Reduced Switch Multilevel Inverter Research Articles

Performance evaluation of novel 9-level RSMLI topology for grid-tied solar-PV system

The shortage of traditional fossil fuels like coal, petrol and natural-gas are increased day-by-day, fulfills the most of energy demand. Most of engineers are trying to maximize the energy demand by employing renewable energy with existing micro-grid system. Owing to merits, the solar-PV system plays a significant alternative among all other renewable energy sources due to abundant and virtuous nature. For grid-tied solar-PV system, the cascaded H-bridge multilevel inverter is the most significant over the classical 2-level inverter due to provision of isolated input DC sources. But the cascaded H-bridge topology is designed for limited voltage levels due to its larger number of switches for higher voltage levels, high cost, large-size, and more weight. To alleviate these demerits, a reduced-switch multilevel inverter has been generally preferable for higher voltage levels. In this work, a novel 9-level reduced-switch multilevel inverter (RSMLI) topology has been proposed by utilizing low number of switching devices. The performance of proposed novel 9-level RSMLI topology has been verified in grid-tied solar-PV system by using MATLAB/Simulink tool, simulation results are presented with attractive comparisons.

A Novel Multilevel Inverter for Renewable Energy Applications with Optimized Controller and Reduced Switches

Multilevel converters have the capability of handling high power as well as deliver output with reduced harmonics. So they can be implemented with renewable energy sources to produce multilayer output with symmetric cascade arrangement with reduced switches. Here the control technique is developed in such a way to reduce the harmonics in the grid integrated PV system. The paper proposes optimized Fractional Order Proportional Integral Derivative (FOPID) controller for a seven level reduced switch multilevel inverter. The War Strategy Optimization Algorithm (WSOA) which utilizes optimizing the strategic movements of armed forces (assault and defend) towards the final optimal value is used to optimize the FOPID controller. This WSOA algorithm is used to adjust the gain parameters of the FOPID controller there by improving the system performance. The characteristics of grid connected PV system are regulated by implementing this suggested technique. The projected approach is incorporated using MATLAB / Simulink and the performances are evaluated and compared with the conventional techniques like GA – PID and WSOA – PID controllers.

Reduced Switch Multilevel Inverter Based Shunt Active Power Filter With ANN Controller for Power Quality Improvement

In order to improve power quality, this research investigates the use of SAPF with Seventeen Level Reduced Switch Multilevel Inverter. The electricity grid's stability is significantly influenced by various non-linear loads. To address this, SAPF is proposed and designed to monitor, manage the current movement between the power source and the load. The variance between the intended and real currents drawn from utility grid is assessed using p-q theory based hysteresis current controller. The calculated error current guides the controllers in forecasting the best-suited switching signals and modulation index for the seventeen level RSMLI-SAPF system. In this paper the traditional PI controller, Artificial Neural Network based controller are compared and the results are provided to validate the performance of SAPF. The proposed system is modelled and analysed using MATLAB/Simulink. The simulation results are provided for various modulation index using Hybrid Pulse Width Modulation in which Triangle saturated Phase disposition PWM using Unipolar Third harmonic injection as Reference is used and are subjected to non-linear loads.

Moth flame algorithm-based optimization of a reduced switch multilevel inverter topology suitable for standalone application

Moth flame algorithm-based optimization of a reduced switch multilevel inverter topology suitable for standalone application

CSA-based harmonic elimination controlled reduced switch multilevel inverter for standalone PV system

A standalone photovoltaic (PV) system has emerged as a clean energy solution for application in remote areas. To establish such a system a suitable converter is required for voltage boosting as well as to produce high-quality output as required by the load. To achieve this, multilevel inverters (MLIs) are the proven substitute in PV systems. A conventional MLI uses multiple sources and switches that increase the cost and complexity. To provide a complete stand-alone system solution that addresses this issue, reduced component switched capacitor (SC) based seven-level MLI is disclosed in this paper. A new crow search algorithm (CSA) based selective harmonic elimination (SHE) method is employed to estimate the switching angles. The dominant harmonic orders are removed from the 7-level SC-MLI output while the desired firing angles for the switches are evaluated. Using only seven switches, the circuit boosts the voltage to 1.5 times with the aid of self-balanced capacitors. Therefore, the circuit does not require an additional control circuit for voltage balancing. The overall system is designed in MATLAB/Simulink environment to test under different operating conditions. An experimental prototype of the 7-level SCMLI is also designed to validate the CSA-based SHE control and MLI performance in real time.

