This is the peer reviewed version of the following article: Jovcic D., Zhang H., Findlay D., Annuar A. Z., and Li B. (2017) Subsea DC collection grid with high power security for offshore renewables, Int. Trans. Electr. Energ. Syst., 27: e2249, which has been published in final form at DOI: 10.1002/etep.2249. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.