KR20190143233A - Power cable structure with conductive liquid - Google Patents

Abstract

The present invention relates to a power cable structure with a conductive liquid as a medium. More specifically, the present invention relates to a power cable structure with a conductive liquid as a medium which can transmit power by using a conductive liquid comprising a carbon nanotube, graphite, and a surfactant. To solve above-mentioned existing problems, the power is transmitted without using an existing specific metal conductor, utilization of a metallic mineral is minimized, waste of resources is prevented, and a utilization rate decrease of the conductor caused by a skin effect appearing when using the metal conductor can be minimized so as to minimize the waste of the resources in accordance with power transmission and propose a power transmitting method by using various mediums, thereby leading a future power transmitting technology field.

Description

Power cable structure with conductive liquid as a medium

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power cable structure comprising a conductive liquid as a medium, and more particularly, to a power cable comprising a conductive liquid capable of transferring electric power using a conductive liquid including carbon nanotubes, graphite, and a surfactant. It is about a structure.

Generally, metal conductors, such as copper and aluminum, are used as a conductor for electric power transmission. The current flow in the metal conductor is a phenomenon caused by the flow of free electrons in the metal. The vibration of the metal lattice is caused by the collision of electrons with the metal atoms, and heat is generated. Increasing the probability of collision increases resistance.

In addition, due to the characteristics of the metal, the thermal expansion and the hardness ratio according to the characteristics of the solid has a hardness ratio according to the characteristics of the solid, so it is difficult to work because it is resistant to bending and bending, and if there are excess free electrons in the metal conductor, the electrons are mutually rejected. Since the electrons eventually collect on the surface, a skin effect occurs in which a current flows only in the skin of the conductor, and thus the utilization rate of the conductor as an energy transfer medium is lowered.

Republic of Korea Patent Registration 10-1867224 Republic of Korea Patent Publication 10-2016-0121873

The present invention is to solve the conventional problems as described above, to prevent the waste of resources by transmitting power and minimizing the use of metal minerals without using a specific metal conductor of the prior art, due to the skin effect that appears when using a metal conductor By minimizing the reduction of the utilization rate of the conductor, it minimizes the waste of resources due to the power transfer, and proposes a power transmission method using a variety of media to provide a power cable structure with a conductive liquid medium that can lead the field of power transmission technology in the future The purpose is.

In order to achieve the above object, a power cable structure having a conductive liquid as a medium according to the present invention has a conductive liquid having a conductivity to transfer electric power, and a hollow portion therein to allow the conductive liquid to be injected and received therein. A cable including an inner shell formed and having an insulation, and an outer shell formed to surround the outer side of the inner shell; And an electrode unit coupled to both ends of the cable to prevent leakage of the conductive solution to the outside, and sealing the hollow part of the cable, and having an electrical conductivity to be in contact with the conductive solution to transfer power to the conductive solution. Characterized in that.

Screw grooves are formed on the inner circumferential surfaces of both end portions of the endothelium, respectively, and the electrode portions are connected to end portions of one endothelial end and the other endothelial end, respectively, connecting electrode portions connecting the cables to each other, and ends of end-side cables. And a terminal electrode portion coupled to the connecting electrode portion, wherein the connecting electrode portion extends a predetermined length from one side and the other side of the connecting electrode main body facing each other so as to be screwed into the threaded groove of the inner shell, respectively. A first connection screw coupling portion and a second connection screw coupling portion each of which has threads formed on an outer circumferential surface thereof, wherein the terminal electrode portion is one of the end electrode body so as to be screwed into the cylindrical end electrode body and the endothelial screw groove; It characterized in that it comprises a terminal screw coupling portion extending from the side to a predetermined length and the thread formed on the outer peripheral surface.

The conductive solution is characterized in that it comprises carbon nanotubes, graphite, surfactant.

