Voltage oriented and model predictive control of three-phase vienna rectifier.

Abstract

Generally, the conversion from AC to DC uses conventional uncontrollable or controllable diodes rectifier in both single phase and three phases. The main drawbacks of these rectifiers are injecting a huge amount of distortion in the AC-side line currents, low power factor and high ripple factor in the output DC- side. Recently, new types of controllable AC to DC converters such as PWM rectifier and Vienna rectifier which improve the quality of AC- line current with a low harmonics distortion, high power factor that is almost unity and a straight output DC- current which reduce ripple factor. This thesis is interested in comparison study between PWM rectifier and Vienna rectifier. Both structures and principle of work of these rectifiers are presented and what are factors that control them. It also covers the SVM (space vector modulation) and how this technique is different from a rectifier to another. Finally, the performance of PWM and Vienna rectifiers are evaluated under several control strategies such voltage oriented control (VOC) and model predictive control- finite control set (MPC-FCS) that reduce the complexity of previous control strategy. The performances are tested under different conditions balanced, unbalanced and distorted network. All covered techniques are simulated using MATLAB/Simulink software.