Improving the voltage profile of a medium voltage grid using distributed generation units

In this paper the impact of photovoltaic (PV) system connected to the medium voltage distribution grid using three-phase three-level inverter and step-up transformer will be investigated. The PV inverter is capable to control active and reactive power independently. The impact to the grid voltage profile of both active and reactive power regulation of the PV system will be examined. In order to simplify the control scheme and improve the performance of the converters the p-q theory has been chosen due to the ability to compensate the reactive power of the load. The proposed electric power system was investigated via simulation results during steady state and transient response. The analysis will be focused on the grid voltage profile improvement regarding of the of the inverter´s active and reactive power injection.