Impact of distributed generation on transient-based fault location techniques in distribution networks

This paper demonstrates the effect of conventional distributed generation (DG) on fault location techniques based on transient signal analysis. DG penetration in distribution networks deviates the route-specific frequencies generated by fault traveling waves propagating along the feeders and laterals. The amount of these deviations is proportional to the rated power of a certain DG unit. A validated fault location procedure is used to clarify this effect. Fault-generated voltage transient signals are analyzed using continuous wavelet transform (CWT). These signals are captured by a recording device generally placed at the main feeder supplying the distribution systems. The route-specific frequencies are acquired by the wavelet amplitude spectrum of transient signals. Using this technique, the relevance between the CWT-recognized specific frequencies and those attained by mathematical definition determines the fault position. A six-bus radial test distribution feeder is simulated within the EMTP-RV program, and analysis of relevant transient signals is carried out using MATLAB programming language.