Modelo para Simulação de Limitador de Curto-Circuito de Núcleo Saturado

Abstract

With the advent of new sources of power generation, among them the renewable ones,there has been a significant change in the power grid profile, especially for the distribution sectors. Thus, substations (SEs) with obsolete equipment find it difficult to meet the growing and diversified demands for energy, and a reflection of this problem is the significant increase in the levels of short-circuit currents. The short-circuit current limiter (SCCL) appears in this scenario as a protection equipment that can help, along with other components, in limiting the short circuit and minimize this problem. Among the several existing SCCL topologies, there is the saturated core current limiter (SCCL-SC) with its operation based on the dynamic characteristics of the ferromagnetic materials that compose its cores. This paper describes the extension of a single-phase modeling, in MATLAB software, of the LCCC-NS to simulations on three-phase electrical networks. The results prove the influence of the DC magnetic flux in the initial instants of a single-phase short circuit, due to the approximations considered for the three-phase model. However, when compared with measurements performed in the laboratory, the three types of DC current tested in the three-phase model of the limiter responded satisfactorily in the moments after the short circuit.