{"id":1598,"date":"2014-08-04T09:21:13","date_gmt":"2014-08-04T09:21:13","guid":{"rendered":"http:\/\/gcequipment.com\/?p=1598"},"modified":"2016-07-15T08:37:33","modified_gmt":"2016-07-15T08:37:33","slug":"dielectric-strength-of-transformer-oil-2","status":"publish","type":"post","link":"https:\/\/oilregeneration.globecore.com\/dielectric-strength-of-transformer-oil-2","title":{"rendered":"Dielectric Strength of Transformer Insulating Oil"},"content":{"rendered":"

Dielectric<\/strong> Strength of Transformer Oil<\/strong><\/em><\/h2>\n

CMM in ELKIMA\u00a0 transformer was successfully tested<\/h2>\n
\"Good<\/a>

After oil processing by our equipment series CMM in ELKIMA\u00a0 transformer was successfully tested<\/p><\/div>\n

The Dielectric Strength<\/strong><\/em> of transformer oil is very important since it is essential in maintaining the reliable operation of power transformers.\u00a0 The dielectric strength of transformer oil is mainly determined by the presence of acids, water, and other contaminates.\u00a0 It is therefore, important to keep the transformer oil as free from such contaminates as possible.\u00a0 The dielectric strength of the oil will decrease with time and based on the service conditions where the transformer is located.<\/p>\n

The Dielectric strength of oil<\/strong><\/em> is extremely sensitive to hydration or introduction of water and moisture.\u00a0 Under the action of the electric field of the emulsified oil, droplets of water are drawn to places where the field strength is particularly high. \u00a0 This process begins the process of oil breakdown.\u00a0 There can be an even more dramatic reduction of dielectric strength when the oil becomes contaminated by other impurities other than water such as acids and particulate matter. Some particulate matter, in the form of fibers, can become arranged in the form of lines known as “lines of force.”\u00a0 Under the influence of the field forces, the wet fibers are not only drawn into places where the field is stronger, but become arranged in a way that greatly facilitates the breakdown of the transformer oil.<\/p>\n

The Dielectric strength<\/em><\/strong> of transformer oil is also known as the breakdown voltage of the transformer oil.\u00a0 “Breakdown Voltage”<\/em><\/strong> (BDV) is measured by observing the voltage that is required to jump a spark between two electrodes immersed in the oil separated by a specific gap or distance.\u00a0 Also known as the sparking strength, the higher the voltage required to jump the spark, the higher the BDV will be in the oil.\u00a0 The lower the voltage required to jump the spark, the BDV will be lower indicating\u00a0 the presence of moisture content and other conducting substances in the oil.<\/p>\n

Clean oil with a low moisture content gives higher BDV results than oil with high moisture content and other conducting impurities.\u00a0 A rating of 30 kV is the minimum breakdown voltage at which transformer oil can be safely used in a power transformer.<\/p>\n

Dielectric strength<\/strong><\/em> of oils is also determined by the dielectric loss tangent or “Tan Delta.”\u00a0 As stated above, dielectric strength of transformer oil is mainly determined by the presence of acids, water, and other contaminates in the oil.\u00a0\u00a0 Another important factor in oil performance, is the low temperature “pour point.<\/em><\/strong>”\u00a0 A low temperature pour point of -45\u00b0C and below is necessary for allowing oil to flow at extremely cold temperatures.<\/p>\n

Operational properties of transformer oils are checked by electrical insulating and physico- chemical characteristics :<\/p>\n