WO2016006994A1 - Electronic device for online monitoring of the moisture content of the paper of a potential transformer subjected to overloading, diagnosis of the safe operating time therein, and corresponding method - Google Patents

Electronic device for online monitoring of the moisture content of the paper of a potential transformer subjected to overloading, diagnosis of the safe operating time therein, and corresponding method Download PDF

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Publication number
WO2016006994A1
WO2016006994A1 PCT/MX2015/000100 MX2015000100W WO2016006994A1 WO 2016006994 A1 WO2016006994 A1 WO 2016006994A1 MX 2015000100 W MX2015000100 W MX 2015000100W WO 2016006994 A1 WO2016006994 A1 WO 2016006994A1
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Prior art keywords
transformer
electronic device
paper
temperature
oil
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PCT/MX2015/000100
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Spanish (es)
French (fr)
Inventor
Berenice BAHENA DE LEÓN
Enrique BETANCOURT RAMÍREZ
Alberth PASCACIO DE LOS SANTOS
David PONCE DE NOYOLA
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Prolec Ge Internacional, S. De R.L. De C.V.
Instituto De Investigaciones Eléctricas
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Application filed by Prolec Ge Internacional, S. De R.L. De C.V., Instituto De Investigaciones Eléctricas filed Critical Prolec Ge Internacional, S. De R.L. De C.V.
Publication of WO2016006994A1 publication Critical patent/WO2016006994A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection

Definitions

  • the present invention is located in the field of electronics. Specifically, the present invention relates to an electronic device designed to monitor and determine in line, the humidity in the role of a power transformer, preferably columns type, and diagnose the safe operating time, in which the transformer can be subjected at an overload, without the risk of generating water vapor bubbles inside the transformer;
  • the electronic device also has two microcontrollers where two mathematical models are implemented to determine the percentage of moisture in the paper and the temperature of bubble generation, in addition to a third model with which the percentage of life loss of the transformer is estimated and the maximum Hot Spot temperature reached during the application of the overload.
  • the insulating system (paper and oil) degrades over time, this process depends on the thermal and electrical conditions to which it is subjected, as well as factors such as water or oxygen that can be introduced into the system accelerating its aging process.
  • changes in temperature cause the migration of moisture between the paper and the oil.
  • the humidity migrates from the paper to the oil and when the temperature drops, the humidity returns to the paper.
  • This phenomenon modifies the dielectric properties of insulating paper and produces accelerated paper aging, increasing the risk of transformer failure conditions.
  • US Patent 8, 149, 003 describes a system that allows determining the moisture content of a transformer, said system comprises the steps of measuring the dielectric properties and the insulation temperature depending on the frequency of a voltage which is applied to the transformer; apply different dielectric responses; and apply a formula by which dielectric responses and / or dielectric properties are determined, however this measurement is performed offline.
  • US 7,516,651 refers to a method for determining the water content of a solid insulator in a specific place within a transformer, said method comprising determining the temperature of a solid insulator, calculating the relative humidity saturation of the oil, calculate the last water content and calculate the recent water content, said measurement is done online.
  • Patent OS 6, 779, 385 shows a device for monitoring the moisture content of a solid dielectric material within an enclosure, said material immersed in a dielectric fluid; the device comprises means for measuring humidity, means for measuring temperature and electronic circuit means for capturing data regarding the level of humidity, in this case the calculation is made based on the variation of the solubility of the water with respect to the temperature, the humidity in the oil and the temperature of the oil.
  • the international application WO / 2007/038845 describes a system for measuring and monitoring the amount of moisture of insulating oil in transformers, said system comprises a sensor module that is in contact with the oil and an interface of the module, which allow the measurement and Oil moisture monitoring, the system allows you to program limit values so that when these are exceeded a series of alarms is activated, the measurement is done online.
  • EP 2, 348, 307 refers to a device and method for in-line diagnostics and control of the dielectric behavior of transformers using an online reader of the relative humidity of the oil and its temperature, which determines the dielectric strength of the oil which allows a change in the operating regime of a transformer to effectively prevent any decrease in the dielectric strength of the oil below the limits required by the standard.
  • an objective of the present invention is to provide an electronic device to determine the ability to safely hold the temporary overload conditions and their application time in a power transformer, in addition to a timely diagnosis for the prevention of failures already which determines the moisture content in insulating paper of the coils, without the need to take out the operating transformer, as well as the temperature of bubble generation, which minimizes the risk of a Possible catastrophic damage to the equipment.
  • a further objective of the present invention is to provide an electronic device that uses a second mathematical model by means of which, with the result of the percentage of humidity determined by the previous model, it can estimate the time limit in which a transformer can be subjected to an overload before it exceeds the temperature threshold for generating water vapor bubbles.
  • processing unit in which the mathematical models with which calculations are made to estimate the percentage of moisture content in the paper are implemented.
  • the mathematical models with which calculations are made to estimate the percentage of moisture content in the paper are implemented.
  • the distribution of humidity in the axial height of the coils in addition to the calculation of the bubble generation temperature and the estimation of the loss of life thanks to the maximum Hot Spot temperature which is also calculated in the processing unit; the other, exclusively carries out communication processes, protocols and storage in memory.
  • an objective of the present invention is to provide an electronic device that uses a graphical interface where the maximum overload time applied to a power transformer can be evaluated, without exceeding the temperature where the generation of steam bubbles will begin of water due to the moisture content in the insulating paper of the coils, as well as estimating the percentage of loss of life and the maximum hot spot temperature reached in the overload.
  • Figure 1 refers to the variables introduced in real time to the microcontroller through analog signals.
  • Figure 2 shows a block diagram of the electronic conceptual design of the device
  • Figure 3 shows a block diagram that indicates the logical sequence that the microcontroller follows to execute the mathematical algorithms of the models.
  • Figure 4 shows a block diagram with respect to the input variables used by the mathematical model to calculate the maximum hot spot temperature and the percentage of life loss of the transformer.
  • Figure 5 shows a block diagram with respect to the input variables to the mathematical algorithm and the flow chart executed by the microcontroller to calculate the percentage of paper humidity of the coils and the humidity in the paper in 4 thermal zones distributed equidistantly at the height of the winding.
  • Figure 6 shows the input variables of the mathematical model that estimates the bubble generation temperature as well as the block diagram of the execution process of the instructions programmed in the microcontroller
  • the present invention relates to an electronic device designed to determine in line, the moisture content in the paper of the winding and the distribution of moisture in the paper in 4 thermal zones distributed equally in the height of the winding of a power transformer type columns .
  • the device has the ability to estimate in line, the temperature of the generation of water vapor bubbles, the maximum hot spot temperature and the percentage of loss of life in the conditions under which the transformer is operating.
  • the electronic device of the present invention uses a graphical interface that allows to evaluate the safe operating time, in which a power transformer, preferably columns type, can be subjected to an overload, without the risk of generating Water vapor bubbles inside the transformer.
  • the device is limited to column type transformers.
  • the electronic device acquires four analog input signals which are sent to a conditioning module to be processed for digital conversion;
  • the first signal is for the oil temperature, which is taken by a temperature indicator (1) installed on the top of the transformer, which sends the measurement to the input module of the device through a 4-20 mA signal ;
  • the second input is used to measure the moisture content of the oil using a specialized device to determine the humidity (2) in the oil in ppm, the measurement result is sent to the input module by a 4-20 mA signal;
  • the third analog input is used to collect the values of the transformer load current, for which a core type current transformer (3) is used, with which the current in the line of one of the current transformers is measured installed in the transformer, this measurement is sent via an analog 4-20 mA signal to the input module;
  • the fourth input of the analog module is used for the acquisition of the ambient temperature value, which is measured with a resistive temperature detector (RTD) (4).
  • RTD resistive temperature detector
  • the analog signals are sent to the conditioning module to be conditioned and subsequently transmitted to the conversion module where the analog to digital signals will be changed, these are sent digitally to a microcontroller.
  • a microcontroller which works as a processing unit, where the three mathematical models that carry out the online diagnosis are implemented, the The microcontroller is in charge of executing the algorithms of the models and interpreting the instructions contained in the program and processing the data, the device also has another raro-controller that performs functions exclusively of communication processes, protocol management and memory storage, the device Electronic also has a unit dedicated to the storage of information, Figure 2 shows the conceptual electronic design of the present invention.
