Zero‐sequence voltage injected fault tolerant scheme for multiple open circuit faults in reduced switch count‐based MLDCL inverter. Issue 8 (21st May 2018)

• Record Type: Journal Article
• Authors: Vemuganti, Hari Priya; Sreenivasarao, Dharmavarapu; Siva Kumar, Ganjikunta
• Is Part Of: IET power electronics. Volume 11:Issue 8(2018)
• Page Start: 1351
• Page End: 1364
• Publication Date: 2018-05-21
• Subjects: fault tolerance -- invertors -- bridge circuits; nine‐level MLDCL inverter -- fault conditions -- three‐phase 15‐level MLDCL inverter -- uniform power sharing -- balanced line voltages -- phase angle -- magnitude angle -- generalised mathematical equations -- NS zero‐sequence injection FTS -- RSC‐based MLDCL inverter -- RSC‐based multilevel dc‐link inverter -- reduced switch count‐MLI -- zero‐sequence injection FTS -- CHB -- cascaded H‐bridge -- multilevel inverters -- FTO -- fault tolerance operation -- neutral shifting -- reduced switch count‐based MLDCL inverter -- multiple open circuit faults -- zero‐sequence voltage injected fault tolerant scheme; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2017.0472
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : Neutral shifting (NS) is a popular scheme to achieve fault tolerance operation (FTO) of multilevel inverters (MLIs) such as cascaded H‐bridge (CHB). This fault tolerance scheme (FTS) can be realised with/without zero‐sequence voltage injection. Among these, NS with zero‐sequence injection FTS is relatively easier to implement. However, this scheme is not generalised for multiple open‐circuit faults. Moreover, NS‐FTS schemes are not directly applicable for fault tolerance of reduced switch count (RSC)‐MLIs, as these inverters have limited redundancies. Therefore in this study, FTO for RSC‐based multilevel dc‐link (MLDCL) inverter using NS zero‐sequence injection FTS is proposed for simultaneous failure of multiple switch faults. Generalised mathematical equations are derived to calculate the magnitude and phase angle of injected zero‐sequence voltage for obtaining balanced line voltages with uniform power sharing among all healthy units. The proposed generalised NS‐FTS with zero‐sequence injection is implemented on three‐phase 15‐level MLDCL inverter for various fault conditions. The obtained simulation results are validated experimentally on nine‐level MLDCL inverter.