The operation of Fuel Cell Distributed Generation (FCDG) Systems in distribution Systems is introduced by modeling, controller design, and simulation study of a Solid Oxide Fuel Cell (SaFe) Distributed Generation (DG) system. The physical model of the fuel cell stack and dynamic models of power conditioning units are described. Then, suitable control architecture based on fuzzy logic control for the overall system is presented in order to active power control and power quality improvement. A MATLAB/Simulink simulation model is developed for the SOFC DG system by combining the individual component models and the controllers designed for the power conditioning units.Simulation results are given to show the overall system performance including active power control and voltage regulation capability of the distribution system. 

In addition to the great benefits of Distributed Generation (DG) resources to power Systems, there are some disadvantages. In spite of some benefits like decrease of received power from transmission grid, increment of DGs penetration can lead to voltage increase in distribution networks during off peak. Hence the recent efforts have been made to handle problems to increase the penetration of these resources. The use of energy storage Systems (ESSs) is one of the ways to prevent defects may arise from use of DGs in power Systems and can help to increase penetration of DGs in power Systems. ESSs can save energy during off peak and deliver it to the network in peak hours; hence, these equipment can reduce power losses and prevent voltage deviation during off peak by increasing load due to ESS charging.In this paper, first DG allocation and ESS placement are introduced then simultaneous placement of DG and ESS to reduce power losses in the distribution network are described. The proposed models are solved using genetic algorithm as optimization tool. The obtained results show that simultaneous placement could increase DG penetration compared to the separate allocation of these devices and provide further reduce of the losses in the distribution network.

As the proportion of total Generation by renewable sources compared to non-renewable sources increases, the relative inertial stability provided by large rotating generators in electricity grids is found to shrink and is not being replaced by sources such as photovoltaic and wind power, which are already known for their inherent variability. This leads to electricity Generation Systems being less stable, less flexible, and less adequate in applications with a high diversity factor, and literature shows that the penetration of renewable energy sources in distribution-Generation/microgrid system frequently presents several technical and economic challenges in their usual applications. This work examines how increased renewable energy penetration impacts the distribution-Generation system and suggests approaches and measures for tackling the challenges that are associated with it.

In this paper, a method for improving the performance of the network protection system in the presence of DGs by use of intelligent devices is proposed. The method, which is implemented on a hierarchical multi-agent structure, can improve the coordination problems between overcurrent relays by using a telecommunications platform based on the IEC-61850 standard information model. By this way, the protection scheme is implemented on three levels on the relays. Each level has tasks that are implemented on a layered multi-agent structure, depending on the layout of the network under certain conditions. At the first protection level performed by relay agents, the relay protection characteristic curve is used along with the functions defined on the intelligent devices. At the second level, a database is used to record the events and the pattern of behavior chosen according to them in order to prevent the flow of information on the network and to speed up the performance of the protection system. Functional patterns recorded in the database allow agents to obtain appropriate settings without sending information to the central unit if similar conditions occur. At the third protection level, in the absence of a similar pattern, the new relay settings are calculated according to the network conditions and transmitted to the network monitoring unit. Finally, in order to verify and validate the proposed method, the proposed scheme is simulated on an experimental network in the ETAP software.

The recent trends in electrical power distribution system operation and management are aimed at improving system conditions in order to render good service to the customer. The reforms in distribution sector have given major scope for employment of Distributed Generation (DG) resources which will boost the system performance. This paper proposes a heuristic technique for allocation of distribution Generation source in a distribution system. The allocation is determined based on overall improvement in network performance parameters like reduction in system losses, improvement in voltage stability, improvement in voltage profile. The proposed Network Performance Enhancement Index (NPEI) along with the heuristic rules facilitate determination of feasible location and corresponding capacity of DG source. The developed approach is tested with different test Systems to ascertain its effectiveness.