WO2021157222A1 - Voltage protection device and power converter - Google Patents

Voltage protection device and power converter Download PDF

Info

Publication number
WO2021157222A1
WO2021157222A1 PCT/JP2020/047356 JP2020047356W WO2021157222A1 WO 2021157222 A1 WO2021157222 A1 WO 2021157222A1 JP 2020047356 W JP2020047356 W JP 2020047356W WO 2021157222 A1 WO2021157222 A1 WO 2021157222A1
Authority
WO
WIPO (PCT)
Prior art keywords
voltage
circuit
power supply
protection
current
Prior art date
Application number
PCT/JP2020/047356
Other languages
French (fr)
Japanese (ja)
Inventor
一成 戸田
拓也 黛
Original Assignee
日立Astemo株式会社
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 日立Astemo株式会社 filed Critical 日立Astemo株式会社
Publication of WO2021157222A1 publication Critical patent/WO2021157222A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
    • H01H85/02—Details
    • H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
    • H01H85/05—Component parts thereof
    • H01H85/055—Fusible members
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
    • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
    • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
    • H02H7/122—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. dc/ac converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/20—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for electronic equipment
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • the present invention relates to a voltage protection device and a power conversion device.
  • Hybrid vehicles and electric vehicles are equipped with a large number of electric circuit parts inside the vehicle, and their operating voltages vary. Although a voltage is applied to the electric circuit component from the power supply, an overvoltage that greatly exceeds the maximum rated voltage may be applied due to a failure or the like, and it is necessary to protect the electric circuit component.
  • Patent Document 1 a varistor which is a voltage breakdown element is provided, and when an abnormal overvoltage of the AC power supply continues for a predetermined time, the varistor becomes conductive, whereby the hot pole and the neutral pole of the AC power supply are short-circuited.
  • a device is disclosed in which a fuse, which is a current cutoff element, is blown, and the blown fuse cuts off a power supply path from an AC power source.
  • Patent Document 1 has a problem that even if the voltage breakdown element conducts, the current interrupting element does not melt and the current cannot be interrupted depending on the impedance on the path.
  • the voltage protection device includes a protection target circuit to which DC power from a DC power supply is supplied, and a protection circuit arranged between the DC power supply and the protection target circuit to protect the protection target circuit from overvoltage.
  • the value is large and smaller than the predetermined withstand voltage of the protected circuit, and the impedance on the path between the voltage breakdown element and the DC power supply is between the voltage breakdown element and the protected circuit. It is smaller than the impedance on the path.
  • the voltage protection device includes a protection target circuit to which DC power from a DC power supply is supplied, and a protection circuit arranged between the DC power supply and the protection target circuit to protect the protection target circuit from overvoltage.
  • a voltage protection device including, the protection circuit includes a current cutoff element that blows and cuts off a current when a current of a predetermined value or more flows, and the current cutoff element that is electrically parallel to the protection target circuit.
  • a voltage breakdown element that is connected to the protection target circuit and conducts when a predetermined voltage or higher is applied is provided, and the breakdown voltage of the voltage breakdown element is a normal operating voltage input to the protection target circuit.
  • An inductor element that is larger and has a value smaller than a predetermined withstand voltage of the protected circuit and suppresses current fluctuation is provided on the path between the voltage breakdown element and the protected circuit.
  • the circuit to be protected can be protected by surely cutting off the current blocking element and cutting off the current.
  • FIG. 1 is a circuit configuration diagram of the power conversion device 100.
  • the power conversion device 100 converts the DC power supplied from the DC power supply 200 into AC power and drives the motor 300.
  • the power conversion device 100 includes a Y capacitor 110, a smoothing capacitor 120, an IGBT module 130, and a current sensor 140.
  • Two Y capacitors 110 are connected in series between the positive electrode bus bar BP and the negative electrode bus bar BN, and the intermediate connection point thereof is connected to the ground.
  • the smoothing capacitor 120 smoothes the current generated by ON / OFF of the switching element described later provided in the IGBT module 130, and suppresses the ripple of the DC current supplied from the DC power supply 200 to the IGBT module 130.
  • the IGBT module 130 incorporates six switching elements to form an inverter circuit. That is, the IGBT module 130 includes switching elements UH, VH, and WH that form U-phase, V-phase, and W-phase upper arm circuits, and is a switching element UL that constitutes U-phase, V-phase, and W-phase lower arm circuits. , VL, WL.
  • the motor 300 is rotationally driven by the supply of line voltage (three-phase AC voltage) from the inverter circuit.
  • the current sensor 140 detects an alternating current value supplied from the inverter circuit.
  • the power conversion device 100 further includes a motor control board 150 and a gate drive board 160.
  • the motor control board 150 receives a rotation angle signal from the motor 300 and further receives an AC current value from the current sensor 140 to generate a drive signal for driving the inverter circuit.
  • the generated drive signal is output to the IGBT module 130 via the gate drive board 160.
  • the motor control board 150 includes a voltage protection device 500 and a microcomputer (control unit) 600.
  • the voltage protection device 500 includes a protection circuit 700 and a power supply circuit 800.
  • the motor control board 150 is provided with a positive electrode terminal VP connected to the positive electrode bus bar BP and a negative electrode terminal VN connected to the negative electrode bus bar BN.
  • the protection circuit 700 is connected to the positive electrode terminal VP and the negative electrode terminal VN, and the protection circuit 700 is connected to the power supply circuit 800.
  • the details of the protection circuit 700 will be described later, but when the voltage between the positive electrode terminal VP and the negative electrode terminal VN exceeds a predetermined value, the protection circuit 700 cuts off the supply of the voltage to the power supply circuit 800.
  • the details of the power supply circuit 800 will be described later, but the voltage normally supplied to the positive electrode terminal VP and the negative electrode terminal VN is supplied to the power supply circuit 800 via the protection circuit 700. Then, based on the supplied voltage, a 12V backup power supply is generated and supplied to the microcomputer 600 via the diode D1 and the power supply IC 900. Power is also supplied to the microcomputer 600 from the 12V battery power supply 170 via the diode D2 and the power supply IC 900.
  • the power supply circuit 800 is a circuit that generates a backup power supply from a high-voltage DC power supply 200 in order to supply power to the microcomputer 600 when the 12V battery power supply 170 disappears.
  • the microcomputer 600 operates on a 12V backup power supply or a 12V battery power supply 170, and drives an inverter circuit based on a rotation angle signal input from the motor 300 and an AC current value input from the current sensor 140. To generate.
  • FIG. 2 is a circuit configuration diagram of the voltage protection device 500 according to the present embodiment.
  • the voltage protection device 500 includes a protection circuit 700 and a power supply circuit 800.
  • the protection circuit 700 is a circuit for protecting the circuit to be protected from overvoltage, that is, the power supply circuit 800 in the present embodiment.
  • the protection circuit 700 includes a current cutoff element 710, a voltage breakdown element 720, and an inductor element 730.
  • One of the current cutoff elements 710 is connected to the positive electrode terminal VP, and the other is connected to the inductor element 730.
  • the current cutoff element 710 cuts off the current by fusing when a current of a predetermined value or more flows.
  • the current cutoff element 710 is, for example, a fuse or a jumper resistor.
  • the voltage breakdown element 720 is provided between the connection point between the current cutoff element 710 and the inductor element 730 and the negative electrode terminal VN. In other words, the voltage breakdown element 720 is electrically connected in parallel with the power supply circuit 800 between the current cutoff element 710 and the power supply circuit 800 via the inductor element 730.
  • the voltage breakdown element 720 conducts when a voltage equal to or higher than a predetermined value is applied to both ends thereof.
  • the breakdown voltage of the voltage breakdown element 720 is a value larger than the normal operating voltage input to the power supply circuit 800 and smaller than the predetermined withstand voltage of the power supply circuit 800.
  • the voltage breakdown element 720 is, for example, a Zener diode, a varistor, a MOSFET, or the like.
  • the inductor element 730 is provided on the path between the voltage breakdown element 720 and the power supply circuit 800.
  • the inductor element 730 is for preventing the conduction noise generated by the switching IC 810 or the like described later from being emitted to the outside, and suppresses the fluctuation of the current on the path.
  • the inductor element 730 is, for example, EMC (Electromagnetic Compatibility) beads (ferrite beads) or the like.
  • the power supply circuit 800 includes a switching IC 810, a switching element 820, and an isolation transformer 830.
  • the switching IC 810 outputs a pulse signal to the switching element 820 connected in series with the primary winding of the isolation transformer 830, and induces a current to the secondary winding side of the isolation transformer 830.
  • a rectifier circuit 840 is provided on the secondary winding side of the isolation transformer 830, and a DC voltage of 12 V is output.
  • the switching IC 810 monitors the voltage across the resistor R1 connected in series with the switching element 820, and stops the pulse signal output to the switching element 820 when a voltage equal to or higher than a predetermined voltage is detected.
  • a voltage detection circuit 850 is provided in the primary winding of the isolation transformer 830, and the switching IC 810 monitors the voltage of the voltage detection circuit 850.
