AN IMPROVED POWER TRANSFORMER WITH VACUUM TYPE ON LOAD TAP CHANGER (OLTC) OPERABLE AT AN OIL-HEAD EXCEEDING TEN METERS

摘要

The invention relates to an improved power transformer with vacuum type on load tap changer (OLTC) operable at an oil-head exceeding ten meters, comprising a magnetic core, a high-voltage (HV) winding, a set of a low-voltage (LV) winding, a transformer tank, and a vacuum type on load tap changer (OLTC); and a conservator (C) disposed at a height exceeding ten meters above the transformer tank, the transformer tank is configured into two halves, the first half accommodating the magnetic core-coil assembly and the second half housing the vacuum OLTC, the two halves being separated by a steel wall (W) having a plurality of cut-outs, the cut- outs provided with insulated terminal board (TB) with corresponding numbers of terminal bushings (B) allowing connection between the coils and the OLTC, and in that the second half is smaller in size than the first half and provided with an auxiliary conservator (AC) leading to maintaining of oil-head pressure on the vacuum OLTC is the range of 0.1 kg/sq.cm which is equivalent to 1 meter oil head.