Showing papers on "Switched capacitor published in 2021"

A Step-Up Multilevel Inverter Topology Using Novel Switched Capacitor Converters With Reduced Components

Abstract: In this article, basic cell (BC) of a novel swi-tched capacitor converter (SCC) has been proposed first. After that, the generalized structure of proposed SCC is developed. The developed SCC requires reduced number of switches, drivers, diodes, capacitors, and lower number of conducting switches in current flow paths and capacitor charging paths as compared to the other recently developed SCCs. A switched capacitor multilevel inverter (SCMLI) utilizing two numbers of generalized SCCs is developed next. Further, cascaded extension of proposed SCMLI is realized and analyzed for symmetric and asymmetric dc source configurations. A detail analysis of optimum selection of capacitance for switched capacitors of 13-level SCMLI is presented. An extensive comparison study shows that the proposed SCMLI requires lower number of components as compared to other SCMLIs. Further, the proposed structure has minimum cost function per level per boosting factor as compared to the other SCMLIs. Extensive experimental results considering fundamental switching frequency scheme are presented to validate the merits and effectiveness of the proposed structure.

Single-Phase Step-Up Switched-Capacitor-Based Multilevel Inverter Topology With SHEPWM

Abstract: Multilevel inverter (MLI) topologies play a crucial role in the dc–ac power conversion due to their high-quality performance and efficiency. This article aims to propose a new switched-capacitor-based boost multilevel inverter topology (SCMLI). The proposed topology consists of nine power semiconductor switches with one dc voltage source and two capacitors, capable of generating a nine-level output voltage waveform with twice voltage gain. With the addition of two switches, the proposed topology can be used for higher voltage-gain applications. Other features of the proposed topology include the self-voltage balancing of the capacitors, parallel operation of the capacitors, lower voltage stress across the switches, along with the inherent polarity changing capability. To obtain the high-quality output waveform, a selective harmonic elimination pulsewidth modulation technique is applied. In this technique, the detrimental low-order harmonics can easily be regulated and eliminated from the output voltage of MLI. The proposed topology is compared with the recently introduced SCMLI topologies considering various parameters to set the benchmark of the proposed topology. The performance of the proposed MLI is investigated through various experimental results using a laboratory prototype setup.

Six-Switch Step-Up Common-Grounded Five-Level Inverter With Switched-Capacitor Cell for Transformerless Grid-Tied PV Applications

Abstract: Photovoltaic string inverters with transformerless grid-connected architecture are the most commonly used solar converters owing to their appliance-friendly and cost-effective benefits. A novel circuit configuration for these converters is presented in this article, which seeks to address the shortcomings of most of the conventional topologies such as the problem of leakage current, voltage ratio transformations, and power quality. The proposed structure is based on the series–parallel switching conversion of the switched-capacitor (SC) cell and is comprised of only six unidirectional power switches with a common-grounded (CG) feature. Through the use of the SC cell and the CG connection of active and passive used elements, not only is the number of output voltage level enhanced by up to five but also a two times voltage boosting feature with a single-stage operation as well as elimination of the leakage current is acquired. Herein, to inject a tightly controlled current into the grid, a peak current controller approach has been used which can handle both the active and reactive power supports modes. Theoretical analysis, design guidelines, comparative study, and some experimental results are also given to corroborate the feasibility and accurate performance of the proposed topology.

A Novel Generalized Common-Ground Switched-Capacitor Multilevel Inverter Suitable for Transformerless Grid-Connected Applications

Abstract: Recent research on common-ground switched-capacitor transformerless (CGSC-TL) inverters shows some intriguing features, such as integrated voltage boosting ability, possible multilevel output voltage generation, and nullification of the leakage current issue. However, the number of output voltage levels and also the overall voltage boosting ratio of most of the existing CGSC-TL inverters are limited to five and two, respectively. This article presents a generalized circuit configuration of such converters capable of higher voltage gain and output voltage levels generation. A basic five-level (5L) CGSC-TL inverter is first proposed using eight power switches and two self-balanced dc-link capacitors. A generalized extension of the circuit for any output voltage levels and voltage gain is then presented while keeping all the traits of the proposed basic 5L-CGSC-TL inverter. The circuit descriptions, control strategy, design guidelines, comparative study, and the relevant simulation and experimental results for the proposed 5L-CGSC-TL inverters and its seven-level derived topology are presented to validate the effectiveness and feasibility of this proposal.

