This paper analyze the voltage profiles in power distribution networks with different levels of small-scale PV systems. The grid-connected PV system is one of the most promising renewable energy solutions which could offer many benefits to both the end user and the utility network, adistribution network model has been developed in MATLAB/Simulink and implemented to evaluate the voltage profiles and power flow for different levels of PV systems. This will help in evaluating the impact of high penetration levels of small-scale grid connected PV systems on the power quality for a residential distributed network in the UK. Different penetration scenarios and variable load conditions are considered. The result obtained confirmed that maintaining a stable operation and an acceptable power quality in distribution networks are possible with a wide range of PV penetration levels.