Hybrid HVDC (H2VDC) System Using Current and Voltage Source Converters

Abstract

This paper presents an analysis of a new high voltage DC (HVDC) transmission system, which is based on current and voltage source converters (CSC and VSC) in the same circuit. This proposed topology is composed of one CSC (rectifier) and one or more VSCs (inverters) connected through an overhead transmission line in a multiterminal configuration. The main purpose of this Hybrid HVDC (H 2 VDC), as it was designed, is putting together the best benefits of both types of converters in the same circuit: no commutation failure and system's black start capability in the VSC side, high power converter capability and low cost at the rectifier side, etc. A monopole of the H 2 VDC system with one CSC and two VSCs-here, the VSC is the Modular Multilevel Converter (MMC) considered with full-bridge submodules-in multiterminal configuration is studied. The study includes theoretical analyses, development of the CSC and VSCs control philosophies and simulations. The H 2 VDC system's behavior is analyzed by computational simulations considering steady-state operation and short-circuit conditions at the AC and DC side. The obtained results and conclusions show a promising system for very high-power multiterminal HVDC transmission.

Evolution of the HVDC Link Connecting Offshore Wind Farms to Onshore Power Systems

“…The main benefits that come from such approach are lower losses compared to pure VSC (due to the LCC switching mechanism) or fact that many VSCs can be connected to a single LCC which may represent a more economic and robust investment (less switching devices). The hybrid topology has disadvantages such as managing of a DC link's discharge for reversed power flow [59][60][61]. Moreover, some aspects of the hybrid technology are technically challenging: higher insulation requirement on the wind turbines, selected electrical equipment of the WPP must be oversized to prevent over-voltages from occurring in the turbines [62].…”

Sistema HVDC Baseado na Conexão Série de Conversores Fonte de Corrente Comutados pela Linha e Autocomutados

“…Guo et al (2012) propuseram uma conexão híbrida de LCC-HVDC e VSC-HVDC no mesmo barramento, aumentando a relação de curto circuito equivalente (SCR) do sistema CA. Lebre et al (2018) apresentaram uma configuração híbrida usando um conversor LCC na estação retificadora e um conversor MMC (Modular Multilevel Converter ) na estação inversora. Além de mitigar falhas de comutação na estação inversora, a conexão proposta facilita a configuracão multiterminal.…”

Analysis of the Incidence of Direct Lightning over a HVDC Transmission Line through EFD Model

“…Since then, these technologies have been perfected and gaining larger applicability. There are currently more than 200 HVDC systems in operation worldwide and technological advances continue to arise [10].…”