Design of fractional-order control systems for three-phase voltage source DC/AC inverter

Three phase voltage sourced DC/AC inverters are a power electronic device that converts DC power from a battery into conventional AC power. The AC power produced at the DC/AC output can be of any amplitude and frequency depending on the used transformers, switching and control circuits. It is possible to obtain AC voltage at the desired amplitude and frequency from the three-phase DC/AC inverter by precisely determining the control parameters of the inverter. Various control methods have been proposed for the control of DC/AC inverters. PI and PID controllers are widely used in controlling DC/AC inverters because their control structures are simple and useful. Recently, due to the development of computer technology and many advantages of fraction control structures, fractional-order PI and PID controllers have replaced traditional PI and PID controllers. Research and studies in academia and industry have shown that fractional-order control structures are more successful in controlling DC/AC inverter systems than classic control structures. In this thesis study, fractional-order PI and PID controllers are designed for voltage control in the three-phase voltage source DC/AC inverter system. For this purpose, mathematical modeling of DC/AC inverter system was studied and transfer function of the inverter system was obtained. Firstly, a three-phase voltage sourced DC/AC inverter was controlled individually with traditional and fractional-order PI/PID approaches to improve the quality of the voltage in a residential building, where wind and solar energy systems are integrated. In addition, FOPI-PD/PI-PD and FOPI-I/PI-I controllers were designed for the BIPv/Wt system and the advantages of these control structures in determining the quality of electrical power used in homes were investigated. In the next study, the performance of DC/AC inverters with fractional-order and traditional PI/PID controllers was investigated under resistive, capacitive and inductive load. The results obtained from the studies show the success of fractional order control structures. Keywords: Three-phase voltage sourced DC/AC inverters, control systems, fractional-order controller design, building integrated wind turbine and solar panels.