Equalizing Converter Utilization Using a Fuzzy Decision Mechanism based on Input Voltage Perturbation and Time of Usage

Abstract

Abstract — In this paper, fuzzy logic was used to provide the information on the probability of turning ON of four parallel converters using the converter utilization parameter and the input voltage perturbation. Each converter is designed having equal values of inductances and capacitances but with different parasitic resistances and was modelled using MATLAB/Simulink environment. Based on the output probabilities, the appropriate converter/s to turn ON will be turned ON by an enable circuit written in MATLAB code resulting to a well-balanced utilization of all converters. The specified input voltage of each converter is set to be 20 volts with different variances. Since each converter utilizes different supply voltages, the supply voltage is fed to a Gaussian noise realized through a random generator block to provide the variance around 20 volts. The voltage and current errors of each converter were sampled and fed into a discrete controller to regulate its output voltage. Between active converters sharing the load, the average current sharing/ democratic sharing method was used. In this paper, it was found that the fuzzy logic controller can be used to control parallel digital converters to properly balance converter utilization. Simulation results are presented including the static and dynamic loading responses.