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WO2015018019A1 - Procédé et dispositif de mesure de l'impédance entre un fil sous tension et un fil de terre d'une alimentation électrique - Google Patents

Procédé et dispositif de mesure de l'impédance entre un fil sous tension et un fil de terre d'une alimentation électrique Download PDF

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Publication number
WO2015018019A1
WO2015018019A1 PCT/CN2013/081047 CN2013081047W WO2015018019A1 WO 2015018019 A1 WO2015018019 A1 WO 2015018019A1 CN 2013081047 W CN2013081047 W CN 2013081047W WO 2015018019 A1 WO2015018019 A1 WO 2015018019A1
Authority
WO
WIPO (PCT)
Prior art keywords
impedance
neutral
wire
terminal
voltage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2013/081047
Other languages
English (en)
Chinese (zh)
Inventor
龙基智
吴忠良
洪少林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Uni Trend Technology China Co Ltd
Original Assignee
Uni Trend Technology China Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Uni Trend Technology China Co Ltd filed Critical Uni Trend Technology China Co Ltd
Priority to PCT/CN2013/081047 priority Critical patent/WO2015018019A1/fr
Publication of WO2015018019A1 publication Critical patent/WO2015018019A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G01R27/025—Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G01R27/16—Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line

Definitions

  • the invention relates to the technical field of parameter measurement of electrical equipment, and in particular to a device and a method for measuring impedance between a power line and a ground. Background technique
  • FIG. 1 the figure is a schematic diagram of a power frequency civil power system in the prior art.
  • the transformer 200 converts the high voltage power supplied by the high voltage power supply system 100 into a power frequency civil power source.
  • the RCD leakage protector 300 is used between the commercial frequency power supply port 400 and the power frequency civil power supply.
  • the function of the RCD leakage protector 300 is overcurrent protection. When the current from the live line to the neutral line is greater than the protection value, it will protect. Second, the leakage protection will protect the leakage when the leakage is greater than 30mA, that is, the fire line is The zero line has a protective effect when the current is greater than 30 mA.
  • the RCD leakage protector 300 only protects against leakage current between the live line L and the neutral line N.
  • the invention provides a device and a method for measuring impedance between a power line and a ground line, which can accurately obtain an impedance between a live line and a ground line.
  • Embodiments of the present invention provide a method for measuring impedance between a power line and a ground line, including: obtaining an impedance of a live line to a neutral line to obtain an impedance of a neutral line to a ground line, and obtaining a zero line impedance R N;
  • the impedance of obtaining the live line to the neutral line is specifically:
  • the load resistor R is not connected to the live terminal and the neutral terminal of the commercial frequency power supply port. , detecting the second voltage of the hot line end and the zero line end ⁇ ;
  • the obtaining the zero line impedance ⁇ is specifically:
  • the embodiment of the invention further provides a measuring device for the impedance between the power line and the ground line, comprising: an impedance detecting circuit;
  • the impedance detecting circuit is configured to obtain the impedance of the live line to the neutral line ⁇ , and obtain the zero line to the ground line Impedance £ , obtain the zero line impedance; use the formula to get the impedance of the live line to ground:
  • the impedance detecting circuit comprises: a load resistor, a first voltage detecting module, a second voltage detecting module and a controller;
  • the first voltage detecting module is connected to the load resistor R at the hot end and the neutral end of the commercial port of the commercial power source. , for detecting the first voltage t/ A of the live end and the neutral end;
  • the impedance detecting circuit further includes: a voltage detecting module;
  • the voltage detecting module is configured to detect a voltage v 2 between a neutral line and a ground line node to a neutral line end;
  • the impedance detecting circuit further comprises: a constant current given module and a third voltage detecting module And a fourth voltage detecting module;
  • the constant current given module is configured to apply a given current / at the neutral end and the ground end;
  • the third voltage detecting module is configured to detect a third voltage v 3 of the zero line end and the ground line end before a given current / before the neutral line end and the ground line end are applied;
  • the fourth voltage detecting module is configured to detect a fourth voltage v 4 of the zero line end and the ground line end after applying a given current / after the neutral line end and the ground line end;
  • the value of the given current / is less than the trigger value of the action of the RCD leakage protector.
  • the impedance detecting circuit further includes: a low frequency generator; the low frequency generator is connected to the constant current given module;
  • the low frequency generator is configured to make the frequency of the given current / less than 1 ⁇ .
  • the impedance detecting circuit further comprises: an AD converter and a low pass filter;
  • the third voltage detecting module and the fourth voltage detecting module are both connected to the low pass filter; the low pass filter is configured to filter the third voltage and the fourth voltage and send the AD converter;
