In the operation of the transformer, resulting in asymmetric operation, the main reason there are three aspects:
(1) As the three-phase load is not the same, resulting in asymmetric operation. For example, the transformer with high-power single-phase electric furnace, electric locomotives and welding transformers.
(2) by the three single-phase transformer composed of three-phase transformer group, when a damage with a different parameter to replace the transformer, resulting in current and voltage asymmetry.
(3) due to some reason to make the transformer two-phase operation, caused by asymmetric operation. For example, in a neutral-grounded system, when a phase line is faulty and a zero line is used instead of the phase transient operation, a transformer fault in the three-phase transformer group is running with a two-phase transformer, three-phase transformer one-phase winding fault. One side of the transformer side of the circuit breaker is disconnected, the transformer tap the bad contact.
      Transformer asymmetrical operation of the consequences are: the capacity of the transformer to be reduced, you can use the capacity is still smaller than the two-phase transformer is still running the sum of the rated capacity. And the size of available capacity and the degree of asymmetry of the current. Asymmetric operation of the transformer, not only the transformer itself has some hazards, but also because of current and voltage asymmetric operation of the user's work is affected, while the interference along the communication lines, power system protection of working conditions And so can not be ignored.