PROJECT TITLE :

Reduced State Observer Based Feedback Control System Design of a Two-Staged AC-DC Converter - 2017

ABSTRACT:

This paper presents a methodology to control a 2-staged ac/dc converter, which could be a cascade combination of a three-part ac-dc boost power issue correction (PFC) rectifier and a section-shifted full-bridge (PSFB) dc/dc converter. This paper explains the issues of instability and losing unity power factor operation, i.e., high reactive power transfer with conventional PI compensator thanks to the sensitive variation of output impedance of the PFC stage at completely different hundreds. In this paper, this instability issue is resolved by the proposed state-feedback management methodology, that shows that there exists a load-insensitive range of controller parameters, providing unity PFC. As an extra benefit of this management, total variety of sensors are reduced by 3 (an input part current, a dc/dc primary current, and an output dc voltage), compared to the conventional PI-based mostly control. This reduction is achieved by introducing two augmented state variables followed by their reduced state observer style. A half dozen-kW laboratory prototype of the integrated 3-phase PFC and PSFB dc/dc is developed and designed to validate the proposed control algorithm. The experimental results show a conversion efficiency of 95.4% at full load, input total harmonic distortion of 4.1%, power issue of zero.998, and output voltage ripple of ±one%.