A micro grid (MG) is a local energy system consisting of a number of energy sources (e.g., wind turbine or solar panels among others), energy storage units, and loads that operate connected to the main electrical grid or autonomously. MGs provide flexibility, reduce the main electricity grid dependence, and contribute to changing large centralized production paradigm to local and distributed ge...

The objective is to minimize the fuel cost during the grid-connected operation, while ensuring stable operation after islanding. To achieve this goal, the economic dispatch (ED) problem and related constraints are formulated. The constraints considered in this study are: i) reserve for variation in load demand, ii) reserve for variation in the power outputs of non-dispatch able DGs, iii) flow l...

Abstract This study proposes a novel combined primary and secondary control approach for direct current microgrids, specifically in islanded mode. In control, this establishes an appropriate load power sharing between the distributed energy resources based on their rated power. Simultaneously, it considers voltage deviation provides satisfactory regulation loop. The proposed is efficient droop ...

Microgrids work in two modes, grid connected and islanded. Short circuit levels in islanded mode tend to be small compared to those in grid-connected mode. Moreover, power flows in microgrids are not always unidirectional. For these reasons, it is difficult to protect microgrids using relaying strategies traditionally used in distribution systems. In this paper, a new technique is presented whi...

The μCHP is expected as the successor of the conventional high-efficiency boiler producing next to heat also electricity with a comparable overall efficiency. A μCHP appliance saves money and reduces greenhouse

A low voltage distribution network with large amounts of small sized dispersed generation can be operated as an isolated system in certain conditions. This paper presents the control strategies to be used in such a system to deal with islanded operation and to exploit the local generation resources as a way to help in power system restoration after a general blackout. A sequence of actions for ...

Received Sep 4, 2017 Revised Oct 21, 2017 Accepted Nov 18, 2017 This paper presents an investigation about the impact of integrating renewable energy based generation sources on the existing distribution system in terms of load sharing. The study of load sharing among various distributed generators (DGs) and utility grid has been performed for two cases: (a) when equivalent source based DG is c...

A microgrid is composed of distributed power generation systems (DGs), distributed energy storage devices (DSs), and loads. To maintain a specific frequency in the island mode as an important requirement, the control of DGs output and charge action of DGs are used in supply surplus conditions and load-shedding and discharge action of DGs are used in supply shortage conditions. Recently, multiag...

In order to integrate a proton exchange membrane type (PEM) fuel cell system (FCS) combined with a battery bank to a distribution grid; this paper proposes a local controller based on fuzzy logic. The proposed system provides primary frequency control and local bus voltage support to the local grid. This opposes the passive distributed generation of the present that do not provide auxiliary ser...