KR101893766B1 - Variable reactor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable reactor, and more particularly, to a variable reactor that linearly varies a reactance value by varying a section where an iron core and a core overlap each other.

Description

Variable reactor {VARIABLE REACTOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable reactor, and more particularly, to a variable reactor that varies a reactance value by varying a section where an iron core and a core overlap each other.

Reactors are often coiled around an iron core, with no core. A shunt reactor that is installed in parallel with the power transmission system to supply the ground current and a current limiter that is used to limit the fault current in case of short - Reactors, and arc extinguishers that spontaneously destroy the ground arc when a line ground fault occurs in the transmission line. There is also a saturable reactor using the saturation phenomenon of a ferromagnetic iron core.

Such a reactor is mainly used for absorbing reactive power by a large inductive reactance in an AC circuit, but it is a device for giving reactance only to an AC component in a circuit in which AC and DC are overlapped. Structurally, there are air core type, closed core type, and pore type.

Generally, the long-distance transmission line generates the phase-ineffective current due to the charging current due to the long-distance transmission. The shunt reactor is installed in parallel with the line to appropriately adjust the balance of the reactive power.

Generally, by installing a shunt reactor with a constant capacity in the power supply line, the reactive current of the rated capacity is absorbed, thereby increasing or decreasing the reactive current. Especially, if the load is heavy or heavy, There is a possibility that the reactor is separated from the circuit to maximize the effect.

However, if the proper capacity is not selected, a large reactive current is consumed in the reactor, thereby increasing the line loss and further lowering the power factor.

In order to overcome this problem, there are various techniques which can change the capacity of the shunt reactor by providing a shunt reactor tap and controlling the electrical connection between the taps based on the reactive current to the power distribution line,

In the case of the reactor tap control method (NLTC) by no-load tap, the tap is switched in the state in which power is cut off to the reactor, that is, in the no-excitation state. do. There is a problem that a serious arc is generated between the tabs when the tabs are switched in a light load state in which the load is slightly burdened or in a light load state in which the power supply is not interrupted,

In the case of the reactor tap control method (OLTC) by the on-load tap, it is a compensation method that compensates the reactive current by automatically transferring the current to the tap in a state where the load is applied. Although continuous control is possible as a method of adjusting the reactive current by varying the tap in the excited state of the reactor, there is a problem that position control is performed using the three-phase induction motor.

In the case of the tap control system that combines multi-circuit switches during reactor tap change, adjustment of the reactive current by the shunt reactor is applied to the shunt reactor by applying the tap control principle of the transformer, and the reactor has a value of 100 [%] There is almost no change in the value of the reactor, but there is a problem that a very large arc is generated when the contactor moves between the tabs during tap switching of the shunt reactor.

Korean Registration Practice [20-0392618] discloses a saturable reactor type power saving device using a tap switching method.

Korean Registration Practice [20-0392618] (Registered on August 03, 2005)

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a variable reactor that linearly varies a reactance value by varying a section where an iron core and a core overlap each other.

The objects of the embodiments of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description .

According to an aspect of the present invention, there is provided a variable reactor, the variable reactor having a predetermined shape, the variable reactor having a predetermined shape, the reactance being induced in response to a change in alternating current or current by accumulation of electromagnetic energy, (100); A core part (200) in which a moving space of the iron core part (100) is formed on a center line and in which a coil is wound; And a driving unit 300 for moving the core unit 100 or the core unit 200 to vary the interval between the core unit 100 and the core unit 200.

The iron core 100 is formed in a columnar shape.

The iron core 100 is characterized by being formed into a bar shape having an arc-shaped center line.

In addition, the iron core 100 is formed in a bar shape having a spiral center line.

In addition, the driving unit 300 may vary a section in which the core unit 200 and the core unit 100 are overlapped by driving the motor.

The variable reactor further includes an operation unit 400 for calculating an inducible reactance for improving the power factor, and the driving unit 300 drives the driving unit 300 in accordance with the induced reactance calculated from the operation unit 400, 100 and the core unit 200 are overlapped with each other.

In addition, the operation unit 400

The operation unit 400

: 권선이 감긴 보빈의 길이,

: 철심과 공심의 상호인덕턴스,

: 공기중 투자율,

: 공기중 철심의 비투자율)Where b is the length of the bobbin in which no iron core is present, N is the number of turns of the coil,

: Length of the bobbin with the winding wound,

: Mutual inductance between core and core,

: Permeability in air,

: Specific permeability of iron core in air)

Is used to calculate the induced reactance for improving the power factor.

