This paper describes a high-definition sinusoidal pulse width modulation (HD-SPWM) based control of a reduced switched multilevel inverter (MLI). The inverter synthesizes seven-level voltage waveform by utilizing six active switches, and two isolated DC sources in its topology. A detailed operation of the MLI is presented with appropriate switching states of the topology. Furthermore, HD-SPWM based modulation technique is formulated for the seven-level inverter to achieve better power quality and overall reliability. To verify the industrial applicability, the designed system is simulated in MATLAB SIMULINK platform with resistive (R) as well as inductive (L) type loads. Various dynamic conditions such as variable load, changing output modulation index (MI) & frequency, are also considered for testing to explore the versatility of the topology and its formulated control. Additionally, the designed system exhibits competitive device count and reduced total harmonic distortion (THD). thus, the MLI topology with formulated HD-SPWM control will be particularly suitable for grid integration of distributed energy resources (DER).

In this study, a multilevel inverter design with only six switches and two DC voltage sources is presented for renewable energy purposes. With the design that is simulated in high frequency-based Multi-Carrier Pulse Width Modulation Techniques (MCPWM), asymmetrical DC sources provide an output voltage with seven levels. This reduces the size, cost, and overall number of components in the system. The inverter is experimentally tested with R and RL loads, as well as dynamic load variations with sudden changes in load. Four distinct MCPWM strategies - Variable Frequency PWM (VFPWM), Phase Opposition Disposition (POD), Phase Disposition (PD), and Alternate Phase Opposition Disposition (APOD) with changing Modulation Index (MI) - have been studied using the suggested inverter as a single phase. The Total Harmonic Distortion (THD) obtained for several MCPWM techniques following topology simulation in MATLAB/Simulink is shown in the results section. To confirm the accuracy, a thorough comparison of the THD value with other topologies is also performed.

The increasing demand for renewable energy integration in academic institutions, as well as any other sector, makes the potential of rooftop solar photovoltaic (PV) systems a sustainable solution. This paper presents the detailed design and techno-economic analysis of an on-grid solar photovoltaic (PV) system for Chittagong Independent University (CIU), Jamal Khan campus. This design proposes the detailed calculation of the rooftop solar PV system of the CIU campus according to the area provided by the authority. The design incorporates optimised solar panel placement based on rooftop area, local solar irradiance data, and institutional load demand.

This study proposes using a 15-level cross-connected sources-based multilevel inverter (CCS-MLI) to apply in photovoltaic (PV) power generation. The inverter topology is realized with ten active switches and four DC sources. The CCS-based multilevel inverter produces an output voltage waveform with fifteen levels, while the DC source voltages are maintained at appropriate levels. A high-frequency control method called multi-carrier pulse width modulation (MCPWM) is proposed to control the switching states of the 15-level CCS-MLI. All the carriers remain in phase when the equal frequency approach of Phase Disposition (PD) is used. The simulation is performed using the MATLAB/Simulink environment. The simulation outcomes illustrate that MCPWM with the PD technique can significantly reduce the total harmonic distortion (THD) in the output of 15-level CCS-MLI. Moreover, the effectiveness of the topology & its control is verified with resistive and inductive loads. The system is further simulated for variable load, modulation index, and frequency to validate the dynamic performance for industrial applications. The superior harmonic profile and stable dynamic performance indicate the suitability of the designed system as a solar inverter for standalone or grid-tied applications.

This work reports twelve switches cascaded H bridge (CHB) multilevel inverters (MLI) for asymmetrical input sources and high frequency control strategies. The proposed inverter consists of only twelve switches and is able to generate up to 27 level through asymmetrical switching as well as high frequency-based multi-carrier pulse width modulation (MCPWM) techniques. All the expressions for the switch logic to generate 7 level to 27 level are provided in the methodology sections and a few simulation results are plotted for the realization of the control techniques. As the proposed inverter is capable to generate higher levels with the suggested control strategy, the topology will automatically be claimed as a reduced switch and component count structure. The total harmonic distortion (THD) is improved in the output as the number of levels is getting increases.

This article presents a natural capacitor voltage balancing technique of packed U-cell (PUC) inverter extended for nine level topology realized by three floating capacitors and one DC source. The floating capacitors are charged to the voltage levels that maintain asymmetrical relationship between themselves and the DC source. The maximum inverter output voltage can reach up to the available DC source magnitude. With the proposed modulation technique, successful capacitor voltage balancing is possible for a nine -level packed U-cell (PUC9) inverter with three units of floating capacitor in its topology. The proposed modulation strategy achieves zero energy exchange between each capacitor and the remaining circuit. Thus, the need for any additional sensing equipment or complicated close loop control to achieve capacitor voltage balancing is eliminated. The singular DC source is realized with solar and battery combinations that are connected to inverter through unidirectional and bidirectional DC/DC converter respectively. This further verifies the robustness of control strategy as it considers practical scenario of a certain degree of voltage ripple across dc link capacitor of the DC/DC converter. Furthermore, the water pumping system is realized with a single-phase induction motor (IM). Stable operation of the said motor is established by integrating a close-loop V/f strategy with the modulation technique of solar inverter. The pumping system is simulated in MATLAB to validate its performance. A laboratory prototype is also built and tested with a resistive-inductive (RL) load to show the capability of the proposed open loop voltage balancing control of the solar inverter.

