Three-phase distribution transformer connections modeling based on matrix operation method by phase-coordinates

Zhigang Zhang,Caizhu Wu,Mingrui Mo

doi:10.1186/s13638-021-01945-z

Abstract

This paper proposes a matrix operation method for modeling the three-phase transformer by phase-coordinates. Based on decoupling theory, the 12 × 12 dimension primitive admittance matrix is obtained at first employing the coupling configuration of the windings. Under the condition of asymmetric magnetic circuits, according to the boundary conditions for transformer connections, the transformers in different connections enable to be modeling by the matrix operation method from the primitive admittance matrix. Another purpose of this paper is to explain the differences of the phase-coordinates and the positive sequence parameters in the impedances of the transformers. The numerical testing results in IEEE-4 system show that the proposed method is valid and efficient.

Highlights

The purpose of this paper is to model the three-phase transformers in different connections by phasecoordinates by matrix operation method
2 Methods/experimental The aim of this paper is to solve the problem for winding connections modeling of three-phase transformer by phase-coordinates based on matrix operation method
3 Modeling methodology the modeling approach for a transformer is described by the matrix operation method from the 12 × 12 dimension primitive admittance matrix

Summary

Introduction

With the rapid development of the distributed generators and the wide use of electric vehicles, the unbalanced condition of distribution systems are getting worse by those single-phase power supply and loads increasingly [1, 2]. In this case, it is great need to promote the research and analysis of the unbalanced distribution systems. In modern distribution system analysis, models of the transformers play an important role in power-flow analysis and short-circuit studies. It is necessary to study a new approach modeling three-phase transformer connections by phase-coordinates in unified matrix analysis

Objectives

Methods

Results

Conclusion