Picture of smart phone in human hand

World leading smartphone and mobile technology research at Strathclyde...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including by Strathclyde researchers from the Department of Computer & Information Sciences involved in researching exciting new applications for mobile and smartphone technology. But the transformative application of mobile technologies is also the focus of research within disciplines as diverse as Electronic & Electrical Engineering, Marketing, Human Resource Management and Biomedical Enginering, among others.

Explore Strathclyde's Open Access research on smartphone technology now...

A low-loss hybrid bypass for DC fault protection of modular multilevel converters

Gowaid, I. A. (2016) A low-loss hybrid bypass for DC fault protection of modular multilevel converters. IEEE Transactions on Power Delivery. ISSN 0885-8977

[img]
Preview
Text (Gowaid-IEEE-TOPD-2016-A-low-loss-hybrid-bypass-for-DC-fault-protection)
Gowaid_IEEE_TOPD_2016_A_low_loss_hybrid_bypass_for_DC_fault_protection.pdf - Accepted Author Manuscript

Download (1MB) | Preview

Abstract

Without additional circuitry, the half-bridge modular multilevel converter (HB-MMC) is endangered under dc side faults. Typically, a bypass thyristor is augmented to each HB cell to take up fault current until ac circuit breakers interrupt the dc fault. This paper proposes a dc fault protection concept for HB-MMC stations that requires insignificant extra silicon area relative to the thyristor bypass concept. Herein, bypass thyristors of typical HB cells are rearranged such that an independent modular shadow rectifier bridge (SRB) is formed. A low-loss switch assembly is utilized to immediately isolate the MMC following fault detection and the SRB suppresses the fault current by injecting a reverse dc voltage. Among several advantages, the proposed arrangement incurs insignificant losses in steady state, and the MMC is capable of operating in STATCOM mode briefly after fault inception to support ac grid voltage. The proposed concept may be suitable for clearing temporary faults on overhead HVDC lines. Several structural variations will be viewed and discussed. Applicability for twolevel VSC will be addressed. The concept is validated by detailed numerical simulations of a ±200kV HB-MMC station under dc fault.