  • FIG. 1 shows the installation of the instruments that perform the online measurement of the analog variables used by the mathematical algorithms programmed in the microcontroller principal.
  • Figure 3 shows the sequence that the microcontroller follows to run the models, First the thermal model that estimates the maximum hot spot temperature that will be reached during a certain period of time is executed, then the model is run to determine the moisture content in the paper, the results of this moisture calculation are used by the bubble generation temperature model, which is the last model to be executed, once the three models have been executed, the microcontroller has implemented the necessary programming to perform the evaluation of the maximum hot spot temperature and the bubble generation temperature with that will evaluate the period of time in which there will be no risk of bubble generation and l percentage of transformer life loss.
  • the first model that is run is based on the standard of IEEE C57.91-1995 this calculates the maximum hot spot temperature that will be reached in an overload and the percentage of life loss of the transformer due to the temperature, the microcontroller uses the parameters of mechanical, electrical and thermal design previously programmed in the device and the digitally conditioned and converted data that were taken by the sensors installed in the transformer to perform the online diagnosis,
  • Figure 4 shows a block diagram of the process that the microcontroller follows to perform the calculation model execution of hot spot and percentage of loss of life, after executing the previous model the microcontroller runs the algorithm to estimate the percentage of moisture contained in the paper of the coils, to perform this calculation the model uses the parameter programmed offline of the acidity in the oil and the digital values of the variables measured in line of the content of humidity in the oil and the temperature of the oil industry
  • Figure 5 shows the variables that the microcontroller uses to execute the mathematical model that determines the percentage of moisture content in the paper and the distribution of moisture throughout the winding, it should be noted that the algorithm Mathematical to determine the humidity
  • the algorithm After calculating the percentage of moisture in the paper by the second model, this result will be used as input of the third mathematical model to estimate the temperature of water vapor bubble generation, the algorithm also uses the digital values taken in line of the oil temperature sensor (1), the ambient temperature (4) and the percentage of load (3), as well as the data programmed in the microcontroller of the atmospheric pressure and the degree of polymerization, Figure 6 It shows the block diagram of the model execution process and the input variables for estimating the bubble generation temperature.
  • the graphical interface will allow the user to evaluate online if the transformer is in a position to accept an overload.
  • the graphical interface uses three types of input data to be able to execute the mathematical algorithms, the first are the fixed values , which are the parameters of the specific mechanical, electrical and thermal design of the transformer, these values will not change once programmed in the software, the seconds are the reprogrammable values that are the parameters of the condition of the paper-oil insulating system, these values are obtained through physicochemical tests of the oil and must be periodically updated in the programming, the third parties are the online values, these parameters determine the current operating condition of the transformer, and are obtained by means of the sensors installed in the transformer that measure in time actual oil temperature parameters, temperature ura environment, transformer load and the percentage of moisture in the oil, these values will be changing over time according to the operation of the transformer.
  • the interface uses all input parameters to estimate online; the moisture content in the paper of the coils, the distribution of moisture in the paper along the axial height of the winding, the generation temperature of water vapor bubbles, the maximum hot spot temperature and loss of life in the current conditions under which the transformer is operated.
  • the graphical interface has a module to estimate offline the evolution of the generation of water vapor bubbles when a power transformer is subjected to a temporary overload
  • the software uses as input values, the level of overload, the time of application of the overload, the humidity in the paper, the temperature of the oil, the ambient temperature and the atmospheric pressure, with these parameters the graphical interface can estimate the maximum time to which a transformer can be subjected to an overload, without the risk of generating water vapor bubbles inside is presented, in addition the software will allow to know the maximum hot spot temperature to which the transformer will be subjected during the temporary overload and its consequent loss of life due to the hot spot temperature reached during overload.
  • the interface can also estimate the moisture content in the transformer winding off-line, in order to perform the calculation the humidity input variables in the oil, acidity in the oil and oil temperature must be entered, with these three input parameters
  • the software determines the percentage of humidity in the paper of the reels and the axial distribution of the humidity in the paper, in 4 thermal zones distributed equally in the height of the winding. The software allows to know online the humidity conditions of the insulating paper without the need to remove the operating transformer.
  • the graphical interface has numerical indicators and graphs of the device's outputs, numerical indicators and graphs of historical values of the device's outputs, configuration operating in the mode of Ethernet TCP / IP and RS-232 communication, however it is possible to use an adapter for a Modbus or DNP communication.3.
  • the software was developed for monitoring up to 32 devices connected to the same Ethernet network where the equipment is operating, the software has a module where the IP address to which another electronic device is connected is assigned, once the IP address of the device is programmed another device the software can automatically display on the main screen the results of the online diagnosis of the added transformers.
  • the software has two modes of operation one to allow the user to monitor and another to configure (Hardware).
  • the monitoring mode brings the information stored in the electronic device to the user PC and displays the results of the calculation of the models and the configuration mode sends the configuration information to the device and the offline parameters that will be programmed in the unit of central processing of the device to perform the calculations of the mathematical algorithms.
  • the computational tool has an additional module that allows estimations of the percentage of overload and the application time, to which it can be subjected to a transformer in operation, without this presenting a risk of generating water vapor bubbles, the interface also determines the maximum hot spot temperature that will occur due to the overload and the percentage of life loss of the transformer as a result of it.

Abstract

The invention relates to an electronic device designed to determine online the moisture content of the paper, the bubble-generating temperature, and the loss-of-life percentage of column-type potential transformers. The diagnosis is performed by way of input data which combine the information collected in real time concerning the actual state of the transformer and the information programmed offline concerning the specific design features of the transformer and the state of the paper-oil insulating system. The device comprises communication software enabling all the diagnosis values to be displayed from a remote computer in real time, as well as a graphic interface comprising an additional diagnostic module, designed to be used as a tool to assist in the decision-making process for the management of the transformer load, which uses three mathematical models obtained experimentally, simulating the thermal and dimensional conditions of a potential transformer, obtaining a dynamic estimate of the migration of the moisture which is more accurate than static equilibrium curves, the models programmed in the microcontroller estimating the overload level and its application time in order to continue safely operating the transformer in overload conditions, at the same time the computational tool estimating the maximum hot spot temperature reached during the period of time in which the transformer remains in overload, and calculating the loss-of-life percentage caused by the increase in temperature.

Description

DISPOSITIVO ELECTRÓNICO PARA MONITOREO EN LÍNEA DE LA HUMEDAD) ELECTRONIC DEVICE FOR MONITORING IN HUMIDITY LINE)
EN EL PAPEL DE UN TRANSFORMADOR DE POTENCIA SOMETIDO A SOBRECARGA T DIAGNÓSTICO DEL TIEMPO SEGURO DE OPERACIÓN EN ELIN THE ROLE OF A POWER TRANSFORMER SUBJECTED TO OVERLOAD T DIAGNOSIS OF THE SAFE TIME OF OPERATION IN THE
MISMO, Y PROCESO SAME, AND PROCESS
CAMPO DE LA INVENCIÓN FIELD OF THE INVENTION
La presente invención se ubica en el campo de la electrónica. Específicamente, la presente invención se refiere a un dispositivo electrónico diseñado para monitorear y determinar en linea, la humedad en el papel de un transformador de potencia, preferentemente tipo columnas, y diagnosticar el tiempo seguro de operación, en el cual el transformador puede ser sometido a una sobrecarga , sin que se presente el riesgo de generación de burbujas de vapor de agua en el interior del transformador; asimismo el dispositivo electrónico cuenta con dos microcontroladores en donde están implementados dos modelos matemáticos para determinar el porcentaje de humedad en el papel y la temperatura de generación de burbujas, además de un tercer modelo con el que se estima el porcentaje de perdida de vida del transformador y la temperatura máxima de Hot Spot alcanzada durante la aplicación de la sobrecarga. ANTECEDENTES DE LA INVENCIÓN The present invention is located in the field of electronics. Specifically, the present invention relates to an electronic device designed to monitor and determine in line, the humidity in the role of a power transformer, preferably columns type, and diagnose the safe operating time, in which the transformer can be subjected at an overload, without the risk of generating water vapor bubbles inside the transformer; The electronic device also has two microcontrollers where two mathematical models are implemented to determine the percentage of moisture in the paper and the temperature of bubble generation, in addition to a third model with which the percentage of life loss of the transformer is estimated and the maximum Hot Spot temperature reached during the application of the overload. BACKGROUND OF THE INVENTION
La problemática más importante que genera desgaste y reduce la vida de los transformadores de potencia tipo columnas está relacionada con su proceso de envejecimiento. El sistema aislante (papel y aceite) se degrada a través del tiempo, este proceso depende de las condiciones térmicas y eléctricas a las cuales es sometido, asi como factores tales como agua u oxigeno que puedan introducirse al sistema acelerando su proceso de envejecimiento. The most important problem that generates wear and reduces the life of column type power transformers is related to its aging process. The insulating system (paper and oil) degrades over time, this process depends on the thermal and electrical conditions to which it is subjected, as well as factors such as water or oxygen that can be introduced into the system accelerating its aging process.
