State-space embedding as a visualization method for mixed partial discharge activities

It has been known for a while now that partial discharge patterns can be described in terms state-space trajectories that are reconstructed from sequences of measured PD-related quantities such as PD magnitude, phase angle or voltage difference between pulses. The trajectories form geometrical patterns that can be related to the type of PD source for single-source signals. In this article, we show that distinct patterns of mixed PD sources are discernible in state-space trajectories. This observation indicates a new possible direction in the approach to solving the problem of PD source separation.