Current Mode Controlled Boost Converter Research Articles

A Large-Signal Model for a Peak Current Mode Controlled Boost Converter With Constant Power Loads

A large-signal averaged model is obtained to analyze the startup response of a boost converter loaded with a constant power load (CPL) and a peak current mode control (CMC). An analytical methodology is developed for the stability analysis during both startup and steady state. The proposed model corresponds to two operating modes: 1) a reduced-order saturated model during startup mode and 2) an unsaturated full-order model taking place when the system reaches the vicinity of the steady state. The duration of the startup period is also determined using the same model. To verify the validity of the derived large-signal model and the theoretical results derived from it, numerical simulation results from this model are compared with those obtained from a detailed switched model and experimental measurements demonstrating that the model can faithfully predict both the large-signal dynamic response during startup as well as the steady-state regime of the system.

Nonlinear Analysis of Discretization Effects in a Digital Current Mode Controlled Boost Converter

Digital current mode control finds wide spread application in point of load power converters in DC nano-grid because of its technical benefits. However, finite current-loop sampling effects introduce undesirable sub-harmonic oscillations. This paper presents an analytical framework to investigate such nonlinear phenomena in a digitally current mode controlled boost converter. Discrete-time models for multi-sampled current loops and uniform sample with compensating ramp are derived under continuous conduction mode. We show that the discrete-time maps for such systems are discontinuous in nature. While the error voltage using a proportional-integral controller stays within the zero-error-bin (ZEB), the reference current becomes constant and 1-D maps of the inner current-loop can be used for stability analysis. Uniform sampling may lead to chaos, period doubling or stable period-1 behavior depending on slope of the compensating ramp. Multi-sampled current loop imposes several borders in the discrete parameter space and may eventually lead to high periodic behavior. In a counter-based compensating ramp, staircase effects may lead to sub-harmonic oscillation. Such instability eventually brings the error voltage outside the ZEB and 2-D map models have to be used for further investigating the nonlinear phenomena. A boost converter prototype was made. Digital current mode control is realized using an FPGA device. Test results demonstrate close agreement with the analysis.

Controlling Nonlinear Behavior in Current Mode Controlled Boost Converter Based on the Monodromy Matrix

Recently it has been observed that power electronic converters working under current mode control exhibit codimensional-2 bifurcations through the interaction of their slow-scale and fast-scale dynamics. In this paper, the authors further probe this phenomenon with the use of the saltation matrix instead of the Poincaré map. Using this method, the authors are able to study and analyze more exotic bifurcation phenomena that occur in cascade current mode controlled boost converter. Finally, we propose two control strategies that guarantee the stable period-one operation. Numerical and analytical results validate our analysis.

Adaptive Control of Peak Current Mode Controlled Boost Converter Supplied by Fuel Cell

Adaptive control of a peak current mode controlled (PCM) boost converter supplied by a PEM fuel cell is described in this paper. The adaptive controller with reference model and signal adaptation is developed in order to compensate the deviation of the response during the change of the operating point. The procedure for determining the adaptive algorithm's weighting coefficients, based on a combination of the pole-zero placement method and an optimization method is proposed. After applying the proposed procedure, the optimal adaptive algorithm's weighting coefficients can be determined in just a few iterations, without the use of a computer, thus greatly facilitating the application of the algorithm in real systems. Simulation and experimental results show that the dynamic behavior of a highly nonlinear control system with a fuel cell and a PCM boost converter, can fairly accurately be described by the dynamic behavior of the reference model, i.e., a linear system with constant parameters.

Simulation Studies of a Slope Compensated Current Mode Controlled Boost Converter

Simulation Studies of a Slope Compensated Current Mode Controlled Boost Converter

Complex Interaction Between Tori and Onset of Three-Frequency Quasi-Periodicity in a Current Mode Controlled Boost Converter

It is known that power electronic circuits like dc-dc converters are highly nonlinear systems, and that period doubling and Neimark-Sacker bifurcations are common sources of instability in such systems. It has also been shown that these two types of bifurcation may interact, giving rise to interesting dynamical phenomena. In this paper we show that in a current mode controlled dc-dc converter, periodic, quasi-periodic, and saturation behavior can coexist for the same parameter value, and there can be complex interactions between them. Furthermore, abrupt exit to saturation mode can be triggered by a torus-torus collision. Finally, we report the first observation of three-frequency quasi-periodicity in a power electronic system.

Research of Noise Induced Intermittent Chaos in Power Converter

This paper analyzes the working process of current-mode controlled Boost converter and finds that the system will produce the physical phenomenon of intermittency chaos when the converter works in the period windows of chaos zone and external noise reaches certain intensity. It can observe the phenomenon of noise-induced intermittent chaos and it also analyzes the relationship between noise intensity and induced intermittent chaos, the relationship between the noise intensity threshold and circuit parameters in resulting intermittent chaos from the perspective of numerical simulation. The research has an important theoretical and practical significance to nonlinear science and it can provide a reliable theoretical reference for the stable design of switching power converters.

Investigation of the Mechanism of Tangent Bifurcation in Current Mode Controlled Boost Converter

Tangent bifurcation is a special bifurcation in nonlinear dynamic systems. The investigation of the mechanism of the tangent bifurcation in current mode controlled boost converters operating in continuous conduction mode (CCM) is performed. The one-dimensional discrete iterative map of the boost converter is derived. Based on the tangent bifurcation theorem, the conditions of producing the tangent bifurcation in CCM boost converters are deduced mathematically. The mechanism of the tangent bifurcation in CCM boost is exposed from the viewpoint of nonlinear dynamic systems. The tangent bifurcation in the boost converter is verified by numerical simulations such as discrete iterative maps, bifurcation map and Lyapunov exponent. The simulation results are in agreement with the theoretical analysis, thus validating the correctness of the theory.

Bifurcation of Boost converter with two boundaries and its stability control by ramp compensation

Current mode controlled Boost converter has two boundaries in a wide range of circuit parameters. This paper establishes the piecewise smooth iterative map of the converter by utilizing ramp compensation current and derives borderline equations of the orbit state shifting. The reverse bifurcation diagrams and dynamic behavior distribution diagrams with input voltage and compensation slope as parameters are obtained by numerical simulation. The results indicate that with the input voltage reduction, Boost converter enters into robust chaos under continuous conduction mode （CCM） through a border-collision bifurcation on border 1 from stable period-one, and enters into weak chaos and strong intermittency under discontinuous conduction mode （DCM） via a border-collision bifurcation on border 2 By using ramp compensation, the Boost converter can shift from DCM to CCM, and can effectively be controlled to operate at stable period-one region.

Analysis of complex intermittency in Boost converter from a bifurcation control viewpoint

Due to undesirable interference via unintended coupling paths, switching converters may exhibit complex intermittency, which appears as a form of bifurcation undergoing regular operation, subharmonics, and chaos orderly and repeatedly for a long period of time. Such intermittent operation, being an unwanted operating state, should normally be avoided in power converters. This paper expounds the mechanism and conditions for the emergence of intermittency in a common current-mode controlled Boost converter. It is found that interference at frequencies near the switching frequency or its rational multiples may induce intermittent operation. The strengths and frequencies of the interfering signals determine the type and period of intermittency. The problem is analyzed by transforming the time-bifurcation analysis to a conventional parameter-bifurcation analysis. Based on this transformation, intermittency can be investigated from the bifurcation control viewpoint. Furthermore, the critical circuit parameter conditions for the emergence of intermittency can be predicted and compared with those from circuit simulation.