A novel 7-level reduced-switch MLI topology fed PMSM drive for electric vehicle system

The compact and efficient design motivates the renewable energy-powered permanent magnet synchronous motor drive for electric vehicle applications. The available renewable energy is interfaced with a power drive by employing an electronic commutator such as a conventional 3-level inverter. But, the multilevel inverter produces favorable merits by producing staircase output voltage from several input direct current (DC) sources. The cascaded H-bridge multilevel inverter plays a significant role in many applications, but it was developed only for limited voltage levels. The major problem in cascaded h-bridge multilevel inverter (CHBMLI) requires more switching devices for higher voltage levels, which increases the size, cost and space of the electric vehicle (EV). To overcome above-mentioned problems, a new objective has been developed by employing the novel Reduced-switch multilevel inverter topology for higher voltage levels. This improves the voltage quality and reducing the harmonic level, and common-mode voltage issues. The main contribution of this work is, developing the novel 5-level, 7-level reduced-switch multilevel inverter (RSMLI) topologies with reduced switching devices with favourable merits over CHBMLI topology. Finally, the performance of proposed novel 5-level and 7-level RSMLI topologies fed PMSM drive for EV system has been verified, by using MATLAB/Simulink computing tool, and simulation results are presented with comparisons.

Lower Output Voltage Harmonics With Optimum Switching Angles of Single PV-Source Based Reduced Switch Multilevel Inverter Using BWO Algorithm

Lower Output Voltage Harmonics With Optimum Switching Angles of Single PV-Source Based Reduced Switch Multilevel Inverter Using BWO Algorithm

Assessment of hybrid MPPT for SPV based high gain cubic boost converter interfaced with reduced switch multilevel inverter for power quality enhancement

A high-gain cubic boost converter (HG-CBC) with hybrid-based maximum power point tracking (MPPT) through a neural network (NN) aided by the P&O technique (HNN-PO MPPT) has been suggested to acquire optimum power from a solar photovoltaic (SPV) model under varying climatic conditions. The SPV’s output is enhanced using the suggested HG-CBC as per the requirement. A detailed comparison of different conventional boost converters (BC) with the suggested HG-CBC is presented, mainly highlighting part count and boost factor (B). Using the MATLAB tool, the functionality of the developed HNN-PO MPPT technique has been examined for constant and different irradiation (G) levels. The hybrid-based MPPT helps quickly attain maximum power point (MPP) with minimum oscillations at the output. The convergence period is very short with high precision in comparison with P&O and NN MPPT. The results are examined between the suggested and traditional MPPT methods in relation to the percentage of oscillations and rise time. The Reduced Switch Multilevel Inverter (RSMLI) is proposed to integrate the SPV with the RL load. The RSMLI is compared with the conventional standard five-level MLI in relation to the quantity of DC sources, diodes, switches, capacitors, and other parts utilized. The suggested MLI involves a reduced switch count, which mitigates the overall losses during switching and hence improves the efficiency of an inverter. MLI switches are controlled using a sine Pulse Width Modulation (PWM) technique. The THD of the output current of a five-level RSMLI is 4.47%, and it falls within the IEEE 519 norm. Hence, output power quality is enhanced.

Mitigation of PQ issues in EV charging station connected distribution system using novel RSMLI-based shunt APF

<span>In the present scenario, the significant use of electric vehicles (EVs) is growing rapidly in the automotive industry due to cheaper transportation, no fossil fuel required, low maintenance, no fuel cost, and low impacts on the environment over the formal internal combustion engine (ICE) vehicles. In actuality, these EVs are powered by batteries that are charged by a utility-grid-based charging facility. A power-electronic conversion-based charging device is used in this charging station to charge the battery packs in the EV system. The problem statement of this work is identified, these conversion devices in charging units proliferate the power quality of the utility grid. To overcome these problems, a classical square-wave inverter-based active power filter (APF) is employed. The major problems in classical inverters are high common-mode voltage, more harmonic profile, high dV/dt stress, high switching stress, and low efficiency. The contribution of this work is proposing the multilevel inverter (MLI) based APF for better compensation over classical inverters. In this approach, a novel reduced-switch MLI-based APF has been proposed for the mitigation of harmonic currents and also enhances the power factor in utility-grid-connected distribution systems. The effectiveness of the proposed reduced-switch multilevel inverter (RSMLI)-APF is validated by integrating the number of charging units with the MATLAB/Simulink tool, and simulation outcomes are shown along with comparisons.</span>

A double T‐type H‐bridge reduced switch multilevel inverter for a wide range of DC voltage variations

AbstractRenewable energy sources are subject to input source uncertainties, which can negatively impact output voltage THD. Having a high number of voltage levels in multilevel inverters (MLIs) with minimum components is cost‐effective. This paper proposes a new structure, Double T‐type H‐bridge (DTH) module, that can produce 9, 13, 17, 19, 21, and 25 levels using reduced components. Switching patterns in MLIs refer to the way in which the power switches are controlled to generate the desired output voltage waveform. As a result, having more switching patterns make the converter flexible to produce voltage levels in the face of input source uncertainties. The DTH structure provides new switching patterns, making it possible to produce levels when the difference of capacitor voltage is negative in a positive cycle or vice versa. This paper presents a new algorithm based on nearest level control to order voltage levels in ascending order, which improves output THD significantly. This topology brings a lower switching state that is linked to switching losses directly compared to the topologies with the same number of power switches. The DTH module's performance is evaluated through graphical analysis, simulations, and experimental results in symmetrical, asymmetrical, and load change conditions.

Hardware Design and Implementation of FPGA Controlled Seven-Level Reduced Switch MLI

The paper proposes the design of a seven-level reduced switch multi-level inverter (7LRS-MLI) topology. The design produces a seven-level staircase output waveform with fewer components (seven power switches), thus reducing the cost and area and improving the performance of the design, i.e. increasing efficiency and reducing switching loss effectively. Both symmetric and asymmetric configurations have been implemented and the results are discussed in the paper. A comparison of the proposed structure with other recent seven-level structures has been illustrated. The simulation (using MATLAB/SIMULINK software) and experimental validation of 7LRS-MLI also have been performed for R, RL load, change in load and change in a modulation index (MI). Field programmable gate arrays (FPGA) have been used for digital implementation of the switching waveforms which reduces design time and improves flexibility. For switching devices, the alternative phase opposite disposition pulse width modulation (APOD-PWM) technique is used at 500 Hz and 5 kHz. The voltage and current total harmonic distortion (THD) profiles are also computed during the simulation and experimental validation.

Modulation Technique Based on Low Computational SVPWM for Reduced Switch Multilevel Inverter Hardware Implementation

Modulation Technique Based on Low Computational SVPWM for Reduced Switch Multilevel Inverter Hardware Implementation

Performance evaluation of grid connected photovoltaic system using novel HTLB-WOA regulated VPFOTADF controller

The aim of this manuscript is the design of Hybrid Teaching Learning Based-Whale Optimization Algorithm -Variable Parameter Fractional Order Tilt Acceleration Derivative with Filter (HTLB-WOA regulated VPFOTADF) controller to reduce the harmonic distortion and improving performance of grid connected solar photovoltaic system. The solar photovoltaic system consists of components like photovoltaic array, interleaved fractional order boost converter, Reduced Switch Multilevel Inverter (RSMI) and HTLB-WOA regulated VPFOTADF controller. Interleaved fractional order boost converter is preferred over boost converter because of its low ripple voltage, faster transient response, high efficiency, low duty cycle, reduced EMC and improved reliability and stability. In this control strategy the control logic is formulated by using a Tilt Integral Derivative Controller (TIDC), whose control parameters are considered as a function of error to improve the robustness. The validation, better performance and superiority of HTLB-WOA regulated VPFOTADF is established by comparative result analysis with other state of the art controllers. HTLB-WOA regulated VPFOTADF along with Direct and Quadrature Control based Sinusoidal Pulse Width Modulation (DQC-SPWM) technique is implemented in this manuscript. This proposed model is analyzed for reduction in harmonic, improved system performance, better accuracy, improved stability, improved robustness and better capabilities to handle system uncertainties.

Power Quality Improvement of a Reduced Switch MLI Using a Modified ANN-Based SHE Technique

A cross-connected source (CCS) based multilevel inverter (MLI) is proposed for the generation of “9” and 13-levels using asymmetrical switching. The reduced switch CCS-MLI is controlled with a low frequency selective-harmonic-elimination pulse-width-modulation (SHE-PWM) strategy. The switching angles are synthesized by solving SHE equations utilizing the proposed modified artificial-neural-network (ANN) like architecture. The ANN can solve multiple transcendental equations starting from random initial guess points and without any initial data. This adds a significant improvement to the existing techniques that suffer severely with an increased number of SHE equations to be solved. To verify these unique features of the modified ANN, a CCS-MLI is realized with a higher number of levels. The enhanced performance and reasonable convergence rate of the ANN validate the suitability of the proposed control. Furthermore, CCS-MLI is simulated for resistive-inductive load considering THD as a performance parameter. The power quality improvement of the proposed inverter is shown for different modulation index (MI) and significantly low THD is reported for both “9” and 13-level case. Experimental results of a hardware prototype are also illustrated. Furthermore, the proposed system is implemented as a central inverter of standalone PV system to test its practical feasibility.

Solar Photovoltaic System-Based Reduced Switch Multilevel Inverter for Improved Power Quality

This paper deals with a reduced switch multi-level inverter for the solar photovoltaic system-based 127-level multi-level inverter. The proposed technique uses the minimum number of switches to achieve the maximum steps in staircase AC output voltage when compared to the flying capacitor multi-level inverter, cascaded type multilevel inverter and diode clamped multi-level inverter. The use of a minimum number of switches decreases the cost of the system. To eliminate the switching losses, in this topology a square wave switch is used instead of pulse width modulation. Thereby the total harmonic distortion (THD) and harmonics have been reduced in the pulsating AC output voltage waveform. The performance of 127-level MLI is compared with 15 level, 31-level and 63-level multilevel inverters. The outcomes of the solar photovoltaic system-based 127-level multi-level inverter have been simulated in a MATLAB R2009b environment.

ANN Based Reduced Switch Multilevel Inverter in UPQC for Power Quality Improvement

A unified power quality conditioner (UPQC) plays a crucial role in the Power quality improvement of a power system. In this paper, a reduced switch multilevel inverter is with artificial neural network, soft computing technique control is proposed for UPQC. This proposed topology is employed for the mitigation of various power quality issues such as voltage sag, voltage swell, power factor, harmonics, and restoration time of voltage compensation. To show the enriched performance of the proposed topology comparative analysis is made with other two topologies of UPQC such as Conventional UPQC and UPQC using cascaded H bridge (CHB) five-level Inverter. All configurations are analysed using Matlab with variable nonlinear loads to analyse the performance during the conditions mentioned above.

A New Hybrid Cascaded Switched-Capacitor Reduced Switch Multilevel Inverter for Renewable Sources and Domestic Loads

This multilevel inverter type summarizes an output voltage of medium voltage based on a series connection of power cells employing standard configurations of low-voltage components. The main problems of cascaded switched-capacitor multilevel inverters (CSCMLIs) are the harmful reverse flowing current of inductive loads, the large number of switches, and the surge current of the capacitors. As the number of switches increases, the reliability of the inverter decreases. To address these issues, a new CSCMLI is proposed using two modules containing asymmetric DC sources to generate 13 levels. The main novelty of the proposed configuration is the reduction of the number of switches while increasing the maximum output voltage. Despite the many similarities, the presented topology differs from similar topologies. Compared to similar structures, the direction of some switches is reversed, leading to a change in the direction of current flow. By incorporating the lowest number of semiconductors, it was demonstrated that the proposed inverter has the lowest cost function among similar inverters. The role of switched-capacitor inrush current in the selection of switch, diode, and DC source for inverter operation in medium and high voltage applications is presented. The inverter performance to supply the inductive loads is clarified. Comparison of the simulation and experimental results validates the effectiveness of the proposed inverter topology, showing promising potentials in photovoltaic, buildings, and domestic applications. A video demonstrating the experimental test, and all manufacturing data are attached.

A Dual-Source Self-Balanced Switched-Capacitor Reduced Switch Multilevel Inverter With Extending Ability

Multilevel inverters (MLIs) with switched-capacitor (SC) combinations are widely recognized to improve the power quality and efficiency of the renewable energy and high-frequency power distribution systems. Self-balancing of SCs and voltage boosting ability are the salient features of the recently developed SC MLIs. This work presents a new SC MLI structure using a reduced number of switches and two dc sources. For increasing the voltage levels, the basic units of the proposed MLI can be extended without increasing the number of dc sources. By suitable charging-discharging patterns, the SCs are self-balanced and voltage boosting is achieved. Comparative analysis with prior-art MLIs demonstrates the merit of topological advancement. Further, extensive simulation and experimental results confirm the feasibility of the proposed MLI under different loading and dynamic operating conditions.

A Reduced Switch Multilevel Inverter Connecting PV System with Power Grid through an Islanding Switch

A Reduced Switch Multilevel Inverter Connecting PV System with Power Grid through an Islanding Switch

Real time simulation of reduced switch multilevel inverter with PWM switching sequence control

<span lang="EN-US">Reduction of switch count in symmetrical and asymmetrical reduced switch multilevel inverter designs has been proposed regularly with operation of conventional carrier-based pulse width modulation technique. In this study, a novel structure of symmetrical Hexa shaped model reduced switch seven level output inverter is proposed without any auxiliary switch and H-bridge. Proposed structure offers a smaller number of switch count and voltage sources which results in the cost and complexity reduction of its implementation. To operate the switching sequence of inverter from carrier based APOD, POD and PD methods, suitable logical expression to be realize which gained more prominence. Active utilization of two voltage sources in each mode of operation results in significant reduction of voltage stress across each switch is achieved. A comparative study of proposed MLI with various reduced switch MLIs has been presented. Initially, simulation model implementation has been carried out with MATLAB/Simulink and observed the performance parameters and THD. Simulation results are carried for the comparison of the results obtained in the real time work performed on OPAL-RT 5700 simulator</span><span lang="EN-US">.</span>