Buck-boost DC-DC Converter Research Articles

DC-DC Buck Boost Converter For Renewable and Biomedical Application based Real-Time

DC-DC buck boost converter is a conversion circuit using induced frequency inductors, switching.DC-DC converters dynamics was improved by using self calibrated preemptive current control. As, a result Preemptive concurrent control reduces capacitor size by 10x.DC DC buck converter with pulse width modulation.DC-DC buck converter with two step pulse width modulation was utilized for low power application by using delay, control line. Main motive of DC-DC buck converter with pulse width modulations obtains high linearity, high granularity. Conversion efficiency for Light load current was increased in buck converter by clocked hysteresis scheme. Power supplied to comparator was scaled to load easily. Conventional buck converter was integrated with LED to expand smart bulb. Main power from supply was decoupled by Non linear ramp control scheme preventing LED output flickering. Control scheme effectiveness was improved by small signal model. Three major characteristics of Light emitting diodes are improved lifetime, high efficiency, increased reliability, controllability. High brightness LED by multicell three phases was used for its lower cost. Heart beat was identified by using raspberry pi, system on chip with three stages in it namely Heart beat determination, Impedence, cardiography parameters. Accidents was restricted by this method.Overspeeding vehicles was identified was main goal of using complex proportional assessment method. Converting Rice husk into bio fuels was performed by thermo chemical processes. Rice hulk silica was utilized for fluorescent silica particles synthesis.

Grid‐interfaced solar PV powered electric vehicle battery system with novel adaptive digital control algorithm

This study deals with the control of a three-phase grid-tied solar photovoltaic (PV) powered electric vehicle battery (EVB) system. The perturb and observe technique is used to obtain the peak power of a solar PV array. The EVB is connected through a DC-DC buck-boost converter at the DC link of voltage source converter (VSC), which is charged in base load periods and discharged at high load periods. This converter also maintains the DC link voltage to its maximum power point tracking and the EVB capacity is reduced in comparison to a system, where it is directly assimilated at the DC link. An adaptive recursive digital filter is used in an economical and efficient single-stage grid-connected solar PV-EVB system for the evaluation of the fundamental current constituent of non-linear load current, subsequently the grid current is sinusoidal and has unity power factor. The system with recursive filter control is adaptable at solar insolation variation and load change. VSC works as an active power filter under no solar power generation and compensates the load reactive power. The operation of scheme is validated with test results on a prototype developed in steady-state and dynamic conditions.

Bidirectional Twisted Single-Stage Single-Phase Buck-Boost DC-AC Converter

This paper describes a bidirectional twisted single-phase single-stage buck-boost dc-ac converter based on an output unfolding circuit. This solution is derived by the combination of an inverting buck-boost dc-dc converter and an unfolding circuit. The operation principle, component design guidelines, along with the control approach are presented. The zero-crossing distortion problem is discussed and solved by a simple approach. The simulation and experimental results confirm all theoretical statements. Loss distribution and achievable efficiency are analyzed. Finally, the pros and cons of the proposed solution, along with the most promising application field, are analyzed and discussed in the conclusion.

Robust Integral Backstepping Based Nonlinear MPPT Control for a PV System

A photovoltaic system generates energy that depends on the environmental conditions such as temperature, irradiance and the variations in the load connected to it. To adapt to the consistently increasing interest of energy, the photovoltaic (PV) system must operate at maximum power point (MPP), however, it has the issue of low efficiency because of the varying climatic conditions. To increase its efficiency, a maximum power point technique is required to extract maximum power from the PV system. In this paper, a nonlinear fast and efficient maximum power point tracking (MPPT) technique is developed based on the robust integral backstepping (RIB) approach to harvest maximum power from a PV array using non-inverting DC-DC buck-boost converter. The study uses a NeuroFuzzy network to generate the reference voltage for MPPT. Asymptotic stability of the whole system is verified using Lyapunov stability criteria. The MATLAB/Simulink platform is used to test the proposed controller performance under varying meteorological conditions. The simulation results validate that the proposed controller effectively improves the MPPT in terms of tracking speed and efficiency. For further validation of the proposed controller performance, a comparative study is presented with backstepping controller, integral backstepping, robust backstepping and conventional MPPT algorithms (PID and P&O) under rapidly varying environmental conditions.

