Control strategies for seamless transfer between the grid-connected and islanded modes of a microgrid system

Design of control strategies for Distributed generation systems is very important to achieve smoother transition between the grid connected and islanding modes of operation. The transition between these two modes of operation should be seamless, without any severe transients during the changeover. In this paper, two different control strategies namely inverter output current control and indirect grid current control for the seamless transfer between the modes of operation has been explored for the suitability. The design and analysis of the cascaded control loops based on Proportional Integral (PI) controller has been dealt in detail for both inverter output current control and indirect grid current control strategy. Control parameters are designed using the control system toolbox in MATLAB. A 10kW grid connected microgrid system has been designed and simulated in MATLAB/Simulink and the results are presented under grid connected operation, islanding operation and the transition between the modes considering fault condition in the grid side. The simulation studies are carried out using both the control strategies and the results are presented to validate the design methodology

A Novel Method to Develop High Fidelity Laser Sensor Simulation Model for Evaluation of Air to Ground Weapon Algorithms of Combat Aircraft

Successful release of any air to ground weapon from a combat aircraft is determined based on the positional parameters received from the sensors and the mission cues. Laser designated pod is one of the most sought weapon sensor, which gives the accurate data for Air to Ground weapon aiming. Laser designated pod being hardware intensive system, works with real world environment, it increases the development and integration effort towards finalising the weapon aiming algorithms and also pilot vehicle interface requirements. A novel method using mathematical models and the atmospheric error models is proposed to develop a high fidelity laser designated pod simulation model for functional and performance evaluation of weapon algorithms. The factors affecting the weapon trajectory computations are also considered in the sensor model outputs. The sensor model is integrated in the high fidelity flight simulator, which consists of both aircraft and Real world systems either as actual or simulated for close loop pilot evaluation. The behaviour of the sensor model is cross validated and fine-tuned with the actual sensor output and confirmed that the developed laser designated pod sensor simulation model meets all the requirement to test the air to ground weapons in the flight simulator

Elucidation of genetic diversity through Multivariate analysis in brinjal (Solanum melongena L.) landraces for varietal improvement

Genetic diversity plays a crucial role in harnessing the potential of crop genotypes for genetic improvement. It helps to identify, preserve, and utilize diverse landraces effectively. This research aimed to assess the level of genetic diversity and traits enhancing genetic variation among 46 brinjal genotypes (Solanum melongena L.) in preparation for a special breeding programme to utilize the potential landraces. Genetic divergence among 46 genotypes of brinjal for eleven characters was assessed using the D2 method. The studied genotypes were categorized into eight clusters. Cluster I with 15 genotypes was the largest followed by Cluster IV (14 genotypes), Cluster V (7 genotypes), Cluster VII (4 genotypes), Cluster III (3 genotypes), Clusters II, VI, and VIII with one genotype each. The intra-cluster D2 values ranged from 0.00 (Cluster II, VI and VII) to 103.53 (Cluster III). The inter-cluster distances varied from 117.00 to 791.17. Cluster II and Cluster VII had the greatest inter-cluster distance (791.17), followed by Cluster II and VIII (673.41), and Cluster VII and Cluster V had the smallest inter-cluster distance (117.00). Crossing genotypes in clusters with wide inter-cluster distances improves recombinant isolation in segregating generations. The three traits- number of flowers per inflorescence (23.8%), average fruit weight (17.68%) and days to first flowering (16.81%) altogether contribute to 57.8% of the total divergence. The combination of these traits could be useful to produce high-yielding climate resilient varieties from valuable landraces

Comparative study of Merits and Demerits of Laparoscopic Cholecystectomy Versus Open Cholecystectomy

CONCLUSION: In my study I conc1ude that Laparascopic cholecystectomy is advantage over open cho1ecystectomy for fo11owing reasons associated with Laparoscopic group. a) Ear1ier return of Bowel activity, b) Lesser postoperative pain and Analgesic requirement, c) Shorter hospital stay, d) Earlier return to work, e) Cosmetic superiority, J) Cost effectiveness, g) Lesser complication rate. With re1ative increase in Operative time was observed in 1aµaroscoµic group due to 1earning curve of junior residence. Conversion rate in our study is simi1ar to other studies

A Study on Foreign Direct Investment on Special Reference towards FDI Developed Countries

Foreign direct investment (FDI) has been one of the defining characteristics of the world economy during the last two decades. Some developing economies have emerged as major recipients of FDI flows in recent years, while many others have attempted to attract such flows, often by offering fiscal and financial value to foreign investors. This work reviews and discusses recent empirical studies on key development issues related to FDI. The literature review focuses on five main areas of interest to host economies: the FDI-growth nexus; FDI-trade linkages; FDI and technology transfer; FDI, privatization and corporate governance; and host- government policies for attracting FDI. Three of the conclusions reached in this study deserve special attention. First, a vast majority of existing empirical studies indicate that FDI does make an appositive contribution to both income growth and factor productivity in host economies. FDI tends to “crowd in” domestic investment, as the creation of complementary activities outweighs the displacement of domestic competitors. Similarly, in the North-South context, the relationship between FDI and trade is more one of complementarily than of substitution, owing to backward and forward linkages. Second, host countries will not be able to capture the full benefits associated with FDI until they reach a certain threshold level regarding educational attainment, provision of infrastructure services, local technological capabilities and the development of local financial markets. Third, their role of FDI in development goes beyond the traditional areas of growth, trade and technology transfer to cover emerging areas of policy concern, such as mergers and acquisitions, privatization, corporate governance and “policy competition.” The study concludes by stressing that host-government policies should attach greater importance to the stability and redictability of the local business environment in which MNE affiliates operate

MORPHOLOGICAL VERSUS MOLECULAR CHARACTERIZATION OF THREE SIMILAR PIERID SPECIES OF BUTTERFLIES

The morphological diversity and genetic similarity of three Pierid species (both male and female) of butterflies- Pieris canidia, Pieris napi and Pieris brassicae has been studied. RAPD-PCR analysis using seven decamer primers produced discrete bands of various size revealing genetic variations as well as similarities among the three species of butterflies. Some specie