A novel control strategy of three-phase, four-wire UPQC for power quality improvement

The current paper presents a novel control strategy of a three-phase, four-wire Unified Power Quality (UPQC) to improve power quality. The UPQC is realized by the integration of series and shunt active power filters (APF) sharing a common dc bus capacitor. The realization of shunt APF is carried out using a three-phase, four-leg Voltage Source Inverter (VSI), and the series APF is realized using a three-phase, three-leg VSI. To extract the fundamental source voltages as reference signals for series APF, a zero-crossing detector and sample-and-hold circuits are used. For the control of shunt APF, a simple scheme based on the real component of fundamental load current (I CosΦ) with reduced numbers of current sensors is applied. The performance of the applied control algorithm is evaluated in terms of power-factor correction, source neutral current mitigation, load balancing, and mitigation of voltage and current harmonics in a three-phase, four-wire distribution system for different combinations of linear and non-linear loads. The reference signals and sensed signals are used in a hysteresis controller to generate switching signals for shunt and series APFs. In this proposed UPQC control scheme, the current/voltage control is applied to the fundamental supply currents/voltages instead of fast-changing APF currents/voltages, thus reducing the computational delay and the required sensors. MATLAB/Simulink-based simulations that support the functionality of the UPQC are obtained

Control strategy for selective compensation of power quality problems through three-phase four-wire UPQC

This paper presents a novel control strategy for selective compensation of power quality (PQ) problems, depending upon the limited rating of voltage source inverters (VSIs), through a unified power quality conditioner (UPQC) in a three-phase four-wire distribution system. The UPQC is realized by the integration of series and shunt active power filters (APFs) sharing a common dc bus capacitor. The shunt APF is realized using a three-phase, four-leg voltage source inverter (VSI), while a three-leg VSI is employed for the series APF of the three-phase four-wire UPQC. The proposed control scheme for the shunt APF, decomposes the load current into harmonic components generated by consumer and distorted utility. In addition to this, the positive and negative sequence fundamental frequency active components, the reactive components and harmonic components of load currents are decomposed in synchronous reference frame (SRF). The control scheme of the shunt APF performs with priority based schemes, which respects the limited rating of the VSI. For voltage harmonic mitigation, a control scheme based on SRF theory is employed for the series APF of the UPQC. The performance of the proposed control scheme of the UPQC is validated through simulations using MATLAB software with its Simulink and Power System Block set toolboxes

New control algorithms for three-phase four-wire unified power quality conditioner — a simulation study

n this paper, some new control algorithms are proposed for three-phase four-wire Unified Power Quality Conditioner. These control algorithms are based on the combination of Unit Vector Template Generation (UVTG) with Power Balance Theory (PBT), single phase d-q theory, Synchronous Current Detection (CSD) technique, and I CosΦ theory. The performance of each control algorithm of UPQC is evaluated in terms of power factor correction, load balancing and source neutral current mitigation, and voltage and current harmonic mitigation. The performance of proposed control algorithms are compared with synchronous reference frame (SRF) based control algorithm. In each proposed control scheme of the three-phase four-wire UPQC, the current/voltage control is applied over the fundamental supply currents/ load voltages instead of fast changing APFs currents/voltages, thereby reducing the effects of computational delay. Moreover, the load neutral or shuntAPF neutral currents are not sensed hence the required current sensors are reduced

Gowda et al (2014). Development and assessment of Pig Feed Formulator 264 Research Article

Pig production in India have come a long way from traditional open grazing-based pig production to concentrate feed based commercial production in certain pockets of India. There has been limited information about feeding system, production performance, needs and constraints of these farms due to their scattered spatial distribution. The present study was designed to study these issues and develop a need based pig feed formulation software. A sample of 100 commercial pig farmers across five states of India was interviewed to assess the needs and performance of commercial pig farms. Based on the need, software called "Pig Feed Formulator (PFF)" was developed to assist the pig farmers in on-farm feed formulation using locally available feed ingredients. PFF was administered among 90 respondents including academicians, field veterinarians and commercial pig farmers (30 respondents from each group) in two states to assess the perceived utility of PFF. The study revealed that majority of commercial pig farmers were not aware of balanced feeding despite 83% of literacy. Average body weight of fatteners at 6 months and litter size was found to be 37% and 29.72% less than the attainable production. Even with good digital literacy most of the commercial pig farmers were not aware of feed formulation software but, majority of them were interested to use it. Post development assessment showed that utility index of the software was found to be very high (UI = 0.76) with maximum willingness to pay (UII = 0.9). The average price quoted on PFF was rupees 1,188