A Novel Modified Switched Inductor Boost Converter With Reduced Switch Voltage Stress

Abstract: Recently, switched inductor (SI) and switched capacitor techniques in dc–dc converter are recommended to achieve high voltage by using the principle of parallel charging and series discharging of reactive elements. It is noteworthy that four diodes, one high-voltage rating switch, and two inductors are required to design classical SI boost converter (SIBC). Moreover, in classical SIBC, the switch voltage stress is equal to the output voltage. In this article, modified SIBC (mSIBC) is proposed with reduced voltage stress across active switches. The proposed mSIBC configuration in this article is transformerless and simply derived by replacing the one diode of the classical SI structure with an active switch. As a result, mSIBC required low-voltage rating active switches, since the total output voltage is shared into two active switches. Moreover, the proposed mSIBC is low in cost, provides higher efficiency, and requires the same number of components compared with the classical SIBC. The continuous conduction mode and discontinuous conduction mode analysis, the effect of nonidealities on voltage gain, design methodology, and comparison are presented in detail. The operation and performance of the designed 500-W mSIBC are experimentally validated under different perturbations.

Self-Balanced 13-Level Inverter Based on Switched Capacitor and Hybrid PWM Algorithm

Abstract: A 13-level inverter based on switched-capaci-tor technique is proposed in this article. It consists of ten transistors, four diodes, and four capacitors with self-balanced voltages. The ten transistors form two H-bridges and one half-bridge resulting in simple structure and easy design of gate drivers. With a hybrid of level-shifted and phase-shifted pulsewidth modulation algorithm, voltage ripples of capacitors and low harmonic components of output voltage are suppressed simultaneously. Compared with the existing solutions, the proposed 13-level inverter has a simpler structure and the lower cost per level. Experimental results demonstrate that the proposed inverter has the advantages of high boosting factor, self-balanced capacitor voltages, low harmonics, and high efficiency, and the maximum efficiency is up to 97.2%.

Improved Hybrid Switched Inductor/Switched Capacitor DC–DC Converters

Abstract: High voltage gain dc–dc converters are widely used in various applications like low-voltage sustainable sources. In traditional boost converters, the voltage gain is limited by high voltage stress, high current ripple, and low efficiency due to employing a high duty cycle ratio. In this article, we propose converters that are a combination of four substructures, namely active switched inductor, passive switched inductor, switched capacitor cell, as well as an auxiliary switch with nonisolated configuration. The proposed structures have high voltage gain compared to the conventional either switched inductor-based or switched capacitor-based ones in addition to a low duty cycle ratio. By adding an auxiliary switch, the efficiency is improved, particularly for high voltage gains. The principle of operation and steady-state analysis are discussed in detail. Also, simulation results from PSCAD/EMTDC software are validated by a prototype built for experimental examination. The results demonstrated that the voltage gain and efficiency could be improved by utilizing the auxiliary switch.

A 13-Level Switched-Capacitor-Based Boosting Inverter

Abstract: A new boosting multilevel inverter with switched-capacitors is presented in this brief. By employing 13 switches, two diodes, and three capacitors, a 13-level voltage waveform is synthesized. The capacitor voltages are self-balanced as they are connected in parallel with the input voltage source for several instances in every fundamental cycle. A simple logic gate based pulse-width modulation scheme ensuring power balance among the capacitors is presented. Experimental results obtained from a laboratory prototype are presented for validating the operation and ability of the proposed inverter to boost the input by a factor of six. Finally, a detailed comparison with existing topologies proves the cost-effectiveness, a simpler structure requiring lesser space and footprint area of the proposed topology.

