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Electrical knowledge

Transformer protection device measures

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Update time : 2018-01-25 14:36:14
First of all,transformer failure, we often mentioned a problem, the general breakdown of the transformer is divided into internal faults and external faults.
1. Internal fault
The main faults in the transformer include winding phase short circuit, winding turn short circuit and neutral grounding system winding ground short circuit. These faults are very harmful because the high temperature arc generated by the short-circuit current will not only burn the core of the winding insulation box, but also decompose the insulating material and the transformer oil to generate a large amount of gas, which may cause the transformer tank to partially deform, crack or even explode ACCIDENT. Therefore, when an internal transformer failure, the transformer must be quickly removed.
2. External fault
Transformer external fault is mainly the transformer casing and pin-out of the phase short-circuit and ground short. In the event of such failures, the transformers should also be quickly removed to minimize the impact of short-circuit currents on the transformers.
Second, the transformer is not working properly
Transformer abnormal working conditions mainly realized as:
(1) Current caused by external short circuit.
(2) overload.
(3) oil tank oil spill caused by reduced.
(4) Transformer neutral point voltage rise or external voltage is too high or frequency caused by over-excitation.
Third, the transformer should be installed protection device
(1) Gas protection that reflects internal faults in the transformer tank and reduced oil level.
(2) to reflect the transformer windings and leads the phase short-circuit, the neutral point of the direct grounding system winding and pin-out single-phase short circuit protection or current instantaneous short circuit protection.
(3) It reflects over-current protection (or over-current protection or negative-sequence overcurrent protection for compound voltage starting) that is reserved for the protection box differential protection (or current quick-break protection) of transformer.
(4) Zero-sequence current protection that reflects the external short-circuit of the transformer and the internal short-circuit in the neutral grounding system.
(5) reflect the symmetrical transformer overload overload protection.
(6) reflect the transformer over excitation protection.
These are some of the transformer failures and protective measures.