KR100848681B1 - The installation Apparatus for optical current transformers - Google Patents

Abstract

The present invention relates to an apparatus for installing an optical current sensor, and more particularly, an optical current capable of measuring an accurate current at all times by fixing the sensing unit of the photocurrent sensor at the same position by any external impact or influence on a cable or busbar through which the current flows. It relates to a sensor installation device.

The photocurrent sensor installation device of the present invention is the above-mentioned value at a value given a first weight to the output value of the photocurrent sensor corresponding to the target cable among the plurality of photocurrent sensors corresponding to each of N (N is a natural number of two or more) wires In order to calculate the current flowing through the target cable by subtracting the weighted values of the respective photocurrent sensors corresponding to adjacent cables adjacent to the target cable, and using the subtracted values, the cable is fixed to the inner circumferential surface. A first fixing part having N sensor fixing parts for fixing an optical current sensor for measuring a current value of the cable on an outer circumferential surface thereof; A second fixing part having N cable fixing parts which face the cable fixing part of the first fixing part on an inner circumferential surface to fix the cable; And a coupling part for coupling the first fixing part and the second fixing part.

Optical current sensor, fixed, installed, measured.

Description

The installation Apparatus for optical current transformers}

1 is a configuration diagram of a photocurrent sensor installation device according to an embodiment of the present invention,

2 is a block diagram of a current measurement system according to an embodiment of the present invention;

3 is a configuration diagram of a photocurrent sensor according to an embodiment of the present invention;

4 is a circuit diagram illustrating a current calculator according to an embodiment of the present invention;

5 is a conceptual diagram of current measurement according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: First Government 110: Second Government

120: sensor fixing 130, 150: coupling portion

140: cable fixing

The present invention relates to an apparatus for installing an optical current sensor, and more particularly, an optical current capable of measuring an accurate current at all times by fixing the sensing unit of the photocurrent sensor at the same position by any external impact or influence on a cable or busbar through which the current flows. It relates to a sensor installation device.

The optical current sensor is fixedly installed on the cable or cable through which the sensing part flows at regular intervals. At this point, the optical current sensor detects the strength of the magnetic field generated by the current and modulates the intensity of the light passing through the sensing part in proportion to the strength of the magnetic field. Finally, as a device for measuring current through photoelectric conversion in a signal processing circuit, the sensor output varies considerably according to the installation method of the sensing unit.

The magnetic field of the current flowing cable is divided into a magnetostriction and a Faraday rotor method.

The magnetostrictive method coats the magnetostrictive material on the optical fiber or adheres or winds the optical fiber to the magnetostrictive material, so that the magnetostrictive material is deformed by the magnetic field generated by the flow of current, thereby inducing the optical fiber deformation. This method detects the strength of current through the magnitude of the phase difference.

The Faraday rotor method uses the property that the optical fiber itself or garnet, lead glass, etc. rotate the polarization plane by the magnetic field generated by the flow of current, and measure the magnetic field caused by the current through the change of the light intensity. It's a way to find the century.

The magnetostriction method or the method using the optical fiber Faraday rotator forms an optically closed loop by winding the Faraday rotator around the conductor that generates the magnetic field in an annular shape, so that it is not affected by the disturbing magnetic field in the adjacent phase or surroundings and accurately measures the current of the measuring conductor. This is possible. On the other hand, bulk photocurrent sensors that detect a magnetic field at a certain point of conductorism, such as garnet or lead glass, can be easily affected by the magnetic field of the adjacent phase, and the output value is greatly changed even by the slight variation of the installation position. . This causes serious errors in the measured values due to the phase-to-phase interference when measuring the three-phase current using the bulk photocurrent sensor.

On the other hand, the conventional photocurrent sensor installation method used an independent installation device that can be installed one by each phase. However, in case of using such a device, it is possible to keep the distance of the phase to be measured at all times, but it is difficult to install the distance from the adjacent phase at all times. Therefore, there is a problem that the adjustment of the signal processing circuit must be accompanied every time. Occurs.

Accordingly, the present invention is to solve the problems of the prior art, to provide an optical current sensor installation device that can be fixed to the sensing position of the photocurrent sensor in the same position by any external impact or influence on the current flow cable or busbar. There is a purpose.

In addition, another object of the present invention is to provide an optical current sensor installation apparatus capable of accurate current measurement by using an excellent insulating material.

