- Asked 2/22
- 2072 Chaitra · 6 marks
- 2079 Baisakh · 4 marks
Parts of a power transformer
Short answer
Core provides low-reluctance flux path; windings induce voltage; oil insulates and cools; conservator handles oil expansion; breather with silica gel dries incoming air; Buchholz relay detects gas from faults; radiators/fans dissipate heat; bushings insulate leads; tap changer adjusts turns ratio; OTI/WTI monitor temperature.
Explain the function of various parts of a power transformer with a neat sketch.
A power transformer transfers power between two voltage levels by mutual induction. Besides the core and windings it has many accessories for cooling, protection and voltage control.
HV bushing LV bushing conservator
| | | | +---------+--breather
| | | | | oil | (silica gel)
vent _|__|________|__|_____+----+----+
===> | oil-filled tank | Buchholz relay
| +--------------------+ |
| | core + HV/LV wndgs | |=== radiators
| +--------------------+ |
| tap changer OTI WTI |
+---------------------------+
drain valve earthing
Parts and functions
| Part | Function |
|---|---|
| Core (CRGO laminations) | Low-reluctance path for flux; laminated to cut eddy loss |
| HV and LV windings (copper) | Carry current; induce voltage in ratio of turns |
| Tank | Holds core, windings and oil; mechanical protection |
| Transformer oil | Insulation and cooling medium |
| Conservator | Takes up oil expansion and contraction; keeps main tank full |
| Breather (silica gel) | Dries the air entering the conservator |
| Buchholz relay | Gas-operated relay between tank and conservator; alarms/trips for internal faults |
| Explosion vent / pressure relief valve | Releases sudden high pressure during severe internal faults |
| Radiators, fans, pumps | Remove heat (ONAN, ONAF, OFAF cooling) |
| Bushings | Bring winding leads out through the tank with insulation |
| Tap changer (on-load/off-load) | Changes turns ratio to control voltage |
| Oil and winding temperature indicators (OTI, WTI) | Show temperature; give alarm and trip, start fans |
| Oil level indicator | Shows oil level in conservator |
| Drain and filter valves | Draining, sampling and filtering oil |
✓ Answer checked by Claude Opus 5.5 (high effort)
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