{"id":7677,"date":"2012-01-30T16:22:02","date_gmt":"2012-01-30T18:22:02","guid":{"rendered":"http:\/\/treetech.com.br\/en\/articles\/others\/modernizacao-dos-sistemas-de-medicao-de-temperatura-e-regulacao-de-tensao-de-um-transformador-de-potencia-60-mva"},"modified":"2016-09-06T15:01:35","modified_gmt":"2016-09-06T18:01:35","slug":"modernization-of-temperature-measurement-and-voltage-regulation-systems-of-a-60-mva-power-transformer","status":"publish","type":"post","link":"https:\/\/treetech.com.br\/en\/modernization-of-temperature-measurement-and-voltage-regulation-systems-of-a-60-mva-power-transformer\/","title":{"rendered":"Modernization of temperature measurement and voltage regulation systems of a 60 MVA Power Transformer"},"content":{"rendered":"<div class=\"wpb-content-wrapper\">[vc_row][vc_column width=&#8221;2\/3&#8243;][vc_column_text]\n<h1><strong>Abstract<\/strong><\/h1>\n<p>The objective of this article is to show the advantages of modernization carried out in the voltage regulation systems and measuring temperature of 60 MVA power transformer.<\/p>\n<p>This project served as a pilot for the modernization of other transformers of which results served as the basis of the modernization of substations process.<\/p>\n<p>The work shows the advantages arising from the modernization, as increasing operational reliability and reducing transformer maintenance costs.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\" style=\"height:10px;\"><\/div>[vc_accordion][vc_accordion_tab title=&#8221;Author&#8221;][vc_column_text]\n<table class=\" alignleft\" style=\"color: #7e7c7c; height: 121px;\" width=\"443\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"td_item\" style=\"font-weight: bold; text-align: left;\">Vagner Vasconcellos<\/td>\n<td>CPFL Piratininga<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n[\/vc_column_text][\/vc_accordion_tab][\/vc_accordion][\/vc_column][vc_column width=&#8221;1\/3&#8243;][vc_single_image image=&#8221;5128&#8243; img_size=&#8221;thumbnail&#8221; alignment=&#8221;center&#8221;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div><style>.vcex-button.vcex_69da25bf75917{background:#b2b2b2;color:#ffffff!important;}.vcex-button.vcex_69da25bf75917:hover{background:#008242!important;}<\/style><div class=\"theme-button-wrap textcenter theme-button-block-wrap wpex-block wpex-clear wpex-clr\"><a href=\"http:\/\/treetech.com.br\/wp-content\/uploads\/2016\/02\/XVIISNPTEE_CPFL_Piratiniga_TMeAVR_2003_eng.pdf\" class=\"vcex-button theme-button flat grey medium align-center block vcex_69da25bf75917\" title=\"Download\" target=\"_blank\" rel=\"noopener noreferrer\"><span class=\"vcex-button-inner theme-button-inner wpex-flex wpex-flex-wrap wpex-items-center wpex-justify-center\"><span class=\"vcex-button-icon vcex-icon-wrap theme-button-icon-left\"><span class=\"wpex-icon\" aria-hidden=\"true\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 512 512\"><path d=\"M64 464l48 0 0 48-48 0c-35.3 0-64-28.7-64-64L0 64C0 28.7 28.7 0 64 0L229.5 0c17 0 33.3 6.7 45.3 18.7l90.5 90.5c12 12 18.7 28.3 18.7 45.3L384 304l-48 0 0-144-80 0c-17.7 0-32-14.3-32-32l0-80L64 48c-8.8 0-16 7.2-16 16l0 384c0 8.8 7.2 16 16 16zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\"\/><\/svg><\/span><\/span>Download<span class=\"vcex-button-icon vcex-icon-wrap theme-button-icon-right\"><span class=\"wpex-icon\" aria-hidden=\"true\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 512 512\"><path d=\"M288 32c0-17.7-14.3-32-32-32s-32 14.3-32 32V274.7l-73.4-73.4c-12.5-12.5-32.8-12.5-45.3 0s-12.5 32.8 0 45.3l128 128c12.5 12.5 32.8 12.5 45.3 0l128-128c12.5-12.5 12.5-32.8 0-45.3s-32.8-12.5-45.3 0L288 274.7V32zM64 352c-35.3 0-64 28.7-64 64v32c0 35.3 28.7 64 64 64H448c35.3 0 64-28.7 64-64V416c0-35.3-28.7-64-64-64H346.5l-45.3 45.3c-25 25-65.5 25-90.5 0L165.5 352H64zm368 56a24 24 0 1 1 0 48 24 24 0 1 1 0-48z\"\/><\/svg><\/span><\/span><\/span><\/a><\/div> [\/vc_column][\/vc_row][vc_row][vc_column]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;1.0 &#8211; INTRODUCTION&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]Power transformers are certainly a substation\u2019s most expensive and important\u00a0equipment. For this reason, maintenance of this equipment deserves special attention,\u00a0since their failure implies in great disturbances and huge losses.<\/p>\n<p>According to reference [8], most failures in national transformers in the country have\u00a0been caused by taps under load. On the other hand, due to the need to maintain voltage\u00a0levels at normalized value ranges, deploying these devices on transformers has become\u00a0vital. Temperature measurement devices are another set of vital devices. Thermometers\u00a0play a fundamental role in defining transformer load conditions is a safe and reliable\u00a0manner.