Integral control of a Multi-Terminal HVDC-VSC transmission system

Abstract

This paper proposes a control structure of a Multi-Terminal HVDC (MTDC) system employing Voltage Source Converters (VSC) technology. The study focuses on high-level control to keep DC voltage stable, mitigate oscillations due to the change in incoming power produced by contingencies in the AC grid and to provide the system with an adequate dynamic response [1]. Apart from this, controllers need to be validated in terms of HVAC grid compliance and for this purpose the UK National Grid Code will be used for verifying the fulfilment of frequency/voltage response and Low Voltage Ride-Through (LVRT). Thus, different tests will be performed considering the MTDC control objectives and the Grid Code compliance.