KR101030049B1 - The outdoor high voltage mold-type voltage transformer with partial discharge detection sensor - Google Patents

Abstract

The present invention relates to a high voltage outdoor epoxy resin molded instrument transformer having a PD (Partial discharging detection sensor), more specifically for the voltage detection inside the instrument transformer installed in the distribution line outdoors Built-in device detects partial discharge generated between high voltage charging part and earth or interface between primary conductor and epoxy resin in advance, and grasps operation status and replacement time of instrument transformer to supply reliable power smoothly, The purpose is to provide a high voltage outdoor epoxy resin molded instrument transformer with a partial discharge detection sensor that plays an important role in safety management during maintenance and inspection.

Partial discharge, detection, instrument transformer, outdoor epoxy, sensor

Description

High Voltage Outdoor Epoxy Resin Molded Instrument Transformer with Sensor for Partial Discharge Detection {THE OUTDOOR HIGH VOLTAGE MOLD-TYPE VOLTAGE TRANSFORMER WITH PARTIAL DISCHARGE DETECTION SENSOR}

The present invention relates to a high voltage outdoor epoxy resin mold type instrument transformer having a partial discharging detection sensor.

In general, the power system is installed in the power system that supplies the high voltage power to the facility in a wide range of power consumers, and is used for power measurement, control and protection, and it is used for epoxy mold type current transformer (CT) and instrument transformer (PT). : Epoxy mold type current transformer has internal installation equipment such as Potential Transformer, MOF, Bushing Device, Load Braker Switch (LBS), Vacuum Circuit Braker (VCB), etc. In order to reduce the high voltage of high voltage circuit to low voltage, it is used to connect between the three-phase and single-phase circuits, and it is used for voltmeter or power supply of switchboard.

Epoxy-mold instrument transformers are limited to indoors and have been used for outdoor use, but they have been gradually increasing in recent years. In addition, long-term use of molded products using epoxy resins causes local discharge to grow due to local high electric field concentration at the interface between electrodes and insulators due to mechanical, thermal, electrical and environmental degradation, resulting in partial discharge. There was a problem that the breakdown accident occurred.

In order to solve the above problems, in the present invention, by providing a flame-retardant FV-0 grade to the outdoor epoxy resin to protect it from the risk of fire and exhibit the characteristics of ultraviolet or UV (UV) stability while showing the equivalent properties of mechanical and physical properties compared to the used epoxy. Partial discharging (PD) sensor using FV-0 grade eco-friendly epoxy resin with excellent flame retardancy and excellent characteristics against heat shock and water repellent function to prevent water from penetrating easily. To provide a high voltage outdoor epoxy resin molded instrument transformer with a built-in detection sensor.

Another purpose is to integrate PD detection sensor into instrument transformer made of flame-retardant FV-0 grade outdoor epoxy resin, so that partial discharge (PD) generated between high voltage part primary winding and insulator inside instrument transformer Partial discharging detection sensor that detects faults and predicts failures in advance and prevents and monitors preventive diagnosis to ensure reliability and stability of power supply and to easily perform post-management such as maintenance and repair. To provide a high voltage outdoor epoxy resin molded instrument transformer with a built-in).

In order to achieve the above object, a high voltage outdoor epoxy resin mold type instrument transformer having a partial discharge detection sensor according to the present invention is provided.

It consists of instrument transformer installed in the high voltage switchgear,

The instrument transformer is formed of a cylindrical main body and a primary terminal for input and output (K, L) connection protrudes to one side of the upper end of the main body, and inside the primary terminal for input and output (K, L) connection. The primary winding is connected in a donut shape, and an annular core is formed in the instrument transformer in an annular shape through the center between the donut shaped primary windings. A partial discharge detection sensor and a drain coil are formed at one side of the primary winding. This is achieved by connecting them side by side and forming a drain coil connected to a PNC connector located at the bottom of the body.

As described above, the conventional epoxy mold instrument transformer is used alone and does not have reliability for the insulation accident of the instrument transformer during use, and as a result, the present invention provides a reliable power supply. It is an economical device integrating two functions with a sensor function to detect partial discharge as an instrument transformer by embedding a partial discharge detection sensor using a highly reliable outdoor epoxy resin. It is more reliable than the non-contact partial discharge detection method used, so it can be monitored during normal operation, which is convenient for stable power supply and safety management during maintenance and inspection.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a perspective view of a high-voltage outdoor epoxy resin molded instrument transformer with a built-in partial discharge detection sensor, which is a cylindrical main body and the primary terminal for input and output (K, L) connection to one side of the upper end of the main body The primary winding is connected in a donut shape inside the primary terminals for input and output (K, L) connection, and penetrates the center between the donut-shaped primary windings in an annular shape inside the instrument transformer. An annular core to be installed is formed, and the partial discharge detection sensor and the drain coil are connected to one side of the primary winding side by side, and the drain coil is connected to the PNC connector located at the bottom of the main body.

