Method of Identifying Buck Converter Load Without Load Current Measurements

This paper proposes a novel method to identify the load without measuring the load current. The variation of load current in the Buck converter affects the feedback performance of the converter, influencing the maintenance of steady output voltage. To ensure the long-period and high-stability operation of the Buck converter. This paper investigates the monitoring of load changes without extra measurement sensors in the original topology. This method mainly utilizes load regulation characteristics in the Buck converter load regulation. When it is necessary to monitor the load condition, the "plug-in" observer will be connected in parallel with the load. Thus the load can be identified by measuring the voltage and bypass current through the external observer. Compared with existing identification methods for converter load, this method avoids measuring the internal parameters and variables inside the converter but only measures the output voltage and bypass current on the output side. The identification values can also be applied to determine the operating status of the converter and further predict the possible fault and failure aroused from the load. In conclusion, SIMETRIX simulations and experiments for three switching converter products under different power levels can validate the proposed method.