KR100940294B1 - Arrangement strucyure of burs bars used in 3-phase power for decreasing impedance - Google Patents

Abstract

The present invention relates to an array structure of plate conductors in which three-phase alternating current flows, and more particularly, by arranging the plate conductors to have three-phase symmetry, magnetic fields generated in each plate conductor are canceled by interaction and associated with reactance ( By reducing XL) and increasing the penetration depth of electrons, the increase resistance (R) that is increased in the AC circuit is reduced. In this connection, the composite impedance of the plate conductor section is reduced, thereby reducing the power loss in the conductor. It is about.

The arrangement of the three-phase AC power plate conductors of the present invention is a three-plate conductor (Bus bar) for transmitting three-phase AC power, characterized in that the three plate conductors are arranged symmetrically to each other.

Description

Arrangement structure of burs bars used in 3-phase power for decreasing impedance

The present invention relates to an array structure of plate conductors in which three-phase alternating current flows, and more particularly, a magnetic field generated in each plate conductor by arranging the plate conductors in three-phase symmetry (ie, facing each other in a balanced manner). This interaction is offset and the associated reactance (XL) is reduced and the increase in electron penetration depth reduces the increase in resistance (R) that is increased in the AC circuit, thereby reducing the composite impedance of the plate conductor section in connection with the conductor. The present invention relates to an arrangement of plate conductors with reduced power loss.

As is well known, copper (cu) and aluminum (AL) with low power loss are mainly used as a conductor for transmitting power. In addition, the conductor for transmitting power mainly uses a cable having a circular cross section, but in a power distribution facility, a plate-like conductor is used as a conductor for power transmission. The plate conductor is called a bus bar.

The use of plate-shaped conductors in water distribution facilities is to reduce power loss and increase economic efficiency due to the skin effect of the conductors. In other words, the skin effect means that when a current flows in a conductor (that is, when there is a movement of electrons in the conductor), the current flows distributed on the surface of the conductor and hardly flows inside the conductor. The inner side in X makes little contribution to power transmission. Therefore, the plate-like conductor which can minimize the inner part and improve the power transmission efficiency according to the skin effect is mainly used in the water distribution facility.

And since the power distribution equipment supplies three-phase AC power to the load side, three or four plate conductors are provided, and the arrangement structure of the plate conductors according to the prior art is arranged side by side or upright as shown in FIGS. .

In the plate conductor flowing three-phase AC power, the impedance of the plate conductor increases due to the change in polarity of the current and the mutual influence between the plate conductors, and the loss of power transmitted by the increased impedance occurs.

       In addition, the three-phase magnetic field canceling conditions are asymmetrical, so the three-phase impedance of the three-plate conductor occurs differently in the same section. Therefore, an unbalance of the three-phase voltage supplied to the load side is caused, and power loss is caused by the unbalance of the voltage.

Therefore, it is necessary to minimize the power loss in the plate conductor during power transmission by suppressing the impedance increase of the plate conductor when three-phase AC power flows.

The present invention has been made in accordance with the above needs, arranged to face the three plate conductors to which the three-phase AC power is transmitted at an acute angle to each other, to reduce the power loss by reducing the impedance of the plate conductors during power transmission 3 An object of the present invention is to provide an arrangement of plate conductors for phase AC power.

The arrangement structure of the three-phase AC power plate conductors of the present invention for achieving the above object is

In three-bar conductors that transmit three-phase AC power,

The three plate-like conductors are arranged to face each other at an acute angle.

And the three plate-shaped conductor is characterized in that arranged in a triangle or Y shape,

The plate conductor has a bent portion at the center in the longitudinal direction, and is characterized in that the three plate conductors are arranged in a Y shape.

The arrangement of the three-phase AC power plate conductor according to the present invention is compared with the arrangement of the plate conductor according to the prior art, as shown in the test comparison table of FIG. 3C, the resistance R is reduced by about 8%, and the reactance ( X) is reduced by about 38% and impedance (Z) is reduced by about 36%.

The reduction of the conductor impedance at such a value is very large, and the present invention is a very useful invention for industrial development that can greatly contribute to the prevention of power loss in the conductor during power transmission.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

2, a, b, and c show an example of an arrangement structure of the plate conductors according to the present invention, in which three plate conductors are arranged to face each other in balance. That is, the three plate conductors face each other at an acute angle.

