KR100771583B1 - Measuring instrument for an electric current leakage - Google Patents

Measuring instrument for an electric current leakage Download PDF

Info

Publication number
KR100771583B1
KR100771583B1 KR1020060073430A KR20060073430A KR100771583B1 KR 100771583 B1 KR100771583 B1 KR 100771583B1 KR 1020060073430 A KR1020060073430 A KR 1020060073430A KR 20060073430 A KR20060073430 A KR 20060073430A KR 100771583 B1 KR100771583 B1 KR 100771583B1
Authority
KR
South Korea
Prior art keywords
circuit
current
voltage
output signal
detection circuit
Prior art date
Application number
KR1020060073430A
Other languages
Korean (ko)
Inventor
한송엽
고창섭
이용구
Original Assignee
이용구
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 이용구 filed Critical 이용구
Priority to KR1020060073430A priority Critical patent/KR100771583B1/en
Application granted granted Critical
Publication of KR100771583B1 publication Critical patent/KR100771583B1/en

Links

Images

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
    • G01R27/16—Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
    • G01R27/18—Measuring resistance to earth, i.e. line to ground

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)

Abstract

An apparatus for measuring ground-resistance leaked current is provided to measure a leaked current correctly by having a square wave conversion circuit, which converts a sine wave into a square wave, between a voltage detection circuit and a multiplying circuit. An apparatus for measuring leaked current includes an electric path(1), a voltage detection circuit(2), a current detection circuit(4), a current-voltage conversion circuit(5), a multiplying circuit, a low frequency pass filter(7) and a square wave conversion circuit(3). The voltage detection circuit detects a voltage of the electric path from the electric path of an object to be measured. The current detection circuit detects a mixed leaked current from the electric path to be measured. The current-voltage conversion circuit converts the mixed leaked current of the current detection circuit into a corresponding voltage. The multiplying circuit multiplies an output signal of the voltage detection circuit by an output signal of the current-voltage conversion circuit. The low frequency pass filter filters a low frequency from the output signal of the multiplying circuit. The square wave conversion circuit which converts a sine wave into a square wave is installed between the voltage detection circuit and the multiplying circuit.

Description

대지저항성 누전전류 측정기{Measuring instrument for an electric current leakage}Earth resistive leakage current measuring instrument {Measuring instrument for an electric current leakage}

도 1은 본 발명에 따른 누전전류 측정기를 도시한 도면,1 is a view showing a leakage current measuring instrument according to the present invention,

도 2는 합성 누전전류와 대지저항성 누전전류 및 대지용량성 누전전류 간의 상호 위상관계를 도시한 벡터 다이어그램,2 is a vector diagram showing a mutual phase relationship between a composite earth current, earth resistance earth current and earth capacitive earth current;

도 3은 본 발명에 따른 누전전류 측정기의 작동상태를 설명하기 위한 도면이다.3 is a view for explaining the operating state of the leakage current measuring device according to the present invention.

- 첨부도면의 주요 부분에 대한 용어 설명 --Explanation of terms for the main parts of the accompanying drawings-

1 ; 피측정 전선로, 2 ; 전압검출회로,One ; 2 wires to be measured; Voltage detection circuit,

3 ; 구형파변환회로, 4 ; 전류검출회로,3; Square wave conversion circuit, 4; Current detection circuit,

5 ; 전류전압변환회로, 6 ; 승산회로,5; Current-voltage conversion circuits; Multiplication Circuit,

7 ; 저주파통과필터.7; Low pass filter.

본 발명은 누전전류 측정기에 관한 것으로, 특히 간단한 회로구성으로 대지저항성 누전전류를 만족스럽게 측정할 수 있는 누전전류 측정기에 관한 것이다.The present invention relates to an earth leakage current meter, and more particularly, to an earth leakage current meter capable of satisfactorily measuring earth resistance earth current with a simple circuit configuration.

주지된 바와 같이, 교류전선로의 대지절연저항 또는 해당 교류전선로에 접속된 전기기기의 대지절연저항이 열화되면, 누전전류가 증가되어 전기화재 또는 감전사고 등이 발생할 수 있다.As is well known, when the earth insulation resistance of an AC line or the earth insulation resistance of an electric device connected to the AC line is deteriorated, a short circuit current may increase and an electric fire or an electric shock may occur.

