A New Method For Locating The Source Of Lightning Transients

Power system transients are power quality disturbances that can be harmful especially to electronic equipment. This paper presents a new method to locate the source of lightning transient relative to the monitoring point. The proposed method is based on complex wavelets energy which is calculated from the voltage and current data obtained at the monitoring point. The data is transformed to its complex wavelet counterpart. The transient power is first calculated and the complex wavelet energy is obtained by integrating the transient power. From the wavelet energy plot against time, a change in wavelet energy from an approximately zero to a negative value indicates that the transient source is from downstream or in front of the monitoring point. On the other hand, a change in wavelet energy from an approximately zero to a positive value indicates that the transient source is from upstream or behind the monitoring point. To verify the proposed complex wavelet method, simulations using the PSCAD/EMTDC software have been performed. Lightning strikes in a PSCAD library model have been adapted for the impulsive transient simulation. Simulation results prove that complex wavelet energy is capable of locating accurately the source of transients in a power distribution system.