<\/p>\n<p>Targeting safer operation of power transformers, linked reduction in maintenance costs,\u00a0a study was undertaken to modernize voltage regulation and temperature measurement\u00a0systems for power transformers.<\/p>\n[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;2.0 &#8211; EVENT HISTORY&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]First, a detailed survey of all maintenance operations performed on devices for voltage\u00a0regulation and temperature gauging. Based on this survey, it was noticed that a fair\u00a0amount of work was done on these devices. In addition to costs involved in these\u00a0maintenance actions, per se, it was also necessary to shut down transformers in order to\u00a0carry out the repair work.<\/p>\n<p>Most problems found were due to lack of accuracy in figures delivered, in particular by\u00a0thermometers. Most of the failures detected on thermometers were on capillaries, that\u00a0due to the action of time (aging) broke and leaked the liquid used in the gauging\u00a0process. Inaccuracy in thermometers caused a lot of inconvenience, such as false\u00a0alarms, unnecessary shut downs and others. In addition to this, these devices operating\u00a0failures and inaccuracy compromised significantly the safe and reliable operation of\u00a0transformers.<\/p>\n<p>Another finding of this survey was the high number of events involving voltage relays\u00a0used in the taps under load of transformers. A few abnormalities detected on relays\u00a0caused, in certain cases, serious problems in tap changers.\u00a0Based on the results of this survey, it was decided to choose a transformer to carry out a\u00a0pilot project for modernizing these devices.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;3.0 &#8211; DEFINITION OF TRANSFORMER&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]In the region of the Baixada Santista, in the state of S\u00e3o Paulo, a 60 MVA transformer\u00a0had its voltage regulation system blocked and temperature measurement devices\u00a0operating precariously. After specific analysis of the equipment, complaints from clients\u00a0about level of output voltage were found. There were also complaints from substation\u00a0operators about the lack of accuracy in the thermometers of this transformer. Due to the\u00a0bad operating performance of the automatic voltage relay, a substation operator had to\u00a0be present full time to perform manual regulation as the load varied during the day.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;4.0 &#8211; DATA SURVEY&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]Initially, a detailed analysis was carried out of the transformer\u2019s entire electrical wiring\u00a0diagram for control of voltage regulation and temperature gauging. The transformer\u00a0chosen is a special equipment, equipped with two taps under load operating in parallel\u00a0and simultaneously. Using two taps under load in one transformer was an option made\u00a0by the manufacturer, in order to allow operation at high currents.<\/p>\n<p>As a function of this particularity of the equipment and the importance of the substation,\u00a0the manufacturer was informed of the intended modernization. After green light was\u00a0received from the manufacturer, a careful market survey was started foe voltage\u00a0regulation and temperature measurement equipment for power transformers. The\u00a0manufacturer of the equipment helped in this by indicating a few companies that\u00a0manufactured this type of devices.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;4.1 &#8211; Basic requirements&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]Based on survey results, CPFL\u2019s maintenance engineering drafted a list of technical\u00a0specifications with the minimum requirements the equipment had to feature:<\/p>\n<ul>\n<li>Possibility for ac and dc power input between 80V and 270V, 50\/60 Hz;<\/li>\n<li>Maximum consumption per device of 15W;<\/li>\n<li>Operating temperature: -10 C to 70 C;<\/li>\n<li>Oil temperature sensor: Pt 100 ohms or Cu 10 ohms;<\/li>\n<li>5A current transformer;<\/li>\n<li>Output current of 20 mA;<\/li>\n<li>1% scale end accuracy; and<\/li>\n<li>RS 485 or RS 232 serial communication.<\/li>\n<\/ul>\n[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;4.2 &#8211; Tests required&#8221; element_type=&#8221;div&#8221; span_background=&#8221;#008242&#8243; span_color=&#8221;#008242&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_row_inner][vc_column_inner][vc_column_text]The devices should also have the following test\/assay certification:<\/p>\n<ul>\n<li>Surges and transients (IEC 266-6);<\/li>\n<li>Impulse (IEC 255-5);<\/li>\n<li>Applied voltage (IEC 255-4\/6);<\/li>\n<li>Climate (IEC 68-2-14); and<\/li>\n<li>Electromagnetic compatibility (IEC 61000-4-2).