An object of the present invention is adjacent to the target cable at a value given a first weight to the output value of the photocurrent sensor corresponding to the target cable among a plurality of photocurrent sensors respectively corresponding to N (N is two or more natural numbers) adjacent wires N cables fixed to the inner circumference of the cable in order to calculate a current flowing in the target cable by subtracting a value that is differently weighted to the output value of each photocurrent sensor corresponding to adjacent cables, and then using the subtracted value A first fixing part having a fixing part and having N sensor fixing parts for fixing an optical current sensor for measuring a current value of the cable on an outer circumferential surface thereof; A second fixing part having N cable fixing parts which face the cable fixing part of the first fixing part on an inner circumferential surface to fix the cable; And a coupling part for coupling the first fixing part and the second fixing part.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

1 is a block diagram of an optical current sensor installation device according to an embodiment of the present invention. The photocurrent sensor installation device according to Figure 1 can be used when the current of the three-phase cable (wire) is to be measured.

The photocurrent sensor installation device according to Figure 1 is processed in the shape of a cable according to the diameter and the distance between the cable of the first fixing part 100 covering the upper surface of the cable and the second fixing portion 110 to be covered with the same taste. The first fixing part 100 and the second fixing part 110 include a coupling part 130 and 150 and a sensor fixing part 120 to fix the photocurrent sensor.

The first fixing part 100 is provided with a cable fixing part 140 processed according to each cable diameter, the number of cables, the top of the cable fixing part 140 on the basis of the vertical center line of each cable fixing part 140. The sensor fixing part 120 is provided to be processed to fit the case size of the photocurrent sensor at a certain distance away from the. The second fixing part 110 is formed in a symmetrical form with the first fixing part 100 to match the diameter of the cable and to prevent the movement of up and down and left and right by fixing a plurality of cables at the same time.

The material of the photocurrent sensor installation device according to Figure 1 may use any one or more of MC Nylon, Bakelite and Teflon as an insulator having excellent insulation performance, the first fixing part 100 The coupling part 130 for assembling the second fixing part 110 may use a nonmagnetic material or an insulating material bolt, and preferably, may be made of a screw bolt or the like. The position of the sensor fixing part 120 on which the sensor is to be mounted on the first fixing part 100 is that the Faraday rotor 15, which is a magnetic field detecting element in the sensor part, must be located at the center of the cable, Is determined in consideration of the separation distance from, the sensor unit is designed to the exact size so as not to move into the sensor fixing part 120.

Figure 2 is a block diagram of a current measurement system according to an embodiment of the present invention. The current measuring system of the present invention includes a plurality of photocurrent sensors S ₁ to S ₃ and a computing device 200. The photocurrent sensors S ₁ to S ₃ detect magnetic fields formed around the corresponding cables 1, 2, and 3 and sense values corresponding to the magnitudes of the detected magnetic fields (for example, voltage values V ₁ to V _3). ) The photocurrent sensors S ₁ to S ₃ in the present invention correspond _one to _one to the plurality of adjacent cables 1, 2, and 3, respectively, and are installed at a position away from the corresponding cable (eg, the upper side of the cable). To detect the magnetic field formed by the current flowing through the cables 1, 2, 3.

As such, when the photocurrent sensors S ₁ to S ₃ are installed in a one-to-one correspondence to a plurality of adjacent cables 1, 2 and ₃ , the corresponding cables (targets) to each photocurrent sensor S ₁ to S ₃ are matched. In addition to the magnetic field (signal magnetic field) generated by the current flowing through the cable), the magnetic field (noise magnetic field) generated by the current flowing through the cables (adjacent cables) adjacent to the target cable is applied. Therefore, to accurately determine the magnitude of the current flowing through the target cable, the influence of the noise magnetic field must be corrected.

The computing device 200 receives the sensing values of the photocurrent sensors S ₁ to S ₃ and uses the same to adjacent cables adjacent to the cable at the sensing value of the photocurrent sensor corresponding to each cable (or a specific target cable). Calculate the magnitude of the current flowing through each cable (or a specific target cable) by removing the influence of the noise magnetic field, and output the corresponding voltage values (V ₁ ^c to V ₃ ^c ).

