A Current Sharing Control Method for Parallel DC-DC Buck Converters Based on Exponential Convergence

Abstract

The invention discloses a method for performing current sharing control on a parallel DC-DC type Buck converter on the basis of exponential convergence. The inductive current derivative of each of Buck branches which are connected in parallel and the voltage derivative U<first-order derivative>c of a converter output end are obtained; the tracking error of a voltage is defined, and a dynamic equation is obtained; and the values of duty ratios of control switches in the branches of a current sharing controller based on exponential convergence are obtained according to determined parameters, anda load-time function is obtained according to a response curve of the output voltage and inductive current which vary with the resistance value of the load of the DC-DC type Buck converter. With theexponential convergence-based current sharing controller adopted by the method of the invention used, a faster convergence rate and a better load interference suppression capability can be achieved. The robustness of the system is improved, and the current sharing control speed and accuracy of the parallel DC-DC type Buck converter system are improved.

Description

technical field [0001] The invention relates to the technical field of power electronic control, in particular to a novel current sharing control method for parallel Buck converter circuits based on exponential convergence. Background technique [0002] The parallel DC-DC Buck conversion system has the advantages of large capacity, high efficiency, high reliability and low cost, so it is widely used in high-power load systems. However, in practice, the parameters of each Buck converter are not necessarily the same, so different inductor currents will be generated, which will affect the life of the Buck converter. Therefore, for the parallel DC-DC Buck conversion system, the biggest challenge is the design of the current sharing controller. [0003] Over the years, many control strategies about current sharing have been produced in the control field. Droop control, backstepping current sharing control technology, double closed-loop current sharing control technology, therma...

AI Technical Summary

Problems solved by technology

However, parallel DC-DC Buck converters are nonlinear control objects, and linear control cannot achieve high accuracy and fast convergence.

In recent years, many nonlinear controls, such as chaos control, sliding mode control, control based on exponential convergence have also been applied to this, and great achievements have been made, but they are all used in a single DC-DC type Buck converter

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