Time and frequency domain analysis of fault-tolerant space vector PWM VSI-fed induction motor drive

The use of a new space-vector modulation strategy for a voltage source inverter supplying a fault tolerant induction motor drive is investigated. Such a system uses two distinct space-vector modulation strategies to switch from the healthy to the faulty operation. The proposed modulation strategy for the faulty operation has the same symmetry as in a classical B6 inverter. The purely analytical results both in the time and frequency domain are based on the Laplace transform of the voltage space vectors. There is an excellent agreement between the analytically calculated waveforms and the experimentally determined ones. Therefore, the proposed analytical model becomes a very useful method under unbalanced, as well as balanced, supply conditions.