Input Current Sensorless Control for a AC-DC Converter with Unknown Load and Source Voltage Amplitude

TL;DR

This paper introduces a novel sensorless control method for AC-DC converters that accurately estimates input current, voltage amplitude, and load conductance despite system uncertainties, enhancing power factor correction performance.

Contribution

A new filtered transformation-based estimator is proposed, enabling global and exponential convergence of input current and load parameters in sensorless AC-DC boost converters.

Findings

Successful estimation of input current, voltage amplitude, and load conductance

Global exponential convergence of estimates demonstrated

Effective integration with dynamic controller for PFC

Abstract

Input current estimation is indispensable in the sensorless control algorithms for the problem of power factor compensation (PFC) of an AC-DC boost converter. The system estimator design is challenged by the bilinear form dynamics and uncertain parameters of the system. In this paper, the system dynamics is immersed to a proper form by a new filtered transformation. Thanks to the proposed transformation, the input current, input voltage amplitude, and load conductance are globally estimated. The exponential convergent of the estimates is established in normal converter operation. An application of the proposed estimator is presented in conjunction with a well-known dynamic controller.