따라서, 이러한 사고를 미연에 방지하기 위해서는 누전전류를 정확하게 측정해서 누전에 의한 전기화재 또는 감전사고 등을 예방해야 한다.Therefore, in order to prevent such an accident in advance, it is necessary to accurately measure the leakage current to prevent electric fire or electric shock due to the leakage.

일반적으로, 누전전류의 측정은, 피측정 전선로의 전력공급이 차단된 상태에서, 공지의 누전저항측정기를 이용하여 피측정 전선로와 대지 사이의 절연저항을 측정한다.In general, in the measurement of the leakage current, the insulation resistance between the wire under test and the earth is measured using a known earth resistance meter in a state where power supply to the wire under measurement is cut off.

그러나, 이처럼 누전저항측정기를 이용해서 누전전류를 측정하기 위해서는 반드시 피측정 전선로의 전력공급을 차단해야 하므로, 누전전류 측정작업이 상당히 번거롭고 불편할 뿐만 아니라, 각 세대에 대한 누전검사를 수행함에 있어서 방문 세대가 부재 중일 경우에는 누전전류 검출이 불가능하다.However, in order to measure the leakage current using the earth leakage resistance meter, it is necessary to cut off the power supply to the wire to be measured. Therefore, the earth leakage current measurement work is not only cumbersome and inconvenient, but also the visited generation in performing the earth leakage test for each generation. If is absent, leakage current detection is not possible.

이러한 문제를 해소하기 위해, 피측정 전선로의 전력공급을 차단하지 않은 상태에서, 공지의 클램프식 전류측정기를 이용하여 피측정 전선로의 누전전류를 측 정하는 방안이 제시되었지만, 이에 따른 누전전류 측정값은 대지저항성 누전전류와 대지용량성 누전전류를 합한 합성 누전전류이므로, 대지용량성 누전전류가 큰 경우에는 대지저항성 누전전류가 작더라도 합성 누전전류가 커져서 누전이 아님에도 불구하고 누전으로 판별되는 문제가 초래된다.In order to solve this problem, a method of measuring the leakage current to the wire under measurement using a known clamp-type current meter without interrupting the power supply to the wire under measurement has been proposed. Since the earth leakage current is the combined earth leakage current, which is the sum of the earth leakage current, the earth leakage current is large. Caused.

이에 최근에는 피측정 전선로의 전력공급을 차단하지 않은 상태에서, 피측정 전선로의 합성 누전전류와, 피측정 전선로의 전압을 측정한 후, 이를 매개로 대지저항성 누전전류를 검출하는 방안이 제시되었다.Recently, a method of detecting a ground fault current by measuring the synthesized leakage current of the cable under measurement and the voltage of the cable under measurement without interrupting the power supply to the cable under measurement.

이러한 누전전류 측정기는, 피측정 전선로로부터 측정된 합성 누전전류의 순시치와, 피측정 전선로로부터 측정된 전압의 순시치를 곱셈기를 매개로 직접 곱한 후, 이것을 다시 피측정 전선로 전압의 실효치로 나누어 대지저항성 누전전류를 검출하는 방식을 취하고 있다.Such a ground current measuring device directly multiplies the instantaneous value of the synthesized ground current measured from the cable under test with the multiplier by the instantaneous value of the voltage measured from the cable under test, and then divides it by the effective value of the voltage with the cable under test. The resistive leakage current is detected.

그러나, 이러한 누전전류 측정기는 곱셈기를 매개로 곱해진 값을 피측정 전선로 전압의 실효치로 나누어 대지저항성 누전전류를 검출하는 방식을 취하고 있어서, 누전전류 측정기의 회로 구조가 상당히 복잡하게 되는 문제가 초래된다.However, such a ground current measuring device divides the value multiplied by the multiplier by the effective value of the voltage to the wire to be measured and detects a ground resistive ground current. This causes a problem that the circuit structure of the ground current measuring device becomes quite complicated. do.

