Method of ParametersDeterminationfor Multi-WindingTransformer Equivalent Circuitin the Form of Multi-BeamStar

Abstract

For the case of transformer with a number of windings four or more, the number of pair short-circuit impedances are morethan the number of beams of the corresponding star, which makes it impossible to obtain a sufficiently correct equivalent scheme in the form of a multi-beam star without electromagnetic coupling between the elements of the beams. The scope of this paperis the elaboration of the technique for determining the elements of the equivalent circuit for the replacement of a multi-winding transformer in the form of multi-beam star with mutual electromagnetic coupling between the elements of the beams, with one magnetization branch. The scope of the article is achieved by application of the formula that connects the pair short-circuit impedance of the two windings with their total own and mutual impedance. Using the matrix pseudo-inversion procedure, a technique was developed for finding the own and mutual impedances, constituting the star's beams. The new results consist in the fact that this equivalent scheme is universal and did not depend on the specific mutual arrangement of the windings. Besides, it is possible to determine the parameters of the proposed multi-beam equivalent circuit in exact accordance with the values of the pair short-circuits impedances of the transformer and is a logical continuation of the conventional equivalent scheme of three-winding transformer. In addition, the proposed algorithm ensures the positive values of the own inductive resistances of the beams (windings).

Keywords

• equivalent scheme
• a
• multi-beam star