Abstract: At the time of power swing the measured impedance lies inside the relay operating region. There is undesired tripping of Distance relay during power swing without having any fault. So relay must be blocked & must trip after a fault occur during power swing. This paper presents new technique to detect fault during power swing. In the proposed technique process starts by simulating the double transmission line with one line series compensated. When we connect a fixed capacitor in one transmission line, fault detection become more difficult. The detection of symmetrical fault during swing is more difficult. So the proposed technique can easily detect any fault during swing with series compensated line. Sampled data of current and voltage passes through wavelet transform. It decomposes it into different levels. Then we calculate total energy of some selective levels of current and voltage. A double circuit line model is simulated in EMTDC/PSCAD.