  • the AD converter is configured to convert the third voltage and the fourth voltage into digital signals and send them to the controller.
  • the present invention has the following advantages:
  • R £ can be obtained.
  • the three ports are indirectly measured by different means, and the impedance values of ⁇ , and are respectively obtained, and the value of the loop impedance R £ is obtained by calculation; the present invention obtains the relationship between the live line and the ground line by transforming the measurement method.
  • the loop impedance, this implementation is reliable, and ensures that all RCD protectors are not protected (cannot trip).
  • FIG. 1 is a grid-connected inverter circuit diagram of a single-phase full-bridge output in the prior art
  • FIG. 3 is a schematic diagram of an impedance detecting apparatus provided by the present invention.
  • FIG. 6 is a schematic view showing a fourth embodiment of a device for measuring impedance between a power line and a ground line provided by the present invention.
  • Embodiment 7 is a schematic diagram of Embodiment 5 of a device for measuring impedance between a power line and a ground line provided by the present invention
  • Fig. 8 is a schematic view showing a sixth embodiment of a measuring device for impedance between a power line and a ground line provided by the present invention.
  • FIG. 2 the figure is a flowchart of Embodiment 1 of a method for measuring impedance between a power line and a ground line provided by the present invention.
  • R £ can be obtained.
  • the three ports are indirectly measured by different means, and the impedance values of ⁇ , R and respectively are obtained, and the value of the loop impedance R £ is obtained by calculation; the present invention obtains the relationship between the live line and the ground line by transforming the measurement method.
  • the loop impedance, this implementation is reliable, and ensures that all RCD protectors are not protected (cannot trip).
  • FIG. 3 the figure is a schematic diagram of an impedance detecting apparatus provided by the present invention.
  • the load resistor R is connected to the live terminal and the neutral terminal of the commercial port of the commercial power supply. , detecting the first voltage t/ A of the live end and the neutral end;
  • the ports of FireWire L, Neutral N and Ground E can be detected in the commercial power port 400 of the commercial power supply.
  • R 0 may be mounted between the live L and neutral N ports, and the hot terminal voltage before and after the zero line end R 0 hook detection, can be obtained in accordance with Thevenin's theorem
  • the principle used is that the current in the loop is the same, ie R.
  • the current flowing up is the same as the current flowing up.
  • £ obtained in principle in the embodiment of the present invention is applied to a constant current between the neutral terminal and the ground terminal, and then measuring the voltage between the neutral terminal and a ground terminal, so that the voltage measurement and the known constant current, and The impedance of the neutral terminal and the ground terminal can be obtained.
  • the impedance obtained from the neutral line to the ground line is specifically:
  • the third line y 3 of the zero line end and the ground line end is detected when the zero line end and the ground line end are not applied with a given current/front;
  • the present invention first measures the third voltage V 3 at the neutral terminal and the ground terminal, and finally divides the difference between ⁇ 4 and ⁇ 3 by a given current to eliminate the interference signal. , the ⁇ obtained in this way is more accurate.
  • the given current / frequency is lower than 1 Hz, the purpose is to avoid the power frequency interference and clutter interference of the given current, and the other is to facilitate the subsequent measurement of the voltage signal ( ⁇ 4 and ⁇ 3 ) Processing.
  • the given current / size is not enough to trigger the RCD leakage protector action, ie The value of the given current / is less than the trigger value of the RCD leakage protector action.
  • a given current / size is 14.5 mA as an example.
  • R LE R 0 + V 2 / (U A / R 0 , - 2 ⁇ ⁇ , based on the method for measuring the impedance between the power line and the ground line provided by the above embodiment, the present invention is implemented
  • the example also provides a measuring device for the impedance between the power line and the ground line, which will be described in detail below with reference to the accompanying drawings.
  • R LE R LN + R NE ⁇ 2R N.
  • the three ports of the civil power frequency power supply the live line end, the neutral line end and the ground line end, the RCD protector is installed in the line, and the large current measurement cannot be directly performed on the three ports; therefore, the solution provided by the present invention
  • the three ports are indirectly measured by different means, and the impedance values of ⁇ , £ and respectively are obtained, and the value of the loop impedance R £ is obtained by calculation; the present invention obtains the relationship between the live line and the ground line by transforming the measurement method.
  • the loop impedance is such that the implementation is reliable and ensures that all RCD protectors are not protected (cannot trip).
  • FIG. 4 the figure is a schematic diagram of Embodiment 2 of a device for measuring impedance between a power line and a ground line provided by the present invention. How to obtain in this embodiment is described.
  • the impedance detecting circuit includes: a load resistor R. a first voltage detecting module 401, a second voltage detecting module 402, and a controller 403;
  • the first voltage detecting module 401 is connected to the load resistor R at the hot end and the neutral end of the commercial port of the commercial power source. , for detecting the first voltage of the hot end and the zero end ⁇ ;