  • the problem when the protection circuit 700 is not provided will be described.
  • a plurality of electric circuit components are connected to the high voltage lines of the positive electrode bus bar BP and the negative electrode bus bar BN. Therefore, if any of the electric circuit components fails, an overvoltage may be applied between the positive electrode terminal VP and the negative electrode terminal VN due to the failure.
  • the switching element 820 of the power supply circuit 800 which is the circuit to be protected, fails due to the applied voltage and conducts, and a surge occurs on the secondary winding side of the isolation transformer 830. Therefore, the switching elements UH, VH, WH, UL, VL, and WL in the IGBT module 130 may be erroneously turned on, causing a short circuit between the positive electrode and the negative electrode.
  • the above-mentioned problem is prevented by providing the protection circuit 700.
  • an overvoltage for example, 1200V
  • the breakdown voltage of the voltage breakdown element 720 for example, 800V
  • the element 720 conducts.
  • the breakdown voltage of the voltage breakdown element 720 is smaller than the withstand voltage of the switching element 820. Due to the continuity of the voltage breakdown element 720, an overcurrent flows between the positive electrode terminal VP and the negative electrode terminal VN, and the current cutoff element 710 is blown.
  • FIG. 3 is a graph showing the relationship between the voltage breakdown element 720 and the withstand voltage of the circuit to be protected.
  • the horizontal axis is temperature and the vertical axis is voltage.
  • Graph a of FIG. 3 shows the transition of the breakdown voltage of the voltage breakdown element 720 with respect to the temperature
  • graph b shows the transition of the withstand voltage with respect to the temperature of the switching element 820 of the power supply circuit 800 which is the protection target circuit.
  • the switching element 820 includes a MOS-FET and a body diode.
  • the breakdown voltage of the voltage breakdown element 720 is lower than the withstand voltage of the switching element 820 of the power supply circuit 800 in the temperature range of ⁇ 40 ° C. to 120 ° C. Therefore, when an overvoltage is applied between the high voltage lines, the voltage breakdown element 720 causes avalanche breakdown before the circuit to be protected, and a current flows rapidly. Then, the high voltage lines are short-circuited, and the current cutoff element 710 is blown. As a result, the power supply circuit 800 is protected because the overvoltage is not applied to the power supply circuit 800, which is the circuit to be protected, and the current does not flow into the power supply circuit 800.
  • FIG. 4 is a diagram showing an example of the current cutoff element 710.
  • lands 711 are formed at both ends of the current cutoff element 710, and each land 711 is connected to the pattern 712.
  • the distance between the terminals of the current cutoff element 710 is 3.2 mm, and the distance between the lands 711 is 1.65 mm.
  • the current cutoff element 710 is a resistance element that cuts off the current by fusing when a current of a predetermined value or more flows, and the resistance element has a size of 3216.
  • an insulation distance of a predetermined length or more, for example, an insulation distance of 1.65 mm is formed at the blown portion. Since the current cutoff element 710 secures an insulation distance with respect to the applied overvoltage even after the current cutoff element 710 is blown, re-energization can be prevented even if the overvoltage is applied.
  • FIG. 5 is a circuit configuration diagram of the voltage protection device 500'according to the comparative example.
  • This comparative example is for explaining the influence of impedance on the path L1 between the voltage breakdown element 720 and the DC power supply (positive electrode terminal VP, negative electrode terminal VN).
  • the same parts as those of the voltage protection device 500 according to the present embodiment shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.
  • the arrangement position of the inductor element 730' is different from that in FIG.
  • the inductor element 730'of the protection circuit 700' is arranged between the connection point with the voltage breakdown element 720 and the current cutoff element 710.
  • a voltage breakdown element 720 is provided between the inductor element 730'and the power supply circuit 800 which is a circuit to be protected.
  • the inductor element 730' is arranged as close to the positive electrode terminal VP and the negative electrode terminal VN as possible to prevent noise from entering the circuit side or flowing out from the circuit side. Is desirable. Therefore, in general, the inductor element 730'is arranged as shown in this comparative example.
  • the impedance of the inductor element 730' rises (about 1200 ⁇ ) at the moment when the voltage breakdown element 720 conducts due to the influence of the frequency (about 48MHz) component. ), And there is a risk that the current required to blow the current blocking element 710 will not flow.
  • FIGS. 6A and 6B are graphs showing the transition of the voltage breakdown element 720 yielding in the comparative example.
  • FIG. 6B is an enlarged view of the ⁇ portion of FIG. 6A.
  • the horizontal axis of FIGS. 6A and 6B is time, and the vertical axis is voltage.
  • an inductor element 730 for preventing noise is provided between the voltage breakdown element 720 and the power supply circuit 800 which is a circuit to be protected.
  • the power supply circuit 800 which is the circuit to be protected, can be protected by reducing the influence of the frequency component f generated in the process of conducting the voltage breakdown element 720 and surely melting the current cutoff element 710. can.
  • the inductor element 730 can take EMC (Electromagnetic Compatibility) measures to prevent noise.
  • the inductor element 730 has been described as an example provided on the path between the voltage breakdown element 720 and the power supply circuit 800. However, the inductor element 730 does not necessarily have to be provided.
  • the impedance on the path L1 between the voltage breakdown element 720 and the DC power supply (positive electrode terminal VP, negative electrode terminal VN) is the voltage breakdown element 720 and the circuit to be protected. It is made smaller than the impedance on the path L2 with the power supply circuit 800. Specifically, for example, the length on the path L1 between the voltage breakdown element 720 and the positive electrode terminal VP, and the voltage breakdown element 720 and the negative electrode terminal VN, and the path between the voltage breakdown element 720 and the power supply circuit 800. Make it shorter than the length on L2. As a result, the power supply circuit 800, which is the circuit to be protected, can be protected by reducing the influence of the impedance on the path L1 and surely fusing the current cutoff element 710.
  • the impedance on the path L1 between the voltage breakdown element 720 and the DC power supply (positive terminal VP, negative terminal VN) is made smaller than the impedance on the path L2 between the voltage breakdown element 720 and the circuit to be protected.
  • the impedance element 730 may be provided on the path between the voltage breakdown element 720 and the circuit to be protected. As a result, the circuit to be protected can be protected by reducing the influence of impedance on the path L1 and more reliably fusing the current cutoff element 710.
  • the voltage protection device 500 is arranged between the power supply circuit 800 to which the DC power from the DC power supply 200 is supplied, and the DC power supply 200 and the power supply circuit 800, and is a protection circuit 700 that protects the power supply circuit 800 from overvoltage. And.
  • the protection circuit 700 is connected between a current cutoff element 710 that blows and cuts off the current when a current of a predetermined value or more flows, and a current cutoff element 710 and the power supply circuit 800 that are electrically parallel to the power supply circuit 800.
  • a voltage breakdown element 720 that conducts when a voltage equal to or higher than a predetermined value is applied is provided, and the breakdown voltage of the voltage breakdown element 720 is larger than the normal operating voltage input to the power supply circuit 800 and is determined by the power supply circuit 800.
  • the value is smaller than the withstand voltage, and the impedance on the path between the voltage breakdown element 720 and the DC power supply 200 is smaller than the impedance on the path between the voltage breakdown element 720 and the power supply circuit 800.
  • the power supply circuit 800 can be protected by surely cutting off the current cutoff element 710 and cutting off the current.
  • the voltage protection device 500 is arranged between the power supply circuit 800 to which the DC power from the DC power supply 200 is supplied, and the DC power supply 200 and the power supply circuit 800, and is a protection circuit 700 that protects the power supply circuit 800 from overvoltage. And.
  • the protection circuit 700 is connected between a current cutoff element 710 that blows and cuts off the current when a current of a predetermined value or more flows, and a current cutoff element 710 and the power supply circuit 800 that are electrically parallel to the power supply circuit 800.
  • a voltage breakdown element 720 that conducts when a voltage equal to or higher than a predetermined value is applied is provided, and the breakdown voltage of the voltage breakdown element 720 is larger than the normal operating voltage input to the power supply circuit 800 and is a predetermined value of the power supply circuit 800.
  • An inductor element 730 that suppresses current fluctuations is provided on the path between the voltage breakdown element 720 and the power supply circuit 800, which is smaller than the withstand voltage. As a result, the power supply circuit 800 can be protected by surely cutting off the current cutoff element 710 and cutting off the current.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Protection Of Static Devices (AREA)
  • Fuses (AREA)
  • Dc-Dc Converters (AREA)

Abstract

One problem to be addressed has been the inability to cut off electric current because, depending on the impedance in a path, an electric current interruption element would not be fused even when a voltage breakdown element is brought into conduction. Thus, inductor elements 730 for preventing noise are provided between a voltage breakdown element 720 and a power supply circuit 800 to be protected. With this configuration, it becomes possible to protect the power supply circuit 800 to be protected, by attenuating the impact of a frequency component f generated in the course of bringing the voltage breakdown element 720 into conduction so as to assuredly fuse the current interruption element 710. Further, it becomes possible to prevent noise by providing an EMC measure by the inductor elements 730.