According to the variable reactor according to the embodiment of the present invention, there is an effect that the reactance value can be changed linearly by varying the section where the core portion and the core portion are overlapped.

Further, the iron core portion is formed into a columnar shape, and the iron core portion or the core portion is simply linearly moved, thereby simplifying the structure for linearly varying theactactance to a desired reactance value.

Further, by forming the iron core portion in the shape of a bar having a circular arc with a center line and rotationally moving the iron core portion or the core portion, the length in the direction in which the iron core portion and the core portion are longest can be reduced.

Further, by forming the iron core portion in the form of a bar having a spiral center line and rotating the iron core portion or the core portion by a spiral, the length in the direction in which the iron core portion and the core portion are longest can be further reduced.

In addition, by varying the section in which the core section and the core section are overlapped by driving the motor, it is possible to precisely control the section where the core section and the core section overlap.

In addition, there is an effect that the reactance which can improve the power factor by the operation unit to obtain the best efficiency, and to control accordingly.

1 is a block diagram of a variable reactor according to one embodiment of the present invention;
FIG. 2 is a conceptual view of an embodiment of the core portion and the iron core portion of FIG. 1. FIG.
3 is a conceptual view of another embodiment of the core portion and the iron core portion of FIG.
FIG. 4 is a conceptual view of another embodiment of the core portion and the iron core portion of FIG. 1; FIG.
5 is a block diagram of a variable reactor according to another embodiment of the present invention;

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, .

On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the term "comprises" or "having ", etc. is intended to specify the presence of stated features, integers, steps, operations, elements, parts, or combinations thereof, And does not preclude the presence or addition of one or more other features, integers, integers, steps, operations, elements, components, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be construed as ideal or overly formal in meaning unless explicitly defined in the present application Do not.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concept of the term appropriately in order to describe its own invention in the best way. The present invention should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention. Further, it is to be understood that, unless otherwise defined, technical terms and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted. The following drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the following drawings, but may be embodied in other forms. In addition, like reference numerals designate like elements throughout the specification. It is to be noted that the same elements among the drawings are denoted by the same reference numerals whenever possible.

FIG. 1 is a block diagram of a variable reactor according to an embodiment of the present invention. FIG. 2 is a conceptual diagram of an iron core unit and a core unit of FIG. 1, and FIG. FIG. 4 is a conceptual view of another embodiment of the core and the iron core of FIG. 1, and FIG. 5 is a block diagram of a variable reactor according to another embodiment of the present invention.

1, a variable reactor according to an embodiment of the present invention is a variable reactor that exhibits a reactance that is inductance with respect to a change of an alternating current or a current due to the accumulation of electromagnetic energy. The variable reactor includes an iron core 100, (200) and a driving unit (300).

A reactor is an electrical device that exhibits a reactance that is inductance to a sudden change in alternating current or current due to the accumulation of electromagnetic (electromagnetic) energy. It introduces an inductive reactance to a circuit in a power transformer and a distribution transformer And it is mainly used to wind a number of windings on an iron core.

Since the reactor is a reactive power device, [VAR] is used as a unit, and it is often referred to as a few amperes [A] and a few [mH].

The [mH] of the reactor is originally [H], but it is too large, so [mH] may be used as a preheater or [μH] micro henna.

The capacity Px of the reactor is as follows.

(Single phase) Px = I ² · ω · L [VAR] (where ω = angular velocity 2πf, L = inductance)

(3-phase) Px = 3 · I ² · ωL [VAR] (where ω = angular velocity 2πf, L = inductance)

In the electric circuit, only the resistance interferes with the direct current, but the alternating current has the resistance component which interrupts the current in addition to the resistance because the direction and the amount change in each time. This resistance component is called reactance, and there are two types of reactance: inductive reactance by inductive action and capacitive reactance by capacitive action. Each unit is expressed in ohms (Ω). Impedance (unit: Ω) is a combination of resistance and reactance.

In other words, reactance refers to an action that produces an amplitude change between the voltage and current for an alternating current. It is generally defined as the imaginary part of the AC resistance () expressed in (complex number).

More specifically, in an alternating current circuit, a resistance is represented by an impedance (denoted by Z). The elements of this impedance are the resistance (R) and the reactance (X) and the unit is ohms (Ω). Reactance reactance also interferes with the flow of current like a resistor, but appears only in the case of an alternating current. The phase of the connected voltage and the flowing current are different from each other. The reactance by the inductor is referred to as induction reactance, and the reactance by the capacitor is referred to as capacitance reactance.

