KR20070111430A - Regulation apparatus of three phase distribution line for removing the harmonics - Google Patents

Abstract

A 3-phase voltage supply device is provided to improve a power factor by cancelling a phase deviation of an image harmonic current. A 3-phase voltage supply device supplies power to a load and includes first to third input terminals(10,20,30), first to third output terminals(r,s,t), and first to third cores(110,120,130). The input terminal receives power from the outside. The output terminals supply the power to the load. The cores are arranged to correspond to the respective output terminals and includes respective current coils. A first current coil is wired from the first input terminal to the second input terminal, and returns to the first input terminal. A second current coil is wired from the second input terminal to the third input terminal, and returns to the second input terminal. A third current coil is wired from the third input terminal to the second input terminal, and returns to the third input terminal.

Description

Harmonic elimination three-phase constant voltage device {Regulation apparatus of three phase distribution line for removing the harmonics}

The present invention relates to a three-phase constant voltage device capable of removing harmonics, and in particular, by connecting each phase to each other in parallel to the three-phase reactor, the phase shift difference can be made within a predetermined range, thereby eliminating harmonics that can remove image harmonics. It relates to a possible three-phase constant voltage device.

In general, a transformer is an inductive coupling of two electrical circuits by two or more windings or by a single winding with a tab, with and without windings.

As used in such a transformer, reactive power refers to power that does not actually do anything and consumes no heat since the inflow and reception of energy from a power source is repeated every half cycle when an alternating current flows through an inductor and a capacitor. It refers to power that doesn't actually work. If the effective values of AC voltage and current are V and I, respectively, and the phase angle is θ, the apparent power becomes VI, and the active power and reactive power are represented by VIcosψ and VIsinψ respectively.

In addition, the effective power is a quantity given by VIcosθ when the effective value of voltage is V, the effective value of current is I, and the phase difference between them is θ. This is the power that changes from the load to the actual effective one, as opposed to reactive power or apparent power.

Power factor refers to the effective power divided by the apparent power, and the circuit resistance divided by the circuit impedance at the operating frequency. If the circuit currents are all sine waves, the power factor is the cosine of the phase difference between voltage and current.

The supply voltage from the utility company varies somewhat depending on the location of the transformer and the length of the wiring, and the voltage drop rate may also vary from customer to customer. That is, power is supplied from the distribution transformer of one bank to each customer, and the supply voltage is set such that the voltage at the end of the distribution transformer tap is maintained at 220V. However, the customer near the power distribution transformer receives a supply voltage higher than 200V, causing overheating and malfunction of the electric equipment, blackening of the lighting equipment, etc., resulting in excessive power consumption and shortening the life of the electric equipment.

Accordingly, in the case of electric equipment using a rated voltage of 220V or 380V, there should be no abnormality in use within the voltage range of 198 to 242V and ± 342% and 342 to 418V, which are ± 10%. By using the allowable voltage characteristic that should be no problem for the normal operation of the equipment within the specified range, the power supply is reduced to the minimum rated voltage of the load to reduce the power consumption, thereby saving power.

An example of a technique for obtaining a power saving effect as described above is disclosed in Korean Utility Model Publication No. 20-343827.

1 is a connection diagram of a three-phase four-wire power saving transformer disclosed in the above publication.

The transformer for a power saver illustrated in FIG. 1 includes a neutral wire 40 and 300 having an input terminal N and an output terminal n. The current coil includes R phase, S phase and T phase current coils 302, 304 and 306. The R phase current coil 302 includes an output side r connected in series with the input side R and the input side R and having the same potential as the input side R. The S phase current coil 304 includes an output side s connected in series with the input side S and the input side S and having the same potential as the input side S. The T-phase current coil 306 includes an output side t connected in series with the input side T and the input side T and having the same potential as the input side T.

The voltage coil includes R phase, S phase and T phase voltage coils 308, 310 and 312. The R phase voltage coil 308 includes primary and secondary side lines L1 and L1, and the S phase voltage coil 310 includes primary and secondary side lines L2 and L2, and the T phase voltage coil. 312 is the primary side and secondary side

Lines L3 and L3. The primary and secondary lines L1 and L1 of the R-phase voltage coil 308 are connected to the input side R and the N-phase output side n of the R-phase current coil 302, respectively, and the S-phase voltage coil 310 The primary side and secondary side lines L2 and L2 of) are connected to the input side S and the N phase output side n of the S phase current coil 304, respectively, and the primary side and 2 of the T phase voltage coil 312. The difference side lines L3 and L3 are connected to the input side T and the N phase output side n of the T-phase current coil 306, respectively.

