Dry Cast Resin Transformers: High-Altitude Adaptation Models

A:Reasons: Loosening of core, deformation of windings, resonance of components, failure of cooling system, influence of grid harmonics. Measures: Tighten the core clamps; Correct the position of windings; Adjust the shock absorption devices of cooling fans / oil pumps; Install soundproof covers; Address grid harmonics.

A:Minor leakage: Tighten the flange bolts of the casing and replace the sealing gasket; Severe leakage: Replace the casing after power outage; If the insulation inside the casing gets damp, conduct an insulation test and replace the casing if necessary.

A:The load rate has consistently exceeded 80% and there have been frequent overloads; the losses under no-load and at full load are more than 20% above the standard; insulation has aged (with excessive dielectric loss values and deteriorated oil quality); serious faults have occurred (such as winding deformation and multiple-point grounding of the core); the energy efficiency grade is lower than level 3 and energy-saving renovations are not economically viable; it has reached the design service life (generally 20–30 years).