Power transformer is an important guarantee for power grid operation. The stability and reliability of voltage transformer are very important for the safety of power system. Transformers in the design and manufacture of the time, due to manufacturing technology and processes, and in the course of the use of the work is not well maintained, is easily lead to transformer failure. Nowadays, people pay much attention to the short-circuit fault of the transformer. The short-circuit of the transformer is very easy to affect the safe operation of the power system. Transformer failure analysis of the past, a large part of the reason is short-circuit caused by the transformer, in order to avoid transformer failure, we must reduce the transformer short-circuit situation.
1, the short-circuit transformer damage
When the power system is running, once the transformer short-circuit situation will lead to the power system in the operational security there are risks. The reason why there will be short-circuit transformer, mainly in the electric power and mechanical forces of the common role, the transformer winding may be deformed in the transformer winding deformation occurs, and sometimes may soon be damaged Accidents, and most cases, the transformer will still run for a long time, the length of the transformer running time is mainly determined by the severity of the winding deformation and deformation of the site. Transformer in the winding deformation occurs after the normal work is extremely vulnerable to failure. This is because, first of all, the winding deformation occurs, the mechanical properties of the winding will be reduced, when the winding again by the impact of short-circuit current, it is very likely to not withstand the impact of a huge power, and then damage the accident. Second, after the deformation of the winding may occur transformer insulation performance changes, is likely to lead to the partial discharge of the transformer, in this case, if there is no time to find that the transformer in the long run , The partial discharge of the situation will lead to insulation damage to the area gradually increased, eventually there may be insulation breakdown of the transformer accident. Finally, once the transformer winding deformation of the situation can easily lead to the cumulative effect of a vicious cycle. Transformer winding deformation does not mean that it will immediately lead to some failures, but with the accumulation of time, what will happen in the future are unpredictable.
2, to prevent the transformer short-circuit solution
①, the transformer in the low-voltage side of the installation of insulated heat shrink sleeve
Transformer in use, the low voltage side of the voltage level is very low, the transformer outlet is generally used in the hard bus, so you can switch from the transformer head to the busbar of the switch cabinet, all installed insulation shrink set. If using a soft bus, can be installed in the transformers and the wall around the casing wall insulation casing around the heat shrink. This can effectively prevent small animals and other short-circuit caused by the transformer. Transformers on the medium and low voltage side of the transformer for the different voltage levels, because it belongs to the neutral point of the small current grounding system, it is necessary to take effective measures to prevent single-phase grounding resonance over-voltage, causing insulation Breakdown, resulting in a short circuit in the transformer.
②, the transformer in the low-voltage side of the pillar vase curing silicone rubber anti-fouling flash paint
Transformer in use, high voltage switchgear can be replaced to climb a larger antifouling porcelain, or brushing at room temperature curing silicone rubber anti-fouling flash coating to prevent insulation breakdown caused by the transformer short circuit. And the room temperature curing silicone anti-fouling flash coating should meet the relevant national standards. You can also transform the low-voltage side of the switch with a greater capacity to switch off the switch to prevent the lack of breaking capacity caused by the switch explosion caused by short-circuit the transformer. Transformer, bus and line lightning arrester should be replaced with all the good performance of zinc oxide surge arresters, improve the equipment over-voltage level. And constantly improve the protection of the transformer configuration. Transformer protection as far as possible to take computerized, dual, as far as possible installation of bus differential protection, failure protection, improve the protection of the reliability, sensitivity and quick action. Transformers in the low-voltage side should be configured to limit the speed of protection, to ensure that the transformer short-circuit, reliable, fast fault removal, short circuit on the transformer to reduce the impact and damage.
3, to prevent short-circuit transformer management measures
First of all, to strengthen the transformer inspection work, in the process of using the transformer, the transformer should be regularly checked, the purpose of doing so is to ensure that the use of the transformer state, when the transformer in use, the transformer can make the examination possible The occurrence of the accident was found in time to reduce the short-circuit transformer damage.