This paper presents a hybrid control strategy which combines the nearest level control technique with PWM control technique on a cascaded H-Bridge Multilevel Inverters (MLI). MLIs have become very popular due to its several advantages in the application areas like industrial drives and grid-connected renewable energy generation systems. With the reduced number of switches, driver circuits, conduction losses, switching losses, voltage stresses, size, and cost of the system, MLI has outperformed its two-level counterpart in terms of power quality issues. Reduction in the Harmonics and consequently the Total Harmonic Distortion (THD) in the output voltage has added to the benefits of MLI. Topological advancements in MLI require a satisfactory output voltage control strategy. In this work, a hybrid control strategy for a smooth and wider range of control of output voltage is proposed. The hybridized scheme enhances the control range of the voltage considerably. Moreover, the THD is also reduced compared to the conventional sinusoidal PWM scheme. A thorough analysis of the scheme has also been presented in the paper. SIMULINK/ MATLAB environment is used for testing the simulation model of the proposed control scheme. This hybridized controlling technique is also simulated for thermal modelling on PLECS software and power loss analysis is performed. The mathematical and simulation analyses are validated on an experimental prototype using a TMS320F28335 DSP controller card. The hybrid scheme has also been tested for a fault tolerant model of the cascaded H-bridge inverter. The performance of the hybrid scheme under different fault condition has also been shown to work satisfactorily.

This paper presents the Archimedes optimization algorithm to eliminate selective harmonics in a cascaded H-bridge (CHB) multilevel inverter (MLI). The foremost objective of the selective harmonic elimination (SHE) is to eliminate lower order harmonics by finding the optimal switching angle combination which minimizes the objective function containing Total Harmonic Distortion (THD) and other specific harmonic terms. Consequently, the THD is also reduced. In this study, a recently proposed metaheuristic technique named the Archimedes optimization algorithm (AOA) is used to determine the optimal angles corresponding to the 5, 7 and 9 level CHB-MLI. AOA involves equations related to a physical law, the Archimedes Principle. It is based on the idea of a buoyant force acting upward on a body or object that is partially or completely submerged in a fluid, and the upward force is related to the weight of the fluid displaced. This optimization technique has been implemented on CHB-MLI to generate various level outputs, simulated on MATLAB™ R2021a version environment software. The simulation results reveal that AOA is a high-performance optimization technique in terms of convergence speed and exploitation-exploration balance and is well-suited to the solution of the SHE problem. Furthermore, the laboratory validated the simulation result on a hardware setup using DSP-TMS320F28379D.

A single-phase five-level T-type topology has been investigated in this article. This topology has emerged as a viable option for renewable energy systems (RES) due to its inherent benefits. The finite control set model predictive control (FCS-MPC) strategy has been implemented to this topology in order to improve the performance and overall reliability of the system. This control strategy empowers the inverter to predict future behavior based on a discrete set of control signals, enabling precise modulation and high-speed response to system dynamics. In the realm of RES, integration of FCS-MPC with multilevel inverters (MLIs) holds great potential to enhance energy conversion efficiency, grid integration, and overall system reliability. The article is structured to present an overview of the evolving landscape of power electronic systems, and the advantages of FCS-MPC. This paper provides a comprehensive analysis of the FCS-MPC control strategy applied to the single-phase five-level T-type topology. The study covers various aspects including the theoretical framework, hardware development, and experimental evaluation. It is obvious from the analysis that this inverter topology is reliable. Several redundant states make it fault-tolerant which helps in maintaining the output voltage at the same level even in the fault conditions. Additionally, the results show that the output load voltage is maintained at the same level irrespective of load change. Also, output load voltage has maintained the high-quality sinusoidal characteristics as the total harmonic distortion (THD) is very low. With all these features, this system is suitable within the framework of RES.

This paper introduces an effective Selective Harmonic Elimination (SHE) modulation technique in a five, seven, and nine-level cascaded H-bridge (CHB) multilevel inverter (MLI). Minimization of the harmonics and device counts is the basis for the ongoing research in the area of MLI. Reduced harmonics and hence the lower Total Harmonic Distortion (THD), improve the output power quality. SHE is a low-frequency modulation scheme to achieve this goal. SHE techniques are used to eliminate the distinct lower-order harmonics by determining the optimum switching angles. These angles are evaluated by solving the non-linear transcendental equations using any optimization technique. For this purpose, the Crystal Structure Algorithm (CryStAl) has been used in this paper. It is a metaheuristic, nature-inspired, and highly efficient optimization technique. CryStAl is a simple and parameter-free algorithm that doesn’t require the determination of any internal parameter during the optimization process. It is based on the concept of crystal structure formation by joining the basis and lattice point. This natural occurrence can be realized in crystalline minerals in their symmetrically organized components: ions, atoms, and molecules. The concept has been utilized to solve non-linear transcendental equations. SIMULINK/MATLAB environment has been used for the simulation. The simulation result shows that the crystal structure algorithm is very effective and excels the other metaheuristic algorithm. Hardware results validate the performance.

This study proposes a novel honey bee dancing (HBD) maximum power point tracking (MPPT) algorithm inspired by the foraging behavior of honey bees. When a bee finds nectar, it returns to the honeycomb and dances to inform others about the location of the nectar. Other bees then fly towards the location and gather the nectar. The proposed HBD algorithm uses five bees searching for the nectar who communicate with each other about the location and the quantity of nectar by dancing. Finally, the five bees found the location of the most nectar which is represented by the maximum power point. The proposed HBD algorithm applies to uniform irradiance condition (UIC) and partial shaded condition (PSC). It is then compared with the PV panel output power and load relationship (OPLR) algorithm and perturb and observe (P&O) algorithm. Experimental verification has been performed under both the UIC and PSC. At the UIC's irradiance level of 200 W/m², the PV module's output power for the proposed HBD algorithm, OPLR algorithm, and P&O algorithm are 120 W, 118 W, and 94.5 W, respectively, with efficiencies of 99 %, 97 %, and 78 %. Additionally, under the PSC with an irradiance level of 600 W/m², the PV module's output power for the proposed HBD algorithm, OPLR algorithm, and P&O algorithm are 218 W, 189.2 W, and 74.8 W, respectively, with efficiencies of 99 %, 86 %, and 34 %, and convergence times of 4.7 ms, 6.5 ms, and 6 ms, respectively. It is evident from the results that the solar MPPT performance of the proposed HBD algorithm is better than the OPLR algorithm and P&O algorithm. This method ingeniously combines the foraging behavior of bees with solar power generation to produce the maximum natural power. This approach does not require the development of photovoltaic (PV) panel specification data, complex calculations, and additional temperature meters and heliographs. It is highly efficient and has significant economic benefits.

This study proposes a novel maximum power point tracking (MPPT) control strategy for the solar photovoltaic power system (SPPS). The proposed system adopts two solar photovoltaic modules of 430 W, which are connected to a boost converter and an MPPT controller, since the traditional MPPT algorithm (such as perturbation and observation [P&O] algorithm) can hardly reach maximum power point (MPP) under low irradiance level and partial shading conditions (PSC), which leads to the low efficiency of the SPPS. The speed of light optical path difference measurement (SLOPDM) MPPT control strategy has been developed in this study to overcome this problem. The estimation of the optical path angle difference is used as the basis for the proposed control strategy. This is done by determining the relationship between the optical path angle difference, solar photovoltaic power impedance R_spv and load R_o, and then calculating the duty cycle corresponding to the MPP, which then drives the boost converter to capture the MPP. The experimental results verify the proposed system, which shows the efficiency comparison between the SLOPDM MPPT algorithm, solar angle and horizon (SAH) algorithm, and P&O algorithm under PSC and uniform irradiance conditions (UIC) at irradiance levels of 700 W/m² and 65 W/m². It is evident from the comparison that the efficiency of the SLOPDM MPPT algorithm is 99% under both conditions, which is higher than the SAH and P&O algorithms. The SLOPDM MPPT algorithm can precisely, rapidly, and stably be operated at MPP. The contribution of this study is that the proposed MPPT control strategy can help achieve the high−performance of SPPS without changing the hardware circuit design and requiring any additional solar power meter. This reduces the cost and the complexity of the system significantly.