{"id":8109,"date":"2014-01-30T16:38:44","date_gmt":"2014-01-30T18:38:44","guid":{"rendered":"http:\/\/treetech.com.br\/en\/articles\/others\/a-evolucao-dos-sistemas-de-monitoramento-on-line-de-transformadores-e-reatores-sigma-na-eletrosul"},"modified":"2016-10-13T17:04:57","modified_gmt":"2016-10-13T20:04:57","slug":"evolution-of-the-sigma-online-monitoring-systems-for-transformers-and-reactors-at-eletrosul","status":"publish","type":"post","link":"https:\/\/treetech.com.br\/en\/evolution-of-the-sigma-online-monitoring-systems-for-transformers-and-reactors-at-eletrosul\/","title":{"rendered":"Evolution of the Sigma online monitoring systems for transformers and reactors at Eletrosul"},"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>High voltage assets in substations, such as transformer and reactors, are crucial for the safe operation and continuity of the electric power supply. Consequently online monitoring systems have been used to increase the reliability and availability of those pieces of equipment, and at the same time, to reduce costs.\u00a0 Eletrobras Eletrosul started to implement online monitoring in power transformers in 2001 with the Sigma system. This paper presents the deployment history of the Sigma monitoring system at Eletrosul Eletrobras, as well as its evolution along time, together with the outcomes and benefits brought by improvements in the system.[\/vc_column_text][\/vc_column][vc_column width=&#8221;1\/3&#8243;][vc_single_image image=&#8221;5377&#8243; img_size=&#8221;thumbnail&#8221; alignment=&#8221;center&#8221; onclick=&#8221;img_link_large&#8221;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div><style>.vcex-button.vcex_69d7e4487614d{background:#b2b2b2;color:#ffffff!important;}.vcex-button.vcex_69d7e4487614d: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\/XXI-SNPTEE_Eletrosul_SistemasEletrosul_2011_ing.pdf\" class=\"vcex-button theme-button flat grey medium align-center block vcex_69d7e4487614d\" 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 width=&#8221;2\/3&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\" style=\"height:10px;\"><\/div>[vc_accordion][vc_accordion_tab title=&#8221;Authors&#8221;][vc_column_text]\n<table class=\" alignleft\" style=\"color: #7e7c7c; height: 227px;\" width=\"497\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"td_item\" style=\"font-weight: bold; text-align: left;\">Eletrobras Eletrosul<\/td>\n<td>Cl\u00e1udio Severino<\/td>\n<\/tr>\n<tr>\n<td class=\"td_item\" style=\"font-weight: bold; text-align: left;\">Eletrobras Eletrosul<\/td>\n<td>Pedro Peroni<\/td>\n<\/tr>\n<tr>\n<td class=\"td_item\" style=\"font-weight: bold; text-align: left;\">Eletrobras Eletrosul<\/td>\n<td>Francisco Zacarias Peroni<\/td>\n<\/tr>\n<tr>\n<td class=\"td_item\" style=\"font-weight: bold; text-align: left;\">Eletrobras Eletrosul<\/td>\n<td>Giuliano Pereira<\/td>\n<\/tr>\n<tr>\n<td class=\"td_item\" style=\"font-weight: bold; text-align: left;\">Treetech Sistemas Digitais Ltda.<\/td>\n<td>Marcos E. G. Alves<\/td>\n<\/tr>\n<tr>\n<td class=\"td_item\" style=\"font-weight: bold; text-align: left;\">Treetech Sistemas Digitais Ltda.<\/td>\n<td>Lu\u00eds Lopes<\/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_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]Substation high voltage equipment such as power transformer, shunt reactors, current transformers, capacitive voltage transformers, high voltage circuit breakers and disconnect switches are the production assets of the electric power generation plants, and as such are crucial for the safe operation and continuity of the electric power supply.\u00a0 When operated under appropriate conditions and managed accurately, these assets become a major factor of operational and economic efficiency and competitiveness for the sector&#8217;s utilities.<\/p>\n<p>In order to ensure greater reliability and availability of the equipment while cutting operating and maintenance costs, as well as increasing maintenance efficiency, the monitoring and diagnostic systems for online monitoring and diagnostic of the asset state have spread over the last decade, providing a tool for the migration from preventive to predictive maintenance and to a maintenance philosophy centered on reliability [1] [2].