  • the second voltage detecting module 402 does not connect the load resistor R to the live end and the neutral end of the commercial port of the commercial power source. , for detecting the second voltage of the live end and the neutral end ⁇ ;
  • the controller 403 is configured to obtain the impedance of the live line to the neutral line by the Thevenin theorem
  • the ports of FireWire L, Neutral N and Ground E can be detected in the commercial power port 400 of the commercial power supply.
  • FIG. 5 the figure is a schematic diagram of Embodiment 3 of a device for measuring impedance between a power line and a ground line provided by the present invention.
  • the impedance detecting circuit further includes: a voltage detecting module
  • FIG. 6 is a schematic diagram of Embodiment 4 of a device for measuring impedance between a power line and a ground line provided by the present invention.
  • the measuring device provided in this embodiment is characterized in that: the impedance detecting circuit further comprises: a constant current given module 405, a third voltage detecting module 406 and a fourth voltage detecting module 407;
  • the constant current given module 405 is configured to apply a given current / at the neutral terminal and the ground terminal;
  • the third voltage detecting module 406 is configured to detect a third voltage v 3 of the neutral terminal and the ground terminal before a given current I is applied to the neutral terminal and the ground terminal;
  • the fourth voltage detecting module 407 is configured to detect a fourth voltage v 4 at the neutral end and the ground end after applying a given current / at the neutral end and the ground end;
  • £ obtained in principle in the embodiment of the present invention is applied to a constant current between the neutral terminal and the ground terminal, and then measuring the voltage between the neutral terminal and a ground terminal, so that the voltage measurement and the known constant current, and The impedance of the neutral terminal and the ground terminal can be obtained.
  • the present invention first measures the third voltage V 3 at the neutral terminal and the ground terminal, and finally divides the difference between ⁇ 4 and ⁇ 3 by a given current to eliminate the interference signal. , the ⁇ obtained in this way is more accurate.
  • the magnitude of the given current / is not sufficient to trigger the RCD leakage protector action, i.e., the value of the given current / is less than the trigger value of the RCD leakage protector action.
  • a given current / size is 14.5 mA as an example.
  • FIG. 7 is a schematic diagram of Embodiment 5 of a device for measuring impedance between a power line and a ground line provided by the present invention.
  • the impedance detecting circuit further includes: a low frequency generator 408; the low frequency generator 408 is connected to the constant current given module;
  • the low frequency generator 408 is configured to cause the frequency of the given current / to be less than 1 ⁇ .
  • the frequency of the given current / is lower than 1 Hz, the purpose is to avoid the power frequency interference and clutter interference of the given current, and the other is to facilitate the subsequent measurement of the voltage signal (V 4 and Processing of V 3 ).
  • the impedance detecting circuit further includes: an AD converter 409 and a low pass filter 410;
  • the third voltage detecting module 406 and the fourth voltage detecting module 407 are both connected to the low pass filter 410;
  • the low pass filter 410 is configured to filter the third voltage and the fourth voltage and send the signal to the AD converter 409;
  • the function of the low pass filter 410 is to filter the power line interference from the neutral line end to the ground line and other clutter signals.
  • the AD converter 409 is configured to convert the third voltage and the fourth voltage into digital signals for transmission to the controller 403.
  • the measuring device provided by the above embodiment of the present invention can indirectly obtain the impedance from the live end to the ground end by measuring each impedance value and voltage value.
  • Example 6 is a schematic diagram.
  • the first step closing the switch 44, the contact 4 is reliably turned on the constant current given module 405; and the contact 6 is connected to the COM end;
  • the COM terminal is a common point of the measuring device, so that the ground wire has an electrical connection relationship with the device.
  • Step 2 Before detecting the current, first detect the interference and DC components from the neutral terminal to the ground terminal (ie 5 to 6); filter the 5 to 6 interference signal through the low-pass filter 410 and retain a DC component (third voltage V3); the DC component is converted into a digital signal by the AD converter 409, and sent to the controller 403; the controller 403 calculates a DC component (V3) of the zero line to the ground before the current is applied;
  • the third step the constant current given module 405 outputs a constant current, which can be preferably output in this embodiment.
  • Step 4 Turn on the low frequency generator 408, so that the frequency of the current output by the constant current given module 405 is lower than 1 Hz, that is, the current below 1 Hz flows from the 5 end of the zero line to the 6 segments of the ground line; The ends are connected. Therefore, the fourth voltage V4 generated by loading the current from the neutral line to the ground line through the low pass filter 410 is restored.
  • R LE B £A_ , 3 ⁇ 4 + ⁇ 2 / ([ / ⁇ / 3 ⁇ 4 ) - 2 ( ⁇ 3 ⁇ 4 calculates the impedance of the live line to the ground.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Resistance Or Impedance (AREA)