A Constant Frequency ZVS Control System for the Four-Switch Buck–Boost DC–DC Converter With Reduced Inductor Current

A constant frequency zero-voltage-switching (ZVS) control strategy with a minimum root mean square (rms) value of inductor current is proposed in this letter for the four-switch buck-boost (FSBB) dc-dc converter that is used as a 48 V intermediate bus pre-regulator in distributed power systems. The quadrilateral inductor current modulation is adopted to achieve ZVS operation. The four control time intervals are optimally selected such that the inductor current rms value is minimized, thus reducing the conduction loss. The proposed closed-loop ZVS control scheme can be implemented without sensing the load current, although the rms minimum current algorithm needs the input and output voltages and load current at given a steady-state condition. The control scheme is verified in a 300 W dc-dc prototype of the ZVS FSBB converter. The input voltage and load transition tests are provided to verify the closed-loop characteristics without sensing load current.

Simple control scheme buck-boost DC-DC converter for stand alone PV application system

In this paper a buck-boost dc-dc converter for pv application is proposed, which is mainly composed of a buck – boost converter, PV panel, load and a battery. Existing dc-dc converter can convert the power from the PV panel, but unfortunately the PV panel can only provide power when there is a high intensity of light. In order to provide power supply to the load without any interruption, buck-boost dc-dc converter is introduced. The power intermittency issue of PV panel can be overcome with the aid of a secondary supply which is in this case, the batter. The integration system between the primary and the secondary supply is controlled by a simple proposed control scheme. Battery act as a power in the low voltage side while PV panel is taking over in the high voltage side. Buck-boost converter is operated either is buck or boost mode according to the performance of the PV panel. This paper is presented the simple control scheme to decide the mode suitable for the buck and boost mode. Various conditions are simulated to verify the working operation of the buck-boost converter and to representing solar panel in real life. Simulation and experimental are carried out to verify the system.

A continuous input and output current quadratic buck-boost converter with positive output voltage for photovoltaic applications

This paper proposes a transformerless buck-boost DC-DC converter with positive output voltage. The voltage gain of the proposed buck-boost converter is square of voltage gain of conventional one. Therefore, the proposed converter can operate in a wide range of output voltage. Contrary to the conventional buck-boost converter, the proposed converter benefits from continuous input current, which makes it more suitable for renewable energy applications. Furthermore, the output current of the proposed converter is also continuous, which alleviates the current stress on the output capacitor and brings down the output voltage ripple. Principle operation, steady-state investigation, efficiency analysis and small signal modeling are addressed in detail for continuous conduction mode (CCM). Moreover, the proposed converter is compared to other quadratic buck-boost topologies in terms of different criteria. Finally, the performance of the proposed converter is verified through experimental results.

Stand-alone PV system with MPPT function based on fuzzy logic control for remote building applications

<p align="LEFT"><span>Due to the limitations of reaching the grid utility to remote area, such as rural and/or countryside areas. Stand-alone photovoltaic power systems represent good alternative that it can be adapted for electrical power delivering to these areas. In this paper, a new design of stand-alone solar system suitable for individual building application is presented. This study focuses on proposing a desired solar PV panels matrix arrangement and connection, in addition to presenting an accurate design of Buck-Boost DC-DC converter which controlled by fuzzy logic controller FLC. The controller guarantees the maximum Power Point working conditions and manipulates the fluctuation of the DC link voltage of the matrix due to the weather changing. The main system includes battery bank charger, single phase inverter, and passive power filter. This study addresses the design and performance analysis the DC side of the 7.85 kW PV system. The system performance is evaluated through MATLAB/Simulink results which reflected the promising indications as an effective system for rural individual stand-alone building applications. </span></p>

An Ultra High-Frequency 8-Channel Neurostimulator Circuit With [Formula: see text] Peak Power Efficiency.