<\/li>\n<\/ul>\n<p>In addition to the technical data for the equipment and the test certificates, only vendors\u00a0with proven application in power utility companies were considered. During the survey,\u00a0other utility services that already had similar devices installed on their transformers\u00a0were consulted. Information was obtained about the operation of these devices,\u00a0problems found and advantages and disadvantages.<\/p>\n<p>After analyzing several vendors, three were selected for a second stage with more depth,\u00a0based on the particularities of the transformer in case of point. So, since the transformer\u00a0is equipped with two taps under load operating simultaneously, in addition to voltage\u00a0regulation relays, ancillary equipment had to be used to check for parallelism\u00a0supervision of the taps. At the time, only one of the vendors had equipment specific for\u00a0this purpose, while the other two offered this control by way of auxiliary relays.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner][vc_column_inner]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;5.0 &#8211; ANALYSIS OF THE SOLUTIONS PRESENTED&#8221; element_type=&#8221;div&#8221; span_background=&#8221;#008242&#8243; span_color=&#8221;#008242&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]Based on the technical analysis of the propositions, the solution chosen was the one\u00a0that, in addition to being economically advantageous, also offered higher reliability.<\/p>\n<p>Technically, the main reason for this choice was the deployment of micro-controllers\u00a0instead of micro-processors.<\/p>\n<p>Using micro-controllers makes the equipment more reliable and safe for operation in\u00a0substation environment. Since no micro-processors were used in the equipment, there\u00a0was no need to acquire special panels to install them on transformers. This detail\u00a0contributed towards reduction of final cost of modernization, as well as to higher overall\u00a0reliability.<\/p>\n<p>Another point taken into account in choosing this solution was the low number of\u00a0components used in modernizing the equipment. With few components on the panels,\u00a0there is a reduction in the number of defect points, meaning higher overall operational\u00a0reliability.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;6.0 &#8211; VOLTAGE REGULATION&#8221; element_type=&#8221;div&#8221; span_background=&#8221;#008242&#8243; span_color=&#8221;#008242&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]Because this is a special transformer, equipped with two taps under load operating in\u00a0parallel and simultaneously, a special configuration was also used. A parallelism\u00a0supervisor was installed on each tap under load, being used to define the status of\u00a0master for one tap and slave for the other.[\/vc_column_text][vc_row_inner][vc_column_inner]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;7.0 &#8211; TEMPERATURE MEASUREMENT&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]As previously mentioned, the transformer\u2019s temperature measurement system was\u00a0operating precariously, jeopardizing the equipment\u2019s normal operation. Bearing in mind\u00a0the importance of thermometers in the equipment\u2019s safe and reliable operation, a similar\u00a0survey was carried out for the purpose of modernizing these devices, too.<\/p>\n<p>One of the most important requirements analyzed in choosing the temperature\u00a0measurement device was accuracy and reliability of the data delivered. Accuracy is very\u00a0important, since in moments when the equipment must operate under overload, loading\u00a0is done based on maximum oil and winding temperatures.<\/p>\n<p>In addition to the gauging certificates, another point taken into account was operational\u00a0reliability and forms of alerts in case thermometers stop operating or loss of\u00a0communication. This concern being owed in particular, in addition to the equipment\u2019s\u00a0importance in the grid, to being electronic devices operating in aggressive\u00a0environments.<\/p>\n<p>After a technical and economic analysis of the vendors, the same vendor used for the\u00a0voltage regulation relay was chosen. This vendor presented the best technical and\u00a0economical proposition and, in addition to which, their thermometers offered an\u00a0additional protection feature, in case of a communication failure with the transformer:\u00a0fans are automatically switched on and a remote alarm is sent to the operation center,\u00a0pointing out existence of abnormal condition on the device. This way, no reliability is\u00a0lost for the transformer, since, if fan motors are on, refrigeration is assured until the\u00a0problem on the thermometer is solved.