Ultra-high-speed protection for medium voltage distribution networks with distributed generation

In this work two protection schemes are proposed in order to improve the integration of distributed generation and to take advantages of its potential benefits. A protection algorithm for fault classification has been developed, as well a directional comparison scheme is proposed. The protection schemes are based on high frequency components generated by fault, so that the schemes show characteristics of ultra-highspeed operation. For both schemes, the discrete wavelet transform based on the Haar wavelet has been used as a preprocessing tool for three-phase current signals. In addition, an artificial neural network is used as support for the task of fault classification. The proposed algorithms are performed by using MATLABtrade environment. In order to evaluate the scheme responses, a test distribution network under various fault conditions has been simulated by ATP/EMTP software.