The secondary lines L1, L2, and L3 are commonly connected to the input terminal N or the output terminal n of the midline 300 so that the voltage coils 308, 310, 312 are Y-connected. The midline provides a transformer for the energy-saving unit that can be connected to the input and output side jointly to use a three-phase 380V power supply and a single-phase 220V power supply.

However, in the technique disclosed in the above publication, the power consumption can be reduced by reducing the constant voltage to supply the electric power such as a motor by reducing the fluctuation range of the input voltage to reduce the power consumption, but the imbalance between the three phases is not considered at all. It is not.

That is, in the distribution transformer, the three-phase output terminal is connected to the three-phase input terminal through the distribution line, each winding is connected to the neutral point, and the harmonic current flows to the neutral wire because the output terminal is connected to the load motor or various electronic devices. As the harmonic currents are synthesized with the scalar values of each phase, the current flowing through the neutral wires causes an overcurrent to flow, resulting in the loss of the neutral wires and the occurrence of fire due to the overheating, and the loss of power.

The present invention has been made to solve the above problems, an object of the present invention is to connect the wiring method of each phase in a three-phase transformer device, and to reduce the image harmonic current flowing by combining the scalar amount in the neutral line in each phase It is an object of the present invention to provide a three-phase constant voltage device capable of removing image harmonics capable of removing harmonic components by constituting a reactor that is one thousandth less than the impedance of a power transformer.

The present invention includes the following examples in order to achieve the above object.

In the first embodiment of the present invention, in a three-phase constant voltage device for supplying power to a load, the R, S, T terminals supplied with external power and the r, s, t output terminals for supplying voltage to the load ; It is provided corresponding to the R, S, and T terminals, and includes first to third cores each of which is wound around the current coil, the current coil is passed through the R terminal to the S terminal again, R terminal, S terminal in the T terminal It is characterized by being alternately connected for each terminal as a T terminal through the S terminal, T terminal through the terminal.

According to a second embodiment of the present invention, in the first embodiment, the current coil includes first to third current coils wound on the first core and fourth to sixth current coils wound on the second core. And seventh to ninth current coils wound on the third core, wherein the first current coil, the fifth current coil, and the third current coil are connected in series with the R terminal, and the fourth current coil. An eighth current coil and a sixth current coil are connected in series with the S terminal, and the seventh current coil, the second current coil, and the ninth current coil are connected in series with the T terminal.

The third embodiment of the present invention, in the second embodiment, the first, fifth, third current coil connected to the R terminal, and the fourth, eighth, sixth current coil connected to the S terminal And the number of turns of the seventh, second, and ninth current coils connected to the T terminal is 2, 4, and 2 turns.

In a fourth embodiment of the present invention, in the third embodiment, the first, third, fourth, sixth, seventh, and ninth current coils are wound in the same direction.

According to a fifth embodiment of the present invention, in the fourth embodiment, the second current coil, the fifth current coil, and the eighth current coil are wound in opposite directions to the other current coils.

In the sixth embodiment of the present invention, in any one of the first to fifth embodiments, the harmonic-removable three-phase constant voltage device is

A first voltage coil whose one end is connected in parallel with the first current coil and whose other end is connected to the neutral wire, a second voltage coil whose one end is connected in parallel with the fourth current coil and the other end connected to the neutral wire, and one end of the first voltage coil It is characterized in that it further comprises a third voltage coil connected in parallel with the seven current coil and the other end is connected to the neutral line.

As described above, the harmonic-removable three-phase constant voltage device according to the present invention has an effect of reducing the loss due to the image harmonic current and improving the power factor by causing the phase shift of the image harmonic current to cancel.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated according to drawing.

2 is a schematic diagram showing the connection of a harmonic-removable three-phase constant voltage device according to the present invention.

2, the present invention is an output terminal for supplying a constant voltage to the load, such as R, S, T terminals (10, 20, 30) and the neutral terminal (N) and the motor, which is a three-phase input terminal supplied from a power source (r, s, t).

