WO2015018019A1 - Method and device for measuring impedance between live wire and earth wire of power supply - Google Patents

Method and device for measuring impedance between live wire and earth wire of power supply Download PDF

Info

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
Grant status
Application
Patent type
Prior art keywords
impedance
voltage
line
terminal
ground
Prior art date
Application number
PCT/CN2013/081047
Other languages
French (fr)
Chinese (zh)
Inventor
龙基智
吴忠良
洪少林
Original Assignee
优利德科技(中国)有限公司
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

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G01R27/025Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G01R27/16Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line

Abstract

Provided are a method and device for measuring impedance between the live wire and earth wire of a power supply, the method comprising: acquiring live wire-to-neutral wire impedance RLN, neutral wire-to-earth wire impedance RNE, and neutral wire impedance RN; and using a formula to acquire live wire-to-earth wire impedance, that is, RLE=RLN+RNE-2RN, such that RLE is obtained by measuring RLN, RNE and RN. Because a civil power frequency power supply has three ports: a live wire port, a neutral wire port and an earth wire port, and an RCD protector is installed in the circuits of the ports, so heavy current measurement cannot be directly conducted on the three ports; instead, using a different means to indirectly measure the three ports so as to obtain the impedance values RLN, RNE and RN, and obtaining a loop impedance RLE value through calculation. The present invention obtains loop impedance between a live wire and an earth wire by simply changing the measurement method, thus being simple and reliable, and prevents all RCD protectors from functioning (tripping).

Description

A power supply apparatus and method for measuring the impedance between the hot and ground

FIELD

Parameter measurement Technical Field The present invention relates to an electrical apparatus, and particularly to apparatus and method for measuring impedance between the live wire of a power and ground. Background technique

Referring to Figure 1, the prior art picture shows a system diagram of the commercial electric source frequency.

The high voltage transformer 200 provides high-voltage power supply system 100 is converted into commercial electric source frequency.

In order to ensure the safety of civilian power in the commercial power supply port 400 civilian and frequency leakage protection using RCD 300 between the civilian power.

RCD 300 acting leakage protection First, overcurrent, line-to-zero when the current line is greater than the protective effect protection value; second leakage protection, when the leakage is generally greater than 30mA will play a protective role, that is to FireWire protective effect on residual current greater than 30mA zero line.

However, RCD leakage protection device 300 is merely a leakage current protection between live line L and neutral line N of the embodiment.

Thus, the prior art does not only prevent leakage protection RCD trips, the method can accurately measure the impedance between the live and ground E, L.

SUMMARY

The present invention provides an apparatus and method for measuring the impedance of the power supply, it is possible to accurately obtain the impedance between the live line and the ground between the hot and ground.

Embodiment of the present invention provides a method of measuring the impedance between the live wire of a power and ground, comprising: obtaining the zero line-to-line impedance to obtain a zero impedance in the ground line ^, to obtain a zero line impedance R N;

Use a formula to get the line of fire impedance in the ground:

Figure imgf000004_0001
Preferably, the impedance of the line-to-zero line is obtained specifically as follows:

In civil frequency power port hot terminal and neutral terminal connected to a load resistor R. Detecting a first voltage ^ hot terminal and neutral terminal;

In civil frequency power port hot terminal and neutral terminal is not connected to a load resistor R. Detecting hot terminal and neutral terminal of the second voltage ^;

FireWire obtained by the Thevenin's theorem to the zero line impedance R = * R 0.

