Control and Simulation of DC/DC-Interconnected Multiterminal VSC-HVDC Grids

Abstract

This thesis addresses the control of multiterminal HVDC grids based on voltage-source converters interconnected via high-voltage DC/DC converters. In particular, it presents a new methodology to conceive a linear model of the aforementioned system taking into account the state of the art techniques. The grids are controlled by means of a current-based droop control designed through a multivariable frequency analysis considering the grid specifications. Furthermore, PI current controllers tuned by the internal model control technique are used for controlling the DC/DC converters. The model’s performance is evaluated and compared to its equivalent non-linear model through simulations of a case study employing actual infrastructure data