Description

電圧保護装置および電力変換装置Voltage protection device and power converter
　本発明は、電圧保護装置および電力変換装置に関する。 The present invention relates to a voltage protection device and a power conversion device.
　ハイブリッド自動車や電気自動車は、車両内部に多数の電気回路部品を備え、その動作電圧も様々である。電気回路部品には電源より電圧が印加されているが、故障等により最大定格電圧を大幅に超えた過電圧が印加される場合があり、電気回路部品を保護する必要がある。 Hybrid vehicles and electric vehicles are equipped with a large number of electric circuit parts inside the vehicle, and their operating voltages vary. Although a voltage is applied to the electric circuit component from the power supply, an overvoltage that greatly exceeds the maximum rated voltage may be applied due to a failure or the like, and it is necessary to protect the electric circuit component.
　特許文献１には、電圧降伏素子であるバリスタを設け、ＡＣ電源の異常な過電圧が所定時間継続した場合、バリスタが導通状態になり、これによりＡＣ電源のホット極とニュートラル極とが短絡して電流遮断素子であるヒューズが溶断し、ヒューズの溶断により、ＡＣ電源からの電力の供給経路が遮断される装置が開示されている。 In Patent Document 1, a varistor which is a voltage breakdown element is provided, and when an abnormal overvoltage of the AC power supply continues for a predetermined time, the varistor becomes conductive, whereby the hot pole and the neutral pole of the AC power supply are short-circuited. A device is disclosed in which a fuse, which is a current cutoff element, is blown, and the blown fuse cuts off a power supply path from an AC power source.
特開２０１８－１９１４００号公報JP-A-2018-191400
　特許文献１に記載の装置では、経路上におけるインピーダンスによっては、電圧降伏素子が導通しても、電流遮断素子が溶断せず、電流を遮断することができない課題があった。 The device described in Patent Document 1 has a problem that even if the voltage breakdown element conducts, the current interrupting element does not melt and the current cannot be interrupted depending on the impedance on the path.
　本発明による電圧保護装置は、直流電源からの直流電力が供給される保護対象回路と、前記直流電源と前記保護対象回路との間に配置され、前記保護対象回路を過電圧から保護する保護回路と、を備える電圧保護装置であって、前記保護回路は、所定以上の電流が流れた時に溶断して電流を遮断する電流遮断素子と、前記保護対象回路と電気的に並列に前記電流遮断素子と保護対象回路との間に接続され、所定以上の電圧が印加された時に導通する電圧降伏素子と、を備え、前記電圧降伏素子の降伏電圧は、前記保護対象回路に入力される通常動作電圧より大きく、かつ、前記保護対象回路の所定の耐電圧より小さい値であり、前記電圧降伏素子と前記直流電源との間の経路上におけるインピーダンスは、前記電圧降伏素子と前記保護対象回路との間の経路上におけるインピーダンスよりも小さい。
　本発明による電圧保護装置は、直流電源からの直流電力が供給される保護対象回路と、前記直流電源と前記保護対象回路との間に配置され、前記保護対象回路を過電圧から保護する保護回路と、を備える電圧保護装置であって、前記保護回路は、所定以上の電流が流れた時に溶断して電流を遮断する電流遮断素子と、前記保護対象回路と電気的に並列に前記電流遮断素子と前記保護対象回路との間に接続され、所定以上の電圧が印加された時に導通する電圧降伏素子と、を備え、前記電圧降伏素子の降伏電圧は、前記保護対象回路に入力される通常動作電圧より大きく、かつ、前記保護対象回路の所定の耐電圧より小さい値であり、前記電圧降伏素子と前記保護対象回路との間の経路上に、電流の変動を抑制するインダクタ素子を備えた。 The voltage protection device according to the present invention includes a protection target circuit to which DC power from a DC power supply is supplied, and a protection circuit arranged between the DC power supply and the protection target circuit to protect the protection target circuit from overvoltage. A voltage protection device including, the protection circuit includes a current cutoff element that blows and cuts off a current when a current of a predetermined value or more flows, and the current cutoff element that is electrically parallel to the protection target circuit. It includes a voltage breakdown element that is connected to the protection target circuit and conducts when a voltage equal to or higher than a predetermined value is applied, and the breakdown voltage of the voltage breakdown element is higher than the normal operating voltage input to the protection target circuit. The value is large and smaller than the predetermined withstand voltage of the protected circuit, and the impedance on the path between the voltage breakdown element and the DC power supply is between the voltage breakdown element and the protected circuit. It is smaller than the impedance on the path.
The voltage protection device according to the present invention includes a protection target circuit to which DC power from a DC power supply is supplied, and a protection circuit arranged between the DC power supply and the protection target circuit to protect the protection target circuit from overvoltage. A voltage protection device including, the protection circuit includes a current cutoff element that blows and cuts off a current when a current of a predetermined value or more flows, and the current cutoff element that is electrically parallel to the protection target circuit. A voltage breakdown element that is connected to the protection target circuit and conducts when a predetermined voltage or higher is applied is provided, and the breakdown voltage of the voltage breakdown element is a normal operating voltage input to the protection target circuit. An inductor element that is larger and has a value smaller than a predetermined withstand voltage of the protected circuit and suppresses current fluctuation is provided on the path between the voltage breakdown element and the protected circuit.
　本発明によれば、電流遮断素子を確実に溶断して、電流を遮断することにより保護対象回路を保護することができる。 According to the present invention, the circuit to be protected can be protected by surely cutting off the current blocking element and cutting off the current.
電力変換装置の回路構成図である。It is a circuit block diagram of a power conversion device. 実施形態に係る電圧保護装置の回路構成図である。It is a circuit block diagram of the voltage protection device which concerns on embodiment. 電圧降伏素子と保護対象回路の耐電圧との関係を示すグラフである。It is a graph which shows the relationship between the voltage breakdown element and the withstand voltage of the circuit to be protected. 電流遮断素子の一例を示す図である。It is a figure which shows an example of the current cutoff element. 比較例に係る電圧保護装置の回路構成図である。It is a circuit block diagram of the voltage protection device which concerns on a comparative example. 電圧降伏素子が降伏する推移を示すグラフである。It is a graph which shows the transition that a voltage breakdown element yields. 電圧降伏素子が降伏する推移を示す拡大したグラフである。It is an enlarged graph which shows the transition that a voltage breakdown element yields.
　図１は、電力変換装置１００の回路構成図である。
　電力変換装置１００は、直流電源２００より供給される直流電力を交流電力に変換し、モータ３００を駆動する。 FIG. 1 is a circuit configuration diagram of the power conversion device 100.
The power conversion device 100 converts the DC power supplied from the DC power supply 200 into AC power and drives the motor 300.
　電力変換装置１００は、Ｙキャパシタ１１０、平滑キャパシタ１２０、ＩＧＢＴモジュール１３０、および電流センサ１４０を備える。
　Ｙキャパシタ１１０は、正極バスバーＢＰと負極バスバーＢＮとの間に２個直列に接続され、その中間接続点はグランドと接続される。 The power conversion device 100 includes a Y capacitor 110, a smoothing capacitor 120, an IGBT module 130, and a current sensor 140.
Two Y capacitors 110 are connected in series between the positive electrode bus bar BP and the negative electrode bus bar BN, and the intermediate connection point thereof is connected to the ground.
　平滑キャパシタ１２０は、ＩＧＢＴモジュール１３０内に設けられた後述のスイッチング素子のＯＮ/ＯＦＦによって生じる電流を平滑化し、直流電源２００からＩＧＢＴモジュール１３０へ供給される直流電流のリップルを抑制する。 The smoothing capacitor 120 smoothes the current generated by ON / OFF of the switching element described later provided in the IGBT module 130, and suppresses the ripple of the DC current supplied from the DC power supply 200 to the IGBT module 130.
　ＩＧＢＴモジュール１３０は、６個のスイッチング素子を内蔵し、インバータ回路を構成する。すなわち、ＩＧＢＴモジュール１３０は、Ｕ相、Ｖ相、Ｗ相の上アーム回路を構成するスイッチング素子ＵＨ、ＶＨ、ＷＨを備え、Ｕ相、Ｖ相、Ｗ相の下アーム回路を構成するスイッチング素子ＵＬ、ＶＬ、ＷＬを備える。 The IGBT module 130 incorporates six switching elements to form an inverter circuit. That is, the IGBT module 130 includes switching elements UH, VH, and WH that form U-phase, V-phase, and W-phase upper arm circuits, and is a switching element UL that constitutes U-phase, V-phase, and W-phase lower arm circuits. , VL, WL.
　モータ３００は、インバータ回路からの線間電圧（三相交流電圧）の供給により回転駆動される。電流センサ１４０はインバータ回路から供給される交流電流値を検出する。 The motor 300 is rotationally driven by the supply of line voltage (three-phase AC voltage) from the inverter circuit. The current sensor 140 detects an alternating current value supplied from the inverter circuit.
　電力変換装置１００は、さらに、モータ制御基板１５０、ゲートドライブ基板１６０を備える。モータ制御基板１５０は、モータ３００から回転角度信号を受けて、さらに電流センサ１４０から交流電流値を受けて、インバータ回路を駆動する駆動信号を生成する。
生成した駆動信号は、ゲートドライブ基板１６０を介してＩＧＢＴモジュール１３０へ出力される。 The power conversion device 100 further includes a motor control board 150 and a gate drive board 160. The motor control board 150 receives a rotation angle signal from the motor 300 and further receives an AC current value from the current sensor 140 to generate a drive signal for driving the inverter circuit.
The generated drive signal is output to the IGBT module 130 via the gate drive board 160.
　モータ制御基板１５０は、電圧保護装置５００、マイコン（制御部）６００を備える。