Since the electric power cable structure using the conductive liquid medium according to the present invention uses the conductive liquid as a medium for transmitting electric power, energy transfer as alternating current power is not carried by the flow of free electrons in the medium, but rather in the dielectric material due to the change of the sign of the electric field. Since it appears as a movement between the poles due to the alignment of the charge, there is little exothermic phenomenon such as electron transfer in the solid, and according to the conditions of the medium, it can transfer the maximum current or only the voltage and minimize the flow of the current, thereby minimizing the loss due to the power There are advantages to it.

1 is a perspective view of a power cable structure having a conductive liquid as a medium according to the present invention.
FIG. 2 is a cross-sectional view of a power cable structure having a conductive liquid shown in FIG. 1 as a medium; FIG.
3 is a conceptual diagram of a power cable structure having a conductive liquid as a medium according to the present invention.
4 is a circuit diagram of a power cable structure having a conductive liquid as a medium according to the present invention;
5 is a circuit diagram of a power cable structure having a conductive liquid as a medium according to the present invention;

Hereinafter, a power cable structure 1 having a conductive liquid as a medium will be described in detail with reference to the accompanying drawings.

1 to FIG. 1 show a power cable structure 1 with a conductive liquid according to the invention. 1 to FIG. 1, a power cable structure 1 having a conductive liquid as a medium according to the present invention includes a cable 10 and electrode portions 20 and 30.

The cable 10 has a conductive conductive liquid 101 that is electrically conductive to transfer power, a hollow portion formed therein to allow the conductive liquid 101 to be introduced and received therein, and an inner layer having an insulating property and an outer side of the inner skin. It is configured to include a shell 104 formed to surround.

The conductive liquid 101 constituting the electric power cable structure having a conductive liquid medium according to the present invention is preferably applied to the external environment without vaporizing or boiling at 100 ° C. or higher and not freezing at −40 ° C. In addition, the conductivity of the conductive liquid is preferably similar to copper (Cu) or at least 60% based on at least the conductivity of copper.

Metal nanoparticles (Cu, Ag, Al) may be used as the material satisfying these conditions, but a liquid mixed with various materials to prevent them from sinking in a solvent or having a problem in stability of a solution Apply a colloid.

The conductive liquid 101 constituting the electric power cable structure having a conductive liquid as a medium according to the present invention applies to carbon nanotubes, graphite and surfactants.

Carbon nanotubes (CNTs) are made of carbon only, and a graphene sheet in which a single carbon atom is bonded to three other carbon atoms adjacent to each other in a hexagonal honeycomb pattern is seamlessly rolled to form a tube shape.

Since carbon atoms forming carbon nanotubes have an electron array of 1s ² 2s ² 2p ² , one of the 2s orbitals is transferred to a 2p orbital function to form a covalent bond. In the graphite crystal structure, one carbon atom forms a strong σ bond represented by sp ² on a plane with three adjacent carbon atoms, and an electron having a remaining p orbital function forms a weak π bond perpendicular to this plane. This weak bond gives semi-metal properties and very high electrical conductivity due to the superposition of the orbital function between adjacent atoms on the plane.

The conductive liquid combines these carbon nanotubes in a plurality of layers, is added to a solvent, and the liquid graphite solution is mixed and stirred. In order to ensure the stability of the stirred carbon nanotube solution, the polymer solution is mixed and wound using a surfactant. The prepared solution is filled in the cable 10 to be described later, and both ends of the cable 10 are completely sealed with electrode portions.

Carbon nanotubes include single-walled carbon nanotubes (SWNTs), double-walled carbon nanotubes (DWNTs), thin multi-walled carbon nanotubes, and multi-walled carbon nanotubes. One or a mixture of two or more selected from the group consisting of multi-walled carbon nanotubes (MWNTs) may be used. The carbon nanotubes may be pulverized by physically impacting the carbon nanotubes, and the carbon nanotubes may be crushed using a ball mill.

The endothelial 103 is formed in a cylindrical shape having a circular hollow portion therein and insulating so that the conductive solution 101 can be injected and received. Endothelial 103 may be formed of epoxy.

The inner circumferential surface of both ends of the inner shell 103 is formed with a screw groove formed with a female thread on the inner circumferential surface so as to screw the electrode portion described later.