The computing device 200 receives all of the sensing values of the photocurrent sensors S ₁ to S _3, respectively, and removes the influence of the noise magnetic field by adjacent cables from the sensing value of the photocurrent sensor corresponding to the target cable. A plurality of current calculation units 210 to 230 are respectively provided to calculate currents flowing through and output corresponding voltage values V ₁ ^c to V ₃ ^c . That is, each of the current calculators 210 to 230 corresponds one-to-one to the plurality of adjacent cables 1, 2, and 3, and the corresponding specific cable becomes the target cable of the current calculator. Each of the current calculators 210 to 230 multiplies the sensing values V ₁ to V ₃ of the applied photocurrent sensors S ₁ to S ₃ by a predetermined weight and then corresponds to the photocurrent sensors installed on the target cable. By subtracting the value corresponding to the photocurrent sensors installed on the adjacent cable in, the strength of the current flowing through the target cable is accurately calculated. In this case, a weight multiplied by the sensing values of the photocurrent sensors S ₁ to S ₃ will be described later.

In the following description, the cable 1 is a target cable of the current calculation unit 210, the cable 2 is a target cable of the current calculation unit 220, and the cable 3 is a target cable of the current calculation unit 230. Assume

3 is a block diagram showing the configuration of any one (S ₁ ) of the photocurrent sensors (S ₁ to S ₃ ) used in one embodiment of the present invention. In the present invention, since the operation of the photocurrent sensor itself is not characteristic, the photocurrent sensor may use any kind of photocurrent sensor conventionally used. The photocurrent sensor S ₁ shown in FIG. 3 is also a photocurrent sensor commonly used, and therefore only the operation principle of the photocurrent sensor S ₁ shown in FIG. 3 will be briefly described.

The optical signal transmitted from the light source 11 and then transmitted through the input side optical fiber 12a becomes parallel light by the input side cell width lens 13a. The optical signal that becomes parallel light is linearly polarized by the input side PBS (Polarizing Beam Splitter, 14a) and then passes through the Faraday rotor 15. The Faraday rotor 15 rotates the polarization plane of linearly polarized light in proportion to the magnetic field generated by the current flowing through the cable 1. The degree of rotation of this polarization plane is converted to the intensity of light intensity by the output side PBS 14b, refracted by the 90 degree refraction prism 16, and focused by the output side cell width lens 13b. The optical signal focused on the cell width lens 13b is incident on the photodiode 17 through the output side optical fiber 12b and converted into an electrical signal. The signal processing circuit 20 processes the electric signal converted by the photodiode 17 and outputs a voltage value proportional to the magnitude of the current flowing in the cable 1 as a sensing value for the cable 1.

4 is a circuit diagram illustrating the configuration of the current calculators 210 to 230 of FIG. 1 in more detail. Each current calculation unit 210 to 230 includes a primary correction unit 212, a secondary correction unit 214, and an output correction unit 216. The primary correction unit 212 corrects the influence of the noise magnetic field of the adjacent cable 2 on the output voltage of the photoelectric current sensor S ₁ corresponding to the target cable 1. To this end, the first correction unit 212 multiplies the output voltage of the photocurrent sensor S ₁ by a predetermined first weight, and then, at that value, the output voltage of the photocurrent sensor S ₂ corresponding to the adjacent cable 2. The value multiplied by the second weight is subtracted. The primary compensator 212 includes OP amplifiers OP1, OP2, and OP4, resistors R1 to R5, and variable resistors VR1 and VR2 as shown in FIG.

The secondary correction unit 214 corrects the influence of the noise magnetic field of the adjacent cable 3 on the output voltage of the primary correction unit 212. To this end, the secondary corrector 214 subtracts the output voltage of the primary corrector 212 from the output voltage of the photocurrent sensor S ₃ multiplied by a third weight. The secondary correction unit 214 includes OP amplifiers OP3 and OP5, resistors R6 to R9, and variable resistor VR3.

The output corrector 216 adjusts the magnitude of the output voltage of the secondary corrector 214 and outputs a voltage value corresponding to the magnitude of the current of the target cable 1. The output compensator 216 includes an OP amplifier OP6, a resistor R10 and a variable resistor VR4.

In FIG. 4 described above, the case in which three adjacent cables 1, 2, and 3 are illustrated as an example is provided with only two correction units 212 and 214, and the number of adjacent cables is proportional to the increasing number. The configuration of the correction unit may be added.

5 is a conceptual diagram illustrating a current measuring method according to an exemplary embodiment of the present invention, which is an example of a method of measuring a current of a three-phase cable using an optical current sensor. It is to explain how to measure the magnitude of the current flowing through the cable under measurement by correcting the influence of the noise magnetic field.

