Abstract:
This thesis presented the development of oil-immerse type large distribution transformer cost design using an area eilimination technique which had rate of 1000 20000 kVA,
3 phases, 50 Hz, primary voltage 11000 33000 V., secondary voltage 3300 11000 V., Dyn_11. The construction of primary winding was disc coil using rectangular copper
wire, secondary winding, also disc coil using rectangulary copper wire. In research, to change parameter from the range of variable to get the suitable parameter of each variable
consisted of the guarantee no-load loss, load loss and short circuit impedance, which had the limitation of temperature gradient. The characteristics of optimal transformer design
were also compared with industrial design. The prototype transformer ( 8000 kVA, 3 phase, 50 Hz, Primary voltage 22000 V., secondary voltage 3300/1905 V. primary tap +2,-2
*2.5%, Dyn_11.) were manufactured according to the optimal cost design result of large distribution transformer and tested in laboratories. The test results were within guarantee
limitation. Furthermore, either the design parameters or the limit of specification of distribution transformers was varied to find the optimal cost. With this regards, the design
procedure of distribution transformers at desire characteristic and minimize total cost were achieved.