P Sravanthi Int. Journal of Engineering Research and Application www.ijera.com ISSN : 2248-9622, Vol. 6, Issue 6, ( Part -2) June 2016, pp.36-41 www.ijera.com 36 | Page Control of PET Based On Fuzzy Logic for Power Quality Improvement P Sravanthi*, T Srinivasa Rao**, P Anil Kumar*** *(PG Student Scholar, Department Of Electrical & Electronics Engineering, Avanthi Institute Of Engineering & Technology, Narsipatnam, Andhra Pradesh, India, E-Mail ID:sravanthinaidu243@gmail.com) ** (Associate Professor, Department Of Electrical & Electronics Engineering, Avanthi Institute Of Engineering & Technology, Narsipatnam, Andhra Pradesh, India, E-Mail ID:srinivasarao_tegala@yahoo.co.in) *** (Assistant Professor, Department Of Electrical & Electronics Engineering, Avanthi Institute Of Engineering & Technology, Narsipatnam, Andhra Pradesh, India, E-Mail ID:anilkumar.pappala@gmail.com) ABSTRACT During the past several years, fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory, especially in the realm of industrial process, which do not lend of quantities data regarding the input-output relations. This paper presents a power electronic transformer with fuzzy controller. In the design process converters and high frequency transformers have been used. One matrix converter operates as AC/AC converter in power electronic transformer. The proposed AC/AC converter can generate desired output voltage from square input voltage. The main point of proposed PET is reduction of the stage and components of the three-part PETs. The reliability and power quality of distribution system can be significantly improved by using proposed PET. To verify the performance of the proposed PET, computer-aided simulations are carried out using MATLAB/SIMULINK. Keywords: Power electronic transformer (PET), AC/AC Matrix converter, Power Quality, High Frequency Transformer, Space vector Technique, fuzzy control. I. INTRODUCTION Nowadays by the improvement of the semiconductor and power electronics transformers are widely used in electrical power system to perform the primary functions of the transformers. Transformer [1] is most expensive device in an electrical system. A new type of transformers based on Power Electronics (PET) has been introduced, which realizes voltage transformation, galvanic isolation, and power quality improvements in a single device. Different topologies have been presented for realizing the PET, in recent years [2]-[7]. In [2] the AC/AC buck converter has been proposed to transform the voltage level directly and without any isolation transformer. This method would cause the semiconductor devices to carry very high stress. In this a three-part design that utilizes an input stage, an isolation stage, and an output stage [6]-[10]. These types enhance the flexibility and functionality of the electronic transformers owing to the available DC links. This approach can perform different power quality functions and provide galvanic isolation but they need whether too many power electronic converters and DC-link electrolytic capacitors. Thus they result in a rather cumbersome solution. Custom power devices are introduced in the distribution system to deal with various power quality problems faced by industrial and commercial customers due to increase insensitive loads such as computer and adjustable speed drives and use of programmable logic control in the industrial process[11],[12]. In this work two control methods are used, one is PI and another one is Fuzzy logic controller (FLC), The proposed AC/AC converter can generate desired output voltage from square input voltage. The main point of proposed PET is reduction of the stages and components of the three-part PETs. The reliability and power quality of distribution system can be significantly improved by using proposed PET. To verify the performance of the proposed PET, computer-aided simulations are carried out using MATLAB/SIMULINK. II. CONVENTIONAL PET’S Fig. 1 shows the basic block diagram of a PET with DC link capacitor which includes three stages. First stage is an AC/DC converter which is utilized to shape the input current, to correct the input power factor, and to regulate the voltage of primary DC bus. Second stage is an isolation stage which provides the galvanic isolation between the primary and secondary side. In the isolation stage, the DC voltage is converted to a high-frequency square wave voltage, coupled to the secondary of the HF (MF) transformer and is rectified to form the DC link voltage. The output stage is a voltage source inverter which produces the desired AC waveforms [4]-[9]. RESEARCH ARTICLE OPEN ACCESS