<\/p>\n<p>Great emphasis has been given to power transformers and shunt reactors, since these are considered the main assets of a substation due to being essential for the generation and transmission of the electric power, and to having high replacement costs and requiring a long time to be manufactured. .<\/p>\n<p>This paper presents a brief history of the deployment and evolution of these systems in Eletrobras Eletrosul and the results obtained.[\/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; IMPLEMENTATION OF TRANSFORMER ONLINE MONITORING AT ELETROSUL&#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 context above, and as a company which traditionally uses innovative technologies and is a benchmark for the best practices in asset management, Eletrobras Eletrosul started to implement in 2001 the online monitoring of power transformers, seeking to achieve the following general objectives:<\/p>\n<ul>\n<li>Online diagnostics of the high voltage equipment state<\/li>\n<li>Reduced risk of failure;<\/li>\n<li>Service Life extension and control;<\/li>\n<li>Migration to predictive maintenance:<\/li>\n<li>Reduction of maintenance costs;<\/li>\n<li>Increased equipment availability in the system;<\/li>\n<li>Reduced costs due to equipment availability;<\/li>\n<li>Optimized asset use;<\/li>\n<li>Better insurance premium negotiation;<\/li>\n<li>Preservation of the corporate image;<\/li>\n<\/ul>\n<p>The deployment started by two 230\/138 kV 150 MVA three-phase transformers at the Itaja\u00ed substation, with on-load tap changers [3] shown in Figure 1, where the Treetech Sigma system was installed, with a basic architecture like the one shown in Figure 2.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_single_image image=&#8221;8106&#8243; alignment=&#8221;center&#8221; onclick=&#8221;img_link_large&#8221;][vc_column_text]\n<p style=\"text-align: center;\"><strong><em>Fig. 1.\u00a0 First monitored transformers at Itaja\u00ed substation, 138\/13, 8 kV 150 MVA<\/em><\/strong><\/p>\n[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_single_image image=&#8221;8108&#8243; alignment=&#8221;center&#8221; onclick=&#8221;img_link_large&#8221;][vc_column_text]\n<p style=\"text-align: center;\"><strong><em>Fig. 2.\u00a0 Original architecture of the online monitoring system deployed in the Itaja\u00ed substation<\/em><\/strong><\/p>\n[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]The main features of this solution, shown in figure 2, are:<\/p>\n<ul>\n<li>Use of a decentralized architecture, with IED sensors, eliminating the need of a centralized element (PLC or other) in the body of the transformer [4] [5];<\/li>\n<li>IED-type sensors designed and tested specifically for the substation yard environment, ensuring the reliability and durability of the system [4] [5];<\/li>\n<li>Communication between IED sensors and the RS485 monitoring server, shielded twisted pair physical medium;<\/li>\n<li>Conversion of the communication medium RS485 to RS232 for connection to the monitoring server;<\/li>\n<li>Use of an independent monitoring server in the control room of each substation;<\/li>\n<li>Connection of the monitoring server to the Eletrosul corporate network (intranet) to allow users to have remote access to the monitoring system;<\/li>\n<li>Installation of a remote viewing software on each remote user&#8217;s computer connected to the monitoring server.<\/li>\n<\/ul>\n<p>Monitoried variables, according to Eletrosul&#8217;s technical specifications, are in Table 1 [3].