KR101102547B1 - Deterioration sensor for insulated device and deterioration diagnosis apparatus of the same - Google Patents

Abstract

PURPOSE: A sensor for detecting the deterioration of an electrical insulation device and an apparatus for analyzing a device using the same are provided to improve stability by not influencing on an object under testing even if a malfunction occurs in a sensor. CONSTITUTION: A sensor(2) for detecting the deterioration of an electrical insulation device divides and detects a partial discharge which is generated from an electrical device while being attached to the outer surface of the electrical device. A plurality of first metal plates(4) is connected to be in parallel at a constant interval. A first electrode part(8) is formed at one end of the first metal plate. The first metal plate is inserted into the separation part(6a) of a second metal plate(6). The second metal plate is connected to be in parallel at a constant interval. A second electrode part(10) is formed at one end of the second metal plate.

Description

Degradation detection sensor for electrical insulation equipment and device status analysis device using the sensor {DETERIORATION SENSOR FOR INSULATED DEVICE AND DETERIORATION DIAGNOSIS APPARATUS OF THE SAME}

The present invention relates to an electrical insulation device deterioration detection sensor and an apparatus state analysis device using the sensor, and more specifically, a dry transformer or a solid insulated electric device (mainly an epoxy solid insulation switchgear and a meter using a thin film type capacitive sensor). The present invention relates to a deterioration detection sensor for electrical insulation equipment and a device state analysis device using the sensor, which accurately and safely measure partial discharge of a current transformer and a transformer).

As is well known, the internal elements of a transformer are generally composed of an iron core, a coil, an insulating material, and the like, and the switchgear has a similar configuration, and such a transformer and a switchgear are very important in a power facility for supplying electricity. Although the device is deteriorated due to overheating and discharging during operation, gas generation, etc., it may lead to a serious accident such as an explosion when overloaded.

On the other hand, the epoxy resin is very stable and excellent in mechanical, electrical, thermal, and chemical properties, and in recent years, this epoxy resin is widely used as an insulation for manufacturing various electric devices.

As a representative example, it has been used early to manufacture mold transformers (especially indoor transformers: see Fig. 4, 100) instead of tank-type inlet transformers in which epoxy resin is cured and fire and explosiveness are present. In place of the gas insulated switchgear that has been manufactured using sulfur gas (SF6 gas), the company began to develop and manufacture solid insulation switchgear made by curing epoxy resin without tank and without SF6 gas.

After the general use of electricity by humans, tank type inflow transformers and various types of switchgear devices are managed to prevent accidents (failures) from occurring, and to prevent failures in advance to prevent sudden supply of electricity. The development and use of techniques and devices on how to preventive maintenance have benefited greatly.

However, relatively recently developed dry transformers (especially epoxy mold transformers made by curing epoxy resin) and solid state insulation switchgear are not easy to prevent and prevent sudden failures. It is weak.

In more detail, as described above, the conventional inlet transformer and the switchgear sealed with steel enclosures have been developed and used in order to detect and analyze internal failures in advance and prevent accidents in advance. have.

In case of abnormality due to internal deterioration of internal materials, these devices generate partial discharge (PD = Partial Discharge) at the site. When partial discharge occurs, sound wave by "arc" is generated and insulation oil or gas for insulation When the steel box is reached through (usually SF6 gas), sound waves (ultrasound) are transmitted to the outer wall with fine vibration.

Then, the ultrasonic sensor using the piezoelectric effect is attached to the outer wall to amplify the sound and analyze it with a measuring device with an "oscilloscope" function.

However, in contrast to such conventional equipment, mold transformers and switchgears made of epoxy resins, which are mainly used in recent years, cannot be analyzed by measuring partial discharge using ultrasonic waves because there is no metallic tank capable of receiving such vibrations.

Therefore, as an alternative method, a method of measuring partial discharge by penetrating an annular high frequency CT (Current Transformer) through a device ground wire commonly used in many electrical equipment or by connecting directly to a high voltage side conductor to measure partial discharge. A "capacitor" type transformer (Coupling Capacitor) is used.

However, the former method has a problem that it is difficult to remove the electrical noise and to separate only the intrinsic PD, and the latter method has an electric insulation such as a test object (transformer or switchgear) when the "condenser" type transformer itself is defective. Device), so there are many problems.

That is, there are no ideal "sensors" and analysis devices that can prevent accidents by measuring partial discharge safely and precisely by solving both conventional problems.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described state of the art, and precisely prevents partial discharge of a dry transformer or a solid insulated electric device (mainly an epoxy solid insulated switchgear and an instrument current transformer and transformer) using a thin film type capacitive sensor. The purpose of the present invention is to provide a deterioration detection sensor for electrical insulation equipment and an apparatus for analyzing the state of the equipment using the sensor, which can prevent accidents by measuring safely and safely.

