抵抗器と前記回路部との間には、前記ＡＤ変換器に接続される第１グランド端子と、前記電源部に接続される第２グランド端子とが別々に設けられていることを特徴とする。 The current detection device of one aspect of the present invention is a current detection device including a shunt resistor and a circuit unit detachably connected to the shunt resistor, and the circuit unit is an AD converter. It has a power supply unit that supplies a voltage to the AD converter, and between the shunt resistor and the circuit unit, a first ground terminal connected to the AD converter and the power supply unit. It is characterized in that a second ground terminal to be connected is provided separately.
　本発明の電流検出装置によれば、コネクタの未接続状態を検知することができる。 According to the current detection device of the present invention, it is possible to detect the unconnected state of the connector.
本発明の実施の形態に係る電流検出装置（接続時）の一構成例を示す図である。It is a figure which shows one configuration example of the current detection apparatus (at the time of connection) which concerns on embodiment of this invention. 本発明の実施の形態に係る電流検出装置（未接続時）の一構成例を示す図である。It is a figure which shows one configuration example of the current detection apparatus (when not connected) which concerns on embodiment of this invention. 比較例に係る電流検出装置（接続時）の一構成例を示す図である。It is a figure which shows one configuration example of the current detection device (at the time of connection) which concerns on a comparative example. 比較例に係る電流検出装置（未接続時）の一構成例を示す図である。It is a figure which shows one configuration example of the current detection device (when not connected) which concerns on a comparative example. 図５ａは、本発明の実施の形態において、コネクタの非接続時に検出される電圧信号の波形の一例を示したグラフであり、図５ｂは、比較例において、コネクタの非接続時に検出される電圧信号の波形の一例を示したグラフである。FIG. 5a is a graph showing an example of the waveform of the voltage signal detected when the connector is not connected in the embodiment of the present invention, and FIG. 5b is a graph showing the voltage detected when the connector is not connected in the comparative example. It is a graph which showed an example of the waveform of a signal.
　以下、添付図面を参照して、本実施の形態に係るシャント抵抗器を備えた電流検出装置について説明する。 Hereinafter, the current detection device provided with the shunt resistor according to the present embodiment will be described with reference to the attached drawings.
＜本実施の形態の電流検出装置１０の回路構成＞
　図１に示すように、本実施の形態の電流検出装置１０は、シャント抵抗器１と、回路部２とを備える。シャント抵抗器１と、回路部２とは、コネクタを介して着脱可能に接続される。 <Circuit configuration of the current detection device 10 of this embodiment>
As shown in FIG. 1, the current detection device 10 of the present embodiment includes a shunt resistor 1 and a circuit unit 2. The shunt resistor 1 and the circuit unit 2 are detachably connected via a connector.
　図１に示すシャント抵抗器１の構造を限定するものでなく、既存のシャント抵抗器を適用することができる。 The structure of the shunt resistor 1 shown in FIG. 1 is not limited, and an existing shunt resistor can be applied.
　図１に示すように、シャント抵抗器１と回路部２とは、ケーブル１１を介して電気的に接続されている。ケーブル１１は、４本用意され、シャント抵抗器１とケーブル１１は、第１信号出力端子（コネクタ）Ｔ１、第２信号出力端子（コネクタ）Ｔ２、第１グランド端子（コネクタ）Ｔ３、及び、第２グランド端子（コネクタ）Ｔ４を介して接続される。また、回路部２とケーブル１１は、第１信号出力端子（コネクタ）Ｔ５、第２信号出力端子（コネクタ）Ｔ６、第１グランド端子（コネクタ）Ｔ７、及び、第２グランド端子（コネクタ）Ｔ８を介して接続される。 As shown in FIG. 1, the shunt resistor 1 and the circuit unit 2 are electrically connected via a cable 11. Four cables 11 are prepared, and the shunt resistor 1 and the cable 11 are the first signal output terminal (connector) T1, the second signal output terminal (connector) T2, the first ground terminal (connector) T3, and the first. 2 Connected via the ground terminal (connector) T4. Further, the circuit unit 2 and the cable 11 have a first signal output terminal (connector) T5, a second signal output terminal (connector) T6, a first ground terminal (connector) T7, and a second ground terminal (connector) T8. Connected via.
