Stability Analysis of a Boost Converter with an MPPT Controller for Photovoltaic Applications

This paper presents an analysis of the nonlinear dynamics of a current-fed boost converter for PV applications with an MPPT algorithm. First, the model of the converter is derived. Simulation results using this model show that the system can exhibit period doubling bifurcation and subharmonic oscillation when some design parameters are varied. Then, the discrete-time modeling approach and Floquet theory is used to perform a stability analysis of the system periodic orbits, to explain the mechanism of losing their stability and to locate the stability limits in the parameter space. Based on the study, a design of the system free from the undesired subharmonic oscillation can be done. The theoretical results are validated by means of numerical simulations from the circuit-level switched model.