{"id":10820,"date":"2026-08-29T23:43:13","date_gmt":"2026-08-29T15:43:13","guid":{"rendered":"https:\/\/q8bbzjnpm5.wpdns.site\/?p=10820"},"modified":"2026-08-29T23:43:13","modified_gmt":"2026-08-29T15:43:13","slug":"power-transformers-analysis-of-functions-and-advantages-1","status":"publish","type":"post","link":"https:\/\/subian-electric.com\/pt\/news\/power-transformers-analysis-of-functions-and-advantages-1\/","title":{"rendered":"Transformadores de Pot\u00eancia: An\u00e1lise de Fun\u00e7\u00f5es e Vantagens"},"content":{"rendered":"<p>Um engenheiro de compras em uma planta de cimento recebeu uma cota\u00e7\u00e3o para dois transformadores de 5 MVA, dos quais um custa $68.000 e o outro $95.000, e o engenheiro estava confuso sobre por que h\u00e1 uma diferen\u00e7a de pre\u00e7o e s\u00f3 descobriria isso ap\u00f3s verificar as estat\u00edsticas de perda, classes de resfriamento e material de isolamento de ambos os transformadores. Essa epifania, quando os princ\u00edpios e benef\u00edcios do uso de transformadores de pot\u00eancia se transformam de teoria em realidade, \u00e9 o que este artigo abordar\u00e1. Transformadores de pot\u00eancia s\u00e3o apenas algumas caixas feitas de a\u00e7o, no entanto, suas especificidades internas determinam qu\u00e3o eficiente e dur\u00e1vel o transformador seria, bem como seu custo total de propriedade.<\/p>\n<p>Neste artigo, analisamos qual \u00e9 o verdadeiro prop\u00f3sito dos transformadores de pot\u00eancia: transforma\u00e7\u00e3o de tens\u00e3o, isolamento, correspond\u00eancia de imped\u00e2ncia, regula\u00e7\u00e3o, etc. Investigamos quais benef\u00edcios um bom design desses transformadores pode trazer, entre os quais est\u00e3o: efici\u00eancia acima de 99%, vida \u00fatil superior a 30 anos e capacidade de sobrecarga.<\/p>\n<blockquote><p>As fun\u00e7\u00f5es de um transformador de pot\u00eancia incluem mudar n\u00edveis de tens\u00e3o, manter isolamento el\u00e9trico entre circuitos, igualar as imped\u00e2ncias e controlar a tens\u00e3o. Suas vantagens quando projetadas corretamente s\u00e3o efici\u00eancias entre 98% e 99,7% e vidas operacionais entre 30 e 40 anos com pouca manuten\u00e7\u00e3o. A opera\u00e7\u00e3o do aparelho \u00e9 regulamentada pela IEC 60076-1; as perdas e efici\u00eancias s\u00e3o fornecidas para diferentes cargas e s\u00e3o usadas para a classifica\u00e7\u00e3o de custo de propriedade que distingue propostas confi\u00e1veis das baratas.<\/p><\/blockquote>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-10822\" src=\"https:\/\/subian-electric.com\/wp-content\/uploads\/2026\/08\/Power-Transformer-Analysis-of-Functions-and-Advantages.webp\" alt=\"Power Transformer Analysis of Functions and Advantages\" width=\"1448\" height=\"1086\" \/><\/p>\n<hr \/>\n<h2 id=\"functions\">As Cinco Fun\u00e7\u00f5es Principais de um Transformador de Pot\u00eancia<\/h2>\n<p>Um transformador de pot\u00eancia n\u00e3o \u00e9 apenas um aparelho de uso \u00fanico; na verdade, ele desempenha v\u00e1rias fun\u00e7\u00f5es el\u00e9tricas diferentes simultaneamente:<\/p>\n<table border=\"1\" cellspacing=\"0\" cellpadding=\"6\">\n<caption>As Fun\u00e7\u00f5es Principais dos Transformadores de Pot\u00eancia<\/caption>\n<tbody>\n<tr>\n<th>Fun\u00e7\u00e3o<\/th>\n<th>O que faz<\/th>\n<th>Exemplo Pr\u00e1tico<\/th>\n<\/tr>\n<tr>\n<td>Transforma\u00e7\u00e3o de tens\u00e3o<\/td>\n<td>Eleva ou reduz a tens\u00e3o pela rela\u00e7\u00e3o de espiras<\/td>\n<td>18 kV \u2192 400 kV em um transformador GSU<\/td>\n<\/tr>\n<tr>\n<td>Isolamento