Paper Title
Study and Simulation of Photovoltaic Distributed Generation System

Abstract
The traditional way in generating of electrical power is to have centralized power plants generating electricity by the means of burning of fossil fuels, which are used as primary energy sources, and feeding loads through a large transmission & distribution network. These loads are increasing day by day due to many different reasons, some of them are: the rapidly growing of the world population, the growing of their living standard and the worldwide industrial revolution with the invention of schools of electric power depending equipment. Without increasing the supply to meet this increase in demand, the electricity economic value will be more expensive and the system will face a lot of problems such as stability problems. It is recommended to increase this supply away from using of conventional fossil fuels, which become more expensive by time and they are going to end one day, and away from polluting the environment around us, as conventional power plants produce high pollution due to burning of fossil fuels resulting in emitting a large amount of gases which are very harmful to all living organisms and to the environment around us. Distributed generation (DG) can be considered as a small-scale power generation technology which provides electric power at a site closer to the customer, and includes technologies such as micro-turbines, fuel cells, and environmental friendly renewable energy technologies such as biomass, solar photovoltaic arrays, small wind turbines and hydro turbines, ranging from sub-kW to multi-MW. DG has the advantage of eliminating the undesired cost of transmission and distribution. In addition, it has a very low effect on account of polluting the environment, reduce maintenance investments, and improve the distribution feeder voltage conditions, increase reliability, and better power quality. Distributed generations (DGs) have gained importance in the last few decades and will continue to gain much more care in the next several years due to the increased life of PV cells, accompanied by an advance in efficiency and lower prices. In the first part of our study, we have analyzed IEEE- 14 bus system under the standard test data & after that we have increased load data in step of 5%. For finding out the most sensitive node, the results are compared with the original power flow results of IEEE- 14 bus system. Voltage stability indices such as line stability index, Fast Voltage Stability Index (FVSI) and Voltage Collapse Prediction Index (VCPI) are some of the most important methods which are used to find out the most sensitive line in the power system. In the second part of our study PV distributed generation is used and the results are compared with the original power flow results. Simulations are carried out using MATLAB SIMULINK TOOLBOX. Keywords - Distributed generation, Photovoltaic, IEEE 14 bus system, Line stability Index (LSI), Line stability factor (LQP), Fast Voltage Stability Index (FVSI), Voltage collapse point index (VCPI), Sensitive node.