In order to achieve the above object, according to a preferred embodiment of the present invention, a plurality of first parts are attached to an outer surface of an electric device solidified with a resin to separate and detect partial discharge (intrinsic PD) generated from the electric device. The metal plates are connected in parallel in a state spaced apart from each other, the first electrode part is formed at one end thereof, and the first metal plates are respectively inserted into the spaced parts of the second metal plate; A plurality of second metal plates are connected in parallel in a predetermined distance from each other, the second electrode part is formed at one end thereof, and the second metal plate is arranged in a structure in which the second metal plates are respectively inserted in the separation part of the first metal plate, thereby providing a low frequency signal. The electrical insulation device degradation detection sensor is provided so as to cut off and pass a high frequency signal to measure whether a partial discharge of the electrical insulation device occurs.

Preferably, the first metal plate and the second metal plate is provided with an electrical insulation deterioration detection sensor, characterized in that the front and rear surfaces are hermetically coated with a dielectric insulator resin.

Preferably, if the electrical device solidified with the resin is a mold transformer, the electrical insulation equipment degradation detection sensor is attached to the upper surface of the high-pressure mold winding of each phase, and in the case of a solid insulation switch, the electrical insulation device degradation detection sensor An electrical insulator deterioration detection sensor is provided, which is attached to the disconnecting unit part, the ground switch part, the main opening and closing part, and the power receiving device part, respectively.

On the other hand, the present invention includes a high frequency filter / overvoltage protection unit for receiving an analog signal from the electrical insulation device degradation detection sensor passes a high frequency signal and cuts off the overvoltage; A signal amplifier configured to receive and amplify a signal from the high frequency filter / overvoltage protector; An A / D converter converting the analog signal received from the signal amplifier into a digital signal; An apparatus for analyzing a state of a device using an electrical insulation device deterioration detection sensor is provided, wherein the PD analysis diagnosis unit receives a signal from the A / D conversion unit and compares it with a preset signal to determine whether partial discharge occurs.

The electrical insulation device deterioration detection sensor according to the present invention and the device state analysis device using the sensor can detect only the necessary partial discharge signal while simply removing unnecessary noise, and do not adversely affect the EUT even if a failure occurs. This has the advantage of being excellent, and has the advantage of simple installation and economical.

1 is a view showing the external picture of the electrical insulation device deterioration detection sensor according to an embodiment of the present invention,
Figure 2 is a plan sectional view showing the internal structure of the electrical insulation device deterioration detection sensor according to an embodiment of the present invention,
3 is a view showing the external picture of the electrical insulation device deterioration detection sensor and the device connecting line according to an embodiment of the present invention,
Figure 4 is a mold transformer appearance photo showing an installation state of the electrical insulation device deterioration detection sensor according to an embodiment of the present invention,
5 is a block diagram showing the configuration of a device state analysis apparatus using the electrical insulation device degradation detection sensor according to an embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail with reference to drawings.

1 is a view showing an external picture of the electrical insulation device degradation detection sensor according to an embodiment of the present invention, Figure 2 is a planar cross-sectional view showing the internal structure of the electrical insulation device degradation detection sensor according to an embodiment of the present invention, 3 is a view showing the external picture of the electrical insulation device degradation detection sensor and the device connecting line according to an embodiment of the present invention, Figure 4 shows the installation state of the electrical insulation device degradation detection sensor according to an embodiment of the present invention. Mold transformer outline photo (Solid state insulation switchgear, instrument current transformer, and instrument transformer were not shown in the city because of their various shapes and structures.)

Referring to this, the electrical insulation device deterioration detection sensor according to the present invention and the device state analysis device using the sensor is a dry transformer or a solid insulated electric device using a thin film type capacitive sensor (mainly for epoxy solid insulation switchgear and instrument It is a sensor and device that prevents accidents by measuring the partial discharge of current transformers and transformers accurately and safely.

In more detail, the electrical insulation device deterioration detection sensor 2 according to the present invention is a thin film type capacitive sensor, and the electrical equipment (molding transformer, solid state switching device, instrument current transformer (CT = Current Transformer) solidified with resin Attached to the outer surface of the instrument, such as PT (Potential Transformer), to accurately and safely detect partial discharges generated from the devices, and transmit it to the device state analysis device (see FIG. 5: 200) configured on-site or remotely. Means to make the analysis.