A 13-level Switched-Capacitor Multilevel Inverter with single DC source

Abstract: In this article, a novel 13-level inverter Single source, Switched-Capacitor Multi-Level Inverter (SSC-MLI), is proposed. This topology is suitable for renewable energy applications using less input voltage source magnitude. This structure is capable of boosting the input voltage six times with the help of switched capacitors. The capacitors are automatically balanced without any control algorithms, complex circuits, or closed-loop controllers. The advantages of the proposed structure are high power density and high efficiency by use of only switches. Since, there is no diodes there is no forward conduction loss, and no reverse recovery delay. The maximum blocking voltage across individual switch is three times the input voltage. The functionality of the SSC-MLI is described in detail. The capacitance calculation and optimum value of capacitors are discussed. A suitable comparison is presented for the proposed structure with the existing literature to check the inverter performance. The power loss for exiting a 13-level inverter is presented. The simulation is carried out for both pure resistive and inductive load. Later, the experimental results are presented for variation in frequency, dynamic change in load, variation in modulation index, and step-change in input voltage to validate the proposed topology performance and feasibility.

A Single-Source Nine-Level Boost Inverter with A Low Switch Count

Abstract: Switched-capacitor-based multilevel inverters for boost-type dc-ac power conversions usually exhibit a trade-off between the switch count and switch-voltage rating, i.e., a reduction of one necessitating an increase of the other. Such a dilemma is well addressed in this paper by proposing a novel single-phase nine-level inverter based on a switched-capacitor network with a single switch. The proposed inverter then reduces the number of switches while generating a boosted dc-link voltage. A unique six-switch full-bridge cooperating with a low-frequency half-bridge further steps-up the output voltage with a quadruple gain. The voltage stresses on the power devices are, however, maintained low even under the boosted high output voltage, as all the switches/diodes can be clamped to any of the low-voltage capacitors. Consequently, low-voltage power devices can be utilized, reducing the overall power loss. Detailed theoretical analysis, calculations, and design considerations of the proposed inverter are provided. Comparisons with the prior-art inverters illustrate its advantages. Simulations and experimental tests on a 1-kVA inverter prototype verify the above-claimed benefits.

A High Step-Up Switched-Capacitor 13-Level Inverter With Reduced Number of Switches

Abstract: This letter presents a new single-phase 13-level switched-capacitor inverter with a reduced number of switches and a voltage boost gain of 6. The proposed topology with a single dc source can achieve 13-level output, sextuple boost, and self-voltage balance of capacitors using only 14 switches. The proposed inverter does not use a back-end H-bridge with four switches that must withstand the peak load voltage, and the voltage stress of all switches does not exceed half of the peak load voltage. The operation principle including the self-voltage balance of capacitors is described in detail. An analysis of the proposed inverter in comparison to recent topologies with a single-input dc source is performed mainly in terms of the number of switches and cost function. Simulation and experimental results verify the feasibility of the proposed topology.

A Double-Side Self-Tuning LCC /S System Using a Variable Switched Capacitor Based on Parameter Recognition

Abstract: In order to allow a wireless power transfer system to operate in a large-scale space where coupling coefficient has a significant variation due to different air gaps and displacements, a double-side self-tuning LCC /S system using a variable switched capacitor based on parameter recognition is proposed in this article. The main innovation is that the parameter recognition method is able to recognize both mutual inductance and double-side self-inductance with only rms value of sampling signal, phase information and auxiliary circuit being needless. Besides, based on the result of parameter recognition, the double-side use of variable switched capacitors and corresponding control strategy allow the proposed system to operate in a large-scale coupling space and help to improve system efficiency. Experiment results show parameters recognizing error less than 5%. A contrastive simulation verifies that variable switched capacitor can be equivalent to discrete capacitor with the same branch current in the proposed system. System feasibility is testified by a 700-W prototype and the effectiveness of the proposed system is demonstrated by a contrastive experiment with and without pulsewidth modulation (PWM) tuning, efficiency from dc to dc will increase about 3% with PWM tuning.

