Digital Current Sensorless Control of Current-Driven Full-Bridge DC/DC Converters

摘要

This paper presents a current sensorless technique for current-driven full-bridge dc/dc converters. The proposed technique is able to precisely estimate the transformer current and in turn input/output current of the converter. Since the high-frequency current is estimated, different current-based modulations schemes (e.g., self-sustained oscillating control (SSOC), modulators for synchronous rectifications, etc.) can be implemented using the proposed current sensorless technique. In the proposed technique, the current is estimated using the precise model of dc/dc converters instead of the averaged model. Thus, the accurate current waveform is derived within a switching cycle. The mathematical analysis of the system observability and the practical concerns related to the implementation of the proposed technique are also described in detail. Experimental results on a current-driven dc/dc converter are presented to show the feasibility of the proposed technique and verify its performance.