UA

Preferably, the line impedance to obtain a zero ^, specifically:

In civil frequency power port hot terminal and neutral terminal connected to a load resistor R. Detecting a first voltage ^ hot terminal and neutral terminal;

Detecting a zero line and the ground line side of the node to zero voltage v 2;

Kirchhoff's current law can be obtained: R N = v 2 i A lR. . Preferably, the line to obtain a zero impedance £ ground, specifically:

Front neutral terminal and a ground terminal is not applied to the constant current /, the third voltage terminal and a ground terminal of the zero line to detect the zero line and the ground terminal end after a given applied current I, to detect the zero line end and a fourth ground terminal voltage v 4; the neutral wire impedance to ground £: £ =. Embodiments of the invention further provides a measuring device A power supply impedance between the live wire and ground, comprising: an impedance detecting circuit;

The impedance detection circuit for obtaining the zero line-to-line impedance ^, to obtain a zero impedance £ ground line, to obtain a zero line impedance; line-to-use formula obtained impedance in the ground:

R LE = R LN + R NE ~ 2R N. Preferably, said impedance detection circuit comprising: a load resistor, a first voltage detection module, the second voltage detecting module and a controller;

The first voltage detector module, in civil frequency power port hot terminal and neutral terminal connected to a load resistor R. , For detecting a first voltage t hot terminal and neutral terminal / A;

The second voltage detecting module, in civil frequency power port hot terminal and neutral terminal is not connected to a load resistor R. , For detecting a second voltage hot terminal and neutral terminal ^; a controller for obtaining the zero line-to-line impedance R = * R 0 by the Thevenin's theorem.

UA

Preferably, said impedance detection circuit further comprising: a voltage detection module;

The voltage detecting means for detecting the zero line and the ground line side of the node to zero voltage v 2;

The controller, for utilizing Kirchhoff's current law can be obtained: R N = V 2 I ( UR 0) 0 Preferably, said impedance detection circuit further comprising: a constant current of a given module, a third voltage detecting module and a fourth voltage detection module;

The currents in given module for the zero line and the ground terminal end of a given applied current /;

The third voltage detection module for neutral ground terminal end and does not apply a current / previous given, detecting a zero line and the ground terminal end of the third voltage v 3;

The fourth voltage detection module for neutral ground terminal end and applying a given current /, the neutral detection terminal and a ground terminal of the fourth voltage v 4;

The controller for the said given current /, the third voltage and the fourth voltage. 3 ¥ ¥. 4 to calculate the zero impedance in the ground line £ = ϋ. Preferably, said given current / constant value less than the trigger value RCD leakage protection operation.

Preferably, said impedance detection circuit further comprising: a low-frequency generator; said low frequency constant current generator and the given module is connected;

Said low frequency generator, the frequency for a given current / is less than 1Ηζ.

Preferably, said impedance detection circuit further comprising: AD converters and low pass filter;

The third voltage and the fourth voltage detection module detection modules are connected to the low pass filter; the low pass filter, for the later issued to the third voltage and the fourth voltage filter AD converter;

The AD converter, for transmission to the controller after the third voltage and the fourth voltage is converted to a digital signal.

Compared with the prior art, the present invention has the following advantages:

Thus by measuring respectively ^^, R NE and R N, it can be obtained R £. Since the three ports civil power frequency: hot terminal, neutral terminal and a ground terminal, with its line RCD protection, these three ports can not directly measure the large current; Accordingly, the present invention provides a solution indirect these three ports by means of different measurements, respectively ^^, and the resistance value, and the value of the loop impedance obtained by calculating £ R & lt; present invention is obtained by measurement transition between the hot and the ground loop impedance, such implementations reliable single cylinder; and to ensure that all of the RCD protection can not protect (not trip). BRIEF DESCRIPTION

FIG phase full bridge output of the prior art circuit diagram of a single grid-connected inverter;

Figure;

FIG 3 is a schematic diagram of the present invention provides an impedance detection apparatus; Figure; FIG;

FIG 6 is an impedance measuring device between the live wire and ground invention provides a schematic view of a four embodiment;

FIG. 7 is an embodiment of the measuring device and the impedance between the live wire of the present invention provides a ground five schematic;

FIG 8 is a schematic diagram of six impedance measuring means between the power supply and ground FireWire embodiment of the present invention provides.

detailed description

For the above objects, features and advantages of the present invention can be more fully understood by reading the following description of the drawings in detail specific embodiments of the present invention binds.