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[\/vc_column_inner][\/vc_row_inner][vc_row_inner][vc_column_inner][vc_text_separator title=&#8221;8.0 &#8211; DEFINITIONS OF THE SYSTEMS USED&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]After an exacting analysis of equipment vendors, the same one was chosen for both the\u00a0voltage regulation and parallelism supervision. The definitions were based on technical,\u00a0economical and reliability criteria, in addition to proven efficiency in use by utility\u00a0services.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_line_chart x_values=&#8221;values in thousands of R$&#8221; values=&#8221;%5B%7B%22title%22%3A%22Solution%20A%22%2C%22y_values%22%3A%2215%22%2C%22color%22%3A%22orange%22%7D%2C%7B%22title%22%3A%22Solution%20B%22%2C%22y_values%22%3A%2226%22%2C%22color%22%3A%22juicy-pink%22%7D%2C%7B%22title%22%3A%22Solution%20C%22%2C%22y_values%22%3A%2237%22%2C%22color%22%3A%22blue%22%2C%22custom_color%22%3A%22%2375d69c%22%7D%5D&#8221; title=&#8221;Graphic 1- Cost comparison between the different systems analyzed&#8221;][\/vc_column_inner][\/vc_row_inner][vc_row_inner][vc_column_inner]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;9.0 &#8211; SYSTEM INSTALLATION AND ADJUSTMENT (SET UP)&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]Once the vendor was defined, a project request was issued for installing and adjusting\u00a0the system for analysis and approval. After the project was approved, the logistics\u00a0required in exchanging the systems was programmed, targeting reducing transformer\u00a0downtime as much as possible.<\/p>\n<p>Six hours were required to install the new systems, during which the transformer was\u00a0shut down. During this time, all the old equipment was removed and the new ones, with\u00a0the required changes, were installed.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;10.0 &#8211; ADVANTAGES OF THE NEW SYSTEM&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]The following advantages were obtained from installing the new voltage regulation and\u00a0temperature measurement systems:<\/p>\n<ul>\n<li>Increase in transformer operating reliability;<\/li>\n<li>Reduction of operating costs because of an operator no longer being required at\u00a0the substation full time to do manual voltage regulation;<\/li>\n<li>Improvement of voltage levels resulting from better regulation delivered by new\u00a0system;<\/li>\n<li>Possibility for remote operation and communication;<\/li>\n<li>Possibility for real time monitoring; and<\/li>\n<li>Use of micro-controllers, instead of micro-processors, increasing system\u00a0reliability.<\/li>\n<\/ul>\n<p>As another advantage of the modernized system, maintenance interval for the\u00a0transformer were lengthened, since the main activity of the annual shut down and\u00a0maintenance was a full overhaul of the temperature measurement systems.<\/p>\n<p>At the same substation there are two identical transformers, one with the original design\u00a0system and another with the modernized system. Since modernization, follow up of\u00a0both transformers has been started, using different maintenance criteria for each one, as\u00a0appropriate.<\/p>\n<p>The transformer with the original design system, had its annual shut down and\u00a0maintenance activities with check up of temperature measurement systems, among other\u00a0activities. The modernized transformer only received routine inspections and systems\u00a0were followed up over a period of four years. During this period, there were no shut\u00a0downs for maintenance activities. Systems were followed up using parameter\u00a0comparison such as, for instance, load current and similar loads on other equipment.<\/p>\n<p>During these four years, systems installed did not have any problems and have shown\u00a0they are reliable. After two years of operation, a simulation was carried out for loss of\u00a0communication in order to test the thermometers warning and alarm system. In this test,\u00a0upon loosing communication with the system, the device immediately switched on the\u00a0two sets fans and sounded the problem alarm.[\/vc_column_text][vc_row_inner][vc_column_inner]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_line_chart x_values=&#8221;valores em R$&#8221; values=&#8221;%5B%7B%22title%22%3A%22Modernizing%20Transformer%22%2C%22y_values%22%3A%221100%22%2C%22color%22%3A%22juicy-pink%22%7D%2C%7B%22title%22%3A%22Conventional%20Transformers%22%2C%22y_values%22%3A%222600%22%2C%22color%22%3A%22blue%22%7D%5D&#8221; title=&#8221;Graphic 2 \u2013 Comparative of maintenance costs between transformers&#8221;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[\/vc_column_inner][\/vc_row_inner][vc_column_text]Graphic 2 shows maintenance costs involved in the four-year period, for both transformers in the substation. As can be seen on the chart, by modernizing the systems,\u00a0a cost reduction on the order of 60% in comparison with the conventional system was\u00a0obtained. Another point to be highlighted are the ambient conditions found on the\u00a0substation site, with ambient temperatures above 35 C and relative humidity of the air in\u00a0the 60% to 80% range, most of the time.