First, in FIG. 2A, the three plate-shaped conductors R1, S1, and T1 are fixedly coupled to the support member 11 by bolts, and arranged in a triangular shape facing each other at an angle of about 60 degrees.

In FIG. 2B, the three plate-shaped conductors R2, S2, and T2 are fixedly coupled to another support member 12 by bolts, and are arranged in a Y shape with an angle of about 120 degrees to each other.

In Fig. 2c, the plate-shaped conductors R3, S3, and T3 have a bent portion bent at about 120 degrees in the center of the longitudinal direction, and the three plate-shaped conductors R3, S3, and T3 are fixedly coupled to another support member 13 by bolts. Er are arranged in a Y-shape.

The plate-like conductors of FIG. 2C are Y-shaped as a whole, but the plate-shaped conductors face each other in parallel with each other, that is, at an angle of 180 degrees. It can be said that the balance up to 180 degrees, so that the three plate conductors in the balanced and facing category also includes Figure 2c.

Three-phase conductors flow three-phase alternating currents having a phase difference of 120 degrees, and a three-phase power source having a phase difference is generally represented by R phase, S phase, and T phase for each phase. Therefore, in the drawings, three plate conductors were numbered with R, S, and T numbers.

Figure 3a is a test result table in a structure in which the three plate-like conductors (r2, s2, t2) erected vertically in accordance with the prior art as shown in Figure 1b is arranged, Figure 3b is the present invention as shown in Figure 2b Is a test result table in a structure in which the three plate-shaped conductors R2, S2, and T2 are arranged in a Y shape, and FIG. 3C is a result table comparing the test results of FIGS. 3A and 3B.

Each plate conductor used in the test is copper, 8mm thick, 40mm wide, and 320mm ^ 2 in cross section.

And the current transformer (manufacturer; alarm electric) for measuring the current flowing through the plate conductor has a capacity of 600 / 5A, 15VA, and the current is about 2.5 degrees late, so it compensated 2.5 degrees when calculating the resistance, and the line voltage of the plate conductor. The oscilloscope was measured for the same section length of 2m, and the three plate conductors were calibrated within + -2 degrees based on 120 degrees, and the same section was measured twice under different conditions.

Here, the different test conditions are the phase of the three plate conductors (r2, s2, t2) in the test of Figure 3a, the current phase in the test 1 is within the line 120 degrees error range + -2 degrees in the test 2 and the voltage of the test The phase was within 120 degrees between the error range + -2 degrees. In the test of FIG. 3b, the phase of the three plate conductors (R2, S2, T2) was used, and in the test 1, the current phase was within 120 degrees between the error range + -2 degrees. In test 2, the phase of the voltage was within the range of 120 degrees between error + -2 degrees.

In the arrangement of the three-plate conductor according to the prior art as shown in Figure 3a,

The measured current propagation type (pkpk) value (measured on the secondary side of the current transformer) flowing through the three plate conductors in Test 1 and Test 2, respectively, was 12.8A and 12.83A in three phases, and the propagation type of the measurement voltage between the three plate conductors ( The pkpk) value (measured by the voltmeter measuring 2 m length) was three-phase average of 731 mV and 702 mV, and the average of phase difference between current and voltage of each of the three plate conductors was measured at 73.50 degrees and 72.97 degrees. The average exothermic temperature of the three plate conductors was 45.77 degrees and 45.57 degrees.

Based on this, the impedance values of the three plate conductors were calculated in Test 1 and Test 2, and the average resistance (R) and reactance (X) were 0.00015 (R), 0.000445 (X), 0.00015 (R), and 0.000426. (3), the total impedance of the three sections of all three plate conductors was calculated as Z = 0.00143, R = 0.000457, X = 0.00128, Z = 0.00137, R = 0.000454, X = 0.00128 in Test 1 and Test 2, respectively. The average of test 1 and test 2 was calculated as Z = 0.00140, R = 0.000455, X = 0.00128.

In the arrangement of the three plate conductors according to the present invention, as shown in FIG. 3B, the measured current propagation type (pkpk) value (the current value measured at the secondary side of the ammeter) flowing through the three plate conductors in Test 1 and Test 2, respectively, is Three-phase average is 12.83A and 12.73A, and the propagation type (pkpk) value (measured by a voltmeter measuring 2m length) of three-plate conductor line voltage is 460.7mV and 454.7mV in three-phase average, and the current of each of the three-plate conductors The average phase difference of eddy voltage was 64.69 degrees and 64.57 degrees. The average exothermic temperature of the three plate conductors was measured at 46.17 degrees and 45.80 degrees.

