The aim of the relay coordination is that protection systems detect and isolate the faulted part as fast and selective as possible. On the other hand, in order to reduce the fault clearing time, distance protection relays are usually equipped with pilot protection schemes. Such schemes can be considered in the distance and directional overcurrent relays (D&DOCRs) coordination to achieve faster ...

in this paper, an interval approach is presented to achieve perfect selectivity and maximum sensitivity in distance relay zones, considering uncertainties. for this purpose, first, the uncertainties affecting the settings of the three zones of a distance relay are discussed. then, by using the monte-carlo simulation, the uncertainties are modelled and the impedances seen by the distance relay a...

Most studies in relay coordination have focused solely on coordination of overcurrent relays while distance relays are used as the main protection of transmission lines. Since, simultaneous coordination of these two types of relays can provide a better protection, in this paper, a new approach is proposed for simultaneous coordination of distance and directional overcurrent relays (D&DOCRs). Al...

The undesired operation of zone 3 may be one of the most conspicuous protective relay features due to the incorrect zone 3 relay operations which have been conducive to the severity of blackouts. Therefore, determining the accurate zone 3 setting of the distance relay is deemed to be necessary. This paper focuses on the development of a new technique for calculating zone-3 setting of distance r...

In this paper the effect of presence of wind farms on relay coordination at fault condition and transient response at reclosing condition is studied. Wind farms as one of the important distribution generations (DGs) are so effective on overcurrent relay coordination in power systems. As well as Wind farms cause to severe oscillations on voltage, power and frequency in power system after reclosi...

This paper presents optimal coordination of overcurrent relays by using artificial bees colony algorithm. The objective function of the relay coordination problem is to minimize the operation time of associated relays in the systems. The control variables used in this paper are the pickup current and time dial setting of relays. The proposed method was tested with four systems study consists 5-...