1.6 inches = 1.6 inches x 1,000 mils per inch = 1,600 mils 0.25 inch = 0.25 inch x 1,000 mils per inch = 250 mils Area = 1,600 x 250 = 400,000 square mils
Dielectric faults occur in the winding due to turn-to-turn insulation breakdown. It is the insulation between the turns of the winding. Insulation breakdown commonly occurs due to high current and voltage which are high above the rated values. The breakdown of the insulation results in the flashover of the winding turns and cause a short circuit.
Deterioration of oil may occur due to the result of prolonged overloading of the transformer. Excessive oil temperature produces the formation of sludge, water, and acids. Moisture entering the oil as a result of the breathing action greatly reduces its dielectric strength so that breakdown from coils or terminal leads to tank or core structure may take place.
Dynamic voltage restoration (DVR) is a method of overcoming voltage sags and swells that occur in electrical power distribution. Devices used for DVR include static var devices, which are series compensation devices that use voltage source converters (VSC). The DVR is used to inject three phase voltage in series and in synchronism with the network voltages in order to compensate voltage disturbances with a benefit of active /reactive power control.
EXAMIANS