Nonlinear modelling of sheep and goat populations in India

The objective of this paper was to study the trend in population of sheep and goat populations during 1951 to 2012 in India. The data were compiled from various issues of BAHS (Basic Animal Husbandry Statistics) for the period 1951 to 2012. Different nonlinear growth models such as Parabolic/Sikka, Brody, Brody modified, Wood, Logistic and Gompertz models were fitted to the census data of sheep and goat population. The goodness of fit of the models was tested by Coefficient of determination (R2), Adjusted coefficient of determination (R2), Mean Square Error (MSE), Mean Absolute Error (MAE) and Akaike Information Criteria (AIC). The populations of sheep and goat in India during the year 1951 were 39.10 million and 47.20 million numbers respectively and reached 135.17 million and 65.06 million respectively in the year 2012. Based on the various measures of goodness of fit we observed that the Parabolic/Sikka model was the best fitted model for studying the pattern in the populations of sheep and goat in India. This model has been used to project the sheep and goat population in India during 2020, 2025 and 2030. If the present pattern of growth continued in near future then the projected sheep population will be 102.37 million numbers whereas goat population will be 151.57 million numbers in the year 2030. The present study will provide the pattern in which the changes have been observed in sheep and goat populations in India during 1951 to 2012

Performance of Chilli (Capsicum annuum L.) hybrids for yield and quality traits

Twenty-eight F1 combinations of chilli (Capsicum annuum L.) obtained from half-diallel cross along with eight diverse parents were evaluated in a field study to elucidate the information on the extent of mean performance of various horticultural traits. The analysis revealed that all the genotypes possessed wide spectrum of variability and showed significant differences for parents and hybrids for the traits studied. For parents UHF CHI 13 (216.20), UHF CHI 15 (193.80), UHF CHI 5 (139.00) and for hybrids H1 (182.60), H9 (181.40) and H7 (172.80) hold highest fruit count per plant. The parents UHF CHI 5 (1047.13 g), UHF CHI 15 (949.62 g) and UHF CHI 7 (912.61 g) and cross combinations H17 (1535.10 g), H8 (1320.00), H6 (1229.76) and H18 (967.60) recorded the high ripe fruit yield per plant. As for earliness, parents UHF CHI 5 (43.33), UHF CHI 11 (45.00), UHF CHI 7 (45.33) and hybrids H27 (42.67), H26 (43.00) and UH28 (43.00) took minimum days for flowering. For pungency UHF CHI 12 (0.28 %), UHF CHI 13 (0.26 %), DKC-8 (0.24 %) and H23 (0.33 %), H5 (0.31 %), H26 (0.26 %) recorded high capsaicin content

Integration of gene-based markers in a pearl millet genetic map for identification of candidate genes underlying drought tolerance QTLs