The partial discharge detection sensor (3) is made of epoxy resin and has a capacitance of 100 pF or more using a ceramic element having excellent insulation and temperature characteristics to detect a predetermined frequency band of partial discharge generated during operation of a transformer for instrument. Capacitive coupler is attached to high voltage side of instrument transformer and it has a frequency band of 10MHz ~ 50MHz (-5dB / cut-off) and is configured to measure partial discharge on-line.

The partial discharge detection sensor 3 is formed of a plurality of cylindrical ceramic dielectric bodies 16 having the same size, and a circular electrode 15 having a symmetrical shape on the high voltage side and the ground side is formed at both ends thereof. do.

Each ceramic dielectric body 16 has a unitary structure in which an adhesive is applied to a surface and bonded.

The partial discharge detection sensor 3 is an integrated body made of several bodies in one body, and the circular electrodes 15 are joined to both ends of the integrated body at both ends thereof. Both ends of the electrode are connected between the high voltage side primary winding inside the instrument transformer and the drain core 17 for blocking the commercial frequency.

The outdoor epoxy resin used as the molding material of the partial discharge detection sensor-type outdoor instrument transformer has the characteristics of flame retardant FV-0, so it has excellent self-extinguishing ability in the event of fire, outdoor water repellency, high mechanical strength, ultraviolet safety and corona resistance. The discharge characteristics are very good.

The main body is based on 15 to 35 parts by weight of a mixture (A) consisting of 40 to 60% by weight of epoxy resin (a) and 60 to 40% by weight of a curing agent (b), and 100 parts by weight of a mixture of 65 to 85 parts by weight of filler (B). It is produced by reacting and curing for 30 minutes to 48 hours at 30 to 90 ° C while mixing 0.1 to 5.0 parts by weight of the curing accelerator (C).

 Moreover, after making the said raw material react and mixing, it can also make it react, after raising completely at room temperature.

 The characteristic difference from the conventional technology is that the conventional molding composition is a two-component type, while in the present invention, the content of the filler is increased and a part of the epoxy resin is not reacted to solid-liquid separation, and the solid or semi-solid at room temperature can be molded at high pressure. It was Newtonian flow.

 Epoxy resin (a) uses a low viscosity cycloaliphatic epoxy resin designed to be molded by a conventional casting method or APG method (automatic pressure gelation method).

 By cyclo aliphatic structure is meant the absence or minimization of an aromatic structure in a molecule. The presence of an aromatic structure combines with oxygen or easily decomposes by ultraviolet light, resulting in poor weather resistance.

 Epoxy resins having a cyclo aliphatic structure include glycidyl ester epoxy resins, cyclic aliphatic epoxy resins, heterocyclic epoxy resins, and hydantin type epoxy resins.

As glycidyl ester epoxy resin, diglycidyl hexahydrophthalate, diglycidyl tetrahydrophthalate or a mixture thereof is used.

As the cyclic aliphatic epoxy resin, an alicyclic diepoxycetal, an alicyclic diepoxydiate, an alicyclic diepoxycarboxylate or a mixture thereof is used. As the heterocyclic epoxy resin, triglycidyl isocyanate is used. .

As the curing agent (b), methyl hexahydrophthalic acid, hexahydrophthalic acid or a derivative thereof is used. The use of aliphatic acid anhydride together increases the thermal shock resistance.

As the filler (B), silica powder is used. Using aluminum hydroxide together increases cracking resistance and flame retardancy.

In addition, the filler (B) is preferably subjected to a silane treatment before use. The silane treatment increases the adhesion to the epoxy resin.

In addition, the filler (B) is preferably dried sufficiently before use.

The curing accelerator (C) is selected from tertiary amines, Lewis acids, organometallic compounds, and organic acid metal salts.

In addition, functional additives such as silicone oils or derivatives thereof, as well as pigments, antioxidants, ultraviolet absorbers, flame retardants, thickeners, mold release agents, glass fibers, thixotropy-imparting agents and the like may be added according to required properties.

