Hybrid transient based protection scheme for distribution grids supplied with distributed generation

Abstract

The integration of distributed generation (DG) transforms current distribution networks from vertically operated to horizontally operated. This transition leads to problems related to protection coordination. In the future, new protection philosophies should be applied which guarantee the increase of the distributed generation availability during faults.
The paper presents a hybrid transient based protection scheme based on wavelet transform
coefficient (WTC) analysis. Numerous cases are simulated indicating that the protection
principle works reliably independent from the distributed generation presence. Simulations
are carried out using ATP/EMTP software package and the generated data are processed by applying wavelet transform within Matlab environment.
Keywords: discrete wavelet transform, distribution networks, distributed generation,
protection