KR100787964B1 - Out-door type metering out-fit (mof)having electronics transformer with auxiliary power supply device & pd detection sensor - Google Patents

Abstract

An outdoor type MOF(Metering Out-Fit) having an electronic transformer with an auxiliary power supply device and a PD(Partial Discharge) detection sensor is provided to reduce an installation space by integrally embedding the auxiliary power supply device in the MOF. An auxiliary power supply device has an auxiliary power supply capacitor and a power supply transformer, and is formed at one side of an EVT(Electronic Voltage Transformer). The auxiliary power supply capacitor has a main capacitor and a voltage dividing capacitor parallel connected between a high voltage side conductor(12) for input/output connection and a ground. A PD(Partial Discharge) detection sensor is formed at the opposite side of the auxiliary power supply capacitor on the basis of an ECT(Electronic Current Transformer), and is parallel connected between the high voltage side conductor and a secondary output ground terminal.

Description

OUTDOOR TYPE METERING OUT-FIT (MOF) HAVING ELECTRONICS TRANSFORMER WITH AUXILIARY POWER SUPPLY DEVICE & PD DETECTION SENSOR}

1 is a front view showing a high voltage outdoor electronic MOF having a built-in auxiliary power supply and a partial discharge detection sensor in an electronic transformer (ECT / EVT) according to the present invention;

2 is a front view showing a high-voltage three-phase outdoor electronic MOF having an auxiliary power supply and a partial discharge detection sensor in an electronic transformer (ECT / EVT) according to the present invention;

3 is a plan view showing a high-voltage three-phase outdoor electronic MOF having a built-in auxiliary power supply and a partial discharge detection sensor in an electronic transformer (ECT / EVT) according to the present invention;

Figure 4 is an embodiment showing the internal configuration of a high-voltage outdoor electronic MOF having a built-in auxiliary power supply and a partial discharge detection sensor in the electronic transformer (ECT / EVT) according to the present invention,

Figure 5 is an embodiment showing the internal configuration of a high-voltage outdoor electronic MOF having a built-in auxiliary power supply and a partial discharge detection sensor in the electronic transformer (ECT / EVT) according to the present invention.

Figure 6 is an embodiment showing the configuration of the ECT of the components of the high-voltage outdoor electronic MOF having a built-in auxiliary power supply and a partial discharge detection sensor in the electronic transformer (ECT / EVT) according to the present invention,

7 is an integrator circuit diagram added to the ECT of the components of the high-voltage outdoor electronic MOF having a built-in auxiliary power supply and a partial discharge detection sensor in the electronic transformer (ECT / EVT) according to the present invention;

FIG. 8 is a diagram illustrating a partial voltage dividing method of an EVT among components of a high voltage outdoor electronic MOF having an auxiliary power supply and a partial discharge detection sensor embedded in an electronic transformer (ECT / EVT) according to the present invention;

9 is a semi-circular mesh-type metal screen shield attached to the upper and lower parts of the EVT of the high voltage outdoor electronic MOF having a built-in auxiliary power supply device and a partial discharge detection sensor in the electronic transformer (ECT / EVT) according to the present invention. Screen shield)

Figure 10 is formed of a semi-conductive functional synthetic resin attached to the upper and lower end of the EVT component of the high-voltage outdoor electronic MOF having a built-in auxiliary power supply and partial discharge detection sensor in the electronic transformer (ECT / EVT) according to the present invention Perspective view of semicircular shield

Description of the main symbols in the drawings

11: BASE

12: High voltage side conductor for K, L connection 13: Grounding terminal

14: 2nd output ground terminal box 15: BASE ground terminal

16: Electronic current transformer (ECT)

17: Electronic voltage transformer (EVT)

18: auxiliary power supply capacitor

19: power supply Transformer 20: power supply

21: PD detection sensor 22: EPOXY (epoxy resin)

The present invention relates to a high voltage outdoor electronic MOF incorporating an auxiliary power supply and a partial discharge (PD) detection sensor in an electronic transformer ECT / EVT.

