electronic copies of this thesis document in whole and in part in any medium now known or hereafter created. ABSTRACT Over the last decade, penetration of microgrids containing distributed generation (DG) sources has increased in grid distribution systems. This requires the stable operation of microgrids when connected to the distribution system as well as during islanding. Islanding that is fa...

Existing control techniques for DG systems are designed to operate a system either in the connected or disconnected (islanding) mode to the utility; thus not allowing for both modes to be implemented and transitioned between. Existing detection and re-closure algorithms can also be improved upon. Dependent upon the method implemented, detection algorithms can either cause distortions in the out...

Island operation of a microgrid increases operation survivability and reliability when there is a large accident in a main grid. However, because a microgrid typically has limited generation capability, a microgrid operator (MGO) has to take the risk of island operation into account in its market participation and generation scheduling to ensure efficient operation. In this paper, a microgrid i...

Due to safety concerns and the risks associated with an islanded system, current legislation has prohibited the islanded operation of distributed generation. However, operation of a temporary island may be a useful support to the main supply. In particular, in the event of an upstream supply outage, the temporary islanding operation of distributed generator (DG) can provide local supplies to cr...

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...

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...

This paper presents a model for microgrid optimal scheduling considering multi-period islanding constraints. The objective of the problem is to minimize the microgrid total operation cost which comprises the generation cost of local resources and cost of energy purchase from the main grid. The microgrid optimal scheduling problem is decomposed into a gridconnected operation master problem and a...

In this paper negative sequence components are used for islanding detection in distributed generation (DG) based system. In this approach, the negative sequence component of the voltage and current signals are analyzed through wavelet transform. The detailed coefficient d1 clearly identifies the event and thus detects the islanding condition. The change in energy and standard deviations of wave...

this paper develops a model for distribution network expansion planning (dnep) considering reliability issues. with simultaneous switch placement and dnep, the proposed model tries to adequately consider the reliability issues in the planning stage in a way that the designed network has suitable performance from the reliability viewpoint. the reinforcement or installation of mv feeders and hv/m...