This tutorial introduces the audience to the mathematical background and the implementation of distribution systems dynamic models within open-source power system simulators in the frequency domain. The mathematical content of this tutorial is reviewed for the audience’s awareness of the existing models for representing traditional equipment, such as synchronous machines, and non-traditional devices, such as Inverter Resources (IBR). This introduction will reveal the constraints and requisites for their implementation in computational simulation tools. The implementation of both traditional and non-traditional equipment will be examined using EPRI’s open-source distribution system simulator, OpenDSS, describing the sequence of events for obtaining a successful dynamic simulation, which later is verified with a practical example.