A current controlled converter with fault tolerant strategy

Abstract

Many of researchers are interested in Pulse Width Modulated (PWM) rectifiers which play an important role in power conversion systems. PWM rectifiers have many ad-vantages like unity power factor and directional power flow. Therefore, they are recently spread to be used for many applications such as electrical vehicles and active filters. Space Vector Modulation (SVM) based Hysteresis Current Control (HCC) is one of current control techniques which has important features that are discussed in this thesis. Therefore, we are interested in studying the current controlled PWM rectifiers with considering the SVM based HCC scheme. PWM rectifier reliability is important to be considered. Therefore, open switch fault detection and tolerant methods are required to improve system reliability. Fault tolerant methods are classified into methods based on software control and methods based on topology control which are presented in this thesis. The objective of this thesis is to analyze the open switch faults of PWM rectifiers in order to find an open-switch fault-tolerant strategy for current controlled (SVM based HCC scheme) PWM rectifiers. This fault-tolerant strategy should maintain the PWM rectifier reliability with less distortion. The suggested strategy is composed of two steps. The faulted zero voltage vector is compensated in the first step, while the faulted active voltage vectors are partially compensated. Then the angle between the reference current and reference voltage vectors is nullified in the second step of the suggested fault-tolerant strategy.