The envisaged increased penetration of distributed generation (DG) In electrical power networks poses challenging technical and contractual issues to both utilities and industry. Technical issues related to power quality, in particular to voltage-sag propagation and characteristics in networks with a large penetration of fixed speed wind DG are addressed. A comprehensive analysis of voltage-sag propagation in a realistic distribution network is performed. The influence of network topology, location and percentage of connected wind generation, network loading and load composition is investigated in detail. It is shown that the influence of DG on voltage-sag characteristics and propagation is strongly dependent on its location and on load composition.