[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]\n<p style=\"text-align: center;\"><span id=\"tablepress-170-description\" class=\"tablepress-table-description tablepress-table-description-id-170\">Variables monitored in Itaja\u00ed substation transformers as specified by Eletrosul<\/span>\n\n<table id=\"tablepress-170\" class=\"tablepress tablepress-id-170 tbody-has-connected-cells\" aria-describedby=\"tablepress-170-description\">\n<thead>\n<tr class=\"row-1\">\n\t<th class=\"column-1\"><strong>Variable<\/strong><\/th><th class=\"column-2\"><strong>Sensor<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody class=\"row-striping row-hover\">\n<tr class=\"row-2\">\n\t<td class=\"column-1\">Top oil temperature<\/td><td rowspan=\"5\" class=\"column-2\"><strong>Temperature Monitor<\/strong><\/td>\n<\/tr>\n<tr class=\"row-3\">\n\t<td class=\"column-1\">Winding temperature (hot spot)<\/td>\n<\/tr>\n<tr class=\"row-4\">\n\t<td class=\"column-1\">Ambient temperature<\/td>\n<\/tr>\n<tr class=\"row-5\">\n\t<td class=\"column-1\">Oil temperature at the OLTC load switch <\/td>\n<\/tr>\n<tr class=\"row-6\">\n\t<td class=\"column-1\">Load percentage <\/td>\n<\/tr>\n<tr class=\"row-7\">\n\t<td class=\"column-1\">Oil temperature at the bottom of the tank<\/td><td class=\"column-2\"><strong>Temperature Monitor<\/strong><\/td>\n<\/tr>\n<tr class=\"row-8\">\n\t<td class=\"column-1\">Insulation Capacitance<\/td><td rowspan=\"2\" class=\"column-2\"><strong>Bushing Monitor<\/strong><\/td>\n<\/tr>\n<tr class=\"row-9\">\n\t<td class=\"column-1\">Insulation Tangent Delta<\/td>\n<\/tr>\n<tr class=\"row-10\">\n\t<td class=\"column-1\">Gases dissolved in the oil<\/td><td class=\"column-2\"><strong>Gas Monitor<\/strong><\/td>\n<\/tr>\n<tr class=\"row-11\">\n\t<td class=\"column-1\">Water content dissolved in the transformer oil<\/td><td class=\"column-2\"><strong>Moisture Monitor<\/strong><\/td>\n<\/tr>\n<tr class=\"row-12\">\n\t<td class=\"column-1\">Water content dissolved in the OLTC oil<\/td><td class=\"column-2\"><strong>Moisture Monitor<\/strong><\/td>\n<\/tr>\n<tr class=\"row-13\">\n\t<td class=\"column-1\">Membrane rupture \/ expansion tank bag<\/td><td class=\"column-2\"><strong>Membrane\/ bag rupture relay<\/strong><\/td>\n<\/tr>\n<tr class=\"row-14\">\n\t<td class=\"column-1\">Line voltages<\/td><td rowspan=\"2\" class=\"column-2\"><strong>Digital transducer<\/strong><\/td>\n<\/tr>\n<tr class=\"row-15\">\n\t<td class=\"column-1\">Line currents <\/td>\n<\/tr>\n<tr class=\"row-16\">\n\t<td class=\"column-1\">Fan\/pump voltages<\/td><td rowspan=\"2\" class=\"column-2\"><strong>Digital transducer<\/strong><\/td>\n<\/tr>\n<tr class=\"row-17\">\n\t<td class=\"column-1\">Fan\/pump currents<\/td>\n<\/tr>\n<tr class=\"row-18\">\n\t<td class=\"column-1\">OLTC voltages<\/td><td rowspan=\"2\" class=\"column-2\"><strong>Digital transducer<\/strong><\/td>\n<\/tr>\n<tr class=\"row-19\">\n\t<td class=\"column-1\">OLTC currents<\/td>\n<\/tr>\n<tr class=\"row-20\">\n\t<td class=\"column-1\">OLTC tap position<\/td><td class=\"column-2\"><strong>Tap position indicator<\/strong><\/td>\n<\/tr>\n<tr class=\"row-21\">\n\t<td class=\"column-1\">Cooling stages on \/ off<\/td><td rowspan=\"3\" class=\"column-2\"><strong>Data Acquisition Module<\/strong><\/td>\n<\/tr>\n<tr class=\"row-22\">\n\t<td class=\"column-1\">OLTC operation time<\/td>\n<\/tr>\n<tr class=\"row-23\">\n\t<td class=\"column-1\">Alarm contacts:<br \/>\n- Buchholz relay,<br \/>\n- Pressure relief valve,<br \/>\n- Oil level, etc.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<!-- #tablepress-170 from cache -->\n[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]With these variables, the Sigma software performs data processing to obtain useful information for transformer condition diagnosis and prognosis. Engineering functions, made up of mathematical models and algorithms that peform data processing are shown in Table 2 [3].[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]\n<p style=\"text-align: center;\"><span id=\"tablepress-171-description\" class=\"tablepress-table-description tablepress-table-description-id-171\">Engineering Models for transformer condition diagnosis and prognosis<\/span>\n\n<table id=\"tablepress-171\" class=\"tablepress tablepress-id-171 tbody-has-connected-cells\" aria-describedby=\"tablepress-171-description\">\n<thead>\n<tr class=\"row-1\">\n\t<th class=\"column-1\"><strong>Engineering Model <\/strong><\/th><th class=\"column-2\"><strong>Diagnosis and Prognosis<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody class=\"row-striping row-hover\">\n<tr class=\"row-2\">\n\t<td rowspan=\"3\" class=\"column-1\"><strong>Insulation