Each photocurrent sensor S ₁ to S ₃ corresponds one-to-one with adjacent cables 1, 2 and 3, and is installed at a predetermined interval on the corresponding cable. At this time, the distance between the photocurrent sensor (S ₁ ) and each cable (1, 2, 3) is r ₁₁ , r ₁₂ , r ₁₃ , respectively, and between the photocurrent sensor (S ₂ ) and each cable (1, 2, 3) The distances are r ₂₁ , r ₂₂ , and r ₂₃ , respectively, and the distances between the photocurrent sensor S ₃ and the cables 1, 2, and 3 are respectively r ₃₁ , r ₃₂ , and r ₃₃ .

The photocurrent sensors for measuring the currents in cables 1, 2 and 3 are assigned to S ₁ , S ₂ and S ₃ respectively, but each photocurrent sensor is applied not only to the magnetic field by the current of the measuring cable but also to the magnetic field by the other two adjacent cables. Will be affected by the distance and installation angle. For example, the output of the S ₁ sensor should measure only the magnetic field generated by cable 1 at r ₁₁ distance for accurate current measurement, but will be interfered by the magnetic field by cable 2 at r ₁₂ distance and cable 3 at r ₁₃ distance. do. In order to remove such an interference magnetic field, a separate calculation unit for removing the portion corresponding to the strength of the interference signal according to the separation distance and the separation angle from the output signal of the S ₁ sensor is applied in the signal processing circuit 20 and finally. Only the magnetic field by cable 1 should be measured. In order to perform these operations correctly, the position must be fixed between the three-phase cable and the corresponding sensors. Therefore, the installation apparatus for the photocurrent sensor of the present invention enables the measurement system to remove the interfering magnetic field on the adjacent surface by fixing the distance between the cables as well as the relative positions between the cables and the sensors.

,

,

는 각각 위상차가 120도 나는 통상의 3상 전류이므로 다음 수학식1과 같이 표현할 수 있다.The method of calculating the magnitude of the current flowing through each cable (1, 2, 3) by correcting the influence of the noise magnetic field by adjacent cables in each cable (1, 2, 3) is as follows. Current flowing through each cable (1, 2, 3)

,

,

Since is a normal three-phase current each phase difference 120 degrees can be expressed as the following equation (1).

[Equation 1]

,

,

,

,

,

는 각각 전류 I₁, I₂의 진폭, ω는 각진동수, t는 시간을 나타낸다. 이때, 두 전류 I₁, I₂의 각진동수 ω를 같게 놓은 것은 통상 사용하는 교류의 주파수가 60 Hz 또는 50 Hz 등으로 정해져 있기 때문이다. 물론, 직류의 경우에도 본 발명은 성립하며, 전류를 교류로 한 것은 보다 일반적인 경우를 생각하기 위해서이다.From here,

,

Are the amplitudes of currents I ₁ and I ₂ , ω is the angular frequency, and t is the time. At this time, the angular frequency ω of the two currents I ₁ and I ₂ is set to be the same because the frequency of alternating current used is usually set at 60 Hz or 50 Hz. Of course, the present invention holds even in the case of direct current, and the reason why the current is alternating current is to consider a more general case.

,

,

)는 각각 다음 수학식2와 같다.At this time, each of the photocurrent sensors S ₁ to S ₃ is generated by the current flowing through the cable (adjacent cable) as well as the magnetic field (signal magnetic field) generated by the current flowing through the corresponding cable (target cable). A magnetic field (noise field) is applied at the same time. Therefore, the magnetic field applied to each photocurrent sensor S ₁ to S ₃ by the current flowing through the cables 1, 2, 3 (

,

,

Are each as shown in Equation 2 below.

[Equation 2]

,

,

는 각각 광전류센서(S₁ ∼ S₃)에 인가되는 자계에 의해 얻어진 전압 즉 광전류센서(S₁ ∼ S₃)에서 출력되는 센싱값(센싱전압)을 나타낸다. 수학식 2는 앙페르의 법칙을 이용한 것으로, 단위계로는 cgs 단위계를 사용했다. 즉, 자계의 단위는 Oe, 전류의 단위는 A, 거리의 단위는 cm이다.here

,

,

Represents the sensed value (sense voltage) which is output from the photo current that is a voltage sensor (S ₁ ~ S ₃₎ obtained by the magnetic field applied to the respective photoelectric sensor (S ₁ ~ S _3). Equation 2 uses Enfer's law, and cgs is used as the unit system. That is, the unit of magnetic field is Oe, the unit of current is A, and the unit of distance is cm.

