CO-ORDINATION OF THE OPERATION OF THE RELAY PROTECTION AND SURGE PROTECTIVE DEVICES IN ELECTRICAL POWER NETWORKS MEDIUM VOLTAGE 20 kV

Mediha Hamza - Margreta Vasileva - Marinela Yordanova

   The paper presents a model of electrical power network $20\,$kV in MATLAB Simulink and results based on it. The aim of the paper is to research the co- ordination of the operation of the numerical relay protection and surge protective devices in these grids. The researches are fulfilled in case of a direct stroke of a single or repeated lightning over the phase conductor of an overhead power line at different relay protection settings. The recommendations about the setting up of quick operating relay protection and energy capability of the metal oxide surge arresters are given based on the model researches in MATLAB Simulink.

Keywords: lightning overvoltages, metal oxide surge arrester, numerical relay protection

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