Potential of Wind Farms Connected to HVdc Grid to Provide DC Ancillary Services

DC grids will require ancillary services to compensate for uncertainties, such as disturbances and converter outages. The appropriate equipment behavior and the sources of these services consequently need to be defined. This paper describes the reaction, activation, and provision intervals of ancillary services for dc grids to maintain the dc voltage in a certain range. It also discusses how wind power plants and synchronous generators that are exclusively connected to a dc grid can comply with these requirements. The theoretical descriptions are validated using simulations.