Transient signals are found in many areas of interest, where they provide information about the analyzed system. One of these areas is given by power engineering applications. The predictive maintenance of the electrical infrastructures is based on the study and characterization of the partial discharge activities. Detecting these phenomena is a complicated task and currently there are various theoretical and practical studies designed to deal with partial discharges. Despite the many approaches proposed, there is no precise method of describing this phenomenon. Thus, our paper presents a new approach based on the evaluation of transient phenomena detected in a power grid, through the entropy of the system in phase space. Also, using a set of spatial descriptors, the partial discharges will be able to be properly characterized.