Voltage Regulation and Reactive Power Control Units for the Grid Integration of Renewable Power Generation in Distribution Networks

Due to increasing power infeed of highly volatile energy sources connected to distribution grids, innovative grid regulation units are needed to ensure grid stability and fulfil grid codes. The ability of photovoltaic and wind power plants to regulate the reactive power flow and therefore to prevent voltage swells generally depends on the supplying grid voltage. Especially in medium voltage grid areas with long cable extensions, low short-circuit power and fluctuating power flows, grid codes at the connecting point widely cannot be met. In this regard a simple and applicable solution can be found in Voltage Regulating Distribution Transformers (VRDT) using on-load-tap-changer (OLTC). Initially designed to be used as a control device to provide flexibility and adjustments between medium and…