Stability studies for off-shore vsc-hvdc connected wind generation

Abstract

For some applications, High voltage direct current (HVDC) transmission systems are more suitable than conventional ac transmission. With recent advances in this technology and the controllability that it offers, Voltage SourceConverter basedHigh voltage direct current (VSC-HVDC) systems have proven to be a more advantageous choice for integration of renewable energy sources, mostly for offshore wind power plants which are generally located far away from the main grid. Their interaction with the onshore system influences the power grid stability and calls for different dynamic analysis. As well as conventional generation, VSC-HVDC connected generation units have to fulfil strict grid codes determined by the Transmission System Operator (TSO). Consequently, the impact on the grid stability that regulations such as frequency support, Fault Ride Through (FRT) or post fault active power recovery rate needs to be studied. This work aims to analyze the impact on of VSC-HVDC systems on the grid stability in response to large voltage and frequency deviations. The software tool PowerFactory is used as a platform for the studies, which original templates have been modified in order to include new ancillary services and control strategies. Through several case simulations, it was found that the implemented functionalities improved the VSC-HVDC dynamic performance.