In power systems, it is challenging to identify the faulty line and fault distance when compensating devices are present in the system. This work presents a fault locator using an Adaptive-Network-based Fuzzy Inference System (ANFIS) that accurately estimates the fault location on a compensated line in conjunction with an active power dierential-based backup protection algorithm for faulty line identication. Both the faulty line identication algorithm and the ANFIS-based fault locator utilise the positive and negative sequence voltage and current phasors generated by the Phasor Measurement units (PMUs) placed in the system. The ANFISbased fault locator is trained and tested using the simulated fault data obtained with a MATLAB Simulink model of a modied WSCC 9 bus system. The training data is generated by varying the fault distance in steps of 10 km. The line-to-line resistance (Rf) of 0.01 Ω, 0.1 Ω & 1 Ω, and the line-to-ground resistance (Rg) 1 Ω, 10 Ω & 100 Ω are used with dierent types of faults (LG, LLG, LLLG, LL& LLL) for training. Two ANFIS structures are trained for the fault distance estimation in compensated line -one for Static Synchronous Compensator (STATCOM) and the other for Static Synchronous Series Compensator (SSSC). Simulation results show the fault locator estimates the fault location accurately with a 5% tolerance in all the fault conditions simulated.