Analysis of VSC-HVDC Power Transmission Systems against Atmospheric Impulses

Abstract

This research proposes an analysis on direct current transmission systems performance (High Voltage Direct Current - HVDC) against electromagnetic transients resulting from atmospheric impulses. Different network topologies (monopolar, bipolar and multi-terminal) and voltage source converters (VSCs) behavior are evaluated from atmospheric impulse incidence on the alternating current AC grid terminal as well as on the HVDC link connect to the DC converter terminal. Based on results obtained from modeling and computational simulation of different VSC-HVDC topologies, the lightning protection is evaluated by using conventional metal-oxide varistors at AC and DC converter terminals, highlighting that such protection method is well established only for HVDC systems composed of line commuted converters (LCC) applied for point-to-point power transmission through long distances. In this context, a careful analysis is proposed on technical and operational characteristics of modern VSC-HVDC systems response against electromagnetic transients resulted from steep-front impulses, since such subject is practically unexplored in the classic and recent technical literature. (AU)