The iron core transformer fault analysis - 2019
30 15:05:35 iron core transformer fault is mainly in the transformer core body winding and insulation failure.
Performance in all parts of the insulation aging, winding be affected with damp be affected with damp, winding layers, turn-to-turn, alternate with, occur between high and low voltage winding grounding, short circuit, open circuit, breakdown or burned down;
The system short-circuit winding mechanical damage;
Impact current winding mechanical damage, etc.
The iron core transformer fault mainly has three kind of 1)
Interturn short circuit fault cause of turn-to-turn short circuit usually have: transformer iron core coil making improper operation, turn-to-turn insulation damage;
Turn insulation of the wire is not enough, higher interturn working field strength, tolerance to resist the action of working voltage for a long time or short impulse voltage, long running insulation aging, deformation, crunchy;
Local high temperature oil flow caused by blind Angle or oil duct jam for accelerated insulation aging;
The role of the electric power to move a axial line turn part of live, cause insulation wear and form through the short circuit, overload running for a long time under the winding line overheat and insulate brittle;
Under the action of all sorts of overvoltage and overcurrent, insulation performance degradation;
Electrical failure caused such as partial discharge windings turn-to-turn short circuit;
The casing of oil and make the winding leakage of oil level, less deterioration in cooling and overheating will form a winding short circuit.
Line-to-line fault in small and medium sized transformer core, two phase coil wire and soft copper wire touching on the interphase short circuit caused more;
In large transformer core, if by chance, such as wire conductor, will also turn insulation cut, constitute two phase line short circuit;
When tap-changer dislocation seriously, will lead to two phase tap-changer short circuit and burn out, and two phase winding short circuit.
Short circuit fault between shares in multi-strand wire and around the iron core transformer often occur between stocks short circuit, the main reasons are: insulating layer surrounding the inequality caused by wire quality problems, even lead exposed;
Due to the bending in the process of winding, burr and so on make the turn-to-turn insulation damage, improper card line too close or transposition in line twist wring or scratch wire insulation;
In the process of pressure equipment and plastic, squeeze and insulation between the winding wire.