Reliability analysis of offshore grids-An overview of recentresearch

摘要

For the future, a large-scale expansion of offshore wind energy is expected inEurope. To collect this wind energy and to enable electricity trading between countries,an offshore network will be implemented in the North Sea. Maintaining ahigh level of security of supply at affordable costs is one of the key objectives inthe design and operation of power systems and therefore, the reliability of offshoregrids is an important topic of discussion. Whereas onshore, the security of supplyis assured by reliability criteria like n-1 redundancy, the same n-1 redundancymight not be an economical solution for offshore networks. For todays (small) offshorenetworks, n-1 redundancy is hardly economically justifiable, seen from awind farm owner's point of view. The question then arises how the reliability oflarge-scale offshore networks should be evaluated and what measures can be takento maintain a high security of supply onshore. This paper aims at discussing thistopic by reviewing the results of recent research work. It is found that whereas forsmaller offshore networks reliability evaluation is mainly an economic analysisseen from a wind farm owner's point of view, for large-scale offshore networks,it is necessary to consider the interaction of offshore–onshore networks in reliabilityanalysis. It is proposed to analyze the reliability of combined offshore–onshorepower systems in an integrated approach, such that various (offshore and onshore)measures can be considered to find the most economical solution.