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This paper introduces a hybrid pulse width modulation (PWM) technique to enhance the efficiency and effectiveness of a grid-feeding superconducting magnetic energy storage (SMES)-based transformerless H6 inverter system. The system is designed to interface solar photovoltaic (PV) power with a low to medium-voltage grid. The presented hybrid PWM technique aims to suppress the total harmonic distortion (THD) of the output voltage of the H6 transformerless inverter. A new carrier signal and a new modulating signal based on fundamental sinusoidal and triangle waves are utilized to model the hybrid PWM technique. The proposed hybrid PWM technique is more efficient and has lower leakage current during energy conversion than traditional bipolar PWM, unipolar PWM, and numerous other well-known PWM techniques. The total system is simulated in the MATLAB/Simulink and PLECS environments to verify the feasibility of the proposed PWM strategy. A 1 kW laboratory-scale prototype based on an H6 transformerless inverter was also built and tested with the proposed PWM technique to prove the effectiveness of the whole system.

Transformerless grid-connected inverters are gaining popularity due to their high efficiency, compact design, and cost-effectiveness than transformer-based inverters. However, these inverters face significant challenges, particularly leakage current and limited voltage boost capability. This paper presents a novel solution to these issues through a five-level transformerless inverter (TLI) topology utilizing switched capacitors (SCs). The inverter utilizes seven insulated gate bipolar transistors (IGBTs), two diodes, and two SCs to achieve a five-level boosted output while ensuring low leakage current. Near-zero leakage current is enabled by maintaining a constant common mode voltage (CMV). Finite control set model predictive control (FCS-MPC), instead of traditional modulators, facilitates grid current tracking and reduced current harmonics. The use of only seven switches and two SCs results in increased efficiency and reduced losses. Comprehensive MATLAB/Simulink simulations and an experimental prototype validate the effectiveness of the proposed TLI for solar PV integration.

Pulsewidth modulation (PWM) techniques play a crucial role in determining the power quality of multilevel-inverter-based grid-tied solar photovoltaic (PV) fed systems. However, the existing PWM techniques suffer from the heat dissipation of the switches and power loss issues. In view of this concern, a new PWM technique is proposed to mitigate the junction temperature as well as the power loss of a cascaded H-bridge (CHB) inverter employed in a grid-tied solar PV system. Apart from the junction temperature of the power switch and power loss, different steady-state and dynamic responses of the CHB inverter are investigated using MATLAB/Simulink and PLECS software environments. Experimental results are also provided to support the simulation analysis.

Multilevel inverters (MLIs) have significantly improved the overall performance, dependability and efficiency of the renewable energy system. Moreover, these can be easily integrated with the superconducting magnetic energy storage (SMES) systems. Maintaining the power qualities of these MLIs is always marked as a major research concern which can be heavily impacted by the pulse width modulation (PWM) strategies. An improved voltage balancing discontinuous PWM (DPWM) scheme is suggested in this work for the single-phase grid-tied 5-level neutral point clamped (NPC) inverter, which can significantly mitigate the fluctuation of the dc-link capacitor voltages as well as the switching losses of the power IGBTs. The reduction in switching losses will give lower thermal stress to the power devices. The proposed DPWM scheme is compared with other existing DPWM schemes for proving its effectiveness. The simulation of the entire system is performed by using MATLAB Simulink and PLECS simulation platform. A lower scale prototype is also constructed in the laboratory.

This article introduces a new structure of switched-capacitor (SC)-based three-phase single-source multilevel inverter (MLI), which is designed to generate nine different output voltage (line-to-line) levels. A low-voltage grid-feeding photovoltaic system is the perfect use case for the inverter. The switching pattern is modeled in such a way that during voltage generation, the main dc source gets isolated, and voltage is supplied based on the SC units. As a result, the voltage of SC units is balanced automatically, and the SC units also provide boosted output voltage up to four times higher than the single-input dc source. Comparing this to other series-connected SC-based inverter topologies, such as flying capacitor and neutral-point-clamped inverters, no additional control complexity is mandatory. The system can be made modular to produce a higher level voltage output as well. The MLI topology, along with the whole system, is simulated in MATLAB/Simulink and PLECS simulation environment. A laboratory-scaled prototype was also built to justify the theoretical claim more boldly.

Conventional finite state predictive torque control (FS-PTC) suffers from increased computational complexity, torque ripple, and switching losses due to using all the available voltage vectors for prediction and estimation. This paper presents an enhanced FS-PTC algorithm for two-level voltage source inverter (VSI) driven induction motor drives (IMDs). The proposed method significantly reduces computational complexity by optimizing the voltage vector selection process. Based on motor operating conditions and stator current position, this reduces the number of evaluated vectors from eight to five. This optimization achieves a 24% reduction in execution time to 29.03 μs, compared to 36.06 μs for conventional FS-PTC, while maintaining excellent dynamic response. Additionally, the proposed approach reduces inverter switching losses and demonstrates improved performance metrics, including reduced torque ripple (2.35%), flux ripple (0.026%), and total harmonic distortion (7.06%) compared to the conventional method. Simulation results and experimental validation on a prototype confirm the effectiveness of the proposed strategy in enhancing computational efficiency and overall drive performance.

Total harmonic distortion (THD) and power loss have a substantial impact on the power quality of multilevel inverters (MLIs). They are both directly impacted by the switching method of pulse width modulation (PWM). Nevertheless, traditional PWM methods designed for MLIs have challenges that result in high THD and power loss problems. In view of these concerns, a modified level-shifted carrier-based PWM switching technique is presented in this work. The main goal of the proposed PWM technique is to reduce power losses and THD of neutral-point-clamped (NPC) inverter. The software platforms PLECS and MATLAB/Simulink are used thoroughly to model and simulate the whole system. Moreover, an experimental test at a reduced scale is conducted to verify the results of the simulation study, validating the feasibility of the suggested PWM technique.