KR100689226B1 - Apparatus for observation load of voltage transformer - Google Patents

Abstract

The present invention can measure the insulation deterioration in the transformer as well as load measurement to prevent overload operation of the transformer, and analyzes the load variation for the summer when the power demand is the maximum when the value exceeds the set value The present invention relates to a transformer load monitoring device capable of informing an alarm to a central control room, and a device for measuring a load of a power line in the form of a flexible cable, which facilitates safety and installation work for an operator. The monitoring system is a load monitoring device for monitoring a load state of a transformer for distribution, comprising a coil coated with an insulating material, flexible, a load measuring cable for measuring the load of the power line of the transformer, and the load Receive data measured by cable for measurement and make the above data and preset standard Oil as compared to the data monitoring whether the overload of the pole transformer, characterized in that the load comprises a diagnostic means for providing to the central alarm station through a wireless network.

Transformer, load measurement

Description

Apparatus for observation load of voltage transformer}

1 is a block diagram of a transformer load monitoring apparatus according to the prior art

2 is a configuration diagram of the load measuring means of the transformer load monitoring apparatus according to the prior art

3 is a conceptual diagram illustrating load measurement in a ground transformer according to the related art.

4 is a conceptual diagram illustrating load measurement in a columnar transformer according to the related art.

5 shows another example of the load measuring means according to the prior art.

6 is a block diagram of a load monitoring apparatus according to an embodiment of the present invention

7 is a configuration diagram of a cable for load measurement according to an embodiment of the present invention

8 is a configuration diagram of a cable for load measurement according to an embodiment of the present invention

9 is a configuration diagram of a cable for load measurement according to an embodiment of the present invention

10 is a conceptual diagram illustrating load measurement in a ground transformer according to an exemplary embodiment of the present invention.

11 is a block diagram of a load sensing means according to an embodiment of the present invention

12 is a configuration diagram of a load measuring apparatus according to another embodiment of the present invention

* Description of the symbols for the main parts of the drawings *

300: cable for load measurement 320: closed jack

400: load diagnosis means 420: A / D conversion unit

430: data setting unit 440: central processing unit

450: data storage unit 460: load fluctuation trend analysis unit

470: transmitting and receiving module 500,600: first, second sensor

The present invention relates to a load monitoring device of a transformer, in particular, it is easy to measure the current of the power cable connected to the transformer to prevent safety accidents, and to detect the progress of the insulation degradation inside the transformer to detect the progress of the transformer due to insulation degradation It relates to a load monitoring device of a transformer that can prevent explosion accidents.

In general, the ground transformer installed in the ground sidewalk (human road) or the columnar transformer installed in the pole is responsible for transforming the high voltage sent from the substation to a low voltage that can be used in factories and homes. In other words, KEPCO, which supplies electricity, produces electricity from a power plant hundreds of kilometers away from the load center in order to supply power to consumers, and increases the voltage to reduce the loss due to transmission. Therefore, install a substation where the load is crowded and lower it to the distribution voltage (22,900V in the case of KEPCO), then transfer it to the transformer near the user through underground lines or overhead lines and finally step down to normal voltage 380V / 220V.

At this time, the transformer transforms the high voltage into a low voltage, so the primary side voltage (voltage input into the transformer) and the secondary side voltage (voltage output from the transformer) are very high. Therefore, if a small malfunction occurs in the transformer, a fatal safety accident may occur. do.

Malfunction of the transformer is mainly caused by the overload of the transformer. If the overload condition lasts for a long time, the transformer may be fatally damaged. Moreover, if the normal transformer function is not performed due to the malfunction caused by the overload of the transformer. There is a problem that a large voltage or a very low voltage may be supplied to a factory or a home, and even a high voltage is supplied to the factory or home, and even a fire may occur.

That is, in the pole, the primary wire through which electric power is transmitted from the substation passes through the top of the pole, and a predetermined wire is branched from the primary wire so that the primary voltage is input to the transformer. The primary voltage input to the transformer is reduced in voltage by a decompression circuit in the transformer to generate a secondary voltage, and is transmitted to the customer by the secondary wire.

