Hysteresis Current Control Operation of Flying Capacitor Multilevel Inverter and Its Application in Shunt Compensation of Distribution Systems

Flying capacitor multilevel inverter (FCMLI) is a multiple voltage level inverter topology intended for high voltage and power operations with low distortion. It uses capacitors, called flying capacitors for clamping the voltage across the power semiconductor devices. In this paper, the implementation of a distribution static compensator (DSTATCOM) using an FCMLI is presented. A hysteresis current control technique for controlling the injected current by the FCMLI-based DSTATCOM is discussed. A new method for controlling the flying capacitor voltages is proposed which ensures that their voltages remain constant and at the same time maintain the desired current profile under the hysteresis current control operation. Simulation studies are performed using PSCAD/EMTDC to validate the efficacy of the control scheme and the FCMLI-based DSTATCOM

Static shunt and series compensations of an SMIB system using flying capacitor multilevel inverter

The flying capacitor multilevel inverter (FCMLI) is a multiple voltage level inverter topology intended for high-power and high-voltage operations at low distortion. It uses capacitors, called flying capacitors, to clamp the voltage across the power semiconductor devices. A method for controlling the FCMLI is proposed which ensures that the flying capacitor voltages remain nearly constant using the preferential charging and discharging of these capacitors. A static synchronous compensator (STATCOM) and a static synchronous series compensator (SSSC) based on five-level flying capacitor inverters are proposed. Control schemes for both the FACTS controllers are developed and verified in terms of voltage control, power flow control, and power oscillation damping when installed in a single-machine infinite bus (SMIB) system. Simulation studies are performed using PSCAD/EMTDC to validate the efficacy of the control scheme and the FCMLI-based flexible alternating current transmission system (FACTS) controllers

Torsional Interaction Studies on a Power System Compensated by SSSC and Fixed Capacitor

In this paper, a static synchronous series compensator (SSSC), along with a fixed capacitor, is used to avoid torsional mode instability in a series compensated transmission system. A 48-step harmonic neutralized inverter is used for the realization of the SSSC. The system under consideration is the IEEE first benchmark model on SSR analysis. The system stability is studied both through eigenvalue analysis and EMTDC/PSCAD simulation studies. It is shown that the combination of the SSSC and the fixed capacitor improves the synchronizing power coefficient. The presence of the fixed capacitor ensures increased damping of small signal oscillations. At higher levels of fixed capacitor compensation, a damping controller is required to stabilize the torsional modes of SSR

LLVM2GOTO: A translator from LLVM IR to CPROVER IR

There are more than 700 programming languages. The number of softwares is astronomical. It is highly important to verify whether the software meets it's specification and it is safe. However, there are very few stable software verification tools. Translating a source program into verification intermediate representation(VIR) is an overhead for software verification community. If we trans- late compiler intermediate representation into VIR, the overhead of translating source to VIR is reduced and software written in programming languages supported by the compiler can be verified. LLVM2GOTO uses LLVM IR as compiler IR and CPROVER's goto IR as VIR. In the current implementation we support variable declaration, load, store, arithmetic, bitwise, typecast, branch and switch instructions are supported by LLVM2GOTO.

Gender Dimensions on Farmers’ Preferences for Direct-Seeded Rice with Drum Seeder in India

This study measures the willingness of male and female farmers to pay for climate-smart technology in rice. Rice is the most important crop in India in terms of area, production, and consumption. It is also the biggest source of greenhouse gas emissions among all crops. Direct-seeded rice (DSR) with drum seeder, a climate-smart technology, requires less labor and water and is more climate friendly than transplanted rice; yet, its adoption is slow in India. The authors of this study carried out a discrete choice experiment with 666 farmers from the Palghar and Thane districts of Maharashtra to measure their willingness to pay for drum seeders—a key piece of equipment for adopting DSR. Both male and female farmers were surveyed to capture the heterogeneity in their valuation of the key attributes of drum seeders. Although both male and female farmers prefer cheaper drum seeders, the marginal valuation of different attributes of the drum seeder varies by the farmers’ gender. The authors also used the Women Empowerment in Agriculture Index (WEAI), developed by the International Food Policy Research Institute (IFPRI), to collect self-reported data on the role and say of women in agriculture. The respective gender roles in the family and on the farm seem to explain some of this difference. Men have a greater say over how the family spends the cash. Accordingly, men tend to have a higher willingness to pay for attributes that increase income (increase in yield) or reduce cash costs (reduction in the seed rate). Women contribute a large share of the labor for transplanting rice, much of which is unpaid work on family farms. Not surprisingly, therefore, women seem to value labor saving significantly more than their male counterparts. Further, the WEAI data show that although men in the family have more say, women do have an influence on decisions regarding crop production and the adoption of new technologies, to an extent. Therefore, to enhance the adoption of drum seeders, the product designers and extension workers should also target women

