Fault Recovery Strategy for Hybrid Cascaded H-Bridge Multi-Level Inverters


In the configuration of the multilevel inverter which is used in this study, two cascaded H-bridge cells are connected in series with each phase of a three-phase three-level neutralpoint clamped (NPC) inverter. The NPC inverter is fed by a single DC source; whereas, all of the cascaded H-bridge cells are supplied by capacitors. In this paper, in order to regulate the voltage across the H-bridge capacitors, a small fundamental harmonic is added to or subtracted from the original PWM reference of each H-bridge cell. In addition, the operation of the inverter during a fault in the cascaded H-bridge cells is studied and a method for recovery from fault and compensation of fault using the remaining H-bridge in the corresponding phase is proposed. This method allows acceptable operation of the inverter even when one of H-bridge cells is not functioning. Verification of the method using simulation shows the proper operation of the voltage capacitor regulation and strategy of fault recovery.

Meeting Name

26th Annual IEEE Applied Power Electronics Conference and Exposition (2011: Mar. 6-11, Fort Worth, TX)


Electrical and Computer Engineering

Keywords and Phrases

Cascaded H-Bridge; Fault Recovery; Fundamental Harmonic; H-Bridge Cells; H-Bridges; Multilevel Inverter; Neutral Point Clamped; NPC Inverters; Single DC Source; Three-Level; Voltage Capacitors; DC Power Transmission; Electric Inverters; Paper Capacitors; Power Electronics; Recovery; Inverters; Capacitors; Voltage Control; Circuit Faults; Harmonic Analysis; Pulse Width Modulation; Switches; Invertors; Network Topology

International Standard Book Number (ISBN)

978-1424480845; 978-1424480852

International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version


File Type





© 2011 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Mar 2011