service life<\/strong><\/td><td class=\"column-2\">Remaining Insulation service life<\/td>\n<\/tr>\n<tr class=\"row-3\">\n\t<td class=\"column-2\">Insulation service life loss trend (% \/ day)<\/td>\n<\/tr>\n<tr class=\"row-4\">\n\t<td class=\"column-2\">Remaining insulation service life (years)<\/td>\n<\/tr>\n<tr class=\"row-5\">\n\t<td rowspan=\"3\" class=\"column-1\"><strong>Temperature final gradient forecast <\/strong><\/td><td class=\"column-2\">Future hot spot temperature after stabilization<\/td>\n<\/tr>\n<tr class=\"row-6\">\n\t<td class=\"column-2\">Time to reach alarm temperature<\/td>\n<\/tr>\n<tr class=\"row-7\">\n\t<td class=\"column-2\">Time to reach shutdown temperature<\/td>\n<\/tr>\n<tr class=\"row-8\">\n\t<td rowspan=\"2\" class=\"column-1\"><strong>Gases dissolved in oil<\/strong><\/td><td class=\"column-2\">Gas in oil evolution trend (mainly H 2)<\/td>\n<\/tr>\n<tr class=\"row-9\">\n\t<td class=\"column-2\">Alarms per evolution trend and high or very high gas concentrations<\/td>\n<\/tr>\n<tr class=\"row-10\">\n\t<td rowspan=\"2\" class=\"column-1\"><strong>Chromatography \/ Physicochemical<\/strong><\/td><td class=\"column-2\">Gas chromatography offline test reports<\/td>\n<\/tr>\n<tr class=\"row-11\">\n\t<td class=\"column-2\">Physicochemical offline test reports<\/td>\n<\/tr>\n<tr class=\"row-12\">\n\t<td rowspan=\"5\" class=\"column-1\"><strong>Moisture in oil and on paper<\/strong><\/td><td class=\"column-2\">Transformer sealing - expansion tank rubber bag rupture<\/td>\n<\/tr>\n<tr class=\"row-13\">\n\t<td class=\"column-2\">Water content in oil (ppm)<\/td>\n<\/tr>\n<tr class=\"row-14\">\n\t<td class=\"column-2\">Trend in water content evolution (ppm \/ day)<\/td>\n<\/tr>\n<tr class=\"row-15\">\n\t<td class=\"column-2\">Water content in paper (% dry mass)<\/td>\n<\/tr>\n<tr class=\"row-16\">\n\t<td class=\"column-2\">Insulation service life loss acceleration factor through hydrolysis<\/td>\n<\/tr>\n<tr class=\"row-17\">\n\t<td rowspan=\"2\" class=\"column-1\"><strong>Bubble formation temperature <\/strong><\/td><td class=\"column-2\">Bubble formation temperature<\/td>\n<\/tr>\n<tr class=\"row-18\">\n\t<td class=\"column-2\">Free water formation temperature<\/td>\n<\/tr>\n<tr class=\"row-19\">\n\t<td rowspan=\"3\" class=\"column-1\"><strong>Cooling efficiency<\/strong><\/td><td class=\"column-2\">Top oil calculated temperature<\/td>\n<\/tr>\n<tr class=\"row-20\">\n\t<td class=\"column-2\">Difference between measured and calculated temperatures<\/td>\n<\/tr>\n<tr class=\"row-21\">\n\t<td class=\"column-2\">Cooling system efficiency<\/td>\n<\/tr>\n<tr class=\"row-22\">\n\t<td rowspan=\"3\" class=\"column-1\"><strong>OLTC temperature differential<\/strong><\/td><td class=\"column-2\">Instant temperature differential<\/td>\n<\/tr>\n<tr class=\"row-23\">\n\t<td class=\"column-2\">Filtered temperature differential<\/td>\n<\/tr>\n<tr class=\"row-24\">\n\t<td class=\"column-2\">Differential temperature high alarms<\/td>\n<\/tr>\n<tr class=\"row-25\">\n\t<td rowspan=\"3\" class=\"column-1\"><strong>Torque and OLTC motor operation time<\/strong><\/td><td class=\"column-2\">Maximum torque of the motor in each commutation region<\/td>\n<\/tr>\n<tr class=\"row-26\">\n\t<td class=\"column-2\">OLTC mechanism operation time<\/td>\n<\/tr>\n<tr class=\"row-27\">\n\t<td class=\"column-2\">Out-of-standard alarms per torque values and operation time <\/td>\n<\/tr>\n<tr class=\"row-28\">\n\t<td rowspan=\"5\" class=\"column-1\"><strong>OLTC maintenance assistant<\/strong><\/td><td class=\"column-2\">Commuter operation number<\/td>\n<\/tr>\n<tr class=\"row-29\">\n\t<td class=\"column-2\">Commuted current sum<\/td>\n<\/tr>\n<tr class=\"row-30\">\n\t<td class=\"column-2\">OLTC operation time<\/td>\n<\/tr>\n<tr class=\"row-31\">\n\t<td class=\"column-2\">Forecast of remaining time before the next OLTC maintenance <\/td>\n<\/tr>\n<tr class=\"row-32\">\n\t<td class=\"column-2\">Early OLTC maintenance warnings<\/td>\n<\/tr>\n<tr class=\"row-33\">\n\t<td rowspan=\"3\" class=\"column-1\"><strong>Forced ventilation maintenance wizard <\/strong><\/td><td class=\"column-2\">Ventilation group operation time, total and after the last maintenance.