La presencia de humedad en el interior del transformador influye en el deterioro de las propiedades dieléctricas del sistema aislante (papel/aceite) , además produce el envejecimiento acelerado del papel, y la emisión de burbujas de vapor de agua a elevadas temperaturas. Durante la operación del transformador, los cambios en la temperatura provocan la migración de humedad entre el papel y el aceite. Cuando se incrementa la temperatura dentro del transformador, la humedad migra del papel hacia el aceite y cuando la temperatura desciende, la humedad regresa al papel. The presence of moisture inside the transformer influences the deterioration of the dielectric properties of the insulating system (paper / oil), also produces accelerated paper aging, and the emission of water vapor bubbles at high temperatures. During the operation of the transformer, changes in temperature cause the migration of moisture between the paper and the oil. When the temperature inside the transformer increases, the humidity migrates from the paper to the oil and when the temperature drops, the humidity returns to the paper.
Este fenómeno modifica las propiedades dieléctricas del papel aislante y produce el envejecimiento acelerado del papel, aumentando el riesgo de condiciones de falla en el transformador.  This phenomenon modifies the dielectric properties of insulating paper and produces accelerated paper aging, increasing the risk of transformer failure conditions.
Cuando un trasformador es sometido a una sobrecarga, se produce un incremento en la temperatura del sistema aislante papel/aceite en un corto periodo de tiempo, la presencia de humedad en el papel provoca migración súbita de la humedad desde el papel hacia el aceite, con lo que la posibilidad de que se presente el fenómeno de generación de burbujas a causa de esta migración de humedad es muy alta.  When a transformer is subjected to an overload, there is an increase in the temperature of the paper / oil insulating system in a short period of time, the presence of moisture in the paper causes sudden migration of moisture from the paper to the oil, with The possibility of the phenomenon of bubble generation due to this moisture migration is very high.
La humedad del ambiente entra en los transformadores por fallas en los empaques o fugas. Un pequeño aumento en el porcentaje de humedad, reduce en gran medida la expectativa de vida del aislamiento, ya que al elevarse la temperatura y la presión durante una sobrecarga, esta humedad puede convertirse en burbujas de vapor de agua en el interior del transformador, debido a que la rigidez dieléctrica de los gases es mucho menor que la resistencia dieléctrica del aceite o el aislamiento de celulosa puede producirse una falla en el equipo y una reducción de vida de este. Por lo tanto, evaluar el contenido de humedad en el aislamiento y la temperatura de formación de burbujas es un factor fundamental para garantizar la fiabilidad y longevidad del transformador. Ambient moisture enters the transformers due to packaging failures or leaks. A small increase in the percentage of humidity greatly reduces the life expectancy of the insulation, since when the temperature and pressure rise during an overload, this humidity can become water vapor bubbles inside the transformer, due to because the dielectric strength of the gases is much less than the dielectric strength of the oil or the cellulose insulation, a failure in the equipment and a reduction in life of the equipment can occur. Therefore, assessing the moisture content in the insulation and the bubble formation temperature is a fundamental factor in ensuring the reliability and longevity of the transformer.
Actualmente los dispositivos desarrollados para determinar el contenido de la humedad en el papel aislante de las bobinas en trasformadores de potencia, están basados en métodos y técnicas de diagnóstico que solo permiten realizar esta estimación cuando el transformador esta fuera de operación (fuera de linea) . Currently the devices developed to determine the moisture content in the insulating paper of the Coils in power transformers, are based on diagnostic methods and techniques that only allow this estimate to be made when the transformer is out of operation (out of line).
De la misma manera/ si bien existen algunos dispositivos electrónicos capaces de determinar en linea el contenido de humedad en el papel y la temperatura de generación de burbujas en transformadores de potencia, dichos dispositivos utilizan modelos matemáticos que fueron desarrollados asumiendo que la humedad es uniforme en todo el transformador, lo cual no es representativo de la condición real de operación, ya que el fenómeno de migración de humedad es dependiente del perfil térmico axial.  In the same way / although there are some electronic devices capable of determining online the moisture content in the paper and the temperature of bubble generation in power transformers, these devices use mathematical models that were developed assuming that the humidity is uniform in The entire transformer, which is not representative of the actual operating condition, since the phenomenon of moisture migration is dependent on the axial thermal profile.
En este sentido la patente US 8, 149, 003 describe un sistema que permite determinar el contenido de humedad de un transformador, dicho sistema comprende las etapas de medir las propiedades dieléctricas y la temperatura de aislamiento dependiendo de la frecuencia de un voltaje el cual es aplicado al transformador; aplicar diferentes respuestas dieléctricas; y aplicar una fórmula mediante la cual se determinan respuestas dieléctricas y/o propiedades dieléctricas, no obstante está medición se realiza fuera de linea.  In this sense, US Patent 8, 149, 003 describes a system that allows determining the moisture content of a transformer, said system comprises the steps of measuring the dielectric properties and the insulation temperature depending on the frequency of a voltage which is applied to the transformer; apply different dielectric responses; and apply a formula by which dielectric responses and / or dielectric properties are determined, however this measurement is performed offline.
La patente US 7, 516, 651 se refiere a un método para determinar el contenido de agua de un aislante sólido en un lugar especifico dentro de un transformador, dicho método comprende determinar la temperatura de un aislante sólido, calcular la saturación de humedad relativa del aceite, calcular el último contenido de agua y calcular el contenido de agua reciente, dicha medición se realiza en linea.  US 7,516,651 refers to a method for determining the water content of a solid insulator in a specific place within a transformer, said method comprising determining the temperature of a solid insulator, calculating the relative humidity saturation of the oil, calculate the last water content and calculate the recent water content, said measurement is done online.
La patente OS 6, 779, 385 muestra un dispositivo para monitorear el contenido de humedad de un material dieléctrico sólido dentro de un recinto, dicho material sumergido en un fluido dieléctrico; el dispositivo comprende medios para medir la humedad, medios para medir la temperatura y medios de circuito electrónico para capturar los datos respecto al nivel de humedad, en este caso el cálculo se realiza con base a la variación de la solubilidad del agua respecto a la temperatura, la humedad en el aceite y la temperatura del aceite. Patent OS 6, 779, 385 shows a device for monitoring the moisture content of a solid dielectric material within an enclosure, said material immersed in a dielectric fluid; the device comprises means for measuring humidity, means for measuring temperature and electronic circuit means for capturing data regarding the level of humidity, in this case the calculation is made based on the variation of the solubility of the water with respect to the temperature, the humidity in the oil and the temperature of the oil.
La solicitud internacional WO/2007/038845 describe un sistema para medir y monitorear la cantidad de humedad de aceite aislante en transformadores, dicho sistema comprende un módulo sensor que está en contacto con el aceite y una interfaz del módulo, ios cuales permiten la medición y monitoreo de humedad en el aceite, el sistema permite programar valores limites de manera que cuando estos son rebasados se active una serie de alarmas, la medición se realiza en linea.  The international application WO / 2007/038845 describes a system for measuring and monitoring the amount of moisture of insulating oil in transformers, said system comprises a sensor module that is in contact with the oil and an interface of the module, which allow the measurement and Oil moisture monitoring, the system allows you to program limit values so that when these are exceeded a series of alarms is activated, the measurement is done online.
