The impact of distributed generation on secondary networks

In the 20th century the United States has developed an electric power system (EPS) that became the envy of the world for its reliability and low-cost power.;Today, the US EPS consists primarily of large, central-station plants interconnected via a high-voltage transmission system that delivers power to end-users through lower-voltage, local distribution networks. However, interest in the use of distributed generation (DG) and storage has increased substantially over the past 5 years because of the potential to increase reliability and lower the cost of power through the use of on-site generation.;The advent of competition in the electric power industry, through which customers can shop for the ideal solution for any situation, has been a stimulus for this increased interest. The development of small, modular generation technologies such as photovoltaic, micro turbines, wind turbines, and fuel cells has also contributed to this trend.;DG and storage can have many benefits. However, the technologies and operational concepts needed to properly integrate them into the power system must be further developed to achieve these benefits while avoiding negative effects on system reliability and safety.;In order to have continuous and reliable power for all customers it is necessary to have a good protection system. Major disturbance that are caused and last for a very short duration are called faults. With the advent of DG, the understanding of fault response has become more difficult. This dissertation presents the study of the fault response and the factors that influence the fault response with and without DG. As a part of the fault analysis line to ground faults are placed at various locations in the Sutton Network. Simulation is conducted in EMTP and the results are analyzed. At each node the voltage and the current changes at the time of the fault are recorded. A DG is added to the system and is located at various nodes for each fault and the impact on the fault voltage and current quantities is recorded. A comparison of the impact of faults at various locations is presented. The impact of faults without DG and with DG is also analyzed.