An electronic transformer (ECT / EVT) has two meanings: the electronic circuitry is provided in the transformer itself and suitable for microprocessor applications. In other words, Rogowski coil without electronic circuit can be classified as electronic transformer because it is suitable for microprocessor application without electronic circuit. In short, all existing transformers and relative transformers can be collectively referred to. The terms Electronic voltage transformer (EVT) and Electronic current transformer (ECT) are used.

The electronic transformer is a concept relative to the existing induction transformer. The main difference between the inductive type transformer and the electronic transformer is the burden and the output signal size.

The output of the inductive current transformer is usually 5 [A] or 1 [A], the load is about 15 [VA], and the output voltage of the inductive voltage transformer is generally 110 [V] and 220 [V]. Is about 100 [VA].

In contrast, the output of the electronic current transformer is a voltage different from the inductive type, and is typically 22.5 mV, 150 mV, 200 mV, 225 mV, and 4 V. The burden is expressed in units of high resistance [MΩ] rather than VA. The output of the electronic voltage transformer is also voltage but very low, typically 1.32V, 1.625V, 2V, 3.25V, 4V and 6V. In inductive, the burden means the capacity the transformer can output, but The same concept of resistance means the lowest impedance of the electronic device to be connected.

The outputs of electronic transformers are largely analog and digital. Analog does not use a special converter, in which case the output may be used as it is and some electronic circuits may be included. Data can be sent and received to the remote device. In order to use such a digital method, a communication circuit is constructed on the secondary side of the electronic transformer. In particular, when measuring power by configuring three phases, first, three phases are configured for each of the voltage and current transformers, and then IEC Using a merging unit or an IEEE intermediate device, a single signal source is used.

To summarize the characteristics of such an electronic transformer,

-No iron core and no iron resonance and saturation characteristics

(ECT: Use Rokoski Coil, EVT: Use R-divider, C-divider, RC-divider)

Secondary characteristics appear linear over a wide range of currents and voltages.

-Small size and light weight make it easy to reduce and install the size of switchboard.

High accuracy for secondary current and voltage

Direct connection to electronic instruments and relays is possible.

-One sensor can be used at the same time.

-Digitization of various equipments is possible.

-Compared to the traditional induction products, there is no direct damage even if the winding is wrong.

-High voltage is not induced even in the second opening and short-circuit, reducing the risk of electric shock.

In this regard, high-voltage outdoor MOF is an important power distribution facility that requires accurate and accurate metering and measurement of power supply and demand for customers, and reliability is required by insulation performance and failure prevention diagnosis. Although it is manufactured and used as an oil insulation method, there are limitations on precision, high output voltage and burden due to high voltage coil partial pressure, limit of securing insulation performance according to output signal, and environmental problems of oil insulation method.

Therefore, the outdoor electronic MOF requires low burden, high precision ECT, EVT design for precise and reliable power supply.In particular, in the case of EVT of high voltage resistance partial voltage type, the electric epoxy resin mold insulation type for the electric field concentrates the electric field on the high voltage resistance. In order to prevent this problem, the insulation breaks down between the high voltage resistance and the epoxy. Therefore, a shield should be installed at both ends of the main resistance to have an electric field smoothing structure to achieve electric field relaxation.

In addition, deterioration proceeds due to partial discharge (PD) occurring at the void and the live part conductor interface inside the epoxy resin mold, which may cause an insulation breakdown accident, so that a partial discharge (PD) detection sensor can be solved. It should be designed to ensure reliability and stability by detecting partial discharge (PD), predicting failure in advance, and performing preventive diagnosis monitoring.

In addition, the electronic electricity meter used with the electronic (ECT / EVT) MOF can be weighed only when other power is supplied. In the electronic MOF, the output of the EVT is very small, and thus it cannot be used as a power supply for the electricity meter.

