Quantitative power loss analysis and optimisation in nth-order low voltage multilevel converters

Focusing on cascaded H-bridge converters for grid-tie battery energy storage, a practical, analytical method is derived to evaluate the switching-associated power loss in multilevel converters, evaluated from a number of sources of loss. This new method is then used to find performance trends in the use of converters of increasing order over a range of switching frequencies. This includes an experimental analysis into predicting the performance of MOSFET body diodes. Our analysis with this model shows that a multilevel converter can have lower losses than the equivalent single bridge, three-level converter, particularly at higher switching frequencies, due to the availability of suitable switching devices. It also has interesting implications for enabling the use of cutting-edge non-silicon power switching devices to further improve potential efficiencies

A Review on Different State of Battery Charge Estimation Techniques and Management Systems for EV Applications

Electric vehicles (EVs) have acquired significant popularity in recent decades due to their performance and efficiency. EVs are already largely acknowledged as the most promising solutions to global environmental challenges and CO2 emissions. Li-ion batteries are most frequently employed in EVs due to their various benefits. An effective Battery Management System (BMS) is essential to improve the battery performance, including charging–discharging control, precise monitoring, heat management, battery safety, and protection, and also an accurate estimation of the State of Charge (SOC). The SOC is required to provide the driver with a precise indication of the remaining range. At present, different types of estimation algorithms are available, but they still have several challenges due to their performance degradation, complex electrochemical reactions, and inaccuracy. The estimating techniques, average error, advantages, and disadvantages were examined methodically and independently for this paper. The article presents advanced SOC estimating techniques, such as LSTM, GRU, and CNN-LSMT, and hybrid techniques to estimate the average error of the SOC. A detailed comparison is presented with merits and demerits, which helped the researchers in the implementation of EV applications. This research also identified several factors, challenges, and potential recommendations for an enhanced BMS and efficient estimating approaches for future sustainable EV applications

A Review on Different State of Battery Charge Estimation Techniques and Management Systems for EV Applications

Electric vehicles (EVs) have acquired significant popularity in recent decades due to their performance and efficiency. EVs are already largely acknowledged as the most promising solutions to global environmental challenges and CO2 emissions. Li-ion batteries are most frequently employed in EVs due to their various benefits. An effective Battery Management System (BMS) is essential to improve the battery performance, including charging–discharging control, precise monitoring, heat management, battery safety, and protection, and also an accurate estimation of the State of Charge (SOC). The SOC is required to provide the driver with a precise indication of the remaining range. At present, different types of estimation algorithms are available, but they still have several challenges due to their performance degradation, complex electrochemical reactions, and inaccuracy. The estimating techniques, average error, advantages, and disadvantages were examined methodically and independently for this paper. The article presents advanced SOC estimating techniques, such as LSTM, GRU, and CNN-LSMT, and hybrid techniques to estimate the average error of the SOC. A detailed comparison is presented with merits and demerits, which helped the researchers in the implementation of EV applications. This research also identified several factors, challenges, and potential recommendations for an enhanced BMS and efficient estimating approaches for future sustainable EV applications

Experimental Implementation of Cascaded H-Bridge Multilevel Inverter with an Improved Reliability for Solar PV Applications

This study presents the boost converter-based cascaded H-bridge (CHB) multilevel inverter with improved reliability for solar PV (photovoltaic) applications. The solar PV is associated with the boost converter to enhance DC link voltage by using the maximum power point tracking-perturb and observe (MPPT-P & O) technique. The proposed configuration is aimed toward the performance analysis of the boost converter-based CHB MLI by reducing the number of components, low total harmonic distortion (THD), reduced power, less cost function, low total standing voltage (TSV), improved reliability, and switching losses for solar PV application. In this study, a CHB multilevel inverter is used to obtain stepped pure sinusoidal AC from the solar PV array. The proposed boost converter extracts maximum power and enhances higher DC link voltage which provides high efficiency. The boost converter is integrated with a 27-level CHB multilevel inverter to generate near-sinusoidal output voltage with lower THD. The inverter is tested with linear and nonlinear loads for robustness, and during dynamic loads, inverter is stable and well suited to grid-connected applications. A detailed comparison is presented on the component count and reliability aspects with existing MLIs and 27-level MLIs. The simulation outcomes of the implemented arrangement are presented with the help of MATLAB/Simulink, an experimental prototype is developed using a dSPACE RTI1104 controller and also tested in the research laboratory for checking the possibility of the implemented arrangement

An Overview on Multi-Level Inverter Topologies for Grid-Tied PV System

Over the years, multi-level inverter (MLI) usage has increased widely for several applications like motor drives, renewable energy source- (RES-) fed grids, and electric vehicles (EVs). In recent scenarios, the development of RES, grids, and EVs is in advanced mode, and this became the reason for innovations in recent MLI topologies. The new topologies have more advantages, unique features, and abilities to meet the advanced requirements. Therefore, these new topologies are preferable for recent applications. In this paper, a detailed review of recent MLI topologies, controllers, and PWM techniques is done by considering some physical aspects as well as some performance aspects. Also, the particular focus is on the MLI topologies, controllers, and PWM techniques for photovoltaic (PV) system-fed grids and microgrids to provide details for selecting the suitable MLI topology and PWM technique for PV systems. The detailed analysis of each topology is discussed for categorizing specific applications along with futuristic expansion aspects. The future research scope on MLI topologies for PV systems is summarized with appropriate comprehensive comparisons along with their unique features over other topologies. Also, the advanced controllers and PWM techniques are also discussed with advantages and their wide range of controlling abilities

Artificial Neural Network and Newton Raphson (ANN-NR) Algorithm Based Selective Harmonic Elimination in Cascaded Multilevel Inverter for PV Applications

In this article, a hybrid Artificial Neural Network - Newton Raphson (ANN-NR) is introduced to mitigate the undesired lower-order harmonic content in the cascaded H-Bridge multilevel inverter for solar photovoltaic (PV). Harmonics are extracted by the excellent choice of opting switching angles by exploiting the Selective Harmonic Elimination (SHE) PWM technique accompanying a unified algorithm in order to optimize and reduce the Total Harmonic Distortion (THD). ANN is trained with optimum switching angles, and the estimates generated by the ANN are the initial guess for NR. In this study, the CHB-MLI is combined with a traditional boost converter, it boosts the PV voltage to a superior dc-link voltage Perturb and Observe (P&O) based Maximum Power Point Tracking (MPPT) algorithm is used for getting a stable output and efficient operation of solar PV. The proposed system is proved over an eleven-level H-bridge inverter, the work is carried out in MATLAB/Simulink environment, and the respective results are confirmed that the proposed technique is efficient, and offers an actual firing angles with a few iterations results in a better capability of confronting local optima values. The suggested algorithm is justified by the experimental development of eleven-level cascaded H-bridge inverter

A structural overview on transformer and transformer-less multi level inverters for renewable energy applications

In general, multilevel inverters (MLIs) are regarded as advanced power conversion systems required for medium-voltage and high-power applications. The purpose of this article is to provide an overview of recently investigated MLI topologies classified into various categories based on the transformer requirement such as the transformer less (TL-MLI) and transformer-based (T-MLI) with single and multi-source topologies of symmetric, asymmetric, hybrid and single DC sources for renewable energy applications. For the previous few decades, multiple new variants of each group have been developed. The design and functioning of each topology, as well as each group, are examined in this study. T-MLI topologies of H-bridge, three-leg inverter-based, and other T-MLI configurations are discussed from a configuration standpoint. Each topology's state-of-the-art of both MLI configurations and problems are treated separately. Furthermore, the disadvantages and benefits of each topology have been thoroughly addressed. Finally, a comparison of existing topologies is conducted to determine the optimal topology based on several performance characteristics and the cost evaluation has been presented. This article provides a comprehensive overview of recently developed multilevel inverters and provides a solution for developing the MLIs for future research on renewable energy applications. 2022 The AuthorsThe publication of this article was funded by Qatar National Library .Scopu

A Single Inductor Multi-Port Power Converter for Electric Vehicle Applications

This research presents a non-isolated multi-port power converter feasible to hybridize energy alternatives in electric vehicles. Due to the hybridization of the various input sources, there are several advantages in load power distribution in the system. Flexible control of discharging as well as the charging process concerning the energy sources can be achieved. The developed converter can able to boost the voltage levels with dual inputs such as a renewable solar PV and the other input as a battery and provides dual outputs with various voltage levels, which can able to suit the converter fed for several loads like motor drive and the low-rated loads like lighting and other auxiliary supplies in electric vehicles. Also, as the various voltages appear at the output, this converter can be interfaced with multilevel inverters fed electric vehicle drivetrain. The utilization of multilevel inverters reduces the total harmonic distortion and torque ripples in motor drives in electric vehicles. The proposed converter consists of less number of components making the circuit simple and cost-effective. With one inductor, two various modes are obtained for charging and discharging states concerning the energy storage units. A state-space analysis is designed for all the converter operating modes along with its control design. The proposed multi-port DC-DC converter is designed in MATLAB/Simulink and tested in a laboratory environment with a hardware setup. 2013 IEEE.Open Access funding provided by the Qatar National Library.Scopu