چكيده به لاتين
In this thesis, a brief explanation in the introduction of the importance of dealing with faults and statistical studies is given. Then, the two-level and multi-level converters and important configurations of these converters will be discussed as well as their advantages and disadvantages. The types of faults that may occur in these converters are introduced. Thereafter, a review of classification in fault diagnosis and fault tolerance is offered. In the following, the various methods used in the previous research in fault detecting and fault tolerant are discussed. Then, the spectrum analysis method, based on the fault of the waveform of each phase voltage is presented as the first method for fault detection and wavelet analysis as a second method. Due to the low computational load, the spectrum analysis method has a high dynamic in fault detecting, and it only needs the voltage waveform to detect faults, which makes it independent of load. The wavelet analysis method, in addition to requiring complex computing, also depends on the load. But will provide useful information to check the faults. Moreover, the technique of phase shift is tested for fault tolerance. The phase shift method, which is introduced for fault tolerance, has many advantages such as lower cost, symmetrical output shape and low voltage drop. In the end, all of these methods are applied to an induction motor in order to confirm the authenticity of these methods and finally, we will conclude with conclusions and some suggestions.