Abstract

La présente invention concerne un procédé et un dispositif de mesure de l'impédance entre un fil sous tension et un fil de terre d'une alimentation électrique, le procédé comprenant : l'acquisition de l'impédance RLN entre le fil sous tension et le fil neutre, de l'impédance RNE entre le fil neutre et le fil de terre, et de l'impédance RN du fil neutre; et l'utilisation d'une formule pour acquérir l'impédance entre le fil sous tension et le fil de terre, c'est-à-dire RLE=RLN+RNE-2RN, de sorte que RLE est obtenue par la mesure de RLN, de RNE et de RN. Comme les alimentations électriques à fréquence industrielle civile comportent trois accès (un accès de fil sous tension, un accès de fil neutre et un accès de fil de terre) et qu'un protecteur RCD est installé dans les circuits des accès, la mesure d'un courant de haute intensité ne peut donc pas être réalisée directement sur les trois accès; pour effectuer cette mesure, un moyen différent est utilisé pour mesurer de manière indirecte les trois accès afin d'obtenir les valeurs d'impédance RLN, RNE et RN, et la valeur de l'impédance de boucle RLE est obtenue par calcul. La présente invention permet d'obtenir une impédance de boucle entre un fil sous tension et un fil de terre simplement en changeant de procédé de mesure, le procédé étant ainsi simple et fiable, et la présente invention permet en outre d'empêcher tous les protecteurs RCD de fonctionner (déclenchement).
PCT/CN2013/081047 2013-08-08 2013-08-08 Procédé et dispositif de mesure de l'impédance entre un fil sous tension et un fil de terre d'une alimentation électrique Ceased WO2015018019A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2013/081047 WO2015018019A1 (fr) 2013-08-08 2013-08-08 Procédé et dispositif de mesure de l'impédance entre un fil sous tension et un fil de terre d'une alimentation électrique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2013/081047 WO2015018019A1 (fr) 2013-08-08 2013-08-08 Procédé et dispositif de mesure de l'impédance entre un fil sous tension et un fil de terre d'une alimentation électrique

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3835798A1 (fr) * 2019-12-12 2021-06-16 HT Italia S.r.l. Procédé et appareil de mesure de l'impédance de la boucle de défaut

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6288553B1 (en) * 1997-10-18 2001-09-11 Ch. Beha Gmbh Technische Neuentwicklungen Method for determining the loop resistance of a power supply network
GB2380554A (en) * 2001-10-02 2003-04-09 Robin Electronics Ltd Circuit Tester
GB2408809A (en) * 2003-12-03 2005-06-08 Kyoritsu Elect Inst Work Power line loop impedance testing
EP1950575A2 (fr) * 2007-01-23 2008-07-30 Seaward Electronic Limited Procédé et appareil pour déterminer l'impédance d'une boucle courant-neutre d'une alimentation électrique
CN103399208A (zh) * 2013-08-08 2013-11-20 优利德科技(中国)有限公司 一种电源火线与地线之间阻抗的测量装置及方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6288553B1 (en) * 1997-10-18 2001-09-11 Ch. Beha Gmbh Technische Neuentwicklungen Method for determining the loop resistance of a power supply network
GB2380554A (en) * 2001-10-02 2003-04-09 Robin Electronics Ltd Circuit Tester
GB2408809A (en) * 2003-12-03 2005-06-08 Kyoritsu Elect Inst Work Power line loop impedance testing
EP1950575A2 (fr) * 2007-01-23 2008-07-30 Seaward Electronic Limited Procédé et appareil pour déterminer l'impédance d'une boucle courant-neutre d'une alimentation électrique
CN103399208A (zh) * 2013-08-08 2013-11-20 优利德科技(中国)有限公司 一种电源火线与地线之间阻抗的测量装置及方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3835798A1 (fr) * 2019-12-12 2021-06-16 HT Italia S.r.l. Procédé et appareil de mesure de l'impédance de la boucle de défaut

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