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Showing 2 results for Microgrid
- Rahmani, - Fakharian,
Volume 12, Issue 4 (3-2013)
Abstract
Microgrids are small-scale, low voltage (LV) power networks which employ renewable distribution energy resources (DERs) with power electronic interfaces (PEIs). Microgrids as single controlled units and active distribution networks require flexible control systems to ensure reliable and secure operation in different modes. These various operations of microgrid cause variations in voltage and frequency especially in island mode. In this paper, a new control method with two optimization algorithms (genetic algorithm (GA) & imperialist competitive algorithm (ICA)) are proposed to eliminate both voltage and frequency disturbances. Also, a new concept of conventional droop control in format of fast droop controller (FDC) is designed to guaranty the microgrid system reliability with cooperation of a modern frequency controller. Simulation results show the truth behavior of proposed approach in comparison with previous methods
Mohammad Hasan Hemmatpou, Mohsen Mohammadian, Ali Akbar Gharaveisi,
Volume 14, Issue 1 (5-2014)
Abstract
Microgrids as the "building blocks of smart grids"are predicted to play a major role in the future, as they are capable of improving the technical, environmental and economic fields in large power systems. This paper proposes a new formulation for the islanded Microgrid reconfiguration in order to improve voltage stability index. The formulated problem is solved using harmony search algorithm. The increasing loadability index of microgrids in the islanding mode is more important than the index of the grid-connected mode due to its operational limitations such as reactive power generation. In addition, this paper presented an improved indicator to estimate the voltage stability margin of islanded microgrid system based on the system's operational constraints both saddle node and limited induced bifurcations, called as cat_VSIIMG. The cat_VSIIMG which is validated by verified CPF method for IMGs is called the maximum load ability margin of IMG, . Performance and effectiveness of the proposed method are demonstrated on 33-bus test system. The results show that the implementation of appropriate IMG reconfiguration problem formulations will facilitate a successful integration of the microgrid concept in power systems.
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