The electrical insulation device deterioration detection sensor 2 according to the present invention is a sensor for separating and detecting partial discharge (intrinsic PD) generated from an electrical device by attaching to an outer surface of the electrical device solidified with a resin. The metal plates 4 are connected in parallel in a state where the metal plates 4 are spaced apart from each other, the first electrode portions 8 are formed at one end thereof, and the first metal plates 4 are disposed at the spaced portions 6a of the second metal plates 6. Each has a structure to be inserted; The plurality of second metal plates 6 are connected in parallel while being spaced apart by a predetermined distance, and the second electrode part 10 is formed at one end thereof, and the second metal plate 6 is spaced apart from the first metal plate 4. ) Are arranged so that the low frequency signal (for example, noise) is blocked and the high frequency signal is passed to measure the partial discharge of the electrical insulation device.

Further, the front and back surfaces of the first metal plate 4 and the second metal plate 6 constituting the electrical insulation device deterioration detecting sensor 2 according to the present invention are hermetically coated with a dielectric non-conductive resin 12.

That is, the electrical insulation device deterioration detection sensor 2 according to the present invention is made of a plurality of thin and narrow width of the first and second metal plates (4,6) to the shape of two hair comb each comb cross each other in a state facing each other When the thin film is coated with the dielectric insulator resin 12 such that the first and second metal plates 4 and 6 are positioned inside the upper and lower surfaces thereof, the sensors are manufactured.

Thus, charge is charged between the first comb-shaped first metal plate 4 connected to the first electrode part 8 and the second comb-shaped second metal plate 6 connected to the second electrode part 10. This allows multiple "condensers" to have the same function as the paralleled structure. At this time, the larger the number of "combs", the greater the parallel effect, and the larger the parallel effect, the larger the capacitance.

In addition, when the electrical insulation device deterioration detection sensor 2 according to the present invention is manufactured by forming a large number of combs having a large capacitance, it is possible to sufficiently utilize the electrical characteristics of blocking a low frequency signal and passing only a high frequency. Therefore, it is possible to block a plurality of noise signals generated in the electrical insulation device itself, and to use only the intrinsic partial discharge signal.

Therefore, when partial discharge is generated from the test object which is an electrical insulation device, an electric magnetic field acts on the electrical insulation device deterioration detection sensor 2 according to the present invention, and a signal capable of measuring the amount, size and shape of the partial discharge generation is shown in FIG. 3. Through the device connection line 14 shown in the can be transmitted to the device status analysis device installed in the field or installed in a remote place.

Hereinafter, an example of an electrical insulation device deterioration detection sensor 2 according to the present invention is applied to an epoxy mold transformer and a solid state insulation switch.

The electrical insulation device deterioration detection sensor 2 according to the present invention is a means for detecting a partial discharge signal generated due to deterioration by being attached to an electrical insulation device such as an epoxy mold transformer 100 and a solid insulation switch. It is attached to the outside of the same, but the location and location of the attachment slightly different depending on the characteristics of each device.

First, the epoxy mold transformer 100 is configured in the form of FIG.

The low-pressure mold winding 104 that outputs low pressure around the iron core 106 configured at the top is made of a cylindrical shape, and the high-pressure mold winding 102 in which the high pressure is drawn at regular intervals is also made of a cylindrical shape. It is installed.

Conventional epoxy mold transformer 100 is a short-circuit, insulation deterioration due to poor insulation due to a variety of factors, such as foreign substances in the material during manufacture, air bubbles (bubbles or voids) during the molding process, or contamination of the surface Many accidents such as insulation breakdown occur.

Proactively detecting and dealing with these failures can help prevent transformer burnout and unexpected power outages.

Mold transformer 100 is mainly a failure occurs in the high-pressure mold winding (102), the highest potential of them, the occurrence of the surge from the outside of the upper side is often generated first. Therefore, at least one electrical insulation device deterioration detecting sensor 2 is installed on the upper end of the high-pressure mold winding 102 at least for each phase (A, B, C), so that the internal failure can be measured and analyzed by partial discharge. The partial discharge pulse generates an electric field, which changes the amount of charge of the electrical insulation deterioration detection sensor 2.

On the other hand, as described above, the epoxy resin has been spotlighted as an electrical insulating material because of its excellent properties as various electrical insulating materials, but only weak to the opening and closing surge generated when the switch operates. The opening and closing chamber (not shown) of the solid insulated switchgear (SIS) is made of vacuum, so it can be regarded as having a small vacuum switch and is opened and closed when the solid insulated switchgear (SIS) is opened and closed. Surge may cause cracks in the solid surrounding the switchgear. At first, micro cracks and voids may open and close and deteriorate the insulator over time. It happens first. This electrical situation can be detected early and the electrical insulation equipment deterioration detection sensor (2) can be attached to the solid insulating surface for measurement and diagnosis.