GNL: GeoFencing Based Smart Outdoor Navigation and Localization

Navigation is a technique used by humans to construct a plan to help them travel within a place using instruments or maps. Navigation in the modern age is done using various electronic systems which provide a real-time map of the place and the step-by-step directions to the desired destination. The technology widely used today is GPS i.e. Global Positioning System. Outdoor navigation using Google maps, here maps or safari is a common go-to for the users but the problem is the map provided by these companies just has an overview of the place and not the detailed information. The GNL approach which authors have used in this paper focuses on the navigation and localization of the gated environment so that the person living and visiting the area will get familiar with the area and understand the area very well. The web app that authors have designed can be used for the College Campus, Fairs, open museums, etc. Comparative analysis of the web app-based approach is done with an existing one. The Presented approach will not only help you in navigation but also provide you with information about the POI (Point of Interests) of those visiting places. The Geofence mechanism will help users to navigate and get information about the area. The aim is to give the user the maximum information about the place with secured transfer of information and better localization. The authors have tested the approach on the real testbed in the gated society and it provides good results for what it promises

Sperm mitochondrial mutations as a cause of low sperm motility

We report the unique case of a 28-year-old man who, in spite of having a varicocele and a sperm concentration of 5 million/mL, of which 10% were motile and 20% had normal forms (oligoasthenoteratozoospermia [OAT]), was fertile. This was confirmed by paternity testing using 16 autosomal and 6 Y-chromosomal short tandem repeat (STR) loci. An analysis of mitochondrial genes that included cytochrome oxidase I (COI), cytochrome oxidase II (COII), adenosine triphosphate synthase6 (ATPase6), ATPase8, transfer ribonucleic acid (tRNA) serine I, tRNA lysine, and NADH dehydrogenase3 (ND3) revealed, for the first time, 9 missense and 27 silent mutations in the sperm's mitochondrial DNA (mtDNA) but not in the DNA from the blood cells. There was a 2-nucleotide deletion in the mitochondrial COII genes, introducing a stop codon, which might be responsible for low sperm motility

The feasibility of task-sharing the identification, emergency treatment, and referral for women with pre-eclampsia by community health workers in India

Background: Hypertensive disorders are the second highest direct obstetric cause of maternal death after haemorrhage, accounting for 14% of maternal deaths globally. Pregnancy hypertension contributes to maternal deaths, particularly in low- and middle-income countries, due to a scarcity of doctors providing evidence-based emergency obstetric care. Task-sharing some obstetric responsibilities may help to reduce the mortality rates. This study was conducted to assess acceptability by the community and other healthcare providers, for task-sharing by community health workers (CHW) in the identification and initial care in hypertensive disorders in pregnancy.Methods: This study was conducted in two districts of Karnataka state in south India. A total of 14 focus group discussions were convened with various community representatives: women of reproductive age (N = 6), male decision-makers (N = 2), female decision-makers (N = 3), and community leaders (N = 3). One-to-one interviews were held with medical officers (N = 2), private healthcare OBGYN specialists (N = 2), senior health administrators (N = 2), Taluka (county) health officers (N = 2), and obstetricians (N = 4). All data collection was facilitated by local researchers familiar with the setting and language. Data were subsequently transcribed, translated and analysed thematically using NVivo 10 software.Results: There was strong community support for home visits by CHW to measure the blood pressure of pregnant women; however, respondents were concerned about their knowledge, training and effectiveness. The treatment with oral antihypertensive agents and magnesium sulphate in emergencies was accepted by community representatives but medical practitioners and health administrators had reservations, and insisted on emergency transport to a higher facility. The most important barriers for task-sharing were concerns regarding insufficient training, limited availability of medications, the questionable validity of blood pressure devices, and the ability of CHW to correctly diagnose and intervene in cases of hypertensive disorders of pregnancy.Conclusion: Task-sharing to community-based health workers has potential to facilitate early diagnosis of the hypertensive disorders of pregnancy and assist in the provision of emergency care. We identified some facilitators and barriers for successful task-sharing of emergency obstetric care aimed at reducing mortality and morbidity due to hypertensive disorders of pregnancy