The AC voltage V is expressed mainly by the sinusoidal wave with the maximum voltage Vm and the angular frequency ω (2πf, π = 3.14, f = frequency (unit Hz)

V = Vmsin (wt)

When a resistor is connected here, the current is controlled by Ohm's law (V (voltage) = I (current) R (resistance)

I = (Vm / R) sin (wt)

And the phase, that is, the shape varying with time, is equal to the supplied voltage and the flowing current. However, the effect of the reactance (X) is the same as that of the resistor in the case where the maximum current is given by Vm / X, but the current is delayed by 90 degrees (ground current) when the phase is inductive reactance, (Forward current).

This is because the phenomenon that impedes current flow is different in resistance and reactance. In the case of resistors, electrons are generated by the current flow itself, which is generated by the energy of heat, which strikes the molecules as they flow. Reactance, on the other hand, is caused by the nature of the circuit elements that cause reactance to maintain their electrical state. That is, the inductive reactance is the energy by the magnetic field, and in the case of the capacitive reactance, the electric state is maintained as the energy by the electric field. For example, in the case of an inductive reactance, the inductor (coil) has a property that the current flow is constant, so that when the AC flows, it interferes with the change of the current to have a resistance property. In the case of the capacitive reactance, It prevents the voltage from changing and shows the resistance property. This direction is interrupted by the flow of the AC, so the phase changes.

The air-core reactor has a constant reactance value regardless of the current level, and can be used as a high frequency reactor or a current limitting reactor.

L = N ² Dφ * 10 ^-9 (D: average diameter of winding (cm), N: winding number of winding)

An iron core reactor can be divided into an iron core with an iron core inserted into an iron core reactor, and a iron core with a gap and a gap free structure.

When a stratified core is inserted into an air core reactor, the magnetic permeability increases, so the amount of magnetic flux flowing between the winding and the chain increases and the reactance increases.

In other words, the iron core reactor becomes compact to obtain reactance like air core type.

Because of the magnetic saturation phenomenon in the iron core, it is impossible to keep the reactance constant at a wide range of currents.

The iron core reactor without Gap is reduced in volume and weight, and the reactance value changes significantly due to the load current due to the magnetic nonlinearity of the iron core. Therefore, it can be used for a special saturable reactor that changes the reactance according to DC excitation control.

The saturable reactor applies a DC excitation to the iron core of the reactor to change the reactance value widely. That is, when the control (DC) current is varied in the reactor, the current is substantially constant even though the voltage of the AC winding changes.

Therefore, it is suitable when the load current needs to be kept constant even if the impedance of the load changes, and the large AC power can be controlled by the fine DC power, so that the AC power can be used for the voltage adjustment of the alternator.

An iron core reactor with a gap has a gap between the core and the iron core by installing a gap in the middle of the core of the iron core. The reactance can be kept constant like an air core reactor when the current is not saturating the iron core. It can be used as a series reactor of SOHO reactor and AC / DC circuit.

The reactance can be lowered by several% for the current saturated by the iron core, and the impedance within the range in which the iron core is not saturated is

L = 4? N ² Q / ((l / μs) + lg) * 10 ^-9 (H)

(N: number of turns, Q: iron core cross section (cm 2), l: length of iron core (cm), μs: magnetic permeability of iron core,

. ≪ / RTI >

The iron core reactor with gaps includes power shunt reactors, Arc Suppressing Reactors, neutral reactors, starting reactors, and smoothing reactors.

In cable system, it is possible to use power shunt reactors that are easier to maintain and more economical than synchronous shunt reactors in order to solve the problem that the system voltage increases due to the increase of system voltage due to light load current.

When the line of the transmission line is arc grounded, the charge current is concentrated at the ground point through the earthquake resistance. If the arc is continued, the current is 90 ° ahead of the phase voltage on the ground. Connect the reactor between the neutral point of the transformer and the earth Arc Suppressing Reactor can be used to reduce the arc current by eliminating the charging current at the ground point by supplying a current 90 ° out of phase with the ground point → ground → reactor → closed loop on transformer ground.

In case of long-distance transmission line, in order to prevent abnormal voltage rise when 1 line is grounded, a neutral reactor used for neutral point grounding by connecting resistor and reactor in series can be used.

Starting induction motors and synchronous motors may be used in series with starting coils and starting reactors may be used to reduce the starting current and to reduce the heating and mechanical power of the armature coils.

A smoothing reactor may be used in order to reduce the pulsation rate of the direct current inserted into the direct current side of the rectifying device.

The iron core 100 is formed in a predetermined shape.