Referring to Figure 2, a flowchart diagram of a method of measuring the impedance of the graph between the power supply and ground FireWire embodiment of the present invention provides.

The method of measuring the impedance between the live wire and the ground is provided in this embodiment, comprising:

S201: obtaining the zero line-to-line impedance ^, to obtain a zero impedance in the ground line £, to obtain a zero line impedance;

S202: using the formula (1) to obtain the line-to-ground impedance: R LE = R W + R NE _2R N (1) can be seen from Figure 1, the ground impedance FireWire L E, R £ = R + R £ (2)

^ ■ fR LE = R L + R E = R w + R NE -2R N (3)

Thus, it can be obtained in accordance with R & lt £ £ = ^^ + £ -2. Thus by measuring respectively ^^, R NE and R N, it can be obtained R £. Since the three ports civil power frequency: hot terminal, neutral terminal and a ground terminal, with its line RCD protection, these three ports can not directly measure the large current; Accordingly, the present invention provides a solution indirect measurement of these three ports by different means, respectively ^^, R and resistance value, and the value obtained by calculation loop impedance £ R & lt; the invention by transforming the measurement to be obtained between the hot and ground the loop impedance, such implementations reliable single cylinder; and to ensure that all of the RCD protection can not protect (not trip).

The following procedure to obtain more detailed description in conjunction with the accompanying drawings 3 three specific impedance.

Referring to Figure 3, a schematic diagram of an impedance detection device of the present invention provides the graph.

Firstly, the process of obtaining.

Embodiments of the present invention is obtained based on the Thevenin's theorem.

First, in civil frequency power port hot terminal and neutral terminal connected to a load resistor R. Detecting hot terminal and neutral terminal of the first voltage t / A;

In civil frequency power port hot terminal and neutral terminal is not connected to a load resistor R. , The second voltage detecting hot terminal and neutral terminal ^; Thevenin's theorem is obtained from the firing line to the zero line impedance R w = * R 0.

UA

3, Firewire port L, neutral N and the ground line E in civil frequency power port 400 can be detected.

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

Let's continue in conjunction with Figure 3 how to get introduced. In civil frequency power port hot terminal and neutral terminal connected to a load resistor R. Detecting a first voltage ^ hot terminal and neutral terminal;

Detecting a zero line and the ground line side of the node to zero voltage v 2;

Kirchhoff's current law can be obtained: (. T / A / R ) = V 2 /.

When available, take advantage of the current loop principle is the same, namely R. And the current flowing through the current flowing through the same.

The following details how to get £.

£ 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 neutral impedance can be obtained and the ground terminal end.

The line to obtain a zero impedance in the ground, in particular:

Neutral terminal and a ground terminal is not applied to a current / previous given detection neutral ground terminal and the third terminal of the voltage y 3;

After the end of the earth line and the ground line applying a given current I, the zero detection line terminal and a ground terminal of the fourth voltage v 4; the neutral wire impedance to ground £: £ = ^} i.

Incidentally, the present invention prior to application of a given current, the first measurement of the neutral and the ground terminal end of the third voltage V 3, and finally with a differential ¥ ¥. 4. 3 divided by a given current, in order to eliminate the interference signal ^ obtained in this way is more accurate.

Note that, given current / frequency of less than 1Hz, - object area is subjected to a given current in order to avoid frequency interference and noise interference, on the other hand in order to facilitate subsequent voltage measurement signal (¥. 4 and ¥ 3) processing.

It will be appreciated that, given current / RCD is not large enough to trigger the operation of leakage protection, i.e. the value of the given current / RCD is less than the trigger value of the leakage protection operation.

Preferably, embodiments of the present invention, the size of a given current / 14.5mA for example.

In summary, R LE = R 0 + V 2 / (U A / R 0, - 2 ^ ^ ,. based on a measurement method of a power impedance between the live wire and ground provided in the above embodiment, embodiments of the present invention embodiments also provide impedance between the measurement device and ground to a power line of fire, the following detailed description in conjunction with the accompanying drawings sensing circuit.;

The impedance detection circuit for obtaining the zero line-to-line impedance ^, to obtain a zero impedance £ ground line, to obtain a zero line impedance; line-to-use formula obtained impedance in the ground:

R LE = R LN + R NE ~ 2R N.

