Fuzzy controller based space vector pulse width modulation scheme for direct ac conversion system

Abstract

In power electronic applications direct AC/AC conversion plays an important role. This direct AC/AC conversion provides inherent attractive characteristics. There is no need of DC link capacitor. Also four quadrant operation, reduced input distortion and high output power density are feasible in this power conversion. It has many advantages over rectifier fed inverter system. In this research work voltage transformation ratio of the matrix converter is improved. Here space vector pulse width modulation technique is used to improve the quality of the output voltage. Also the space vector pulse width modulation technique is used to operate the matrix converter. In this thesis voltage source inverter and matrix converter performance are described. Single phase matrix converter is synthesized to realize the operation of three phase matrix converter. Performance of single phase matrix converter based on voltage transformation ratio is described. Digital Logic Combination Circuit (DLCC) is proposed for single phase matrix converter. The main objective of this research work is to increase in voltage transformation ratio of the matrix converter using space vector pulse width modulation technique. Open loop analysis of three phase matrix converter is carried out. Three phase matrix converter is simulated for R, RL and induction motor load. Results are compared with voltage source inverter and simulation results are provided. Fuzzy logic based dq axis controller is proposed to get space vector pulse width modulation pulse for three phase matrix converter. Matrix converter switching sequence is selected based on Space Vector Pulse Width Modulation (SVPWM) technique. The analysis of input and output waveforms identifies the constraints that need to be eliminated to ensure successful operation of the matrix converter. This AC/AC conversion system is proposed as an effective replacement for the conventional AC-DCAC system which employs two-step power conversion newline