Although the introduction of distributed generation (DG) in a distribution system improves the power quality of power system, it increases the fault current level reducing voltage at point of common-coupling (PCC). Hence, there is a need of improving fault ride-through (FRT) capability to avoid sudden tripping of DG units from the utility grid during voltage sag in a faulty condition. In this p...

Microgrid control in isolated mode is a highly important subject area. In the present paper, a new method is used for controlling the isolated microgrids. This method was used based on the classification of the microgrids into two groups, namely fast-dynamic (battery and flywheel) and slow-dynamic (diesel generator, electrolyzer, fuel cell). For the microgrid components with fast dynamics, a se...

Microgrid system has received more and more attention internationally in recent years. As the most effective form of distributed generations, microgrid system has also found wide applications in many areas. In this paper, the optimal configuration issue of microgrid system is described briefly first. And then the monitoring system of microgrid system is discussed in details. Different control m...

A microgrid may operate under two typical modes; the seamless transfer control of the microgrid is very important. The mode conversion controller is installed in microgrid and the control logic of master power is optimized for microgrid mode conversion. In the proposed scheme, master power is very important. The master-power is under the PQ control when microgrid is under grid-connected. And it...

The microgrid (MG) concept is attracting considerable attention as a solution to energy deficiencies, especially in remote areas, but the intermittent nature of renewable sources and varying loads cause many control problems and thereby affect the quality of power within a microgrid operating in standalone mode. This might cause large frequency and voltage deviations in the system due to unpred...

Several control schemes specifically designed to operate inverter-based industrial microgrids during voltage sags have been recently proposed. This paper first classifies these control schemes in three categories and then performs a comparative analysis of them. Representative control schemes of each category are selected, described and used to identify the main features and performance of the ...

Stand-alone direct current (DC) microgrids may belong to different owners and adopt various control strategies. This brings great challenge to its optimal operation due to the difficulty of implementing a unified control. This paper addresses the distributed optimal control of DC microgrids, which intends to break the restriction of diversity to some extent. Firstly, we formulate the optimal po...

By consulting various worldwide definitions of microgrids and distributed energy, this study presents a microgrid-structured multi-agent system and uses Matlab/Simulink to construct a circuit with microgrid features, which enables the changes in each electrical source and load in the microgrid to be monitored and controlled. This multi-agent system adheres to the Java Agent Development Framewor...

After microgrid transition from the normal operation to the islanded operation the system impedance changes considerably and it affects on the harmonic voltages of the microgrid. In this paper the voltage and current THD before and after islanding are studied with different microgrid configurations. Simulations are also made by applying negative sequence filtering in control system of converter...

This paper provides a brief overview of current smartgrid and microgrid technologies and issues associated with their implementation. An architecture of the microgrid for the Department of Electrical Drives and Power Electronics is proposed. Main attention is paid to the control system. The paper sets out the functions and requirements to the main controller for a microgrid control system. The ...