Virginie Majchrzak, Guillaume Parent, Jean-François Brudny, Valentin Costan and Philippe Guuinic
For the proposed coupling transformer, a magnetic bypass based on the virtual air gap principle is realized by inserting auxiliary windings in a return leg added to a standard…
Abstract
Purpose
For the proposed coupling transformer, a magnetic bypass based on the virtual air gap principle is realized by inserting auxiliary windings in a return leg added to a standard transformer. With such a setup, it is able to act as a voltage regulator as well as protect the power electronics of the dynamic voltage restorer from electrical grid fault currents. This paper focuses on the electrical design part of the coupling transformer. It aims to explain how the behavior of the auxiliary windings electrical circuit of the magnetic bypass impacts the performances of the device.
Design/methodology/approach
The influence of the electrical auxiliary windings circuit configurations on the operation of the coupling transformer is studied by finite element analyses with nonlinear and isotropic magnetic materials.
Findings
A configuration for the realization of the electrical circuit of the auxiliary windings is determined according to the finite element simulation results to achieve the design of the coupling transformer whose magnetic core was previously designed.
Originality/value
By studying the operation of a special coupling transformer with nonlinear saturation phenomenon by finite element analyses, a to-do list of the electrical circuit parameters is described to design this device well.
Details
Keywords
Jean‐Paul Swan, Olivier Walti and Jean‐Fraçois Brudny
Electrical machines are more and more fed by static converters. These power supplies impose nonsinusoidal statoric waveform to the machines. In these conditions, behaviour of…
Abstract
Electrical machines are more and more fed by static converters. These power supplies impose nonsinusoidal statoric waveform to the machines. In these conditions, behaviour of magnetic material can be very different compared with sinusoidal ones. The characterization of magnetic material under non‐sinusoidal excitations is not clearly defined. At the present time, there is not any standard about operating test and specific parameters to be measured in order to get efficient knowledge of soft magnetic materials in distorted excitation mode. The aim of this paper is to present the effect of statoric connections on harmonic characterization parameters. The experimental results correspond to a Fe‐Si non oriented material excited by two different waveforms in a classical Epstein frame. The behaviour of the material is divided into two parts: the fundamental and the harmonic responses. The fundamental parameters are representative of the duty frequency of the machine, harmonic ones give information about additional losses; especially their harmonic distribution. They also allow us to estimate harmonic impact on the fundamental response.