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In this paper, one simplified transfer function based and detailed mathematical modelling based closed loop structure of a BLDC drive has been established with various combinations of classical controllers. Typical PWM operated control strategy is incorporated in the conventional two-level inverter (VSI) fed permanent magnet (BLDC) motor to minimize the torque ripple. To form a typical closed-loop structure, it comprises of two control loops for better speed and torque control implementation in certain purposes. The system is examined in MATLAB Simulink with various combinations of the classical and fuzzy controllers. Though the inner current loop should be ahead in procedureassociatedwith the external speed loop, thus PI controllers are mostlychosen as a current controller. These controller gains are enhancedby means of two optimization methods of Particle swarm optimization and Genetic algorithm to get a betterresponse by eliminating steady-state error, max peak overshoot and decreasing the rising time, peak time, of the projected BLDC motor drive.

This BLDC motor is in high demand nowadays due to its high efficiency and other significant features. As there is no use of brushes, this type of motor is having many advantages like high torque to inertia ratio, high speed, and power density and low cost compared to conventional brushed motors. To achieve more improved motor, it is important to analyse the BLDC motor's performance by varying different types of motor parameters. One of the important parameters is the sensor position or the sensor angle at which the sensor will be placed with the axis of the motor. Sensors sens the rotor position of the motor and send this information to the controller and accordingly, the switching sequence of Inverter is being decided. In this paper how varying the sensor position angle effects on the overall performance of BLDC motor in its no-load condition will be discussed.

Due to very intermittent properties of lightning strike and also hazards involved within it, very limited research has been conducted in Lightning energy harnessing area worldwide. However, the lightning causing clouds have very high charge density. So, an experimental study in numerical computational environment has been experimented for measuring the response characteristics of lightning spark to store the energy by real time environmental data collected from various meteorological center. The single stage two level spark generator circuit has been used to simulate the presented system. Also, this paper presents an analytical and experimental response of five level inverter integrated with supercapacitor to store lightning energy within supercapacitor and to convert it into AC voltage for various loads. Through this presented paper an imitated response has been shown of PMSM and Grid Load connected with storage and conversion system.

The analytical and simulation based experiment in this presented paper shows a comparative study between the two-level inverter and five-level inverter to convert supercapacitive energy for PMSM Load. Sometimes dependent numerical models are used to measure the voltage and current response for those inverters in MATLAB Simulink based environment. In this study, Supercapacitive sources are used as input sources to analyze the response of multilevel inverters to integrate with the supercapacitive energy storage devices in any system. The PMSM loads are used to compute the time response in the simulation environment. A comparative study has been made of two different level types of inverters with the simulation results. Two basic types of the inverter are discussed in the study with reference to their electrical behavior. It is also simulated that multilevel inverter can convert stored energy within supercapacitor, which can be integrated to store energy in the renewable energy system.

We report second harmonic generation (SHG) with a flat wide bandwidth accompanied by good conversion efficiency in an isotropic semiconductor slab with a parabolic upper profile. The concept of SHG conversion stands on the principle of total internal reflection quasi-phase matching (TIR-QPM). A simulation has been performed using GaAs as the non-linear material, in the fundamental wavelength range of 6.8–10.8 μm, considering ppp polarization configuration. Optimized simulation results, after considering reflection and absorption losses, show a flatter bandwidth of 642 nm in a 36 mm slab in comparison to a dipped 3 dB bandwidth of 770 nm in an elliptically profiled isotropic slab as well as a steeper bandwidth of 187 nm in a tapered isotropic slab. The present simulation shows an acceptable conversion efficiency of 1.105%.

We analytically describe quasi-phase matched second-harmonic generation in the mid-IR region in a parallel isotropic semiconductor slab made of Zinc Telluride (ZnTe) and Cadmium Telluride (CdTe) using total internal reflection quasi phase matching technique. The simulated results indicate conversion efficiencies of 4.08% (centered at 8.495 -mm-long slab of ZnTe and CdTe respectively. The losses due to surface roughness, Goos-Hanchen shift and absorption of the slab have been considered in the analysis. The effect of variation in the angle of incidence has been studied for both the materials. Keywords-second-harmonic generation, total internal reflection, quasi phase matching, isotropic, zinc telluride, cadmium telluride.

The simulated model calculates the phase matching angle for a parallel isotropic slab made of Zinc Telluride (ZnTe), Cadmium Telluride (CdTe), Gallium Arsenide (GaAs) wavelength of 10.6 μm by determining the wave-vector mismatch. The model also generates the status of fulfillment of Total Internal Reflection (TIR) inside the semiconductor slab. The simulated results indicate phase matching angle of 0.9034 rad for a slab thickness of 800 μm in case of ZnTe and 0.5457 rad for CdTe taking the slab thickness as 500 μm. The phase matching angle for ZnSe is 1.481 rad and that of GaAs is materials. For all the cases, the TIR condition is found satisfying. KeywordsWave-vector mismatch, Phase matching, Quasi phase matching, Isotropic, Total Internal Reflection Quasi Phase