Rung Punyachai creator Weerakorn Ongsakul Chairperson Singh, Jai Govind Examination Committee Dhakal, Shobhakar Examination Committee PEA Scholarship donor Asian Institute of Technology Education Cooperation Project Scholarship donor Asian Institute of Technology Fellowship Scholarship donor text series technical report th Pathum Thani, Thailand Asian Institute of Technology 2014 continuing eng 74 leaves : ill. + 1 online resource This thesis provides an assessment on voltage profiles of a distribution system in the presence of high level of solar rooftop PV penetration. Each household solar rooftop PV power generation is calculated by PVWATTs online calculation tool. Average load profile in northern part of Provincial Electricity Authority (PEA) of Thailand is selected for the simulation. Simulation results indicate the maximum allowable PV installation per house in which voltage level do not exceed standard operating limits . Finally, optimal voltage regulation strategy using particle swarm optimization (PSO - Q(U) method ) is used to minimize the total inverter reactive power injection subject to power balance equation, inverter reactive power injection limits, and voltage limits are shown. Test results on the 19 buses radial system indicate that the total inverter reactive power injection of PSO - Q(U) method is lower than the simple Q(U) method , leading to a higher real power output capability of solar PV inverter. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Energy Thesis (M.Eng.) - Asian Institute of Technology, 2014 Photovoltaic power systems Thailand, Northern Solar energy Thailand, Northern Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B02304 http://203.159.5.9/ait-thesis/detail.php?q=B02304 170831 20260818134345.0