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;11.0 &#8211; CONCLUSION&#8221; element_type=&#8221;div&#8221; span_background=&#8221;#008242&#8243; span_color=&#8221;#008242&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]The outcome of the modernization is very positive, since, at the end of the process, there\u00a0was an improvement in the transformer\u2019s operating conditions due to its increased\u00a0reliability, in addition to the reduced maintenance costs.<\/p>\n<p>By proper measurement of temperature, the transformer begins to operate in a more\u00a0reliable manner since there is no risk of overloading the equipment beyond norm values\u00a0for oil and winding temperatures. In addition, the temperature measurement system\u00a0offers a favorable concept for use in substations, since it deploys micro-controllers and\u00a0not micro-processors.<\/p>\n<p>Another advantage offered by this temperature measurement device in relation to\u00a0conventional ones is in terms of its maintenance needs. Because this is a totally sealed,\u00a0electronic device, it does not require preventive interventions as do conventional ones.\u00a0In terms of safety requirements, all the equipment has proven to be very reliable, since\u00a0in over two years in operation, in addition to faultlessly in the loss of communication\u00a0simulation activity. Another positive point of modernization was the reestablishment of\u00a0voltage regulation, which contributed materially to the improvement in the quality of\u00a0the energy delivered to clients.<\/p>\n<p>This configuration served as model for transformer automation specifications, in the\u00a0substation automation process that followed this. Based on this work, maintenance\u00a0engineering carries out a procedure to increase time intervals between transformer\u00a0maintenance activities for those that have already had this modernization process.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;12.0 &#8211; REFERENCES&#8221; element_type=&#8221;div&#8221; span_background=&#8221;#008242&#8243; span_color=&#8221;#008242&#8243;][vc_row_inner][vc_column_inner]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]\n<ol>\n<li>IEC 255-5 \u2013 Insulation, coordination for measuring relays and protection equipments requirement and tests.<\/li>\n<li>IEC 68-2-14 \u2013 Environmental testing Part 2: Tests. Test N: Change of temperature.<\/li>\n<li>IEC 61000-4-2 \u2013 Electromagnetic Compatibility (EMC) Part. 4-2. Test and measurement techniques \u2013 Electrostatic discharge Immunity test.<\/li>\n<li>ASSOCIA\u00c7\u00c3O BRASILEIRA DE NORMAS T\u00c9CNICAS. Ensaios b\u00e1sicos clim\u00e1ticos de calor seco com varia\u00e7\u00e3o de temperatura para esp\u00e9cimes que dissipem calor. NBR 6797. Brasil.<\/li>\n<li>ASSOCIA\u00c7\u00c3O BRASILEIRA DE NORMAS T\u00c9CNICAS. Aplica\u00e7\u00e3o de cargas em transformadores de pot\u00eancia \u2013 Procedimento. NBR 5416. Brasil.<\/li>\n<li>Milasch, M. Manuten\u00e7\u00e3o de Transformadores em L\u00edquido Isolante.<\/li>\n<li>Oliveira J.C, Cogo J.R, Abreu J.P.G. Transformadores \u2013 Teoria e Ensaios.<\/li>\n<li>Mendes J.C. &#8211; Redu\u00e7\u00e3o de falhas em grandes transformadores de alta tens\u00e3o \u2013 Tese de Doutorado \u2013 Escola Polit\u00e9cnica da Universidade de S\u00e3o Paulo \u2013 1995.<\/li>\n<\/ol>\n[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_column][\/vc_row]\n<\/div>","protected":false},"excerpt":{"rendered":"<p>[vc_row][vc_column width=&#8221;2\/3&#8243;][vc_column_text] Abstract The objective of this article is to show the advantages of modernization carried out in the voltage regulation systems and measuring temperature of 60 MVA power transformer. This project served as a pilot for the modernization of other transformers of which results served as the basis of the modernization of substations process.&hellip;<\/p>\n","protected":false},"author":1,"featured_media":5345,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[134],"tags":[],"class_list":["post-7677","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-distribution","entry","has-media"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/posts\/7677","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/comments?post=7677"}],"version-history":[{"count":0,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/posts\/7677\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/media\/5345"}],"wp:attachment":[{"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/media?parent=7677"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/categories?post=7677"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/tags?post=7677"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}