　図１に示すように、回路部２は、絶縁電源５、絶縁アンプ６、及び、オペアンプ９等を備える。絶縁電源５は、絶縁型ＤＣ／ＤＣコンバータであり、絶縁電源５の一次側電源は、電源電圧がＶｃｃ１であり、二次側電源は、電源電圧がＶｃｃ２である。 As shown in FIG. 1, the circuit unit 2 includes an isolated power supply 5, an isolated amplifier 6, an operational amplifier 9, and the like. The isolated power supply 5 is an isolated DC / DC converter, and the primary power supply of the isolated power supply 5 has a power supply voltage of Vcc1 and the secondary power supply has a power supply voltage of Vcc2.
　図１に示すように、絶縁アンプ６は、ＡＤ変換器７（アナログ／デジタル変換部）とＤＡ変換器８（デジタル／アナログ変換部）によって構成されている。本実施の形態において、ＡＤ変換器７とＤＡ変換器８の間は、絶縁構成とされる。絶縁アンプ６には、例えば、フォトカプラ、静電カップリングコンデンサーなどの、ΔΣ方式絶縁アンプを用いるのが好ましい。シャント抵抗器１からは高電圧が回路部２に供給されるため、電圧を降下させて図示しないマイコンを適切に動作させるべく絶縁アンプ６を用いている。 As shown in FIG. 1, the isolated amplifier 6 is composed of an AD converter 7 (analog / digital conversion unit) and a DA converter 8 (digital / analog conversion unit). In the present embodiment, the AD converter 7 and the DA converter 8 have an insulating structure. As the insulation amplifier 6, it is preferable to use a delta-sigma insulation amplifier such as a photocoupler or an electrostatic coupling capacitor. Since a high voltage is supplied from the shunt resistor 1 to the circuit unit 2, an insulating amplifier 6 is used in order to reduce the voltage and properly operate a microcomputer (not shown).
　図１に示すように、回路部２内では、絶縁電源５の一次側電源から、ＡＤ変換器７に、電源電圧Ｖｃｃ１が供給される経路を備え、絶縁電源５の二次側電源から、ＤＡ変換器８に、電源電圧Ｖｃｃ２が供給される経路を備える。このように、電源５は、絶縁アンプ６のＡＤ変換器７用とＤＡ変換器８用とで分けられる。 As shown in FIG. 1, in the circuit unit 2, a path for supplying the power supply voltage Vcc1 to the AD converter 7 from the primary side power supply of the isolated power supply 5 is provided, and the DA is provided from the secondary side power supply of the isolated power supply 5. The converter 8 is provided with a path to which the power supply voltage Vcc2 is supplied. In this way, the power supply 5 is divided into an AD converter 7 and a DA converter 8 of the insulation amplifier 6.
　図１に示すように、ＡＤ変換器７の入力部と、第１信号出力端子Ｔ５及び第２信号出力端子Ｔ６との間は、抵抗Ｒ１、Ｒ２を介して、電気的に接続される。図１に示すように、シャント抵抗器１と回路部２とが接続された状態では、シャント抵抗器１で検出された電圧が、ＡＤ変換器７へ入力され、ＡＤ変換器７において、アナログ信号からデジタル信号に変換され、ＤＡ変換器８に絶縁伝送される。これにより、ＡＤ変換器７を高電圧領域、ＤＡ変換器８を低電圧領域にできる。 As shown in FIG. 1, the input unit of the AD converter 7 and the first signal output terminal T5 and the second signal output terminal T6 are electrically connected via resistors R1 and R2. As shown in FIG. 1, when the shunt resistor 1 and the circuit unit 2 are connected, the voltage detected by the shunt resistor 1 is input to the AD converter 7, and the analog signal is input to the AD converter 7. Is converted into a digital signal and transmitted to the DA converter 8 in an isolated manner. As a result, the AD converter 7 can be in the high voltage region and the DA converter 8 can be in the low voltage region.