La patente EP 2, 348, 307 se refiere a un dispositivo y método para diagnósticos en línea y el control del comportamiento dieléctrico de transformadores utilizando un lector en línea de la humedad relativa del aceite y su temperatura, lo cual determina la fuerza dieléctrica del aceite lo que permite un cambio del régimen operacionai de un transformador para prevenir efectivamente cualquier decremento de la fuerza dieléctrica del aceite por debajo de los límites requeridos por la norma.  EP 2, 348, 307 refers to a device and method for in-line diagnostics and control of the dielectric behavior of transformers using an online reader of the relative humidity of the oil and its temperature, which determines the dielectric strength of the oil which allows a change in the operating regime of a transformer to effectively prevent any decrease in the dielectric strength of the oil below the limits required by the standard.
SUMARIO DE LE INVENCIÓN SUMMARY OF THE INVENTION
Por lo tanto, un objetivo de la presente invención es brindar un dispositivo electrónico para determinar la capacidad de sostener con seguridad las condiciones de sobrecarga temporal y su tiempo de aplicación en un transformador de potencia, además de un diagnóstico oportuno para la prevención de fallas ya que determina el contenido de humedad en papel aislante de las bobinas, sin necesidad de sacar el trasformador de operación, así como la temperatura de generación de burbujas, lo que minimiza el riesgo de un posible daño catastrófico del equipo. Therefore, an objective of the present invention is to provide an electronic device to determine the ability to safely hold the temporary overload conditions and their application time in a power transformer, in addition to a timely diagnosis for the prevention of failures already which determines the moisture content in insulating paper of the coils, without the need to take out the operating transformer, as well as the temperature of bubble generation, which minimizes the risk of a Possible catastrophic damage to the equipment.
Es un objetivo más de la presente invención, brindar un dispositivo electrónico con la capacidad de estimar en tiempo real, el contenido de humedad en el papel aislante y la distribución axial de la humedad en el papel, en 4 zonas térmicas distribuidas equidistantemente en la altura del devanado, esto es realizado con base a un modelo matemático desarrollado experimentalmente en función de un perfil térmico, parámetros de diseño y condiciones de operación en linea, además el modelo también toma en consideración el envejecimiento del sistema aislante papel-aceite, por lo que la estimación de dinámica de la migración de humedad es más precisa que las curvas de equilibrio estático que utilizan los modelos convencionales. It is a further objective of the present invention, to provide an electronic device with the ability to estimate in real time, the moisture content in the insulating paper and the axial distribution of the moisture in the paper, in 4 thermal zones distributed equally in height of the winding, this is done based on a mathematical model developed experimentally based on a thermal profile, design parameters and operating conditions in line, in addition the model also takes into account the aging of the paper-oil insulating system, so The estimation of moisture migration dynamics is more accurate than the static equilibrium curves used by conventional models.
Asimismo, un objetivo más de la presente invención es brindar un dispositivo electrónico que utiliza un segundo modelo matemático mediante el cual, con el resultado del porcentaje de humedad determinado por el modelo anterior, puede estimar el limite de tiempo en el que un transformador puede ser sometido a una sobrecarga antes de que éste sobrepase el umbral de temperatura de generación de burbujas de vapor de agua. Likewise, a further objective of the present invention is to provide an electronic device that uses a second mathematical model by means of which, with the result of the percentage of humidity determined by the previous model, it can estimate the time limit in which a transformer can be subjected to an overload before it exceeds the temperature threshold for generating water vapor bubbles.
De igual forma, es un objetivo más de la presente invención brindar un dispositivo electrónico que utiliza un tercer modelo matemático basado en la norma C.57.91-1995 con el cual es posible estimar la temperatura máxima del Hot spot que será alcanzada durante el tiempo de aplicación de la sobrecarga y el porcentaje de pérdida de vida que sufrirá el equipo, debido al incremento de la temperatura durante este periodo. Similarly, it is a further objective of the present invention to provide an electronic device that uses a third mathematical model based on the C.57.91-1995 standard with which it is possible to estimate the maximum Hot spot temperature that will be reached during the time of application of the overload and the percentage of loss of life that the equipment will suffer, due to the increase in temperature during this period.
Es además un objetivo de la presente invención, brindar un dispositivo electrónico el cual comprende 2 microcontroladores principales, en donde uno de ellos realiza la función de unidad de procesamiento en el cual se encuentran implementados los modelos matemáticos con los que se realizan los cálculos para la estimación del porcentaje del contenido de humedad en el papel asi como la distribución de humedad en la altura axial de las bobinas, además del cálculo de la temperatura de generación de burbujas y la estimación de la pérdida de vida gracias a la máxima temperatura de Hot Spot la cual también se calcula en la unidad de procesamiento; el otro, lleva a cabo exclusivamente procesos de comunicación, protocolos y almacenamiento en memoria. It is also an objective of the present invention to provide a electronic device which comprises 2 main microcontrollers, where one of them performs the function of processing unit in which the mathematical models with which calculations are made to estimate the percentage of moisture content in the paper are implemented. such as the distribution of humidity in the axial height of the coils, in addition to the calculation of the bubble generation temperature and the estimation of the loss of life thanks to the maximum Hot Spot temperature which is also calculated in the processing unit; the other, exclusively carries out communication processes, protocols and storage in memory.
Más aún, un objetivo de la presente invención es brindar un dispositivo electrónico que utiliza una interfaz gráfica en donde se puede evaluar el tiempo máximo de sobrecarga aplicada a un transformador de potencia, sin que éste exceda la temperatura donde iniciará la generación de burbujas de vapor de agua a causa del contenido de humedad en el papel aislante de las bobinas, asi como estimar el porcentaje de perdida de vida y la temperatura máxima de hot spot alcanzada en la sobrecarga. Moreover, an objective of the present invention is to provide an electronic device that uses a graphical interface where the maximum overload time applied to a power transformer can be evaluated, without exceeding the temperature where the generation of steam bubbles will begin of water due to the moisture content in the insulating paper of the coils, as well as estimating the percentage of loss of life and the maximum hot spot temperature reached in the overload.
BREVE DESCRIPCIÓN DE LAS FIGURAS DE LA INVENCION BRIEF DESCRIPTION OF THE FIGURES OF THE INVENTION
La Figura 1 se refiere a las variables introducidas en tiempo real al microcontrolador a través de señales analógicas. La Figura 2 muestra un diagrama a bloques del diseño conceptual electrónico del dispositivo Figure 1 refers to the variables introduced in real time to the microcontroller through analog signals. Figure 2 shows a block diagram of the electronic conceptual design of the device
La Figura 3 muestra un diagrama de bloques que indica la secuencia lógica que sigue el microcontrolador para ejecutar los algoritmos matemáticos de los modelos. La Figura 4 muestra un diagrama de bloques respecto a las variables de entrada que utiliza el modelo matemático para calcular la temperatura máxima de hot spot y el porcentaje de perdida de vida del transformador. Figure 3 shows a block diagram that indicates the logical sequence that the microcontroller follows to execute the mathematical algorithms of the models. Figure 4 shows a block diagram with respect to the input variables used by the mathematical model to calculate the maximum hot spot temperature and the percentage of life loss of the transformer.
La Figura 5 muestra un diagrama de bloques respecto a las variables de entrada al algoritmo matemático y el diagrama de flujo que ejecuta el microcontrolador para calcular el porcentaje de humedad en el papel de las bobinas y la humedad en el papel en 4 zonas térmicas distribuidas equidistantemente en la altura del devanado. Figure 5 shows a block diagram with respect to the input variables to the mathematical algorithm and the flow chart executed by the microcontroller to calculate the percentage of paper humidity of the coils and the humidity in the paper in 4 thermal zones distributed equidistantly at the height of the winding.
