Paper Title
Steady State And Fault Analysis In Hvdc Transmission Network Based On Hybrid Cascaded Multilevel VSC

Abstract
The evolution of high-voltage fully controlled semiconductor technology has significant impact on efficient management of electrical grids. This paper proposes a high-voltage DC (HVDC) transmission systems based on a hybrid multilevel voltage source converter (VSC) with ac-side cascaded H-bridge cells. It deals with the control of Multilevel VSC- HVDC, the use of VSC-HVDC in a large network consisting of a bipolar transmission system. The objective of the work is to assess the performance of a VSC-HVDC with ac-side cascaded H-bridge cells during DC pole to pole fault. A control system is developed combining an inner modulator and capacitor voltage balancing controller, an intermediate current controller and an outer active and reactive power controller. The control strategy based on PI and Fuzzy are studied and simulated in MATLAB / SIMULINK