In this case, the decompression process is carried out at a considerable high pressure, so there is a large amount of current change, and a large amount of heat is generated during decompression, so that the transformer frequently suffers from heat. Thus, if a transformer fails, hundreds or thousands of households fail. The electricity supply is cut off, which causes a lot of inconvenience to users.

Therefore, there is a need for a device for monitoring in real time the load of the secondary wire flowing from the transformer to the customer, and load monitoring for real-time monitoring of the voltage and current of the secondary wire, the internal and external temperature of the transformer An apparatus has been proposed.

Hereinafter, a load monitoring device of a conventionally proposed transformer will be described.

Figure 1 shows a load monitoring device of a transformer according to the prior art, Figure 2 is a detailed configuration of the load measuring means shown in FIG.

First, as shown in Figure 1, the load monitoring device of the transformer according to the prior art is largely composed of the load measuring means 100 and the load diagnostic means 200.

Here, the load measuring means 100, as shown in Figure 2, the first bracket for fixing the upper bracket 101, the lower bracket 102, the upper bracket 101 and the lower bracket 102 It consists of two fixing parts 103 and 104 and a screw pin 105.

The load diagnosing means 200 receives the measured value by the load measuring means 100 and converts the measured value into data, compares the data with preset reference data, determines the load state of the transformer, and displays its own display means (not shown). It can be displayed for workers to view or provided to the central control room through wired and wireless communication networks.

Referring to the load measurement process of the ground transformer using the load monitoring device of the transformer as follows.

3 is for explaining the measurement of the load state of the ground transformer using a conventional transformer load monitoring device, as shown in the figure, in general, the ground transformer is divided into a high pressure unit (H) and a low pressure unit (L) The load to be monitored is the low voltage wire.

That is, as shown in Fig. 3, the terminals of X0 to X3 are installed on the low voltage side, one to as many as 9 to 10 wires are connected to each terminal, and the wires are buried underground. . In this state, in order to measure the load state of the wires, first, the first fixing 103 is detached from the upper bracket 101 by loosening the fastening screw 106 formed on the second fixing part 104. Thereafter, by loosening the fastening screw 107 formed on the first fixing part 103 to make the first fixing part 103 loose, and then rotating the upper bracket 101 by 90 ° to provide a space into which the wire can enter. Make. Thereafter, the wire is inserted into the groove formed in the center of the lower bracket 102, and then the rotating upper bracket 101 is returned to its original position, and then the tightening screw 107 formed in the first fixing part 103 is provided. To fix the first fixing part 103, and then, the second fixing part 104 is inserted into the groove 108 formed on one side of the upper bracket 101, and then tightening formed in the second fixing part 104. Tighten the screw 106 to secure it.

Then, when the screw pin 105 is tightened until it touches the wire, the voltage and current, and the internal temperature and the external temperature of the transformer are measured by the screw pin 105. The measured values are transmitted to the load diagnosis means 200.

On the other hand, the load monitoring device of such a transformer can be applied not only to the ground transformer as shown in FIG. 3, but also to the columnar transformer as shown in FIG. This installation process is the same as described above and will be omitted below.

On the other hand, Figure 5 shows another example of a conventional load measuring device, as a structure that is detachable by connecting both of the circular core 10 separated into two by a hook (20) (20a) In order to fasten it to the secondary side wire (not shown), first, one of the hooks 20a is disassembled to separate one side of the core 10, and then the secondary side wire is positioned at the inner diameter of the core 10. The disassembled hook 20a is coupled to its original state to measure the load.

However, the load monitoring system of the transformer as described above has the following problems.

First, current, voltage, internal temperature and external temperature could be measured to prevent overload of the transformer, but it is impossible to measure the deterioration state of internal insulation, which is another cause of the transformer, so that there is still a possibility of transformer failure. do.