La Figura 6 muestra las variables de entrada del modelo matemático que estima la temperatura de generación de burbujas asi como el diagrama a bloques del proceso de ejecución de las instrucciones programadas en el microcontrolador Figure 6 shows the input variables of the mathematical model that estimates the bubble generation temperature as well as the block diagram of the execution process of the instructions programmed in the microcontroller
DESCRIPCION DETALLADA DE LA INVENCION DETAILED DESCRIPTION OF THE INVENTION
La presente invención se refiere a un dispositivo electrónico diseñado para determinar en linea, el contenido de humedad en el papel del devanado y la distribución de humedad en el papel en 4 zonas térmicas distribuidas equidistantemente en la altura del devanado de un transformador de potencia tipo columnas. Además el dispositivo tiene la capacidad de estimar en linea, la temperatura de generación de burbujas de vapor de agua, la temperatura máxima de hot spot y el porcentaje de pérdida de vida en las condiciones a las cuales este está operando el transformador. The present invention relates to an electronic device designed to determine in line, the moisture content in the paper of the winding and the distribution of moisture in the paper in 4 thermal zones distributed equally in the height of the winding of a power transformer type columns . In addition, the device has the ability to estimate in line, the temperature of the generation of water vapor bubbles, the maximum hot spot temperature and the percentage of loss of life in the conditions under which the transformer is operating.
El dispositivo electrónico de la presente invención utiliza una interfaz gráfica que permite evaluar el tiempo seguro de operación, en el cual un transformador de potencia, preferentemente tipo columnas, puede ser sometido a una sobrecarga, sin que se presente el riesgo de generación de burbujas de vapor de agua en el interior del transformador.The electronic device of the present invention uses a graphical interface that allows to evaluate the safe operating time, in which a power transformer, preferably columns type, can be subjected to an overload, without the risk of generating Water vapor bubbles inside the transformer.
En el contexto de la presente invención, el dispositivo se limita a transformadores tipo columnas. De acuerdo con la presente invención, el dispositivo electrónico adquiere cuatro señales analógicas de entrada las cuales son enviadas a un módulo de acondicionamiento para ser procesadas para su conversión digital; la primera señal es para la temperatura del aceite, que es tomada por un indicador de temperatura (1) instalado en la parte superior del transformador, el cual envia la medición al módulo de entrada del dispositivo a través de una señal de 4-20 mA; la segunda entrada se utiliza para medir el contenido de humedad del aceite utilizando un dispositivo especializado para determinar la humedad (2) en el aceite en ppm, el resultado de la medición es enviado al módulo de entrada por una señal de 4-20 mA; la tercera entrada analógica es utilizada para recopilar los valores de la corriente de carga del transformador, para lo que se usa un transformador de corriente tipo core (3), con el que se mide la corriente en la linea de uno de los transformadores de corriente instalados en el transformador, esta medición es enviada a través de una señal analógica de 4-20 mA al módulo de entrada; la cuarta entrada del módulo analógico es utilizada para la adquisición del valor de temperatura ambiente, la cual es medida con un detector de temperatura resistivo (RTD) (4). La Figura 1 muestra los sensores instalados en el transformador para realizar la medición en linea. In the context of the present invention, the device is limited to column type transformers. In accordance with the present invention, the electronic device acquires four analog input signals which are sent to a conditioning module to be processed for digital conversion; The first signal is for the oil temperature, which is taken by a temperature indicator (1) installed on the top of the transformer, which sends the measurement to the input module of the device through a 4-20 mA signal ; the second input is used to measure the moisture content of the oil using a specialized device to determine the humidity (2) in the oil in ppm, the measurement result is sent to the input module by a 4-20 mA signal; The third analog input is used to collect the values of the transformer load current, for which a core type current transformer (3) is used, with which the current in the line of one of the current transformers is measured installed in the transformer, this measurement is sent via an analog 4-20 mA signal to the input module; The fourth input of the analog module is used for the acquisition of the ambient temperature value, which is measured with a resistive temperature detector (RTD) (4). Figure 1 shows the sensors installed in the transformer for online measurement.
Una vez recolectadas las señales analógicas en el módulo de entrada estas son enviadas al módulo de acondicionamiento para ser acondicionadas y posteriormente transmitidas al módulo de conversión en donde se realizara el cambio de señales analógicas a digitales, estas son enviadas de forma digital a un microcontrolador el cual funciona como unidad de procesamiento, en donde se encuentran implementados los tres modelos matemáticos que realizan el diagnostico en linea, el microcontrolador es el encargado de ejecutar los algoritmos de los modelos e interpretar las instrucciones contenidas en el programa y procesar los datos, asimismo el dispositivo cuenta con otro raicrocontrolador que cumple funciones exclusivamente de procesos de comunicación, manejo de protocolos y almacenamiento en memoria, el dispositivo electrónico también tiene una unidad dedicada al almacenamiento de la información, la Figura 2 muestra el diseño electrónico conceptual de la presente invención. Once the analog signals have been collected in the input module, they are sent to the conditioning module to be conditioned and subsequently transmitted to the conversion module where the analog to digital signals will be changed, these are sent digitally to a microcontroller. which works as a processing unit, where the three mathematical models that carry out the online diagnosis are implemented, the The microcontroller is in charge of executing the algorithms of the models and interpreting the instructions contained in the program and processing the data, the device also has another raro-controller that performs functions exclusively of communication processes, protocol management and memory storage, the device Electronic also has a unit dedicated to the storage of information, Figure 2 shows the conceptual electronic design of the present invention.
El microcontrolador de la unidad de procesamiento utiliza variables medidas en tiempo real y enviadas al dispositivo electrónico de manera analógica, la Figura 1 muestra la instalación de los instrumentos que realizan la medición en linea de las variables analógicas utilizadas por los algoritmos matemáticos programados en el microcontrolador principal.  The microcontroller of the processing unit uses variables measured in real time and sent to the electronic device in an analog way, Figure 1 shows the installation of the instruments that perform the online measurement of the analog variables used by the mathematical algorithms programmed in the microcontroller principal.
De esta forma, las señales analógicas son convertidas de manera digital para ser utilizadas por el algoritmo matemático programado en el microcontrolador, la ejecución de los modelos se realiza en tres etapas, la Figura 3 muestra la secuencia que sigue el microcontrolador para correr los modelos, primero se ejecuta el modelo térmico que estima la temperatura máxima de hot spot que será alcanzada durante un determinado periodo de tiempo, después se corre el modelo para determinar el contenido de humedad en el papel, los resultados de este cálculo de humedad son utilizados por el modelo de temperatura de generación de burbujas, que es el último modelo en ejecutarse, una vez ejecutados los tres modelos, el microcontrolador tiene implementada la programación necesaria para realizar la evaluación de la temperatura de hot spot máxima y la temperatura de generación de burbujas con lo que evaluara el periodo de tiempo en el cual no existirá riesgo de generación de burbujas y el porcentaje de perdida de vida del transformador.  In this way, the analog signals are digitally converted to be used by the mathematical algorithm programmed in the microcontroller, the execution of the models is done in three stages, Figure 3 shows the sequence that the microcontroller follows to run the models, First the thermal model that estimates the maximum hot spot temperature that will be reached during a certain period of time is executed, then the model is run to determine the moisture content in the paper, the results of this moisture calculation are used by the bubble generation temperature model, which is the last model to be executed, once the three models have been executed, the microcontroller has implemented the necessary programming to perform the evaluation of the maximum hot spot temperature and the bubble generation temperature with that will evaluate the period of time in which there will be no risk of bubble generation and l percentage of transformer life loss.
