This article presents a computational model used for time-domain analysis of the connection of energy resources that connect through power electronic converters in electric distribution networks. The model considers a three-phase voltage-source converter (VSC) with power and current controls in a synchronous reference frame. A Synchronous Reference Frame Phase Locked Loop (SRF-PLL) is used for synchronization. The distribution network is modeled with lumped parameters based on the short-circuit capacity at the connection point. To exemplify the possibilities, simulation results are presented with parameters from a real battery storage system currently in the commissioning phase on Cemig Distribuição's distribution network. Aspects such as voltage rise at the connection point under balanced load conditions and contributions to three-phase faults are evaluated. The model is implemented in the OpenModelica simulation environment, which is a free and flexible platform that provides the same characteristics to the model.