Control Method For DC-DC Converter Research Articles

Research on Modeling and Control Method of DC-DC Converter

Since mankind entered the industrial society, DC-DC converters have been used in many industries. The function of the DC-DC converter is a module that converts DC voltage into DC voltage, which can also be called a power processing system. The main content of this article is to explain the basic principles of Buck converters, and perform modeling and simulation on the MATLAB platform to prove the feasibility of expectations.

태양광 컨버터 시스템의 과도응답 개선을 위한 비선형 적응제어 및 안정성 해석

In photovoltaic(PV) generator systems, DC-DC converters are significantly considered for control system performance in power quality point of view. This paper presents a novel adaptive control method for DC-DC converters applied in PV generator systems. First, we derive a state-space average model of the converter system and then propose a reset control methodology to enhance transient response performance for time-varying PV systems. For estimating parameters of a reset control, a gradient descent optimization is utilized and an adjustment rule of them are derived respectively. An objective of the optimization is that characteristic equation of an augmented system model which is formed with an converter system model and an reset control is to trace a predefined polynomial given as a reference characteristic model. Next, we accomplish stability analysis by means of a well-known Lyapunov theory for nonlinear converter systems including time-varying voltage excitation from a PV generator. Numerical simulation demonstrates reliability of our control methodology and its superiority by comparison to a traditional control strategy.

Robust LQR Control for PWM Converters: An LMI Approach

A consistent framework for robust linear quadratic regulators (LQRs) control of power converters is presented. Systems with conventional LQR controllers present good stability properties and are optimal with respect to a certain performance index. However, LQR control does not assure robust stability when the system is highly uncertain. In this paper, a convex model of converter dynamics is obtained taking into account uncertainty of parameters. In addition, the LQR control for switching converters is reviewed. In order to apply the LQR control in the uncertain converter case, we propose to optimize the performance index by using linear matrix inequalities (LMIs). As a consequence, a new robust control method for dc-dc converters is derived. This LMI-LQR control is compared with classical LQR control when designing a boost regulator. Performance of both cases is discussed for load and line perturbations, working at nominal and non nominal conditions. Finally, the correctness of the proposed approach is verified with experimental prototypes.

Off‐line model predictive control of DCDC converter and its experimental verification

AbstractThis paper presents an optimal control method for DCDC converters. The system is modeled as a mixed logical dynamical system so that the switching property can be considered explicitly. Specifically, the input of the system is confined to a discrete value whereas the output to be controlled is a continuous value. The optimal control law for the system is obtained by means of off‐line model predictive control. The effectiveness of the proposed method is illustrated through numerical simulations and experiments. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Dithering Skip Modulation, Width and Dead Time Controllers in Highly Efficient DC-DC Converters for System-On-Chip Applications

This paper proposes temperature-independent load sensor (LS), optimum width controller (OWC), optimum dead-time controller (ODC), and tri-mode operation to achieve high efficiency over an ultra-wide-load range. Higher power efficiency and wider loading current range require rethinking the control method for DC-DC converters. Therefore, a highly efficient tri-mode DC-DC converter is invented in this paper for system-on-chip (SoC) applications, which is switched to sleeping mode at very light load condition or to high-speed mode at heavy load condition. The efficiency improvement is upgraded by inserting new proposed dithering skip modulation (DSM) between conventional pulse-width modulation (PWM) and pulse-frequency modulation (PFM). In other words, an efficiency-improving DSM operation raises the efficiency drop because of transition from PWM to PFM. Importantly, DSM mode can dynamically skip the number of gate driving pulses, which is inverse proportional to load current. Simplistically and qualitatively stated, the novel load sensor automatically selects optimum modulation method and power MOSFET width to achieve high efficiency over a wide load range. Moreover, optimum power MOSFET turn-on and turn-off delays in synchronous rectifiers and reduced ground bounce can save much switching loss by current-mode dead-time controller. Experimental results show the tri-mode operation can have high efficiency about 90% over a wide load current range from 3 to 500 mA. Owing to the effective mitigation of the switching loss contributed by optimum power MOSFET width and reduction of conduction loss contributed by optimum dead-times, the novel width and dead-time controllers achieve high efficiency about 95% at heavy load condition and maintain the highly efficient performance to very light load current about 0.1 mA.

Optimal Control of DC-DC Converter using Mixed Logical Dynamical System Model

This paper presents an optimal control method of dc-dc converters. The method is based on hybrid dynamical system theory. Specifically, the input of the considered system is confined to discrete value whereas the output to be controlled is continuous value. The system is modeled as a mixed logical dynamical system. Then, the optimal control law is obtained by means of model predictive control. The effectiveness of the proposed approach is illustrated through some numerical simulations.