El primer modelo que se corre está basado en el estándar de IEEE C57.91-1995 éste calcula la temperatura de hot spot máxima que se alcanzará en una sobrecarga y el porcentaje de perdida de vida del transformador debido a la temperatura, el microcontrolador utiliza los parámetros de diseño mecánico, eléctrico y térmico programados previamente en el dispositivo y los datos acondicionados y convertidos de forma digital que fueron tomados por los sensores instalados en el transformador para realizar el diagnostico en linea, la Figura 4 muestra un diagrama de bloques del proceso que sigue el microcontrolador para realizar la ejecución del modelo de cálculo de hot spot y porcentaje de perdida de vida, después de ejecutar el modelo anterior el microcontrolador corre el algoritmo para estimar el porcentaje de humedad contenida en el papel de las bobinas, para efectuar este cálculo el modelo utiliza el parámetro programado fuera de linea de la acidez en el aceite y los valores digitales de las variables medidas en linea del contenido de humedad en el aceite y la temperatura del aceitería Figura 5 muestra las variables que utiliza el microcontrolador para ejecutar el modelo matemático que determina el porcentaje de contenido de humedad en el papel y la distribución de humedad a lo largo del devanado, cabe destacar que el algoritmo matemático para determinar la humedad en el papel fue desarrollado recreando el fenómeno de migración de humedad que ocurre en el interior del transformador, utilizando un set experimental en el cual se reprodujo el perfil térmico axial de las bobinas. The first model that is run is based on the standard of IEEE C57.91-1995 this calculates the maximum hot spot temperature that will be reached in an overload and the percentage of life loss of the transformer due to the temperature, the microcontroller uses the parameters of mechanical, electrical and thermal design previously programmed in the device and the digitally conditioned and converted data that were taken by the sensors installed in the transformer to perform the online diagnosis, Figure 4 shows a block diagram of the process that the microcontroller follows to perform the calculation model execution of hot spot and percentage of loss of life, after executing the previous model the microcontroller runs the algorithm to estimate the percentage of moisture contained in the paper of the coils, to perform this calculation the model uses the parameter programmed offline of the acidity in the oil and the digital values of the variables measured in line of the content of humidity in the oil and the temperature of the oil industry Figure 5 shows the variables that the microcontroller uses to execute the mathematical model that determines the percentage of moisture content in the paper and the distribution of moisture throughout the winding, it should be noted that the algorithm Mathematical to determine the humidity in the paper was developed by recreating the phenomenon of moisture migration that occurs inside the transformer, using an experimental set in which the axial thermal profile of the coils was reproduced.
Después realizar el cálculo del porcentaje de humedad en el papel por el segundo modelo, este resultado será utilizado como dato de entrada del tercer modelo matemático para estimar la temperatura de generación de burbujas de vapor de agua, el algoritmo también utiliza los valores digitales tomados en linea del sensor de temperatura del aceite (1) , la temperatura ambiente (4) y el porcentaje de carga (3), asi como los datos programados en el microcontrolador de la presión atmosférica y el grado de polimerización, la Figura 6 muestra el diagrama a bloques del proceso de ejecución del modelo y las variables de entrada para realizar la estimación de la temperatura de generación de burbujas. Una vez que son ejecutados los modelos de diagnóstico en la unidad de procesamiento central estos son enviados al microcontrolador dedicado a la transmisión de información. El almacenamiento de la información se realiza en primer estancia en la computadora que tiene instalada la interfaz, adicionalmente el dispositivo cuenta con una unidad de almacenamiento de información hasta 3 meses . After calculating the percentage of moisture in the paper by the second model, this result will be used as input of the third mathematical model to estimate the temperature of water vapor bubble generation, the algorithm also uses the digital values taken in line of the oil temperature sensor (1), the ambient temperature (4) and the percentage of load (3), as well as the data programmed in the microcontroller of the atmospheric pressure and the degree of polymerization, Figure 6 It shows the block diagram of the model execution process and the input variables for estimating the bubble generation temperature. Once the diagnostic models are executed in the central processing unit, they are sent to the microcontroller dedicated to the transmission of information. The storage of the information is done in the first stay on the computer that has the interface installed, in addition the device has an information storage unit up to 3 months.
De acuerdo con la presente invención, la interfaz gráfica permitirá al usuario evaluar en linea si el transformador está en condiciones de aceptar una sobrecarga, La interfaz gráfica utiliza tres tipos de datos de entrada para poder ejecutar los algoritmos matemáticos, los primeros son los valores fijos, que son los parámetros del diseño mecánico, eléctrico y térmico especificos del transformador, estos valores no cambiaran una vez programados en el software, los segundos son ios valores reprogramables que son los parámetros de la condición del sistema aislante papel-aceite, estos valores son obtenidos a través de pruebas fisicoquímicas del aceite y deben ser actualizados en la programación periódicamente, los terceros son los valores en linea, estos parámetros determinan la condición actual de operación del transformador, y son obtenidos mediante los sensores instalados en el transformador que miden en tiempo real los parámetros de temperatura del aceite, temperatura ambiente, carga del transformador y el porcentaje de humedad en el aceite, estos valores estarán cambiando en el tiempo de acuerdo a la operación del transformador. In accordance with the present invention, the graphical interface will allow the user to evaluate online if the transformer is in a position to accept an overload. The graphical interface uses three types of input data to be able to execute the mathematical algorithms, the first are the fixed values , which are the parameters of the specific mechanical, electrical and thermal design of the transformer, these values will not change once programmed in the software, the seconds are the reprogrammable values that are the parameters of the condition of the paper-oil insulating system, these values are obtained through physicochemical tests of the oil and must be periodically updated in the programming, the third parties are the online values, these parameters determine the current operating condition of the transformer, and are obtained by means of the sensors installed in the transformer that measure in time actual oil temperature parameters, temperature ura environment, transformer load and the percentage of moisture in the oil, these values will be changing over time according to the operation of the transformer.
La interfaz utiliza todos los parámetros de entrada para estimar en linea; el contenido de humedad en el papel de las bobinas, la distribución de humedad en el papel a lo largo de la altura axial del devanado, la temperatura de generación de burbujas de vapor de agua, la temperatura máxima de hot spot y la pérdida de vida en las condiciones actuales a cuales esta operado el transformador. Adicionalmente la interfaz gráfica cuenta con un módulo para estimar fuera de linea la evolución de la generación de burbujas de vapor de agua cuando un transformador de potencia es sometido a una sobrecarga temporal, el software utiliza como valores de entrada, el nivel de sobrecarga, el tiempo de aplicación de la sobrecarga, la humedad en el papel, la temperatura del aceite, la temperatura ambiente y la presión atmosférica, con estos parámetros la interfaz gráfica puede estimar el tiempo máximo al cual podrá ser sometido un transformador a una sobrecarga, sin que se presente el riesgo de generación de burbujas de vapor de agua en el interior, además el software permitirá conocer la temperatura máxima de hot spot a la cual estará sometido el transformador durante la sobrecarga temporal y su consecuente pérdida de vida por la temperatura de hot spot alcanzada durante la sobrecarga. La interfaz también puede estimar fuera de linea el contenido de humedad en el devanado del transformador, para realizar el cálculo deberán ser introducidas las variables de entrada de humedad en el aceite, acidez en al aceite y temperatura del aceite, con estos tres parámetros de entrada el software determina el porcentaje de humedad en el papel de las bobinas y la distribución axial de la humedad en el papel, en 4 zonas térmicas distribuidas equidistantemente en la altura del devanado. El software permite conocer en linea las condiciones de humedad del papel aislante sin necesidad de sacar el transformador de operación. The interface uses all input parameters to estimate online; the moisture content in the paper of the coils, the distribution of moisture in the paper along the axial height of the winding, the generation temperature of water vapor bubbles, the maximum hot spot temperature and loss of life in the current conditions under which the transformer is operated. Additionally, the graphical interface has a module to estimate offline the evolution of the generation of water vapor bubbles when a power transformer is subjected to a temporary overload, the software uses as input values, the level of overload, the time of application of the overload, the humidity in the paper, the temperature of the oil, the ambient temperature and the atmospheric pressure, with these parameters the graphical interface can estimate the maximum time to which a transformer can be subjected to an overload, without the risk of generating water vapor bubbles inside is presented, in addition the software will allow to know the maximum hot spot temperature to which the transformer will be subjected during the temporary overload and its consequent loss of life due to the hot spot temperature reached during overload. The interface can also estimate the moisture content in the transformer winding off-line, in order to perform the calculation the humidity input variables in the oil, acidity in the oil and oil temperature must be entered, with these three input parameters The software determines the percentage of humidity in the paper of the reels and the axial distribution of the humidity in the paper, in 4 thermal zones distributed equally in the height of the winding. The software allows to know online the humidity conditions of the insulating paper without the need to remove the operating transformer.
