Introduction of multi winding transformer

    The so-called multi winding voltage transformer, the transformer has a primary winding, a two winding, such as the common has a basic two windings and a residual voltage winding (also called the zero sequence voltage of the voltage transformer winding). When the system runs normally, the three-phase voltage is symmetrical, and the output voltage of the open triangle is close to zero. At this point, the transformer operates according to the double winding transformer. When the system has single-phase grounding fault, the three-phase voltage is asymmetrical, and the residual voltage winding has zero sequence voltage output. At this time, the transformer operates according to the three winding transformer. Some voltage transformers have two two windings on the two side (one for measurement). The other is for protection) and a residual voltage winding, so the transformer may operate in the four winding state in case of failure.