Reactive Power Control in Distribution Networks to minimize the Reactive Power Balance at the Point of Common Coupling

Due to the shutdown of conventional power plants and a higher penetration of distributed generation units in the distribution system, the demand of reactive power supply through distributed generation units is increasing. Since conventional power plants used to provide reactive power for voltage control, distributed generation units have to substitute them now. Nowa-days different characteristics for a reactive power control of DG Units are already considered by the Distribution Grid Operator to support the voltage control in the Transmission Grid but also to keep the reactive power flow inside the contractually defined limits. Changing grid codes for receiving a higher flexibility in the grids are underlining the importance. This paper describes different strategies for the reactive power control of DG-units to reduce the reactive power balance between the Medium and the High Voltage Level at the point of common coupling by using time series simulation.