<\/td>\n<\/tr>\n<tr class=\"row-34\">\n\t<td class=\"column-2\">Forecast of the remaining time before ventilation maintenance.<\/td>\n<\/tr>\n<tr class=\"row-35\">\n\t<td class=\"column-2\">Early Ventilation maintenance warnings<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<!-- #tablepress-171 from cache -->\n[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]Later, this same solution has expanded to 27 (twenty seven) other Eletrosul transformers and reactors. Table 3 lists all monitored pieces of equipment.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]\n<p style=\"text-align: center;\"><span id=\"tablepress-174-description\" class=\"tablepress-table-description tablepress-table-description-id-174\">Sigma monitoring systems installed at Eletrosul<\/span>\n\n<table id=\"tablepress-174\" class=\"tablepress tablepress-id-174\" aria-describedby=\"tablepress-174-description\">\n<thead>\n<tr class=\"row-1\">\n\t<th class=\"column-1\"><strong>Substation<\/strong><\/th><th class=\"column-2\"><strong>Transformers<\/strong><\/th><th class=\"column-3\"><strong>Reactors<\/strong><\/th><th class=\"column-4\"><strong>Voltage (kV)<\/strong><\/th><th class=\"column-5\"><strong>Power<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody class=\"row-striping row-hover\">\n<tr class=\"row-2\">\n\t<td class=\"column-1\">Itaja\u00ed<\/td><td class=\"column-2\">3<\/td><td class=\"column-3\">0<\/td><td class=\"column-4\">230\/138 - 13,8<\/td><td class=\"column-5\">150MVA<\/td>\n<\/tr>\n<tr class=\"row-3\">\n\t<td class=\"column-1\">Sider\u00f3polis<\/td><td class=\"column-2\">1<\/td><td class=\"column-3\">0<\/td><td class=\"column-4\">230\/69 - 13,8<\/td><td class=\"column-5\">88MVA<\/td>\n<\/tr>\n<tr class=\"row-4\">\n\t<td class=\"column-1\">Xanxer\u00ea<\/td><td class=\"column-2\">2<\/td><td class=\"column-3\">0<\/td><td class=\"column-4\">230\/138 - 13,8<\/td><td class=\"column-5\">150MVA<\/td>\n<\/tr>\n<tr class=\"row-5\">\n\t<td class=\"column-1\">Campos Novos<\/td><td class=\"column-2\">6<\/td><td class=\"column-3\">0<\/td><td class=\"column-4\">525\/230 - 13,8<\/td><td class=\"column-5\">224MVA<\/td>\n<\/tr>\n<tr class=\"row-6\">\n\t<td class=\"column-1\">Bigua\u00e7u<\/td><td class=\"column-2\">2<\/td><td class=\"column-3\">0<\/td><td class=\"column-4\">230\/138 - 13,8<\/td><td class=\"column-5\">150MVA<\/td>\n<\/tr>\n<tr class=\"row-7\">\n\t<td class=\"column-1\">Gravata\u00ed III<\/td><td class=\"column-2\">4<\/td><td class=\"column-3\">0<\/td><td class=\"column-4\">230\/69 - 13,8<\/td><td class=\"column-5\">55MVA<\/td>\n<\/tr>\n<tr class=\"row-8\">\n\t<td class=\"column-1\">Nova Santa Rita<\/td><td class=\"column-2\">3<\/td><td class=\"column-3\">0<\/td><td class=\"column-4\">525\/230 - 13,8<\/td><td class=\"column-5\">224MVA<\/td>\n<\/tr>\n<tr class=\"row-9\">\n\t<td class=\"column-1\">Santo \u00c2ngelo<\/td><td class=\"column-2\">3<\/td><td class=\"column-3\">3<\/td><td class=\"column-4\">525\/230 - 13,8<br \/>\n550 (reactor)<\/td><td class=\"column-5\">224MVA<br \/>\n54MVAr<\/td>\n<\/tr>\n<tr class=\"row-10\">\n\t<td class=\"column-1\">Dourados<\/td><td class=\"column-2\">1<\/td><td class=\"column-3\">0<\/td><td class=\"column-4\">230\/138 - 13,8<\/td><td class=\"column-5\">75MVA<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<!-- #tablepress-174 from cache -->\n[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;3.0 &#8211; EVOLUTION OF ONLINE MONITORING SYSTEMS&#8221; element_type=&#8221;h2&#8243; span_background=&#8221;#008242&#8243; span_color=&#8221;#008242&#8243;][\/vc_column][\/vc_row][vc_row][vc_column]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]Naturally, because at the time of the early implementation (2001), this was a new technology, the Sigma system underwent a process of evolution in which Eletrobras Eletrosul played an important role in interacting with new developments, enhancements and customizations performed in the system.