참고로, 피측정 전선로로부터 측정된 합성 누전전류의 순시치와, 피측정 전선로로부터 측정된 전압의 순시치를 곱셈기를 매개로 직접 곱하는 것은 어려움이 없지만, 이처럼 곱셈기를 매개로 곱해진 값으로부터 피측정 전선로 전압의 실효치로 나누어 대지저항성 누전전류를 검출하는 과정을 아날로그 방식으로 처리하기는 상당히 어렵다.For reference, it is not difficult to directly multiply the instantaneous value of the composite earth current measured from the cable under test and the instantaneous voltage of the voltage measured from the cable under test using a multiplier. The process of detecting earth-resistant leakage current by dividing the effective value of the furnace voltage is quite difficult by analog method.

이에 본 발명은 상기와 같은 문제를 해소하기 위해 발명된 것으로, 간단한 회로구성만으로도 대지저항성 누전전류를 만족스럽게 측정할 수 있는 누전전류 측정기를 제공함에 그 목적이 있다.Accordingly, the present invention has been invented to solve the above problems, and an object thereof is to provide an earth leakage current measuring device capable of satisfactorily measuring the earth resistance earth leakage current even with a simple circuit configuration.

상기와 같은 목적을 달성하기 위한 본 발명은, 피측정 전선로로부터 전선로 전압을 검출하는 전압검출회로와 ; 피측정 전선로로부터 합성 누전전류를 검출하는 전류검출회로 ; 전류검출회로로부터의 합성 누전전류를 이에 상응하는 전압으로 변환하는 전류전압변환회로 ; 전압검출회로로부터의 출력신호와, 전류전압변환회로로부터의 출력신호를 곱하는 승산회로 및; 승산회로로부터의 출력신호에서 저주파 성분만을 필터링하는 저주파통과필터를 갖춘 누전전류 측정기에 있어서, 상기 전압검출회로와 승산회로 사이에 정현파를 구형파로 변환하는 구형파변환회로가 보강되어진 것을 특징으로 하는 구조로 되어 있다.The present invention for achieving the above object is a voltage detection circuit for detecting a voltage from the cable line to the wire to be measured; A current detection circuit for detecting a synthesized leakage current from the cable under test; A current voltage conversion circuit for converting the composite leakage current from the current detection circuit into a corresponding voltage; A multiplication circuit for multiplying the output signal from the voltage detection circuit with the output signal from the current voltage conversion circuit; An earth leakage current measuring device having a low pass filter for filtering only low frequency components from an output signal from a multiplication circuit, wherein a square wave conversion circuit for converting a sine wave into a square wave is reinforced between the voltage detection circuit and the multiplication circuit. It is.

이하 본 발명을 첨부된 예시도면에 의거하여 상세히 설명한다.Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

본 발명에 따른 누전전류 측정기는, 도 1에 도시된 바와 같이, 피측정 전선로(1)로부터 전선로 전압을 검출하는 전압검출회로(2)와 ; 전압검출회로(2)로부터의 출력신호인 정현파를 구형파로 변환하는 구형파변환회로(3) ; 피측정 전선로(1) 로부터 합성 누전전류를 검출하는 전류검출회로(4) ; 전류검출회로(4)로부터의 합성 누전전류를 이에 상응하는 전압으로 변환하는 전류전압변환회로(5) ; 구형파변환회로(3)로부터의 출력신호와, 전류전압변환회로(5)로부터의 출력신호를 곱하는 승산회로(6) 및; 승산회로(6)로부터의 출력신호에서 저주파 성분만을 필터링하는 저주파통과필터(7)로 이루어진다.The earth leakage current measuring device according to the present invention, as shown in Fig. 1, the voltage detection circuit (2) for detecting the voltage from the cable line (1) to be measured; A square wave conversion circuit 3 for converting a sine wave which is an output signal from the voltage detection circuit 2 into a square wave; A current detection circuit 4 for detecting a synthesized leakage current from the cable line 1 to be measured; A current voltage converting circuit 5 for converting the synthesized leakage current from the current detecting circuit 4 into a corresponding voltage; A multiplication circuit 6 for multiplying the output signal from the square wave conversion circuit 3 with the output signal from the current voltage conversion circuit 5; It consists of a low pass filter 7 which filters only low frequency components in the output signal from the multiplication circuit 6.