Second, when the load measuring device is used in the columnar transformer, the worker must climb the pole directly and fasten it to the secondary wire. In the case of the ground transformer, the worker must fasten the wire directly to the low voltage part, and the load measuring device itself is very hard. In addition, the fastening structure is complicated, and the screw must be loosened and tightened (see FIG. 2), or the hook must be released and coupled, so the installation work is very inconvenient. In particular, when the diameter of the secondary or low voltage side wires is very large or many, it is difficult to install the load measuring device itself, and the worker is in danger of causing a safety accident due to the danger of close proximity to the liveline. It can also be a cause.

The present invention has been made to solve the above problems, an object of the present invention is to provide a transformer load monitoring device capable of measuring the insulation degradation inside the transformer, as well as load measurement to prevent the overload operation of the transformer.

Another object of the present invention is to provide a transformer load monitoring device that can notify the central control room of an alarm when the set value is more than a set value by analyzing a change in load for the summer when the power demand is maximum.

Still another object of the present invention is to provide a transformer load monitoring device that is flexible to configure a load measuring device to facilitate the safety and installation of the operator.

The transformer load monitoring device of the present invention for achieving the above object is a load monitoring device for monitoring the load state of the distribution transformer, consisting of a coil coated with an insulating material (Flexible), the output of the power line of the transformer The load control cable for measuring load and the measured value by the load measuring cable are converted into data, and the data is compared with the preset reference data to monitor whether the columnar transformer is overloaded. It characterized in that it comprises a load diagnostic means to provide.

In this case, the load measuring cable has an insertion outlet so that the end of the cable can be selectively inserted or removed, and the load of the power line can be selectively measured according to whether the cable end is inserted or removed.

In addition, the load measuring cable is provided with a three-way connector, wherein a cable connected to the first direction connector is connected to the load monitoring device, the end of the cable connected to the second direction connector can be selectively connected to the third direction connector The end of the cable connected to the second directional coupler through the output side power line of the transformer in a state where the end of the cable connected to the second directional coupler is separated from the third directional coupler. Measuring load.

Meanwhile, the transformer load monitoring apparatus of the present invention further includes a first sensor attached to an enclosure of the transformer to measure an insulation degradation state inside the transformer, and a second sensor for measuring a temperature inside the transformer. It features.

In addition, the load diagnosis means according to the transformer load monitoring device of the present invention, the A / D conversion unit for converting the output signal of the load measuring cable and the first and second sensors into a digital signal, and the overload state of the transformer The load setting value of the transformer is determined by comparing the data setting unit for setting the overload condition data to be compared with the load measurement value input from the A / D converter and the condition data set by the data setting unit. A central processing unit, a data storage unit for temporarily storing and accumulating the load measurement values measured by the load measuring cable and the insulation deterioration state and temperature data in the transformer measured by the first and second sensors; A load variation trend analysis unit for analyzing a trend of load variation by analyzing data stored in the storage; and a control signal of the central processing unit. According to the central control room characterized in that it is configured to include a transmission and reception module for output analysis of load change trend and optionally an alarm signal.

Here, the data setting unit includes receiving data output from the central control room through the transmission and reception module and setting reference data for determining a load level of the transformer.

In addition, the sensor unit is composed of a capacitively coupled sensor, and is attached to the steel enclosure of the transformer, transient grounding of the high frequency induced on the surface of the enclosure by the surface effect of the high frequency induced by the partial discharge generated inside the transformer Measure the voltage and provide it to the load diagnostic means.

[Example]

Hereinafter, a transformer load monitoring apparatus according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 6 is a configuration diagram of a transformer load monitoring apparatus according to an exemplary embodiment of the present invention, wherein the coil is configured in the form of a cable coated with an insulating material and has a very flexible load measurement cable 300. Load diagnosis means for receiving the load measurement value measured by the load measurement cable 300 to make it data and display it for the operator to see through its own display means (not shown) or to provide to the central control room connected via wired or wireless communication network And 400.

Here, as shown in Figure 7, the load measurement cable 300, because the soft insulating material is in the form of a coil covering, so that the flexible itself can be easily bent or bent, the load measurement The end 310 of the cable 300 is selectively inserted into or removed from the closing jack 320 to selectively measure the load of the power line.

