Bifurcation Mechanism and Stabilization of V²C Controlled Buck Converter

Abstract

The V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> C controlled buck converter by constant-frequency pulse-width modulation in continuous conduction mode gives rise to a great variety of instability behaviors, depending on the circuit parameter values. In this paper, the discrete-time model of the regulator is built by taking a current sampling resistor into consideration. The resulting Monodromy matrix is used to investigate the bifurcation phenomenon and stabilization property. The converter shows a series of period-doubling bifurcation phenomena accordingly as the feedback amplification coefficient increases. At the same time, a couple of Floquet multipliers pass through the unit circle along the negative real axis. Therefore, it reveals the mechanism of a series of period-doubling bifurcations happened in the system from the perspective of stability. Based on Floquet theory, a sine voltage compensation method is proposed to stabilize the bifurcation and chaotic behaviors. The simulations and experimental results proved the theoretical analysis.