KR102221399B1 - PD measuring device with multi-measurement input conversion - Google Patents

Abstract

The present invention relates to a partial discharge (PD) measuring device, and more particularly, to a PD measuring device capable of increasing the resolution of internal PD and external PD by using a plurality of PD sensors. According to one preferred embodiment of the present invention, the PD measuring device through multi-measurement input conversion comprises: a group conversion unit synthesizing the output of a plurality of CTs installed in a diagnosis target area; and a measurement and determination unit determining whether the PD has occurred and a location of PD occurrence using the output of the group conversion unit.

Description

PD measuring device with multi-measurement input conversion}

The present invention relates to a PD measurement apparatus, and more particularly, a PD measurement apparatus capable of increasing resolution for an internal PD (Partial Discharge, partial discharge, hereinafter referred to as'PD') and an external PD using a plurality of PD sensors. It is about.

A device that quantitatively measures the amount of PD discharge employs a method in which the PD sensor and the measuring unit measure one-to-one, or N sensors are connected to one measuring unit with a time difference through switching to measure each other. Here, the switching method is a method of measuring by connecting only one sensor to one measuring device. The method of diagnosing PD by analyzing the waveform is also expensive, but the same method as above is applied.

Since the method of quantitatively measuring the PD value only measures the amount of discharge flowing into the sensor, it is difficult to check whether PD occurs in the section to be diagnosed or inside the product. In addition, since the PD diagnosis method for analyzing waveforms is expensive, it is used as a portable type, and it is difficult to apply it for field measurement.

1. Application No.: 10-1995-0026898 (Name of invention: Partial discharge measurement method using a frequency spectrum analyzer) 2. Application No.: 10-2001-0043513 (Name of invention: High sensitivity time domain, frequency domain automatic selection type partial discharge measurement system)

An object of the present invention is to provide a PD measurement device through conversion of a multi-measurement input unit capable of accurately determining whether a PD occurs in a section to be diagnosed or inside a product at a low cost.

According to a preferred embodiment of the present invention, a PD measurement apparatus through conversion of a multi-measurement input unit includes: a group conversion unit for synthesizing outputs of a plurality of CTs installed in a diagnosis target area; And a measurement and determination unit for determining whether a PD occurs and a location of the PD using the output of the group conversion unit.

Here, the plurality of CTs may be installed such that outputs of the plurality of CTs synthesized by the group conversion unit are scaled up or scaled down when a PD occurs inside a diagnosis target area.

In addition, when the plurality of CTs are installed to be scaled-up when the output of the plurality of CTs synthesized by the group conversion unit is a PD occurs inside the diagnosis target area, the measurement and determination unit is a group conversion unit including polarity. If the output exceeds the PD reference value, it can be determined that PD has occurred in the area to be diagnosed.

In addition, the diagnosis target area is plural, and a group conversion unit is installed to match each of the diagnosis target areas, and a selection unit is installed so that the measurement and determination unit selects any one of a plurality of group conversion units to diagnose the PD. I can.

In addition, the diagnosis target area may be any one of each phase of the ground switch and power equipment.

In the present invention, it is possible to accurately determine whether PD occurs and the location of the PD using a plurality of CTs installed in the area to be diagnosed.

1 is a functional block diagram of a PD measurement device according to an exemplary embodiment of the present invention.
2 shows an example in which the present invention is applied to a ground switch.
3 is a diagram for explaining the polarity of the CT.
4 shows another embodiment of FIG. 2.
5 shows an example in which the present invention is applied to a power device.
6 shows another embodiment of FIG. 5.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

Accordingly, the present invention may be subjected to various changes and may have various embodiments, and it should be understood that all changes, equivalents, and substitutes included in the spirit and scope of the present invention are included.

On the other hand, in describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Terms such as first and second may be used to describe various elements, but the elements are not limited by the terms. These terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

The term and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

The terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present invention, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance the possibility of being added.

Unless otherwise defined, all terms including technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present invention. Does not.

The terms or words used in this specification and claims are not to be construed as limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

Hereinafter, a PD measurement apparatus through conversion of a multi-measurement input unit according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1 to 6. In order to clarify the gist of the present invention, a description of conventionally well-known matters will be omitted or simplified.

Referring to FIG. 1, the PD measurement device includes a plurality of CTs (Current Transformer), a group conversion unit 10, a selection unit 20, a selection control unit 30, a measurement and determination unit 40, and an information transmission unit 50. , It may include a power supply (60).

The plurality of CTs may be High Frequency Current Transformers (HFCTs). A plurality of CTs may be installed in each of the at least one diagnosis target area (1, ..., N).

A plurality of CTs (1-1, ..., 1-M) may be installed in the first diagnosis target area (1). A plurality of CTs (N-1, ..., N-M) may be installed in the Nth diagnosis target area (N). Here, N and M may be an integer of 2 or more.

At least one of the group conversion units 10-1 and 10-N may be matched to each diagnosis target area. The group conversion units 10-1 and 10-N may synthesize output signals of a plurality of CTs installed in the diagnosis subject area for each diagnosis subject area and output to the selection unit 20. At this time, the group conversion units 10-1 and 10-N may synthesize the output signals of the plurality of CTs in either an analog method or a digital method. A plurality of CTs installed in the diagnosis subject area may be installed such that the output of the CT synthesized by the group conversion unit is scaled up when PD occurs inside the diagnosis subject area and scaled down when PD occurs outside the diagnosis subject area. Conversely, multiple CTs installed in the diagnosis target area can be installed so that the output of the CT synthesized by the group conversion unit scales down when PD occurs inside the diagnosis target area, and scales up when PD occurs outside the diagnosis target area. have.

The selection unit 20 includes a plurality of group conversion units and a measurement and determination unit 40 so that the measurement and determination unit 40 outputs a signal of only one diagnosis target area to measure the PD to the measurement and determination unit 40. ) To perform a switching (in other words, selection) operation. To this end, the selection unit 20 may include a switch provided between each of the plurality of group conversion units 10-1, ..., 10-N and the determination unit 40.

The selection control unit 30 receives a selection command for the area to be diagnosed from the measurement and determination unit 40, and according to the selection command, the selection unit 20 allows the selection unit 20 to select any one of a plurality of group conversion units. ) Can be controlled. Here, the selection command may include the diagnosis target area identifier. The selection control unit 30 may control an on/off operation of a switch provided in the selection unit 20 so that the group conversion unit matched to the diagnosis target area identified in the selection command and the measurement and determination unit 40 are connected. .

The measurement and determination unit 40 may determine whether the PD occurs and the location of the PD using the output signals of each of the plurality of group conversion units 10-1, ..., 10-N. In this case, the measurement and determination unit 40 may compare the output value of the group conversion unit with the PD reference value to determine whether the PD is authentic (whether PD has occurred). When determining whether the PD is authentic, the absolute value of the output of the group conversion unit may be used. The measurement and determination unit 40 may determine that PD has occurred when the output of the group conversion unit exceeds the PD reference value. In addition, when it is determined that the PD has occurred, the measurement and determination unit 40 may determine the location of the PD occurrence. In this case, the measurement and determination unit 40 may determine that the PD has occurred inside or outside when the output value of the group conversion unit falls within a preset range compared to the position reference value. For example, if multiple CTs installed in the diagnosis target area are installed to be scaled up when the output of the CT synthesized by the group conversion unit is a PD generated inside the diagnosis target area, the diagnosis target if the output value of the group conversion unit is greater than the position reference value. It is determined that PD has occurred inside the area, and if the output value of the group conversion unit is less than the position reference value, it can be determined that the PD has occurred outside the area to be diagnosed. Conversely, if multiple CTs installed in the diagnosis target area are installed so that the output of the CT synthesized by the group conversion unit is scaled down when PD occurs inside the diagnosis target area, the output value of the group conversion unit is less than the position reference value, the diagnosis target area If it is determined that PD has occurred inside and the location reference value is exceeded, it can be determined that PD has occurred outside the area to be diagnosed.

Unlike the above, the output of the CT synthesized by the group conversion unit of a plurality of CTs installed in the diagnosis subject area is installed to be scaled up when PD occurs inside the diagnosis subject area, and the measurement and determination unit 40 includes polarity. If the output of the group conversion unit exceeds the PD reference value, it may be designed to determine that PD has occurred in the area to be diagnosed. In this case, the process of the measurement and determination unit 40 for determining the authenticity of the PD and the location of the occurrence of the PD can be simplified and manufactured at low cost. Accordingly, it may be desirable to install a plurality of CTs installed in the diagnosis target area to be scaled-up when the output of the plurality of CTs synthesized by the group conversion unit is a PD occurs inside the diagnosis target area.

On the contrary, the output of the CT synthesized by the group conversion unit of a plurality of CTs installed in the diagnosis target area is scaled down when PD occurs inside the diagnosis target area, and scaled up when PD occurs outside the diagnosis target area. The measurement and determination unit 40 may be designed to determine that PD has occurred outside the diagnosis target area when the output of the polarity included group conversion unit exceeds the PD reference value. However, if the CT is installed in this way, if a PD occurs inside the diagnosis target area, the PD inside the diagnosis target area may not be properly recognized due to the output of the group conversion unit that is scaled down.

The information transmission unit 50 may inform the outside of the determination result of the measurement and determination unit 40. In this case, the display unit (not shown) may be displayed to the outside, an alarm unit may be provided to the outside through an alarm unit (not shown), or whether or not the PD has occurred and the location of the PD may be remotely informed through the communication unit 50.

The power supply unit 60 may supply power required for operation of the PD measuring device.

Referring to FIG. 2, CTs 1-1, 1-2, and 1-3 may be installed on the in/out cable on the ground switch A. 2 illustrates a case of a three-circuit type ground switch. In FIG. 2, the A phase at the far left may be the main (Main, power stage), and the other A phase may be the sub (Sub, branch).

Referring to FIG. 3, the polarity of the CT (1-1) may be indicated by dots. In Fig. 3, a dot is displayed on the lower side of the CT (1-1). In this case, when the PD occurs under the CT (1-1), a + voltage is induced at the lower terminal of the CT (1-1). On the contrary, when it occurs above the CT (1-1), a-voltage is induced at the upper terminal of the CT (1-1). Using the fact that the location where the PD occurs is correlated with the polarity of the voltage of the CT, the present invention determines whether the PD has occurred using a plurality of CTs and whether the PD has occurred inside or outside the diagnosis target area. Can be judged.

Again, referring to FIG. 2, a plurality of CTs (1-1, 1-2, 1-3) installed on the three A-phase cables are all marked with dots on the upper side (the ground switch side). In this case, when the PD occurs on A in the ground switch, the outputs of the plurality of CTs 1-1, 1-2, and 1-3 synthesized by the group conversion unit 20 may be scaled up. On the contrary, when PD occurs outside the ground switch (the lower side of the plurality of CTs or the opposite side of the ground switch in each of the plurality of CTs), the output of the plurality of CTs (1-1, 1-2, 1-3) is It can be scaled down. In the same manner as in FIG. 2, CT is installed in each of the B phase and C phase, and the PD can be diagnosed in the same manner. At this time, when a CT is installed in each of the phases A, B, and C, each phase is a diagnosis target area, and the measurement and determination unit may use the output of each diagnosis target area to classify the image in which PD occurs.

Referring to FIG. 4, a plurality of CTs (1-1, 1-2, 1-3) installed on three phase A cables are all marked with dots at the bottom (the opposite side of the ground switch). In this case, when the PD occurs on the A phase inside the ground switch, the output of the plurality of CTs (1-1, 1-2, 1-3) synthesized by the group conversion unit 20 is scaled down (when considering polarity) ) Can be. However, it may be scaled up in the concept of absolute values of outputs of the plurality of CTs 1-1, 1-2, and 1-3 synthesized by the group transform unit 20. Conversely, when PD occurs outside the ground switch (the lower side of the plurality of CTs or the opposite side of the ground switch in the plurality of CTs), the output of the plurality of CTs (1-1, 1-2, 1-3) is scaled. It can be down (in absolute value concept).

5, the power device 1 is installed on the power line L, and the CTs 1-1 and 1 on the primary side (or input side) and the secondary side (or output side) of the power device 1, respectively. 1-2) can be installed. In FIG. 5, the power device may mean a diagnosis target area. Power equipment may be PT, MOF, ACB, etc.

In Fig. 5, the CT (1-1) installed on the power device input side has a dot on the bottom (the power device side), and the CT (1-2) installed on the power device output side has a dot on the top (power device side). Has been. In this case, when the PD occurs inside the power device, the outputs of the plurality of CTs 1-1 and 1-2 synthesized by the group conversion unit 20 may be scaled up. Conversely, when the PD occurs outside the power device (the opposite side of the power device in each of the plurality of CTs), the output may be scaled down.

Referring to FIG. 6, the power device 1 is installed on the power line L, and the CTs 1-1 and 1 on the primary side (or input side) and the secondary side (or output side) of the power device 1, respectively. 1-2) can be installed. In FIG. 6, the power device may mean a diagnosis target area. Power equipment may be PT, MOF, ACB, etc.

In Fig. 6, the CT (1-1) installed on the power device input side has a dot on the top (the power device side), and the CT (1-2) installed on the power device output side has a dot on the top (power device side). Has been. In this case, when the PD occurs inside the power device, the outputs of the plurality of CTs 1-1 and 1-2 synthesized by the group conversion unit 20 may be scaled down. Conversely, when the PD occurs outside the power device (the opposite side of the power device in each of the plurality of CTs), the output can be scaled up.

As described above, according to the present invention, it is possible to accurately determine whether a PD occurs and a location of the PD using a plurality of CTs installed in a diagnosis target area. In addition, when a plurality of CTs have a PD in a diagnosis target area, by installing a plurality of CTs so that the outputs of the plurality of CTs are scaled up, it is possible to accurately determine whether a PD occurs in the diagnosis target area.

When there is only one area to be diagnosed, unlike FIG. 1, the selection unit 20 and the selection control unit 30 are omitted, and the function related to selection of the diagnosis target area or group conversion unit of the measurement and determination unit 40 may be omitted. have. In this case, the measurement and determination unit can accurately determine whether PD occurs in the diagnosis subject area using the output of a single group conversion unit that combines the outputs of a plurality of CTs installed in a single diagnosis subject area.

The present invention can be applied to each phase of a power device including a plurality of circuits as described above and all power devices installed on a power line as a diagnosis target area.

In addition, CTs are installed on both sides to monitor a certain section of the power line, and by synthesizing the CT signals in the section, it is possible to determine whether a PD has occurred in the section.

That is, in the present invention, the diagnosis target area may be a concept including all of a specific power device, a device inside a specific power device, and a specific section in the power network.

1, N: area to be diagnosed
1-1, 1-M, N-1, NM: CT
10-1, 10-N: group conversion unit
20: selection
30: selection control
40: measurement and judgment unit
50: information transmission unit
60: power supply

Claims (5)

A group conversion unit for synthesizing outputs of a plurality of CTs installed in the first diagnosis target area; And
A measurement and determination unit for determining whether PD occurs and a location of PD using the output of the group conversion unit,
The plurality of CTs are installed such that outputs of the plurality of CTs synthesized by the group conversion unit are scaled up when a PD occurs inside the first diagnosis target area,
When the absolute value of the output value of the group conversion unit exceeds the PD reference value, the measurement and determination unit determines that PD has occurred,
When it is determined that PD has occurred, the measurement and determination unit determines the location of the PD occurrence,
When the measurement and determination unit determines the PD generation location, if the output value of the group conversion unit is greater than or equal to the position reference value, it is determined that PD has occurred inside the first diagnosis target area, and when the output value of the group conversion unit is less than the position reference value, the first It is determined that PD has occurred outside the area to be diagnosed,
The plurality of CTs are PD measurement apparatus through conversion of a multi-measurement input unit, characterized in that the dots are installed on the side of the first diagnosis target area. delete delete The method of claim 1,
The first diagnosis target area is plural,
A group conversion unit is installed to match each of the plurality of first diagnosis target areas,
PD measurement device through a multi-measurement input unit conversion, characterized in that the selection unit is installed so that the measurement and determination unit selects any one of a plurality of group conversion units to diagnose the PD. The method of claim 1,
The first diagnosis target area is a PD measurement apparatus through conversion of a multi-measurement input unit, characterized in that any one of each phase of a ground switch and a power device.

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