,

,

(단,

,

,

, 여기서,

,

와

,

는 각각

,

,

의 진폭 및 위상)라고 하면 위와 같은 식이 성립한다.Since the photocurrent sensors S ₁ to S ₃ typically detect a magnetic field due to the current flowing through the corresponding cable by outputting a voltage proportional to the magnetic field, the photocurrent sensor S ₁ when a magnetic field as shown in Equation 2 is applied. ~ S ₃₎ the output voltage (sensed value) obtained from the respective

,

,

(only,

,

,

, here,

,

Wow

,

Are each

,

,

Is the same as above.

,

,

의 계수들

,

,

,

,

,

,

,

,

은 r₁₁, r₁₂, r₁₃, r₂₁, r₂₂, r₂₃, r₃₁, r₃₂, r₃₃을 실측하여 그 값을 수학식 2에 대입하여 구할 수도 있으나, 본 실시예에서는 보다 정확한 측정을 위해 수학식 2에서

,

,

앞의 계수들

,

,

,

,

,

,

,

,

을 다음과 같은 방법을 이용하여 실험적으로 구하였다.In equation (2)

,

,

Coefficients

,

,

,

,

,

,

,

,

R ₁₁ , r ₁₂ , r ₁₃ , r ₂₁ , r ₂₂ , r ₂₃ , r ₃₁ , r ₃₂ , and r ₃₃ may be measured and substituted by Equation 2, but in the present embodiment, for more accurate measurement,

,

,

Preceding coefficients

,

,

,

,

,

,

,

,

Was obtained experimentally using the following method.

가 흐르도록 하고 다른 케이블(2, 3)에는 전류가 흐르지 않도록 한 상태(

=0,

=0)에서, 각 광전류센서(S₁ ∼ S₃)에서 센싱된 값

,

,

을 구한다. 다음에, 수학식 2에

값을 대입하고

,

값으로는 0을 대입한다. 그리고,

,

,

값으로는 각 광전류센서(S₁ ∼ S₃)의 출력값(센싱값)을 대입한다. 이로부터, 다음과 같이

,

,

값을 구할 수 있다.First, the current whose value is known only to cable 1

Current flows in the other cable (2, 3)

= 0,

= 0), the value sensed by each photocurrent sensor S ₁ -S ₃

,

,

Obtain Next, in equation (2)

Assigning a value

,

Enter 0 for the value. And,

,

,

Value is substituted into the output value (sensed value) of each of photoelectric sensors (S ₁ ~ S _3). From this,

,

,

You can get the value.

[Equation 3]

,

,

,

,

가 흐르도록 하고, 케이블(1, 3)에는 전류가 흐르지 않도록 한 상태(

=0,

=0)에서, 각 광전류센서(S₁ ∼ S₃)에서 센싱된 값

,

,

을 구한다. 다음에, 수학식 2에

값을 대입하고

,

값으로는 0을 대입한다. 그리고,

,

,

값으로는 각 광전류센서(S₁ ∼ S₃)의 출력값(센싱값)을 대입한다. 이로부터, 다음과 같이

,

,

값을 구할 수 있다.Similarly, current only in cable 2

Is allowed to flow, and currents do not flow through the cables (1, 3) (

= 0,

= 0), the value sensed by each photocurrent sensor S ₁ -S ₃

,

,

Obtain Next, in equation (2)

Assigning a value

,

Enter 0 for the value. And,

,

,

Value is substituted into the output value (sensed value) of each of photoelectric sensors (S ₁ ~ S _3). From this,

,

,

You can get the value.

[Equation 4]

,

,

,

,

가 흐르도록 하고, 케이블(1, 2)에는 전류가 흐르지 않도록 한 상태(

=0,

=0)에서, 각 광전류센서(S₁ ∼ S₃)에서 센싱된 값

,

,

을 구한다. 다음에, 수학식 2에

값을 대입하고

,

값으로는 0을 대입한다. 그리고,

,

,

값으로는 각 광전류센서(S₁ ∼ S₃)의 출력값(센싱값)을 대입한다. 이로부터, 다음과 같이

,

,

값을 구할 수 있다.Finally, the current only in the cable (3)

Is allowed to flow, and no current flows through the cables (1, 2) (

= 0,

= 0), the value sensed by each photocurrent sensor S ₁ -S ₃

,

,

Obtain Next, in equation (2)

Assigning a value

,

Enter 0 for the value. And,

,

,

Value is substituted into the output value (sensed value) of each of photoelectric sensors (S ₁ ~ S _3). From this,

,

,

You can get the value.