That is, since the load measuring cable 300 is a flexible structure, and is composed of only a coil coated with an insulating material, unlike the conventional method, the load measuring cable 300 is very easy to install for load measurement. In other words, the end of the cable is removed from the closing jack 320, the wire is wrapped, and then the end 310 of the load measuring cable 300 is inserted into the closing jack 320 so that the load measuring operation is easy and the wire The load can be measured without any influence on it.

In addition, the load measuring cable 300 according to the embodiment of the present invention, as shown in Figure 8 and 9, provided with a three-way connector, the cable connected to the first direction of the connection to the load diagnostic means The power line of the transformer on the output side of the transformer in a state in which the end of the cable connected to the second directional connector is selectively connected to the third directional connector and the terminal of the cable connected to the second directional connector is separated from the third directional connector. And measuring the load of the power line by inserting an end of the cable into the third direction connector after interposing the cable.

For reference, the conventional load measuring means as shown in FIG. 3 may generate heat or fire when the contact is poor in the second direct connection method, and may cause instantaneous sparking during fastening, but is always exposed to safety accidents. The load measuring cable 300 of the present invention has no fear of heat generation or fire due to contact resistance, and since the coil is coated with a soft insulating material, no spark occurs even when tightening, thereby ensuring the safety of the worker first. You can do it.

Typically, several windings are wound on the primary side (input of the transformer), while hundreds or thousands of windings are wound on the secondary side (output of the transformer), so that the voltage induced on the secondary side under the same power is high and the current is low. Measure the voltage through a constant resistor. The conventional load measuring means mentioned above is a fastening structure in the form of a hook. In order to allow the power line to pass through the circular core, the core is divided into two and the cable is placed in the core and then restored to its original state. In the form of a loop, the winding in the middle becomes the primary winding, and the secondary winding wound on the iron core can display the current value. However, such a conventional load measuring means has to be rigid and fixed at all times because of the use of iron cores, so it is very complicated and careful to install the load measuring means at the work site. Although it is converted to a low current value by the turns ratio, when the operator does not put a load on the secondary side, it acts as a boost transformer, and a high voltage is generated, which may cause injury to the worker and fire.

However, in the present invention, the load measuring cable 300 according to the load monitoring device of the transformer is very flexible in itself because it is made of only a coil coated with an insulating material without an iron core. Therefore, it is very easy for the operator to measure the load, and the voltage induced on the secondary side is only a few mV level, thus ensuring the safety of the operator and measuring the current in various frequency bands.

On the other hand, Figure 10 is for explaining the load measurement state in the ground transformer using a transformer load monitoring device according to an embodiment of the present invention, the terminal 310 of the load measurement cable 300 from the closing jack 320 After removing, the operator grasps the end 310 of the load measuring cable 300 and wraps the desired wire (one strand or more), and then terminates the end of the load measuring cable 300. When the 310 is inserted into the closing jack 320 again, the degree of the load of the wire, preferably the current, is measured by the load measuring cable 300, and the measured value is diagnosed through the transmission line 330. Delivered to the means 400.

At this time, since the load measuring cable 300 is flexible, the cable for bending is flexibly bent or bent, so that even if a lot of wires are wired inside the enclosure (made of metal) of the ground transformer, one of the wires is It is also very easy to wrap around or wrap several wires at once.

In addition, the transformer load monitoring apparatus according to an embodiment of the present invention further includes a first sensor for measuring an insulation degradation state inside the transformer and a second sensor for measuring temperature inside the transformer. The first sensor and the second sensor may be attached to the enclosure of a transformer made of metal by a magnet or the like, and the sensors and the load diagnosis means 400 are connected by a signal line.

As shown in FIG. 11, the load diagnosis means 400 includes data and load measurement cables measured by the first sensor 500 and the second sensor 600 for measuring the insulation degradation state inside the transformer. An A / D converter 420 for converting the load measurement value measured by 300 into a digital signal, a data setting unit 430 for setting overload condition data to be compared to determine an overload condition, and A A central processing unit 440 for determining a load degree of the transformer 103 by comparing the load measurement value input from the / D converter 420 with the condition data set by the data setting unit 430, and the load measuring device. A data storage unit 450 for temporarily storing the load measurement values measured by the 300 and the first and second sensors 500 and 600 and the insulation deterioration state data and the temperature data inside the transformer, and the data By analyzing the data stored in the storage unit 450 It includes a load change trend analysis unit 460 for analyzing the trend of the load change, and a transmission and reception module 470 for outputting a warning signal to the central control room (not shown) in accordance with the control signal of the central processing unit 440. .