el\u00e9trico<\/td>\n<td>Separa circuitos prim\u00e1rios e secund\u00e1rios galvanicamente<\/td>\n<td>Isolamento entre gerador e rede<\/td>\n<\/tr>\n<tr>\n<td>Adapta\u00e7\u00e3o de imped\u00e2ncia<\/td>\n<td>Igualar imped\u00e2ncias de fonte e carga para transfer\u00eancia de pot\u00eancia eficiente<\/td>\n<td>Conectando um gerador de alta imped\u00e2ncia a uma linha de baixa imped\u00e2ncia<\/td>\n<\/tr>\n<tr>\n<td>Regula\u00e7\u00e3o de tens\u00e3o<\/td>\n<td>Mant\u00e9m a tens\u00e3o de sa\u00edda contra varia\u00e7\u00f5es de carga atrav\u00e9s de comutadores de deriva\u00e7\u00e3o<\/td>\n<td>OLTC mantendo o barramento de 20 kV dentro de \u00b12%<\/td>\n<\/tr>\n<tr>\n<td>Interconex\u00e3o de sistemas<\/td>\n<td>Conecta diferentes n\u00edveis de tens\u00e3o, fases e arranjos de aterramento<\/td>\n<td>Transformador auto-transformador de 220 kV \u2194 110 kV<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Essas fun\u00e7\u00f5es correspondem a atributos de design espec\u00edficos: a rela\u00e7\u00e3o de espiras correlaciona-se com o n\u00famero de enrolamentos, a fun\u00e7\u00e3o isolante com o sistema diel\u00e9trico, a fun\u00e7\u00e3o de correspond\u00eancia com a reat\u00e2ncia de fuga, a fun\u00e7\u00e3o de regula\u00e7\u00e3o com o comutador de deriva\u00e7\u00e3o, assim como a interconex\u00e3o com o grupo vetorial e o design do arranjo neutro.<\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-10821\" src=\"https:\/\/subian-electric.com\/wp-content\/uploads\/2026\/08\/The-Five-Core-Functions-of-a-Power-Transformer.webp\" alt=\"As Cinco Fun\u00e7\u00f5es Principais de um Transformador de Pot\u00eancia\" width=\"1448\" height=\"1086\" \/><\/p>\n<h2 id=\"advantages\">Vantagens Mensur\u00e1veis de um Transformador de Pot\u00eancia Bem Projetado<\/h2>\n<p>Ao falar sobre transformadores de pot\u00eancia, os engenheiros se referem a n\u00fameros espec\u00edficos:<\/p>\n<ul>\n<li>Efici\u00eancia \u2013 transformadores de pot\u00eancia t\u00eam grandes m\u00e1quinas operando em torno de 99,0 \u2013 99,7%. Por exemplo, um transformador de 100 MVA com efici\u00eancia de 99,5% tem apenas 500 kW desperdi\u00e7ados em plena carga.<\/li>\n<li>Longevidade \u2013 com a manuten\u00e7\u00e3o adequada, os transformadores funcionam por mais de 30-40 anos. Muitos transformadores constru\u00eddos na d\u00e9cada de 1960 ainda est\u00e3o em opera\u00e7\u00e3o.<\/li>\n<li>Capacidade de sobrecarga \u2013 a margem da classe de resfriamento permite sobrecarga de 120% a 160% por um tempo espec\u00edfico de acordo com a instru\u00e7\u00e3o de carga IEC 60076-7.<\/li>\n<li>A baixa necessidade de servi\u00e7o \u2013 v\u00e1rios dispositivos n\u00e3o possuem partes m\u00f3veis. Os \u00fanicos trabalhos de servi\u00e7o necess\u00e1rios s\u00e3o os testes de \u00f3leo e a troca de juntas.<\/li>\n<li>Alta taxa de confiabilidade \u2013 as falhas est\u00e3o abaixo de 1% por ano para todos os dispositivos na frota da empresa de utilidade.<\/li>\n<li>Flexibilidade da rede \u2013 o trabalho paralelo de m\u00e1quinas, a mudan\u00e7a de tomadas e o deslocamento de fase dos transformadores permitem gerenciar o fluxo de energia de forma din\u00e2mica.<\/li>\n<\/ul>\n<p>Essas vantagens ajudam a entender por que a mesma constru\u00e7\u00e3o do transformador tem sido usada por 130 anos \u2013 os princ\u00edpios f\u00edsicos s\u00e3o est\u00e1veis e o benef\u00edcio econ\u00f4mico est\u00e1 presente.