Buck Converter For Applications Research Articles

Efficient maximum power point tracker based on neural network and sliding-mode control for buck converters

Abstract This paper presents detailed design steps of an effective control system aiming to increase the solar energy harvested via photovoltaic power-generation systems. The design of an intelligent maximum power point tracker (MPPT) supported by a robust sliding-mode (SM) controller is discussed in this study. The proposed control scheme is designed to track the MPP and provide a smooth system response by removing the overshoot in the load current during any variation in the connected load. Such a system is suitable for DC–DC buck converter applications. The study begins with modelling the buck converter for a continuous current mode operation. The reference voltage of the tracking system is produced by the proposed neural network (NN) algorithm. The proposed intelligent MPPT integrated with an SM controller is simulated in a MATLAB®/Simulink® platform. The simulation results are analysed to investigate and confirm the satisfaction level of the adopted four-serially connected PV-modules system. The system performance is evaluated at a light intensity of 500 W/m2 and an ambient temperature of 25°C. Applying only the proposed NN algorithm guarantees the MPP tracking response by delivering 100 W at a resistive load of 13 Ω, and 200 W at a load of 6.5 Ω, respectively, with 99.77% system efficiency. However, this simultaneously demonstrates a current spike of ~0.5 A when the load is varied from 50% to 100%. The integrated SM controller demonstrates a robust and smooth response, eliminating the existing current spike.

Active Damping Injection Output Voltage Control with Dynamic Current Cut-Off Frequency for DC/DC Buck Converters

With regard to DC/DC buck converter applications, the objective of this study is to expand the admissible range of the output voltage cut-off frequency while lowering the steady-state current cut-off frequency as possible. This study fortifies the inner loop by incorporating the novel subsystems such as an auto-tuner (for the dynamic current cut-off frequency) and active damping injection invoking the pole-zero cancellation nature with the particular designed feedback gain structure. The outer loop active damping control renders the closed-loop speed transfer function to be a first-order low-pass filter with the cooperation of the specially structured design parameters; in addition, it provides time-varying disturbance attenuation. The experimental results obtained for a 3-kW buck converter validate the feasibility of the proposed technique by showing a 34% performance enhancement (at least) compared with the recent active damping controller.

Effects of electron radiation on commercial power MOSFET with buck converter application

Microelectronic power converters such as buck and boost converter are required to be tolerant to radiations including electron radiation. This paper examines electron radiation effects on the I–V characteristics of VDMOSFET and its corresponding effects in buck converter. Analysis of the electrical characteristics shows that after irradiation the threshold voltage and drain current for all VDMOSFETs degraded more than two orders of magnitude. The impact of this electrical degradation has been investigated in an application of typical buck converter circuit. The buck converter with n-channel switching transistor shows that after irradiation its output voltage increased with the drain current in the n-channel ZVN4424A VDMOSFET, while the buck converter with p-channel switching transistor shows its output voltage decreased with the drain current in the p-channel ZVP4424A VDMOSFET after irradiation.

Power Loss Prediction and Precise Modeling of Magnetic Powder Components in DC–DC Power Converter Application

In power electronics applications, magnetic components are often subjected to nonsinusoidal waveforms, variable frequencies, and dc bias conditions. These operating conditions generate different losses in the core compared to sinusoidal losses provided by manufacturers. In the conception and design stage, lack of precise losses diagnosis has unacceptable effects on sys-tem's efficiency, reliability, and power consumption. Since virtual prototyping is used to predict and improve system's behavior before realization, losses and behavior prediction of components is possible. Circuit simulators and their compatible components models are required. This paper is summarized by proposing nonlinear dynamic model of powdered material magnetic core for use in circuit simulators. It includes the material's nonlinear hysteresis behavior with accurate winding and core modeling. The magnetic component model is implemented in circuit simulation software Simplorer using VHDL–AMS modeling language. Waveforms and losses of a powder core inductor in a buck converter application are simulated and compared to measured ones. The model is validated for different ripple currents, different loads, and a wide frequency range. DC bias is taken into account in both continuous and discontinuous conduction modes.