본 실시예의 경우, 상기 전압검출회로(2)로는 피측정 전선로(1)에 접속되어 전선로의 전압을 분압하여 측정하는 공지의 전압검출회로를 적용하였다.In this embodiment, as the voltage detecting circuit 2, a well-known voltage detecting circuit connected to the wire 1 to be measured is used to measure voltage by dividing the voltage on the wire.

상기 전류검출회로(4)는 피측정 전선로(1)를 감싸면서 합성 누전전류를 검출하는 공지의 전류변성기를 적용하였다.The current detection circuit 4 employs a known current transformer that detects a composite leakage current while surrounding the wire 1 to be measured.

상기 구형파변환회로(3)나 전류전압변환회로(5), 승산회로(6) 및 저주파통과필터(7) 역시도 이미 널리 공지되어 공연 실시되고 있으므로, 이들에 대한 설명은 생략하기로 한다.Since the square wave converting circuit 3, the current voltage converting circuit 5, the multiplication circuit 6, and the low pass filter 7 are also well known and performed, the description thereof will be omitted.

도 2 및 도 3을 참조하여 본 발명에 따른 누전전류 측정기의 작동 상태를 설명해 보면 다음과 같다.Referring to Figures 2 and 3 to describe the operating state of the leakage current measuring device according to the present invention.

도 2를 참조해 보면, 대지절연선 누전전류 실효치(Ir)는 피측정 전선로 전압 실효치(V)와 위상이 같고, 대지용량성 누전전류 실효치(Ic)는 전선로 전압 실효치(V)보다 위상이 90°앞서며, 합성 누전전류 실효치(Ig)는 대지저항성 누전전류 실효치(Ir)와 대지용량성 누전전류 실효치(Ic)의 합으로서 피측정 전선로 전압 실효치(V)보다 위상이 θ만큼 앞선다는 것을 알 수 있다.Referring to FIG. 2, the earth leakage current effective value Ir is in phase with the voltage effective value V of the cable line under test, and the ground capacitive leakage current effective value Ic is out of phase with the voltage effective value V of the cable line. 90 ° ahead, the synthetic leakage current effective value (Ig) is the sum of the ground resistance leakage current effective value (Ir) and the ground capacitive leakage current effective value (Ic), indicating that the phase is ahead of the voltage effective value (V) by the measured wire. Able to know.

상기 피측정 전선로(1)의 전원이 고조파가 없는 정현파라면, 피측정 전선로 전압 순시치(v)와, 전압검출회로(2)로부터의 출력신호(v1)는 아래의 수학식 1 및 수학식 2와 같다.If the power supply of the wire under test 1 is a sine wave without harmonics, the voltage instantaneous value v of the wire under measurement and the output signal v1 from the voltage detection circuit 2 are represented by Equations 1 and 1 below. Equation 2

Figure 112007005958592-pat00017
Figure 112007005958592-pat00017

여기서, ω=2πf이고, f는 피측정 전선로의 전원 주파수이다.Here, ω = 2πf, and f is a power supply frequency to the wire to be measured.

Figure 112007005958592-pat00018
Figure 112007005958592-pat00018

여기서, K1은 전압검출회로(2)의 이득이다.Here, K1 is the gain of the voltage detection circuit 2.

또한, 상기 구형파변환회로(3)의 출력신호(v2)는, v1의 극성이 정(+)이면, 즉 0 < ωt < π 이면, v2는 + K2이고, v1의 극성이 부(-)이면, 즉 π < ωt < 2π 이면, v2는 - K2이다.Further, the output signal v2 of the square wave conversion circuit 3 has a positive polarity of v1, i.e., 0 <ωt <π, v2 is + K2, and a negative polarity of v1 is negative. That is, if π <ωt <2π, v2 is-K2.

