The use of multiphase PM synchronous machines associated with VSI drives appears to be a very efficient solution when a high level of reliability, compactness and acoustic behaviour is required. This kind of solution is for example very useful in naval propulsion systems. The paper deals with the optimal control of a 5-phase PM machine associated with a VSI under fault conditions. This work focus on the use of such a system in normal and fault operations. The studied fault operations are open circuited phase fault conditions. Previous works have shown that, with this kind of 5-phase drive, it is possible to determine optimal currents references which maximize the torque density and reduce the torque pulsations of the machine when one or two phases are open circuited. In this fault case, classical linear controllers (as PID for example) cannot provide a correct tracking of these optimal reference currents because they have a highly dynamical behavior. Using this optimal reference current generation, we propose in this paper to compare classical PID controllers with fixed band and adaptive band hysteresis controllers. This comparison is done using Matlab/Simulink simulation in the case of a 5 phase surface mounted permanent magnet machine in normal and open-circuited fault operations. Study results show that adaptive band hysteresis control allows a good tracking of these unconventional reference currents with a fixed switching frequency for the VSI. In this case of adaptive s band hysteresis control appears to be particularly efficient.< Leer menos