<span>This paper presents a</span><span lang="EN-US"> voltage </span><span>sensitivity analysis </span><span lang="EN-US">with respect to the real power injected </span><span>with</span><span lang="EN-US"> renewable energies</span><span> to determine the optimal integration of distributed generation (DG) in distribution systems (DS).</span><span> <span lang="EN-US">The best nodes where the power injections improve voltages magnitudes complying with the constraints are determined.</span></span><span> As it is a combinatorial problem, p</span><span lang="EN-US">article swarm optimization (PSO) and simulated annealing (SA) were used to change injections from 10% to 60% of the total power load using solar and wind generators and find the candidate nodes for installing </span><span>power </span><span lang="EN-US">sources. The method was tested using the 33-node, 69-node and 118-node radial distribution networks. The results showed that the best nodes for injecting real power with renewable energies were selected for the distribution network</span><span> by using the voltage sensitivity analysis</span><span lang="EN-US">. Algorithms found the best nodes for the three radial distribution </span><span>networks</span><span lang="EN-US"> with similar</span><span> values in the maximum injection of real</span><span lang="EN-US"> power</span><span>, suggesting that this value maintains for all the power system cases</span><span lang="EN-US">. The injections applied to the different nodes showed that voltage magnitudes increase significantly, especially when exceeding the maximum penetration of DG. The test showed that some nodes support injections up to the limits, but the voltages increase considerably on all nodes.</span>