한편, 상기 피측정 전선로(1)의 합성 누전전류가 고조파 없는 정현파라면, 피측정 전선로(1)의 합성 누전전류 순시치(ig)와, 전류검출회로(4)의 2차측 출력신 호(ih)와, 전류전압변환회로(5)의 출력신호(v3)는 아래의 수학식 3, 수학식 4, 수학식 5와 같다.On the other hand, if the synthesized leakage current of the wire under test 1 is a sine wave without harmonics, then the instantaneous current of the synthesized leakage current ig of the wire under measurement 1 and the secondary output signal of the current detection circuit 4 are measured. (ih) and the output signal v3 of the current voltage conversion circuit 5 are as shown in Equations 3, 4, and 5 below.

Figure 112007005958592-pat00019
Figure 112007005958592-pat00019

여기서, Ig는 합성 누전전류 실효치이고, θ는 피측정 전선로 전압 순시치(v)와 합성 누전전류 순시치(ig)와의 위상각이다.Here, Ig is the effective value of the composite leakage current, and θ is the phase angle between the voltage instantaneous value v and the synthesized leakage current instantaneous value ig.

Figure 112007005958592-pat00020
Figure 112007005958592-pat00020

여기서, K3는 전류검출회로(4)의 변류비이다.Here, K3 is a current ratio of the current detection circuit 4.

Figure 112007005958592-pat00021
Figure 112007005958592-pat00021

여기서, K4는 전류전압변환회로(3)의 이득이다.Here, K4 is the gain of the current voltage conversion circuit 3.

상기 승산회로(6)의 출력신호(p)는 구형파변환회로(3)의 출력신호(v2)와 전류전압변환회로(5)의 출력신호(v3)를 곱한 것으로서 아래의 수학식 6과 같다.The output signal p of the multiplication circuit 6 is multiplied by the output signal v2 of the square wave conversion circuit 3 and the output signal v3 of the current voltage conversion circuit 5, and is represented by Equation 6 below.

Figure 112007005958592-pat00022
Figure 112007005958592-pat00022

여기서, K5는 승산회로(6)의 이득이다.Here, K5 is the gain of the multiplication circuit 6.

따라서, 상기 구형파변환회로(3)의 출력신호(v2) 극성이 정(+)인 경우에는 아래의 수학식 7로, 부(-)인 경우에는 아래의 수학식 8로 표현될 수 있다.Therefore, when the polarity of the output signal v2 of the square wave conversion circuit 3 is positive (+), it may be represented by Equation 7 below, and in the case of negative (−), Equation 8 below.

Figure 112007005958592-pat00023
Figure 112007005958592-pat00023

Figure 112007005958592-pat00024
Figure 112007005958592-pat00024

상기 저주파통과필터(7)는 승산회로(6)의 출력신호(p)에 포함된 모든 고조파 신호를 걸러내기 때문에, 저주파통과필터(7)의 출력신호(S)는 출력신호(p)의 평균치에 해당하는 직류신호가 된다.Since the low pass filter 7 filters out all harmonic signals included in the output signal p of the multiplication circuit 6, the output signal S of the low pass filter 7 is the average value of the output signal p. It becomes a DC signal corresponding to.

따라서, 상기 저주파통과필터(7)의 출력신호(S)는 아래의 수학식 9와 같다.Therefore, the output signal S of the low pass filter 7 is expressed by Equation 9 below.

Figure 112007005958592-pat00025

Figure 112007005958592-pat00026

Figure 112007005958592-pat00027
Figure 112007005958592-pat00025
Figure 112007005958592-pat00026

Figure 112007005958592-pat00027

삭제delete

삭제delete

상기 수학식 9에서 K2,K3,K4,K5를 조정하여

Figure 112007005958592-pat00028
가 되도록 하면, 저주파통과필터(7)의 출력신호(S)는 아래의 수학식 10이 된다.By adjusting K2, K3, K4, K5 in the equation (9)
Figure 112007005958592-pat00028
In this case, the output signal S of the low pass filter 7 is expressed by Equation 10 below.

