Abnormal sound of traction transformer and its treatment

I. Phenomenon:

Abnormal transformer sound

Second, the reason:

a) Overvoltage, overload, or large capacity electric locomotive startup.

b) Loosen resonance noise in the traction transformer with loose parts.

c) Abnormal sound caused by external discharge.

d) Internal faults in the traction transformer or insulation breakdown discharge.

e) Discharge sound caused by climate impact.

f) Short circuit between turns.

g) The tap switch is in poor contact.

Third, deal with:

a) The traction transformer is evenly humming during normal operation. Observe the overload of the instrument.

Pressure conditions are indeed overvoltage or overload, depending on the load conditions in accordance with the provisions of the manufacturer or the regulations allow overload operation time, while checking whether the oil temperature cooling device is normal. Or apply for a load reduction to the ESC. But it is still buzzing. It's just bigger than the original, and it has no noise. However, it is also possible that with the rapid changes in the load, the gap between the "cutting, cutting, cutting, and cutting" assaults will appear. The sound moves with the voltage meter (voltmeter, ammeter) pointer of the transformer.

b) Loosening of the screws that clamp the iron core, and the noise caused by this cause presents an astonishing "hammer" and "big wind" sound. Such as "Ding DingDang" and "Call ... ... call ... ... sound. But the indicator is normal, oil color, oil temperature, oil level are normal.

c) caused by the impact of the transformer shell on other objects. This is because the vibration of the inner core of the traction transformer causes vibrations of other components, causing the contacts to collide with each other. For example, the hose of the control line on the transformer collides with the housing or the radiator, and the sound of “shashasha” appears. The characteristics are continuous and long, and the gap does not appear abnormal in all parts of the transformer. At this time, you can search for the sound source, and use the hand or wooden stick on the sinful side to hear the change in the sound and identify the difference.

d) Discharge sound caused by external climate influences. Such as heavy fog days, snow days, snow days caused the corona discharge or glow discharge at the casing, showing the sound of “嘶嘶” and “嗤嗤”, and visible blue spark at night.

e) Core failure. If the grounding wire of the core is disconnected, it will produce a buzzing sound such as discharge, and the “iron core will catch fire” will cause abnormal sound

Short circuit between turns. Due to the severe local heating at the short circuit, the partial boiling will make a "squeaky" sound. This kind of voice should pay special attention.

f) Failure of tap changer. Due to poor contact of the tap-changer, local heating can also cause sounds like short circuits between turns.