Energisation Method for Offshore Wind Farms Connected to HVdc via Diode
Rectifiers
Abstract
Diode rectifiers (DRs) have been recently suggested as a viable
alternative for connecting offshore wind farms (OWFs) to HVdc, eliciting
growing interest from both industry and academia. However, energisation
of DR-connected OWFs is not straightforward. The present study
constitutes a proof of concept of a novel energisation method for
DR-connected OWFs, in which auxiliary power is provided from the shore
through the HVdc link and the dc bus bar of one or more WTs. The
proposed method provides an alternative with minimal additional
hardware, which can be easily extended to more WTs in the OWF,
increasing reliability by providing redundancy. The study includes
coinciding auxiliary loads with active and reactive power components and
a semi-aggregated OWF model, in which every WT is individually
represented in the string containing the energising WT. Two additional
sequences of simulation events are considered following the initial
energisation sequence. Such sequences comprise wind power taking over
the provision of the auxiliary power and the run-up to maximum
(available) power production. The simulation results indicate that the
proposed method is a suitable alternative for energising OWFs connected
to HVdc via DRs.
The manuscript has been submitted to
IEEE Transactions on Power Delivery.