Figure 112007005958592-pat00029
Figure 112007005958592-pat00029

따라서, 상기 전압검출회로(2)를 피측정 전선로(1)에 접속하고, 상기 전류검출회로(4)으로 피측정 전선로(1)를 감싸면, 저주파통과필터(7)를 통해서 대지저항성 누전전류(Ir)가 출력된다.Therefore, when the voltage detection circuit 2 is connected to the wire under test 1 and the wire under test 1 is wrapped in the current detection circuit 4, the earth resistance leakage current is passed through the low pass filter 7. The current Ir is output.

도 3의 (a)는 전압검출회로(2)의 출력신호(v1)와, 구형파변환회로(3)의 출력신호(v2)를, 도 3의 (b)는 전류전압변환회로(5)의 출력신호(v3)를, 도 3의 (c)는 승산회로(6)의 출력신호(p)와 저주파통과필터(S)의 출력신호를 도시하고 있는데, 이를 참조해 보면 누전전류 측정기의 작동 상태를 가시적으로 파악할 수 있다.3A shows an output signal v1 of the voltage detection circuit 2 and an output signal v2 of the square wave conversion circuit 3, and FIG. 3B shows an output signal v2 of the current voltage conversion circuit 5. 3 (c) shows the output signal p of the multiplication circuit 6 and the output signal of the low pass filter S. Referring to this, the operating state of the ground current measuring instrument is shown. Can be visually identified.

우선, 도 3의 (a)에 도시된 바와 같이 정현파인 전압검출회로(2)의 출력신호(v1)는 구형파변환회로(3)에 의해 도 3의 (a)에 도시된 바와 같은 구형파로 변환된 후에 승산회로(6)로 입력된다.First, as shown in FIG. 3A, the output signal v1 of the sinusoidal voltage detection circuit 2 is converted into a square wave as shown in FIG. 3A by the square wave conversion circuit 3; After that, it is input to the multiplication circuit 6.

한편, 도 3의 (b)에 도시된 바와 같이 정현파인 전류전압변환회로(5)의 출력신호(v3)는 상기 전압검출회로(2)의 출력신호(v1)에 비해 θ만큼의 위상차를 보이며 승산회로(6)로 입력된다.On the other hand, as shown in (b) of FIG. 3, the output signal v3 of the sinusoidal current voltage conversion circuit 5 shows a phase difference of θ compared with the output signal v1 of the voltage detection circuit 2. It is input to the multiplication circuit 6.

상기 승산회로(6)는 구형파변환회로(3)의 출력신호(v2)와 전류전압변환회로(5)의 출력신호(v3)를 곱하여 도 3의 (c)에 도시된 바와 같은 출력신호(p)를 저주파통과필터(7)로 출력하고, 저주파통과필터(7)는 승산회로(6)의 출력신호(p)로부터 저주파 성분만을 필터링하여 최종적으로 도 3의 (c)에 도시된 바와 같은 출력신호(S)를 최종 출력한다.The multiplication circuit 6 multiplies the output signal v2 of the square wave conversion circuit 3 by the output signal v3 of the current voltage conversion circuit 5 to output an output signal p as shown in FIG. ) Is output to the low pass filter 7, and the low pass filter 7 filters only the low frequency components from the output signal p of the multiplication circuit 6 to finally output the output as shown in FIG. The signal S is finally output.

앞서 언급한 바와 같이, 상기 저주파통과필터(7)의 출력신호(S)가 바로 대지저항성 누전전류(Ir)이므로, 종래와 같이 승산회로(6)로부터의 출력값으로부터 피측정 전선로 전압의 실효치로 나누어서 대지저항성 누전전류를 검출하는 복잡한 과정을 수행할 필요가 전혀 없고, 누전전류 측정기의 회로 구성이 매우 단순화된다.As mentioned above, since the output signal S of the low pass filter 7 is the ground resistive leakage current Ir, the output value from the multiplication circuit 6 is converted from the output value from the multiplication circuit 6 to the effective value of the voltage to the wire under measurement. There is no need to perform a complicated process of detecting earth-resistant leakage current separately, and the circuit configuration of the leakage current meter is greatly simplified.