Based on this, the impedance values of the three plate conductors were calculated in Test 1 and Test 2, and the average resistance (R) and reactance (X) were 0.00014 (R), 0.000264 (X), 0.00014 (R), and 0.000263. (3), and the sum impedance of the three plate conductors was calculated as Z = 0.00090, R = 0.000419, X = 0.00079, Z = 0.00089, R = 0.0004419, X = 0.00079 in Test 1 and Test 2, respectively. The average of test 1 and test 2 was calculated as Z = 0.00090, R = 0.000419, X = 0.00079.

As shown in the comparison result table of FIG. 3C, the arrangement of the plate conductors according to the present invention has a total impedance (Z) of 64%, a resistance (R) of 92%, and a reactance of the plate structure of the prior art. (X) is only 62%. That is, in the present invention, the impedance is reduced by 36%, the resistance by 8%, and the reactance by 38%. As a result, the power loss to the plate conductor was also reduced.

As can be seen from the above test result table, even when using plate-like conductors having the same electrical properties, the three plate-like conductors (Fig. 1B r2, s2, t2) are arranged according to the prior art, and the plate-like conductors according to the present invention (Fig. 2B R2). In the arrangement of, S2, T2), the difference in the impedance of the plate conductors when the three-phase AC power flows is considered to be due to the difference in the interaction according to the arrangement of the plate conductors.

The impedance Z of a conductor through which AC power flows consists of a resistance R and a reactance X.

In the present invention, both reactance X and resistance R are reduced as compared with the prior art, and the principle is considered as follows.

The principle of reduction of reactance X.

Reactance X consists of capacitive reactance XC and inductive reactance XL.

The characteristic of the capacitive reactance Xc is that the current flows in phase 90 degrees before the voltage, and the characteristic of the inductive reactance XL flows in the phase 90 degrees behind the voltage.

In this connection, the reactances Xc and XL are 180 degrees out of phase, so the combined values are subtracted. (Formula X is XL-Xc and negative is Xc positive is XL)

Capacitive reactance XC occurs when current flows with two conductors facing each other with a dielectric (eg air) in between.

In the present invention, the three plate-shaped conductors R2, S2 and T2 of Fig. 2B are arranged to face at the same angle. Thus, the capacitive reactances XC generated between the plate conductors of R2 and S2, S2 and T2, and T2 and R2 in FIG. 2B have a similar size and are balanced.

In contrast, in the prior art, the plate-like conductors r2, s2, s2, and t2 of the three plate-shaped conductors r2, s2, and t2 of FIG. 1B face each other, but the plate-like conductors of r2 and t2 do not face each other. Thus, capacitive reactance Xc is generated in the plate conductors of r2 and s2, s2 and t2, but capacitive reactance Xc is not generated in the plate conductors of r2 and t2, or it is negligible even if it is generated.

Thus, the amount of capacitive reactance Xc generated between the three plate conductors r2, s2, t2 of FIG.

Inductive reactance XL generates a magnetic field that changes direction over time when an alternating current flows through the conductor, which affects the current flowing through the conductor and the voltage across the circuit, preventing the flow of current. = 2pfL)

In the present invention, the three plate conductors (R2, S2, T2) are arranged in three phase symmetry, almost every two plate conductors are the same in the current direction and the other plate conductor is different in the current direction. [1st law of Kirchhoff; The sum of the input and output currents of the network is zero. (Current (I) = 0)] Therefore, the magnitude of the magnetic field produced by the plate conductors with different current directions and the combined magnetic field of the two plate conductors with the same current direction are the same and the conductors are arranged in a symmetrical manner, so that they cancel each other out and disappear. do. Therefore, generation of inductive reactance XL is suppressed.

In contrast, in the related art, three plate conductors r2, s2, and t2 are arranged side by side, and the magnetic fields generated in the plate conductors of r2 and s2, s2 and t2 facing each other are either one (eg, plate plates of r2 and s2). The conductors meet and cancel each other and disappear, but the other side (between the plate conductors of s2 and t2) meets and amplifies. Therefore, the inductive reactance XL of each plate conductor is different in size.

