KR20160020657A - System and Method for Predicting Life of Power Transformer - Google Patents

Abstract

Disclosed are a power transformer lifespan prediction system and a method thereof. The power transformer lifespan prediction method comprises: a step of acquiring data to determine accelerated degradation by measuring a load amount per capacity through a current transformer (CT) in order to figure out a degree of the accelerated degradation of a power transformer; a step of calculating an accelerated degradation index of the power transformer by using the data for determining accelerated degradation; and a step of analyzing a status of the power transformer depending on the level of accelerated degradation by using the accelerated degradation index.

Description

Technical Field [0001] The present invention relates to a power transformer life predicting system and method,

The present invention relates to a power transformer life prediction system and method. More particularly, the present invention relates to a power transformer life predicting system and method for estimating an internal temperature rise and determining a degree of deterioration by measuring a load used for each capacity of a transformer.

As the usage of electric power equipment increases, the amount of electric power consumption increases sharply. Therefore, the total number of inflow transformers used is increasing. Although we have been actively maintaining and repairing power transformers, we have experienced a replacement cycle of equipment installed in the 1980s and '90s when the demand for power consumption increased sharply during the period of economic revival. As a result, the status of transformer failure is expected to steadily increase. In this situation, it is necessary to further improve the soundness diagnosis of the transformer, to provide reliable and effective diagnosis of aging transformer, and to determine the life of the transformer.

Here, the reason why the load density of the transformer gradually increases is due to various causes, and the capacity used is gradually increasing due to industrial power generation and diversification of loads (change from a conventional lamp load to a cooling load). In addition, as the use of electric appliances gradually increases for convenience of use, it is expected that the trend of increasing use of transformers in Korea will continue to increase as follows.

[Table 1] shows the trend of increase of transformer usage in Korea.

Most of the accidents of transformers in Korea are caused by malfunctions such as deterioration or insulation failure. This can be caused by internal defects in the transformer, electrical effects such as thermal effects due to rise in ambient temperature, transient overvoltage, surge voltage, and environmental degradation due to dirt, moisture and dust that cause tracking.

In case of transformer failure, there is a risk of large scale power outage and power quality problem. In case of inflow transformer, if there is oil leakage problem and accident place in urban area, Secondary problems can lead to soil contamination and water pollution (if the insulating oil used in the inflow transformer is light-only, the environmental aspects of PCB contamination). Also, even if a power transformer is used, the size (capacity), voltage, and cooling method of the power transformer may vary, and the characteristics of the transformer may vary depending on the manufacturer and the year of manufacture. In addition, the environment of the installation site (ambient temperature, humidity, salt, dust, special gas, etc.) may also be affected. Therefore, a diagnostic technique that can satisfy various factors is required, and maintenance and management of reliable electric power facilities are required.

Here, the method of determining the degree of deterioration of the inflowing transformer is a method of determining the residual life of the inflowing transformer based on physical, chemical and electrical characteristics such as kinematic viscosity, computation cost, FT-IR, permittivity, moisture content, gas content, insulation strength, However, it is difficult to measure the lifetime in real time because this method is an off-line method. Therefore, a new transformer life prediction diagnosis technology is needed when various technical fields of related industries are converged. In addition, the progress of deterioration of the power transformer and its accessories is very gentle, so it is difficult to observe with the naked eye, and since the number of transformers to be diagnosed is large, in order to find the problems to occur in advance, Life prediction diagnosis technology is needed.

Outside of the country, design measurement technology related to unattended operation of power system, maintenance / repair technology, diagnosis and life prediction is applied in the field. In the measurement and analysis technology, which is the core of diagnosis technology, digital technology, IT, NT and optical measurement technology In comparison with advanced countries, the level of diagnostic and life evaluation technology for power transformers is relatively low. In terms of technology level, the ideas presented in the existing diagnosis and life evaluation methods provide more reliable and efficient Diagnostic technology can be developed.

The present invention provides a power transformer lifetime predicting system and method for estimating the lifetime of a power transformer by determining the load of each transformer, .

It is another object of the present invention to provide a method and apparatus for continuously measuring the deterioration degree of a transformer during a lifetime of the transformer by integrating the external temperature and environmental factors of the transformer, And a method for predicting the life of a transformer for power.

In one aspect, in the power transformer life predicting system proposed by the present invention, a load for each capacity is measured by a current transformer (CT) to determine the degree of deterioration of the power transformer, A data acquiring unit for acquiring data; A data calculating section for calculating an acceleration deterioration index of the power transformer using the acceleration deterioration judgment data collected by the data obtaining section; And a state determiner for receiving the acceleration deterioration index calculated from the data estimator and analyzing the state according to the deterioration degree of the power transformer.