R, £ and will be able to obtain R £. Since the three ports civil power frequency: hot terminal, neutral terminal and a ground terminal, with its line RCD protection, these three ports can not directly measure the large current; Accordingly, the present invention provides a solution indirect measurement of these three ports by different means, respectively ^^, £ and resistance value, and the value obtained by calculation loop impedance £ R & lt; the invention by transforming the measurement to be obtained between the hot and ground the loop impedance, such implementations reliable single cylinder; and to ensure that all of the RCD protection can not protect (not trip).

Describe below in conjunction with the accompanying drawings ^^ obtained, R NE and R N.

Referring to Figure 4, a schematic view of the graph according to the second measuring means and the impedance between the live wire of the present invention provides a ground embodiment. The present embodiment describes how to obtain.

The impedance detection circuit in the present embodiment is provided comprising: a load resistor R. , A first voltage detection module 401, a second voltage detection module 402 and a controller 403;

The first voltage detection module 401, in civil frequency power port hot terminal and neutral terminal connected to a load resistor R. , For detecting a first voltage hot terminal and neutral terminal ^;

The second voltage detecting module 402, in civil frequency power port hot terminal and neutral terminal is not connected to a load resistor R. , For detecting a second voltage hot terminal and neutral terminal ^;

The controller 403, for obtaining a FireWire Thevenin's theorem to the zero line impedance

3, Firewire port L, neutral N and the ground line E in civil frequency power port 400 can be detected.

It may be between the live L and neutral N port mount, articulated detected R. Before and after hot terminal and neutral terminal voltage, can be obtained in accordance with Thevenin's theorem ^ o

Referring to Figure 5, a schematic diagram of measurement apparatus three impedance between the live wire and ground the graph provided in the embodiment of the present invention.

Measuring means provided in this embodiment of the impedance detection circuit further comprising: a voltage detection module

404;

The voltage detection module 404 for detecting the zero to the zero line and the ground line side of the node voltage V 2; the controller 403, for utilizing Kirchhoff's current law can be obtained: = V 2 / (t / A / R.). When available, take advantage of the current loop principle is the same, namely R. And the current flowing through the current flowing through the same. Referring to Figure 6, embodiment of the measuring apparatus of the impedance between the live wire and the ground line graph of the present invention provides a schematic of four.

Measuring means provided in the present embodiment, wherein the impedance detection circuit further comprising: a constant current for a given module 405, a third voltage detection module 406 and a fourth voltage detection module 407;

The currents in given module 405, configured to neutral ground terminal end and applying a given current /;

The third voltage detecting module 406, configured to neutral terminal and a ground terminal is not applied before the given current I, to detect the zero line and the ground terminal end of the third voltage v 3;

The fourth voltage detecting module 407, configured to neutral ground terminal end and applying a given current /, the neutral detection terminal and a ground terminal of the fourth voltage v 4;

The controller 403, is used to calculate the zero line given by the current /, and the third voltage. 3 ¥ fourth voltage V 4 to the ground line impedance R NE = ϋ.

£ 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 neutral impedance can be obtained and the ground terminal end.

Incidentally, the present invention prior to application of a given current, the first measurement of the neutral and the ground terminal end of the third voltage V 3, and finally with a differential ¥ ¥. 4. 3 divided by a given current, in order to eliminate the interference signal ^ obtained in this way is more accurate.

It will be appreciated that, given current / RCD is not large enough to trigger the operation of leakage protection, i.e. the value of the given current / RCD is less than the trigger value of the leakage protection operation.

Preferably, embodiments of the present invention, the size of a given current / 14.5mA for example.