In order to recruit neurons in excitable tissue, constant current neural stimulators are commonly used. Recently, ultra high-frequency (UHF) stimulation has been proposed and proven to have the same efficacy as constant-current stimulation. UHF stimulation uses a fundamentally different way of activating the tissue: each stimulation phase is made of a burst of current pulses with adjustable amplitude injected into the tissue at a high (e.g., [Formula: see text]) frequency. This paper presents the design, integrated circuit (IC) implementation, and measurement results of a power efficient multichannel UHF neural stimulator. The core of the neurostimulator is based on our previously proposed architecture of an inductor-based buck-boost dc-dc converter without the external output capacitor. The ultimate goal of this work is to increase the power efficiency of the UHF stimulator for multiple-channel operation, while keeping the number of external components minimal. To this end, a number of novel approaches were employed in the integrated circuit design domain. More specifically, a novel zero-current detection scheme is proposed. It allows to remove the freewheel diode typically used in dc-dc converters to prevent current to flow back from the load to the inductor. Furthermore, a gate-driver circuit is implemented which allows the use of thin gate-oxide transistors as high-voltage switches. By doing so, and exploiting the fundamental working principle of the proposed current-controlled UHF stimulator, the need for a high-voltage supply is eliminated and the stimulator is powered up from a [Formula: see text] input voltage. Both the current detection technique and the gate driving circuit of the current implementation allow to boost the power efficiency up to [Formula: see text] when compared to previous UHF stimulator works. A peak power efficiency of [Formula: see text] is achieved, while 8 independent channels with 16 fully configurable electrodes are used. The circuit is implemented in a [Formula: see text] HV process, and the total chip area is [Formula: see text].

An analog based control scheme applied in stand-alone photovoltaic systems for DC power distribution

The integration of units with primary energy sources, energy storage and loads, is expected to play a promising role in the future of the electricity supply. The distributed energy resources are the basic units for storage and distribution in microgrids. A hybrid unit, which includes a primary energy source and storage simultaneously, is proposed in this work. The unit consists of a DC-DC Buck-Boost converter that tracks the maximum power supplied by a photovoltaic panel, a DC-DC Boost converter that regulates the microgrid DC bus voltage and a DC-DC bidirectional converter which controls the energy flow on the system, charging or discharging a battery bank. The control strategy for these converters should consider the protection of the batteries against voltage transients, as well as the protection of the loads at microgrid bus. Thus, this work proposes a coordinated control strategy for maximizing the power supplied to DC microgrids considering the usage of a photovoltaic energy source and a battery bank under different climate conditions. Simulation and experimental results show that the control strategy tracks the maximum power from the photovoltaic module, charges the batteries when they are discharged, and provides power from the batteries when needed, ensuring the protection of the batteries, autonomous loads and the optimization of energy available for the batteries and loads.

Sensor fault detection and estimation for switched power electronics systems based on sliding mode observer

In this paper, the problem of sensor fault detection and estimation (FDE) for power electronics systems such as DC-DC buck-boost converter is investigated. Firstly, the power electronics system is modeled, and the fault model is given. Then based on the switched Lyapunov function technique, a sliding mode observer (SMO) is designed for the switched error systems, which can guarantee that the error systems are asymptotically stable with a prescribed H∞ performance index. Next, comparing the set threshold with the residual which is produced by the sliding mode observer, the sensor fault detection can be achieved. Meanwhile, based on the method of fault reconfiguration, fault estimation is realized. Finally, in order to show the feasibility of this sensor fault detection and estimation, the simulation of three kinds of sensor faults including open-circuit, gain deviation and noise abnormity is given in this article.

Perturbation and observation as MPPT for highly penetrated grid-integrated PV generator considering symmetrical three-phase fault

This paper presents perturbation and observation (P&O) as maximum power point tracking (MPPT) technique applied on grid-integrated PV generator. The interfacing is carried out via DC-DC buck-boost converter, three-phase sinusoidal DC-AC inverter, LC filter, transformer and two identical transmission lines. Large-signal stability analysis has been carried out considering symmetrical three-phase to ground fault as a case study at the middle of one of the transmission lines. The idea behind introducing the DC-DC converter is to adjust its duty cycle using the P&O algorithm such that to extract the maximum power available in the PV generator at all practical solar irradiance levels. The results show that the highly penetrated grid-integrated PV generator can keep the stability of its operating point despite the large-disturbance considered. It is also concluded that overshoot and settling time of the power system are highly affected by the fault clearing time and solar irradiance level. The higher the solar irradiance level is, the higher the critical clearing time, the larger the overshoot and the lower the settling time tend to be.