Wherein the data acquisition unit further acquires the acceleration deterioration determination data by an external environmental factor using an environmental factor data measurement sensor and transmits the acceleration deterioration determination data to the data calculation unit, and the data calculation unit collects the acceleration deterioration judgment data in real time, It is possible to estimate the accelerated deterioration index of the transformer for the transformer.

According to another aspect of the present invention, there is provided a method for predicting the service life of a power transformer, comprising the steps of: measuring a load per capacity with a current transformer (CT) to determine the degree of deterioration of the power transformer; Obtaining; Calculating an acceleration deterioration index of the power transformer using the collected acceleration deterioration determination data; And analyzing the state according to the deterioration degree of the power transformer using the acceleration deterioration index.

And acquiring the acceleration deterioration judgment data by external environmental factors using an environmental factor data measuring sensor.

The accelerated deterioration judgment data is collected in real time by being connected to the surrounding environment network to calculate the accelerated deterioration index of the power transformer and determine the degree of deterioration of the power transformer.

According to embodiments of the present invention, a power transformer lifetime predicting system and method for estimating the lifetime of a power input transformer by estimating the temperature rise inside the transformer by measuring a load used for each capacity of the transformer and determining the degree of deterioration Can be provided.

It is another object of the present invention to provide a method and apparatus for continuously measuring the deterioration degree of a transformer during a lifetime of the transformer by integrating the external temperature and environmental factors of the transformer, The present invention provides a power transformer lifetime predicting system and method.

And it can diagnose by using power sensor (CT) on live wire while minimizing damage to equipment, and it can judge the life of power transformer in non-field control tower. The lifetime is determined by measuring the amount of power used in each district, the conditions of the surrounding environment, and the load of the transformer. By predicting the lifetime of the power transformer efficiently and differently from the existing measurement method, . In addition, since it is possible to determine when to replace the power transformer, a plan for replacing the transformer can be established in advance.

FIG. 1 is a diagram illustrating a temperature change of a hot spot according to an overload of a transformer according to an embodiment of the present invention. Referring to FIG.
2 is a block diagram illustrating a power transformer life predicting system in accordance with an embodiment of the present invention.
3 is a flowchart illustrating a method for predicting the life of a power transformer according to an embodiment of the present invention.
4 is a diagram illustrating an example of a deterioration determination method according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating a deterioration determination method based on a load measured in real-time in a single household in a smart grid environment according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Various methods for determining the degree of deterioration of the transformer have been proposed and used. By attaching a gas sensor to a sealed transformer, it is possible to predict the problems caused by the type and ratio of gases generated by deterioration of insulating paper and insulating oil, and a method of estimating various problems (viscosity, dielectric strength, moisture Content, sediment) and so on. Unlike this method, direct measurement inside the transformer using a temperature sensor has the merit that it is possible to construct a surveillance system with simple measurement method and low cost, but it should be installed at the time of manufacture since it should be installed inside the transformer , It is difficult to replace the sensor during the life of the transformer (about 20 years or more). For this reason, it is more advantageous to judge the degree of deterioration of the transformer based on the data obtained by measuring the load using a current transformer (CT) from the outside of the transformer in view of application of the sensor and securing deterioration data.

The present invention is to numerically determine and analyze the degree of deterioration on the basis of the expected rising temperature in a transformer after measuring the CT according to capacity to determine the degree of deterioration of the power transformer. In addition, the data on the environmental factor are also taken into account when judging the deterioration, and the data on the deterioration of the transformer in connection with the network of the surrounding environment are comprehensively judged. This is a method to judge the state of the transformer in real time unlike the passive discrimination method. At present, periodical inspection or real-time inspection is performed only for a large-capacity transformer, but it is a method for increasing the reliability of the power system because it is possible to monitor the deterioration state of all the input transformers.

1 is a diagram illustrating a temperature change of a hot spot according to an overload of a transformer according to an embodiment of the present invention.

Referring to FIG. 1, the increase in the internal temperature of the input transformer with respect to the load can be known from the acceleration deterioration test of the power transformer. For example, the characteristics of a 10 kVA input transformer are 13.2 kV / 230 V in single phase, 60 Hz in frequency, 1.83 in voltage variation, 97.84% in efficiency (power factor = 1.0) The result of applying 712V, which is 185% of the characteristic impedance voltage (385 / 2.92 (v /%)), is internally applied. Here, the temperature change of the hot spot due to the overload of the transformer is overloaded .