In summary, R LE = ^^ * R. + V 2 / φ A / R 0 _ 2 (^^. Referring to Figure 7, an embodiment of the impedance measuring means between the live wire and the ground line graph of the present invention provides a schematic view of five.

Measuring means provided in the present embodiment, the impedance detection circuit further comprising: a low frequency generator 408; 408 given the low frequency generator module connected to the constant current;

The low-frequency generator 408, the frequency for a given current / is less than 1Ηζ.

Note that, given current / frequency of less than 1Hz, - object area is subjected to a given current in order to avoid frequency interference and noise interference, on the other hand in order to facilitate subsequent voltage measurement signal (V 4 and V 3) is performed.

Measuring means provided in the present embodiment, the impedance detection circuit further includes: AD converters 409 and low pass filter 410;

The third voltage detection module 406 and 407 are a fourth voltage detecting module 410 is connected to the low pass filter;

The low-pass filter 410, a voltage after the third and fourth voltage filter 409 issued to the AD converter;

Low-pass filter 410 is a ground terminal of the zero line end frequency interference filter out noise and other signals.

The AD converter 409, for converting the third voltage and the fourth voltage is transmitted after a digital signal to the controller 403.

Measuring means provided in the above embodiment of the present invention, by measuring the respective voltage value and the resistance value can be obtained indirectly Firewire end of the impedance of the ground terminal.

The following describes in detail the process of the present invention provides a measuring device for impedance measurement is performed in conjunction with the accompanying drawings. Referring to Figure 8, a schematic diagram of six between the impedance measuring device graph live wire and ground provided by the embodiment of the present invention.

Step: closes the switch 44, the contacts 4 reliable ON currents in given module 405; and the contacts 6 connected to the end of COM;

Incidentally, the COM terminal is the common point of the measuring device, it is to make the ground and the electrical connection means have to have a relationship.

Step two: not added prior to the current neutral detecting first end to the ground terminal (i.e., 5-6) and the DC component of the interference; low-pass filter to filter out the interference signal 410 5-6 and retain DC component (the third voltage V3); the DC component by the AD converter 409 into a digital signal, sent to the controller 403; a controller 403 prior to calculating the current non-applied to neutral ground DC component (V3);

Third step: for a given constant current constant current output module 405, embodiments of the present embodiment may be the preferred output

14.5mA current;

Step Four: Open the low frequency generator 408, so that a constant current of a given frequency of the current module output 405 is less than 1Hz, 1Hz current segment is about less than 6 flows from the ground terminal 5 of the zero line; due to the COM terminal 6 end connection. Thus, low pass filter 410 in the load current zero line to the fourth voltage V4 generated by the ground to restore them. Meanwhile, the low-pass filter 410 to filter out frequency interference and other spurious and V4 AD converter 409 into a digital signal, sent to the controller 403; a controller 403 according to the formula R LE = B £ A_, ¾ + ν 2 / ([/ Α / ¾) - 2 (^ ¾ calculate the line-to-ground impedance of the above are only preferred embodiments of the present invention only, not form any limitation of the present invention though. methods and techniques embodied in the present invention has been disclosed above by the preferred embodiments, but not intended to limit the present invention. any person skilled in the art, without departing from the scope of the technical solution of the present invention, can take advantage of the present invention disclosed in the above-described technical solution made many possible variations and modifications, equivalent variations or modifications of equivalent embodiments. Accordingly, all without departing from the technical solutions of the present invention, any single-cylinder technical spirit of the present invention made of the above embodiment according to Example modifications, equivalents, modifications and variations, provided they fall within the scope of protection of the present invention.