電圧保護装置５００は、保護回路７００と電源回路８００を備える。モータ制御基板１５０には、正極バスバーＢＰと接続される正極端子ＶＰ、および負極バスバーＢＮに接続される負極端子ＶＮが設けられる。 The motor control board 150 includes a voltage protection device 500 and a microcomputer (control unit) 600.
The voltage protection device 500 includes a protection circuit 700 and a power supply circuit 800. The motor control board 150 is provided with a positive electrode terminal VP connected to the positive electrode bus bar BP and a negative electrode terminal VN connected to the negative electrode bus bar BN.
　保護回路７００は、正極端子ＶＰおよび負極端子ＶＮが接続され、保護回路７００は電源回路８００に接続される。保護回路７００は、その詳細は後述するが、正極端子ＶＰおよび負極端子ＶＮ間の電圧が所定値を超えた場合は、電源回路８００への電圧の供給を遮断する。 The protection circuit 700 is connected to the positive electrode terminal VP and the negative electrode terminal VN, and the protection circuit 700 is connected to the power supply circuit 800. The details of the protection circuit 700 will be described later, but when the voltage between the positive electrode terminal VP and the negative electrode terminal VN exceeds a predetermined value, the protection circuit 700 cuts off the supply of the voltage to the power supply circuit 800.
　電源回路８００には、その詳細は後述するが、通常は正極端子ＶＰおよび負極端子ＶＮに供給されている電圧が保護回路７００を介して供給されている。そして、供給された電圧を基に、１２Ｖのバックアップ用電源を生成し、ダイオードＤ１と電源ＩＣ９００を介してマイコン６００へ供給する。マイコン６００には、１２Ｖのバッテリ電源１７０からもダイオードＤ２と電源ＩＣ９００を介して電源が供給されている。電源回路８００は、１２Ｖのバッテリ電源１７０が消失した場合に、マイコン６００へ電源を供給するために、高電圧の直流電源２００からバックアップ用電源を生成する回路である。 The details of the power supply circuit 800 will be described later, but the voltage normally supplied to the positive electrode terminal VP and the negative electrode terminal VN is supplied to the power supply circuit 800 via the protection circuit 700. Then, based on the supplied voltage, a 12V backup power supply is generated and supplied to the microcomputer 600 via the diode D1 and the power supply IC 900. Power is also supplied to the microcomputer 600 from the 12V battery power supply 170 via the diode D2 and the power supply IC 900. The power supply circuit 800 is a circuit that generates a backup power supply from a high-voltage DC power supply 200 in order to supply power to the microcomputer 600 when the 12V battery power supply 170 disappears.
　マイコン６００は、１２Ｖのバックアップ用電源または１２Ｖのバッテリ電源１７０で動作し、モータ３００より入力される回転角度信号や電流センサ１４０から入力される交流電流値に基づいて、インバータ回路を駆動する駆動信号を生成する。 The microcomputer 600 operates on a 12V backup power supply or a 12V battery power supply 170, and drives an inverter circuit based on a rotation angle signal input from the motor 300 and an AC current value input from the current sensor 140. To generate.
　図２は、本実施形態に係る電圧保護装置５００の回路構成図である。
　図２に示すように、電圧保護装置５００は、保護回路７００と電源回路８００を備える。保護回路７００は、過電圧から保護対象回路、本実施形態では電源回路８００を保護するための回路である。保護回路７００は、電流遮断素子７１０、電圧降伏素子７２０、インダクタ素子７３０を備える。電流遮断素子７１０は一方を正極端子ＶＰに、他方をインダクタ素子７３０に接続される。電流遮断素子７１０は、所定以上の電流が流れた時に溶断して電流を遮断する。電流遮断素子７１０は、例えばヒューズやジャンパ抵抗などである。 FIG. 2 is a circuit configuration diagram of the voltage protection device 500 according to the present embodiment.
As shown in FIG. 2, the voltage protection device 500 includes a protection circuit 700 and a power supply circuit 800. The protection circuit 700 is a circuit for protecting the circuit to be protected from overvoltage, that is, the power supply circuit 800 in the present embodiment. The protection circuit 700 includes a current cutoff element 710, a voltage breakdown element 720, and an inductor element 730. One of the current cutoff elements 710 is connected to the positive electrode terminal VP, and the other is connected to the inductor element 730. The current cutoff element 710 cuts off the current by fusing when a current of a predetermined value or more flows. The current cutoff element 710 is, for example, a fuse or a jumper resistor.
　電圧降伏素子７２０は、電流遮断素子７１０とインダクタ素子７３０との接続点と負極端子ＶＮとの間に設けられる。換言すれば、電圧降伏素子７２０は、電源回路８００と電気的に並列に、電流遮断素子７１０と電源回路８００との間であって、インダクタ素子７３０を介して接続される。電圧降伏素子７２０は、その両端に所定以上の電圧が印加された時に導通する。電圧降伏素子７２０の降伏電圧は、電源回路８００に入力される通常動作電圧より大きく、かつ、電源回路８００の所定の耐電圧より小さい値である。電圧降伏素子７２０は、例えば、ツェナーダイオード、バリスタ、ＭＯＳＦＥＴなどである。 The voltage breakdown element 720 is provided between the connection point between the current cutoff element 710 and the inductor element 730 and the negative electrode terminal VN. In other words, the voltage breakdown element 720 is electrically connected in parallel with the power supply circuit 800 between the current cutoff element 710 and the power supply circuit 800 via the inductor element 730. The voltage breakdown element 720 conducts when a voltage equal to or higher than a predetermined value is applied to both ends thereof. The breakdown voltage of the voltage breakdown element 720 is a value larger than the normal operating voltage input to the power supply circuit 800 and smaller than the predetermined withstand voltage of the power supply circuit 800. The voltage breakdown element 720 is, for example, a Zener diode, a varistor, a MOSFET, or the like.
　インダクタ素子７３０は、電圧降伏素子７２０と電源回路８００との間の経路上に設けられる。インダクタ素子７３０は、後述のスイッチングＩＣ８１０等により発生する伝導ノイズを外部へ放出しないようにするためであり、経路上の電流の変動を抑制する。インダクタ素子７３０は、例えばＥＭＣ（Electromagnetic Compatibility）ビーズ（フェライトビーズ）などである。 The inductor element 730 is provided on the path between the voltage breakdown element 720 and the power supply circuit 800. The inductor element 730 is for preventing the conduction noise generated by the switching IC 810 or the like described later from being emitted to the outside, and suppresses the fluctuation of the current on the path. The inductor element 730 is, for example, EMC (Electromagnetic Compatibility) beads (ferrite beads) or the like.
　電源回路８００は、スイッチングＩＣ８１０とスイッチング素子８２０と絶縁トランス８３０を備える。スイッチングＩＣ８１０は、絶縁トランス８３０の一次巻線に直列に接続されたスイッチング素子８２０にパルス信号を出力し、絶縁トランス８３０の二次巻線側に電流を誘導する。絶縁トランス８３０の二次巻線側には整流回路８４０が備えられ、１２Ｖの直流電圧が出力される。スイッチングＩＣ８１０は、スイッチング素子８２０に直列に接続された抵抗Ｒ１の両端の電圧をモニタしており、所定の電圧以上の電圧が検出された場合は、スイッチング素子８２０へ出力するパルス信号を停止する。絶縁トランス８３０の一次巻線には、電圧検出回路８５０が設けられており、スイッチングＩＣ８１０は、電圧検出回路８５０の電圧を監視している。 The power supply circuit 800 includes a switching IC 810, a switching element 820, and an isolation transformer 830. The switching IC 810 outputs a pulse signal to the switching element 820 connected in series with the primary winding of the isolation transformer 830, and induces a current to the secondary winding side of the isolation transformer 830. A rectifier circuit 840 is provided on the secondary winding side of the isolation transformer 830, and a DC voltage of 12 V is output. The switching IC 810 monitors the voltage across the resistor R1 connected in series with the switching element 820, and stops the pulse signal output to the switching element 820 when a voltage equal to or higher than a predetermined voltage is detected. A voltage detection circuit 850 is provided in the primary winding of the isolation transformer 830, and the switching IC 810 monitors the voltage of the voltage detection circuit 850.
　ここで、保護回路７００を設けなかった場合の問題について説明する。正極バスバーＢＰと負極バスバーＢＮの高電圧ラインには、ＩＧＢＴモジュール１３０以外にも複数の電気回路部品が接続されている。そのため、もし、何れかの電気回路部品が故障し、その影響により、過電圧が正極端子ＶＰと負極端子ＶＮの間に印加される場合がある。この場合には、保護対象回路である電源回路８００のスイッチング素子８２０が印加電圧により故障して導通し、絶縁トランス８３０の二次巻線側にサージが発生する。このため、ＩＧＢＴモジュール１３０内のスイッチング素子ＵＨ、ＶＨ、ＷＨ、ＵＬ、ＶＬ、ＷＬが誤ってＯＮになり、正極と負極の短絡ショートを起こす虞がある。 Here, the problem when the protection circuit 700 is not provided will be described. In addition to the IGBT module 130, a plurality of electric circuit components are connected to the high voltage lines of the positive electrode bus bar BP and the negative electrode bus bar BN. Therefore, if any of the electric circuit components fails, an overvoltage may be applied between the positive electrode terminal VP and the negative electrode terminal VN due to the failure. In this case, the switching element 820 of the power supply circuit 800, which is the circuit to be protected, fails due to the applied voltage and conducts, and a surge occurs on the secondary winding side of the isolation transformer 830. Therefore, the switching elements UH, VH, WH, UL, VL, and WL in the IGBT module 130 may be erroneously turned on, causing a short circuit between the positive electrode and the negative electrode.
