Um sistema de proteção de sobrecorrente adaptativa aplicado a sistemas de distribuição de energia elétrica.

Abstract

A novel adaptive directional overcurrent protection system for electricity distribution networks, considering the presence of distributed generation is proposed. The modular system was developed in two stages of operation: system monitoring and calculation of new protection settings. The system supervises the state of the electrical network through the monitoring and processing of the analog and digital channels of the relays, obtaining as a result the variation of the states of the circuit breakers and the active power of the distributed generators, which are used as indicative of changing the scenario of operation. As a contribution, the monitoring of these parameters indicates changes in state from faults and power in distributed generation. In case of identification of change of scenario, the proposed system recalculates the optimum settings of the overcurrent protection using a microgenetic algorithm. The use of this algorithm is proposed in view of the fact that it applies well to the protection problem since processing time is a crucial issue. For validation purposes, the proposed system was developed in a MATLAB® environment and evaluated under the perspective of several operational scenarios and penetration levels of distributed generation. For this, the IEEE 34 node feeder was used. Then, the performance of the proposed system was compared with an adaptive protection system based on genetic algorithm and the conventional protection system. In accordance with the results presented, it was possible to conclude the efficiency of the proposed system in terms of both processing speed and selectivity.