Designing of a reduced switch multi-string cross-connected source type multilevel inverter (CCS-MLI)-based solar pump is introduced in this article. Integration of the Photovoltaic (PV) system with the inverter is achieved through a DC–DC converter equipped with maximum power point tracking (MPPT) to enhance overall reliability. The asymmetrically switched CCS-MLI utilizes only 8 switches to generate 13-level waveform and facilitates power control between battery-assisted PV panels and the single-phase Induction Motor (IM). Multicarrier Pulse Width Modulation (MCPWM) is employed for frequency and fundamental component control in the output voltage. Solar-powered drive systems face the challenge of maintaining intended motor operation amid varying power generation from the PV array. The addition of batteries through a bidirectional DC/DC converter, mitigates this issue by supporting the load during reduced power output from PV panels due to unpredictable solar irradiation levels. Besides ensuring power quality, the proposed control technique realizes constant (V/f) control enabling stable drive operation. The efficacy of the proposed scheme is tested in MATLAB SIMULINK platform with a solar battery combination, considering changing environmental conditions. Furthermore, a hardware prototype of the battery-assisted CCS-MLI-based solar inverter is implemented, and various results are rigorously tested and analyzed using an equivalent machine circuit.

In this work a reduced component count single sourced based multilevel inverter (SSMLI) is proposed. The inverter is essentially designed for the modular version which means it can be utilized for any number of levels to achieve the desired power quality. There are two types of modulation and control strategies are used for the feasibility study of the proposed inverter. At first, multi-carrier pulse width modulation (MCPWM) strategy is realized to visualize the high frequency control. After that low frequency based SHE control through artificial neural network (ANN) algorithm is proposed. The power quality i.e. total harmonic distortion (THD) is compared for both the control techniques to understand the improvement of power quality for the designed inverter. For the simulation and descriptive analysis the 9 level inverter is selected and realized. The proposed inverter will be suitable for renewable power generation especially for stand-alone solar PV applications.

In this work, a reduced component count multilevel inverter (RCCMLI) topology of only six switches and two DC sources is proposed, which is simulated in high frequency-based Multi-Carrier Pulse Width Modulation Techniques (MCPWM). As the conventional converters add more switches and component counts including high THD output, reduced component count topology is proposed in this paper. Besides, high-frequency control with asymmetrical DC inputs uplifts the output voltage level for the selected inverter. The proposed inverter is analyzed for both single and three-phase modes for four types of MCPWM strategies such as Phase Disposition (PD), Phase Opposition Disposition (POD), Alternate Phase Opposition Disposition (APOD), and variable Frequency PWM (VFPWM). Total Harmonic Distortion (THD) achieved for different methodologies of MCPWM is comparatively shown in the simulation and results section. For single-phase simulation voltage, THD is 9.03% with seven-level output, and for three-phase current THD is 1.63% with thirteen-level output. The simulated single and three-phase inverters can be used for solar power generation, especially for stand-alone and grid-connected applications.

This work reports a reduced component count multilevel inverter (MLI) for single and three phase applications. The selected inverter is simulated for different types of low frequency harmonic mitigation techniques to achieve better Total Harmonic Distortion (THD) performance with a good power quality. The inverter is simulated for both single and three phase mode with R, RL, and dynamic loads to ensure its feasible operation. For single phase 7 level is generated with non-uniform DC inputs and for three phase 13 level is achieved automatically according to MLI operation and control.

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.

This article presents a solar-inverter utilizing a seven-level packed U-cell (PUC), with single DC source and two floating capacitors in its topology. The capacitor voltage is balanced in open-loop by implementing multicarrier pulse width modulation (MCPWM) technique. Furthermore, water pumping system is realized with a single phase induction motor (IM)of 1.4KW rating. Stable operation of the said motor is established by integrating close-loop V/f strategy with modulation technique of solar inverter. For this work solar panels of 1.6KW are incorporated to design the PV system. Maintaining optimum performance of any solar powered drive is a major challenge due to unpredictable nature of environmental conditions that effects the power generation capability of PV panels extensively. To address this issue a topology combining battery pack as well as solar panel is proposed as a single DC source of the packed-U cell. This increases the overall reliability of the system. The battery pack is integrated with the solar inverter through a bidirectional DC/DC converter to enable its charging as well as discharging depending on the available power output of the photo-voltaic (PV) arrays. The PV panels are connected with the DC link capacitor of the battery unit through a unidirectional DC-DC converter. A maximum power point tracking (MPPT) strategy is implemented to enable maximum power extraction from these panels.

This article presents a solar-inverter driven single phase induction motor (IM) drive by utilizing a reduced switch multi-string cross-connected source type multi-level inverter (CCS-MLI) for water pump application. Photovoltaic (PV) system has been integrated with water pumping system through DC-DC converter with maximum power point tracking (MPPT) to improve system reliability. This is more suited to developing nations like India, where electrical power consumption is increasing, and agriculture is a major source of income for many Indians. A 13-level CCS-MLI is used to control the power between PV panels and single-phase IM. To achieve 13-level the inverter employs only eight switches while switched asymmetrically. Control of frequency, fundamental component and total harmonic distortion (THD) at the output voltage is realized with multicarrier pulse width modulation (MCPWM). The fundamental challenge with solar-powered drive systems is maintaining the drive's intended operation when the PV array's power generation varies. In addition to maintaining power quality, the proposed control technique establishes V/ f control of single-phase IM and ensures stable operation of the drive system under unpredictable environmental conditions. Furthermore, the proposed scheme is simulated in MATLAB with 1.6 KW PV panel and drive performance is verified with changing environmental condition.