Control Of Buck-boost Converter Research Articles

A Current Sensorless Control of Buck-Boost Converter for Maximum Power Point Tracking in Photovoltaic Applications

In the present paper, a current sensorless (CSL) method for buck-boost converter control is proposed for maximum power point tracking (MPPT) photovoltaic applications. The proposed control scheme uses the mathematical model of the buck-boost converter to derive a predefined objective function for the MPPT control. The proposed scheme does not require any current sensor and relies only on the input voltage signal, which decreases the implementation cost. The proposed method is successfully implemented using a Matlab/Simulink/Stateflow environment, and its effectiveness is compared over the perturb and observe (P&O) method. An experimental rig, that includes a buck-boost converter, a PV simulator, and a resistive load, is used for the experimental validation. A rapid Arduino prototyping platform is used for the digital implementation, where the SAM3X8E microcontroller of the Arduino DUE board, which integrates an ARM Cortex-M3 MCU, is used as a target hardware for the proposed model-based controller developed under the Stateflow environment. Furthermore, the integrated pulse width modulation (PWM) macrocell is used to generate accurate PWM gate-drive signals for the buck-boost converter. Compared to the P&O, the presented simulation and experimental results show that the proposed method has reduced the computation burden and the sensor cost of implementation by 24.3%, and 27.95%, respectively.

Implementation and study of fuzzy based KY boost converter for electric vehicle charging

Elecetric vehicle batteries require direct current (DC) current for charging; hence the circuit alternating current (AC) is converted to DC by a battery charger. Battery charger mostly consists of a rectifier and DC-DC converter with a controller built in to serve as a protective circuit. A harmonic source load is a type of electric car charger. During the AC-DC change over method, harmonic current is introduced into the power system, affecting power quality. In this study, a charging station consisting of buck boost and a charging station consisting a KY Boost converter were simulated. To maintain output voltage of DC-DC converters constant controller is used, the controller is either PI or fuzzy logic controller. So, four models are developed and simulated which are buck-boost converter controlled by proportional-integral (PI)-controller, KY-boost converter controlled by proportional integral-controller, buck boost converter controller fuzzy logic controller and KY boost-converter controlled by fuzzy logic controller. The total harmonic distortion (THD) of the four models is compared.

Design of a new type of F-COFT controlled BUCK-BOOST converter

As an important method of pulse frequency modulation (PFM), constangt off-time (COFT) is widely used in switching power. However, the switching frequency changes with the input and output voltage, which increases the power consumption of the switching power and is prone to high electromagnetic interference (EMI). Therefore, a new fixed frequency COFT control method (F-COFT) is designed. By designing a charging timing circuit that carries input and output voltage information, the input and output voltage information is fed back to the timing module to realize dynamic adjustment of the constant-off time to ensure the stability of the frequency and eliminate the influence of frequency changes on the circuit. Through LTSPICE simulation, the feasibility of the scheme is verified.

Solar Powered Battery Charging System Using Optimized PI Controller for Buck Boost converter

The basic framework for tuning Genetic Algorithm (GA) is to bring the system to stable condition with proportional Integral controller for DC-DC converter (Buck -Boost Converter) which is applied to PV source. Due to its non-linear characteristics, the performance of the controller needs to be improved in order to improve its efficiency. The gating pulses of the converter uses Pulse Width Modulation (PWM) technique in order to reduce its THD level. The main purpose of PI controller is to bring down the large values of instabilities in the system response and to reduce steady state error which in turns improves the gain and accuracy. Genetic Algorithm (GA) is a search algorithm to solve optimization problems. The controller parameters are optimized to produce reasonable transient response without affecting the stable operation. Output voltage magnitude of DC–DC converter is either greater than or lesser than the input voltage magnitude. Variable DC voltage from PV panel is applied to DC – DC converter to get constant DC output voltage. The modelling of the Proposed system is modelled using MATLAB/SIMULINK and its results are verified.

Power Generation Through VAWT Implementation on Highways & Stabilization the Output Voltage by Controlled Buck-Boost Converter

Power Generation Through VAWT Implementation on Highways & Stabilization the Output Voltage by Controlled Buck-Boost Converter

Modeling and Control of Dish-Stirling Solar Thermal Integrated With PMDC Generator Optimized by Meta-Heuristic Approach

This paper proposes an autonomous microgrid system for the first time with solar thermal dish-Stirling engine coupled with permanent magnet direct current generator and battery energy storage system along with uncontrolled variable loads. Both proportional-integral (PI) and proportional-integral-derivative (PID) controllers are considered separately for the bidirectional charge controller and buck-boost converter controller for the dish-Stirling system. The modern meta-heuristic algorithms including recent ones like particle swarm optimization, mine blast algorithm and grey wolf optimizer (GWO), have been adopted for tuning the gain parameters of the controllers used for the direct current common bus voltage stability and power sharing. The work considers variable insolation level for somehow mimicking the natural solar variation all the day. The simulation of the proposed model is carried out in MATLAB/Simulink and the results are obtained with two types of controllers for comparison. The results demonstrate the superior performance of the PID controllers optimized with GWO algorithm in terms of faster convergence rate, DC voltage profile, and maintenance of SOC of battery and energy efficiency as compared to the other two algorithms. It is also to be noted that the use of a permanent magnet DC generator coupled to the solar dish-Stirling engine improves the electric conversion efficiency and reduces cost effectively as compared to AC generators.

