when a distribution network consisting of distributed generations (dgs) is disconnected from upstream network, the system may be exposed to severe power imbalance. in order to prevent the damage of power plants, frequency relays operate and remove dgs from the network. in contrast to traditional methods, the main objective in new methods is to keep dg units in service in the islanded distributi...

The issue of frequency stability of microgrids under islanded operation mode and mode transfer has attracted particular attention recently. In this paper, a cooperative frequency control method, which consists of a microgrid central control (MGCC) and microgrid local control (MGLC), is proposed to achieve a seamless transfer from grid-connected to islanded mode, and hence increase the frequency...

The objective of this paper is to present novel control strategies for MicroGrid operation, especially in islanded mode. The control strategies involve mainly the coordination of secondary load-frequency control by a MicroGrid Central Controller that heads a hierarchical control system able to assure stable and secure operation when the islanding of the MicroGrid occurs and in load-following si...

This paper proposes the grid synchronization method of inverter using a quasi Proportional+Multi Resonant (P+MR) control-based voltage controller a stationary reference frame. The inverter supplies a non-linear load under the islanded mode. In islanded mode, the inverter is defined as a voltage source to supply the full local load demand without a connection to the grid. On the other hand, if t...

Streamingangebote und Live-Übertragungen von Opernaufführungen, allen voran die Serie "Met live: in HD", gehören seit rund einer Dekade zum Kulturangebot generieren ein eigenes Opernpublikum. Sie führen zu einem allmählichen Wandel der Operndramaturgie. Diese übersteigt traditionelle Formen Produktionsdramaturgie, sich eher auf einzelne Inszenierungen bezieht, führt neuen Form institutioneller ...

Wind power development is booming globally, and large scale onshore wind power is under development in China, the Americas and India. Compared with AC transmission, HVDC technology can due to lower losses be attractive if the distance from generation to consumption is long. VSC (Voltage Source Converter) HVDC is rapidly maturing as a technology, and offers some significant advantages compared t...

When a distribution network consisting of Distributed Generations (DGs) is disconnected from upstream network, the system may be exposed to severe power imbalance. In order to prevent the damage of power plants, frequency relays operate and remove DGs from the network. In contrast to traditional methods, the main objective in new methods is to keep DG units in service in the islanded distributi...

An article entitled: `A Note on Modeling Multiple Choice Requirements for Simple Mixed Integer Programming Solversa was published by Ogryczak (Comput. Oper. Res. 23 (1996) 199). In this article, Ogryczak proposed a reformulation technique called special ordered inequalities (SOI) to model the non-convex programming problems with special ordered sets (SOS) of variables. The SOI technique appears...

As usual, the microgrid operates in grid-connect mode, but, when a fault occurs in the upstream grid, it should disconnect and shift into islanded operation mode. In grid-connect mode, the controlling power at the PCC is necessary management function rather than the frequency and voltage. However, the controlling the frequency and voltage is asked in islanded mode. To achieve these management g...