In addition, in the case of supplying external power, it is impossible to meter the electricity meter due to the power failure.

In addition, the method of supplying external power must be supplied with a separate transformer or battery method. In this case, installation cost, installation space, and additional equipment are additionally required.

 Therefore, in order to solve this problem, an auxiliary power supply should be built in the electronic MOF to supply power without a separate power supply to accurately measure the amount of power, reduce the installation area, and be designed for easy maintenance. In addition, the electronic MOF of the present invention has a need to be designed based on the partial discharge reduction technology, environmentally friendly insulation method excellent in heat resistance, water repellency and flame retardancy.

In order to solve the above problems, the present invention provides a high-voltage outdoor epoxy resin molded electronic MOF (ECT / EVT) incorporating an auxiliary power supply and a partial discharge (PD) detection sensor in the electronic transformer (ECT / EVT). The purpose is.

In the present invention to achieve the above object,

The high voltage side conductor 12 for input and output (K, L) connection protrudes to one side of the upper surface, and passes through the center between the high voltage side conductor 12 for input and output (K, L) connection. ECT (Electronic Current Transformer) 16 is formed inside the annular shape, and the high-voltage side conductors 12 and 2 for input and output (K, L) connection on one side of the ECT (Electronic Current Transformer) 16. While connected to the vehicle output ground terminal box (14-1) is formed EVT (Electronic Voltage Transformer) 17 is installed in an I-shape,

The main capacitor 18-1 and the voltage dividing capacitor 18-2 are in parallel between the high voltage conductor 12 for input and output (K, L) connection and the ground on one side of the EVT 17. An auxiliary power supply device 20 including a connected auxiliary power supply capacitor 18 and a power supply transformer 19 is formed, and the auxiliary power supply capacitor 18 is based on the electronic current transformer (ECT) 16. Is achieved by forming a partial discharge detection sensor 21 which is installed while being connected in parallel between the high voltage side conductor 12 for input / output (K, L) connection and the secondary output terminal 14-2.

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

The high-voltage outdoor electronic MOF having an auxiliary power supply and partial discharge (PD) detection sensor in the electronic transformer (ECT / EVT) according to the present invention is an electronic current transformer (ECT) 16 and an electronic voltage transformer (EVT) 17. ), The partial discharge detection sensor 21, and the auxiliary power supply device 20.

The ECT (Electronic current transformer) 16 is a Rogowski-type electronic current transformer (CT) installed in the electronic MOF to detect the supply current of the consumer to accurately measure and measure the amount of power, which is nonmagnetic. Rogowski coil (RC) is wound around the core (μ = μ0), the integrator is added to have a function as an electronic current transformer (ECT).

That is, the electronic current transformer (ECT) 16 according to the present invention, as shown in FIG. 6, the RC formed around the power conductor 21 secures the insulating layer 22 and the non-magnetic core 23. The outer periphery is insulated with an insulating tape 24 and then wound by an enameled insulated coil 25, and the coil outer periphery is insulated with an insulating tape 26, and then semi-conductive tape 27. Logo ski coil (RC) formed by the shield (Shield) process or the like is configured.

In addition, the integrator circuit as shown in FIG. 7 is added and comprised.

Electronic current transformer (ECT) 16 according to the present invention having such a configuration is a high-voltage side conductor 12 for input and output (K, L) connection protruding to one side of the upper surface as shown in Figure 4 and 5 Is installed in an annular shape inside the electronic MOF through the center between, and is connected to the secondary output grounding terminal box 14 through the electrical wiring to one side of the lower end.

The electronic voltage transformer (EVT) 17 is an electronic voltage transformer (VT) of a resistive voltage divider installed in an electronic MOF to detect a supply voltage of a consumer and to accurately measure and measure the amount of power. As shown in the figure, the resistive voltage dividing method of the main resistor 17-2 and the voltage dividing resistor 17-3 connected in series is configured to have a function as an EVT.

