in this paper, we investigated the necessity and effects of optimal control methods in the stability and performance of a micro-grid that operates in islanded mode. the micro-gird is consisted of a combine heat and power (chp), a capacitor bank (cb), photovoltaic panel (pv) as power generation sources. in addition, battery and the building electricity and thermal load are placed on the load sid...

Islanding is a condition where a part of the distribution system becomes electrically isolated from the remainder of the power system. The islanding detection for distributed generation (DG) units becomes an important issue in power system where the DG installations must be managed and protected during the islanded mode of operation. This paper proposed a new signal processing technique by intr...

In islanding, a portion of the power network, comprised of the loads and distributed generation (DG) units, is isolated from the rest of the power grid and forms a micro grid (MG). In this condition, it becomes essential for the islanded MG to operate in a stable and controlled manner by providing ancillary services. When the MG is cut off from the main grid, the islanding must be detected by t...

This paper presents a microgrid stability controller (MSC) in order to provide existing distributed generation units (DGs) the additional functionality of working in islanding mode without changing their control strategies in grid-connected mode and to enhance the stability of the microgrid. Microgrid operating characteristics and mathematical models of the MSC indicate that the system is inher...

Considering the advantages of DC microgrids, the extension of the conventional AC distribution grid can be implemented using a DC microgrid. This justifies the realization of a hybrid AC/DC microgrid. In the present study, a new global solution is presented to improve the power quality and to fully compensate the reactive power of an AC microgrid using DC bus capacity while introducing a new de...

In recent years, most of the loads and distributed generations are connected to the AC grid through the power electronic converters. Using the DC grid beside the AC grid can reduce the conversion stages and power losses. Protection of the DC grids is a challenging issue because of the new structures of DC grids and fast transients of the DC faults. This paper studies the protection of the low v...

The microturbine generation (MTG) system are becoming the popular source of distributed generation (DG) due to their fuel flexibility, reliability and power quality. The MTG system is a complicated thermodynamic electromechanical system with high speed of rotation, frequency conversion and its control strategy. In spite of several techniques to control high speed of microturbine is not accurate...

The microgrids are composed of small scale fueled generation capacities, renewable energy sources, storage energy systems, controllable loads, and autonomously can connect or disconnect from the mains supply. The microgrids can operate connected to the upstream main grid, or in an islanded operation mode following a large perturbation in the upstream grid. The microgrid analyzed in this paper i...