This paper presents a thorough control structure of the distributed generators inside microgrid during both grid-connected and islanded operation modes. These structures DGs voltage source inverters are implemented in synchronous reference frame (SRF) controlled using linear PI controllers. By implementing structures, desired real reactive power can be efficiently transferred to local loads uti...

The electric power sector due to the great expansion of distributed generation has been undergoing many transformations. Within this context a new concept is being widely discussed: microgrid. A microgrid formed by set electrical loads, sources and energy storage elements, can operate in grid-connected islanded mode. However, mode low short-circuit power, presence generators electronic converte...

The growth of penetration of Distributed Generators (DGs) is increasing the risk of unwanted islanded operation in Low Voltage (LV) distribution systems. In this scenario, the existing anti-islanding protection systems, installed at the DG premises and based on classical voltage and frequency relays, are no longer effective, especially in the cases of islands characterized by a close match betw...

Since microgrids should be able to smoothly operate in two distinct modes—grid-connected and islanded, their fault currents can widely fluctuate depending on the operational mode. When microgrid is connected grid, highest current, by far, supplied utility grid. In this mode, current contribution from distributed energy resources (DERs) less than 20%. However, when switches islanded grid lost DE...

This paper contains a control scheme for power sharing in islanded microgrids with invertersourced distributed energy resources that combines robust control and droop control. As the load within the microgrid changes, the inverter-sourced generators share the change in the load; this paper shows that the uncontrolled load sharing among the generators will be arbitrary and methods such as droop ...

Microgrids are eco-friendly power systems because they use renewable sources such as solar and wind power as the main power source. However, the stochastic nature of wind and solar power is a considerable challenge for the efficient operation of microgrids. Microgrid operations have to satisfy quality requirements in terms of the frequency and voltage. To overcome these problems, energy storage...

The increasing penetration of dispersed generation (DG) brings challenges to conventional protection approaches of distribution system, mainly due to bi-directional power flow and variable fault current contribution from different generation technology-based DG units. Moreover, the trend of allowing islanded operation of distribution systems necessitates the adoption of adaptive protection meth...

Frequency stability of microgrids under islanded operation attracts particular attention recently. A new cooperative frequency control strategy based on centralized multi-agent system (CMAS) is proposed in this study. Based on this strategy, agents sent data and furthermore each component has its own to center operating decisions (MGCC).After deciding on the information, they are returned. Freq...