　本実施形態では保護回路７００を設けることにより、前述の問題を防止する。何らかの原因により、高電圧ライン間にＩＧＢＴモジュール１３０の最大定格電圧を大幅に超えた過電圧（例えば１２００Ｖ）が印加された場合に、電圧降伏素子７２０の降伏電圧(例えば８００Ｖ)を超えるため、電圧降伏素子７２０が導通する。電圧降伏素子７２０の降伏電圧は、スイッチング素子８２０の耐電圧より小さい値である。電圧降伏素子７２０の導通により、正極端子ＶＰと負極端子ＶＮの間に過電流が流れ、電流遮断素子７１０が溶断する。なお、電圧降伏素子７２０と直流電源（正極端子ＶＰ、負極端子ＶＮ）との間の経路Ｌ１上におけるインピーダンスと、電圧降伏素子７２０と保護対象回路との間の経路Ｌ２上におけるインピーダンスの影響については後述する。 In this embodiment, the above-mentioned problem is prevented by providing the protection circuit 700. When an overvoltage (for example, 1200V) that greatly exceeds the maximum rated voltage of the IGBT module 130 is applied between the high voltage lines for some reason, the breakdown voltage of the voltage breakdown element 720 (for example, 800V) is exceeded, so that the voltage breakdown occurs. The element 720 conducts. The breakdown voltage of the voltage breakdown element 720 is smaller than the withstand voltage of the switching element 820. Due to the continuity of the voltage breakdown element 720, an overcurrent flows between the positive electrode terminal VP and the negative electrode terminal VN, and the current cutoff element 710 is blown. Regarding the influence of the impedance on the path L1 between the voltage breakdown element 720 and the DC power supply (positive electrode terminal VP, negative electrode terminal VN) and the impedance on the path L2 between the voltage breakdown element 720 and the circuit to be protected. It will be described later.
　図３は、電圧降伏素子７２０と保護対象回路の耐電圧との関係を示すグラフである。横軸は温度であり、縦軸は電圧である。
　図３のグラフａは電圧降伏素子７２０の降伏電圧の温度に対する推移を表し、グラフｂは保護対象回路である電源回路８００のスイッチング素子８２０の温度に対する耐電圧の推移を表わす。スイッチング素子８２０は、ＭＯＳ－ＦＥＴとボディダイオードよりなる。 FIG. 3 is a graph showing the relationship between the voltage breakdown element 720 and the withstand voltage of the circuit to be protected. The horizontal axis is temperature and the vertical axis is voltage.
Graph a of FIG. 3 shows the transition of the breakdown voltage of the voltage breakdown element 720 with respect to the temperature, and graph b shows the transition of the withstand voltage with respect to the temperature of the switching element 820 of the power supply circuit 800 which is the protection target circuit. The switching element 820 includes a MOS-FET and a body diode.
　図３のグラフａ、グラフｂに示すように、電圧降伏素子７２０の降伏電圧は、温度範囲－４０℃～１２０℃において、電源回路８００のスイッチング素子８２０の耐電圧より低い。したがって、高電圧ライン間に過電圧が印加された場合に、保護対象回路よりも先に電圧降伏素子７２０がなだれ降伏を起こして急激に電流が流れる。そして、高電圧ライン間は短絡して、電流遮断素子７１０が溶断する。その結果、保護対象回路である電源回路８００に過電圧が印加されず、電流が流れ込まないため、電源回路８００が保護される。 As shown in graphs a and b of FIG. 3, the breakdown voltage of the voltage breakdown element 720 is lower than the withstand voltage of the switching element 820 of the power supply circuit 800 in the temperature range of −40 ° C. to 120 ° C. Therefore, when an overvoltage is applied between the high voltage lines, the voltage breakdown element 720 causes avalanche breakdown before the circuit to be protected, and a current flows rapidly. Then, the high voltage lines are short-circuited, and the current cutoff element 710 is blown. As a result, the power supply circuit 800 is protected because the overvoltage is not applied to the power supply circuit 800, which is the circuit to be protected, and the current does not flow into the power supply circuit 800.
　図４は電流遮断素子７１０の一例を示す図である。
　図４に示すように、電流遮断素子７１０の両端にランド７１１が形成され、各ランド７１１はパターン７１２へ接続されている。電流遮断素子７１０の端子間距離は３．２ｍｍであり、ランド７１１間距離は１．６５ｍｍである。すなわち、電流遮断素子７１０は、所定値以上の電流が流れた場合に溶断することで電流を遮断する抵抗素子であり、抵抗素子は３２１６サイズである。そして、電流遮断素子７１０は、溶断された場合に溶断箇所が所定以上の絶縁距離、例えば絶縁距離１．６５ｍｍが形成される。電流遮断素子７１０は、電流遮断素子７１０の溶断後も、印加される過電圧に対する絶縁距離を確保しているため、過電圧が印加されても、再通電を防ぐ事ができる。 FIG. 4 is a diagram showing an example of the current cutoff element 710.
As shown in FIG. 4, lands 711 are formed at both ends of the current cutoff element 710, and each land 711 is connected to the pattern 712. The distance between the terminals of the current cutoff element 710 is 3.2 mm, and the distance between the lands 711 is 1.65 mm. That is, the current cutoff element 710 is a resistance element that cuts off the current by fusing when a current of a predetermined value or more flows, and the resistance element has a size of 3216. Then, when the current cutoff element 710 is blown, an insulation distance of a predetermined length or more, for example, an insulation distance of 1.65 mm is formed at the blown portion. Since the current cutoff element 710 secures an insulation distance with respect to the applied overvoltage even after the current cutoff element 710 is blown, re-energization can be prevented even if the overvoltage is applied.
　図５は、比較例に係る電圧保護装置５００’の回路構成図である。この比較例は、電圧降伏素子７２０と直流電源（正極端子ＶＰ、負極端子ＶＮ）との間の経路Ｌ１上におけるインピーダンスの影響を説明するためのものである。図２に示した本実施形態に係る電圧保護装置５００と同一の個所には同一の符号を附してその説明を省略する。図５では、インダクタ素子７３０’の配置位置が図２とは異なる。 FIG. 5 is a circuit configuration diagram of the voltage protection device 500'according to the comparative example. This comparative example is for explaining the influence of impedance on the path L1 between the voltage breakdown element 720 and the DC power supply (positive electrode terminal VP, negative electrode terminal VN). The same parts as those of the voltage protection device 500 according to the present embodiment shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 5, the arrangement position of the inductor element 730'is different from that in FIG.
　図５に示す比較例では、保護回路７００’のインダクタ素子７３０’は、電圧降伏素子７２０との接続点と電流遮断素子７１０との間に配置される。換言すれば、インダクタ素子７３０’と保護対象回路である電源回路８００の間に電圧降伏素子７２０を設ける。 In the comparative example shown in FIG. 5, the inductor element 730'of the protection circuit 700'is arranged between the connection point with the voltage breakdown element 720 and the current cutoff element 710. In other words, a voltage breakdown element 720 is provided between the inductor element 730'and the power supply circuit 800 which is a circuit to be protected.
　ＥＭＣ（Electromagnetic Compatibility）対策等では、インダクタ素子７３０’は、可能な限り正極端子ＶＰ、負極端子ＶＮの近くに配置して、ノイズが回路側に侵入する、または回路側から流出するのを防止することが望ましい。したがって、一般的には、インダクタ素子７３０’は、この比較例に示すように配置される。 In EMC (Electromagnetic Compatibility) measures, etc., the inductor element 730'is arranged as close to the positive electrode terminal VP and the negative electrode terminal VN as possible to prevent noise from entering the circuit side or flowing out from the circuit side. Is desirable. Therefore, in general, the inductor element 730'is arranged as shown in this comparative example.
　インダクタ素子７３０’と電源回路８００の間に電圧降伏素子７２０を設けた場合、電圧降伏素子７２０が導通した瞬間、周波数(約４８ＭＨｚ)成分の影響により、インダクタ素子７３０’のインピーダンスが上昇(約１２００Ω)し、電流遮断素子７１０を溶断するのに必要な電流が流れなくなる虞がある。 When the voltage breakdown element 720 is provided between the inductor element 730'and the power supply circuit 800, the impedance of the inductor element 730' rises (about 1200Ω) at the moment when the voltage breakdown element 720 conducts due to the influence of the frequency (about 48MHz) component. ), And there is a risk that the current required to blow the current blocking element 710 will not flow.
　図６Ａ、図６Ｂは、比較例において、電圧降伏素子７２０が降伏する推移を示すグラフである。図６Ｂは、図６Ａのα部の拡大図である。図６Ａ、図６Ｂの横軸は時間、縦軸は電圧である。 6A and 6B are graphs showing the transition of the voltage breakdown element 720 yielding in the comparative example. FIG. 6B is an enlarged view of the α portion of FIG. 6A. The horizontal axis of FIGS. 6A and 6B is time, and the vertical axis is voltage.
　図５に示す比較例に係る電圧保護装置５００’において、図６Ａに示すように、時間ｔ１で過電圧の印加が開始されたとする。正極端子ＶＰと負極端子ＶＮとの間の電圧は急激に上昇し、時刻ｔ２において、電圧降伏素子７２０が導通する。その後、正極端子ＶＰと負極端子ＶＮとの間には印加された電圧が掛かっている。図６Ａのα部の拡大図である図６Ｂに示すように、電圧降伏素子７２０が導通する過程において、周波数成分ｆが発生する。この周波数成分ｆは、インダクタ素子７３０’に作用し、インダクタ素子７３０’のインピーダンスが上昇(約１２００Ω)する。その結果、電流遮断素子７１０を溶断するために必要な電流が流れなくなる虞がある。 In the voltage protection device 500'according to the comparative example shown in FIG. 5, it is assumed that the application of the overvoltage is started at the time t1 as shown in FIG. 6A. The voltage between the positive electrode terminal VP and the negative electrode terminal VN rises sharply, and the voltage yield element 720 conducts at time t2. After that, an applied voltage is applied between the positive electrode terminal VP and the negative electrode terminal VN. As shown in FIG. 6B, which is an enlarged view of the α portion of FIG. 6A, the frequency component f is generated in the process of conducting the voltage breakdown element 720. This frequency component f acts on the inductor element 730', and the impedance of the inductor element 730' rises (about 1200Ω). As a result, there is a risk that the current required to blow the current blocking element 710 will not flow.