Further, the first, fifth and third current coils 11, 22 and 13 on R leading from the R terminal 10 to the output terminal r and the S terminal 20 to the output terminal s. Fourth, eighth, and sixth current coils 21, 32, and 23 on S phase, and the seventh, second, and ninth current coils 31, on T, which extend from the T terminal 30 to the output terminal t. 12 and 33 respectively include current coils connected in series and voltage coils in which the first to third voltage coils 51, 52, and 53 are connected between the respective phases R, S, and T, and the neutral line N. FIG. do.

Here, the first to ninth current coils 11 to 13, 21 to 23, 31 to 33, and the first to third voltage coils 51, 52, and 53 are respectively formed on the first core 110 of the R terminal 10. ), The second core 120 of the S terminal 20, and the third core 130 of the T terminal 30 are wound, respectively, the first voltage coil 51 is the first core 110, second The voltage coil 52 is wound around the second core 120 and the third voltage coil 53 around the third core 130, respectively. In addition, the first to third cores 110, 120, and 130 are made of iron or silicon steel as a conventional shell type core. That is, the material of the core is preferably iron or silicon steel sheet depending on the use of the load.

The first current coil 11 of the R phase is connected to the fifth current coil 22 of the S phase, and the fifth current coil 22 of the S phase is connected in series to the third current coil 13 of the R phase.

In addition, the fourth current coil 21 of the S phase is connected to the eighth current coil 32 of the T phase, and the eighth current coil 32 of the T phase is serially connected to the sixth current coil 23 of the S phase. Leads to.

The seventh current coil 31 of the T phase is connected to the second current coil 12 of the R phase, and the second current coil 12 of the R phase is connected in series to the ninth current coil 33 of the T phase. .

In addition, the third current coil 13 is connected to the output terminal r of the R phase, the sixth current coil 23 is connected to the output terminal (s) of the S phase, the ninth current coil 33 Is connected to the output terminal (t) of T phase.

Here, the first to third current coils 13 of the first core 110 are wound as turns of 2, 4, and 2, respectively, and the fourth to sixth current coils 23 of the second core 120 are wound. And the seventh through ninth current coils 31, 32, and 33 of the third core 130 are also wound as turns of 2, 4, and 2, respectively.

In addition, the first and third current coils 11 and 13 are wound in a direction opposite to the second current coil 12, and the fourth and sixth current coils 21 and 23 may be fifth current coils. 22), the seventh and ninth current coils 31 and 33 are wound in the opposite direction to the eighth current coil 32.

In addition, an input side and an output side of the first voltage coil 51 are connected to the R terminal 10 and the neutral lines N and n, respectively, and an input side and an output side of the second voltage coil 52 are the S terminal. 20 and the neutral wires N and n, respectively, and the input side and the output side of the third voltage coil 53 are connected to the T terminal 30 and the neutral wires N and n, respectively.

The configuration in which the first to third cores 110, 120, and 130 are connected as described above is the same as that of the equivalent circuit of FIG. 3. 3 is an equivalent circuit diagram of a harmonic-removable three-phase constant voltage device according to the present invention.

Referring to FIG. 3, in the R terminal 10, a first current coil 11, a fifth current coil 22, and a third current coil 13 are connected in series, and the first voltage coil 51 is connected to the R terminal 10. The first current coil 11 is connected to the neutral lines (N, n) in the same direction as the magnetic field generated.

In addition, the S terminal 20 is connected to the fourth current coil 21, the eighth current coil 32 and the sixth current coil 23 in series, the second voltage coil 52 is the second The four current coils 21 are connected to the neutral lines N and n in the same direction as the magnetic field generated.

In addition, the T terminal 30 is connected to the seventh current coil 31, the second current coil 12 and the ninth current coil 33 in series, the third voltage coil 53 is the seventh The current coil 31 is connected to the neutral lines (N, n) to be in the same direction as the magnetic field generated.

The current input from the R terminal 10 is output to the output terminal r through the first current coil 11, the fifth current coil 22, and the third current coil 13. As described above, the number of turns of the first current coil 11, the fifth current coil 22, and the third current coil 13 is wound by turns of 2, 4, and 2, respectively, and the fifth current coil 22 is wound. ) Winding direction is wound at 120 turns in the opposite direction to the first and third current coils (11, 13).

In addition, the current input from the S terminal 20 is output to the output terminal s through the fourth current coil 21, the eighth current coil 32, and the third current coil 23, wherein As described above, the number of turns of the fourth current coil 21, the eighth current coil 32, and the sixth current coil 23 is wound by turns of 2, 4, and 2, respectively, and the eighth current coil 32 ) Winding direction is wound at 120 turns in the opposite direction to the fourth and sixth current coils 21 and 23.