　ＤＡ変換器８では、絶縁伝送されたデジタル信号がアナログ信号に変換される。ＤＡ変換器８の非反転出力部及び反転出力部は、抵抗Ｒ３、Ｒ４を介して、オペアンプ９の各差動入力部に接続されており、アナログ信号（電圧）はオペアンプ９にて、増幅処理される。そして、電流検出信号がオペアンプ９の出力部から出力される。図１に示すように、ＤＡ変換器８の反転出力部と、オペアンプ９の（－）差動入力部との間には、抵抗Ｒ８、Ｒ９の中点電位が抵抗Ｒ６を介して入力されるため、電流検出信号の基準電位（シャント抵抗器１の電位差が０であるときに出力される電圧）を０Ｖからシフトさせることができる。 In the DA converter 8, the isolated digital signal is converted into an analog signal. The non-inverting output section and the inverting output section of the DA converter 8 are connected to each differential input section of the operational amplifier 9 via resistors R3 and R4, and the analog signal (voltage) is amplified by the operational amplifier 9. Will be done. Then, the current detection signal is output from the output unit of the operational amplifier 9. As shown in FIG. 1, the midpoint potentials of the resistors R8 and R9 are input via the resistor R6 between the inverting output section of the DA converter 8 and the (−) differential input section of the operational amplifier 9. Therefore, the reference potential of the current detection signal (voltage output when the potential difference of the shunt resistor 1 is 0) can be shifted from 0V.
　図１に示す本実施の形態では、シャント抵抗器１と回路部２とが４本の信号線（ケーブル１１）で接続され、このうち２本がグランド配線である。回路部２には、各グランド配線に接続される第１グランド端子Ｔ７と第２グランド端子Ｔ８が設けられ、第１グランド端子Ｔ７は、ＡＤ変換器７のグランドＧＮＤ１ｂに接続され、第２グランド端子Ｔ８は、絶縁電源５の一次側電源のグランドＧＮＤ１ａに接続される。このように回路部２内では、ＡＤ変換器７のグランドＧＮＤ１ｂと、絶縁電源５の一次側電源のグランドＧＮＤ１ａとが別々に分かれている。 In the present embodiment shown in FIG. 1, the shunt resistor 1 and the circuit unit 2 are connected by four signal lines (cable 11), and two of them are ground wirings. The circuit unit 2 is provided with a first ground terminal T7 and a second ground terminal T8 connected to each ground wiring, and the first ground terminal T7 is connected to the ground GND1b of the AD converter 7 and is connected to the second ground terminal. T8 is connected to the ground GND1a of the primary side power supply of the isolated power supply 5. In this way, in the circuit unit 2, the ground GND1b of the AD converter 7 and the ground GND1a of the primary side power supply of the isolated power supply 5 are separately separated.
　図１に示すように、シャント抵抗器１と回路部２とが接続された状態では、シャント抵抗器１、絶縁電源５、及び、絶縁アンプ６がそれぞれ電気的に接続される。このため、電源入力により、絶縁電源５の一次側電源からＡＤ変換器７に電源電圧Ｖｃｃ１が供給され、絶縁電源５の二次側電源からＤＡ変換器８及びオペアンプ９に電源電圧Ｖｃｃ２が供給される。シャント抵抗器１にて検出された電位差は、絶縁アンプ６及びオペアンプ９を経て、電流検出信号として検出される。 As shown in FIG. 1, when the shunt resistor 1 and the circuit unit 2 are connected, the shunt resistor 1, the insulated power supply 5, and the insulated amplifier 6 are electrically connected to each other. Therefore, by the power input, the power supply voltage Vcc1 is supplied to the AD converter 7 from the primary side power supply of the isolated power supply 5, and the power supply voltage Vcc2 is supplied to the DA converter 8 and the operational amplifier 9 from the secondary side power supply of the isolated power supply 5. NS. The potential difference detected by the shunt resistor 1 is detected as a current detection signal via the insulation amplifier 6 and the operational amplifier 9.
＜本実施の形態におけるコネクタの未接続状態の検知機能＞
　図２は、本実施の形態の電流検出装置１０において、シャント抵抗器１が回路部２から外れた状態を示す。図２では、各ケーブル１１と回路部２の各端子Ｔ５～Ｔ８間が外れた図とされているが、各ケーブル１１とシャント抵抗器１の各端子Ｔ１～Ｔ４間が外れていてもよい。 <Detection function of the unconnected state of the connector in this embodiment>
FIG. 2 shows a state in which the shunt resistor 1 is disconnected from the circuit unit 2 in the current detection device 10 of the present embodiment. In FIG. 2, the cable 11 and the terminals T5 to T8 of the circuit unit 2 are disconnected from each other, but the cables 11 and the terminals T1 to T4 of the shunt resistor 1 may be disconnected from each other.
　ところで、シャント抵抗器１と回路部２との間のコネクタの接続状態と未接続状態とが適切に判別される必要がある。しかしながら、図３に示す比較例の電流検出装置２０の回路構成では、コネクタの未接続状態を適切に検知することができない問題が生じた。図３、図４に示す比較例の電流検出装置２０の回路構成について、主に、本実施の形態の電流検出装置１０との相違点を中心に説明する。なお、図３、図４の比較例において、本実施の形態と同じ個所には同じ符号を付した。 By the way, it is necessary to properly determine the connected state and the unconnected state of the connector between the shunt resistor 1 and the circuit unit 2. However, in the circuit configuration of the current detection device 20 of the comparative example shown in FIG. 3, there is a problem that the unconnected state of the connector cannot be properly detected. The circuit configuration of the current detection device 20 of the comparative example shown in FIGS. 3 and 4 will be mainly described mainly focusing on the differences from the current detection device 10 of the present embodiment. In the comparative examples of FIGS. 3 and 4, the same reference numerals are given to the same parts as in the present embodiment.
　図３に示す比較例では、シャント抵抗器１と回路部２との間の信号線は３本であり、うち２本が出力配線であり、１本がグランド配線である。図３に示すように、回路部２内では、絶縁電源５の一次側電源のグランドＧＮＤ１と、絶縁アンプ６のＡＤ変換器７のグランドＧＮＤ１は、共通のグランド電位である。したがって、比較例では、第１グランド端子Ｔ７は１つのみ設けられる。 In the comparative example shown in FIG. 3, there are three signal lines between the shunt resistor 1 and the circuit unit 2, two of which are output wiring and one is ground wiring. As shown in FIG. 3, in the circuit unit 2, the ground GND1 of the primary side power supply of the isolated power supply 5 and the ground GND1 of the AD converter 7 of the isolated amplifier 6 have a common ground potential. Therefore, in the comparative example, only one first ground terminal T7 is provided.
　このため、図４に示すように、シャント抵抗器１と回路部２のコネクタが未接続状態であっても、回路部２内では、絶縁電源５の一次側電源と、絶縁アンプ６のＡＤ変換器７とは電気的に接続された状態にある。よって、電源入力により、ＡＤ変換器７には電源電圧Ｖｃｃ１が供給される。 Therefore, as shown in FIG. 4, even if the connector of the shunt resistor 1 and the circuit unit 2 is not connected, the primary side power supply of the isolated power supply 5 and the AD conversion of the isolated amplifier 6 are performed in the circuit unit 2. It is in a state of being electrically connected to the vessel 7. Therefore, the power supply voltage Vcc1 is supplied to the AD converter 7 by the power supply input.
　これにより、コネクタの未接続状態でも、図５ｂに示すように、基準電圧である電流検出信号が出力される。すなわち、ＡＤ変換器７には、第１信号出力端子Ｔ５、第２信号出力端子Ｔ６から電位差０と同じ信号が入ることで、基準電圧が出力されてしまう。例えば、出力範囲が０Ｖ～５Ｖであるとき、基準電圧は中間電位である２．５Ｖであり、シャント抵抗器１が回路部２から外れていても、基準電位としての２．５Ｖが出力される。以上により、比較例の電流検出装置２０では、コネクタの接続状態及び未接続状態を適切に判別することができない。 As a result, the current detection signal, which is the reference voltage, is output as shown in FIG. 5b even when the connector is not connected. That is, when the same signal as the potential difference 0 is input from the first signal output terminal T5 and the second signal output terminal T6 into the AD converter 7, the reference voltage is output. For example, when the output range is 0V to 5V, the reference voltage is 2.5V, which is an intermediate potential, and even if the shunt resistor 1 is out of the circuit section 2, 2.5V as the reference potential is output. .. As described above, the current detection device 20 of the comparative example cannot appropriately determine the connected state and the unconnected state of the connector.
