A seven-level cascaded multilevel inverter based on simplified SVPWM method

The multilevel converters are extremely widespread alternatives within megawatt power level as well as medium voltage level applications due to their excellent execution than the typical two-level converters. The widely applied control strategies aimed at inverters are Sine Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM) strategies. In between these two PWM methods, the SVPWM strategy has excellent execution as compared to the SPWM strategy as a result of improved DC link voltage use as well as a decrease in Total Harmonic Distortion (THD) in output voltages. A traditional SVPWM strategy owns numerous weaknesses like computational complications in terms of identification of the reference voltage vector position, to identify sector, triangle and also it requires large memory for storing look up tables used for switching vectors. This paper presents, an innovative modified SVPWM strategy aimed at Cascaded H-Bridge Multilevel Inverter (CHBMLI). The novel modified SVPWM strategy has overwhelm the downsides of traditional SVPWM strategy. A seven-level CHBMLI is used for the implementation of this simplified SVPWM method to assess performance and as well to made comparison with the SPWM strategy. A MATLAB software is used for the simulation

5-level torque-hysteresis controller for DTC based IM drive

In the recent trade demand, the AC machines and drives are extensively utilized. Normally, the AC drives exploit with high efficacy as well as high performance. Among other things, one of the best control strategies is Direct torque control (DTC). For this article, the induction motor drive is projected very simple amended DTC scheme in accordance with the hysteresis controller. By the reason of its modest assembly & effective execution, DTC is used for AC as well as DC drive as associated to other monitoring structures. The presence of high ripple content in output torque for DTC scheme is only an obstacle. This article approaches extenuation of the ripples in torque by varying the predictable 5-level torque hysteresis controller used in DTC. The expansion of distinctive switching approach has been generated for chosen voltage vector. On the basis of ripple content simulation outcomes fulfilled in MATLAB/SIMULINK for hysteresis torque controller to minimized the ripples

Unipolar resistive switching in cobalt titanate thin films

We report giant resistive switching of an order of 104, long-time charge retention characteristics up to 104 s, non-overlapping SET and RESET voltages, ohmic in low resistance state (LRS) and space charge limited current (SCLC) mechanism in high resistance state (HRS) properties in polycrystalline perovskite Cobalt Titanate (CoTiO3 ~ CTO) thin films. Impedance spectroscopy study was carried out for both LRS and HRS states which illustrates that only bulk resistance changes after resistance switching, however, there is a small change (<10% which is in pF range) in the bulk capacitance value in both states. These results suggest that in LRS state current filaments break the capacitor in many small capacitors in a parallel configuration which in turn provides the same capacitance in both states even there was 90 degree changes in phase-angle and an order of change in the tangent loss.Comment: 7 pages, 4 figure

3D Digital Interactive Model of IIT Hyderabad Campus

This project aims to provide campus visitors an interactive tour of the beautiful IIT Hyderabad campus, using a user-friendly interface. In this project, different navigation technology is used to bring up relevant information queried by a user using visual analysis. The concept is a 3-Dimensional interactive campus model. Any visitor can browse, view, and interact with the immersive campus environment by different user actions. User can click on a building, zoom in or out which can help the user to find required information with 360-degree images, and videos. The proposed model can provide the real feel of campus from anywhere. In this project, different design tools and interaction methods were learned and used. Tools like Sketchup, Photoshop, Unity, Adobe XD, helped in designing the model

Behaviour of Quark and Strange Quark Matter for Higher Dimensional Bianchi Type -I Universe in f(R,T) Gravity

This research paper delves into a thorough examination of the behaviour exhibited by higher dimensional Bianchi Type-I universes, incorporating the presence of quark and strange quark matter within the framework of f(R,T) gravity. The solutions derived for the field equations encompass both exponential volumetric expansion and power law scenarios. Under the exponential expansion model, both the pressure (pq) and energy density (pq) associated with quark matter are initially finite at the inception of cosmic time, gradually diminishing to zero as time progresses towards infinity. Conversely, within the power law model, these parameters start off infinitely large at t = 0, subsequently decreasing to zero as time approaches infinity. Furthermore, an exploration of the physical and geometrical attributes of the model is conducted. Notably, in power law expansion models, the behaviour of strange quark matter mirrors that of quark matter concerning pressure (p) and energy density (ρ). But in exponential expansion model quark pressure and strange quark pressure behave differently. The bag constant emerges as a critical factor influencing the universe's expansion, with observations revealing that both pressure and energy density tend towards the bag constant at large time scales (t→∞). Specifically, the pressure p→ -BC and the energy density ρ→ BC as time approach infinity. The negative pressure sign denotes the universe's expansion during later epochs

Literature Survey On Standalone Pumping Station For Agriculture Purpose Using Solar PV

The concept of the project is to utilize the abundant solar energy available, harness it for effective work output. Here we are trying to use solar energy to run the centrifugal pump for lifting the water from the well. This can be utilized for different purpose like irrigation for agriculture & nurseries, etc. Here we are collecting all information about which kind of constraints required for planning of standalone pumping station for agriculture purpose. In this paper we are finding out which are power electronics applications in renewable energy sources. This document will help all researcher to start work on Solar PV’s, irrigation using renewable energy , as well as for finding the power electronics application in renewable energy sources. DOI: 10.17762/ijritcc2321-8169.15036

Formulation and evaluation of a face serum containing fenugreek extract

Background: Wrinkles on the face and aging of the skin are an undesirable effect of photodamage and ultraviolet radiation. Serum has a quick absorption and ability to penetrate deep layers of the skin, as well as a non-oily finish and a deep formula with a very high amount of active ingredients. Methods: In this study, we have formulated and evaluated a face serum containing combination of aqueous extract of fenugreek seed and lemon oil. Results: Facial serum was tested for its pH, physical appearance, viscosity, microbial testing, cyclic temperature test, etc. The results of the stability study show that there was no change in visual acuity, homogeneity. Conclusions: Serum containing Fenugreek extract have been able to cure bacterial infections and inflammations of facial skin, and other signs also moistens the skin without any side effects making skin soft, smooth and supple

Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure

BACKGROUND: Heart rate variability (HRV) is known to be impaired in patients with congestive heart failure (CHF). Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart. METHODS: Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet) of 29 subjects with CHF and 54 subjects with normal sinus rhythm. RESULTS: A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio) in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10(-5), 0.002, 3.5 × 10(-5 )and 0.0003, respectively). This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5). CONCLUSION: Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients