Adaptive current protection in electrical complexes with small power plants

Abstract

The article considers electrical complexes with power plants of small capacity. The influence of power generation sources on short-circuit current distribution has been investigated. Reduced sensitivity of back-up current protection and dependence of current distribution on power plant capacity are revealed. Recommendations for minimizing false operation of short-circuit protection in networks with distributed power generation are proposed. An algorithm for adaptive current protection, which uses graph theory to determine the stages of selectivity of relay protection based on finding the shortest Dijkstra path and calculation of equivalent resistance in networks with multiple sources of power generation, which provides selec-tivity and sensitivity of current protection when changing the generated power of generators and the structure of the distribution network is pre-sented. The algorithm uses communication lines with a central control unit to monitor the distribution network and update the current triggering of the relay protection in accordance with changes in the structure of the power grid. The proposed system is designed so that it can respond to dynamic changes in the structure of the network and the state of operation of power plants. Simulation modeling in the Matlab/Simulink software package was performed and the results of the algorithm are presented.