<\/p>\n<h2 id=\"how\">Como a Fun\u00e7\u00e3o \u00e9 Fornecida: Enrolamentos, N\u00facleo &amp; Tomadas<\/h2>\n<p>As fun\u00e7\u00f5es listadas s\u00e3o realizadas devido a v\u00e1rios componentes projetados:<\/p>\n<table border=\"1\" cellspacing=\"0\" cellpadding=\"6\">\n<caption>Componentes &amp; as Fun\u00e7\u00f5es que Eles Fornecem<\/caption>\n<tbody>\n<tr>\n<th>Componente<\/th>\n<th>Contribui\u00e7\u00e3o<\/th>\n<th>Escolha T\u00edpica em Design Premium<\/th>\n<\/tr>\n<tr>\n<td>N\u00facleo<\/td>\n<td>Caminho de fluxo de baixa perda<\/td>\n<td>A\u00e7o sil\u00edcio orientado a gr\u00e3o (classe M4\/M5) ou amorfo<\/td>\n<\/tr>\n<tr>\n<td>Enrolamentos<\/td>\n<td>Rela\u00e7\u00e3o de espiras, densidade de corrente<\/td>\n<td>Cobre OFHC, isolamento classe F\/H<\/td>\n<\/tr>\n<tr>\n<td>Comutador de deriva\u00e7\u00e3o<\/td>\n<td>Regula\u00e7\u00e3o de tens\u00e3o<\/td>\n<td>Sob carga (OLTC) com interruptores a v\u00e1cuo ou transi\u00e7\u00e3o de resistor<\/td>\n<\/tr>\n<tr>\n<td>Sistema de isolamento<\/td>\n<td>Resist\u00eancia diel\u00e9trica, classe t\u00e9rmica<\/td>\n<td>Papel prensado de alta densidade + \u00f3leo mineral ou \u00e9ster<\/td>\n<\/tr>\n<tr>\n<td>Sistema de resfriamento<\/td>\n<td>Capacidade de carga<\/td>\n<td>Radiadores, ventiladores, bombas de \u00f3leo (ONAN \u2192 ODAF)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>A intera\u00e7\u00e3o \u00e9 importante: um n\u00facleo de a\u00e7o de baixa qualidade aumenta as perdas em vazio em 10% a 20% enquanto usa a mesma classifica\u00e7\u00e3o; fios finos aumentam as perdas I\u00b2R; um trocador de tomadas m\u00e9dio \u00e9 o primeiro componente a falhar. Decis\u00f5es de engenharia premium \u00e9 sobre o que os $95.000 oferecidos no exemplo acima se referiam.<\/p>\n<h2 id=\"efficiency\">Efici\u00eancia &amp; Economia de Perdas: Por que 0.5% \u00e9 Importante<\/h2>\n<p>Os transformadores dissipam energia el\u00e9trica o tempo todo. Qualquer dispositivo que esteja energizado por 24 horas por dia, 365 dias por ano, incorre em perdas em vazio mesmo que n\u00e3o esteja carregando. O m\u00e9todo padr\u00e3o de compara\u00e7\u00e3o de equipamentos \u00e9 o m\u00e9todo de perda capitalizada, que permite transformar ambos os componentes em valor presente:<\/p>\n<table border=\"1\" cellspacing=\"0\" cellpadding=\"6\">\n<caption>Dados T\u00edpicos de Perda por Classifica\u00e7\u00e3o de Transformador<\/caption>\n<tbody>\n<tr>\n<th>Classifica\u00e7\u00e3o<\/th>\n<th>Perda em Vazio<\/th>\n<th>Perda de Carga (75\u00b0C)<\/th>\n<th>Efici\u00eancia @ Carga Total<\/th>\n<\/tr>\n<tr>\n<td>1 MVA \/ 11 kV<\/td>\n<td>\u22481,150 W<\/td>\n<td>\u224810,500 W<\/td>\n<td>\u224898.8%<\/td>\n<\/tr>\n<tr>\n<td>20 MVA \/ 110 kV<\/td>\n<td>\u224814 kW<\/td>\n<td>\u224898 kW<\/td>\n<td>\u224899.4%<\/td>\n<\/tr>\n<tr>\n<td>100 MVA \/ 220 kV<\/td>\n<td>\u224845 kW<\/td>\n<td>\u2248320 kW<\/td>\n<td>\u224899.6%<\/td>\n<\/tr>\n<tr>\n<td>400 MVA \/ 400 kV<\/td>\n<td>\u2248130 kW<\/td>\n<td>\u22481,100 kW<\/td>\n<td>\u224899.7%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Os transformadores dissipam energia el\u00e9trica o tempo todo. Qualquer dispositivo que esteja energizado por 24 horas por dia, 365 dias por ano, incorre em perdas em vazio mesmo que n\u00e3o esteja carregando. O m\u00e9todo padr\u00e3o de compara\u00e7\u00e3o de equipamentos \u00e9 o m\u00e9todo de perda capitalizada, que permite transformar ambos os componentes em valor presente:<\/p>\n<h2 id=\"types\">Functions by Transformer Type<\/h2>\n<p>Each family of transformers has its own parameter profile optimization.