An adaptive approach for three zone operation of digital distance relay with Static Var Compensator using PMU

•The effects of SVC on three zone distance relay protection are presented.•The proposed algorithm utilizes synchronized phasors measurement.•The proposed algorithm improves the accuracy of distance protection in presence of SVC.•PSCAD simulation results show the efficacy of the proposed algorithm.

Modern energy transmission systems suffer from great voltage dropping due to enormous loads. Therefore appropriate schemes should be devised to regulate the voltage. FACTS devices such as Static Var Compensator are often used for this purpose. However, SVC at mid-point of transmission line may leads to deteriorate of distance relay operation, resulting in inaccurate estimation of faults locations i.e. over-reach or under reach for different cases. This paper proposed a new algorithm that utilizes synchronized phasors measurement (SPM) to enhance the operation of distance protection zone in many aspects. The proposed method is tested for 230 kV system simulated in EMTDC/PSCAD with Bergeron model of transmission line. The results prevailed for adaptive approach scheme are more accurate, victor and robust in equivalence with usable transmission line distance protection with SVC.