This paper presents a new space phasor modulation (SPM) scheme for the operation of the H-bridge multicell inverter under fault conditions. The topology of this inverter consists of several single-phase H-bridge inverters which can be independently bypassed if a fault is detected. As this action may result in an asymmetrical inverter topology, a new method based on the SPM is proposed to avoid voltage unbalances. Simulations and experimental results obtained in a five-level multicell inverter prototype validate the proposed fault-tolerant method. Copyright (c) 2007 John Wiley & Sons, Ltd.