KR101211889B1 - Intelligent apparatus for controlling zero harmonic filter and method for controlling the same - Google Patents

Abstract

The present invention relates to an apparatus for controlling an image harmonic filter, and determines whether a separation condition of an image harmonic filter connected on R, S, T, and N is determined, and if it is determined that the separation condition corresponds to the separation condition, the image harmonic filter is determined as R. A separation condition determination unit for electrically separating from the S and T phases; And an imaging determination unit for diagnosing whether an image harmonic filter is electrically disconnected from the R, S, and T phases in a predetermined manner. The present invention is to isolate the zigzag connection transformer electrically from the R, S, T phase when the disconnection condition of the zigzag connection transformer connected to the R, S, T, N phase, and to diagnose whether there is a power phase loss in the separated state. As a result, it is possible to accurately determine whether or not an image-side harmonic is installed on the power source side.

Description

Intelligent image harmonic filter control device and method {INTELLIGENT APPARATUS FOR CONTROLLING ZERO HARMONIC FILTER AND METHOD FOR CONTROLLING THE SAME}

The present invention relates to an intelligent image harmonic filter control device and a control method thereof, and more particularly, to an intelligent image harmonic filter control device and a control method thereof capable of accurately diagnosing the presence of power phase in an environment in which an image harmonic filter is installed. .

As the spread of devices expands, neutral-phase harmonic currents in three-phase four-wire distribution systems cause various types of disturbances. Harmonics generated from non-linear loads such as UPS, inverters, PCs, and lighting equipment flow into the power system, causing malfunctions and reduced lifespan of electrical equipment. The harmonics in the power system are: i) normal harmonics with frequencies equal to (3n + 1) multiples of the fundamental frequency; ii) inverse harmonics with frequencies corresponding to (3n-1) multiples of the fundamental frequency; 3n) There is an image harmonic with a frequency corresponding to multiples. Dual image harmonics are superimposed on the neutral, resulting in triple peaks. In particular, the image harmonics may cause a fire due to overheating of the neutral wire due to the overlapping characteristic of the neutral wire (N phase). In particular, the increase in iron loss of the noise generating device adversely affects the power equipment. Therefore, KEPCO manages harmonics according to the Harmonics Management Standard (effective from July 2010). Therefore, an image harmonic filter is provided on the harmonic source side to reduce image harmonics. Image harmonic filters can be broadly divided into active, passive, and soft type. The active type can eliminate the image harmonics by canceling the harmonics of the load current by the inverse harmonics of the compensation current. The passive type is composed of LC, and by absorbing the harmonic components in the load current, it is possible to block the flow of harmonic components into the load. The passive type is distinguished from the active type in that a separate external power source is not required to remove harmonic components. The softly immutable harmonic filter can remove the image harmonic components by circulating the image current in the filter using a zig-zag connection transformer. Soft expressions can be included in a broad passive type in that no separate power source is used to filter the image harmonics. Hereinafter, the term "image harmonic filter" is intended to include a broad passive type. Such an image harmonic filter is preferably installed in the distribution panel that is the position closest to the load which is the source of harmonics. The image harmonic filter is installed on the load side to remove the image harmonics generated by the nonlinear load. The image harmonic filter is connected to the normal line.

Due to the characteristics of the zig-zag phase-transformation transformer applied to the image harmonic filter, voltage is applied to the line formed through the zig-zag transformer even when the power supply side of any of the three phases is phase-deformed. In general, when the phase of the power supply side is determined, it is determined that the phase of the power supply side if the voltage is less than the set value for each phase of the three phases. However, even when an image occurs on the power supply side in the state in which the zigzag transformer is connected, a voltage is applied to the image formed through the zigzag transformer, and thus, even when an image occurs on the power supply side, it may be determined that the image is not formed.

That is, in the related art, there is a problem in that it is impossible to accurately determine whether the power phase is formed in an environment in which an image harmonic filter is installed.

Accordingly, an object of the present invention is to provide an apparatus and method for controlling an image harmonic filter capable of accurately determining whether or not an image is formed on the power supply side in an environment in which an image harmonic filter is installed.

Another object of the present invention is to provide an apparatus and method for controlling an image harmonic filter capable of quickly diagnosing whether an image is lost when an event related to an image occurs.

Other objects of the present invention will be readily understood through the following description of the embodiments.

