Distributed Generation (DG) technique has achieved prodigious progress recently. The distributed generator, normally defined as a small generating unit (<10 MW) installed in the distributed system, is expected to play an increasing role in the emerging power system and thus improve the reliability of the system and load point indices. Normally, distributed generators are installed near the customer side so as to have a great impact on the power system, especially on the distributed system. Reduction of system expansion costs, decreasing loss of power and reliability enhancement are some of the benefits of DG application. In this paper, an appropriate model is developed to assess the impact of DG on reliability indices. An analytical probability approach is developed for this study. Reliability indices of distribution system are evaluated without DG, with DG, and swapping two DGs using the model developed. The indices thus obtained are compared. The analysis demonstrates that the DG has the ability of improving the reliability of system. It provides some useful conclusions such as the impact of the site of the DG on the reliability of the distribution system. It can be observed from a comparison of the results that when system obtains the large capacity DG is installed, the higher reliability level.

Reliability modeling and evaluation of distribution systems has not received much attention in the literature compared to the generating systems. The main reasons for this are: generating stations are individually very capital-intensive, and generation inadequacy can have widespread catastrophic consequences for both the society and its environment. A distribution system, however, is relatively cheap and outages have a much localized effect (Billinton and Allan, 1996). Therefore, less effort has been devoted to quantitative assessment of the adequacy of various alternative designs and reinforcements. On the other hand, an analysis of the customer failure statistics of most utilities shows that the distribution system makes the greatest individual contribution to the unavailability of supply to a customer. Chronological statistics reinforce the need for the reliability evaluation of distribution systems to evaluate quantitatively the merits of various reinforcement schemes available to the planner and to ensure that the limited capital resources are used to achieve the greatest possible incremental reliability and improvement in the system (Purushotham et al., 2007).

Distribution system is an important part of power systems. Most of the customer interruptions in power systems are caused by contingencies in distribution systems. It is reported that about 80% of outages are due to faults in the distribution systems. As customer demand, lower expenses and higher reliability increase, distribution system reliability evaluation has become one of the most important issues in power system analysis. Distribution generation (DG) refers to the power generation by the small generating units connected to the distribution systems. DG is expected to play an increasing role in the emerging electric power systems (Ackerman et al., 2001).

Reduction of the system costs, decreasing loss of power and reliability enhancement are some of the benefits of the DG application. DG can improve the utility's ability to serve peak load on a feeder and help to supply load during contingencies (El-Khattam and Salama, 2004).

Electrical and Electronics Engineering Journal, Biometric Fingerprint Segmentation, Kernel Fuzzy C-Means Algorithm, Image Segmentation, Data Mining, Gaussian Kernel Function, Reinitialization Process, Medical Images, Medical Imaging Characteristics, Electric Power Systems, Distribution Systems, Reliability Modeling.