Solid Insulated Switchgear (SIS) is a DS (Disconnecting Switch) part that disconnects the circuit in the state of incidental power failure, and a grounding switch part (ES = Eathing) that disconnects the circuit and connects it to ground for safety. Switch), the main breaker (CB = Vacuum Interrupter Main Circuit Breaker) that opens and closes when a load is applied, and the receiving part (Incoming Part), so it is divided into four parts. The analysis of the PD by attaching the sensor (2) can also be applied to a solid-insulated switchgear.

5 is a block diagram showing the configuration of a device state analysis apparatus using the electrical insulation device degradation detection sensor according to an embodiment of the present invention.

Referring to this, the device state analysis apparatus 200 using the electrical insulation device deterioration detection sensor according to an embodiment of the present invention by receiving a partial discharge signal from the electrical insulation device deterioration detection sensor 2 to analyze the electrical insulation. It is a device that determines whether the device is deteriorated.

More specifically, the device state analysis apparatus 200 includes a high frequency filter / overvoltage protection unit 202 for receiving an analog signal from the electrical insulation device deterioration detection sensor 2 and passing a high frequency signal and blocking overvoltage; A signal amplifier 204 for receiving and amplifying a signal from the high frequency filter / overvoltage protection unit 202; An A / D converter 206 for converting an analog signal applied from the signal amplifier 204 into a digital signal; The PD analysis diagnosis unit 208 receives a signal from the A / D converter 206 and compares it with a preset signal to determine whether partial discharge occurs.

At this time, when looking at each of the components constituting the device state analysis device 200, each of which is a known component, more detailed description thereof will be omitted.

Therefore, the device state analysis apparatus 200 amplifies the partial discharge signal applied from the electrical insulation device deterioration detection sensor 2 and converts the partial discharge signal into a digital signal which can be analyzed to compare each partial discharge pulse with a preset pulse. It is possible to determine whether the electrical insulation device is deteriorated.

On the other hand, the electrical insulation deterioration detection sensor and the device state analysis device using the sensor according to an embodiment of the present invention is not limited to the above embodiments, but various modifications can be made without departing from the technical gist of the invention. .

2: deterioration detection sensor for electrical insulation equipment, 4: first metal plate,
6: second metal plate, 8: first electrode portion,
10: second electrode portion, 200: instrument state analysis device.

Claims (4)

In order to separate and detect the partial discharge (intrinsic PD) generated from the electrical equipment by attaching to the outer surface of the electrical equipment solidified with resin,
A plurality of first metal plates are connected in parallel in a state spaced apart by a predetermined distance, a first electrode portion is formed at one end thereof, and the first metal plates are respectively inserted into the spaced portions of the second metal plate;
A plurality of second metal plates are connected in parallel in a predetermined distance from each other, the second electrode part is formed at one end thereof, and the second metal plate is arranged in a structure in which the second metal plates are respectively inserted in the separation part of the first metal plate, thereby providing a low frequency signal. The electrical insulation device degradation detection sensor, characterized in that to cut off and to pass a high-frequency signal to measure the occurrence of partial discharge of the electrical insulation device. The electrical insulation device degradation detection sensor according to claim 1, wherein the front and rear surfaces of the first metal plate and the second metal plate are hermetically coated with a dielectric insulator resin. According to claim 1, wherein if the electrical equipment solidified with the resin is a mold transformer, the electrical insulation equipment degradation detection sensor is attached to the upper surface of the high-pressure mold winding of each phase, if the solid state switchgear electrical insulation equipment Deterioration detection sensor for electrical insulation equipment, characterized in that attached to the breaker detection unit, the grounding switch unit, the main switchgear, the power receiving device. A high frequency filter / overvoltage protection unit for receiving an analog signal from the electrical insulation device deterioration detecting sensor of claim 1 to pass a high frequency signal and to block overvoltage;
A signal amplifier configured to receive and amplify a signal from the high frequency filter / overvoltage protector;
An A / D converter converting the analog signal received from the signal amplifier into a digital signal;
Apparatus for analyzing the state of the device using the electrical insulation device deterioration detection sensor characterized in that consisting of a PD analysis diagnostic unit for receiving a signal from the A / D conversion unit, and comparing the predetermined signal to determine whether the partial discharge occurs.

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