<\/p>\n<table border=\"1\" cellspacing=\"0\" cellpadding=\"6\">\n<caption>Function Emphasis by Transformer Type<\/caption>\n<tbody>\n<tr>\n<th>Tipo<\/th>\n<th>Fun\u00e7\u00e3o Prim\u00e1ria<\/th>\n<th>Secondary Function<\/th>\n<th>Aplica\u00e7\u00e3o T\u00edpica<\/th>\n<\/tr>\n<tr>\n<td>GSU<\/td>\n<td>Eleva\u00e7\u00e3o<\/td>\n<td>Isolation, fault limiting<\/td>\n<td>Power plants, wind\/solar<\/td>\n<\/tr>\n<tr>\n<td>Distribution<\/td>\n<td>Final step-down<\/td>\n<td>Partial-load efficiency<\/td>\n<td>Utility feeders, buildings<\/td>\n<\/tr>\n<tr>\n<td>Autotransformador<\/td>\n<td>Interconnection<\/td>\n<td>Cost\/size saving<\/td>\n<td>HV grid ties<\/td>\n<\/tr>\n<tr>\n<td>Isolation<\/td>\n<td>Galvanic separation<\/td>\n<td>Noise\/DC blocking<\/td>\n<td>Hospitals, data centers, test labs<\/td>\n<\/tr>\n<tr>\n<td>Phase-shifting<\/td>\n<td>Power flow control<\/td>\n<td>Loop-flow management<\/td>\n<td>Meshed EHV networks<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>An isolation transformer can operate on 1:1 ratio i.e. no voltage changes at all as its sole function is to provide electrical isolation, block DC, and eliminate electromagnetic interference. This means that the definition of \u201ctransformer\u201d is broader than just \u201ca voltage changing device.\u201d<\/p>\n<h2 id=\"specs\">Function-Driven Specifications<\/h2>\n<table border=\"1\" cellspacing=\"0\" cellpadding=\"6\">\n<caption>Key Specifications &amp; the Function They Serve<\/caption>\n<tbody>\n<tr>\n<th>Especifica\u00e7\u00e3o<\/th>\n<th>Valor T\u00edpico<\/th>\n<th>Function Served<\/th>\n<\/tr>\n<tr>\n<td>Rated power (kVA\/MVA)<\/td>\n<td>200 kVA\u20131,200 MVA<\/td>\n<td>Overall capability envelope<\/td>\n<\/tr>\n<tr>\n<td>Voltage ratio<\/td>\n<td>e.g. 110\/20 kV<\/td>\n<td>Transforma\u00e7\u00e3o de tens\u00e3o<\/td>\n<\/tr>\n<tr>\n<td>Tens\u00e3o de imped\u00e2ncia<\/td>\n<td>6%\u201315%<\/td>\n<td>Fault limiting, load sharing<\/td>\n<\/tr>\n<tr>\n<td>Grupo vetorial<\/td>\n<td>YNd11, Dyn11<\/td>\n<td>Phase alignment &amp; interconnection<\/td>\n<\/tr>\n<tr>\n<td>Faixa de deriva\u00e7\u00e3o<\/td>\n<td>\u00b110%\u2013\u00b116%<\/td>\n<td>Regula\u00e7\u00e3o de tens\u00e3o<\/td>\n<\/tr>\n<tr>\n<td>Insulation level (BIL)<\/td>\n<td>550 kV @ 110 kV class<\/td>\n<td>Dielectric withstand, isolation integrity<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The parameters mentioned above represent a contract for service: the buyer is really paying for certain electrical performance.<\/p>\n<h2 id=\"maintenance\">Maintenance Advantages &amp; Realistic Service Costs<\/h2>\n<p>A unique feature of power transformers is their prolonged maintenance timeline that usually takes place over the course of several years:<\/p>\n<ul>\n<li>Oil sampling, which consists of a dissolved gas analysis (DGA) of the oil, is done every 6 to 12 months for vital units. The cost of a complete oil test lies between $200 and $1,000 per sample.<\/li>\n<li>Oil replacement takes place once every 10-20 years where mineral oil systems are concerned. A transformer with a capacity of 20 MVA has a need for around 8,000 &#8211; 12,000 liters of oil.<\/li>\n<li>Both the gaskets and the breathers also need to be replaced: the silica-gel replacement has to happen every year and the gaskets are changed every 5 to 8 years.<\/li>\n<li>Service schedules for tap changers are defined by the manufacturers and these are performed approximately once every 2-5 years.<\/li>\n<li>Another maintenance operation is annual inspection which consists of visual inspection, thermal imaging, and leak testing which is typically $2,000 \u2013 $8,000 per unit.