Fuzzy Logic based Hysteresis Controller for Buck-Boost Converter

Fuzzy Logic based Hysteresis Controller for Buck-Boost Converter

A power conversion chain with an internally-set voltage reference and reusing the power receiver coil for wireless bio-implants

In this paper, a power conversion chain (PCC) with an internally-set voltage reference is presented. It is comprised of a power receiver coil, an active rectifier and a novel buck-boost converter. The output voltage of the PCC is set by using the parameters of a new buck-boost converter control unit in order to avoid utilizing an extra voltage reference circuit. Furthermore, the proposed PCC reuses the power receiver coil to facilitate the realization of the buck-boost converter. This way, the efficiency of the proposed PCC gets almost independent of the receiving coil voltage amplitude. In addition, the proposed buck-boost converter significantly reduces the size of the PCC and makes it suitable for wireless power transfer via inductive links in bio-implant applications. It should be noted that employing an active rectifier followed by the proposed buck-boost converter enhances the PCC end-to-end efficiency. The proposed PCC is simulated for the input received signal with a frequency of 10 MHz and an amplitude variation within 3–7 V. The simulation results show that the efficiency variation is less than 2.6% and the achieved maximum efficiency is 80.4% and 63.4% for the proposed converter and PCC, respectively. For further verification of the proposed idea, a proof-of-concept prototype is implemented and experimental results are provided.

Sampled-data modeling and dynamical effect of output-capacitor time-constant for valley voltage-mode controlled buck-boost converter**Project supported by the National Natural Science Foundation of China (Grant Nos. 61371033 and 51407054), the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No. 201442), and the Fundamental Research Funds for the Central Universities of China (Grant No. 2682016CX035).

By analyzing the output voltage ripple of a buck-boost converter with large equivalent series resistance (ESR) of output capacitor, one valley voltage-mode controller for buck-boost converter is proposed. Considering the fact that the increasing and decreasing slopes of the inductor current are assumed to be constant during each switching cycle, an especial sampled-data model of valley voltage-mode controlled buck-boost converter is established. Based on this model, the dynamical effect of an output-capacitor time-constant on the valley voltage-mode controlled buck-boost converter is revealed and analyzed via the bifurcation diagrams, the movements of eigenvalues, the Lyapunov exponent spectra, the boundary equations, and the operating-state regions. It is found that with gradual reduction of output-capacitor time-constant, the buck-boost converter in continuous conduction mode (CCM) shows the evolutive dynamic behavior from period-1 to period-2, period-4, period-8, chaos, and invalid state. The stability boundary and the invalidated boundary are derived theoretically by stability analysis, where the stable state of valley voltage-mode controlled buck-boost converter can enter into an unstable state, and the converter can shift from the operation region to a forbidden region. These results verified by time-domain waveforms and phase portraits of both simulation and experiment indicate that the sampled-data model is correct and the time constant of the output capacitor is a critical factor for valley voltage-mode controlled buck-boost converter, which has a significant effect on the dynamics as well as control stability.

An off-grid stand-alone wave energy supply system with maximum power extraction scheme for green energy utilization in Malaysian Island

AbstractEnergy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. As an island surrounded by sea, power generated by wave energy source will become one of the most promising solutions for the electrification of island areas. But, the unpredictable nature of the wave energy source is the main drawback. This paper presents a novel stand-alone wave energy supply system modeling with maximum power tracking and an energy storage-based power management algorithm in MATLAB/Simulink environment. The main contributions of this research work are eliminating the intermittent power generation nature of wave energy and efficiently extract the maximum wave power. In the proposed stand-alone system, a DC–DC bidirectional buck-boost converter controller is used to maintain the constant dc-link voltage. It also accumulates the surplus wave power in the battery bank and...

Active Disturbance Rejection Control for a Flywheel Energy Storage System

This paper presents the application of the Active Disturbance Rejection Control Technique (ADRCT) to improve the performance of a Flywheel Energy Storage System (FESS). The FESS is designed for the DC MicroGrid (MG) application. It mainly consists of a flywheel with a coaxial BrushLess DC (BLDC) machine, a three-phase full-bridge circuit, and a bidirectional Buck–Boost converter. A model-independent controller based on the ADRCT, which can estimate and compensate model uncertainties and unknown disturbances in real time, is designed for the bidirectional Buck–Boost converter control in the FESS. Simulations and experiments are conducted in both charge and discharge mode to verify the performance of the proposed controller by comparison with a traditional double loop PI controller. Results show that the new controller is more robust and more adaptive. It has a better anti-disturbance capability and a higher dynamic performance than the PI controller. Moreover, to adapt to different applications and operating conditions, the charging process of the FESS is further improved. Strategies on maximum torque control and power limiting control are developed and realized on the experimental platform.

Buck-boost converter controller design using queen-bee assisted GA

We propose a new method of controller design for a buck-boost type dc-dc converter in this paper. An optimisation model for the controller design is developed and solution is sought through a novel optimisation algorithm named as queen-bee assisted genetic algorithm (GA) which combines standard GA with evolution of queen bee in a hive. Computed and measured results suggest that the new algorithm converges to best designs on a limited number of iterations.

Investigation of the Mechanism of Period-doubling Bifurcation in Voltage Mode Controlled Buck-Boost Converter

An investigation of the mechanism of period-doubling bifurcation in a voltage mode controlled buck-boost converter operating in discontinuous conduction mode is conducted from the viewpoint of nonlinear dynamical systems. The discrete iterative model describing the dynamics of the close-loop is derived. Period-doubling bifurcation occurs at certain values of the feedback factor. Results from numerical simulations and experiments are provided to verify the evolution of perioddoubling bifurcation, and the results are consistent with the theoretical analysis. These results show that the buck-boost converters exhibit a wide range of nonlinear behavior, and the system exhibits a typical period-doubling bifurcation route to chaos under particular operating conditions.