Otimização da coordenação entre relés de sobrecorrente de tempo inverso através de heurísticas bio-inspiradas: uma abordagem utilizando os algoritmos dos lobos cinzentos e dos morcegos

Abstract

Relays have the function of identifying faults, locating them precisely and alerting the operation of the system to trigger the opening of circuit breakers, in order to isolate the defect, ensuring selectivity. The main and backup protection in the transmission systems are associated with overcurrent relays, more specifically overcurrent relays with minimum reverse time and directional relays. However, one of the problems arising from the use of these relays concerns to their coordination, which aims to obtain the optimum configuration of operation, so that the smallest number of consumers is left without the electricity supply in the case of their operation. In this context, optimization techniques are applied, such as the heuristic algorithms and the Lagrange Multipliers Method for solving the coordination of the overcurrent relays. The methodologies used in this Work to optimize the coordination of the relays are: the Grey Wolfes heuristic and the Bats Algorithm. In addition, the Lagrange Multipliers Method was used to validate the solutions obtained according to the heuristics for the problem formulated in its nonlinear form, since it returns the global optimum. In these methods, the inverse normal curve family of the Standard available by the International Electrotechnical Commission is used and the adjustments related to the time and current multiple are optimized, these parameters can be regulated in the relays installed in the power system. For the two test systems used, both algorithms were successful in coordinating the relays, maintaining the selectivity of the protection system, respecting the limits imposed by the variables, the minimum coordination interval and other adjustments imposed to the problem, proving to be effective performing the task of overcurrent relays coordination, replacing the traditional mathematical treatment.