Design and implementation of a dual-input single-output photovoltaic converter

In many solar inverters, a dc/dc converter is mainly located between the solar arrays and the inverter. This study presents an enhanced maximum power point tracking (MPPT) algorithm for photovoltaic (PV) systems that drives solar array voltages to track a reference value and decreases fluctuations and oscillations in PV voltage. Different from the previously presented methods, a novel MPPT method is proposed that ensures tracking accuracy by considering output voltage in addition to input voltage and currents. The proposed method detects dI/dV variations, compares the output voltage with the desired reference to shift operation mode and refreshes step size. The digital filtering, enhanced PI, and perturb-and-observe (P&O) tracking features of the proposed MPPT method make it robust to mitigate source fluctuations and sensitivity to partial shading based oscillations. In order to validate the success of the proposed method, a test rig has been installed with dual boost converters. The performance improvements have been verified by both simulation and experimental results that are compared to InCon and P&O MPPT methods. It is also confirmed by experimental results that the proposed MPPT method provides robust control capability in terms of tracking the reference voltage and rejecting the effects of various shading situations on solar arrays

Analysis, Synthesis and Simulation of Compact Two-channel Boost Converter for Portable Equipments Operating with a Battery or Solar Cell

AbstractThis paper is intended to help engineers and designers of high power industrial application such as engineers of power systems as well as control engineers and designers of very low power industrial applications such as designers of computer motherboards and other microcomputer circuits supplied from alternative energy sources or battery via boost converters.Alternative energy source systems such as solar-cells or photovoltaic systems (PV) are progressively becoming more popular. In these applications, it is often required to convert the generated low DC voltage to a higher variable voltage prior to converting it into an AC to be compatible with the electric grid and common appliances. Usually a boost converter is used to step up the d.c. voltage generated at the outputs of such systems [1]. The basic configuration of boost converters usually used for this purpose suffers from some drawbacks just like high ripple in their output currents and voltages which increases the losses of the system and makes their control complicated and their response to the variation in the input voltage and load parameters unstable.To eliminate these drawbacks, this paper introduces a two-channel boost regulator with uncoupled smoothing reactors. Detailed analysis, design, control strategy and simulation have been proposed in this paper to investigate the advantages of using the two-channel connection with uncoupled smoothing reactors.It has been proved throughout this paper that two-channel configuration of boost converter helps increasing the output power of the converter, filtering out the harmonic content from its output and input, making their control easier and more efficient, increasing the operating frequency of the converter and thus decreasing the size of the components and filters used in the circuit.Moreover, the paper deals with voltage control strategy that usually used for such systems thus to regulate the boost converter to obtain a robust output current and voltage. Simulation results show that voltage mode control technique provides good current and voltage regulation of boost converters and is more feasible for the chopper up conversion technique of these converters

Power Quality Enhancement in Hybrid Photovoltaic-Battery System based on three–Level Inverter associated with DC bus Voltage Control

This modest paper presents a study on the energy quality produced by a hybrid system consisting of a Photovoltaic (PV) power source connected to a battery. A three-level inverter was used in the system studied for the purpose of improving the quality of energy injected into the grid and decreasing the Total Harmonic Distortion (THD). A Maximum Power Point Tracking (MPPT) algorithm based on a Fuzzy Logic Controller (FLC) is used for the purpose of ensuring optimal production of photovoltaic energy. In addition, another FLC controller is used to ensure DC bus stabilization. The considered system was implemented in the Matlab /SimPowerSystems environment. The results show the effectiveness of the proposed inverter at three levels in improving the quality of energy injected from the system into the grid.Peer reviewedFinal Published versio

Design and Implementation of Takagi-Sugeno Fuzzy Tracking Control for a DC-DC Buck Converter

This paper presents the design and implementation of a Takagi-Sugeno (T-S) fuzzy controller for a DC-DC buck converter using Arduino board. The proposed fuzzy controller is able to pilot the states of the buck converter to track a reference model. The T-S fuzzy model is employed, firstly, to represent exactly the dynamics of the nonlinear buck converter system, and then the considered controller is designed on the basis of a concept called Virtual Desired Variables (VDVs). In this case, a two-stage design procedure is developed: i) determine the reference model according to the desired output voltage, ii) determine the fuzzy controller gains by solving a set of Linear Matrix Inequalities (LMIs). A digital implementation of the proposed T-S fuzzy controller is carried out using the ATmega328P-based Microcontroller of the Arduino Uno board. Simulations and experimental results demonstrate the validity and effectiveness of the proposed control scheme

Robust Control of a Multi-phase Interleaved Boost Converter for Photovoltaic Application using µ-Synthesis Approach

The high demand of energy efficiency has led to the development power converter topologies and control system designs within the field of power electronics. Recent advances of interleaved boost converters have showed improved features between the power conversion topologies in several aspects, including power quality, efficiency, sustainability and reliability. Interleaved boost converter with multi-phase technique for PV system is an attractive area for distributed power generation. During load variation or power supply changes due to the weather changes the output voltage requires a robust control to maintain stable and perform robustness. Connecting converters in series and parallel have the advantages of modularity, scalability, reliability, distributed location of capacitors which make it favorable in industrial applications. In this dissertation, a design of µ-synthesis controller is proposed to address the design specification of multi-phase interleaved boost converter at several power applications. This thesis contributes to the ongoing research on the IBC topology by proposing the modeling, applications uses and control techniques to the stability challenges. The research proposes a new strategy of robust control applied to a non-isolated DC/DC interleaved boost converter with a high step voltage ratio as multi-phase, multi-stage which is favorable for PV applications. The proposed controller is designed based on µ-synthesis technique to approach a high regulated output voltage, better efficiency, gain a fast regulation response against disturbance and load variation with a better dynamic performance and achieve robustness. The controller has been simulated using MATLAB/Simulink software and validated through experimental results which show the effectiveness and the robustness

Reset control for DC-DC converters: an experimental application

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Power converters in grid connected systems are required to have fast response to ensure the stability of the system. The standard PI controllers used in most power converters are capable of fast response but with significant overshoot. In this paper a hybrid control technique for power converter using a reset PI + CI controller is proposed. The PI + CI controller can overcome the limitation of its linear counterpart (PI) and ensure a fast flat response for power converter. The design, stability and cost of feedback analysis for a DC-DC boost converter employing a PI + CI controller is explored in this work. The simulation and experimental results which confirm the fast, flat response will be presented and discussed.Peer ReviewedPostprint (published version

Power Quality Improvement and Low Voltage Ride through Capability in Hybrid Wind-PV Farms Grid-Connected Using Dynamic Voltage Restorer

© 2018 IEEE. Translations and content mining are permitted for academic research only. Personal use is also permitted, but republication/redistribution requires IEEE permission.This paper proposes the application of a dynamic voltage restorer (DVR) to enhance the power quality and improve the low voltage ride through (LVRT) capability of a three-phase medium-voltage network connected to a hybrid distribution generation system. In this system, the photovoltaic (PV) plant and the wind turbine generator (WTG) are connected to the same point of common coupling (PCC) with a sensitive load. The WTG consists of a DFIG generator connected to the network via a step-up transformer. The PV system is connected to the PCC via a two-stage energy conversion (dc-dc converter and dc-ac inverter). This topology allows, first, the extraction of maximum power based on the incremental inductance technique. Second, it allows the connection of the PV system to the public grid through a step-up transformer. In addition, the DVR based on fuzzy logic controller is connected to the same PCC. Different fault condition scenarios are tested for improving the efficiency and the quality of the power supply and compliance with the requirements of the LVRT grid code. The results of the LVRT capability, voltage stability, active power, reactive power, injected current, and dc link voltage, speed of turbine, and power factor at the PCC are presented with and without the contribution of the DVR system.Peer reviewe