PUBLICATIONS

Double fed induction machine (DFIM) is preferred in various industrial applications, as it provides variable speed operation with

reduced power converter rating and high dynamic stability. On rotor side, back-toback voltage source converter (VSC) is act as

excitation system and controls real and reactive power of the machine. Boost multi-level neutral point clamped (NPC) VSC is

emerging in industrial applications due to the high dc link voltage utilization and less current THD. Full power converter

redundancy in large rated VSC fed DFIM is challengeable and it is not yet employed in any practical applications such wind power

generation and pumped-hydro power units. Therefore, fault-tolerant control (FTC) of VSC is mandatory for the continuous

operation of unit by the project authorities of the units. This paper presents the fault tolerant and reconfiguration control approach

for a boost NPC converter fed DFIM unit at open circuit faults in all controlled switches/devices. FTC during open-switch faults are

investigated with the help of converter output voltage. Fault detection and isolation is achieved through the rotor currents and dc

link voltage. A 2 MW DFIM is simulated in Matlab/Simulink environment to verify the operation of the proposed fault tolerant

control.