Indirect Voltage Control (IVC) versus Direct Voltage Control (DVC) in distribution grids with renewable energy sources

The voltage control in grids with high intermittent voltage profile, as the distribution grids with renewable energy source, can be based on Indirect Voltage Control (IVC) or Direct Voltage Control (DVC). In the distribution level, there are innumerous issues that influence the voltage profile during the operation of an Intermittent Generator (IG), such as load conditions or system characteristics (for example, line impedance). In this paper, the results of a comparative analysis between IVC and DVC are shown for different grid conditions. This comparison is done in terms of the apparent power that each equipment requires to compensate the voltage at the Point of Common Coupling (PCC) of the generic distribution grid considered. An analytical grid modelling including the IVC and DVC is used to compare both controllers in terms of the apparent power to keep the PCC voltage controlled when different values of current are injected on the grid by an IG. Numeric results are presented to show the best solution in terms of the equipment rating.