Abstract
Switched-mode power converters are inherently nonlinear and piecewise smooth systems that may exhibit a series of undesirable operations that can greatly reduce the converter's efficiency and lifetime. This paper presents a nonlinear analysis technique to investigate the influence of system parameters on the stability of interleaved boost converters. In this approach, Monodromy matrix that contains all the comprehensive information of converter parameters and control loop can be employed to fully reveal and understand the inherent nonlinear dynamics of interleaved boost converters, including the interaction effect of switching operation. Thereby not only the boundary conditions but also the relationship between stability margin and the parameters given can be intuitively studied by the eigenvalues of this matrix. Furthermore, by employing the knowledge gained from this analysis, a real-time cycle to cycle variable slope compensation method is proposed to guarantee a satisfactory performance of the converter with an extended range of stable operation. Outcomes show that systems can regain stability by applying the proposed method within a few time periods of switching cycles. The numerical and analytical results validate the theoretical analysis, and experimental results verify the effectiveness of the proposed approach.
Highlights
Due to the benefits of current ripple cancellation, passive components size reduction, and improved dynamic response contributed by interleaving techniques [1,2,3], interleaved switch-mode power converters are widely used in power systems such as electric vehicles [4], photovoltaics power generation [5] and thermoelectric generator systems [6]
The topology of an interleaved boost converter and the diagram of a control strategy are shown in Fig.2, Ki and Kp represent the gains of the PI controller; Kvc and Kil are the gain of signals from the practical sampled output voltage vc and inductor currents iLi (i=1,2) to the controller respectively
In order to control nonlinear behavior and improve the performance of converters, an approach named real-time cycle-by-cycle variable slope compensation (VSC) is proposed which is based on the knowledge of Monodromy matrix
Summary
Due to the benefits of current ripple cancellation, passive components size reduction, and improved dynamic response contributed by interleaving techniques [1,2,3], interleaved switch-mode power converters are widely used in power systems such as electric vehicles [4], photovoltaics power generation [5] and thermoelectric generator systems [6]. It is possible to have a sudden increase in the current ripple and it forces the converter to operate in forbidding current/voltage areas with adding low frequency, high amplitude components These unexpected random-like behaviors potentially lead to a violation of designated operation contours, increased electromagnetic interference (EMI), reduced efficiency and in the worst-case scenario a loss of control with consequent catastrophic failures. All these phenomena cannot be predicted (and avoided) by using conventional linearized model of the converter. Circuit design criteria are always determined by selective ballpark values of components and parameters based on lessons learned from the past rather than applying an appropriate systematic design methodology
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
