ارزيابي عملكرد و پياده سازي اينورترهاي تكفاز متصل به شبكه با كنترل كننده هاي ميتني بر مختصات سنكرون و ثابت

چكيده انگليسي :

Performance Evaluation and Implementation of Single Phase Grid Connected Inverters Based on Synchronous and Stationary Reference Frame Controllers Mohammad Ebrahimi mo ebrahimi@ec iut ac ir Date of submission January 22 2013 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr Hamidreza Karshenas karshen@cc iut ac ir Abstract This thesis is concerned with the dynamic and steady state performance evaluation of single phase grid connected inverters using different control methods Renewable Energy Systems RES have been widely used as a viable approach to obtain sustainable energy resources due to the increasing price of fossil fuels environmental concerns and growing demand for energy consumption The energy produced by renewable energy sources is usually raw and mostly in dc form For example photovoltaic PV cells produce dc energy with large fluctuation depending on the Sun insolation As almost the entire electric energy consumption is in the ac form an inverter is an indispensable part of the grid connected renewable energy systems to interface between the source and load Many governments have set up incentives for residential use of renewable energy resources The power level and accessible type of grid in such applications is usually single phase The above factors have resulted in a considerable growth of single phase grid connected inverters in recent years Therefore optimum and efficient operation of single phase grid connected inverters have become an important issue for researchers In this thesis different methods of extracting the phase and frequency of the grid voltage in a single phase system using a Phase Locked Loop PLL have been introduced Using Park Transformation for implementing a single phase PLL has been shown Different methods of orthogonal quantity generation as a key block for realizing this type of PLL are presented The performance of different methods have been compared using both simulation and experimentally Current mode control is often used to control a grid connected inverter Therefore several approaches have been introduced for controlling single phase grid connected inverters based on current mode control Control methods using Proportional Integral PI controllers in synchronous reference frame and Proportional Resonance PR controllers in stationary reference frame are considered in this thesis because of their satisfactory performance and popularity The existence of two coupled orthogonal quantities in a three phase system makes it possible to use Park Transformation in order to transfer the quantities from stationary to synchronous reference frame However single phase systems lack such a pair of orthogonal quantities Therefore the implementation of a controller in synchronous reference frame cannot be performed by itself for single phase systems To overcome this problem and exploit the advantages of control in synchronous reference frame the second required orthogonal quantity is usually synthesized by various methods for implementation of the controller in synchronous reference frame In this thesis a comprehensive study is presented to evaluate and compare the performance of these methods To study the dynamic performance the model of the system is obtained with all system blocks taken into consideration Using this model the dynamic behavior of controllers implemented with different orthogonal signal generation techniques is evaluated The results are also compared with a PR controller An experimental setup was implemented using a TMS320F28335 DSP to experimentally verify the theoretical results Key Words Single Phase Inverter Grid Connected Inverter Current Control Synchronous Reference Frame Orthogonal Quantity Generation Proportional Resonant Controller

ابراهيمي، محمد

ارزيابي عملكرد و پياده سازي اينورترهاي تكفاز متصل به شبكه با كنترل كننده هاي ميتني بر مختصات سنكرون و ثابت

كنترل جريان , قاب مرجع سنكرون , توليد كميت متعامد , كنترل كننده تناسبي , رزونانسي