BACKGROUND: Identification of genes underlying drought tolerance (DT) quantitative trait loci (QTLs) will facilitate understanding of molecular mechanisms of drought tolerance, and also will accelerate genetic improvement of pearl millet through marker-assisted selection. We report a map based on genes with assigned functional roles in plant adaptation to drought and other abiotic stresses and demonstrate its use in identifying candidate genes underlying a major DT-QTL. RESULTS: Seventy five single nucleotide polymorphism (SNP) and conserved intron spanning primer (CISP) markers were developed from available expressed sequence tags (ESTs) using four genotypes, H 77/833-2, PRLT 2/89-33, ICMR 01029 and ICMR 01004, representing parents of two mapping populations. A total of 228 SNPs were obtained from 30.5 kb sequenced region resulting in a SNP frequency of 1/134 bp. The positions of major pearl millet linkage group (LG) 2 DT-QTLs (reported from crosses H 77/833-2 × PRLT 2/89-33 and 841B × 863B) were added to the present consensus function map which identified 18 genes, coding for PSI reaction center subunit III, PHYC, actin, alanine glyoxylate aminotransferase, uridylate kinase, acyl-CoA oxidase, dipeptidyl peptidase IV, MADS-box, serine/threonine protein kinase, ubiquitin conjugating enzyme, zinc finger C- × 8-C × 5-C × 3-H type, Hd3, acetyl CoA carboxylase, chlorophyll a/b binding protein, photolyase, protein phosphatase1 regulatory subunit SDS22 and two hypothetical proteins, co-mapping in this DT-QTL interval. Many of these candidate genes were found to have significant association with QTLs of grain yield, flowering time and leaf rolling under drought stress conditions. CONCLUSIONS: We have exploited available pearl millet EST sequences to generate a mapped resource of seventy five new gene-based markers for pearl millet and demonstrated its use in identifying candidate genes underlying a major DT-QTL in this species. The reported gene-based markers represent an important resource for identification of candidate genes for other mapped abiotic stress QTLs in pearl millet. They also provide a resource for initiating association studies using candidate genes and also for comparing the structure and function of distantly related plant genomes such as other Poaceae members

Some reproductive parameters of Zanskari mares reared in an organized farm under tropical climate

The present study was undertaken to record the data on duration of estrus, estrus cycle length, size of the follicle at ovulation, period of gestation and estrus after foaling (foal heat) in respect of Zanskari mares for 4 consecutive breeding seasons (2010–2014). The mares were closely monitored with transrectal ultrasonography for their follicle size variation and to determine size of the follicle at ovulation. The mares were inseminated with frozen thawed semen from Zanskari stallions. This is the first time ever that Zanskari stallion semen was cryopreserved successfully and viable foals were produced by using frozen semen via artificial insemination. The reproductive parameters of the mares of Zanskari breed in India are poorly investigated and thus no reports are available on reproductive characteristics of Zanskari breed till today in the literature. Our results can be useful as a ready reference for some of the reproductive characteristics and traits of Zanskari breed as well as indigenous horses reared under tropical region. The reproductive parameters analysed in the present study are fitting within the characteristics of the other Indian horse breeds reared under this region and the differences may be caused by breed effect and other environmental factors

Soft X-ray and FUV observations of Nova Her 2021 (V1674 Her) with AstroSat

Nova Her 2021 or V1674 Her was one of the fastest novae to be observed so far. We report here the results from our timing and spectral studies of the source observed at multiple epochs with AstroSat. We report the detection of a periodicity in the source in soft X-rays at a period of 501.4–501.5 s which was detected with high significance after the peak of the super-soft phase, but was not detected in the far ultraviolet (FUV) band of AstroSat. The shape of the phase-folded X-ray light curves has varied significantly as the nova evolved. The phase-resolved spectral studies reveal the likely presence of various absorption features in the soft X-ray band of 0.5–2 keV, and suggest that the optical depth of these absorption features may be marginally dependent on the pulse phase. Strong emission lines from Si, N, and O are detected in the FUV, and their strength declined continuously as the nova evolved and went through a bright X-ray state.Fil: Bhargava, Yash. No especifíca;Fil: Dewangan, Gulab Chand. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Anupama, G. C.. No especifíca;Fil: Kamath, U. S.. No especifíca;Fil: Sonith, L. S.. No especifíca;Fil: Pal Singh, Kulinder. ndian Institute of Science Education and Research Mohali; IndiaFil: Drake, J. J.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Beardmore, A. University of Leicester; Reino UnidoFil: Luna, Gerardo Juan Manuel. Secretaria de Investigacion ; Universidad Nacional de Hurlingham; . Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Orio, M.. Istituto Nazionale di Astrofisica; ItaliaFil: Page, K. L.. University of Leicester; Reino Unid