In addition, the load diagnosis means 400 amplifies the output signal of the first and second sensors 500 and 600 and the output signal of the load measuring cable 300 to a predetermined width to A / D conversion unit An amplifier (not shown) output to 420 may be further included, and the data setting unit 430 may include setting a data value by receiving a setting value from the central control room through the transmission / reception module 470. .

The first sensor 500 is for detecting the degree of insulation degradation inside the transformer, preferably composed of a capacitive coupling sensor, and is attached to the enclosure of the transformer by a magnet or the like to be part of the transformer. Due to the surface effect of the high frequency induced by discharge, the degree of insulation deterioration is measured by measuring the transient earth voltage (TEV) of the frequency induced on the surface of the enclosure. In general, the transformer can be accurately determined only by simultaneously detecting the current, the voltage of the wire and the temperature of the transformer and whether the internal insulation deterioration progresses. In the present invention, the current and voltage of the wire using the load measuring device 300 and the transformer It measures the temperature of, and monitors the progress of insulation degradation inside the transformer by using the capacitive coupling sensor constituting the sensor unit 410 attached to the transformer enclosure.

In general, the progress of insulation deterioration inside a transformer can be measured by mounting a UHF sensor on the transformer, but such a high frequency sensor is applicable only to a power plant or a substation, and is actually distributed in several places. It is difficult to apply to). In particular, the measurement of the partial discharge inside the transformer has a problem that it is difficult to accurately measure only by the antenna receiving equipment, and it is difficult to compare with external noise.

However, in the present invention, the capacity of measuring the transient ground voltage of the high frequency induced on the surface of the enclosure due to the surface effect of the high frequency induced by the partial discharge generated inside the transformer, taking into account that the transformer enclosure is made of metal. Measure the deterioration of insulation inside the transformer using a gender coupled sensor.

In the meantime, the data storage unit 450 temporarily stores the insulation deterioration progress state data inside the transformer by the sensor unit 410 and the load measurement value measured by the load measuring device 300 to analyze the load variation trend. The data is provided to enable analysis of the load variation trend by the unit 460. In this case, the data storage unit 450 may store load measurement values and insulation degradation state data inside the transformer for at least 30 days.

The load variation analysis unit 460 analyzes the load variation trend based on the load measurement value stored in the data storage unit 450, and provides the analyzed data to the central control room through the transmission / reception module 470. As such, by analyzing the change in load based on the data accumulated in the data storage unit 450, it is possible to stably supply power by preventing failure of the transformer 103 in advance through load analysis in summer, when the demand for power is maximum. have.

Hereinafter, the current monitoring process in the ground transformer using the load monitoring device as described above will be described.

The voltage supplied from the substation or power plant is supplied to the ground transformer through overhead lines and underground lines, and at this time, the load measuring cable 300 connected to the output terminal of the transformer detects the magnitude of the current output from the ground transformer. do. The detected current is converted into a voltage signal proportional to the magnitude of the current, amplified to a predetermined width, and then input to the A / D converter 420. The A / D converter 420 converts the digital signal. By outputting to the central processing unit 440, the central processing unit 440 recognizes the magnitude of the current output from the ground transformer 103. At this time, the central processing unit 440 records the magnitude of the current in the data storage unit 450 so that the load change trend can be analyzed by the load change trend analysis unit 460 later.

Meanwhile, a reference value for determining an overload condition is set in the data setting unit 430, and the central processing unit 440 inputs a current value input from the A / D converter 420 to the data setting unit 430. If it is smaller than the set reference value, the current output from the ground transformer is determined to be normal, and if it is larger than the reference value, it is determined to be an overload. To this end, the central processing unit 440 reads the reference value set in the data setting unit 430 and compares it with the current value input from the A / D conversion unit 420 to determine the occurrence of overload or normal operation according to the comparison result. Proper control will be performed. For example, if it is determined that the central processing unit 440 is overloaded, the transmission and reception module 470 transmits an alarm signal indicating that the current columnar transformer 103 is in an overloaded state to the central control room.