As a result of the difference in the amount of magnetic fields canceled and dissipated from each other, the present invention is to reduce the inductive reactance XL compared with the prior art.

Reduction principle of resistance R.

The resistance R of the conductor is proportional to the resistivity of the conductor. Silver and copper are typical of low resistivity metals.

Other factors affecting the resistance R of the conductor include the skin temperature and the proximity effect, which affect the temperature of the conductor and the distribution of free electrons in the conductor when current flows in the conductor.

As described above, the skin effect is an effect of free electrons concentrating on the surface of the conductor, which generates a current when the current flows in the conductor,

Proximity effect refers to the effect of free electrons concentrating on the outside of two conductors when current flows in two adjacent conductors, when the two currents are in the same direction, and inside the conductors when the two currents are different. .

Due to the phase difference, three conductors in which three-phase alternating current flows are mostly two conductors in the same direction each time, and the other conductor has a different flow direction from the other two conductors.

Therefore, in the arrangement according to the prior art in which the three plate-like conductors are arranged side by side as shown in Figure 1b, r2 and s2, s2 and t2 has a proximity effect, but r2 and t2 do not have a proximity effect, In the plate conductors r2, s2 and t2, only when free electrons are concentrated on one side and the current flow of the plate conductor s2 arranged in the middle is different from the current flow direction of the plate conductors r2 and t2 arranged on both outer sides. Free electrons in the plate conductor s2 disposed in the middle are dispersed throughout the surface. Of course, also at this time, the free electrons of the two plate conductors (r2, t2) disposed on the outside are concentrated on one side.

However, in the arrangement according to the present invention in which the three plate-shaped conductors R2, S2, and T2 are arranged to face each other, as shown in FIG. 2B, the three plate-shaped conductors R2, S2, and T2 are close to each other. Therefore, two plate-like conductors (assuming S2 and T2) having the same flow direction of current are concentrated by free electrons being pushed outward by mutual proximity effect, but the plate-like conductor R2 having different flow direction of current has two plate-like conductors (S2, Proximity effect is generated in T2) and is pushed outward to attract the concentrated free electrons inward. Thus, in the two plate conductors S2 and T2, free electrons are evenly distributed throughout the surface.

In addition, as described above, the present invention is canceled by the three-phase interaction of the magnetic field to reduce the induced electromotive force compared with the prior art and in this regard is less affected by the skin effect and proximity effect, the efficiency of the conductor is increased.

As described above, when a three-phase alternating current flows, in the prior art, free electrons are concentrated to one side of the surface in each plate conductor, and in the present invention, the free electrons are dispersed in the entire surface in the two plate conductors. It is believed that the resistance R decreases.

The flow of current is generated by the movement of free electrons. The concentration of free electrons to one side means that the movement path of the free electrons is narrowed so that the movement of the free electrons is restricted and the resistance R increases.

In the present invention, since the impedance of the three plate conductors is similar to each other in three phases, voltage imbalance does not occur, but the prior art causes voltage imbalance because the impedances of the three plate conductors are different from each other.

In the above description of the present invention, the arrangement of three-phase AC power plate conductors for reducing impedance having a specific shape and structure has been described with reference to the accompanying drawings, but the present invention can be variously modified and changed by those skilled in the art. And, such variations and modifications should be construed as falling within the protection scope of the present invention.

Figure 1 a, b is a perspective view of the arrangement of the plate conductor for three-phase AC power according to the prior art.

Figure 2 a, b, c is a perspective view of the arrangement of the plate-like conductor for three-phase AC power in accordance with the present invention.

3, a, b, and c are test result tables in the arrangement according to the prior art, test result tables in the arrangement according to the present invention, and result tables comparing both test results.

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

r1, r2 / s1, s2 / t1, t2: plate conductor (prior art)

R1, R2, R3 / S1, S2, S3 / T1, T2, T2: plate conductor (invention technology)

11, 12, 13: support member

Claims (4)

In the three bar conductor (Bus bar) for transmitting three-phase AC power, The three plate conductors are arranged to face each other in a balanced manner, The plate conductor has a bent portion in the center in the longitudinal direction, the three plate conductors are arranged in a Y-shaped arrangement of three-phase AC power plate conductor for reducing the impedance. delete delete delete

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