Image harmonic control apparatus according to an embodiment of the present invention for achieving the above object is determined whether the separation condition of the image harmonic filter connected on the R, S, T, N, and corresponds to the separation condition If it is determined that the image harmonic filter is electrically separated from the R, S and T phase, and the image harmonic filter is electrically separated from the R, S and T phase to diagnose whether there is a power-side phase loss in a predetermined manner A separation condition determining unit controlling the image forming determining unit; And an opening / closing unit which is turned off in response to determining that the separation condition determination unit corresponds to the separation condition.

Here, the separation condition determination unit detects a current on at least one conductor wound around the image harmonic filter connected to the R, S, T, and N phases, and determines whether a harmonic component of the detected current falls within a preset range. If it is determined that the harmonic component of the detected current falls within a preset range, it may be determined that the separation condition corresponds to the separation condition. In contrast, the separation condition determination unit may determine that the separation condition corresponds to the separation condition when the preset period is reached.

The imaging determination unit may determine whether the imaging is performed by using a voltage on at least one of the R, S, and T phases while the image harmonic filter is electrically separated from the R, S, and T phases.

According to another aspect of the present invention, there is provided a method of controlling an image harmonic filter, including determining whether a separation condition of an image harmonic filter connected to R, S, T, and N is applicable; In a step of determining whether the separation condition is applicable, electrically separating the image harmonic filter from the R, S, and T phases when it is determined that the separation condition corresponds to the separation condition; And causing the image harmonic filter to be diagnosed as a power-side phase loss in a predetermined manner in a state in which the image harmonic filter is electrically separated from the R, S, and T phases.

Here, the current is detected on at least one conductor wound around the image harmonic filter connected to the R, S, T, and N phases, and it is determined whether a harmonic component of the detected current falls within a preset range. When the harmonic component of the current is within a predetermined range, it may be determined that it corresponds to the separation condition. On the contrary, when the preset period is reached, it may be determined to correspond to the separation condition.

In addition, the imaging may be determined by using the voltage of at least one of the R, S, and T phases while the image harmonic filter is electrically separated from the R, S, and T phases.

As described above, in the present invention, when the zigzag connection transformer corresponds to the separation condition of the zigzag connection transformer connected to the R, S, T, and N phases, the zigzag connection transformer is electrically disconnected from the R, S, and T phases, and the power supply side in the separated state. By diagnosing the imaging, it is possible to accurately determine whether the power supply-side imaging is performed in an environment in which the image harmonic filter is installed.

In addition, the present invention, if the harmonic content of the current on the at least one conductor wound on the zigzag connection transformer connected to the R, S, T, N phase falls within a preset range, the zigzag connection transformer is electrically connected from the R, S, T phase. By disconnecting and diagnosing whether there is a power supply side open phase in the separated state, it is possible to quickly diagnose the open phase when an event related to the open phase occurs.

1 shows an installation state diagram of an image harmonic filter control device according to an exemplary embodiment of the present invention.
2 is a flowchart of a method of controlling an image harmonic filter according to an exemplary 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 should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for like elements in describing each drawing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be.

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 example embodiments only and is not intended to be limiting of the present invention.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

The present invention is to isolate the zigzag connection transformer electrically from the R, S, T phase when the disconnection condition of the zigzag connection transformer connected to the R, S, T, N phase, and to diagnose whether there is a power phase loss in the separated state. As a result, it is possible to accurately determine whether or not an image-side harmonic is installed in the environment where the image harmonic filter is installed.

Hereinafter, an image harmonic filter control device according to an exemplary embodiment of the present invention will be described with reference to FIG. 1. 1 shows an installation state diagram of an image harmonic filter control device according to an exemplary embodiment of the present invention. In order to make the gist of the present invention clear, the description of the well-known technique is omitted or simplified.

Referring to FIG. 1, the apparatus for controlling image harmonics 1000 may include an opening and closing unit 1100, a separation condition determiner 1200, and an image determination determiner 1300. The opening and closing unit 1100, the separation condition determiner 1200, and the image forming determiner 1300 may be implemented as separate modules. In the image harmonic filter control device 1000, the opening and closing unit 1100 and the separation condition determining unit 1200 are formed as one module, and the image harmonic filter control device 1000 is installed in the distribution panel, thereby making the image harmonic filter control device ( The output of any one of the 1000 may be connected to the imaging determination unit 1300 formed as a separate module. In this case, according to a control signal outputted in response to the image harmonic filter control device 1000 determining that the image harmonic filter control unit corresponds to the image harmonic filter separation condition, the image determination unit 1300 determines that the image harmonic filter is R, S, and T phases. In the electrically separated condition, the operation of the imaging determination unit 1300 may be set to determine whether the power-side imaging is performed. In FIG. 1, the R, S, T, and N phases can supply power to a load (not shown) in a three-phase four-wire manner. For example, the R, S, T, and N phases may be busbars in the distribution panel.

The opening and closing unit 1100 may be implemented as a semiconductor switching element or a relay. As long as it can perform a switching function may correspond to the opening and closing unit 1100 of the present invention. The open / close unit 1100 performs an off operation according to a control signal output in response to the separation condition determining unit 1200 determining that the separation condition corresponds to the separation condition, and thus, the image harmonic filter 100 (in other words, Zigzag connection transformers) can be electrically isolated from the R, S, T and N phases. In this case, all three conducting wires connecting the R, S, T phase and the image harmonic filter 100 may be opened. Unlike FIG. 1, the opening / closing unit 1100 may be connected to the imaging determination unit 1300. In this case, according to the control of the imaging determination unit 1300, the open / close unit 1100 may perform an off operation in response to the separation condition determining unit 1200 determining that the image corresponds to the image harmonic filter separation condition. In addition, when it is determined that the imaging decision unit 1300 is imaging, the open / close unit 1100 may maintain an OFF state under the control of the imaging determination unit 1300. When the open / close unit 1100 is in the turned-on embodiment when the open image determining unit 1300 completes sampling of the voltage used to determine the open phase, the open / close unit 1100 may determine that the open / close unit 1100 determines that the open image is the open phase. Can be turned off. As long as the opening / closing unit 1100 performs an off operation in response to the separation condition determining unit 1200 determining that it corresponds to the image harmonic filter separation condition, the opening / closing unit 1100, the separation condition determining unit 1200, and the imaging determination unit are performed. There may be no limitation in the circuit structure between the 1300, and there may be no limitation in the subject controlling the operation of the opening and closing unit 1100. In addition, the circuit structure between the open / close unit 1100, the separation condition determiner 1200, and the open / close determiner 1300 as long as the open / close unit 1100 is in an off state in response to the determination of the open image determiner 1300 to be an open phase. There may be no limitation, and there may be no limitation on the subject controlling the operation of the opening and closing unit 1100.

The separation condition determiner 1200 determines whether a separation condition of the image harmonic filter 100 connected to R, S, T, and N is applicable, and if it is determined to correspond to the separation condition, the image harmonic filter 100 is R. It can be electrically separated from the S and T phases. Here, the separation condition may be a cycle. That is, the separation condition determination unit 1200 may determine that the separation condition corresponds to the separation condition when the preset period is reached, and may output a control signal to the open / close unit 1100 to perform the off operation. In the case where a preset period is used as the separation condition, the current detector 1400 may be omitted in FIG. 1.

However, when the preset period is a separation condition, if the preset period is set long, the image harmonic filter cannot be separated from the R, S, and T phases immediately when the power phase image formation occurs. In order to compensate for this, when the preset period is set short, since the separation of the image harmonic filter 100 is repeated at a fast cycle, the filtering efficiency by the image harmonic filter 100 may be reduced.

In contrast, the separation condition determiner 1200 detects a current on at least one lead wound around the image harmonic filter connected to R, S, T, and N, and determines whether a harmonic component of the detected current falls within a preset range. If it is determined whether or not the harmonic component of the detected current falls within a predetermined range, it is determined that it corresponds to a separation condition, and the image harmonic filter may be electrically separated from the R, S, and T phases. Here, various methods may be used to determine whether the preset range is included, and specific details are as follows.

The experimental results in the case where the image harmonic filter is installed and the image formation occurs while the load is connected are shown in Table 1 below.

division R phase S phase T phase N phase Harmonics for 6A
Apply filter
(R phase imaging,
Load connection) Harmonic Open phase
(I'm) Open phase
(after) Open phase
(I'm) Open phase
(after) Open phase
(I'm) Open phase
(after) Open phase
(I'm) Open phase
(after) Current 0.3 2.7 0.3 2.7 0.3 2.7 0.8 8 3rd harmonic 0.2 0.4 0.2 0.5 0.2 0.4 0.6 1.4 5 Harmonics 0.1 0.1 0.1 0.1 0.1 0.1 0.3 0.3 7harmonics 0 0.4 0 0.4 0 0.3 0.7 1.1 9 Harmonics 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2

* Current: fundamental + harmonic

In Table 1, R phase, S phase, T phase, and N phase refer to conducting wires wound on the image harmonic filter, respectively, connected to the power supply side R, S, T, and N phases. The data in Table 1 shows the result of R phase missing when a 6A image harmonic filter is installed and the load is connected. Referring to Table 1, it can be seen that while the total current on the image harmonic filter increases significantly during imaging, the increase of harmonics is relatively small. This is because the image harmonic filter acts as a power source during the imaging phase, so the total current of the filter side increases, but the harmonic does not increase as the total current increases. From these results, it can be seen that in the environment in which the image harmonic filter is installed, the possibility of power-side imaging can be determined as THD (Total Harmonic Distortion). That is, when the THD suddenly increases, the separation condition determining unit 1200 determines that power-side imaging has occurred, in other words, it is determined that the image harmonic filter separation condition corresponds, and the image harmonic filter 100 is R, S, It can be electrically separated from the T phase. THD may be calculated for a preset frequency band, for example, 2 to 10 harmonics. The frequency band used for calculating the THD can be easily changed by the designer. It goes without saying that one harmonic can be used to calculate the THD. Alternatively, without using the THD, it may be determined whether or not the power-side phase imaging with the ratio of the specific harmonics and the total current. As shown in Table 1, the ratio between specific harmonics and the total current varies significantly before and after the phase, and it is possible to easily determine the possibility of power-side phase loss or the condition of separation by using the ratio of the specific harmonics and the total current. . That is, when the ratio between the specific harmonics and the total current is less than or equal to a predetermined level, it may be determined that the phase is formed. Conversely, if the ratio between the total current and a particular harmonic exceeds a certain level, it can be determined that it is an image.

In summary, in the light of the above experimental results, i) when the THD is reduced below the preset level (no harmonics used to calculate the THD, no harmonic range limitation) ii) the ratio between the total current and the specific harmonic When exceeded (the number of specific harmonics is not limited, and certain harmonics can be image harmonic) ⅲ) When the ratio of specific harmonics to full current is below the preset level ⅳ) The currently detected THD is higher than the THD detected immediately before. When lowering below the preset level 레벨) When the ratio between the current detected current and the specific harmonic is increased more than the preset level from the ratio of the previous detected current and the specific harmonic ⅵ) The specific detected harmonic and all current When the ratio of to belongs to at least one of the times when the ratio of the specific harmonics detected from the ratio of the previous harmonic and the total current is more than the predetermined level, that is, the phase-side phase imaging, that is, the separation It may be determined that the condition corresponds.

Here, iii) when the THD is reduced below the preset level (the number of harmonics used to calculate the THD, there is no limit to the harmonic range) ii) when the ratio between the total current and the specific harmonic exceeds the preset level (the specific harmonic The number is unlimited, and certain harmonics can be image harmonic) ⅲ) When the ratio between specific harmonics and full current is below the preset level 현재) When the currently detected THD is lowered below the preset level than the previously detected THD Iii) when the ratio between the current detected current and the specific harmonics is increased by more than the preset level from the ratio of the detected current and the specific harmonics above. As long as it is determined that the phase of the power supply is phase-decreased from the ratio between the ratio of the electric current and the electric current to the predetermined level, the mathematical method for determining the No. For example, when determining the amount of harmonics, the magnitude of the harmonics, otherwise, a squared value of the harmonic magnitudes may be used.

The experimental results when the image harmonic filter is installed and the image formation occurs when the load is not connected are shown in Table 2 below.

division R phase S phase T phase N phase Harmonics for 3A
Apply filter
(R phase imaging,
Without load) Harmonic Open phase
(I'm) Open phase
(after) Open phase
(I'm) Open phase
(after) Open phase
(I'm) Open phase
(after) Open phase
(I'm) Open phase
(after) Current - - - - - - 0.4 0.1 3rd harmonic - - - - - - 0.3 0 5 Harmonics - - - - - - 0.1 0 7harmonics - - - - - - 0 0 9 Harmonics - - - - - - 0.3 0

* Current: fundamental + harmonic

In Table 2, R phase, S phase, T phase, and N phase refer to conducting wires wound on the image harmonic filter, respectively, connected to the power supply side R, S, T, and N phases. The data in Table 2 is the result of the case where the R phase is missing while the 3A image harmonic filter is installed and the load is not connected. It can be seen that harmonics are very reduced when no load is connected and an open phase occurs. From these results, it is possible to judge whether or not the power supply side is missing by the harmonic amount when there is no load. That is, if harmonics are below a certain level, it can be determined that it is an image. Alternatively, when the harmonic amount detected at present is reduced to a preset level or lower than a harmonic amount detected immediately before, for example, by a preset ratio or a preset difference, it may be determined that the power-side phase imaging is performed.

In other words, when the load is not connected, i) when harmonics are below the preset level (the number of harmonics and no band limit) ii) when the currently detected harmonics are reduced below the preset level than the immediately detected harmonics. When belonging to at least one of, it is the power phase-side imaging, that is, may correspond to the image harmonic filter separation conditions. In this case, the harmonics used to determine whether the power supply phase is formed may be harmonics of a preset band, at least one preset harmonic, and at least one preset harmonic file. Iii) When harmonics are below the preset level. Ii) As long as the current detected harmonics are reduced to below the preset level than the last detected harmonics, the method of judging that it is the power phase imaging is limited. There is no For example, when determining the amount of harmonics, the magnitude of the harmonics, otherwise, a squared value of the harmonic magnitudes may be used.

In light of the results of the experiment, the separation condition determiner 1200 may determine whether the separation condition is applicable in consideration of the case where the load is connected and the case where the load is not connected. That is, i) when the THD is reduced below the preset level (the number of harmonics used to calculate the THD, no limitation on the harmonic range), and ii) when the ratio between the total current and the specified harmonic exceeds the preset level The number is unlimited, and certain harmonics can be image harmonic) ⅲ) When the ratio between specific harmonics and full current is below the preset level 현재) When the currently detected THD is lowered below the preset level than the previously detected THD Iii) when the ratio between the current detected current and the specific harmonics is increased by more than a predetermined level from the ratio of the current detected current and the specific harmonics. When it belongs to at least one of the times when the ratio decreases from the ratio between the electric current and the predetermined current or more, it may be determined that the separation condition corresponds (first determination).

Then, the separation condition determining unit 1200 includes: i) when harmonics are lower than or equal to the preset level (the number of harmonics and no band limitation); ii) when the currently detected harmonics are lower than or equal to the preset harmonics detected. When it belongs to at least any one of can be determined to correspond to the separation conditions (second determination). Unlike the above, the voltage on the image harmonic filter 100 can be used to determine whether the separation condition. In this case, a PT (Potential Transformer) may be used for voltage detection.

The separation condition determiner 1200 may perform the first and second judgments sequentially or in parallel. In this case, the separation condition determination unit 1200 may be implemented as a separate module, the module for the first determination and the module for the second determination.

The imaging determination unit 1300 may determine whether the imaging is performed in response to the separation condition determination unit 1200 determining that the image corresponds to the image harmonic filter separation condition. The imaging determination unit 1300 may determine whether the imaging is performed using a known method. For example, the imaging determination unit 1300 may determine that the imaging has occurred when the voltage of any one of the R, S, and T phases is reduced below a preset level, for example, 70% or less of the normal value. have. The image determination unit 1300 may be manufactured as a separate module. An imaging determination unit 1300 installed in an existing system may be used. In this case, any one input terminal of the imaging determination unit 1300 may be connected to any one output terminal of the separation condition determining unit 1200. When the image determination unit 1300 receives a control signal output in response to the separation condition determination unit 1200 determining that the separation condition corresponds to the separation condition, the image determination unit 1300 determines whether the image harmonic filter 100 is in the separated state. can do. In addition, the imaging determination unit 1300 may perform an operation of periodically diagnosing the imaging using at least one voltage among R, S, and T phases according to a predetermined cycle.

The current detector 1400 may detect a current on at least one conductor wound around the image harmonic filter 100, and transmit the current to the separation condition determiner 1200. As a current detector 1400, a CT (Current Transformer), for example, a clamp CT may be used. The current detector 1400 detects the current in a non-contact manner, thereby determining whether the image harmonic filter 100 is electrically disconnected from the R, S, and T phases, that is, whether or not a power supply-side phase is formed. Can be.