　これに対して、本実施形態では、図２に示すように、ノイズを防止するためのインダクタ素子７３０を電圧降伏素子７２０と保護対象回路である電源回路８００との間に設ける。これにより、電圧降伏素子７２０が導通する過程において、発生する周波数成分ｆの影響を少なくして、電流遮断素子７１０を確実に溶断することにより、保護対象回路である電源回路８００を保護することができる。さらに、インダクタ素子７３０によりＥＭＣ（Electromagnetic Compatibility）対策を施し、ノイズを防止することができる。 On the other hand, in the present embodiment, as shown in FIG. 2, an inductor element 730 for preventing noise is provided between the voltage breakdown element 720 and the power supply circuit 800 which is a circuit to be protected. As a result, the power supply circuit 800, which is the circuit to be protected, can be protected by reducing the influence of the frequency component f generated in the process of conducting the voltage breakdown element 720 and surely melting the current cutoff element 710. can. Further, the inductor element 730 can take EMC (Electromagnetic Compatibility) measures to prevent noise.
　図２に示す例では、インダクタ素子７３０は、電圧降伏素子７２０と電源回路８００との間の経路上に設けた例で説明した。しかし、インダクタ素子７３０は、必ずしも設ける必要はない。 In the example shown in FIG. 2, the inductor element 730 has been described as an example provided on the path between the voltage breakdown element 720 and the power supply circuit 800. However, the inductor element 730 does not necessarily have to be provided.
　インダクタ素子７３０を、設けない場合であっても、電圧降伏素子７２０と直流電源（正極端子ＶＰ、負極端子ＶＮ）との間の経路Ｌ１上におけるインピーダンスを、電圧降伏素子７２０と保護対象回路である電源回路８００との間の経路Ｌ２上におけるインピーダンスよりも小さくする。具体的には、例えば、電圧降伏素子７２０と正極端子ＶＰ、および電圧降伏素子７２０と負極端子ＶＮとの間の経路Ｌ１上の長さを、電圧降伏素子７２０と電源回路８００との間の経路Ｌ２上の長さよりも短くする。これにより、経路Ｌ１上におけるインピーダンスの影響を少なくして、電流遮断素子７１０を確実に溶断することにより、保護対象回路である電源回路８００を保護することができる。 Even if the inductor element 730 is not provided, the impedance on the path L1 between the voltage breakdown element 720 and the DC power supply (positive electrode terminal VP, negative electrode terminal VN) is the voltage breakdown element 720 and the circuit to be protected. It is made smaller than the impedance on the path L2 with the power supply circuit 800. Specifically, for example, the length on the path L1 between the voltage breakdown element 720 and the positive electrode terminal VP, and the voltage breakdown element 720 and the negative electrode terminal VN, and the path between the voltage breakdown element 720 and the power supply circuit 800. Make it shorter than the length on L2. As a result, the power supply circuit 800, which is the circuit to be protected, can be protected by reducing the influence of the impedance on the path L1 and surely fusing the current cutoff element 710.
　なお、電圧降伏素子７２０と直流電源（正極端子ＶＰ、負極端子ＶＮ）との間の経路Ｌ１上におけるインピーダンスを、電圧降伏素子７２０と保護対象回路との間の経路Ｌ２上におけるインピーダンスよりも小さくして、且つ、電圧降伏素子７２０と保護対象回路との間の経路上にインダクタ素子７３０を設けてもよい。これにより、経路Ｌ１上におけるインピーダンスの影響をより少なくして、電流遮断素子７１０をより確実に溶断することにより、保護対象回路を保護することができる。 The impedance on the path L1 between the voltage breakdown element 720 and the DC power supply (positive terminal VP, negative terminal VN) is made smaller than the impedance on the path L2 between the voltage breakdown element 720 and the circuit to be protected. Moreover, the impedance element 730 may be provided on the path between the voltage breakdown element 720 and the circuit to be protected. As a result, the circuit to be protected can be protected by reducing the influence of impedance on the path L1 and more reliably fusing the current cutoff element 710.
　以上説明した実施形態によれば、次の作用効果が得られる。
（１）電圧保護装置５００は、直流電源２００からの直流電力が供給される電源回路８００と、直流電源２００と電源回路８００との間に配置され、電源回路８００を過電圧から保護する保護回路７００と、を備える。保護回路７００は、所定以上の電流が流れた時に溶断して電流を遮断する電流遮断素子７１０と、電源回路８００と電気的に並列に電流遮断素子７１０と電源回路８００との間に接続され、所定以上の電圧が印加された時に導通する電圧降伏素子７２０と、を備え、電圧降伏素子７２０の降伏電圧は、電源回路８００に入力される通常動作電圧より大きく、かつ、電源回路８００の所定の耐電圧より小さい値であり、電圧降伏素子７２０と直流電源２００との間の経路上におけるインピーダンスは、電圧降伏素子７２０と電源回路８００との間の経路上におけるインピーダンスよりも小さい。これにより、電流遮断素子７１０を確実に溶断して、電流を遮断することにより電源回路８００を保護することができる。 According to the embodiment described above, the following effects can be obtained.
(1) The voltage protection device 500 is arranged between the power supply circuit 800 to which the DC power from the DC power supply 200 is supplied, and the DC power supply 200 and the power supply circuit 800, and is a protection circuit 700 that protects the power supply circuit 800 from overvoltage. And. The protection circuit 700 is connected between a current cutoff element 710 that blows and cuts off the current when a current of a predetermined value or more flows, and a current cutoff element 710 and the power supply circuit 800 that are electrically parallel to the power supply circuit 800. A voltage breakdown element 720 that conducts when a voltage equal to or higher than a predetermined value is applied is provided, and the breakdown voltage of the voltage breakdown element 720 is larger than the normal operating voltage input to the power supply circuit 800 and is determined by the power supply circuit 800. The value is smaller than the withstand voltage, and the impedance on the path between the voltage breakdown element 720 and the DC power supply 200 is smaller than the impedance on the path between the voltage breakdown element 720 and the power supply circuit 800. As a result, the power supply circuit 800 can be protected by surely cutting off the current cutoff element 710 and cutting off the current.
（２）電圧保護装置５００は、直流電源２００からの直流電力が供給される電源回路８００と、直流電源２００と電源回路８００との間に配置され、電源回路８００を過電圧から保護する保護回路７００と、を備える。保護回路７００は、所定以上の電流が流れた時に溶断して電流を遮断する電流遮断素子７１０と、電源回路８００と電気的に並列に電流遮断素子７１０と電源回路８００との間に接続され、所定以上の電圧が印加された時に導通する電圧降伏素子７２０と、を備え、電圧降伏素子７２０の降伏電圧は、電源回路８００に入力される通常動作電圧より大きく、かつ、電源回路８００の所定の耐電圧より小さい値であり、電圧降伏素子７２０と電源回路８００との間の経路上に、電流の変動を抑制するインダクタ素子７３０を備えた。これにより、電流遮断素子７１０を確実に溶断して、電流を遮断することにより電源回路８００を保護することができる。 (2) The voltage protection device 500 is arranged between the power supply circuit 800 to which the DC power from the DC power supply 200 is supplied, and the DC power supply 200 and the power supply circuit 800, and is a protection circuit 700 that protects the power supply circuit 800 from overvoltage. And. The protection circuit 700 is connected between a current cutoff element 710 that blows and cuts off the current when a current of a predetermined value or more flows, and a current cutoff element 710 and the power supply circuit 800 that are electrically parallel to the power supply circuit 800. A voltage breakdown element 720 that conducts when a voltage equal to or higher than a predetermined value is applied is provided, and the breakdown voltage of the voltage breakdown element 720 is larger than the normal operating voltage input to the power supply circuit 800 and is a predetermined value of the power supply circuit 800. An inductor element 730 that suppresses current fluctuations is provided on the path between the voltage breakdown element 720 and the power supply circuit 800, which is smaller than the withstand voltage. As a result, the power supply circuit 800 can be protected by surely cutting off the current cutoff element 710 and cutting off the current.
　本発明は、上記の実施形態に限定されるものではなく、本発明の特徴を損なわない限り、本発明の技術思想の範囲内で考えられるその他の形態についても、本発明の範囲内に含まれる。 The present invention is not limited to the above-described embodiment, and other embodiments that can be considered within the scope of the technical idea of the present invention are also included within the scope of the present invention as long as the features of the present invention are not impaired. ..
　１００・・・電力変換装置、１１０・・・Ｙキャパシタ、１２０・・・平滑キャパシタ、１３０・・・ＩＧＢＴモジュール、１４０・・・電流センサ、１５０・・・モータ制御基板、１６０・・・ゲートドライブ基板、１７０・・・バッテリ電源、２００・・・直流電源、３００・・・モータ、５００・・・電圧保護装置、６００・・・マイコン、７００・・・保護回路、７１０・・・電流遮断素子、７１１・・・ランド、７１２・・・パターン、７２０・・・電圧降伏素子、７３０・・・インダクタ素子、８００・・・電源回路、８１０・・・スイッチングＩＣ、８２０・・・スイッチング素子、８３０・・・絶縁トランス、８４０・・・整流回路、８５０・・・電圧検出回路、ＢＰ・・・正極バスバー、ＢＮ・・・負極バスバー、ＶＰ・・・正極端子、ＶＮ・・・負極端子、ＵＨ、ＶＨ、ＷＨ、ＵＬ、ＶＬ、ＷＬ・・・スイッチング素子、９００・・・電源ＩＣ。 100 ... Power converter, 110 ... Y capacitor, 120 ... Smoothing capacitor, 130 ... IGBT module, 140 ... Current sensor, 150 ... Motor control board, 160 ... Gate drive Board, 170 ... Battery power supply, 200 ... DC power supply, 300 ... Motor, 500 ... Voltage protection device, 600 ... Microcomputer, 700 ... Protection circuit, 710 ... Current interruption element , 711 ... land, 712 ... pattern, 720 ... voltage breakdown element, 730 ... inductor element, 800 ... power supply circuit, 810 ... switching IC, 820 ... switching element, 830 ... Insulated transformer, 840 ... Rectifier circuit, 850 ... Voltage detection circuit, BP ... Positive bus bar, BN ... Negative negative bus bar, VP ... Positive terminal, VN ... Negative terminal, UH , VH, WH, UL, VL, WL ... Switching element, 900 ... Power supply IC.

