Study On The Modeling And Nonlinear Control Of DC/DC Converter On Vehicle

DC/DC converter is a kind of time-varying nonlinear system, stability analysis and the main controller design method is based on the state space averaging method to establish small-signal model to analysis. For the vehicle DC/DC converter is relatively poor working conditions, the input voltage and load disturbance are associated with large-scale, and small-signal model based control law could not guarantee vehicle DC/DC converter is reliable. It's necessary to research more precise nonlinear model for DC/DC converters and more efficient control method for lager-signal disterbance. Thus provide an inportant theoretical basis for the design high performance controller of DC/DC converter.First, consider the DC/DC converter in vehicle power is buck converter, this paper introduces and analyzes the circuit topology, working principles and modeling methods of Buck DC/DC converter and full-bridge converter.Secondly, this paper use the state space equation of Buck Converter, consider of the input voltage and load resistance of large-signal disturbance, get a new switching control strategy for the application of Lyapunov direct method to analyze their closed-loop control model. And simulated the control strategy of Buck converter in PLECS. The results show that the control strategy can effectively inhibit the large-signal disturbance, meet the large-signal stability of perturbed systems.Finally, based on the Buck circuit large signal stability analysis, this paper apply Lyapunov direct method to full-bridge circuit modeling analysis, and get a full bridge switching converter control strategy. Then, simulated the control strategy in PLECS. The results show that the control strategy make full-bridge circuit in the large signal perturbation stability.