Here, the resistance divided method of the main resistor 17-2 and the divided resistor 17-3 can be expressed by Equation (1).

An electronic voltage transformer (EVT) 17 according to the present invention having such a configuration is a high voltage conductor for input and output (K, L) connection to one side of an electronic current transformer (ECT) 16, as shown in FIG. (12) is connected between the secondary output ground terminal box (14-1) is installed in an I-shape.

Here, the secondary output ground terminal box 14 is composed of an output ground terminal 14-1 and an output terminal 14-2.

The electronic voltage transformer (EVT) 17 installed in this way has a semicircular mesh screen shield or semi-circular shield 17-1 formed of semi-conductive functional synthetic resin at the upper and lower ends thereof. The main resistor 17-2 is formed between the upper and lower shields, and the divided resistor 17-3 is formed in series with the main resistor 17-2 on one side of the shield of the lower end.

Here, the shield (17-1) is an electric field smoothing can be installed at both ends of the main resistance to prevent the problem caused by the electric field is concentrated on the main resistance and the insulation is broken by the electrical stress occurs. It is composed of a structure.

Shield 17-1 according to the present invention having such a configuration is formed as a semi-circular shield made of a semi-conductive functional synthetic resin as shown in FIG. 9, or as shown in FIG. It is formed of a mesh-type metal screen shield having a plurality of holes formed along the semicircular circumference.

The partial discharge detection sensor 21 deteriorates due to partial discharge (PD) occurring at the interface of the void and the live part of the conductor remaining inside the epoxy resin mold of the outdoor high voltage electronic MOF, which is caused by an insulation breakdown accident. In order to solve this problem, PD detection sensor is built in to solve this problem, so it detects PD and predicts failure in advance and secures reliability and stability by performing preventive diagnosis and monitoring. It is configured to be.

As shown in FIG. 4, the partial discharge detection sensor 21 has a high voltage side for connecting the input / output (K, L) to the opposite side of the auxiliary power supply capacitor 18 based on the ECT (Electronic Current Transformer) 16. It is molded with an epoxy resin while being connected in parallel between the conductor 12 and the secondary output terminal 14-2.

The auxiliary power supply device 20 is a main capacitor (18-1) and the voltage divider between the high-voltage conductor 12 for input and output (K, L) connection to one side of the EVT (Electronic Voltage Transformer) 17 and the ground The capacitor 18-2 is composed of an auxiliary power supply capacitor 18 and a power supply Transformer 19 connected in parallel.

In particular, the auxiliary power supply capacitor 18 according to the present invention is composed of a main capacitor 18-1 and a voltage dividing capacitor 18-2 using the capacitor partial pressure method to the voltage dividing capacitor 18-2. It serves to supply the necessary auxiliary power by a transformer (19) for power supply connected in parallel, which is, as shown in Figure 4, based on the ECT (16) PD detection sensor ( 21 is formed in a multi-stage cylindrical shape to be installed while being connected between the high-voltage conductor 12 for input and output (K, L) connection and the power supply transformer 19 on the opposite side.

As described above, the auxiliary power supply capacitor 18 according to the present invention is configured in a capacitor partial pressure method consisting of a main capacitor 18-1 and a voltage dividing capacitor 18-2, and the upper side of the main capacitor 18-1. It is connected to the high-voltage side conductor 12 for input / output (K, L) connection, and is connected to the input terminal of the power supply transformer 19 at one side of the voltage divider capacitor 18-2, and the voltage divider capacitor 18-2. ) One side of the lower side is connected to the ground terminal of the power supply transformer 19.

Through this configuration, the auxiliary power supply device 20 and the partial discharge (PD) detection sensor 21 are embedded in the electronic transformer (ECT / EVT) 16 and 17, and molded on the epoxy resin thereon, as shown in FIG. An outdoor high voltage electronic (ECT / EVT) MOF having a single phase structure and a three phase structure as shown in FIG. 2 can be provided.

