چكيده به لاتين
Microgrids are small power devices that integrate several elements such as controllable and non-controllable loads, DG units and energy storage elements using power electronic devices. Microgrids, which are small-scale smart grids, are considered as one of the most interesting solutions for improving power dispatching in distribution networks and loss reduction in transmission lines using Distributed Generation, Energy Storage Systems (ESS) and loads in grid. Microgrids have the ability to integrate various energy sources which leads to higher efficiency and more compatible energy resources to environment comparing to conventional power devices. For consumer, microgrids can respond to specific local demands in terms of thermal-electrical needs and also improve power quality in terms of voltage regulation and local frequencies.
In this thesis, first we introduce microgrid systems, distributed generation, and their different types such as AC microgrids, DC microgrids and hybrid AC/DC microgrids. Then, a brief discussion of the hybrid type advantages is presented. Also, we investigate two new structures in power systems. Delta source impedance grids and circuit analysis along with performance evaluation are presented. After that, developed multilevel converters, their operational procedure and their topologies are discussed. Then, each element of hybrid microgrid system is introduced separately along with their control and operational procedures. Finally, different models such as photovoltaic systems, wind turbine with permanent magnet synchronous generator, battery system and grid-connected inverter system.
In this thesis, a hybrid AC/DC microgrid with new structure, photovoltaic cell components, wind turbine and a battery capacitor are modeled and connected to the grid using proper converter. The connection of these components within a microgrid requires a precise control system which is designed in this work. Final hybrid microgrid model is simulated in MATLAB using Simulink. The simulation results show a promising performance for this microgrid under different load and grid conditions.
Simulation results for hybrid microgrid model and the performance of each grid components are presented in different operational conditions which verify the performance of the entire model and its components.
Finally, the conclusion for this hybrid AC/DC microgrid model is presented and some future approaches are introduced.