The outer shell 104 is formed in a cylindrical shape to surround the outer side of the endothelial, and may be formed of PVC.

On the other hand, the cable according to the present invention may be further provided with a tube-shaped tube body 102 inside the endothelium 103 as shown. The tube body 102 is preferably formed of a material having a low thermal conductivity and high electrical conductivity so as to effectively block external heat from being transferred to the conductive liquid 101.

The electrode parts 20 and 30 are respectively coupled to both ends of the cable 10 to prevent the conductive solution 101 from leaking out of the cable 10 to seal the hollow portion of the cable 10, and the conductive solution 101. It is electrically conductive so as to be in contact with the conductive liquid 101.

The electrode portions 20 and 30 are provided with a connecting electrode portion 20 for connecting the cables 10 to each other, and an end portion of the cable 10 positioned on the end side of the cable 10 and a sealing panel, a distribution panel, a distribution panel, a distribution panel, and the like. And an end electrode portion 30 for connecting to the connected connection electrode.

The connecting electrode portion 20 is coupled to a screw groove provided at both end portions of the end shell end 103 of the cable 10 on one end and an end shell of the end cable 10 of the other cable 10, respectively. Are connected to each other, a cylindrical connecting electrode body 21 inserted into the endothelium and having an outer circumferential surface in close contact with the inner circumferential surface of the endothelium to seal the endothelium, and a connecting electrode body opposed to each other so as to be screwed into the screw groove of the endothelium. And a first connection screw coupling portion 22 and a second connection screw coupling portion 23 each of which extends a predetermined length from one side and the other side of 21 and each has a thread on its outer circumferential surface.

The end electrode portion 30 has an outer circumferential surface in close contact with the inner circumferential surface of the endothelial body, so that the end electrode body 31 can be screwed into a cylindrical end electrode body 31 for sealing the endothelium and a screw groove formed in the end-side endothelial of the cable 10. End screw coupling portion 32 and a screw thread formed on the outer circumferential surface extending a predetermined length from one side of the 31 and the end screw coupling portion 32 is in close contact with the end side of the cable 10 when screwed to the cable 10 Extending from one side of the flange portion 33 and the flange portion 33 opposed to the end screw coupling portion 32 so as to extend beyond the diameter of the end screw coupling portion 32 so as to be connected to a connection panel, a distribution board, and a distribution board. The terminal part 34 formed so that it may be connected to the connection electrode provided in the back etc. is comprised.

Power transfer using the conductivity of metal conductors is a traditional energy transfer medium that has been used for a long time and its physical properties are already known. In the power transmission method using metal conductors, the electrical properties of the metal, that is, the width between the valence band and the forbidden band are narrow and the electrons can be easily excited by the conduction band, and the conduction band is large so that many free electrons easily share each other's bands during metal bonding. As a result, the conductivity is good and the conductivity is high.

However, this easy electron movement causes the electrical equilibrium to break when extra electrons enter the equilibrium state of ions, and the ions of the same sign are rejected to each other, which eventually pushes them to the furthest distance from the conductor, causing extra charge to collect on the epidermis. Therefore, when the current flows in the actual conductor, electrons are concentrated on the surface and a skin effect is generated in which the current does not flow in the center of the conductor. As electrons concentrate on the epidermis, surface potential increases and excessive concentration of charge causes heat generation and dielectric breakdown.

However, the electric power cable structure using the conductive liquid medium according to the present invention utilizes the electrical properties of the ions present in the solution, and is divided into the conductive medium portion and the electrode portion for accommodating the solution, and the conductive liquid is disposed between the electrode and the electrode as a whole. The physics works like a capacitor and the electrical energy transfer transfers power by the alignment of ions by an electric field.

Although the density of free electrons is smaller than that of metals, ionized electrons do not have a high share of conduction bands between materials, making it difficult to be concentrated only on the surface, and the current density is evenly distributed at each point compared to metal conductors.

FIG. Is a conceptual diagram of a capacitor having a conductive solution as a medium.

