Transformer three-phase imbalance which harm
1, when the line is not full-phase operation, the zero sequence current is equivalent to the load current, then the line with its adjacent line zero sequence current may be large, even greater than the zero sequence backup protection settings, if not quickly cut Non-full-phase operation of the line, it may lead to adjacent line malfunction, leap-off;
2, for 220kV and above generator transformer group and machine-side circuit breaker, due to non-full phase operation during a larger negative sequence current, the generator, the transformer may cause a greater damage to the equipment.
There is no obvious harm to the transformer, but will limit the capacity of the transformer can not get 100% play. For example, A-phase current close to the transformer rated current, B, C-phase current only 10% of the rated current, but then the transformer can no longer take any three-phase power equipment, limiting the capacity of the transformer.