<\/li>\n<\/ul>\n<p>This is nothing compared to rotating machinery which needs constant bearing changes and vibration monitoring.<\/p>\n<h2 id=\"applications\">Applications Where Function Matters Most<\/h2>\n<ul>\n<li>Interconnected utility grids \u2014 auto-transformers and step-down transformers are utilized to regulate the power flow.<\/li>\n<li>Renewable energy industry \u2014 GSU and collection transformers are utilized to handle irregular generation.<\/li>\n<li>Intensive industry \u2014 furnaces and rectifiers transformers are used to feed arc furnaces and electrolysis.<\/li>\n<li>Sensitive facilities \u2014 isolation transformers are used to protect medical imaging.<\/li>\n<li>Marine and offshore \u2014 specialized equipment used in areas with heavy vibrations, salt, and demanding sizes.<\/li>\n<\/ul>\n<h2 id=\"brands\">Top Brands &amp; Price Analysis<\/h2>\n<p>Premium brands in transformers win projects due to engineering history, losses warranties, and post-sale communications &#8211; however, the technologies are the same, as everyone adheres to IEC 60076 standards. The table below illustrates the price estimates of a 20 MVA\/110 kilovolt oil-immersed transformer.<\/p>\n<table border=\"1\" cellspacing=\"0\" cellpadding=\"6\">\n<caption>Brand Comparison &amp; Indicative Prices (20 MVA, 110 kV)<\/caption>\n<tbody>\n<tr>\n<th>Marca<\/th>\n<th>Pa\u00eds<\/th>\n<th>Positioning<\/th>\n<th>Indicative Price<\/th>\n<\/tr>\n<tr>\n<td>Hitachi Energy<\/td>\n<td>Switzerland\/Japan<\/td>\n<td>Technology leader, EHV\/HVDC<\/td>\n<td>$450,000\u2013$700,000<\/td>\n<\/tr>\n<tr>\n<td>Siemens Energy<\/td>\n<td>Alemanha<\/td>\n<td>EHV, digital substations<\/td>\n<td>$430,000\u2013$680,000<\/td>\n<\/tr>\n<tr>\n<td>Schneider Electric<\/td>\n<td>Fran\u00e7a<\/td>\n<td>Distribution &amp; MV leadership<\/td>\n<td>$280,000\u2013$450,000<\/td>\n<\/tr>\n<tr>\n<td>GE Vernova<\/td>\n<td>EUA<\/td>\n<td>Utility GSU projects<\/td>\n<td>$420,000\u2013$650,000<\/td>\n<\/tr>\n<tr>\n<td>Hyosung<\/td>\n<td>South Korea<\/td>\n<td>Large MVA, EHV<\/td>\n<td>$380,000\u2013$600,000<\/td>\n<\/tr>\n<tr>\n<td>TBEA<\/td>\n<td>China<\/td>\n<td>Scale + EPC<\/td>\n<td>$180,000\u2013$320,000<\/td>\n<\/tr>\n<tr>\n<td>Jiangsu Subian Electric Power<\/td>\n<td>China<\/td>\n<td>Custom, OEM\/ODM, value<\/td>\n<td>$160,000\u2013$300,000<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The price depends on specifications, losses, and regions. Buyers who wish to buy transformers complying with IEC 60076 standards without paying for the brand can turn to Jiangsu Subian Electric Power, which manufactures power and distribution transformers of the 50 kVA-220 kV range, both oil-immersed and dry, with optional on-load tap changers and complete factory test reports. The engineers of Jiangsu Subian Electric Power modify ratios, cooling types, and vector groups, while their prices are typically 30%-50% lower than their European counterparts&#8217; prices, and every purchase comes with a third-party assessment.<\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-10823\" src=\"https:\/\/subian-electric.com\/wp-content\/uploads\/2026\/08\/How-to-Evaluate-a-Transformers-Engineering.webp\" alt=\"How to Evaluate a Transformer's Engineering\" width=\"1448\" height=\"1086\" \/><\/p>\n<h2 id=\"evaluate\">How to Evaluate a Transformer&#8217;s Engineering<\/h2>\n<ul>\n<li>Initially, consult the loss table to get the figures for no-load and load loss which provides information about the core and the conductor quality.