Detection of operational-mode of TCSC using positive sequence technique

The paper concentrates on mode of operation of Thyristor Controlled Series Compensation (TCSC) present in a line using positive sequence based techniques. The positive sequence based technique is taken into consideration as it is present in both balanced and unbalanced fault conditions. Distance protection issues related to degree of compensation, high resistance fault and other fault conditions are addressed. Determination of MOV´s status at the time of fault is another issue which alters mode of TCSC operation. The performances of the proposed technique for various situations indicate the applicability of positive sequence superimposed algorithm (PSSA) to detect presence of TCSC mode of operation in fault loop. PSCAD/EMTDC generated data using 400kV transmission line with TCSC at staring point has been used to test the accuracy of algorithm.