Claims

Rights request
1, the impedance measurement between a line of fire of a power and ground, characterized by comprising: obtaining the zero line-to-line impedance to obtain a zero impedance in the ground line £, obtain a zero line impedance
R N;
Obtained using the equation of the line-to-ground impedance: R LE = R W + R NE _1R N.
2. The method of measuring the impedance between the power supply and ground line of fire as claimed in claim wherein, the obtaining of the line-to-line impedance ^ zero, specifically:
In civil frequency power port hot terminal and neutral terminal connected to a load resistor R. Detecting a first voltage ^ hot terminal and neutral terminal;
In civil frequency power port hot terminal and neutral terminal is not connected to a load resistor R. Detecting hot terminal and neutral terminal of the second voltage ^;
FireWire obtained by the Thevenin's theorem to the zero line impedance R = * R 0.
UA
3, the impedance measurement between the ground and the power supply according to claim FireWire, wherein the obtaining the zero line impedance ^, specifically:
In civil frequency power port hot terminal and neutral terminal connected to a load resistor R. Detecting a first voltage ^ hot terminal and neutral terminal;
Detecting a zero line and the ground line side of the node to zero voltage v 2;
Kirchhoff's current law can be obtained: R N = v 2 i A lR. .
4. The method of measuring the impedance between the power supply and ground line of fire as claimed in claim wherein said line to ground to obtain a zero impedance £, specifically:
Front neutral terminal and a ground terminal is not applied to the constant current /, the third voltage terminal and a ground terminal of the zero line to detect the zero line and the ground terminal end after a given applied current I, to detect the zero line end and a fourth ground terminal voltage v 4; the neutral wire impedance to ground £: £ =.
5, the impedance between the measuring device A power supply live wire and ground, characterized by comprising: an impedance detecting circuit;
The impedance detection circuit for obtaining the zero line-to-line impedance ^, to obtain a zero impedance £ ground line, to obtain a zero line impedance; line-to-use formula obtained impedance in the ground:
R LE = R LN + R NE ~ 2R N.
6, the measurement apparatus according to claim 5, wherein the impedance between the live wire and earth, characterized in that the impedance detection circuit comprising: a load resistor R. , A first voltage detection module, the second voltage detecting module and a controller;
The first voltage detector module, in civil frequency power port hot terminal and neutral terminal connected to a load resistor R. For detecting a hot terminal and neutral terminal of the first voltage t / A; the second voltage detection module, in civil frequency power port hot terminal and neutral terminal is not connected to a load resistor R. , For detecting a second voltage hot terminal and neutral terminal ^; a controller for obtaining the zero line-to-line impedance R = * R 0 by the Thevenin's theorem.
UA
7, the measuring device according to claim 6, the impedance between the live wire and earth, characterized in that the impedance detection circuit further comprising: a voltage detection module;
The voltage detecting means for detecting a zero to the zero line and the ground line side of the node voltage V 2; said controller, for using Kirchhoff's current law can be obtained: R N = V 2 / ( U A / R 0),
8. A measuring apparatus according to claim 5, wherein the impedance between the live wire and earth, characterized in that the impedance detection circuit further comprising: a constant current of a given module, the third voltage and the fourth voltage detecting module detecting module ;
The currents in given module for the zero line and the ground terminal end of a given applied current /;
The third voltage detection module for neutral ground terminal end and does not apply a current / previous given, detecting a zero line and the ground terminal end of the third voltage V 3;
The fourth voltage detection module for neutral ground terminal end and applying a given current /, the neutral detection terminal and a ground terminal of the fourth voltage v 4;
The controller for the said given current /, the third voltage and the fourth voltage. 3 ¥ ¥. 4 to calculate the zero impedance in the ground line £ = ϋ.
9. A measuring apparatus according to claim 8, the impedance between the live wire and earth, characterized in that the value of the given current / RCD is less than the trigger value of the leakage protection operation.
10, the measuring device according to claim 8, the impedance between the live wire and earth, characterized in that the impedance detection circuit further comprising: a low-frequency generator;
The low-frequency constant current generator and the given module is connected;
Said low frequency generator, the frequency for a given current / is less than 1Ηζ.
11, the measuring device according to claim 8, the impedance between the live wire and earth, characterized in that the impedance detection circuit further comprising: AD converters and low pass filter;
The third voltage and the fourth voltage detection module detection modules are connected to the low pass filter; the low pass filter, for the later issued to the third voltage and the fourth voltage filter AD converter;
The AD converter, for transmission to the controller after the third voltage and the fourth voltage is converted to a digital signal.
PCT/CN2013/081047 2013-08-08 2013-08-08 Method and device for measuring impedance between live wire and earth wire of power supply WO2015018019A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2013/081047 WO2015018019A1 (en) 2013-08-08 2013-08-08 Method and device for measuring impedance between live wire and earth wire of power supply