Hereinafter, a high voltage outdoor epoxy resin mold type electronic (ECT / EVT) MOF having an auxiliary power supply and a partial discharge (PD) detection sensor in the electronic transformer (ECT / EVT) according to the present invention will be described.

<ECT Design and Fabrication>

The electronic current transformer (ECT) 16 has a Rogowski coil (RC) wound around a nonmagnetic core (μ = μ0), and when an integrator is added thereto, it functions as an ECT. Of course, RC's secondary characteristics alone can be defined as ECT, but in general, the use of an integrator is essential, so the two devices cannot be considered separately.

The output voltage of Rogowski coils can be obtained by the following equations (2) and (3).

These Rogowski coils offer high measurement accuracy (1 to 3%), wide current measurement range, frequency range (typically 0.4 Hz to 1 MHz, up to 200 MHz) and resistance to short-circuit currents. Since it is not electrically connected to the primary side conductor and the output is in the form of voltage, it provides an output signal for driving various measuring devices, digital meters, and protection relays, and has the advantage of low production cost.

The design specifications of the ECT to be presented in the present invention is the maximum applied rating is 25.8kV 1500A 50 / 60Hz 150kV BIL, the rated primary current is 5A ~ 2000A (continuous), the rated secondary voltage is 10V ~ 4V, such The output characteristics are produced by selecting the voltage suitable for the domestic situation from the rated output voltage specified in IEC standard.

<EVT Design and Fabrication>

In the present invention, the EVT 17 is designed using the resistance voltage divider method, and the design principle thereof is as shown in FIG.

In order to use the resistance voltage dividing method, the resistance voltage divider must be resistant to Joule heat, have high precision, and must have excellent characteristics for partial discharge (PD) and withstand voltage characteristics (commercial frequency withstand voltage and impulse withstand voltage). It is designed and manufactured by applying the smooth structure, and the high voltage resistance is manufactured in the form of a thin film rather than the general resistance, and it is configured to improve the precision by using the non-inductive resistance.

According to the design specifications, the maximum applicable rating is 25.8kV 50 / 60Hz, 150kV BIL, the rated primary voltage is 22900V / √3, and the rated secondary voltage is 1.32V ~ 6V.

<Design and manufacture of auxiliary power supply>

In the present invention, the auxiliary power supply device 20 is composed of a main capacitor 18-1 and a voltage dividing capacitor 18-2 in a capacitor divided method, and for supplying power connected in parallel to the voltage dividing capacitor 18-2. It is a principle for supplying the auxiliary power required by the transformer 19, and the design principle thereof is as follows.

To use the capacitor divider method, the capacitor divider must have sufficient capacity to secure the desired final output capacity, and the electrical characteristics (commercial frequency withstand voltage, impulse withstand voltage) must be excellent, so that the dielectric constant (2,000 ~ 9,000) and dielectric loss (2.5 It is configured to improve electrical and mechanical properties since the ceramic dielectric having the characteristic of% or less) is molded at high pressure and fired at high temperature (1,300 ~ 1,500 ° C).

In addition, the transformer connected in parallel to the voltage divider capacitor has electrical characteristics (commercial frequency withstand voltage, impulse withstand voltage), low loss, high efficiency, partial discharge (PD) and stable temperature characteristics.

The rated primary voltage is AC 22900V / √3, the rated secondary voltage is AC 40 / √3 to 110V / √3, and the divided voltage (V2) and the main capacitor (C1) for the primary voltage (V1) The relationship between and the partial pressure capacitor (C2) is shown in the following equation (4).

<Design and manufacture of PD detection sensor>

In the present invention, the PD detection sensor 21 is designed by using a partial discharge generation waveform detectable frequency band characteristic, the design principle is as follows.

Capacitor sensor, which uses the capacitor partial discharge (PD) generation waveform detection method, has a capacitor of 100pF or more to satisfy the characteristic from 10MHz (to 3dB cut-off) to a suitable frequency band to secure the output waveform of the desired frequency range. In order to have a quality factor (q) of at least 1000 and to withstand the withstand voltage characteristics (commercial frequency withstand voltage and impulse withstand voltage), and have a partial discharge (PD) characteristic that can be generated by itself for partial discharge detection. Ceramic dielectrics having dielectric constant 500 and dielectric loss (2.5% or less) were molded at high pressure and then fired at high temperature (1,300 ~ 1,500 ° C) to have electrical and mechanically stable characteristics.

The design specifications are 25.8kV 50 / 60Hz, 150kV BIL, and the rated PD detection frequency ranges from 10MHz to 50MHz.

As described above, according to the present invention, it is possible to supply the power without a separate power supply by developing a built-in auxiliary power supply unit in the electronic MOF, it is easy to maintain and has a very efficient and economical effect,

In particular, the epoxy mold-type outdoor electronic MOF manufacturing technology according to the present invention can be widely applied, such as ECT and EVT manufacturing technology, auxiliary power supply and partial discharge (PD) detection sensor manufacturing technology, solid-state insulation circuit breaker and switchgear, economic effect and It has a good effect to contribute to industrial development.

Claims (4)

  The high voltage side conductor 12 for input and output (K, L) connection protrudes to one side of the upper surface, and passes through the center between the high voltage side conductor 12 for input and output (K, L) connection. ECT (Electronic Current Transformer) 16 is formed inside the annular shape, and the high-voltage side conductors 12 and 2 for input and output (K, L) connection on one side of the ECT (Electronic Current Transformer) 16. In the EVT (Electronic Voltage Transformer) 17 is formed to be connected between the vehicle output ground terminal (14-1) is installed in an I-shape, The main capacitor 18-1 and the voltage dividing capacitor 18-2 are paralleled between the high voltage conductor 12 for input and output (K, L) connection and the ground on one side of the EVT 17. An auxiliary power supply device 20 including a connected auxiliary power supply capacitor 18 and a power supply transformer 19 is formed, and the auxiliary power supply capacitor 18 is based on the electronic current transformer (ECT) 16. The partial discharge detection sensor 21 is formed on the opposite side between the high voltage side conductor 12 for input / output (K, L) connection and the second output ground terminal 14-2 in parallel. High-voltage outdoor epoxy resin molded electronic MOF with built-in auxiliary power supply and PD detector in transformer (ECT / EVT). The electronic voltage transformer (EVT) 17 of claim 1, A semicircular shield 17-1 made of a semicircular mesh-type metal screen shield or semiconductive functional synthetic resin is formed at the upper and lower portions thereof, and a main resistance is formed between the upper and lower shields. 17-2), the auxiliary power supply to the electronic transformer (ECT / EVT), characterized in that the voltage divider (17-3) is formed in series with the main resistor (17-2) on one side of the shield of the lower end High voltage outdoor epoxy resin mold type electronic MOF with integrated device and PD detection sensor. The method of claim 1, wherein the auxiliary power supply capacitor 18 The high voltage side conductor 12 for connecting the input / output (K, L) to one side of the upper end of the main capacitor 18-1, which is composed of a capacitor partial pressure system composed of the main capacitor 18-1 and the voltage dividing capacitor 18-2. It is connected to the input terminal of the power supply transformer 19 to one side of the upper part of the voltage dividing capacitor 18-2, and the ground terminal of the power supply transformer 19 to the lower end of the voltage dividing capacitor 18-2. A high voltage outdoor epoxy resin mold type electronic MOF incorporating an auxiliary power supply and a partial discharge (PD) detection sensor in an electronic transformer (ECT / EVT) characterized in that it is connected and formed in a multistage cylindrical shape. delete

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