At this time, the capacitance C is determined by the gap between the poles and the area of the electrode.

If the gap between the electrodes is d, the area of the electrode is S, and the permittivity of the conductive solution is ε, the capacitance is determined by Equation 1 below.

In addition, the electric charges charged between the poles are as shown in Equation 2, and the current flowing through these poles is as shown in Equation 3.

That is, the current flowing between the poles in the alternating voltage is such that the current flows by the capacitance C multiplied by the amount of change in voltage over time.

On the other hand, a represents an electrode at both ends of the cable to the circuit diagram of the conductive solution within the power cable with said V ₀ inductance that appears depending on the current flow is represented by L ₁ L ₂ L ₃ L _4, and the conductive medium, as shown in FIG. Excitation capacities can be represented by C ₁ C ₂ C ₃ .

If switch S is closed at this time, C ₁ , C2, charging the order of C ₃ is started and the final transmission power to a load connected to. The transmission rate to be transmitted depends on the magnitude of the L and C values. In general, the energy transfer rate is known as Equation 4.

Here, since the medium is a conductive solution rather than a metal, the transfer rate will depend almost on the capacitive C of the medium. If capacitive C has already been charged by default, it immediately begins to transfer energy to the load as soon as the switch is activated.

If an electric field is applied as an initial charged state and a current starts to flow, a magnetic field is formed by this current, and an electric field is generated by this magnetic field.

Create a transmission line circuit using a conductive solution as a medium and formulate the energy propagation equations in the transmission line. The transmission line by the conductive solution can be treated as a unique form of the transmission line because the characteristics of the transmission line depends on the C value.

A simplified diagram of a transmission line is shown in FIG.

Referring to FIG. 5, Kirchhof's law is applied to a closed loop constituting the entire circuit, as shown in Equations 5 and 6 below.

That is, since the change amount of the current is the change amount of the current according to the change in position, Equations 7 and 8 can be given.

Substituting Equations 7 and 8 into Equation 6 results in Equation 9 below.

이라고 하면, 수학식 10과 같다.Here, it is assumed that the element values of the transmission line are fixed values.

In this case, it is as shown in equation (10).

In other words, the amount of change in voltage at each position in the transmission line is the sum of the voltage drop in the inductance component plus the voltage drop in the resistance of the transmission line. Therefore, since the voltage drop according to the distance is determined according to the conductivity of the conductive solution, it can be seen that the conductivity of the conductive solution is a very important factor as a transmission line.

On the other hand, with reference to the circuit diagram shown in the drawings, when applying the current law of Kirchhof, the current at the parallel branch point is expressed by Equation 11.

Substituting Equations 7 and 8 into Equation 11 results in Equation 12.

This is summarized as in Equation 13.

이라고 가정하면 수학식 14와 같다.Where each electrical element is reported as a fixed element

Assume that Equation 14 is obtained.

That is, the rate of change of the current at each position is the sum of the rate of change of the current flowing in the shunt reactor and the current of the capacitor. In the equations derived above, the term causing loss in the circuit is due to the resistance R component and the shunt conductance G.

Now, if Equation 10 is further differentiated with respect to the distance, it is expressed as Equation 15 below.

Substituting this in Equation 14 above gives Equation 16.

Referring to Equation 14, the equation is the same as Equation 17 below, and this becomes a general wave equation.

If we assume that the conductivity of the medium Therefore, Equation 17 may result in a general wave equation of a lossless transmission path as shown in Equation 18 below.

The solution of the wave equation derived above is generally expressed in the form of equation (19).

는 Z축의 +방향으로 전파되는 전송파이고

는 -Z축 방향으로 전파되는 전송파이다. 일반적으로 전송선로에서 전파되는 파는 아래의 수학식 20과 같은 사인파형 전압이다.here

Is the transmission wave propagating in the + direction of the Z axis.

Is a transmission wave propagated in the -Z axis direction. In general, the wave propagating in the transmission line is a sinusoidal voltage as shown in Equation 20 below.