<\/p>\n<p>In this process the system was customized to meet Eletrobras&#8217;s specific needs, like the inclusion of a proprietary diagnostic algorithm through gas chromatography as well as improvements to facilitate the usability of the system. The following are some system evolution examples:[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;3.1 &#8211; Customizing a method for DGA diagnosis for Eletrosul&#8221; element_type=&#8221;h2&#8243; span_background=&#8221;#008242&#8243; span_color=&#8221;#008242&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]The analysis of gas chromatography test results takes place at Eletrosul through a proprietary methodology developed as a result of the company&#8217;s experience with this technique. Due to the fact the monitoring software is open it allows the addition of new monitoring functions by the user, which was done with this Eletrosul proprietary gas-chromatography technique.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;3.2 &#8211; System expansions&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]Taking advantage of the characteristics of modularity and expandability of the Sigma system, and of the fact that it is an open system, expansions have been included to add other sensors.<\/p>\n<p>IED sensors were initially added to the system to perform online monitoring of bushing capacitance and tangent delta since those sensors were installed on the transformer in a posterior step.<\/p>\n<p>Later, several online sensors were added to the system to detect gas dissolved in oil (primarily H<sub>2<\/sub>); those sensors were already installed in the Eletrosul transformer park. In this case, the fact that the system is open to the development of a specific communication driver for those sensors, which used a factory proprietary communication protocol, was also an advantage. Since the sensors were in other company substations, we used the Eletrosul Intranet to send data from these sensors to the monitoring server in the Itaja\u00ed substation control room.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;3.3 &#8211; Sending e-mail alerts&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]To eliminate the need for an operator to continually oversee the system, an e-mail capability was added to the system so messages are automatically sent to previously registered addresses. This prevents wasting the maintenance engineers\u2019 time during periods in which no problems are diagnosed.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;3.4 &#8211; Upgrading with Web 2.0 technologies&#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]As explained in section 2.0, the system as it was initially deployed in Eletrosul used a viewing software to remotely access the data. This viewing software had to be installed in each user&#8217;s remote computer.<\/p>\n<p>This solution, while functionally perfect, was inconvenient in some aspects, such as limiting access to the system to previously prepared computers, the waste of computer engineer time to install the viewing software for the users and also to download the necessary updates.<\/p>\n<p>To avoid these inconveniences, and in line with the most modern cloud-computing trends, in which the applications are executed only in remote servers, using as local interface only the internet browser, the Sigma monitoring interface has been updated to use the so called Web 2.0 technologies.<\/p>\n<p>Thus, there is no longer need to install specific software on users&#8217; computers; the users now use only their internet browser. Therefore, any upgrades to the system are restricted to the monitoring servers, and do not affect the user computers. The access to the system is possible from any computer in the Eletrosul Intranet, as long as the user has a user ID and a password.<\/p>\n<p>System access security can be preserved through the cryptographed connection protocol HTTPS, in addition to the login and password to access the system.[\/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;3.5 &#8211; Wireless communication with the sensors&#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]In order to reduce the cost and facilitate the installation of monitoring systems, the feasibility of using wireless communications between sensors on the transformer and the substation control room has been verified by a pilot in Santo \u00c2ngelo substation, at the time the system was installed in a transformer bank, using the Wi-fi standard.