This paper presents an experimental voltage quality analysis affected by passing clouds based on results attained from monitoring a 9.5-kWp photovoltaic grid connected. This system is composed of three 3.2 kWp subsystems installed on the flat roof of the Renewable Energy Development Institute (CDER) in Algeria. In this paper we analyzed and evaluated Short-term and long-term voltage flicker indexes (Pst,Plt), power ramp event on voltage quality, harmonics caused by inverter and by the loads connected to the PCC, and very short voltage variation (VSV). The power quality parameters at the inverter output side have been measured using CA8335 power quality analyzer. The results show that the change in the density of the passing clouds has a linear relationship with the change in the intensity of the ramp event on the power generated by the PVS. Moreover, in the case of a bidirectional electrical network and with the presence of non-linear loads, the flicker recorded has exceeded the legal limits, due the second-order harmonics effects generated by non-linear loads and the level impedances at the grid and the PV system connection point. The concluded results obtained can be an additional profit of for the electricity distribution networks in Algeria, upon in the light of the diffusion of promoting photovoltaic systems.