Decision tree approach for fault detection in a TCSC compensated line during power swing

•Protection issues of TCSC compensated line during power swing.•A novel protection algorithm based on decision tree is proposed which uses three phase current signal to detect the fault during power swing in a modified WSCC nine bus three machine system.•This proposed method sensitivity is also tested in a New England IEEE 39 bus bigger system during power swing condition.•Use of the DT based technique for detecting fault in complex TCSC compensated transmission line during power swing is presented here for the first time.•This DT based algorithm is very sensitive for major fault cases like close in fault, CT saturation, high resistance far end fault during power swing. Also this algorithm does not respond any non fault event. Detection of fault in a thyristor-controlled series capacitor (TCSC)-compensated transmission line is more difficult compared to normal transmission lines. The fault detection problem becomes further complicated in such lines, especially during power swings. In this paper, a new approach is proposed for detecting fault during power swing in a TCSC-compensated transmission line, using only local end current measurements as input to a decision tree (DT)-based classifier. It is the first-ever use of the DT-based method for this application. The performance of the proposed method has been validated on numerous test cases generated on the WSCC 9-bus 3-machine system and the modified IEEE 39-bus New England system through EMTDC/PSCAD by varying the different parameters such as fault resistance, fault type, fault location, fault inception angle, firing angle of the TCSC, load switching, current transformer saturation, etc. The sensitivity of the proposed fault detection technique is found to be 100%, which is superior compared to the existing methods. Thus, justify the effectiveness of the proposed method.