Hello learners, welcome to this module on transformer and reactor protection. Let's start with the topic on protection requirements of transformers. At the end of this topic, you should be able to state the need of transformer protection, list the causes and reasons of transformer failure. Let's begin with an introduction to transform of protection. When compared to mistakes in generators or other power system components, transformer failures are uncommon. If a transformer failure is not rectified, it can cause a severe damage with a lengthy repair time. The average repair outage time is longer than that of the majority of other components. The cost of repairing the damage to transformers is cost due to production failure are lost. The spread of damage to nearby equipment has a negative impact on the system's overall balance. The time it takes for damaged equipment to become available again. During operation, the electrical winding and magnetic core of a transformer are subjected to a variety of forces. Expansion and contraction are caused by thermal cycling. Vibration, local heating is caused by magnetic flux. As a result of overloaded or insufficient cooling, there is excessive heating, forces exerted by currents flowing across faults. Let us have a look at the following reasons for transformer failure at windings, on Load Tap Changers, bushings, problems at the core, miscellaneous. Faults and bindings are due to number of issues. Deterioration of insulation as a result of moisture, overheating, vibration, surges in voltage, through-faults cause mechanical stress. The following faults may occur an on Load Tap Changer failure of the mechanical switching mechanism, contacts with the high resistance, overheating, insulating oil contamination. The following are the issues with bushings, accumulation of dust, cracking, moisture on the inside, aging. The following are the core issues failure of the core insulation, ground strap is unfastened, laminations that our short circuited, overheating in the core. Miscellaneous problems are CT issues, oil leakage, oil contamination, metal particles moisture. Probable reasons for transformer failures and their solutions are shown in the screen. Let us summarize all that you have learned. Provided an explanation for the necessity of transformer protection. Transformer failures owing to falls in the winding, LTC', bushings, core, and other unspecified causes were discussed.