Thus, by applying a high load to the inside of the inflow transformer, heat is generated inside the transformer, and the temperature of the insulating oil can be changed according to the load. Based on these results, it is possible to understand the temperature of transformer internal deterioration due to load and application time.

Here, the power transformer can determine the deterioration degree (lifetime) of the transformer by measuring the hot-spot temperature of the portion where the highest heat is generated by measuring the heat sensor and applying a constant formula. For this reason, when a constant value of load is used for the power transformer, the heat generated internally may be constant. Therefore, rather than measuring the internal temperature of the power transformer, The temperature of the heat generated in the hot-spot can be estimated.

The temperature-dependent degradation of the input transformer can be analyzed in accordance with IEEE Std C57.91 (IEEE Guide of Loading Mineral-Oil-Immersed Transformers), and the lifetime of the input transformer at 180,000 [hours] However, depending on environmental factors and various influencing conditions of the transformer installed in such a condition, the load applied to the transformer may be lower, which may be longer than the expected lifetime if the deterioration of the insulating oil does not progress.

According to the IEEE Std C57.91, it is possible to determine the acceleration deterioration index according to the temperature as follows, and it is possible to determine the acceleration deterioration degree according to the change of the acceleration factor according to the proposed formula. It is possible to determine the life of the power transformer.

Table 2 shows the accelerated deterioration index according to one embodiment of the present invention.

)를 산정하기 위해서는 다음 식을 이용하여 구할 수 있다. Hotspot temperature of insulating oil inside transformer (

) Can be obtained by using the following equation.

은 외기온도이고,

은 유입 변압기 권선에 부착된 온도 센서 중 가장 높은 온도 값을 가지는 내부 온도를 나타낼 수 있다.here,

Is the outside temperature,

May represent an internal temperature with the highest temperature value among the temperature sensors attached to the incoming transformer windings.

The system and method for predicting the life of a power transformer according to the present invention is not limited to a method of measuring a temperature inside a transformer, but a relative load according to a capacity of a power transformer is measured using a current transformer (CT) And estimates the deterioration acceleration factor based on the inferred hot spot temperature with respect to the heat generated in the transformer.

The following formula shows the acceleration factor estimation formula, which is to derive the result of accelerated degradation index as shown in [Table 2].

은 [수학식 1]에서 구해진 변압기 내부 절연유의 핫스팟 온도(

)를 나타낸다. 이에 따라, 가속열화지수를 구할 수 있으며, 높은 온도의 경우에도 가속열화지수를 산정할 수 있다. here,

Is the hot spot temperature of the insulating oil in the transformer obtained from the equation (1)

). Thus, the accelerated deterioration index can be obtained, and the accelerated deterioration index can be calculated even at a high temperature.

The following equation shows the equivalent life expectancy, which can be used to calculate the equivalent lifetime by combining the accelerated deterioration index with time.

는 전체시간 동안에 이에 상응하는 가속계수이고,

은 시간 간격(

)의 지수,

은 시간 간격의 총 수이다. 또한,

은 시간간격이고,

은 시간간격(

)에 존재하는 온도의 가속열화 계수를 의미할 수 있다.here,

Is the corresponding acceleration coefficient during the entire time,

Time interval (

),

Is the total number of time intervals. Also,

Is a time interval,

Time interval (

) Of the temperature present in the exhaust gas.

Then, the deterioration degree of the transformer can be calculated at a time when the accelerated deterioration index continuously changes.

The following equation can be used to determine the degree of accelerated deterioration by substituting the estimated equivalent life expectancy.

Here, the normal insulation life is the period for the life of the transformer as shown in [Table 3].

Table 3 is a table showing the life span of the transformer according to one embodiment of the present invention.

This standard establishes lifetime in accordance with the standard of the input transformer proposed in IEEE Std C57.91. It also provides a separate safety factor for facilities that continuously supply power and require a higher safety factor than the economic cost So that the life period can be newly set.

2 is a block diagram illustrating a power transformer life predicting system in accordance with an embodiment of the present invention.

Referring to FIG. 2, the power transformer life predicting system 200 may include a data acquisition unit 210, a data calculation unit 220, and a state determination unit 230.

The data acquisition unit 210 can measure the load amount of each power capacity transformer to determine the degree of deterioration of the power transformer. At this time, it is possible to acquire acceleration deterioration judgment data by measuring load amount by capacity using a current transformer (CT).