\u00a0 Gas sensors which were already in place were integrated as well as new bushing capacitance and tangent delta monitors.\u00a0 Data are directly transmitted to a router connected to the corporate network and acquired by the Sigma 4 software.<\/p>\n<p>The application performance proved entirely satisfactory, demonstrating the feasibility of this technology with great potential to reduce costs and installation time.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;3.6 &#8211; Adding an Engineering Model&#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]The open and modular architecture of the monitoring system has also allowed the inclusion of a new engineering item for loading simuation. The simulation is possible in two ways:<\/p>\n<ul>\n<li>Based on current load conditions at ambient temperature, with the user inserting the new hypothetical loading value;<\/li>\n<li>Based on hypothetical load evolution curves and ambient temperature in 24 hours.<\/li>\n<\/ul>\n<p>In both modes the user can see the consequences of hypothetical situations in terms of temperatures reached and loss of life related, and can compare the maximum temperature that would be achieved with the temperature of bubble formation due to moisture, also calculated by the monitoring software. In all simulations, the user can modify the cooling command mode (automatic or manual) and the enabling temperatures, as well as the cooling hysteresis.[\/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;3.7 &#8211; Connectivity to other systems&#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 evolution of the Sigma monitoring systems has provided them with a capability to exchange data with other Eletrosul systems, such as the SAGE supervising system.<\/p>\n<p>This connectivity is possible through different methods, selected according to the need and convenience of the application. Examples of possibilities are SQL databases or, in other standards, OPC, web services, open communication protocols (eg Modbus, DNP 3.0, TCP \/ IP), among others.[\/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;4.0 &#8211; RESULTS&#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 use of automated online monitoring of transformers and reactors has several features that may be beneficial for the maintenance of that kind of equipment, such as reducing risk of catastrophic failure, controlling and extending service life, migrating from preventive to predictive maintenance, with the consequent increase in the availability of the equipment and reduction of the costs due to lack of equipment availablity, among others.<\/p>\n<p>However, the monitoring system is presented as a useful tool not only for maintenance engineering but also for the operation and planning, due to loading simulation and prediction of future temperature as a function of current load, associated with equipment status diagnoses, which provide an indication of the risk to use overloaded equipment, for example.<\/p>\n<p>Another example of the usefulness of the monitoring system could be observed when a 245 kV bushing failed in the Santo \u00c2ngelo substation. In this case, the evolution of the bushing defect was extremely fast, leaving no time to remove it from operation before failure, unlike what is normally expected for defects in bushings [6]. However, the presence of the monitoring system with the storage of measurements in databases allowed further analysis of the occurrence, leading to conclusions that would be impossible without the monitoring system &#8211; like the fact that the defect evolved very quickly.<\/p>\n<p>Therefore, the monitoring system allowed the technicians to deepen their knowledge about the evolution of this type of defect and to improve the system itself and the procedures when this kind of defect takes place.