The photo voltaic (PV) solar plants in weak grids, associated to industrial process has a unusual behavior of disconnection. If a suddenly changes of the grid frequency happens, in a single phase fault, in the high voltage transmission system; these variations in the frequency of the system could generate variations in the phase angle associated with the inverter control, called Phase Logic Lock (PLL), and this in turn generate an increase in the current through the inverters, causing a possible actuation of the instantaneous over-current protection. of DC/AC converter, in a massive failure. In this research article, the case study is evaluated with transient analysis of the grid, and Markov simulations with distributed parameters evaluation, in DigSilent with a large PV Solar plant proposed in the peruvian grid with 1200 simulations and evaluation of lightning discharge influence in the overhead lines.