Fault-tolerant structure for cascaded H-bridge multilevel inverter and reliability evaluation

作者：Haji Esmaeili Mohammad Mehdi; Naseri Mersad; Khoun Jahan Hossein; Abapour Mehdi

来源：IET Power Electronics, 2017, 10(1): 59-70.

DOI：10.1049/iet-pel.2015.1025

• invertors
• failure analysis
• fault tolerance
• cascaded H-bridge multilevel inverter
• fault-tolerant structure
• reliability evaluation
• defective module
• module circuit
• controlling circuit
• healthy modules
• system failure

In this study, a fault-tolerant structure and its controlling method for a cascaded H-bridge multilevel inverter is introduced. When a fault occurs in one of the modules, the proposed circuit is able to isolate and eliminate the defective module from the whole system. The isolation and elimination is done by four relays in each module and a controlling circuit. This solution makes the system continue the normal operation by means of the remained healthy modules with decreased output voltage level. Therefore, the whole system failure will be prevented and higher reliability of the inverter will be guaranteed. Principles of operation and the controlling method are presented in this study. Reliability evaluation and comparison of the proposed fault-tolerant structure and the conventional one are considered. To ensure the correct performance of the proposed cascaded H-bridge multilevel inverter, a prototype has been synthesised in the laboratory. The obtained results affirm higher reliability and mean time to failure of the proposed circuit, so suitability of the proposed structure for sensitive industrial applications is confirmed.

• 出版日期2017-1-20