Determination of Allowable Capacity of Distributed Generation with Protection Coordination Consideration

Abstract

The presence of distributed generation (DG) provides considerable benefits from both engineering and economic viewpoints. However, it changes radial configuration of the distribution feeders. Consequently it may cause coordination failure to existing protection system which is originally set based on radial configuration. In addition, high penetration level of DG may increase feeder loss, and cause system voltage profile out of a required range. This paper presents an optimization based method to calculate maximum allowable capacity of a DG considering a set of constraints formulated to maintain protection system coordination. In addition feeder loss and system voltage constraints are also taken into account. With the developed methodology, the maximum DG capacity which does not provide adverse effects to the existing system, i.e. violate protection coordination, increase feeder loss, and cause voltage violation, can be obtained.

Progress on Protection Strategies to Mitigate the Impact of Renewable Distributed Generation on Distribution Systems

“…In [46,47], a strategy which focuses only on the optimum size of DG was presented. Mirsaeidi et al in [47] calculate the DG maximum size at each bus in order to prevent protection miscoordination in DNs.…”

“…Similarly, the authors in [46] also determined the DG optimum size based on an optimization method by allowing for a set of constraints, formulated to keep the protection coordination in the DN. Power losses and system voltage limitations are also being considered to avoid adverse effects to the existing system.…”

Load variation impact on allowable output power of distributed generator with loss consideration

“…The problem is to determine maximum allowable DG output power for a specific location that will not increase the total system loss. This problem can be considered as an optimization problem subjected to an appropriate set of constraints [5].…”

“…Based on that, the maximum allowable DG output power for the specified location can be searched directly. More detailed information can be found in [5].…”

“…system capacity deferral, voltage regulation, and loss reduction [1,2]. The location and output power of a DG can be appropriately determined in such a way that the system loss is minimized [3][4][5]. However, the determination of these parameters is generally done at a certain system operating point.…”