The data acquisition unit 210 may further acquire the acceleration deterioration determination data due to an external environmental factor using the environmental factor data measurement sensor, and may transmit the acceleration deterioration determination data to the data calculation unit. Here, the external environment factor means the environment of the place where the power transformer is installed, and may be various environmental factors that may affect the current transformer such as ambient temperature, humidity, salt, dust, and special gas.

The data estimating unit 220 may receive the acceleration deterioration determining data collected by the data acquiring unit 210 to calculate the acceleration deterioration index of the power transformer. At this time, the data calculator 220 may calculate the acceleration deterioration index of the power transformer by collecting the acceleration deterioration determination data in real time. The accelerated deterioration index is preferably calculated using the accelerated deterioration index formula described above.

Here, the acceleration deterioration determination data may be the acceleration deterioration determination data obtained by measuring the load amount of the power transformer by capacity and the acceleration deterioration determination data by the external environment factor.

The state determination unit 230 receives the acceleration deterioration index calculated from the data calculation unit and can analyze the state according to the degree of deterioration of the power transformer. This makes it possible to determine the lifetime according to the deteriorated state of the power transformer, so that it is possible to appropriately deal with this.

Therefore, the deterioration phenomenon may vary depending on the external environment factors as well as the relative load to be measured, so an additional environmental factor data measuring sensor should be applied. Unlike the real-time temperature measurement method, deterioration-related factors can be derived easily and stably, and it is possible to prevent damage to the equipment by installing it outside the transformer, and to operate the sensor during the life of the transformer (about 20 years or more) It is easy to replace when measuring equipment is damaged.

3 is a flowchart illustrating a method for predicting the life of a power transformer according to an embodiment of the present invention.

Referring to FIG. 3, the power transformer lifetime predicting method using the power transformer life predicting system described with reference to FIG. 2 can be shown.

In step 310, the power transformer life predicting system may acquire acceleration deterioration judgment data by measuring a load per capacity with a current transformer (CT) for determining the degree of deterioration of the power transformer.

In step 320, the power transformer life predicting system can acquire the acceleration deterioration judgment data by external environmental factors using an environmental factor data measuring sensor. Here, the external environment factor means the environment of the place where the power transformer is installed, and may be various environmental factors that may affect the current transformer such as ambient temperature, humidity, salt, dust, and special gas.

In step 330, the power transformer life predicting system may calculate the acceleration deterioration index of the power transformer using the collected acceleration deterioration judgment data. At this time, the acceleration deterioration index can be estimated using an accelerated deterioration formula. This has been described above and will be omitted.

In step 340, the power transformer life predicting system may analyze the state according to the degree of deterioration of the power transformer using the accelerated deterioration index.

Accordingly, the accelerated deterioration judgment data can be collected in real time by being connected to the surrounding network, so that the accelerated deterioration index of the power transformer can be calculated, and the degree of deterioration of the power transformer can be determined.

4 is a diagram illustrating an example of a deterioration determination method according to an embodiment of the present invention.

Referring to FIG. 4, the deterioration determination method of the transformer can be performed based on the power transformer life predicting method of FIG.

At step 410, usage load data for each transformer capacity can be obtained to determine the degree of deterioration of the transformer. Then, data can be acquired (411) by the current sensor in order to acquire the used load amount data for each transformer capacity. Here, the current sensor may be a current transformer (CT) provided outside the transformer, but the present invention is not limited thereto.

In step 420, the acceleration deterioration determination data due to external environmental factors can be acquired. Data based on external environmental factors can be obtained by integrating (421) the environmental factor data measurement sensor and the weather station data. Here, the external environment factor means the environment of the place where the power transformer is installed, and it may be various environmental factors that may affect the transformer such as ambient temperature, humidity, salt, dust, and special gas.

In step 430, the measured acceleration deterioration determination data can be transmitted to the estimation section using wireless communication.

In step 440, the accelerated deterioration index over time can be calculated and the condition of the transformer monitored. At this time, the acceleration deterioration index can be calculated using the accelerated deterioration formula (441). This has been described above and will be omitted.

In step 450, the degradation problem of the transformer can be determined using the accelerated degradation index. At this time, it is possible to indicate the state of the transformer by judging the state of the transformer as normal, caution warning, and discard warning.

FIG. 5 is a diagram illustrating a deterioration determination method based on a load measured in real-time in a single household in a smart grid environment according to an exemplary embodiment of the present invention.

