Study of Trapezoidal PWM on a 1ϕ AC-AC frequency converter

摘要

Proposed paper describes the implementation of a Trapezoidal Pulse Width Modulation (TPWM) technique to a single phase AC-AC frequency converter. TPWM is used to reduce the total harmonic distortion at the load output of a frequency converter. The converter can be utilized both for step up and step down operation as cyclo-inverter and cyclo-converter respectively. MATLAB/SIMULINK software environment has been used as a tool for simulating results of the AC-AC frequency converter. Number of parameters are varied to observe their effect on the performance on the converter. These include varying the output frequency of the converter, modulation index of the modulating signal, carrier frequency variation and slope variation of the modulating signal etc. %THD for each case was obtained using simulation and were recorded for both cyclo-converter and cyclo-inverter by varying each of the parameters separately and keeping rest parameters constant. The output voltage across the load was found on the higher side of above 90% of the fundamental component.