　これに対して、本実施の形態の電流検出装置１０では、図１に示すように、シャント抵抗器１と回路部２との間の信号線は４本であり、うち２本が出力配線であり、２本がグランド配線である。これらグランド配線は、ＡＤ変換器７のグランドＧＮＤ１ｂと、絶縁電源５の一次側電源のグランドＧＮＤ１ａとを別々に分けている。このため、図２のように、シャント抵抗器１と回路部２のコネクタの未接続状態では、絶縁電源５の一次側電源と、絶縁アンプ６のＡＤ変換器７とが電気的に接続されない。したがって、電源入力によっても、ＡＤ変換器７に電源電圧Ｖｃｃ１が供給されない。一方、電源入力によって、絶縁電源５の二次電源側では、ＤＡ変換器８に電源電圧Ｖｃｃ２が供給される。 On the other hand, in the current detection device 10 of the present embodiment, as shown in FIG. 1, there are four signal lines between the shunt resistor 1 and the circuit unit 2, two of which are output wirings. Yes, two are ground wiring. These ground wirings separately separate the ground GND1b of the AD converter 7 and the ground GND1a of the primary side power supply of the isolated power supply 5. Therefore, as shown in FIG. 2, when the shunt resistor 1 and the connector of the circuit unit 2 are not connected, the primary power supply of the isolated power supply 5 and the AD converter 7 of the isolated amplifier 6 are not electrically connected. Therefore, the power supply voltage Vcc1 is not supplied to the AD converter 7 even by the power supply input. On the other hand, the power supply voltage Vcc2 is supplied to the DA converter 8 on the secondary power supply side of the isolated power supply 5 by the power supply input.
　この結果、図２に示す本実施の形態における電流検出装置１０において、シャント抵抗器１が回路部２から外れた状態にあると、ＡＤ変換器７の電源が供給されない為、ＤＡ変換器８への伝達信号はオフ状態となり、＋側もしくは－側の最大値と同等となり、図５ａの検出波形となる。図５ａでは、出力範囲が０～５Ｖのうち５Ｖ以上の異常電圧を示している。この結果、コネクタの未接続状態であることを検知することができる。コネクタの未接続状態をマイコンにて確認することができ、例えば、未接続状態の場合には、警報や光の点滅等により作業者に即座に報知することができる。 As a result, in the current detection device 10 according to the present embodiment shown in FIG. 2, if the shunt resistor 1 is in a state of being disconnected from the circuit unit 2, the power of the AD converter 7 is not supplied, and therefore the DA converter 8 is supplied. The transmission signal of is turned off, becomes equivalent to the maximum value on the + side or the-side, and becomes the detection waveform of FIG. 5a. FIG. 5a shows an abnormal voltage having an output range of 0 to 5 V and 5 V or more. As a result, it is possible to detect that the connector is not connected. The unconnected state of the connector can be confirmed by the microcomputer. For example, in the case of the unconnected state, the operator can be immediately notified by an alarm, blinking light, or the like.
　図１、図２に示す本実施の形態では、シャント抵抗器１側と、回路部２側との間にケーブル１１を配置し、シャント抵抗器１とケーブル１１の間、及び、回路部２とケーブル１１の間で、それぞれ、着脱可能な構造としたが、どちらか一方のみ着脱可能な構造であってもよい。また、ケーブル１１を用いずに、シャント抵抗器１と回路部２とが直接、端子を介して接続される構造であってもよい。 In the present embodiment shown in FIGS. 1 and 2, the cable 11 is arranged between the shunt resistor 1 side and the circuit unit 2 side, and the cable 11 is arranged between the shunt resistor 1 and the cable 11 and the circuit unit 2. Each of the cables 11 has a detachable structure, but only one of them may be detachable. Further, the shunt resistor 1 and the circuit unit 2 may be directly connected via terminals without using the cable 11.