Claims (9)

  1. 　直流電源からの直流電力が供給される保護対象回路と、
    　前記直流電源と前記保護対象回路との間に配置され、前記保護対象回路を過電圧から保護する保護回路と、を備える電圧保護装置であって、
    　前記保護回路は、所定以上の電流が流れた時に溶断して電流を遮断する電流遮断素子と、前記保護対象回路と電気的に並列に前記電流遮断素子と前記保護対象回路との間に接続され、所定以上の電圧が印加された時に導通する電圧降伏素子と、を備え、
    　前記電圧降伏素子の降伏電圧は、前記保護対象回路に入力される通常動作電圧より大きく、かつ、前記保護対象回路の所定の耐電圧より小さい値であり、
    　前記電圧降伏素子と前記直流電源との間の経路上におけるインピーダンスは、前記電圧降伏素子と前記保護対象回路との間の経路上におけるインピーダンスよりも小さい電圧保護装置。     A protected circuit to which DC power is supplied from a DC power supply, and
    A voltage protection device including a protection circuit arranged between the DC power supply and the protection target circuit and protecting the protection target circuit from overvoltage.
    The protection circuit is connected between a current cutoff element that blows and cuts off the current when a current of a predetermined value or more flows, and the current cutoff element and the protection target circuit in electrical parallel with the protection target circuit. A voltage breakdown element that conducts when a voltage higher than a predetermined value is applied.
    The breakdown voltage of the voltage breakdown element is a value larger than the normal operating voltage input to the protection target circuit and smaller than a predetermined withstand voltage of the protection target circuit.
    A voltage protection device in which the impedance on the path between the voltage breakdown element and the DC power supply is smaller than the impedance on the path between the voltage breakdown element and the protection target circuit.
  2. 　請求項１記載の電圧保護装置において、
    　前記保護回路には、前記直流電源から正極端子、負極端子を経て前記直流電力が供給され、
    　前記電圧降伏素子と前記正極端子、および前記電圧降伏素子と前記負極端子との間の経路上の長さは、前記電圧降伏素子と前記保護対象回路との間の経路上の長さよりも短い電圧保護装置。     In the voltage protection device according to claim 1,
    The DC power is supplied to the protection circuit from the DC power supply via the positive electrode terminal and the negative electrode terminal.
    The length on the path between the voltage breakdown element and the positive electrode terminal, and between the voltage breakdown element and the negative electrode terminal is a voltage shorter than the length on the path between the voltage breakdown element and the protected circuit. Protective device.
  3. 　請求項１に記載の電圧保護装置において、
    　前記電圧降伏素子と前記保護対象回路との間の経路上に、電流の変動を抑制するインダクタ素子を備えた電圧保護装置。     In the voltage protection device according to claim 1,
    A voltage protection device including an inductor element that suppresses current fluctuations on a path between the voltage breakdown element and the protection target circuit.
  4. 　請求項１から請求項３までのいずれか一項に記載の電圧保護装置において、
    　前記電流遮断素子は、所定値以上の電流が流れた場合に溶断することで電流を遮断する抵抗素子であり、
    　前記抵抗素子は、溶断された場合に溶断箇所が所定以上の絶縁距離を形成する電圧保護装置。     In the voltage protection device according to any one of claims 1 to 3.
    The current cutoff element is a resistance element that cuts off the current by fusing when a current of a predetermined value or more flows.
    The resistance element is a voltage protection device that forms an insulation distance of a predetermined value or more at a fractured portion when it is fused.
  5. 　請求項１から請求項３までのいずれか一項に記載の電圧保護装置において、
    　前記保護対象回路は、電源を供給する電源回路であり、
    　前記電源回路は、絶縁トランスと、前記絶縁トランスの一次巻線に直列に接続されるスイッチング素子と、を有し、
    　前記電圧降伏素子の降伏電圧は、前記スイッチング素子の耐電圧より小さい値である電圧保護装置。     In the voltage protection device according to any one of claims 1 to 3.
    The protected circuit is a power supply circuit that supplies power.
    The power supply circuit includes an isolation transformer and a switching element connected in series with the primary winding of the isolation transformer.
    A voltage protection device in which the breakdown voltage of the voltage breakdown element is smaller than the withstand voltage of the switching element.
  6. 　請求項５に記載の電圧保護装置において、
    　前記電源回路は、前記直流電源より供給される前記直流電力を交流電力に変換する電力変換装置の制御部へ電源を供給する電圧保護装置。     In the voltage protection device according to claim 5,
    The power supply circuit is a voltage protection device that supplies power to a control unit of a power conversion device that converts the DC power supplied from the DC power supply into AC power.
  7. 　直流電源からの直流電力が供給される保護対象回路と、
    　前記直流電源と前記保護対象回路との間に配置され、前記保護対象回路を過電圧から保護する保護回路と、を備える電圧保護装置であって、
    　前記保護回路は、所定以上の電流が流れた時に溶断して電流を遮断する電流遮断素子と、前記保護対象回路と電気的に並列に前記電流遮断素子と前記保護対象回路との間に接続され、所定以上の電圧が印加された時に導通する電圧降伏素子と、を備え、
    　前記電圧降伏素子の降伏電圧は、前記保護対象回路に入力される通常動作電圧より大きく、かつ、前記保護対象回路の所定の耐電圧より小さい値であり、
    　前記電圧降伏素子と前記保護対象回路との間の経路上に、電流の変動を抑制するインダクタ素子を備えた電圧保護装置。     A protected circuit to which DC power is supplied from a DC power supply, and
    A voltage protection device including a protection circuit arranged between the DC power supply and the protection target circuit and protecting the protection target circuit from overvoltage.
    The protection circuit is connected between a current cutoff element that blows and cuts off the current when a current of a predetermined value or more flows, and the current cutoff element and the protection target circuit in electrical parallel with the protection target circuit. A voltage breakdown element that conducts when a voltage higher than a predetermined value is applied.
    The breakdown voltage of the voltage breakdown element is a value larger than the normal operating voltage input to the protection target circuit and smaller than a predetermined withstand voltage of the protection target circuit.
    A voltage protection device including an inductor element that suppresses current fluctuations on a path between the voltage breakdown element and the protection target circuit.
  8. 　請求項７に記載の電圧保護装置において、
    　前記保護対象回路は、前記直流電源より供給される直流電力を交流電力に変換する電力変換装置の制御部へ電源を供給する電源回路であり、
    　前記電源回路は、絶縁トランスと、前記絶縁トランスの一次巻線に直列に接続されるスイッチング素子と、を有し、
    　前記電圧降伏素子の降伏電圧は、前記スイッチング素子の耐電圧より小さい値である電圧保護装置。     In the voltage protection device according to claim 7,
    The protected circuit is a power supply circuit that supplies power to the control unit of a power conversion device that converts DC power supplied from the DC power supply into AC power.
    The power supply circuit includes an isolation transformer and a switching element connected in series with the primary winding of the isolation transformer.
    A voltage protection device in which the breakdown voltage of the voltage breakdown element is smaller than the withstand voltage of the switching element.
  9. 　請求項１または請求項７に記載の電圧保護装置と、
    　スイッチング素子により構成されるインバータ回路と、
    　前記インバータ回路を駆動する駆動信号を生成する制御部とを備え、
    　前記保護対象回路は、前記制御部へ電源を供給する電源回路であり、
    　前記直流電源より供給される直流電力を前記インバータ回路により交流電力に変換する電力変換装置。     The voltage protection device according to claim 1 or 7.
    Inverter circuit composed of switching elements and
    A control unit that generates a drive signal for driving the inverter circuit is provided.
    The protection target circuit is a power supply circuit that supplies power to the control unit.
    A power conversion device that converts DC power supplied from the DC power supply into AC power by the inverter circuit.
PCT/JP2020/047356 2020-02-03 2020-12-18 Voltage protection device and power converter WO2021157222A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2020-016477 2020-02-03
JP2020016477A JP2023027424A (en) 2020-02-03 2020-02-03 Voltage protection device and power conversion device