Perturbation and observation as MPPT for highly penetrated grid-integrated PV generator considering symmetrical three-phase fault

This paper presents perturbation and observation (P&O) as maximum power point tracking (MPPT) technique applied on grid-integrated PV generator. The interfacing is carried out via DC-DC buck-boost converter, three-phase sinusoidal DC-AC inverter, LC filter, transformer and two identical transmission lines. Large-signal stability analysis has been carried out considering symmetrical three-phase to ground fault as a case study at the middle of one of the transmission lines. The idea behind introducing the DC-DC converter is to adjust its duty cycle using the P&O algorithm such that to extract the maximum power available in the PV generator at all practical solar irradiance levels. The results show that the highly penetrated grid-integrated PV generator can keep the stability of its operating point despite the large-disturbance considered. It is also concluded that overshoot and settling time of the power system are highly affected by the fault clearing time and solar irradiance level. The higher the solar irradiance level is, the higher the critical clearing time, the larger the overshoot and the lower the settling time tend to be.

Исследование работы комбинированного понижающе-повышающего преобразователя для высоковольтной энергопреобразующей аппаратуры

Исследование работы комбинированного понижающе-повышающего преобразователя для высоковольтной энергопреобразующей аппаратуры

High-Efficiency Stacked Power Amplifier IC With 23% Fractional Bandwidth for Average Power Tracking Application

This paper presents a two-stage stacked power amplifier integrated circuit (PAIC) for broadband and high efficiency using a 2-μm InGap/GaAs HBT process with a second-harmonic control circuit and a bias-switching circuit for an average power tracking (APT) application. For APT operation, active bias circuits with a bias switching circuit for the stacked stage were proposed. A simple L-section matching network with a second-harmonic termination circuit was adopted for broad bandwidth and high efficiency. The frequency-independent power and efficiency contours for fundamental and second-harmonic frequency band were extracted at the current-source plane of the transistor. The implemented two-stage PAIC was evaluated using a long-term evolution signal with a peak-to-average power ratio (PAPR) of 7.5 dB and a signal bandwidth of 10 MHz. From 1.55 to 1.95 GHz, the power amplifier exhibited average output power ranging from 27.4 to 28.5 dBm, a power gain of more than 28.6 dB, and a power-added efficiency (PAE) of 36.5 to 41.2% at an ACLR of -30 dBc. At an average output power back-off of 5 dB, the PAE improved to 29.5% with APT using an external buck-boost dc-dc converter, while it was 18.7% without APT.

Power Loss Analysis Model of a Dc-Dc Buck-Boost Converter with an Interfaced Three Phase Inverter for Medium Voltage Application

This paper presents a comprehensive mathematical modelling of a DC to DC Buck-Boost converter. The different power losses associated with the Buck-Boost circuit are also presented. Analysis of the converter power loss is graphically represented at varied duty cycles and load resistance values. A low frequency pulse width modulated inverter is interfaced with the Buck-Boost converter using MATLAB/SIMULINK. For an efficient performance and attenuation of low order harmonics, the low frequency pulse width modulated inverter is substituted with a high frequency pulse width modulated voltage source inverter. A comparison is therefore drawn to show the significant change in the percentage harmonic reduction of the two different frequency modulations. All simulation results are achieved using MATLAB 7.14 version. The simulation results however show that Mosfet switching loss decreases with an increase in the duty cycle whereas Diode and Inductor conduction losses increase with an increase in the duty cycle values.

Artificial Neural Networks Based Maximum Power Point Tracking Photovoltaic System for Remote Park LED Lighting Applications

Due to the difficulty of electricity supplying to the remote locations by the grid, the standalone photovoltaic solar systems are playing a major role instead of the grid connected systems for the mentioned purpose. Remote or rural parks are daily visited locations; for this reason, this paper focuses on guaranteeing the maximum power point tracking(MPPT) conditions during day hours weather fluctuations through the artificial neural network (ANN) technique. ANN is adopted in this study due to its accuracy and fast tracking response by directly estimating the instantaneous values of MPP compared to the conventional techniques. A park lighting of total rated power 1.8 kW based on LED lamps is ,in this study, considered in order to remove the complexity of alternating system requirements such as an inverter, an insulating transformer, and a power filter. MATLAB/Simulink software is adopted in order to evaluate the proposed PV system. The presented study includes PV matrix design based on PV module of MPP power 150 W, an efficient ANN algorithm is working with PI controller in order to have accurate reference voltages and consequently producing the desired PWM drive pulses. A buck-boost DC-DC converter is designed to control the output load power. The collected and analyzed results are promising an effective practical standalone system for park lighting applications.

An improved integrated control modeling of a high-power density interleaved non-inverting buck-boost DC-DC converter

PurposeThis paper aims to propose a novel integrated control method (ICM) for high-power-density non-inverting interleaved buck-boost DC-DC converter. To achieve high power conversion by conventional single phase DC-DC converter, inductor value must be increased. This converter is not suitable for industrial and high-power applications as large inductor value will increase the inductor current ripple. Thus, two-phase non-inverting interleaved buck-boost DC-DC converter is proposed.Design/methodology/approachThe proposed ICM approach is based on the theory of integrated dynamic modeling of continuous conduction mode (CCM), discontinuous conduction mode and synchronizing parallel operation mode. In addition, it involves the output voltage controller with inner current loop (inductor current controller) to make a fair balancing between two stages. To ensure fast transient performance, proposed digital ICM is implemented based on a TMS320F28335 digital signal microprocessor.FindingsThe results verify the effectiveness of the proposed ICM algorithm to achieve high voltage regulating (under 0.01 per cent), very low inductor current ripple (for boost is 1.96 per cent, for buck is 1.1) and fair input current balance between two stages (unbalancing current less than 0.5A).Originality/valueThe proposed new ICM design procedure is developed satisfactorily to ensure fast transient response even under high load variation and the solving R right-half-plane HP zeros of the CCM. In addition, the proposed method can equally divide the input current of stages and stable different parallel operation modes with large input voltage variations.

Low‐power non‐ideal pulse‐width modulated DC–DC buck–boost converter: design, analysis and experimentation

In this study, parasitic elements (non-idealities) effect on a low-power DC-DC buck-boost converter design is analysed and investigation is carried out by both large (i.e. steady-state) and small signal analysis. The large signal analysis of non-ideal buck-boost converter explored the significant information such as nearly accurate duty cycle, maximum allowable duty cycle and maximum possible output voltage. Further, accurate mathematical design formulae are derived of inductor and capacitor for specified inductor current ripple and output voltage ripple (OVR), respectively. Moreover, consequences of different equivalent series resistance of capacitor on OVR is examined. Subsequently, the exact model of buck-boost converter is procured from the small signal analysis, which is almost analogous to practical system. In order to show the impact of non-idealities on controller design, an internal model control PID controller is designed for ideal, semi-non-ideal and complete non-ideal systems based on their respective models, which shows the controller based on non-ideal model provides very close results to practical system. Conclusively, the complete theoretical explorations are justified by simulations and substantiated by experimental results.

Fuzzy Logic Controller Effectiveness Evaluation through Comparative Memberships for Photovoltaic Maximum Power Point Tracking Function

<span style="color: black; font-family: 'Times New Roman',serif; font-size: 9pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; mso-bidi-font-style: italic;">Maximum Power Point Tracking (MPPT) is an important objective needed to gain maximum power from solar photovoltaic panel during the weather condition variation. Many studies and solutions are proposed in literature, most of them focus on the type of algorithm which adopted for MPP tracking through using same driver i.e. DC-DC Boost converter. Among these algorithms, Fuzzy Logic Controller (FLC) demonstrates high quality performance by fast tracking response and robust effectiveness. This paper proposes a FLC by a new harmony of the input and the output variables through comparative study to the controller tracking behavior. To track the MPP, the proposed solution controls the change of duty cycle for PWM gate drive pulses width variation to drive the designed Buck-Boost DC-DC converter. MATLAB/Simulink software is selected to simulate the introduced controller. The simulation results are reflecting the promising indications to adopt the presented proposal as an effective MPPT system for practical applications.</span>