Review of High-Frequency High-Voltage-Conversion-Ratio DC–DC Converters

Abstract: The development of high-frequency power converters is continuously improving their power density, efficiency and fast dynamic response. Among them, high-voltage-conversion-ratio (HVCR) dc–dc converters are widely used in high gain, i.e., step-up/-down or bidirectional applications, such as power supply for data center, dc micro-grids, electrical vehicle charging systems, etc. In this article, the current main high-frequency HVCR dc–dc converters are classified into inductive-based and capacitive-based approaches, which can then be described further by four kinds in detail, namely transformer-based, coupled-inductor-based, and switched-capacitor-based, as well as combination of coupled inductor and switched capacitor. A comprehensive analysis and comparison is given, which can provide guidance for proper topology selection and further topology optimization.

Quadruple Boost Multilevel Inverter (QB-MLI) Topology With Reduced Switch Count

Abstract: Multilevel inverter concepts (MLIs) with switched capacitor (SC) are emerging due to their scope in sustainable energy systems as well as high-voltage applications. In the SC technique, required voltage levels can be achieved with the lesser number of dc sources in combination with the capacitor voltage. In this perspective, the design of high-gain MLI with reduced sources as well as switch count is a challenging task. This letter proposes a single-source-driven quadruple boost multilevel inverter topology (QB-MLI) with lesser order of resources over the other SC MLIs. The proposed QB-MLI is capable to produce nine levels of voltage in output by effectively balancing the two capacitor's voltage with the associated control logic. The different SC MLIs are compared to verify the pros and cons with respect to the contribution of the proposed QB-MLI topology. Detailed experimental results at various test conditions of a laboratory set-up have been presented to validate the performance of the proposed QB-MLI.

DC-Link and Switched Capacitor Control for Varying Coupling Conditions in Inductive Power Transfer System for Unmanned Aerial Vehicles

Abstract: The use of wireless power transfer technology in unmanned aerial vehicle (UAV) systems is rapidly improving in different application areas. The main limitations of electric-powered UAVs are their charging range and stability in dynamic conditions. To solve these, this article proposes a hybrid control method based on dc-link and switched capacitor control with a fixed operating frequency. The dc-link voltage is regulated by the boost power factor correction converter to smoothen the output voltage, and the switched capacitor is used to dynamically compensate for self-inductance variations under dynamic coupling conditions. The output voltage stabilization and near-unity power factor of the input impedance can be achieved by applying the hybrid control method. Therefore, efficiency improvement can be achieved. Furthermore, the proposed control method can also be applied to systems with large coupling variations. To verify the proposed control method, a 500-W prototype was set up in the laboratory, and the experimental results proved that the control method could ensure a stable output voltage with horizontal and vertical offsets of 200 and 62 mm. respectively. Additionally, the results show that the maximum efficiency of the proposed control method is 91.9%, demonstrating that the proposed method effectively improves the efficiency.

Design of Parallel Resonant Switched-Capacitor Equalizer for Series-Connected Battery Strings

Abstract: The traditional pure switched-capacitor equalizer suffers from a large inrush current and low balance speed. An automatic parallel resonant switched-capacitor equalizer (PReSCE) for series-connected battery strings is proposed, which utilizes resonant switched-capacitor to eliminate the inrush current. The parallel ReSC converters not only minimizes output impedance at the low switching frequency, but delivers the excess energy to the low-voltage battery directly from the high-voltage battery in one cycle. Both of the two functions increase the balance speed. All of the switches are controlled by a pair of complementary pulsewidth modulation signals at a fixed operational frequency. Both simulation and experiment are used to verify the theoretical analysis and system feasibility of the proposed circuit. The results show that the PReSCE circuit eliminates the inrush current and increases the balance speed three times than the parallel pure switched-capacitor equalizer.