The iron core unit 100 may be formed in various shapes as an important factor for determining a basic shape of a variable reactor and a movement path to be controlled for reactance control according to an embodiment of the present invention.

At this time, the iron core 100 may be formed in a columnar shape, and the shape of the core 200 described below may be formed to correspond to the shape of the iron core 100. 2)

For example, when the iron core 100 is formed in a cylindrical shape, the core portion 200 may have a core portion 200 having an air core greater than the diameter of the iron core portion 100. That is, the iron core 100 and the core 200 may be formed in a columnar shape.

The core part 200 may be formed in a shape of a bar having an arcuate center line, and the shape of the core part 200 described later may be formed in a shape corresponding to the shape of the iron core part 100 (See Fig. 3)

For example, when the iron core 100 is formed into a circular bar shape having a circular arc with a center line, the core portion 200 may include a core portion 200 having an air core greater than the diameter of the iron core portion 100, Can be formed. That is, the iron core 100 and the core 200 may be formed in a arc shape.

The core portion 200 may be formed in a shape of a bar having a spiral center line, and the shape of the core portion 200 may be formed in a shape corresponding to the shape of the core portion 100 (See Fig. 4)

For example, when the iron core 100 is formed into a circular bar shape having a spiral centerline, the core 200 may include a core portion 200 having an air core greater than the diameter of the iron core 100, Can be formed. That is, the iron core 100 and the core 200 may be formed in a spiral shape.

The present invention is not limited to the above embodiments, and any shape may be used as long as it can vary the section where the iron core 100 and the core 200 are overlapped with each other. Of course.

The core part 200 has a moving space (air core) of the iron core part 100 formed on the center line, and the coil is wound.

That is, the coil is wound so that the core portion 200 is formed such that the core portion 100 can move.

The driving unit 300 moves the iron core 100 or the core unit 200 to vary a section where the core unit 100 and the core unit 200 overlap.

The driving unit 300 may drive the core unit 100 to vary the interval between the core unit 200 and the core unit 200 or may drive the core unit 200 to move the core unit 200 And the core section 200 are overlapped with each other or the core section 200 is driven by driving the core section 100 and the core section 200, .

That is, in the variable reactor according to the embodiment of the present invention, the iron core unit 100 or the core unit 200 is moved to vary the section in which the core unit 100 and the core unit 200 overlap. This is to linearly vary the reactance.

At this time, the driving unit 300 may vary the section in which the core unit 200 and the core unit 100 are overlapped by driving the motor.

That is, a motor may be used as the driving unit 300, and the iron core unit 100 or the core unit 200 may be moved by connecting a motor to the iron core unit 100 or the core unit 200.

In a reactor used for high-voltage transmission, power generation, and power distribution, such as a variable reactor substation, a power plant, etc. according to an embodiment of the present invention, a variable reactor capable of adjusting (varying) reactance by a linear method by adjusting the length of an iron core inserted into the coil Can be provided.

It is also possible that only the air core section is formed in the reactor itself or only the iron core section is formed depending on the position of the iron core, or it can be divided into the air core section and the iron core section.

When only the air-core section is formed, the reactance can be obtained by a method of obtaining the reactance of the air-core reactor,

When only the iron core section is formed, the reactance can be obtained by a method of obtaining the reactance of the iron core reactor,

When the iron core part 100 is partially inserted into the coil part 200, it is assumed that the core core reactor and the iron core reactor are connected in series and the reactance is obtained by a method of obtaining the reactance of the core reactor and a method of obtaining the reactance of the iron core reactor. Can be obtained.

5, the variable reactor according to an exemplary embodiment of the present invention further includes an operation unit 400 for calculating an inductive reactance for improving the power factor, and the driving unit 300 includes the operation unit 400 The core unit 200 and the core unit 200 may be overlapped with each other in accordance with the induced reactance calculated from the core unit 200 and the core unit 200. [

That is, the operation unit 400 can calculate the reactance for maximizing the efficiency based on the information (sensed) from the line to which the reactor is connected, and can automatically control the reactance.

The power transmission line supplies power to a long distance of several tens of kilometers, so that a phase-ineffective current is generated due to the consumption current. The shunt reactor is installed in parallel with the line to appropriately adjust the balance of reactive power.

If a shunt reactor with a constant capacity is installed at the front end of the line, the reactive current is absorbed only by the rated capacity. Therefore, the reactive current must be increased or decreased especially when the load is heavy. It is a way to maximize. However, if the proper capacity is not selected, the large reactive current is consumed in the reactor, the line loss increases and the power factor becomes lower. Therefore, it is necessary to understand the system and accurately calculate the capacity.