In addition, the current input from the T terminal 30 is output to the output terminal t via the seventh current coil 31, the second current coil 12, and the third current coil 33. As described above, the number of turns of the seventh current coil 31, the second current coil 12, and the ninth current coil 33 is wound by turns of 2, 4, and 2, respectively, and the second current coil ( The winding direction of 12 is wound at 120 turns in the opposite direction to the seventh and ninth current coils 31 and 33.

In addition, the first to third voltage coils 51, 52, and 53 have the current coils 11 to 13, 21 to 23, and 31 to 33, respectively. Reverse phase voltage is induced and developed by electromagnetic induction according to the phase difference between S, T) and neutral wire (N, n) to provide voltage drop for the load. It induces electron induction to give current feedback effect.

As described above, in the present invention, the second current coil 12, the fifth current coil 22, and the eighth current coil 32 are opposite to other current coils in the first to third cores 110, 120, and 130. Direction and the first and third current coils 11 and 13 are alternately connected with the fifth current coil 22 wound in the other direction, so that image harmonics generated in each phase exhibit a phase shift of about 22 °. Each harmonic current generated in each phase is canceled in the neutral line.

In addition, in the present invention, the current coil is induced with the reverse phase voltage with respect to the voltage coil by the electromagnetic induction of the voltage coils connected in parallel to provide a voltage drop to the load, and the series-coiled current coils induce the electrons in the voltage coil by the load current amount. The power feedback action reduces the input current. In addition, the two windings at the bottom shown in FIG. 3 are wound in opposite directions to offset the phase of the harmonic image current, thereby improving the power factor and reducing the power loss caused by the image harmonic current.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

The harmonic-removable three-phase constant voltage device according to the present invention can be usefully used in a distribution line including an image harmonic current.

1 is a circuit diagram showing a conventional three-phase four-wire constant voltage transformer,

Figure 2 is a schematic diagram showing the connection of the harmonic removable three-phase constant voltage device according to the present invention,

3 is an equivalent circuit diagram of a harmonic-removable three-phase constant voltage device according to the present invention.

* Description of the symbols showing the main parts of the drawings *

10: R terminal 11: First current coil

12: second current coil 13: third current coil

20: S terminal 21: Fourth current coil

22: fifth current coil 23: sixth current coil

30: T terminal 31: 7th current coil

32: 8th current coil 33: 9th current coil

40: neutral wire 110: the first core

120: second core 130: third core

r, s, t, n: Output stage

Claims (6)

In the three-phase constant voltage device for supplying power to the load, An R, S and T terminal receiving external power and an r, s and t output terminal for supplying a voltage to the load; Including the first to third cores provided corresponding to the R, S, T terminals, each of which includes a wound current coil, The current coil is connected to the R terminal, S terminal again, R terminal, S terminal, T terminal, S terminal, T terminal, S terminal, T terminal as a cross terminal for each harmonic elimination, characterized in that Constant voltage device. The method of claim 1, The current coil is First to third current coils wound around the first core, Fourth to sixth current coils wound around the second core; Including the seventh to ninth current coil wound on the third core, The first current coil, the fifth current coil and the third current coil are connected in series with the R terminal, The fourth current coil, the eighth current coil, and the sixth current coil are connected in series to the S terminal. And the seventh current coil, the second current coil, and the ninth current coil are connected in series to the T terminal. The method of claim 2, First, fifth and third current coils connected to the R terminal; Fourth, eighth and sixth current coils connected to the S terminal; And the number of turns of the seventh, second, and ninth current coils connected to the T terminal is 2, 4, and 2 turns, respectively. The method of claim 3, And the first, third, fourth, sixth, seventh, and ninth current coils are wound in the same direction. The method of claim 4, wherein And the second current coil, the fifth current coil, and the eighth current coil are wound in opposite directions to other current coils. The method according to any one of claims 1 to 5, The harmonic removable three-phase constant voltage device A first voltage coil having one end connected in parallel with the first current coil and the other end connected with a neutral wire; A second voltage coil having one end connected in parallel with the fourth current coil and the other end connected with the neutral wire; And a third voltage coil having one end connected in parallel with the seventh current coil and the other end connected with the neutral line.

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