Adicionalmente la interfaz gráfica cuenta con indicadores numéricos y gráficos de las salidas del dispositivo, indicadores numéricos y gráficos de valores históricos de las salidas del dispositivo, configuración operando en modo de comunicación Ethernet TCP/IP y RS-232, sin embargo es posible utilizar un adaptador para una comunicación Modbus o DNP.3. El software fue desarrollado para monitoreo de hasta 32 dispositivos conectados a la misma red Ethernet donde está operando el equipo, el software cuenta con una módulo donde se asigna la dirección IP a la cual está conectado otro dispositivo electrónico, una vez programada la dirección IP del otro dispositivo el software automáticamente puede mostrar en la pantalla principal los resultados del diagnóstico en línea de los transformadores agregados. El software tiene dos modos de operación una para permitir al usuario monitorear y otro para configurar (Hardware) . El modo de monitoreo trae la información almacenada en el dispositivo electrónico a la PC de usuario y despliega los resultados del cálculo de ios modelos y el modo de configuración envía la información de configuración al dispositivo y los parámetros fuera de linea que serán programados en la unidad de procesamiento central del dispositivo para efectuar los cálculos de los algoritmos matemáticos. Additionally, the graphical interface has numerical indicators and graphs of the device's outputs, numerical indicators and graphs of historical values of the device's outputs, configuration operating in the mode of Ethernet TCP / IP and RS-232 communication, however it is possible to use an adapter for a Modbus or DNP communication.3. The software was developed for monitoring up to 32 devices connected to the same Ethernet network where the equipment is operating, the software has a module where the IP address to which another electronic device is connected is assigned, once the IP address of the device is programmed another device the software can automatically display on the main screen the results of the online diagnosis of the added transformers. The software has two modes of operation one to allow the user to monitor and another to configure (Hardware). The monitoring mode brings the information stored in the electronic device to the user PC and displays the results of the calculation of the models and the configuration mode sends the configuration information to the device and the offline parameters that will be programmed in the unit of central processing of the device to perform the calculations of the mathematical algorithms.
La herramienta computacional cuenta con un módulo adicional que permite realizar estimaciones del porcentaje de sobrecarga y el tiempo aplicación, al que puede ser sometido a un transformador en operación, sin que éste presente riesgo de generación de burbujas de vapor de agua, la interfaz también determina la temperatura máxima de hot spot que se presentara a causa de la sobrecarga y el porcentaje de perdida de vida del transformador a consecuencia de la misma.  The computational tool has an additional module that allows estimations of the percentage of overload and the application time, to which it can be subjected to a transformer in operation, without this presenting a risk of generating water vapor bubbles, the interface also determines the maximum hot spot temperature that will occur due to the overload and the percentage of life loss of the transformer as a result of it.

Claims

REIVINDICACIONES Habiéndose descrito la invención, se reclama como propiedad lo contenido en las siguientes reivindicaciones: CLAIMS Having described the invention, the content of the following claims is claimed as property:
1. - Un dispositivo electrónico caracterizado porque permite monitorear y determinar en línea la humedad en el sistema aislante papel-aceite del devanado de un transformador de potencia, la distribución de humedad en el papel en cuatro zonas térmicas distribuidas equidistantemente en la altura del devanado y diagnosticar el tiempo seguro de operación en el cual el transformador puede ser sometido a una sobrecarga sin que se presente el riesgo de generación de burbujas de vapor de agua en el interior del mismo; y porque 1. - An electronic device characterized in that it allows to monitor and determine online the humidity in the paper-oil insulating system of the winding of a power transformer, the distribution of moisture in the paper in four thermal zones distributed equally in the height of the winding and diagnose the safe operating time in which the transformer can be subjected to an overload without the risk of generating water vapor bubbles inside it; and because
comprende un primer módulo, de entrada el cual recibe cuatro señales analógicas de entrada,  It comprises a first input module which receives four analog input signals,
un segundo módulo, de acondicionamiento que acondiciona las cuatro señales analógicas de entrada,  a second conditioning module that conditions the four analog input signals,
un tercer módulo de conversión que realiza el cambio de señales analógicas a digitales,  a third conversion module that changes analog to digital signals,
un primer microcontroiador el cual es una unidad de procesamiento que utiliza una serie de tres modelos matemáticos obtenidos de forma experimental semejando las condiciones térmicas y dimensionales de un transformador de potencia, logrando una estimación dinámica de la migración de la humedad, más preciso que las curvas de equilibrio estático, para diagnóstico en linea,  a first microcontroller which is a processing unit that uses a series of three mathematical models obtained experimentally resembling the thermal and dimensional conditions of a power transformer, achieving a dynamic estimate of moisture migration, more accurate than curves of static equilibrium, for online diagnosis,
un segundo microcontroiador que realiza funciones exclusivas de comunicación, manejo de protocolos y almacenamiento en memoria, y  a second microcontroller that performs exclusive functions of communication, protocol management and memory storage, and
una unidad de almacenamiento de información.  A storage unit.
2. ~ El dispositivo electrónico de acuerdo con la reivindicación 1, en donde la primera señal analógica corresponde a los valores de temperatura del aceite, los cuales son medidos por un indicador de temperatura (1) instalado en la parte superior del transformador, que además envia la medición al módulo de entrada a través de una señal de 4 a 20 mA. 2. The electronic device according to claim 1, wherein the first analog signal corresponds to the oil temperature values, the which are measured by a temperature indicator (1) installed on the top of the transformer, which also sends the measurement to the input module through a 4 to 20 mA signal.
3. - El dispositivo electrónico de acuerdo con la reivindicación 1, en donde la segunda señal analógica corresponde a los valores de humedad del aceite, los cuales son medidos por un dispositivo especializado para determinar la humedad (2) en el aceite en ppm, que además envía la medición al módulo de entrada por una señal de 4-20 mA. 3. - The electronic device according to claim 1, wherein the second analog signal corresponds to the oil moisture values, which are measured by a specialized device to determine the humidity (2) in the oil in ppm, which It also sends the measurement to the input module by a 4-20 mA signal.
4. - El dispositivo electrónico de acuerdo con la reivindicación 1, en donde la tercera señal analógica corresponde a la recopilación de los valores de la corriente de carga del transformador mediante un transformador de corriente tipo core (3), con el que se mide la corriente en la línea de uno de los transformadores de corriente instalados en el transformador, dichos valores son enviados a través de una señal de 4-20 mA. 4. - The electronic device according to claim 1, wherein the third analog signal corresponds to the collection of the values of the transformer load current by means of a core type current transformer (3), with which the current in the line of one of the current transformers installed in the transformer, these values are sent through a 4-20 mA signal.
5. - El dispositivo electrónico de acuerdo con la reivindicación 1, en donde la cuarta señal analógica corresponde a los valores de temperatura ambiente, los cuales son medidos con un detector de temperatura resistivo (4). 5. - The electronic device according to claim 1, wherein the fourth analog signal corresponds to the ambient temperature values, which are measured with a resistive temperature detector (4).
6. - El dispositivo electrónico de acuerdo con la reivindicación 1, en donde el primer microcontrolador comprende tres modelos de diagnóstico en línea, dicho primer microcontrolador ejecuta los algoritmos de los modelos, interpreta las instrucciones y procesa los datos utilizando variables medidas en tiempo real y enviadas al dispositivo electrónico (1) de manera analógica. 6. - The electronic device according to claim 1, wherein the first microcontroller comprises three online diagnostic models, said first microcontroller executes the algorithms of the models, interprets the instructions and processes the data using variables measured in real time and sent to the electronic device (1) in an analog way.
7.- El dispositivo electrónico de acuerdo con la reivindicación 6, en donde el primer modelo de diagnóstico calcula la temperatura de hot spot máxima que se alcanzará en una sobrecarga y el porcentaje de pérdida de vida del transformador debido a la temperatura, utilizando los parámetros de diseño mecánico, eléctrico y térmico programados previamente en el dispositivo electrónico (1) y utilizando los datos acondicionados y convertidos que fueron tomados por los sensores instalados en el transformador. 7.- The electronic device according to the claim 6, wherein the first diagnostic model calculates the maximum hot spot temperature that will be reached in an overload and the percentage of transformer life loss due to the temperature, using the mechanical, electrical and thermal design parameters previously programmed in the electronic device (1) and using the conditioned and converted data that were taken by the sensors installed in the transformer.