[\/vc_column_text]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_text_separator title=&#8221;5.0 &#8211; CONCLUSIONS&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[\/vc_column_inner][\/vc_row_inner][vc_row_inner][vc_column_inner][vc_column_text]This paper has presented the history of installation, expansion, customization and operation of the Sigma monitoring systems in Eletrobras Eletrosul, as well as the evolution of this system over time, including the architectures used to install sensors on the equipment, data output architectures, communication media and user interfaces.<\/p>\n<p>The results obtained were presented as well as the benefits gained with the developments and improvements of the system over time, mostly allowed by Sigma&#8217;s open, decentralized and modular architecture.<\/p>\n<p>Considering the importance of transformers and reactors in the Eletrosul park for the SIN, the installation of the online monitoring system for that equipment, as well as the possibility of the system evolution and of its uses over time is of great significance to increase the electric power system reliability and the supply continuity, in addition to contributing to cost reductions that help to reduce rates.[\/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;6.0 &#8211; REFERENCES&#8221; element_type=&#8221;div&#8221; span_color=&#8221;#008842&#8243;]<div class=\"vcex-spacing wpex-w-100 wpex-clear\"><\/div>[vc_column_text]\n<ol>\n<li>Amom, Jorge, Alves, Marcos, Vita, Andr\u00e9, Kastrup Filho, Oscar, Ribeiro, Adolfo, et. al., \u201cSistema de Diagn\u00f3sticos para o Monitoramento de Subesta\u00e7\u00f5es de Alta Tens\u00e3o e o Gerenciamento das Atividades de Manuten\u00e7\u00e3o: Integra\u00e7\u00e3o e Aplica\u00e7\u00f5es\u201d, X ERLAC &#8211; Encontro Regional Latinoamericano do CIGR\u00c9, Puerto Iguazu, Argentina, 2003.<\/li>\n<li>Alves, Marcos, \u201cSistema de Monitora\u00e7\u00e3o On-Line de Transformadores de Pot\u00eancia\u201d, Revista Eletricidade Moderna, Maio\/2004.<\/li>\n<li>Alves, Marcos, \u201cField Experience with On-Line Monitoring of Two 150MVA 230kV Transformers with On-Load Tap Changers\u201d, Cigre SC A3 International Technical Colloquium, September\/2007.<\/li>\n<li>Vasconcellos, M. Alves, \u201cEspecifica\u00e7\u00e3o de Sistemas de Monitora\u00e7\u00e3o On-line para Transformadores de Pot\u00eancia Baseados em uma Arquitetura Descentralizada&#8221;, V Workspot, Brasil, Abril 2008.<\/li>\n<li>Lavieri Jr., Arthur, Hering, Ricardo, \u201cNovos Conceitos em Sistemas de Energia de Alta Confiabilidade\u201d, Encarte Especial Siemens Energia, http:\/\/ mediaibox.siemens.com.br\/upfiles\/232.pdf, Janeiro\/2001.<\/li>\n<li>Melo, Marcos A. C., Alves, Marcos, \u201cExperi\u00eancia com Monitora\u00e7\u00e3o On-Line de Capacit\u00e2ncia e Tangente Delta de Buchas Condensivas\u201d, XIX SNPTEE \u2013 Semin\u00e1rio Nacional de Produ\u00e7\u00e3o e Transmiss\u00e3o de Energia El\u00e9trica. Rio de Janeiro, Brasil, 2007.<\/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 High voltage assets in substations, such as transformer and reactors, are crucial for the safe operation and continuity of the electric power supply. Consequently online monitoring systems have been used to increase the reliability and availability of those pieces of equipment, and at the same time, to reduce costs.\u00a0 Eletrobras Eletrosul started&hellip;<\/p>\n","protected":false},"author":1,"featured_media":5381,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[139],"tags":[],"class_list":["post-8109","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-transmission","entry","has-media"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/posts\/8109","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=8109"}],"version-history":[{"count":0,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/posts\/8109\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/media\/5381"}],"wp:attachment":[{"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/media?parent=8109"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/categories?post=8109"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/treetech.com.br\/en\/wp-json\/wp\/v2\/tags?post=8109"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}