A Control Strategy for Harmonic Reduction in a Single Phase High Step up AC-DC Converter Based on Matrix Converter and Cockcroft-Walton Voltage Multiplier with PFC for Low Power Applications

A high-performance transformer-less single-stage high step-up AC-DC matrix converter based on Cockcroft-Walton (CW) voltage multiplier is presented in this paper. This topology deploys a four bidirectional switch matrix converter between the ac source and CW circuit. This configuration offers high quality of line conditions, adjustable output voltage and low output ripple. The matrix converter is operated with two independent frequencies: one of which is associated with Power Factor Correction (PFC) control and the other is used to set the output frequency of the matrix converter. The relationship among the latter frequency, line frequency, and output ripple are also discussed. A 120 V/100-W converter is simulated for the analysis purpose. At full-load, with closed loop control the power factor and the system efficiency are improved and output voltage ripple is reduced. The simulated results presented in this paper demonstrate the high performance of the proposed converter.