또한, 상기 저주파통과필터(7)의 출력신호(S)는 아날로그 신호이므로, 저주파통과필터(7) 이후의 회로구성은 아날로그 방식이나 디지털 방식 모두가 자유롭게 적용될 수 있다.In addition, since the output signal S of the low pass filter 7 is an analog signal, the circuit configuration after the low pass filter 7 may be freely applied to both an analog method and a digital method.

본 발명은 상기한 바와 같은 실시예에 한정되지 않고, 이하의 청구범위를 벗어나지 않는 한도 내에서, 보다 다양하게 변형 실시될 수 있음은 물론이다.The present invention is not limited to the embodiment as described above, and of course, various modifications can be made without departing from the scope of the following claims.

이상 상기한 바와 같은 본 발명에 따르면, 전압검출회로(2)와 전류검출회로(4), 전류전압변환회로(5), 승산회로(6) 및 저주파통과필터(7)를 갖춘 누전전류 측정기에 있어서, 전압검출회로(2)와 승산회로(6) 사이에 정현파를 구형파로 변환하는 구형파변환회로(3)가 보강되어진 것을 특징으로 하는 구조로 되어, 저주파통과필터(7)의 출력신호(S)가 대지저항성 누전전류(Ir)가 되도록 할 수 있으므로, 누전전류 측정기의 회로구성이 대폭 단순화되고, 정확한 누전 측정이 가능하게 되는 효과가 있다.According to the present invention as described above, an earth leakage current measuring device having a voltage detection circuit 2, a current detection circuit 4, a current voltage conversion circuit 5, a multiplication circuit 6 and a low-frequency filter 7 A square wave conversion circuit 3 for converting a sine wave into a square wave is reinforced between the voltage detection circuit 2 and the multiplication circuit 6, so that the output signal S of the low pass filter 7 is reduced. ) Can be a ground resistive leakage current Ir, which greatly simplifies the circuit configuration of the leakage current measuring instrument and enables accurate leakage measurement.

Claims (1)

피측정 전선로(1)로부터 전선로 전압을 검출하는 전압검출회로(2)와 ; 피측정 전선로(1)로부터 합성 누전전류를 검출하는 전류검출회로(4) ; 전류검출회로(4)로부터의 합성 누전전류를 이에 상응하는 전압으로 변환하는 전류전압변환회로(5) ; 전압검출회로(2)로부터의 출력신호와, 전류전압변환회로(5)로부터의 출력신호를 곱하는 승산회로(6) 및; 승산회로(6)로부터의 출력신호에서 저주파 성분만을 필터링하는 저주파통과필터(7)를 갖춘 누전전류 측정기에 있어서,A voltage detection circuit 2 for detecting a voltage from the wire 1 under test to the wire; A current detecting circuit 4 for detecting a synthesized leakage current from the cable line 1 to be measured; A current voltage converting circuit 5 for converting the synthesized leakage current from the current detecting circuit 4 into a corresponding voltage; A multiplication circuit 6 for multiplying the output signal from the voltage detection circuit 2 by the output signal from the current voltage conversion circuit 5; In an earth leakage current measuring device having a low pass filter (7) for filtering only low frequency components in an output signal from a multiplication circuit (6), 상기 전압검출회로(2)와 승산회로(6) 사이에 정현파를 구형파로 변환하는 구형파변환회로(3)가 보강되어진 것을 특징으로 하는 누전전류 측정기.And a square wave conversion circuit (3) for converting a sine wave into a square wave between the voltage detection circuit (2) and the multiplication circuit (6).
KR1020060073430A 2006-08-03 2006-08-03 Measuring instrument for an electric current leakage KR100771583B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020060073430A KR100771583B1 (en) 2006-08-03 2006-08-03 Measuring instrument for an electric current leakage

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020060073430A KR100771583B1 (en) 2006-08-03 2006-08-03 Measuring instrument for an electric current leakage

Publications (1)

Publication Number Publication Date
KR100771583B1 true KR100771583B1 (en) 2007-10-30

Family

ID=38816361

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020060073430A KR100771583B1 (en) 2006-08-03 2006-08-03 Measuring instrument for an electric current leakage

Country Status (1)