[Equation 5]

,

,

,

,

,

,

에 관하여 다시 정리하면 다음과 같은 수학식 6을 얻을 수 있 다.After substituting the values of Equations 3 to 5 into Equation 2,

,

,

To recapitulate with respect to Equation 6 can be obtained.

[Equation 6]

,

,

앞의 계수는 인접 케이블으로부터의 잡음자계를 제거하기 위한 가중치를 나타내고,

,

,

는 인접 케이블으로부터의 잡음자계를 제거한 후 얻어지는 보정된 출력 값을 의미한다.here

,

,

The former coefficient represents the weight for removing the noise magnetic field from the adjacent cable,

,

,

Denotes the corrected output value obtained after removing the noise magnetic field from adjacent cables.

에 대한 연산이 수행되도록 설계된 회로로서, 각 가변저항 VR1 ∼ VR3의 크기를 적절히 조절하여 광전류센서(S₁ ∼ S₃)로부터 인가되는 전압

,

,

에 각각 가중치 10.700, 가중치 2.510, 가중치 0.662가 곱해지도록 한다. 이로써, 수학식 6에서와 같이 케이블(1)에 흐르는 전류

의 크기를 정확히 구할 수 있게 된다.The circuit diagram of the current calculator 210 of FIG. 4 is shown in Equation 6.

A circuit designed to perform the calculation of the voltage, and the voltage applied from the photocurrent sensors S ₁ to S ₃ by appropriately adjusting the sizes of the variable resistors VR1 to VR3.

,

,

Are multiplied by 10.700, 2.510 and 0.662 respectively. Thus, the current flowing through the cable 1 as shown in equation (6)

You can get the exact size of.

를 구하기 위한 전류계산부(210)의 회로구성만을 도시하고 있으나, 도 4와 동일한 구조를 가지며 수학식 6에서 전류

,

에 대한 전압

,

의 계수에 맞게 가변저항 VR1 ∼ VR3의 크기를 적절히 조절하여 전류계산부(220, 230)를 형성함으로써 케이블(2, 3)에 흐르는 전류

,

도 역시 정확하게 구할 수 있다. 또한, 도 4의 회로구성은 단지 본 발명의 일실시예를 나타낸 것으로서, 상술된 보정기능을 수행할 수 있다면 어떠한 형태로 회로를 구성하여도 무방하다.4 is a view illustrating the operation device 200 of FIG. Current flowing through the cable 1

Although only the circuit configuration of the current calculation unit 210 for obtaining is shown, it has the same structure as in FIG.

,

Voltage for

,

The currents flowing through the cables 2 and 3 are formed by forming the current calculating units 220 and 230 by appropriately adjusting the sizes of the variable resistors VR1 to VR3 according to the coefficient of.

,

Can also be accurately obtained. In addition, the circuit configuration of FIG. 4 shows only one embodiment of the present invention, and the circuit may be configured in any form as long as the above-described correction function can be performed.

It was confirmed through the following experiment that the circuit constructed as described above removes the noise magnetic field caused by the adjacent cables and outputs a voltage proportional to the current flowing through each cable.

,

,

가 흐르도록 하였을 때, 임의의 시각 t₁, t₂에서 각 광전류센서(S₁ ∼ S₃)의 출력전압(센싱값)

,

,

을 이용하여 구한 전류값

,

,

과, 본 발명에 따른 보정방법을 적용한 연산장치(200)의 각 전류계산부(210 ∼ 230)의 출력전압

,

,

을 이용하여 구한 전류값

,

,

및 표준 CT에 의해 얻어지는 전류 값

,

,

을 비교한 값을 나타낸다.Table 1 shows three-phase currents of 120 degrees in each of cables 1, 2, and 3 using standard CT and oscilloscopes (not shown) that are not affected by the magnetic field of adjacent cables.