Circuit Configuration and Modulation of a Seven-Level Switched-Capacitor Inverter

Abstract: In this article, a step-up seven-level inverter supplied by a single dc source suitable for renewable energy application is presented. Forming the desired output is realized by charging capacitors and synthesizing them based on a switched-capacitor concept. This structure is praised for the ability of sensorless voltage balancing of the capacitors, reducing control complexity to produce a bipolar staircase waveform. It also benefits from regenerative performance, avoiding unwanted capacitors overvoltage. A phase disposition pulsewidth modulation (PD-PWM) technique is utilized to control the circuit operation. Furthermore, a comparison with other recent topologies reveals that losses, number of semiconductor devices, and gate driver circuits are reduced. Theoretical analysis is verified through a laboratory prototype implementation. Experimental results under various types of loads approve the performance of the proposed inverter and validity of the design. Finally, maximum experimental efficiency of 94.3% (115 V, 250 W load) was reached.

A New Family of Step-Up Hybrid Switched-Capacitor Integrated Multilevel Inverter Topologies With Dual Input Voltage Sources

Abstract: In the low voltage based renewable systems like PV and Fuel cell applications, the step-up of the output voltage to drive the loads is essential. For this, the integration of switched-capacitor (SC) units with the dc-ac converters will have the potential advantages like improved efficiency, optimal switching devices, small size of passive elements (L and C) as compared with traditional two-stage conversion system (dc/dc converter and dc/ac converter). This paper focuses on a new family of step-up multilevel inverter topologies with switched capacitor integration with dual input voltage sources. With the flexibility of 2 dc sources and switching capacitor circuits, four different topologies have been suggested in this paper with features of high voltage gain, reduced component count, reduced voltage stress and self-voltage balancing of the capacitor while achieving a higher number of levels. A detailed analysis of proposed multilevel inverters has been analyzed with the symmetrical and asymmetrical mode of operations and the associated gain, the number of levels, and other performance indices are presented. An in-depth study of all the topologies has been accomplished in this paper with several comparative studies in terms of components count, voltage gain and cost. The effectiveness and practicability of the suggested topology with 13 level output voltage has been explained by the experimental results obtained from a scale down prototype.

A Novel High Step-Up Switched-Capacitor Multilevel Inverter With Self-Voltage Balancing

Abstract: This article presents a novel high step-up multilevel inverter (MLI) with a single dc source based on switched-capacitor modules in which it is suitable for the renewable energy applications with low-voltage dc source. The proposed topology has the ability of the voltage self-balancing for the capacitors without any external or closed-loop circuits. Another merit of the proposed structure is the production of bipolar staircase waveform without any end-side full-bridge in which it reduces the voltage stress on components remarkably. The circuit topology and its operation principle, capacitance calculations and comparison of the proposed circuit with other well-known single-source MLIs are discussed in detail. Finally, a 21-level prototype of the proposed inverter with 32 V input voltage and high gain 10 by using four modules was evaluated by both simulation and experimental tests.

Switched-Capacitor-Based Multilevel Inverter for Grid-Connected Photovoltaic Application

Abstract: In order to approach a voltage of high magnitude in photovoltaic (PV) application, several PV modules are connected in series to form a PV string, then the voltage of PV string is converted to an ac voltage through an H-bridge inverter. This system causes harmful harmonics, brings about leakage current, and increases the voltage stress of the components. To tackle the issue, this article proposes a new switched-capacitor-based multilevel inverter topology that uses series-connected dc sources as the input dc source and generates a staircase ac voltage of high quality and mitigates the leakage current. The proposed topology can be constructed as a three-phase inverter as well, in the three-phase configuration all the phases are connected to only one series-connected PV module or dc sources. Simulation and experimental results are provided to validate the proposed topology.

