The technical problems to modify low voltage winding of power transformer

The transformer is the main equipment in the electrical power systems to convert the potential from low voltage to high voltage or on the contrary. To build the real new transformer is easier than rewind and modify the old one, because have many technical constrains for solving these problems. The old transformer has the fix dimension for example length, width, depth of the casing and dimension of the magnetic core. The capacity and the high voltage of the “new” transformer still same with the old one is 20 MVA but only the low voltage is changed from 6 KV to 13.8 KV. The first step before modify the old transformer, we have to know well about the condition of this transformer by checked / measured the all electrical quantity. The detail calculation and construction of the low voltage winding with many constrain must be done well. After that to choice the material especially the wire for low voltage winding include the type of insulation, to make schedule and standard operation procedure of construction. At the last to test the vector group of voltage and to test all of electrical quantity include the energy losses of the “new” transformer.