<\/li>\n<li>Make inquiries regarding the compliance of the type tests with the accepted standards, such as IEC 60076-1\/2\/3\/5, which involve tests for temperature rise and impulse tests.<\/li>\n<li>Examine the winding conductor and core steel, as these should be made of premium materials such as silicon steel and copper.<\/li>\n<li>Establish the manufacturer of the tap changer employed since having the one manufactured by MR (Maschinenfabrik Reinhausen) will help to mitigate any malfunction associated with this particulary device.<\/li>\n<li>Have a comparison made between losses, or difference in profitability, which is calculated on the basis of expected losses over 20-30 years.<\/li>\n<li>Check the temperature for cooling purposes against the ONAN\/ONAF double rating.<\/li>\n<li>Ask for production test reports and be sure to witness it.<\/li>\n<\/ul>\n<h2 id=\"faq\">Perguntas Frequentes<\/h2>\n<h3>What is the main function of a power transformer?<\/h3>\n<p>The primary task is converting voltage \u2013 increase or decrease the voltage level without changing frequency and apparent power by virtue of electromagnetic induction. Another equally important task is making circuits electrically isolated from each other, which becomes possible in the process of transmission in the form of step-up and step-down operations.<\/p>\n<h3>What efficiency can I expect from a modern power transformer?<\/h3>\n<p>Distribution transformers usually achieve efficiency levels of around 98%\u201399%, while big power transformers operate with efficiency levels of 99%\u201399.7% at the specified maximum load. It must be mentioned that power efficiency depends on load; the highest level of power efficiency is usually seen at 50%\u201375% load, which is the reason engineers design transformers to operate in this range. In this context, the comparison must be done with the help of the provided values of the losses rather than the efficiency percentage alone.<\/p>\n<h3>Why does a 20 MVA transformer cost $160,000 from one supplier and $700,000 from another?<\/h3>\n<p>The functions performed by both units are the same; the difference is in the engineered content: the loss guarantees (low-loss design uses more metal and superior core steel), brand of the tap changer, type of the cooling system, test history of the units, service support, and others. Usually, one can justify the higher upfront spending because of the lower cost of running a capitalized loss over 25 years of operation.<\/p>\n<h3>What is the advantage of an on-load tap changer (OLTC)?<\/h3>\n<p>The OLTC allows changing taps under the power condition of the transformer, allowing changing the voltage level automatically according to the load. In the absence of OLTC voltage change ranges from 5% to 10% per day, making the work of motors shorter and causing misoperation of the vulnerable equipment.<\/p>\n<h3>How often does a power transformer need maintenance?<\/h3>\n<p>The routine oil sampling is recommended for each 6 to 12 months period for critical units. Other functional activities include every-year visual inspection and thermal inspection of the transformer, as well as tap changer servicing every 2 to 5 years. In the course of operations, the normal lifespan of the well-maintained power transformer is around 30 to 40 years.<\/p>\n<h2 id=\"references\">Refer\u00eancias<\/h2>\n<ul>\n<li><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/639\" rel=\"nofollow noopener\" target=\"_blank\">IEC 60076-1: Power Transformers \u2014 General<\/a> \u2014 Ratings, tolerances, and general requirements that define function and test scope.