Protection system planning for distribution networks: A probabilistic approach

Abstract This paper presents a multi-objective optimization approach to perform the allocation, sizing and coordination of control and protective devices in distribution networks with different types of distributed generation. The model consists of three objective functions that consider investment costs, the system’s non-supplied energy, and average interruption duration index. We use a probabilistic short-circuit routine to evaluate the currents values, taking into account the uncertainties of renewable power generation and the system’s loading, as well as the fault’s parameters randomness. The probabilistic approach allows the correct planning of the protection system and enables the user to admit some risk of not coordinated operation, aiming to reduce the solutions’ costs. This multi-objective mixed-integer non-linear optimization problem considers the possibility of load transfers from neighboring feeders and intentional islanding. In this paper, we use the Non-dominated Sorting Genetic Algorithm to solve this optimization problem. The algorithm is tested for a 135-bus feeder.