Voltage control by means of smart transformer in medium voltage feeder with distribution generation

The integration of uncontrolled distributed generation (DG), like photovoltaic and wind turbines, and the growing amount of connected loads in the medium voltage (MV) grids have worsened the voltage variability, and in extreme cases violating the voltage limits. New mechanism and control action for supporting the voltage must be adopted, due to the unpredictability of these resources. The power electronics-based smart transformer (ST) can provide ancillary services to the distribution grid without the installation of additional devices, and among them the voltage and reactive power control. This paper illustrates, through simulation in PSCAD, the ST capability in controlling the voltage profile within the safe operation limits.