<\/li>\n<li><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/641\" rel=\"nofollow noopener\" target=\"_blank\">IEC 60076-7: Loading Guide for Oil-Immersed Power Transformers<\/a> \u2014 The guide for overload capability and thermal aging.<\/li>\n<li><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/645\" rel=\"nofollow noopener\" target=\"_blank\">IEC 60076-5: Ability to Withstand Short Circuit<\/a> \u2014 Short-circuit withstand requirements and tests.<\/li>\n<li><a href=\"https:\/\/ieeexplore.ieee.org\/document\/5307241\" rel=\"nofollow noopener\" target=\"_blank\">IEEE C57.12.00: General Requirements for Liquid-Immersed Transformers<\/a> \u2014 North American companion standard.<\/li>\n<li><a href=\"https:\/\/www.reinhausen.com\/en\" rel=\"nofollow noopener\" target=\"_blank\">Maschinenfabrik Reinhausen (MR) Tap Changer Technology<\/a> \u2014 Industry reference for on-load tap changer design and maintenance.<\/li>\n<li><a href=\"https:\/\/www.siemens-energy.com\/global\/en\/offerings\/transformers.html\" rel=\"nofollow noopener\" target=\"_blank\">Siemens Energy Transformers<\/a> \u2014 Benchmark examples of modern transformer engineering.<\/li>\n<\/ul>\n<h2 id=\"conclusion\">Conclus\u00e3o<\/h2>\n<p>Power transformers have a straightforward appearance, yet they fulfil numerous responsibilities such as voltage transformation, impedance matching, regulation, interconnection, and isolation, which all combine to ensure that the grid functions. They are beneficial if properly designed, such as providing 30 to 40 years of service life, efficiencies equal to or exceeding 99 percent, low maintenance levels, and overload capability.<\/p>\n<ul>\n<li>Evaluate transformers on the basis of losses only, not costs. Losses determine the lifetime cost of the transformer.<\/li>\n<li>Specifications should meet the functional requirements of the transformer such as the ratio, impedance, vector group, tap range, type of cooling, and BIL.<\/li>\n<li>Compare at least three kinds of transformers from different manufacturers under similar specifications by means of the capitalized-loss model.<\/li>\n<li>The budget should be in the range of $25,000-$90,000 for transformers ranging from 1 to 5 MVA and $160,000-$300,000 for the 20 MVA transformer.<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>A procurement engineer in a cement plant was offered a quote for two 5 MVA transformers, of which one costs $68,000 and the other one $95,000, and the engineer was confused about why there is a price gap and would only find that out after checking the loss statistics, cooling classes, and insulation material of [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":10822,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[77],"tags":[],"class_list":["post-10820","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/posts\/10820","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/comments?post=10820"}],"version-history":[{"count":2,"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/posts\/10820\/revisions"}],"predecessor-version":[{"id":10998,"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/posts\/10820\/revisions\/10998"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/media\/10822"}],"wp:attachment":[{"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/media?parent=10820"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/categories?post=10820"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/subian-electric.com\/pt\/wp-json\/wp\/v2\/tags?post=10820"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}