,

,

Output voltage (sensing value) of each photocurrent sensor S ₁ to S ₃ at arbitrary times t ₁ and t ₂

,

,

Current value obtained using

,

,

And output voltages of the current calculation units 210 to 230 of the calculation device 200 to which the correction method according to the present invention is applied.

,

,

Current value obtained using

,

,

And current values obtained by standard CT

,

,

The value is compared.

TABLE 1

Time I _1a I _2a I _3a I _1b I _2b I _3b I _1c I _2c I _3c t ₁ -83.45 -15.19 15.48 -865.0 -0.196 259.9 -866 0 259.8 t ₂ -91.93 3.75 9.13 -999.1 249.9 150.1 -1000 250 150

,

,

은 작은 오차범위 내에서 표준 CT에 의해 얻어지는 전류값

,

,

과 잘 일치하는 것을 알 수 있다. 반면에, 광전류센서(S₁ ∼ S₃)의 출력전압(센싱값)

,

,

을 이용하여 구한 전류값

,

,

은 인접 케이블에 의한 잡음 자계로 인하여 표준 CT에 의해 얻어지는 전류값

,

,

과 많은 차이가 나고 있음을 알 수 있다.As shown in Table 1, the current value from which the noise magnetic field is removed by the computing device 200 of the present invention.

,

,

Is the current value obtained by standard CT within a small error range

,

,

It can be seen that it matches well with. On the other hand, the output voltage (sensing value) of the photocurrent sensors S ₁ to S ₃

,

,

Current value obtained using

,

,

Is the current value obtained by standard CT due to noise magnetic field by adjacent cables

,

,

You can see that there are many differences.

In addition, the current measuring method according to the present invention can be applied not only to a normal three-phase current having a phase difference of 120 degrees as shown in Table 1, but also to a case of an accident current in which the phase difference between three phases is not 120 degrees.

,

간에 30도 위상차가 나고,

,

간에는 120도 위상차이며,

,

간에는 150도 위상차가 나는 경우에 대해, 위와 같은 방법으로 전류를 측정한 결과, 표 2와 같이 전류값

,

,

이 작은 오차범위 내에서 전류값

,

,

과 잘 일치했다.For example, as shown in Equation 7 below.

,

30 degrees out of phase between the liver,

,

120 degrees out of phase,

,

As a result of measuring the current in the same manner as above for the case where the phase difference is 150 degrees between

,

,

Current value within this small error range

,

,

And well matched.

[Equation 7]

,

,

,

,

TABLE 2

Time I _1a I _2a I _3a I _1b I _2b I _3b I _1c I _2c I _3c t ₁ -46.85 -6.01 19.92 -499.4 -0.14 259.9 -500 0 259.8 t ₂ 8.07 28.75 21.25 0.12 249.98 150.12 0 250 150

In addition, the current measuring method according to the present invention was effective not only in the case where the phase difference between the three phases is different, but also in relation to the current at the time of failure in which the frequencies of the three phases do not match.

,

간에 30도 위상차가 나고,

,

간에는 120도 위상차이며,

,

간에는 150도 위상차가 나며,

은 주파수가 30 Hz이고,

와

의 주파수는 60 Hz인 경우에 대해, 위와 같은 방법으로 보정하여 측정한 결과, 표 3과 같이 전류값

,

,

이 작은 오차범위 내에서 전류값

,

,

과 잘 일치했다.For example, as shown in Equation 8 below.

,

30 degrees out of phase between the liver,

,

120 degrees out of phase,

,

The liver is 150 degrees out of phase,

Has a frequency of 30 Hz,

Wow

For the case of the frequency of 60 Hz, as measured by the above-described method, the current value as shown in Table 3

,

,

Current value within this small error range

,

,

And well matched.

[Equation 8]

,

,

,

,

,

,

,

,

TABLE 3

Time I _1a I _2a I _3a I _1b I _2b I _3b I _1c I _2c I _3c t ₁ 53.15 19.00 32.04 499.8 0.03 259.8 500 0 259.8 t ₂ -46.85 -6.01 19.92 -499.4 -0.14 259.9 -500 0 259.8

,

,

, …,

이 흐른다고 가정한다.In the above-described embodiment, a case in which three cables are adjacent to each other is described, but generalizing this to n adjacent cables is as follows. Numbering n cables, 1, 2, 3,... , cable n, and the current given to each of these cables

,

,

,… ,

Assume this flows.

[Equation 9]

       .