At this time, the operation unit 400

The operation unit 400

: 권선이 감긴 보빈의 길이,

: 철심과 공심의 상호인덕턴스,

: 공기중 투자율,

: 공기중 철심의 비투자율)Where b is the length of the bobbin in which no iron core is present, N is the number of turns of the coil,

: Length of the bobbin with the winding wound,

: Mutual inductance between core and core,

: Permeability in air,

: Specific permeability of iron core in air)

To calculate the induced reactance for improving the power factor.

The improvement of the power factor means that the power factor is increased. The fact that the power factor is large means that the active power is close to the apparent power. In the case of the load side (consumer side) ), It is possible to flow a small amount of current to the same load, so that there is an advantage that the voltage drop is small and the effect of the use of the power supply facility is increased.

AC power can not be expressed only by the product of the rms value of voltage and current. However, since the shape of the voltage current is the power, VI is the apparent power and the unit is the volt-ampere. Multiplying the apparent power VI by a coefficient of cos [theta] yields alternating current power. This cos θ is called a power factor in terms of the power multiplied by power, and abbreviated as p · f.

The power factor is related to power / apparent power (P / VI * cos?).

Here,? Is a phase difference between a voltage and a current, and is an angle of an impedance or an admittance, and thus has a range of -90 占? Cos?? 90 占 0? P 占 1 1. ? = 90 占 and p 占 = = cos? and? = 0 占 and p 占 = = cos? = 1.

The power system load is generally composed of a combination of resistance (R) and inductive reactance (XL). The voltage and current are phase differences by cos θ depending on the impedance. There is an advantage of reducing descent.

Electricity and electric heating load in electric facilities generally have good power factor, but power factor of electric motor is not good, which causes voltage fluctuation and power loss increase. Therefore, when a capacitor, etc. are connected in parallel with the load, the power factor is improved because the phase current flows.

When the power factor is improved,

From the power supply side, the power system can be stabilized, the power loss can be reduced, and the facility capacity can be efficiently operated, which can reduce the investment cost and the maintenance cost.

The power factor is improved in the power-consuming side (the consumer), so that the load current is reduced and the facility capacity is available even in the same equipment. Improving the power factor also reduces the line current and reduces the voltage drop in the line.

As a whole, power factor improvement is beneficial in terms of power companies and consumers. In particular, electric power companies are rationalizing their facilities. Therefore, a power factor surcharge system is applied to basic charges in order to promote power factor improvement of customers.

The shunt reactor consumes the reactive current when the supply amount of the reactive current exceeds the consumption amount. It is installed for the purpose of suppressing the secondary voltage rise of the front end transformer and preventing the deterioration of the electric equipment due to the severe phase operation when the load is low at light loads such as holidays and nighttime.

Although the separation reactor is described above as an example, the present invention is not limited thereto, and it goes without saying that the present invention is applicable to all reactors for varying the reactance in order to improve the efficiency of the reactor.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100: iron core part
200: core part
300:
400:

Claims (7)

1. A variable reactor exhibiting a reactance that is inducible with respect to a change in alternating current or current by accumulation of electromagnetic energy,
An iron core 100 formed in a predetermined shape;
A core part (200) in which a moving space of the iron core part (100) is formed on a center line and in which a coil is wound; And
A driving unit 300 for moving the iron core unit 100 or the core unit 200 to vary a section in which the core unit 100 and the core unit 200 overlap each other;
Lt; / RTI >
The variable reactor
An operation unit 400 for calculating an inductive reactance for improving the power factor;
Further comprising:
The driving unit 300
The core unit 200 may vary in the section where the core unit 100 and the core unit 200 overlap with each other in accordance with the induced reactance calculated from the operation unit 400,
The operation unit 400

Where b is the length of the bobbin in which no iron core is present, N is the number of turns of the coil,

: Length of the bobbin with the winding wound,

: Mutual inductance between core and core,

: Permeability in air,

: Specific permeability of iron core in air)
Is used to calculate the induced reactance to improve the power factor.
The method according to claim 1,
The iron core portion 100
And is formed in a columnar shape.
The method according to claim 1,
The iron core portion 100
And the center line is formed in a bar shape having an arc shape.
The method according to claim 1,
The iron core portion 100
And the center line is formed into a bar shape having a spiral shape.
The method according to claim 1,
The driving unit 300
And the section in which the core unit (200) and the core unit (100) are overlapped by the driving of the motor is changed.
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