Referring to FIG. 5, it is possible to represent a deterioration determination method based on the load measured in real-time in one household in a smart grid environment based on the power transformer life predicting method of FIG.

At step 510, the usage load data of the entire household can be acquired to determine the degree of deterioration of the transformer.

At step 520, the regional unit data can be aggregated by dividing the range of use of the transformer. At this time, data can be acquired (521) by the current sensor in order to obtain the used load amount data for each transformer capacity. Here, the current sensor may be a current transformer (CT) provided outside the transformer, but the present invention is not limited thereto.

In step 530, the acceleration deterioration determination data by external environmental factors can be acquired. Data based on external environmental factors can be obtained by integrating (431) the environmental factor data measurement sensor and the weather data. Here, the external environment factor means the environment of the place where the power transformer is installed, and it may be various environmental factors that may affect the transformer such as ambient temperature, humidity, salt, dust, and special gas.

In step 540, the measured acceleration deterioration determination data can be transmitted to the estimation unit using wireless communication.

In step 550, it is possible to monitor the accelerated deterioration state of the input transformer utilized in a large range.

At step 560, the degradation problem of the input transformer can be determined according to the accelerated deterioration state. At this time, it is possible to indicate the state of the transformer by judging the state of the transformer as normal, caution warning, and discard warning.

Since the power transformer market is related to the power system of the world's countries, it is difficult to change the power transformer and change the model, the speed of technology change (replacement cycle) is slow, and the life cycle of the product It is a relatively long industry. In addition, while the average life span of products is very long, more than 20 years, and it is very difficult to secure the technology in a short period, the technology utilization period can be relatively long. In such an industrial environment, the method of determining the degree of deterioration progress by checking the load usage of a real-time power transformer can be effectively utilized in conjunction with the current development period of the smart grid.

In addition, large power transformers among power transformers are constantly managed. However, small and medium-sized transformers of low capacity do not have a large number of suitable testing methods, and it is difficult to detect problems related to deterioration due to insufficient deterioration test labor, , It has an adverse effect on industries directly affected by electric power quality and has a very large ripple effect on people's lives. Therefore, according to the present invention, it is possible to prevent an expected accident in advance and to induce additional income through additional technology development.

In addition, it is possible to diagnose using active power sensors (CT) on live lines while minimizing damage to the instrument and to determine the life of power transformers in non-field control towers. The lifetime determination data is used to estimate the lifetime of the power transformer by estimating the lifetime of the power transformer efficiently by measuring the amount of power used in each area, the conditions of the surrounding environment, and the load of the transformer. can do. In addition, since it is possible to determine when the power transformer is to be replaced, a plan for replacing the transformer can be established in advance.

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a computer system, such as, for example, a processor, controller, arithmetic logic unit (ALU), digital signal processor, microcomputer, field programmable array (FPA) A programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing apparatus may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (5)

A power transformer life predicting system,
A data acquiring unit for acquiring accelerated deterioration determination data by measuring a load per capacity with a current transformer (CT) provided outside to determine the degree of deterioration of the power transformer;
A data calculating section for calculating an acceleration deterioration index of the power transformer using the acceleration deterioration judgment data collected by the data obtaining section; And
A state determiner for receiving the acceleration deterioration index calculated from the data estimator and analyzing a state according to a deterioration degree of the power transformer,
Wherein the power transformer life predicting system comprises: The method according to claim 1,
The data acquisition unit
Further comprising the step of acquiring the acceleration deterioration judgment data by an external environmental factor using an environmental factor data measuring sensor and transmitting it to the data calculating section,
The data calculation unit
And collecting the acceleration deterioration judgment data in real time to calculate an acceleration deterioration index of the power transformer
Wherein the power transformer life predicting system comprises: In a power transformer life predicting method,
Acquiring acceleration deterioration judgment data by measuring a load per capacity with a current transformer (CT) provided outside in order to determine the degree of deterioration of the power transformer;
Calculating an acceleration deterioration index of the power transformer using the collected acceleration deterioration determination data; And
Analyzing the state according to the deterioration degree of the power transformer using the acceleration deterioration index
Wherein the power transformer is a transformer. The method of claim 3,
Acquiring the acceleration deterioration judgment data by external environmental factors using an environmental factor data measuring sensor;
Further comprising the steps of: The method according to claim 3 or 4,
The accelerated deterioration judgment data is collected in real time by being connected to the surrounding network, and the acceleration deterioration index of the power transformer is calculated, and the degree of deterioration of the power transformer is determined
Wherein the power transformer is a transformer.

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