Hybrid High Voltage Gain Transformerless DC-DC Converter

Abstract: In this paper, a new hybrid transformerless high voltage gain DC-DC converter is created by merging two-inductor boost converter with voltage multiplier and switched capacitor cells. The main advantages of the proposed converter is the high voltage gain, simplicity of operation, high efficiency, reduced voltage and current stresses on the components. A 200 W, 37.4 V/400 V, 100 kHz prototype was implemented in laboratory to evaluate the proposed converter, which reached a maximum efficiency of 98.24 %.

Switched-Capacitor and Coupled-Inductor-Based High Step-Up Converter With Improved Voltage Gain

Abstract: Based on a hybrid technique of coupled inductor (CL) and switched capacitor, a high step-up dc–dc converter is developed in this article. It consists of one active switch, one CL, four diodes, and four capacitors. The active switch withstands low voltage stress and all diodes’ voltage stresses do not exceed half of the output voltage. Simple structure and low-voltage-rated switches contribute to high efficiency of the proposed converter. The converter provides the ideal voltage gain of ( $2 + 2\,\,n) /(1 - d)$ , here $n$ represents the turns’ ratio of the CL and $d$ is the duty ratio. Its circuit configuration and operation principle are introduced. Effects of leakage inductance of the CL and parasitic resistance of components are analyzed in detail. The experimental results demonstrate the effectiveness of the proposed converter and the maximum efficiency is above 97%.

Neutral-Point-Clamped Five-Level Inverter with Self-Balanced Switched-Capacitor

Abstract: In this paper, a new 5-level inverter is developed by inserting a switched-capacitor (SC) unit into the traditional 3-level neutral-point-clamped (NPC) inverter phase-leg. The SC unit consists of two capacitors and one bidirectional switch, all of which withstand a quarter of the dc input voltage. Whilst increasing the output levels, the performance is also improved in terms of power loss, common-mode voltage, switching stress dv/dt and output filter. Compared to other 5-level inverters like the conventional NPC and active NPC 5-level topologies, the new solution not only reduces the number of components and simplifies the design, but also has the advantage of self-balanced capacitor voltages. The analysis, simulation and experiment indicate that the proposed inverter is suitable for a wide range of applications like renewable source grid-connected interfaces and motor drivers. Simulation and experimental results of grid-connected operation verify that the new inverter is capable of providing both active and reactive power to the grid. Its excellent performance is also experimentally evaluated by a 1.2 kW prototype and the measured efficiency is above 97% for a wide range of load.

Z-Network Plus Switched-Capacitor Boost DC–DC Converter

Abstract: In this paper, a Z-network plus switched-capacitor based DC-DC boost converter (ZSCBC) is proposed. The integration of the Z-network with a switched capacitor is responsible for yielding a high-voltage gain and that too at lower duty ratios compared to the conventional quasi-Z-source dc–dc converter (QZSC). Since the proposed converter contains Z or impedance network, the operating duty ratio is less than 0.5, such as in QZSC, and retains its advantages, such as common ground and low-voltage stress on Z-network capacitors. Unlike QZSC, the switch and all the diode voltage stresses in the proposed converter are low even at high-voltage gains. A detailed steady-state analysis is presented to identify the salient features of the proposed Z-network-based boost converter and thereafter compared with other Z-source-based configurations. The small-signal analysis is established, and a single-loop voltage-mode controller is designed. A 48–250-V, 130-W prototype is built to demonstrate the effectiveness of the ZSCBC. The steady-state and closed-loop response measurements validate the theoretical studies.

A T-Type Switched-Capacitor Multilevel Inverter With Low Voltage Stress and Self-Balancing

Abstract: This paper proposes a novel T-type multilevel inverter (MLI) based on the switched-capacitor technique. The proposed inverter not only achieves that the maximum voltage stress of the switches is less than the input voltage but also has a voltage boost capability, which makes it suitable in high voltage applications. It is worth mentioning that the proposed inverter features two topology extension schemes which help it achieve a higher output level and voltage gain. With the merit of low voltage stress and reduced power devices, a seven-level inverter can be achieved using only two capacitors. Moreover, capacitor voltage self-balancing capability can simplify the complexity of the circuit and control. The topology, operating principle, modulation strategy and analysis of the capacitor of the inverter are presented. The superiorities of the proposed inverter are investigated by comparing with recently proposed hybrid MLIs and switched-capacitor MLIs. Finally, a seven-level prototype is constructed to validate the correctness of the theoretical analysis and the feasibility and effectiveness of the proposed inverter.

A Reduced Device Count Single DC Hybrid Switched-Capacitor Self-Balanced Inverter

Abstract: Multilevel inverter (MLI) with switched-capacitor combinations have attained lots of attention for reducing the switch count, source count and control complexity. This brief discloses a cross-switched hybrid 13-level inverter (CHI) topology consisting of switched-capacitor circuits. The proposed CHI includes a single-dc source and only 12 switches to generate the 13-level triple voltage boost output. The desired output voltage levels are realized by self-balanced operation of the capacitors. The voltage across two capacitors is inherently maintained at input dc voltage ( ${V}_{in}$ ) and other two capacitors are self-charged to 0.5 ${V}_{in}$ , which reduces the control complexity. Comparative assessment with prior-art MLIs indicates the merits such as fewer devices and low voltage stress of proposed CHI. To ascertain the operational principles simulation and experimental results are finally acquired under several steady and dynamic conditions.

Marine Predators Algorithm Optimized Reduced Sensor Fuzzy-Logic Based Maximum Power Point Tracking of Fuel Cell-Battery Standalone Applications

Abstract: Fuel cell (FC) represents one of the promising efficient solutions for future energy supply. Improving performance and integration methods of FCs via maximum power point tracking (MPPT) and high boosting factor inverters are key requirements for research in renewable energy fields. Recently, hybrid FC-battery structures have shown wide applications in several areas. Accordingly, marine predators algorithm (MPA) is proposed in this article for optimizing the design of reduced sensor fuzzy-logic based MPPT scheme. The proposed scheme inherits the following benefits: reduced sensors and hence reduced costs, more flexibility and smooth performance due to fuzzy-logic based MPPT, and optimized design method of fuzzy-logic based MPPT through MPA method. Moreover, a high boosting ratio inverter is introduced in this article based on using the switched capacitor multilevel inverter (SCMLI). The proposed system achieves self capacitor voltage control without complex control or extra sensors. The proposed hybrid FC-battery system has been validated at various operating points. In addition, comprehensive comparisons with existing schemes in the literature are provided in the paper. The superiority of the proposed scheme has been verified with robust, fast and accurate tracking, reduced cost, flexible, simple, and smooth output waveforms. The proposed method achieves the lowest output power fluctuations with fast tracking speed compared to the studied classical methods.

Extendable Switched-Capacitor Multilevel Inverter With Reduced Number of Components and Self-Balancing Capacitors

Abstract: Multilevel inverters (MLIs) with self-balanced switched-capacitors (SC) have received wide recognition for increasing the reliability and efficiency of renewable energy and high-frequency power distribution systems. This article presents a new SC MLI structure using a reduced number of components. The proposed dual-source SC MLI can be extended in various ways to increase the voltage levels at the output. The SCs are self-balanced by using a suitable charging–discharging pattern, and thereby, voltage boosting is achieved. The operational analysis and features of the proposed 25-level MLI are delineated in detail. Comparative analysis with state-of-the-art MLIs in terms of the number of components, voltage stress, and cost factor demonstrate the merit of the proposed extendable SC MLIs. Extensive simulation of the proposed MLI structure is performed on the MATLAB/Simulink environment using both the low and high switching frequency control schemes. Furthermore, simulation results are validated experimentally by developing a prototype of the proposed MLI under load variations, frequency change condition, and variation in the modulation index.