Transformer winding deformation refers to the irreversible changes in the size and shape of the winding under the action of machinery and electricity. It includes changes in axial and radial dimensions, body displacement, winding twist, bulging and inter-turn shorts, etc. The reason is that the transformer inevitably has to withstand various short-circuit shocks and short-circuits at the outlet during operation. Especially harmful to transformers.
HV Hipot GDRB-B Transformer Frequency Response Analyzer
Although the circuit breaker can quickly eliminate the short-circuit fault in the circuit, the automatic device often does not operate for some reason, so that the transformer coil is deformed in a very short period of time under the action of the short-circuit current heat, electricity, and even serious interphase short-circuit and The winding is burnt; at the same time, the transformer may also be bumped and impacted during transportation and installation, resulting in deformation, broken strands, displacement, loosening and other phenomena.
What is the purpose of transformer winding deformation test?
A: Winding deformation is a major hidden danger to the safe operation of power systems. In recent years, with the increase of the capacity of the power system, the short-circuit capacity is also increasing, and the winding damage accident caused by the short-circuit of the outgoing line is also on the rise.
After the transformer winding is deformed, the first is the change of the insulation distance or the damage of the insulation paper. When overvoltage is encountered, the windings will have inter-cake or inter-turn breakdown, or under the action of long-term working voltage, the insulation damage will gradually expand, eventually leading to the transformer. Damage: Second, after the winding is deformed, the mechanical properties decrease. When a short circuit accident occurs again, because it cannot withstand the huge impact force, an immediate damage accident will occur, and it can still operate for a period of time.
Transformer winding deformation is one of the important reasons for transformer damage. Conventional electrical tests such as resistance measurement, transformation ratio measurement, and capacitance measurement are difficult to find winding deformation, which will seriously threaten the safe operation of the power grid. For this reason, it is very necessary to detect and diagnose the deformation of transformer windings subjected to mechanical and electrical forces.
Post time: Jun-13-2022