Performance analysis of electronic power transformer based on neuro-fuzzy controller

Abstract

In recent years, electronic power transformer (EPT), which is also called solid state transformer, has attracted great interest and has been used in place of the conventional power transformers. These transformers have many important functions as high unity power factor, low harmonic distortion, constant DC bus voltage, regulated output voltage and compensation capability. In this study, proposed EPT structure contains a three-phase pulse width modulation rectifier that converts 800 Vrms AC to 2000 V DC bus at input stage, a dual active bridge converter that provides 400 V DC bus with 5:1 high frequency transformer at isolation stage and a three-phase two level inverter that is used to obtain AC output at output stage. In order to enhance dynamic performance of EPT structure, neuro fuzzy controllers which have durable and nonlinear nature are used in input and isolation stages instead of PI controllers. The main aim of EPT structure with the proposed controller is to improve the stability of power system and to provide faster response against disturbances. Moreover, a number of simulation results are carried out to verify EPT structure designed in MATLAB/Simulink environment and to analyze compensation ability for voltage harmonics, voltage flicker and voltage sag/swell conditions.

Adaptive Control of Solid State Transformer Using Type-2 Fuzzy Neural System

“…Moreover, the rapid reduction of fossil fuel resources requires the search for alternative sources of energy to find a solution for future energy production. With the developing technology, the rising living standards and the increasing population, the requirement of electric energy is increasing day by day [1,3]. It is well-known that electricity is provided to consumers by passive transformers, transmission lines, and substations.…”

“…New technological solutions are required to eliminate these problems. In addition, efforts to develop transformers with technological advances have been increasing rapidly in recent years [1,4,6,10]. New type transformers, which are considered as one of these technological developments, are called as solid state transformer (SST), intelligent universal transformer (IUT) or electronic power transformer (EPT) [11].…”

“…Although SSTs were first proposed by Mc Murray in 1970, the studies on these transformers has shown intense interest during the last 20 years [11]. The aim of all studies is to design a transformer which can carry out all the properties of classical transformers in a single circuit and consisting of completely semiconductor elements [1,5]. Moreover, the most important purposes of these studies are to obtain the following characteristics from the transformer structure: power factor correction, voltage sag/swell compensation, fault isolation, fixed output voltage.…”

“…Moreover, the most important purposes of these studies are to obtain the following characteristics from the transformer structure: power factor correction, voltage sag/swell compensation, fault isolation, fixed output voltage. In order to achieve these purposes, scientists and academics have made many studies and published articles on the design and control of SSTs [1,4,5]. The selection of the appropriate topology is an important issue for SST implementation.…”

Power electronic transformer with adaptive PLL technique for voltage-disturbance ride through

“…It is found that the SPC is suitable for dealing with a full range of unbalanced loads under the condition where the input-stage current stress increases. Nonlinear and intelligent controllers such as an internal model controller, a sliding mode controller, and a neurofuzzy controller are adopted in [18][19][20] to improve PET performance.…”