Behaviour of multi-terminal grid topologies in renewable energy systems under multiple loads

Abstract

Decarbonisation policies adopted worldwide are leading to an increasing deployment of renewable energy sources. In Europe, the growing number of offshore wind farm projects calls for scrutinising merits and opportunities of their interconnection via multi-terminal links rather than conventional point-to-point connections. The semiconductor components used in the converters and the resistance of power cables are expected to introduce new power losses in the transmission system. In this study, star and ring configurations with four DC nodes of multi-terminal grid topologies for renewable energy integration are modelled by means of NEPLAN software. In order to address more interconnection options the authors examine several grid topologies having more than three interconnections. The simulation results of the different network configurations, the power losses level in particular, are compared and analysed. The simulations illustrate an increasing complexity of network operation and power balancing, from a low power up to the rated power capacity injected at the inverters terminals.