Country Link
KR (1) KR100771583B1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105548757A (en) * 2015-12-15 2016-05-04 东北电力大学 Tester for leakage protector
CN117590084A (en) * 2023-11-14 2024-02-23 国网江苏省电力有限公司南通市海门区供电分公司 Device and method for measuring grounding resistance of transmission line tower

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR19980018283A (en) * 1996-08-07 1998-06-05 윌리엄 에프. 마쉬 Process for producing nitrogen using double column and auxiliary low pressure separation zone
KR20020071166A (en) * 2001-03-05 2002-09-12 삼성전자 주식회사 Flag faraday for ion implanter apparatus
JP2003309153A (en) * 2002-04-08 2003-10-31 Micromanipulator Co Inc High resolution analytical probe station
JP2005227132A (en) * 2004-02-13 2005-08-25 Meidensha Corp Insulation condition monitoring apparatus and insulation condition monitoring method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR19980018283A (en) * 1996-08-07 1998-06-05 윌리엄 에프. 마쉬 Process for producing nitrogen using double column and auxiliary low pressure separation zone
KR20020071166A (en) * 2001-03-05 2002-09-12 삼성전자 주식회사 Flag faraday for ion implanter apparatus
JP2003309153A (en) * 2002-04-08 2003-10-31 Micromanipulator Co Inc High resolution analytical probe station
JP2005227132A (en) * 2004-02-13 2005-08-25 Meidensha Corp Insulation condition monitoring apparatus and insulation condition monitoring method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105548757A (en) * 2015-12-15 2016-05-04 东北电力大学 Tester for leakage protector
CN117590084A (en) * 2023-11-14 2024-02-23 国网江苏省电力有限公司南通市海门区供电分公司 Device and method for measuring grounding resistance of transmission line tower

Similar Documents

Publication Publication Date Title
KR100896091B1 (en) Measuring instrument for a resistive electric leakage current
CN102072999B (en) Connection testing device of electric energy metering device and using method thereof
KR20080093169A (en) Method of leakage current break and measurement leakage current use phase calculation
KR101407864B1 (en) Impedance calculation appratus and sinusoidal insulation monitoring apparatus comprising the voltage sensing
JP6127824B2 (en) Power conditioner system for photovoltaic power generation
WO2007004698A1 (en) Leakage current detection apparatus and leakage current detection method
WO2008072287A1 (en) Leakage current determining apparatus and leakage current determining method
KR100771939B1 (en) Measuring instrument for an electric current leakage
KR20180015566A (en) Leakage current measuring method and leakage current measuring apparatus
Tung et al. An Arduino-Based System for Monitoring and Protecting Overvoltage and Undervoltage.
KR100306569B1 (en) Apparatus for testing of ground resistance at activity state and therefor method
JP2005140532A (en) Device and method for calculating phase angle, device and method for detecting leakage current
KR100920153B1 (en) Measurement Device of leakage current ohmic value on power line And Method Thereof
JP2006234402A (en) Power source line measuring instrument
JP5020508B2 (en) Ground fault direction detector
KR100771583B1 (en) Measuring instrument for an electric current leakage
EP3133632B1 (en) Circuit breaker
JP2008058114A (en) Power meter
KR101075484B1 (en) Measurement Device of leakage current ohmic value on power line And Method Thereof
KR101157189B1 (en) Portable Direct Current Ground Detecting Apparatus and Detecting Method using the same
Cataliotti et al. A time-domain strategy for the measurement of IEEE Standard 1459-2000 power quantities in nonsinusoidal three-phase and single-phase systems
US20100106763A1 (en) RMS Metering Devices and Methods
JP6304956B2 (en) Resistance measuring device and resistance measuring method
JP2014211400A (en) Indirect ac megger measuring instrument and insulation resistance measuring method
JP4506959B2 (en) Insulation monitoring device

Legal Events

Date Code Title Description
A201 Request for examination
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
FPAY Annual fee payment

Payment date: 20111005

Year of fee payment: 5

FPAY Annual fee payment

Payment date: 20121024

Year of fee payment: 6

LAPS Lapse due to unpaid annual fee