Non-average Stability Analysis for a Boost Converter

Abstract

The purpose of this paper is to present a method for analyzing the stability of DC-DC boost converters providing a universal transfer function. This method relies on the application of the Laplace transform without any ad-hoc linear approximation or system linearization. A common methodology for evaluating the stability of DC-DC converters is the average method, which is essentially a linearization. In this paper, the Laplace transform is applied directly, resulting in a universal Z-transform model being used to design controllers and stability analyses as a discrete unifying transfer function. The examples cover both power and low voltage converters. Matlab simulations have been conducted to verify the theoretical findings. In particular, the second example considers a small 5V to 12V boost converter, which was previously examined in a Texas Instruments application note. The transfer functions and the Bode plot are provided.