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2013/081047 WO2015018019A1 (en) 2013-08-08 2013-08-08 Method and device for measuring impedance between live wire and earth wire of power supply

Publications (1)

Publication Number Publication Date
WO2015018019A1 true true WO2015018019A1 (en) 2015-02-12

Family

ID=52460522

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2013/081047 WO2015018019A1 (en) 2013-08-08 2013-08-08 Method and device for measuring impedance between live wire and earth wire of power supply

Country Status (1)

Country Link
WO (1) WO2015018019A1 (en)

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 (en) * 2007-01-23 2008-07-30 Seaward Electronic Limited Method and apparatus for determining impedance of live-earth loop of electrical power supply
CN103399208A (en) * 2013-08-08 2013-11-20 优利德科技(中国)有限公司 Measuring device and method for impedance between live wire and ground wire of power supply

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 (en) * 2007-01-23 2008-07-30 Seaward Electronic Limited Method and apparatus for determining impedance of live-earth loop of electrical power supply
CN103399208A (en) * 2013-08-08 2013-11-20 优利德科技(中国)有限公司 Measuring device and method for impedance between live wire and ground wire of power supply

Similar Documents

Publication Publication Date Title
US7196884B2 (en) Apparatus and method for detecting the loss of a current transformer connection coupling a current differential relay to an element of a power system
CN201242570Y (en) Non-contact type high voltage phase-checking device
US20080150544A1 (en) Multi-ended fault location system
CN101526562A (en) Distributed wireless high-voltage equipment insulating live testing system and testing method
Ukil et al. Current-only directional overcurrent protection for distribution automation: challenges and solutions
CN102866326A (en) Distribution network fault line selection method based on zero sequence current variable quantity waveform correlation coefficient matrix
Majidi et al. Fault location in distribution networks by compressive sensing
JP2007225625A (en) Leakage current interrupting device and method
US20140117912A1 (en) System For Detecting Internal Winding Faults Of A Synchronous Generator, Computer Program Product And Method
JP2005140532A (en) Device and method for calculating phase angle, device and method for detecting leakage current
WO2016074742A1 (en) Differential protection method and differential protection device for performing a differential protection method
US20130088240A1 (en) Method and apparatus for determining an insulation resistance in grounded it systems
CN1645705A (en) Grounded fault selecting and protecting method for grouded system with small current
KR20080093169A (en) Method of leakage current break and measurement leakage current use phase calculation
JP2011015583A (en) Leakage detection method, leakage detection device, and earth leakage breaker
US6956726B2 (en) Power protection device
Li et al. Traveling wave-based protection scheme for inverter-dominated microgrid using mathematical morphology
CN1866043A (en) System and method for determining location of phase-to-earth fault
CN103094889A (en) Circuit single-phase earth fault impedance distance protection method based on additional impedance actual measurement correction
KR101118375B1 (en) Apparatus for swift determination of fault in electric power system
CN103439625A (en) Cable system fault positioning and load monitoring method
KR101317561B1 (en) Method for detecting ground fault of power line using wavelet transform
CN102680856A (en) Method for measuring zero sequence current of power transmission line based on magnetic sensor array
CN103576052A (en) System and method for determining direct-current system fault branch circuits needing to be in in-series connection with alternating currents
Dong et al. Implementation and application of practical traveling-wave-based directional protection in UHV transmission lines

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: 13891167

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase in:

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13891167

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 27.07.2016)

122 Ep: pct application non-entry in european phase

Ref document number: 13891167

Country of ref document: EP

Kind code of ref document: A1