　また、回路部２内には、ＡＤ変換器７とＤＡ変換器８との間を絶縁した絶縁アンプ６を配置することが好ましいが、抵抗器との組み合わせなどにより、ＡＤ変換器７側を高電圧領域、ＤＡ変換器８側を低電圧領域に制御できる構成であってもよい。ただし、電流検出の安定性を確保するうえで、絶縁アンプ６を用いることが好ましい。 Further, it is preferable to arrange an insulating amplifier 6 in which the AD converter 7 and the DA converter 8 are insulated from each other in the circuit unit 2, but the AD converter 7 side may be raised due to a combination with a resistor or the like. The configuration may be such that the voltage region and the DA converter 8 side can be controlled to the low voltage region. However, in order to ensure the stability of current detection, it is preferable to use the insulating amplifier 6.
　本発明によれば、シャント抵抗器と回路部とが着脱可能な電流検出装置において、コネクタの未接続状態を適切に判断することができる。これにより、接続状態の確認、接続作業を早急に行うことができ、安定した電流検出を行うことが可能になる。 According to the present invention, in a current detection device in which a shunt resistor and a circuit unit can be attached and detached, it is possible to appropriately determine the unconnected state of the connector. As a result, the connection status can be confirmed and the connection work can be performed immediately, and stable current detection can be performed.
　本出願は、２０２０年５月２０日出願の特願２０２０－０８８１００に基づく。この内容は、全てここに含めておく。 This application is based on Japanese Patent Application No. 2020-088100 filed on May 20, 2020. All this content is included here.

Claims (2)

  1. 　シャント抵抗器と、前記シャント抵抗器と着脱可能に接続される回路部と、を具備する電流検出装置であって、
    　前記回路部は、ＡＤ変換器と、前記ＡＤ変換器に電圧を供給する電源部とを、有し、
    　前記シャント抵抗器と前記回路部との間には、前記ＡＤ変換器に接続される第１グランド端子と、前記電源部に接続される第２グランド端子とが別々に設けられていることを特徴とする電流検出装置。     A current detection device including a shunt resistor and a circuit unit detachably connected to the shunt resistor.
    The circuit unit includes an AD converter and a power supply unit that supplies a voltage to the AD converter.
    A first ground terminal connected to the AD converter and a second ground terminal connected to the power supply unit are separately provided between the shunt resistor and the circuit unit. Current detector.
  2. 　前記回路部は、前記ＡＤ変換器とＤＡ変換器とが絶縁された絶縁アンプと、前記電源部としての一次側電源を有する絶縁電源と、を備えることを特徴とする請求項１に記載の電流検出装置。

          The current according to claim 1, wherein the circuit unit includes an isolated amplifier in which the AD converter and the DA converter are insulated, and an insulated power supply having a primary side power supply as the power supply unit. Detection device.
PCT/JP2021/018133 2020-05-20 2021-05-13 Current detection device WO2021235302A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0713040U (en) * 1993-08-05 1995-03-03 横河電機株式会社 Isolation amplifier
JP2003513596A (en) * 1999-10-28 2003-04-08 パワースマート，インク． Shunt resistor device that monitors the state of charge of the battery
JP2014119315A (en) * 2012-12-14 2014-06-30 Sumitomo Electric Ind Ltd Current sensor and current sensor unit
JP2017133928A (en) * 2016-01-27 2017-08-03 Koa株式会社 Shunt resistor, manufacturing method of the same, and current detector using the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0713040U (en) * 1993-08-05 1995-03-03 横河電機株式会社 Isolation amplifier
JP2003513596A (en) * 1999-10-28 2003-04-08 パワースマート，インク． Shunt resistor device that monitors the state of charge of the battery
JP2014119315A (en) * 2012-12-14 2014-06-30 Sumitomo Electric Ind Ltd Current sensor and current sensor unit
JP2017133928A (en) * 2016-01-27 2017-08-03 Koa株式会社 Shunt resistor, manufacturing method of the same, and current detector using the same

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