Design and Evaluation of a Tidal In-Stream Generator Power Port

Oceanic currents and tidal streams are a predictable and vast source of energy. The astronomical nature of the underlying forces causing such streams, results in speed variations that change at certain time intervals. There are different methods for harnessing part of this vast and renewable source of energy; however, regardless of the method used, integrating a large-scale tidal in-stream energy converter into a conventional power system poses many challenges, in particular, in weaker networks. Injection of the captured stream power to a nonstiff network changes the magnitude of the voltage at different times of the day. The impact on the voltage magnitude is commonly most critical if tidal generators and consumers share the same medium voltage feeder, which is a case that seems inevitable especially when considering the electrically remote but energy-rich areas of estuaries, oceanfronts, and natural water channels. This investigation provides designing details of a hybrid power port solution that establishes an independent active and reactive power control, enabling it to regulate the point of common coupling voltage, while transferring variable amounts of captured stream power to a nonstiff grid. To verify the feasibility of the proposed scheme, an example system is designed and tested using a common tidal stream power profile. This investigation is a timely contribution to the emerging field of marine current power generation.