Impact of a wave farm on its local grid: Voltage limits, flicker level and power fluctuations

Significant electrical power fluctuations in the range of seconds may be generated by most oscillating wave energy converters without significant amounts of energy storage capacity. Because of these fluctuations, a wave farm may have a negative impact on the power quality of the local grid to which it is connected. Hence, the impact of these devices on both distribution and transmission networks needs to be well understood, before large scale wave farms can be allowed to connect to the grid. This paper details a case study on the impact of a wave farm on the distribution grid around the national wave test site of Ireland with respect to voltage and power fluctuations, as well as regarding flicker levels. The electrical power output of the oscillating water column (OWC) wave energy converters was derived from experimental time series produced in the context of the FP7 project “CORES”. The results presented in this paper are based on a typical time series. Simulations were performed using DIgSILENT simulation tool “PowerFactory”.