Harmonics and Phasor Estimation for a Distorted Power System Signal

The controlling, operating and monitoring of electric devices has been possible because of the knowledge of power system parameters. The relay functionality in power systems is influenced by the two vital power system parameters which are frequency and harmonics. Hence in power systems, phasor estimation is of utmost importance. These computations not only facilitate realtime state estimation, but also improve protection schemes. However, in the presence of power frequency deviation, the phasor undergoes rotation in the complex plane. Interconnection of power grids and distributed generation systems becomes difficult because of this phenomenon. Hence, in this report different algorithms are studied and implemented for the estimation of phasor. The parameters estimated are limited to voltage amplitude and phase, change of frequency and rate of change of frequency. In this thesis, Singular Value Decomposition (SVD) technique and Recursive Least Square (RLS) algorithms are used to estimate the amplitude and phase for different harmonics present in a distorted power system signal. Simple DFT algorithm is used to estimate the phasor variation, change of frequency and rate of change of frequency when deviated from the nominal frequency

Light weight aircraft weighing system

One important parameter in the calculation of the performance of an aircraft is its weight. There are two methods commonly used for aircraft weighing. In one method, platform is used under each tier. In this method four load cells are located in the four corners of a13; platform and signals of each load cell are brought out through a connector on one side of the platform. Ramps leading up to the platform are used to roll the aircraft on and off the platform. In the second method load cell is placed on a jack under each axle. Aircraft is then jacked13; up off the ground to put its full weight on the load cells. The load cell outputs are processed and the sum of the three processed outputs gives the weight of the aircraft. This document describes an Aircraft Weighing System having a range of 0-1000kg. The system has an accuracy of +0.1% of the full range and a resolution of +10 gms. The system consists of three weighing platforms, each of them incorporating four load cells fitted in a frame work. Two of the platforms have a range of13; 0-300 kg and the third has a range of 0-60 kg. The system was developed for the Flight Research Group of the division, during the fabrication and operation of the Light Canard Research Aircraft (LCRA). The front wheel of the aircraft is placed on the platform with the range and platforms with larger ranges are used for the two rear wheels

Stress measurement in the steel rolling mill

Imported Straight Bevel Gear originally fitted in the13; Merchant-Mill was replaced by indigenously made straight bevel gear in Steel Rolling Mill at TISCO, Jamshedpur. The replaced gears were developing crack originating at the fillet region extending towards the centre with in a short period of two to three months operation,causing large production loss. It was suspected that certain unpredicted peak loads exceeding designed limits might be present during Mill operation. To make a quantitative assesment of the peak load, the measurement of tooth load and torque in the driving axle was undertaken. For this purpose, a six channel FM-FM telemetry system was developed at N A L for measuring gear stresses using foil strain gauges.In the Strip Rolling Mill, the thickness of the sheet was depending on the roller load. A load monitoring system consisting of two load cells of 100 tonnes range each and a digital load indicator was developed at N A L for monitoring the roller bearing load for better thickness control

Unlocking the synergetic potential of cobalt iron phosphate and multiwalled carbon nanotube composites towards supercapacitor application

To date, bimetallic phosphates have not been much explored in supercapacitor applications. Interestingly, these materials hold significant potential for energy storage due to the existence of multiple oxidation states and the presence of numerous phosphorus atoms, each contributing to a substantial number of electron clouds. Present research emphasises the electrochemical performance of composite electrodes consisting of multiwalled carbon nanotubes (MWCNTs) and cobalt iron phosphate (Co3Fe4(PO4)6). These electrodes have demonstrated exceptional performance and achieved a specific capacity of 3320 C g−1 (3688 F g−1) at a scan rate of 5 mV s−1 maintaining 87% stability even after 5000 cyclic voltammetry (CV) cycles. The electrochemical active surface area (ECSA) was estimated to be 700 cm2 for Co3Fe4(PO4)6 and 1625 cm2 for MWCNTs/Co3Fe4(PO4)6 composites. Additionally, the designed and tested large-area (10 × 4 cm2) liquid-configured symmetric device exhibited an impressive energy density (ED) of 52.3 W h kg−1 and power density (PD) of 3.5 kW kg−1. The fabricated device showed outstanding stability with a 98% capacity retention after 5000 cycles, reflecting the remarkable durability of the designed system. To illustrate its real-world applicability, the constructed device underwent a 10 s charging to power a DC fan for 110 s.</p

9.Relationship of indirect diagnostic tests, haematological parameters and milk components with subclinical mastitis in dairy cows

Not AvailableThe study aimed to understand the relationship of California Mastitis Test (CMT) score and other indirect diagnostic tests [differential electrical conductivity (DEC) and absolute EC] with milk Somatic Cell Count (SCC) to improve the diagnosis of subclinical mastitis (SCM) in lactating Deoni (N=27) and HF crossbred (N=32) cows. Cows with milk SCC of ?200?103 cells/ml were considered as SCM, while cows without any abnormality in milk or udder parenchyma, systemic signs and milk SCC of ?200?103 were considered as healthy. It is observed that healthy and SCM affected Deoni cows had lesser milk SCC than HF crossbred cows. We found that breed had significant (p<0.001) effects on blood hemoglobin and packed cell volume (PCV) level but Red Blood Cell (RBC) counts, Total Leucocytes Count (TLC) and Differential Leucocytes Count (DLC) were not altered by breed and udder health status of Deoni and HF crossbred cows. Higher trend of fat: protein ratio was observed in SCM affected than healthy cows. In this study, the relationship of CMT score with SCC has been established and the finding will be useful for diagnosis of SCM using indirect diagnostic methods in Indian dairy cattle

A facile and single pot strategy for the synthesis of novel naphthyridine derivatives under microwave irradiation conditions using ZnCl2 as catalyst, evaluation of AChE inhibitory activity, and molecular modeling studies

A series of novel naphthyridine derivatives 3 and 4 was prepared from substituted pyridine 2 and ketones using ZnCl2 as catalyst under microwave irradiation conditions. All the compounds were evaluated for AChE inhibitory activity and promising compounds 3d, 3e, 4b, and 4g was identified. Representative compounds 3d and 3e were found to show insignificant THLE-2 liver cell viability/toxicity. The binding mode between X-ray crystal structure of human AChE and compounds was studied using molecular docking method and fitness scores were found to be in good correlation with the activity data.CUSATMed Chem Res (2012) 21:1785–1795 DOI 10.1007/s00044-011-9695-