Improved Coordinated Control of AVM based Multi-Terminal HVdc System using Steady-State Analysis.

Modular Multilevel Converter (MMC) with the addition of average voltage model (AVM) has increased the efficiency, performance and scalability for voltage source converter (VSC) within multi-terminal high voltage direct current (MT-HVdc) network. When this technology is integrated into the large HVdc transmission system, electromagnetic-transients (EMT) complicates the study of transient's states. Unlike complex modelling, a simple and better understanding of the AVM in VSC stations helps to improve the dynamic control performance in the large transmission system hence, improving steady and transient states. This paper presents the solution, by using state space analysis of a four terminal test grid, to optimize control parameters of VSC stations. In order to validate the desirable performance of AVM under dynamic states, practical scenarios have been simulated using PSCAD/EMTDC software. Simulation results are presented and its state-space analysis is also studied. [ABSTRACT FROM AUTHOR]