Sensorless control scheme using simple duty feedback technique in DC/DC converters

A sensorless control scheme using simple duty feedback technique in DC/DC converters is presented. The proposed duty feedback control (DFC) has characteristics which show the same operational performance as current mode control by using duty feedback technique without current sensor. Also, it shows faster dynamic response performance than conventional sensorless current mode (SCM) control where input source is perturbed by step change or where DC input source includes the harmonics. In addition, the proposed control scheme displays good noise immunity and has a simple control circuit, as it consists of one feedback loop system and can be applied to all DC/DC converters. The concept and control principles of the proposed control scheme are explained in detail and the validity of the proposed control scheme is verified through several interesting simulated and experimental results.