Multi-terminal VSC-HVDC system for integration of offshore wind farms and green electrification of platforms in the North Sea

Abstract

This paper discusses a multi-terminal VSC-HVDC system proposed for integration of deep sea wind farms and offshore oil and gas platforms in to the Norwegian national grid onshore. An equivalent circuit of the VSC in synchronous d-q reference frame has been established and decoupled control of active and reactive power was developed. A three terminal VSC-HVDC was modeled and simulated in EMTDC/PSCAD software. Voltage margin method has been used for reliable operation of the HVDC system without the need of communication. Simulation results show that the proposed multi-terminal VSC-HVDC was able to maintain constant DC voltage operation during load switchings, step changes in power demand and was able to secure power to passive loads during loss of a DC voltage regulating VSC-HVDC terminal with out the use of communication between terminals.