This paper explains how distribution grid renewable integration and protection studies are conducted using a digital real-time simulator (DRTS). Distribution grids are difficult to simulate in real-time because they are very large and have only short lines, making the parallel calculation of the equations particularly difficult. The SSN solver is an Electromagnetic Transient (EMT) solver used to compute the time-domain solution of these large distribution networks in real-time. The SSN solver is able to handle networks with more than 750 nodes without the use of Bergeron-type line models and without artificial delays added. A real-life distribution grid, from ENEL Distribuzione, is used to explain these concepts and check the real-time performance of the SSN solver. Other distribution cases using EMT and real-time phasor type solvers are also presented.