In this research, a new single-phase direct AC-to-AC converter, operating in buck and boost mode, with a bipolar voltage gain, is proposed. The operation is accomplished through high frequency direct and indirect PWM control of a single switch with low voltage stresses. This reduces, not only the control effort, but also the switching losses. The low voltage stresses across the high frequency switches, reduce the dv/dt problem significantly without any loss and bulky voltage snubber arrangement. The operation, in its all-operating modes, has a low inductor ripple current and switching current. The proposed converter may be employed as an AC voltage restorer in a power distribution system to cope with the voltage sag and swell issues. The detailed analysis of the proposed converter is carried out in order to compare its performance with the existing converters. The simulation results obtained using the MATLAB/Simulink environment are verified through experimental results.

Induction heating (IH) is an environmentally friendly solution for heating and melting processes. The required high-frequency magnetic field is accomplished through frequency controllers. Direct frequency controllers (DFC) are preferred to dual converters as they have low conversion losses, compact size, and simple circuit arrangement due to low component count. Numerous frequency controllers with complex switching algorithms are employed in the induction heating process. They have a complicated circuit arrangement, and complex control as their switching sequences have to synchronize with source voltage that requires the zero-crossing detection of the input voltage. They also have a shoot-through problem and poor power quality. Therefore, this research proposes a novel frequency controller with a low count of six controlled switching devices without a zero-crossing detector (ZCD) having a simple control arrangement. The required switching signals are simply generated by using any pulse-width-modulated (PWM) generator. The performance of the proposed topology is verified through simulation results obtained using the MATLAB/Simulink environment and experimental setup.

Trending electric vehicles with different battery technologies need universally compatible and fast chargers. Present semiconductor technology is not suitable for designing high-power-rating converters. The increasing demand for high-capacity electric vehicle chargers requires efficient and optimum advanced material technology. This research presents next-generation material-based smart ultra-fast electric vehicle charging infrastructure for upcoming high-capacity EV batteries. The designed level 4 charger will be helpful for charging future heavy-duty electric vehicles with battery voltages of up to 2000 V. The designed infrastructure will be helpful for charging both EVs and heavy-duty electric trucks with a wide range of power levels. Wireless sensor-based smart systems monitor and control the overall charging infrastructure. The detailed design analysis of the proposed charger using the Simscape physical modeling tool is discussed using mathematical equations.

Gas insulated transmission lines (GILs) are being used in electrical systems regarding power transmission and substation interconnection. However, operational complexities of conventional schemes, such as structural rigidity, corrosion protection, gas leakage in case of seismic vibrations, larger bending radius and jointing complexities which restrain their application perspectives, could be curtailed by developing a flexible GIL. In this research paper, a new pliable scheme of gas insulated transmission line is proposed. Further, COMSOL Multiphysics^® (version 5.1, COMSOL Inc., Stockholm, Sweden) based electrostatic assay and practically performed high voltage tests-based dielectric analysis is performed for the proposed scheme. Electrostatic appraisal is comprised of field utilization based electrostatic stress analysis. In addition, dimensional optimization of pliable GIL regarding enclosure and pitch sizes in relation to electrostatic stresses and field utilization is also performed. Regarding dielectric perusal, experimental setup has been developed for standard lightning impulse and disruptive discharge tests in order to investigate the synergistic dielectric characteristics of proposed flexible post insulators for pliable GIL. Experimental and simulation appraisal unveil that the proposed scheme exhibits almost analogous electrostatic and dielectric behavior in comparison to the conventional GIL scheme and could simplify the operational intricacies associated with conventional scheme. The proposed modifications could eliminate the requirement of trench development, corrosion protection and acceleration dampers, along with a significant reduction in required land area at bends, due to a smaller bending radius which will ultimately result in substantial cost reduction.

The implementation of stranded conductors in flexible gas-insulated transmission lines (FGILs) requires field intensity minimization as well as field irregularity suppression in order to avoid dielectric breakdown. Moreover, the interdependence of enclosure and conductor sizes of FGILs regarding electrostatic aspects necessitate critical consideration of their dimensional specifications. In this research, geometric and electrostatic field optimization for FGILs regarding stranded conductors is performed. In addition, the effect of conductor irregularity on field dispersion is analyzed, and a semiconducting film (SCF)-coated stranded conductor is proposed as a potential candidate for FGILs. Considering the performed optimized design, an 11 kV scaled-down model of a 132-kV FGIL was also fabricated in order to practically analyze its electrostatic and dielectric performances regarding simple and SCF-coated stranded conductors. Simulation and experimental investigations revealed that the SCF-coated stranded conductor significantly minimized the field irregularity of the FGIL along with improving in its dielectric breakdown characteristics.

Land shortage in metropolitan vicinities entails subsurface implementation of power transmission lines (PTLs) which demand structural flexibility, as well as substantial load bearing capability. Thus, development of a flexible gas insulated transmission line (FGIL) necessitates its strength degradation analysis, regarding the synergistic effect of aging and mechanical loadings. Moreover, correlation of conductor and enclosure dimensions of FGIL apropos field distribution, requires careful consideration regarding their dimensional specifications. In this research, a comprehensive electro-mechanical design is performed for the proposed flexible-thermoplastic-enclosure of a 132 kV FGIL by considering the synergistic impact of time and temperature-based aging, along with the effect of external and internal loadings, such as dead load, live load and internal gas pressure. Additionally, a recursive design algorithm for the proposed scheme regarding electro-mechanical aspects, along with aging perspectives is developed. Comparative analysis of proposed and conventional schemes regarding electro-mechanical and aging aspects revealed that the proposed enclosure exhibits the required structural strength, as well as flexibility for trenchless subsurface application of FGILs in metropolitan areas.