As such, the imaging determination unit 1300 diagnoses the imaging in a state in which the image harmonic filter 100 is electrically separated from the R, S, T, and N phases, and thus, the imaging determination may be more accurate.

In addition, the imaging determination unit 1400 diagnoses the imaging in a state in which the image harmonic filter 100 is electrically separated from the R, S, and T phases when the imaging condition is suspected by the separation condition determination unit 1200. In this case, it is possible to precisely diagnose the missing phase immediately when the missing phase occurs.

In addition, since the current detection unit 1400 is implemented by CT, it is easy to install and whether or not the imaging harmonic filter 100 is not separated from the R, S, and T phases, that is, whether or not the image harmonic separation condition is applicable. You can judge.

Hereinafter, an image harmonic filter control method according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1 and 2. 2 is a flowchart of a method of controlling an image harmonic filter according to an exemplary embodiment of the present invention. The description of the foregoing is omitted or simplified. By the following description, the configuration of the image harmonic filter control device can be more clearly described.

First, it may be determined whether the separation condition determiner 1200 corresponds to the separation condition (S21). The current on the image harmonic filter detected from the current detector 1400 may be used to determine the separation condition. Alternatively, the voltage on the image harmonic filter 100 may be used. The matters for which the separation condition determiner 1200 determines the separation condition of the image harmonic filter 100 are as described above. For example, the separation condition determiner 1200 may detect a current on at least one lead wound around the zigzag connection transformer through the current detector 1400 (S21a). In addition, the separation condition determiner 1200 may determine whether the harmonic component of the detected current falls within a preset range (S21b). That is, the separation condition determiner 1200 may determine whether the separation condition is applicable based on the harmonics of the current in the image harmonic filter. Unlike the above, the separation condition determiner 1200 may determine whether the separation condition is applicable based on a preset period.

If it is determined in S21 that it does not correspond to the separation condition, the separation condition determiner 1200 may repeat S21 according to a preset period.

If it is determined in S21 that the separation condition corresponds, the separation condition determination unit 1200 may electrically separate the image harmonic filter 100 from the R, S, and T phases by turning off the switching unit 1100 ( S22).

In addition, the imaging determination unit 1300 may determine whether the imaging is performed using voltages on the R, S, and T phases while the image harmonic filter 100 is electrically separated from the R, S, and T phases (S23). ). When the imaging determination unit 1300 completes the imaging determination or when the detection of the voltage used to make the imaging determination is completed, the image harmonic filter 100 may be connected to the R, S, and T phases again. In this case, when it is determined that the imaging determination unit 1300 is an imaging, the image harmonic filter 100 may not be connected to the R, S, and T phases again. As a result, in the case of power-side phase imaging, an abnormal voltage may not be supplied to the load by the image harmonic filter.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

100: video harmonic filter
1000: video harmonic filter control device
1100: opening and closing part
1200: separation condition determination unit
1300: imaging determination unit 1400: current detection unit

Claims (4)

It is determined whether or not the separation condition of the image harmonic filter connected to the R, S, T, N phase, and if it is determined to correspond to the separation condition, the image harmonic filter is electrically separated from the R, S and T phase, and A separation condition determination unit configured to control an image determination unit to diagnose whether or not an image side harmonic filter is electrically separated from the R, S, and T phases; And
And an opening / closing unit which is turned off in response to the separation condition determining unit determining that the separation condition corresponds to the separation condition. The method of claim 1,
The separation condition determination unit detects a current on at least one conductor wound around the image harmonic filter connected to the R, S, T, and N phases, and determines whether a harmonic component of the detected current corresponds to a preset value. And a harmonic component of the detected current corresponds to a predetermined value, and determines that the separation condition corresponds to the separation condition. The method of claim 1,
The image determination unit may determine whether an image is formed by using a voltage of at least one of the R, S, and T phases in which the image harmonic filter is electrically separated from the R, S, and T phases. Harmonic filter control device. Determining whether a separation condition of an image harmonic filter connected to R, S, T, and N is applicable;
In a step of determining whether the separation condition is applicable, electrically separating the image harmonic filter from the R, S, and T phases when it is determined that the separation condition corresponds; And
And diagnosing whether there is a power-side phase loss in the state in which the image harmonic filter is electrically separated from the R, S, and T phases.

Images