The semi-hardening process is made by making it react for 30 to 120 minutes at 60-90 degreeC, mixing using an ultrahigh viscosity mixer. The semi-hardening process may be carried out by mixing the raw materials in a mixer, or by mixing the raw materials and then raising the temperature to react.

It is preferable to carry out vacuum defoaming during the reaction. By semi-curing, solid-liquid separation does not occur during molding (extrusion molding, injection molding), and has viscosity corresponding to the molding pressure.

The configuration of the present invention will become more apparent from the examples and comparative examples to be described later.

Example 1

(A) Raw material mixture (filler content: 75% by weight)

13% by weight of epoxy resin diglycidyl hexahydrophthalate

(b) 11 wt% of hardener hexahydrophthalic acid

(B) 75% by weight of filler silica

(C) 0.5% by weight of curing accelerator benzyldimethylamine

(D) 0.5% by weight of other additives silicone oil

 (B) Manufacturing method

The compounds were reacted at 80 ° C. for 90 minutes while mixing with a high viscosity mixer, followed by vacuum extrusion with an extruder to form a solid molding material at room temperature (25 ° C.).

After forming the specimen by extrusion molding at a pressure of 100Kg _f / ㎠ at 140 ℃ as a molding material, the strength, electrical properties and the like were measured.

(Example 2)

 (A) Raw material mixture (filler content: 80% by weight)

(a) 8% by weight of epoxy resin diglycidyl hexahydrophthalate

   Ali cyclic diepoxycetal 2% by weight

(b) 8.5 wt% of a curing agent methylhexahydrophthalic acid

(B) 80% by weight of filler silica

(C) curing accelerator sodium alcohol 0.5% by weight

(D) 0.5% by weight of water repellent epoxy modified silicone oil

 Release agent zinc stearate 0.5% by weight

Cylindrical instrument transformer according to the present invention made of such epoxy resin has the characteristics of flame-retardant FV-0, has excellent self-extinguishing ability in the case of fire, and has excellent outdoor water repellency, high mechanical strength, UV safety and corona discharge characteristics. great.

1 is a perspective view of a high voltage outdoor epoxy resin molded instrument instrument with a partial discharge detection sensor;

2 is a cross-sectional view of a high-voltage outdoor epoxy resin molded instrument transformer with a partial discharge detection sensor;

3 is an exploded perspective view showing components of a partial discharge detection sensor;

※ Brief description of drawing code ※

3: Partial discharge detection sensor 11: Primary terminal (K.L)

12: primary winding 13: secondary winding

14: iron core core 15: electrode conductor (upper, lower)

16 ceramic dielectric body 17 high frequency blocking core

18: PNC connector 19: Ground terminal

Claims (4)

In the instrument transformer installed in the high voltage switchgear, The instrument transformer is formed of a cylindrical main body and a primary terminal for input and output (K, L) connection protrudes to one side of the upper end of the main body, and inside the primary terminal for input and output (K, L) connection. The primary winding is connected in a donut shape, and an annular core is formed in the instrument transformer in an annular shape through the center between the donut shaped primary windings. A partial discharge detection sensor and a drain coil are formed at one side of the primary winding. The high voltage outdoor epoxy resin molded instrument transformer with a partial discharge detection sensor, which is connected side by side and a drain coil is connected to a PNC connector located at the bottom of the main body. The partial discharge detection sensor according to claim 1, wherein the partial discharge detection sensor is integrally formed by joining a plurality of cylindrical ceramic dielectrics between a high voltage side and a ground side, and a circular electrode symmetrical is formed on the upper and lower sides. High voltage outdoor epoxy resin molded instrument transformer. The main body is 15 to 35 parts by weight of the mixture (A) consisting of 40 to 60% by weight of the epoxy resin (a) and 60 to 40% by weight of the curing agent (b), and 65 to 85 parts by weight of the filler (B). Based on 100 parts by weight of the mixture, curing accelerator (C) 0.1 to 5.0 parts by weight while mixing at 30-90 ° C. for 30 minutes to 48 hours to produce a semi-discharge detection sensor with a built-in sensor for partial discharge, characterized in that Epoxy Resin Molded Instrument Transformer. The high-voltage outdoor epoxy with a built-in partial discharge detection sensor according to claim 2, wherein the ceramic dielectric is formed by connecting a wound drain core for high frequency blocking and commercial frequency bypass between the lower electrode and the ground. Resin Molded Instrument Transformer.

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