On the Accuracy of a Time-Domain Identification Method for a DC-DC Buck Converter

This paper describes a discrete time-domain system identification method applied on a DC-DC Buck converter with software control loop. The essence of the method consists in estimating a transfer function of the DC-DC Buck converter that approximates with good accuracy the open loop dynamics of the output of the converter considering as input the PWM control signal. The technique uses an improved approach to enhance the precision of estimation by performing an additional optimization. An analysis of the identification process is made and the influence of several parameters is discussed. The method is verified through experimental results.