Publications (1)

Publication Number Publication Date
WO2021157222A1 true WO2021157222A1 (en) 2021-08-12

Family

ID=77199982

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2020/047356 WO2021157222A1 (en) 2020-02-03 2020-12-18 Voltage protection device and power converter

Country Status (2)

Country Link
JP (1) JP2023027424A (en)
WO (1) WO2021157222A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024075305A1 (en) * 2022-10-07 2024-04-11 日立Astemo株式会社 Electric power conversion device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0680345U (en) * 1993-04-20 1994-11-08 松下電器産業株式会社 Circuit protector
JP2014007883A (en) * 2012-06-26 2014-01-16 Denso Corp Circuit protection device
JP2017187397A (en) * 2016-04-06 2017-10-12 トヨタ自動車株式会社 Temperature detection apparatus
JP2018191400A (en) * 2017-04-28 2018-11-29 キヤノン株式会社 Power supply apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0680345U (en) * 1993-04-20 1994-11-08 松下電器産業株式会社 Circuit protector
JP2014007883A (en) * 2012-06-26 2014-01-16 Denso Corp Circuit protection device
JP2017187397A (en) * 2016-04-06 2017-10-12 トヨタ自動車株式会社 Temperature detection apparatus
JP2018191400A (en) * 2017-04-28 2018-11-29 キヤノン株式会社 Power supply apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024075305A1 (en) * 2022-10-07 2024-04-11 日立Astemo株式会社 Electric power conversion device

Also Published As

Publication number Publication date
JP2023027424A (en) 2023-03-02

Similar Documents

Publication Publication Date Title
US8400739B2 (en) System and method for operating inverters
JP4626809B2 (en) Overvoltage protection circuit
KR101756578B1 (en) Power supply device
US20120018777A1 (en) Three level power converting device
JPH10210758A (en) Power converter circuit
JP2009506736A (en) Power conversion circuit with distributed energy storage
US20120248864A1 (en) System and Method for Operating Inverters
JP6646870B2 (en) Chopper device
US10574131B2 (en) Converter having short-circuit interruption in a half-bridge
US9912225B2 (en) Method and system for overcurrent protection for insulated-gate bipolar transistor (IGBT) modules
WO2021157222A1 (en) Voltage protection device and power converter
US20110031815A1 (en) Fuse for disconnecting an inverter from a photovoltaic generator
US20140118873A1 (en) Power module and apparatus for preventing malfunction, and method of controlling thereof
US20200169163A1 (en) Power electronic device
JP6952840B1 (en) Switching equipment and power conversion equipment
JP6844587B2 (en) Drive circuit
JP5003618B2 (en) Fuel cell power converter
US20120217918A1 (en) Inverter
JPH05219752A (en) Short circuit protecting device for power converter
JP4003255B2 (en) Protective device for electric device for vehicle
CN110620370B (en) Safety design for DC-side capacitor
JP5421049B2 (en) Surge voltage suppression device and motor control device
CN110797836B (en) Circuit for switching power supply in motor driver, operation method and motor driving circuit system
JP2007234688A (en) Semiconductor device with overvoltage protection circuit
WO2010122861A1 (en) Inverter protecting apparatus

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20917658

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20917658

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP