الفهرس | Only 14 pages are availabe for public view |
Abstract Nowadays, for technical and economic considerations besides environmental awareness, the application of distributed generators (DGs) such as photovoltaic, wind, hydrogen fuel cells, microturbine, diesel, etc. is increasing. The local interconnection between these distributed generators and load is called microgrid (MG). This microgrid can offer many benefits such as losses reduction during energy transfer from generation unit to load, reduction the amount of harmful gases (greenhouse gases GHG ) by utilization the green energy resources such as wind and photovoltaic and enhancement the system reliability due to dependence on multi-energy resources. Moreover, the islanding operation of these MGs improves the system physical and cyber security. However, in order to enable the microgrid to perform its function, there are some challenges should be faced and overcame. These challenges include maximization the utilization of renewable distributed generator by tracking the maximum power point. In addition, dispatching the power among the different DGs in order to reduce the generation cost and greenhouse gases (GHG) emission. Also, design suitable control mechanism to maintain the system stability in normal and abnormal conditions such as intermittent in the available power from renewable resources or outage one of generation units. Moreover, the microgrid ability to expand by adding new generation units. The Thesis suggests a novel technique to maximize the capture power from Photovoltaic (PV) system by using an artificial neural network (ANN). The proposed technique achieves an excellent tracking factor, eliminates the needing of irradiance devices. Consequently, it is costeffective. Moreover, it does not suffer from the mismatch between iii irradiance measuring devices and actual irradiance strikes the PV array. Eventually, the proposed technique is capable of tracking the MPP irrespective of load nature. The thesis investigates the development of an optimal droop controller to minimize the total generation cost. The suggested controller guarantees the economic operation in case of generation outage, load variation, and PV output variation. In addition to it does not require forecasting of the load and the PV profiles. Moreover, the proposed droop controller considers the effect of the distribution system on power haring accuracy through maximizing the droop gains. Also, the thesis presents an optimal droop controller to minimize the amount of GHG emission. Eventually, in order to enhance the scalability of the microgrid, the thesis suggests robust static state feedback (SSF) local controller based on H2/H∞/pole-placement/polytope. This controller is robust against generation outage, constant power loads, structured uncertainty and unstructured uncertainties. This proposed tuning technique is compared with H2, mixed H2/H∞, H2/H∞/pole-placement techniques and proved its superiority. The proposed control |