8.- El dispositivo electrónico de acuerdo con la reivindicación 6, en donde posterior al primer modelo de diagnóstico, el primer microcontrolador corre el segundo modelo de diagnóstico el cual calcula el porcentaje de humedad contenida en el papel de las bobinas y la distribución de humedad a lo largo del devanado, utilizando el parámetro programado de la acidez en el aceite y los valores digitales de las variables medidas en linea del contenido de humedad en el aceite y la temperatura de aceite. 8. The electronic device according to claim 6, wherein after the first diagnostic model, the first microcontroller runs the second diagnostic model which calculates the percentage of moisture contained in the paper of the coils and the humidity distribution throughout the winding, using the programmed parameter of the acidity in the oil and the digital values of the variables measured in line of the moisture content in the oil and the oil temperature.
9.- El dispositivo de electrónico de acuerdo con la reivindicación 6, en donde el tercer modelo de diagnóstico utiliza el resultado obtenido por el segundo modelo de diagnóstico como dato de entrada para estimar la temperatura de generación de burbujas de vapor de agua, además utiliza los valores digitales tomados en linea del sensor de temperatura del aceite, la temperatura ambiente y el porcentaje de carga, y los datos programados en el primer microcontrolador de la presión atmosférica y el grado de polimerización. 9. The electronic device according to claim 6, wherein the third diagnostic model uses the result obtained by the second diagnostic model as input to estimate the temperature of water vapor bubble generation, also uses the digital values taken in line of the oil temperature sensor, the ambient temperature and the percentage of load, and the data programmed in the first microcontroller of the atmospheric pressure and the degree of polymerization.
10.- El dispositivo electrónico de acuerdo con la reivindicación 1, en donde el dispositivo utiliza además una interfaz gráfica de forma externa la cual permite al usuario evaluar en linea si el transformador está en condiciones de aceptar una sobrecarga; 10. The electronic device according to claim 1, wherein the device also uses an external graphic interface which allows the user to evaluate online if the transformer is in a position to accept an overload;
en donde la interfaz gráfica utiliza tres tipos de datos de entrada para poder ejecutar e interpretar los modelos de diagnóstico, where the graphical interface uses three types of data input to run and interpret diagnostic models,
dichos datos comprenden en primer lugar valores fijos que corresponden a los parámetros del diseño mecánico, eléctrico y térmico específicos del transformador, los cuales permanecen sin cambios una vez programados,  These data first include fixed values that correspond to the specific mechanical, electrical and thermal design parameters of the transformer, which remain unchanged once programmed,
en segundo lugar los datos comprenden los valores reprogramables que son los parámetros de la condición del sistema aislante papel-aceite, los cuales deben ser actualizados periódicamente,  secondly, the data includes the reprogrammable values that are the parameters of the condition of the paper-oil insulating system, which must be updated periodically,
en tercer lugar los datos comprenden los valores en línea, que determinan la condición actual de operación del transformador y que son obtenidos mediante los sensores instalados en el transformador que miden en tiempo real los parámetros de temperatura del aceite, temperatura ambiente, carga del transformador y el porcentaje de humedad en el aceite, dichos valores cambiarán de acuerdo a la operación del transformador;  Thirdly, the data includes the values in line, which determine the current operating condition of the transformer and are obtained by means of the sensors installed in the transformer that measure in real time the parameters of oil temperature, ambient temperature, transformer load and the percentage of moisture in the oil, these values will change according to the operation of the transformer;
en donde la interfaz gráfica comprende además un módulo para estimar fuera de línea la evolución de la generación de burbujas de vapor de agua cuando un transformador de potencia es sometido a una sobrecarga temporal utilizando los valores de entrada, el nivel de sobrecarga, el tiempo de aplicación de la sobrecarga, la humedad en el papel, la temperatura del aceite, la temperatura ambiente y la presión atmosférica; y  where the graphical interface further comprises a module for estimating offline the evolution of water vapor bubble generation when a power transformer is subjected to a temporary overload using the input values, the overload level, the time of application of overload, moisture on paper, oil temperature, ambient temperature and atmospheric pressure; Y
en donde la interfaz gráfica comprende indicadores numéricos y gráficos de las salidas del dispositivo, indicadores numéricos y gráficos de valores históricos de las salidas del dispositivo, y una configuración operando en modo de medios de comunicación.  wherein the graphical interface comprises numerical indicators and graphs of the outputs of the device, numerical indicators and graphs of historical values of the outputs of the device, and a configuration operating in media mode.
11.- El dispositivo electrónico de acuerdo con la reivindicación 10, en donde los medios de comunicación pueden ser Ethernet TCP/IP y RS-232 o comunicación Modbus o DNP 3. 11. The electronic device according to claim 10, wherein the communication means can be Ethernet TCP / IP and RS-232 or Modbus or DNP 3 communication.
12. - Un proceso caracterizado porque permite monitorear y determinar en linea la humedad en el sistema aislante papel- aceite del devanado de un transformador de potencia, la distribución de humedad en el papel en cuatro zonas térmicas distribuidas equidistantemente en la altura del devanado y diagnosticar el tiempo seguro de operación en el cual el transformador puede ser sometido a una sobrecarga sin que se presente el riesgo de generación de burbujas de vapor de agua en el interior del mismo, utilizando el dispositivo electrónico (1) de acuerdo con las reivindicaciones 1 a 11; y porque comprende las etapas de: 12. - A process characterized in that it allows monitoring and determining in line the humidity in the paper-oil insulating system of the winding of a power transformer, the distribution of moisture in the paper in four thermal zones distributed equally in the height of the winding and diagnosing the safe operating time in which the transformer can be subjected to an overload without the risk of generating water vapor bubbles inside it, using the electronic device (1) according to claims 1 to eleven; and because it includes the stages of:
- adquirir cuatro señales analógicas de entrada las cuales son enviadas a un módulo de acondicionamiento para ser acondicionadas y posteriormente trasmitidas ai módulo de conversión en donde se realiza el cambio de señales analógicas a digitales,  - acquire four analog input signals which are sent to a conditioning module to be conditioned and subsequently transmitted to the conversion module where the change of analog to digital signals is made,
- enviar las señales digitales al primer microcontroiador el cual funciona como unidad de procesamiento y en donde se encuentran implementados los tres modelos de diagnóstico que realizan el diagnóstico en linea,  - send the digital signals to the first microcontroller which functions as a processing unit and where the three diagnostic models that perform the online diagnosis are implemented,
- ejecutar los modelos de diagnóstico en tres etapas, - run the diagnostic models in three stages,
- una vez ejecutados los modelos de diagnóstico en el primer microcontroiador, enviar loa datos al segundo microcontroiador el cual trasmite la información, - once the diagnostic models have been executed in the first microcontroller, send the data to the second microcontroller which transmits the information,
- recibir la información y almacenarla en la interfaz gráfica y en la unidad de almacenamiento del dispositivo (1) la cual tiene capacidad de almacenamiento de información de hasta tres meses, y  - receive the information and store it in the graphical interface and in the storage unit of the device (1) which has information storage capacity of up to three months, and
- evaluar en línea, por el usuario, si el transformador está en condiciones de aceptar una sobrecarga y estimar fuera de línea la evolución de la generación de burbujas de vapor de agua cuando el transformador de potencia es sometido a una sobrecarga temporal.  - evaluate online, by the user, if the transformer is in a position to accept an overload and estimate off-line the evolution of the generation of water vapor bubbles when the power transformer is subjected to a temporary overload.
13. - El dispositivo electrónico (1) de acuerdo con cualquiera de las reivindicaciones anteriores, en donde transformador de potencia es un transformador tipo columnas. 13. - The electronic device (1) according to Any of the preceding claims, wherein the power transformer is a column type transformer.
PCT/MX2015/000100 2014-07-10 2015-07-10 Electronic device for online monitoring of the moisture content of the paper of a potential transformer subjected to overloading, diagnosis of the safe operating time therein, and corresponding method WO2016006994A1 (en)

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