When the time t of Equation 20 is expressed as a term of the transmitted wave speed, it can be represented by Equation 21, and when Equation 20 is substituted into Equation 19, it can be expressed as Equation 22 below.

At this time, considering only the transmission wave propagated in the positive Z-axis direction and applying the Euler formula is shown in Equation 23 below.

At this time, it is called a phase equation that considers only the terms of space except the term of time, and is represented by Equation 24 below.

Now converting Equation 17 into a Phase equation is shown in Equation 25 below.

And factoring the equation (25) is equal to the equation (26).

(전파상수)를 수학식 27과 같이 두면, 수학식 28이 된다.here

If (wave constant) is given as in Equation 27, Equation 28 is obtained.

Now, if the wave equation is simplified as in Equation 29 below, the solution becomes Equation 30, and similarly, the phase with respect to the current is as Equation 31.

Derivation of the power transfer and loss characteristic equations is given by Equation 30, which is a variable value for the time t and the position Z. Same as 32 and 33.

At this time, since one period integral value of the cosine function is 0, the integral term for time is zero. Therefore, the result as shown in Equation 34 below can be obtained. In other words, as the distance increases, the transmission power also decreases.

On the other hand, according to the experiment, the power cable structure using the conductive liquid medium according to the present invention, when a commercial frequency AC voltage is applied to both ends of the electrode of the conductive solution, the CNTs in the solution start to entangle with each other by alternating the interfacial voltage and have a strong adhesion. Mechanical linkage begins. When the voltage rises, it forms a three-dimensional tube form as the current flows, and most of the current passes through this tube stage. The current flow is the sum of the displacement current and the conduction current, and the total current is expressed by Equation 35 below.

This displacement current is a function of capacitance and frequency of the conductive solution, and the displacement current is expressed by Equation 36.

In addition, the electrical characteristics of the cable by the conductive solution has a frequency dependent impedance in which the characteristics of the line constant depend on the characteristics of the capacitance of the cable.

The power cable structure according to the present invention described above has been described with reference to the accompanying drawings, which are merely exemplary, and those skilled in the art may various modifications and other equivalent embodiments therefrom. Will understand.

Therefore, the true technical protection scope of the present invention should be defined only by the technical spirit of the appended claims.

1: power cable structure
10: cable
20: connecting electrode
21: main body
22: first connection screw coupling portion
30: terminal electrode portion
31: main body
32: terminal screw coupling portion
33: flange
101: conductive solution
102: tube body
103: endothelial
104: sheath

Claims (3)

A cable including a conductive liquid conductive material capable of transferring electric power, an inner shell having a hollow portion formed therein and having insulation, and an outer shell formed to surround the outer surface of the inner shell so that the conductive liquid can be injected and received. and;
And an electrode unit coupled to both ends of the cable to prevent leakage of the conductive solution to the outside, and sealing the hollow part of the cable, and having an electrical conductivity to be in contact with the conductive solution to transfer power to the conductive solution. A power cable structure comprising a conductive liquid as a medium.
The method of claim 1,
Screw grooves are formed on the inner peripheral surfaces of both end portions of the endothelium,
The electrode portion is connected to the end of one end of the endothelial end and the end of the end of the end of the cable is connected to each other end of the end of the cable is connected to each other end of the end end of one end of the end end cable
The connection electrode part includes a cylindrical first connection electrode body and a first connection extending from one side and the other side of the connection electrode body opposite to each other so as to be screwed into the screw groove of the inner shell, and having a thread formed on an outer circumferential surface thereof. A screw coupling part and a second connecting screw coupling part;
The end electrode portion includes a cylindrical end electrode body and an end screw coupling portion extending from a side of the end electrode body by a predetermined length and having a screw thread formed on an outer circumferential surface thereof so as to be screwed into the screw groove of the endothelial. Power cable structure with liquid medium.
The method of claim 1,
The conductive solution is a power cable structure having a conductive liquid as a medium, characterized in that containing a carbon nanotube, graphite, surfactant.

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