A pulse skipping modulation with adaptive duty ratio in buck converter application

A pulse skipping modulation with adaptive duty ratio in buck converter application

Design Paradigm for Permanent-Magnet-Inductor-Based Power Converters

Inductors are a significant contributor to mass in many power applications including the dc link in high-power drives and in dc-dc power conversion equipment. Permanent magnet inductors (PMIs) may be used in place of traditional inductors in dc biased applications with significant (40%) mass savings. This paper sets forth a rigorous, systematic, and multifaceted design paradigm for a PMI, using a buck converter application as an example. The algorithm includes electrical, magnetic, and thermal analysis and minimizes overall converter mass and loss. The algorithm is demonstrated in the design and testing of a 4 kW laboratory scale dc-dc converter.

Research on Application of Buck Converter Based on Data-Driven Model-Free Adaptive Controller

State feedback exact linearization method in Buck converters have been widely recognized in the domestic, and it achieved a good control effect, but because the method is based on the accurate modeling, so when the model of controlled object is not accurate enough or circuit parameters in the application are changed, state feedback exact linearization method will be difficult to achieve the ideal control effect. In this paper we use the based on data-driven model-free adaptive controller (MFAC) on Buck Converter Applications for the first time. We analyzed the output characteristic of model-free adaptive control and the state feedback when load changes by simulation. Through the experimental platform of practical, we compared MFAC and the state feedback. Results show that, when the circuit parameter varies in a large range, MFAC has better robustness and resistance mismatch capability, high steady accuracy.

Comparison of Small Signal Characteristics in Current Mode Control Schemes for Point-of-Load Buck Converter Applications

Different current mode controls have been widely adopted in commercial pulsewidth modulation controllers for point-of-load (POL) converter applications. To understand the unique properties of various current mode control schemes, and to study the differences between them, this paper investigates and compares four current mode control schemes (peak-current control, valley-current control, constant on-time control, and constant off-time control) for POL power converters and voltage regulator applications. Performance attributes under investigation include high-bandwidth voltage loop design, adaptability to a converter with a wide input voltage range, adaptive voltage positioning design, and audio susceptibility. The pros and cons of these schemes are identified and explained by the unified small signal equivalent circuit model. In terms of dynamic performance, this study provides a current mode control scheme selection criteria and feedback design guidelines. The theoretical analyses are verified by both simulation and experimental results.

Easy Way to Electronic Converter Designers to Design a Buck Converter Application for Photovoltaic Systems

sophisticated applications require electronic converters to process the electricity from the PV device. These converters may be used to regulate the voltage and current at the load, control the power flow in grid-connected systems, and mainly track the maximum power point (MPP) of the device. Therefore, this paper tries to study an electronic converter in PV systems, namely the Buck converter, and propose an easy way to electronic converter designers to calculate component values needed to realize it.

Boolean-based fractional order SMC for switching systems: application to a DC-DC buck converter

The combination of sliding mode control and fractional order control (FOC) has received a considerable attention in the last years due to the advances and effectiveness of FOC solving robust control problems. This paper collects different methods to apply FOC in sliding mode problems through the use of fractional order surfaces and proposes a direct boolean control (BC) strategy based on this kind of surfaces. The application of BC is novel and takes advantage of avoiding the use of PWM. Simulation results for a DC-DC buck converter application are given to show the goodness of the proposed approach.

Pulse Skipping Modulated Buck Converter - Modeling and Simulation

Modeling and simulation results of a pulse skipping modulated buck converter for applications involving a source with widely varying voltage conditions with loads requiring constant voltage from full load down to no load is presented. The pulses applied to the switch are blocked or released on output voltage crossing a predetermined value. The regulator worked satisfactorily over a wide input voltage range with good transient response but with higher ripple content. Input current spectrum indicates a good EMI performance with crowding of components at audio frequency range for the se-lected switching frequency.

A thin‐film reactor fabricated on an Si‐substrate and its application to dc‐dc converters

AbstractBy means of integrated circuit (IC) process technology, a monolithic thin‐film reactor was fabricated on a silicon substrate with lamination of a thick‐film conductor and a magnetic thin film. In addition to the fundamental characteristics of the reactor, the dynamic characteristics are evaluated when the reactor is used in a dc‐dc converter. For the buck converter application, the output of more than 2 W with the efficiency of more than 70 percent is achieved.