       .

       .

,

,

, ...,

는, 앞에서와 같이, 각각 전류

,

,

, …,

의 진폭이며,

는 각진동수, t는 시간,

,

,

, …,

는 전류

,

,

, ...,

의 위상을 나타낸다.here,

,

,

, ...,

As before, respectively the current

,

,

,… ,

Is the amplitude of

Is the angular frequency, t is the time,

,

,

,… ,

Current

,

,

, ...,

Indicates the phase.

In addition, the distances between the photocurrent sensors S ₁ to S _n and the cables 1, 2, 3, ..., n are respectively determined.

,

,

, ...,

,

,

, ...,

,

,

, ...,

,

,

, ...,

,

,

, ...,

,

,

, ...,

        .

        .

        .

,

,

, ...,

,

,

, ...,

It is called. Then, the magnetic field applied to each photocurrent sensor S ₁ to S _n is as follows.

[Equation 10]

                      .

                      .

                      .

,

,

, ...,

는 각각 광전류센서(S₁ ∼ S_n)로부터 얻어지는 출력전압(센싱값)이다. 수학식 10의

에 대한 식에서 우변 첫 번째항은 측정하고자 하는 케이블의 전류에 의한 신호자계를 나타내며, 나머지 항은 인접한 케이블으로부터의 잡음자계를 나타낸다.here,

,

,

, ...,

Are output voltages (sensing values) obtained from the photocurrent sensors S ₁ to S _n , respectively. Of equation (10)

In the equation, the first term on the right side represents the signal magnetic field by the current of the cable to be measured, and the remaining term represents the noise magnetic field from the adjacent cable.

,

,

, ...,

에 대해 풀면 다음식과 같은 결과를 얻는다.The system of equations (10)

,

,

, ...,

Solving for gives the following result:

[Equation 11]

                 .

                 .

                 .

                 .

                 .

                 .

는 연립방정식인 수학식 10을 풀어서 얻어지는 상수로서, 측정하고자 하는 케이블 위에 설치된 광전류센서의 출력값과 인접한 케이블 위에 설치된 광전류센서들로부터 얻어지는 출력값을 이용하여, 인접 케이블에 의한 잡음자계를 제거 하기 위한 가중치의 의미를 지닌다.here

Is a constant obtained by solving Equation 10, which is a system of equations. Has meaning.

,

,

, …,

값을 정밀하게 구할 수 있다.Accordingly, if the calculated output value of each photocurrent sensor is calculated by multiplying the output value obtained from each photocurrent sensor by the weight as shown in the right side of Equation 11, the noise magnetic field by the adjacent cable is removed.

,

,

,… ,

The value can be obtained precisely.

Although the present invention has been shown and described with reference to the preferred embodiments as described above, it is not limited to the above embodiments and those skilled in the art without departing from the spirit of the present invention. Various changes and modifications will be possible.

Therefore, the photocurrent sensor installation device of the present invention can be fixed in the same position by any external impact or influence on the sensing portion of the photocurrent sensor on the cable or busbar through which the current flows, it is possible to accurately measure the current.

In addition, the optical current sensor installation device of the present invention can be used to make a more accurate current measurement by using an excellent insulating material.

Claims (4)

N-N (N is a natural number of two or more) of the plurality of photocurrent sensors corresponding to each of the wires to the adjacent cable adjacent to the target cable at a value given a first weight to the output value of the photocurrent sensor corresponding to the target cable In order to calculate the current flowing through the target cable by subtracting the respective weighted values to the output values of the respective photocurrent sensors and using the subtracted values, A first fixing part having N cable fixing parts for fixing cables on an inner circumferential surface, and N sensor fixing parts fixing an optical current sensor for measuring a current value of the cable on an outer circumferential surface; A second fixing part having N cable fixing parts which face the cable fixing part of the first fixing part on an inner circumferential surface to fix the cable; And Coupling unit for combining the first fixing part and the second fixing part Optical current sensor installation device comprising a. The method of claim 1, The sensor fixing part is an optical current sensor installation device is provided on the outer peripheral surface of the first fixing part. The method of claim 2, The first fixing part and the second fixing part is MC nylon, Bakelite (Bakelite) and Teflon (Teflon) of any one of the optical current sensor installation device. The method of claim 3, wherein The coupling unit is a photocurrent sensor installation device made of a non-magnetic material or an insulating material bolt.

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