On the other hand, the load change analysis unit 460 analyzes the load change trend based on the load measurement value accumulated in the data storage unit 450, the analyzed data under the control of the central processing unit 440 the transmission and reception module ( 470) is provided to the central control room so that appropriate provisions can be made to meet trends in load changes.

Although a preferred embodiment of the present invention has been described above, the present invention may be easily manufactured by carrying a flexible load measuring device as shown in FIG. 12 using various changes, modifications, and equivalents. As a result, it is clear that the above-described embodiments can be appropriately modified and applied in the same manner. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, the transformer load monitoring apparatus of the present invention has the following effects.

First, the current, voltage, internal temperature and external temperature can be measured to prevent overload of the transformer, as well as the deterioration of internal insulation, which is another cause of the transformer, can be measured. It can be shut off in advance, allowing stable power supply.

Second, the load measurement values are accumulated and stored, and based on the analysis of load variation, appropriate precautions can be taken in preparation for the summer when the demand for electricity is greatest.

Third, it is easy to install the device by measuring the load of the power line (Flexible) flexible, and above all, to ensure the safety of the operator can prevent human injury in advance.

Claims (7)

In the load monitoring device for monitoring the load state of the distribution transformer, Consists of a coil coated with an insulating material and has a closing jack having an insertion and exit hole so that the end can be selectively inserted or removed, and combining the closing jack and the end to center the output power line of the transformer to be measured A load measurement cable for measuring the load of the power line on the output side of the transformer in a wrapped state; It includes a load diagnosis means for receiving the measured value by the load measurement cable to make data and compare the data and the preset reference data to monitor whether the columnar transformer is overloaded and provide it to the central control room through wired and wireless communication networks. Transformer load monitoring device, characterized in that. delete According to claim 1, wherein the load measurement cable, A cable having a three-way connector and connected to the first direction connector is connected to the load diagnosing means, and an end of the cable connected to the second direction connector is selectively connected to the third direction connector so that the cable is connected to the second direction connector. The load of the power line is measured by inserting the end of the cable into the third direction connector after interposing the power line of the transformer with the end of the cable connected to the connector separated from the third direction connector. Transformer load monitoring device. The transformer according to claim 1, further comprising a first sensor attached to an enclosure of the transformer for measuring an insulation degradation state inside the transformer, and a second sensor for measuring a temperature inside the transformer. Load monitoring device. The method of claim 4, wherein the load diagnosis means, An A / D converter for converting the load measurement cable and output signals of the first and second sensors into digital signals; A data setting unit for setting overload condition data to be compared to determine an overload condition of the transformer; A central processing unit for comparing the load measurement value input from the A / D conversion unit with the condition data set by the data setting unit to determine the load degree of the transformer; A data storage unit for temporarily storing and accumulating the load measurement value measured by the load measuring cable and the insulation deterioration state and temperature data in the transformer measured by the first and second sensors; A load fluctuation trend analyzing unit analyzing the data fluctuation trend by analyzing the data stored in the data storage unit; Transformer load monitoring device, characterized in that it comprises a transmission and reception module for outputting the load change analysis data and optionally an alarm signal to the central control room according to the control signal of the central processing unit.  The method of claim 5, wherein the data setting unit, Transformer load monitoring device, characterized in that for setting the reference data for determining the load degree of the transformer by receiving the data output from the central control room through the transmission and reception module. The method of claim 4, wherein the first sensor, Consists of a capacitive coupling sensor, and is selectively attached to the steel enclosure of the transformer to be detachably attached to the grounding of the high frequency induced on the surface of the enclosure by the surface effect of the high frequency induced by the partial discharge generated inside the transformer Transformer load monitoring device, characterized in that by measuring the voltage to measure the insulation degradation inside the transformer.

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