Reset control for DC-DC converters: an experimental application

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Power converters in grid connected systems are required to have fast response to ensure the stability of the system. The standard PI controllers used in most power converters are capable of fast response but with significant overshoot. In this paper a hybrid control technique for power converter using a reset PI + CI controller is proposed. The PI + CI controller can overcome the limitation of its linear counterpart (PI) and ensure a fast flat response for power converter. The design, stability and cost of feedback analysis for a DC-DC boost converter employing a PI + CI controller is explored in this work. The simulation and experimental results which confirm the fast, flat response will be presented and discussed.Peer ReviewedPostprint (published version

An adaptive disturbance rejection control scheme for voltage regulation in DC micro-grids

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Uncertain generation by renewable sources and load variations have resulted in adding energy storage systems in the grid to maintain grid parameters (voltage, frequency) within prescribed limits. The disturbances being non-deterministic in nature, the voltage regulation control by the storage systems relies mostly on dual loop architecture with an outer voltage and inner current loop. Improvement in controller dynamics can be achieved through feed forward of disturbance profile but at expense of additional sensors and communication in the grid. This work explores the application of an adaptive disturbance rejection control scheme for disturbance estimation (without using additional sensors) employing an extended state and proportional integral observer (PI+ESO). The proposed observer aim to achieve robust disturbance estimation under grid parameter uncertainty. The effectiveness of the proposed scheme over the conventional one will be put forward through H8 and H2 norm analysis of the system. The design and simulation results of the proposed scheme will be presented in this work.Peer ReviewedPostprint (author's final draft

Importance of biosensors

• The term biosensor appeared in the 1960s to define the use of bio electrodes involving enzyme electrodes that presented and bio catalytic activity. In 1962, Leyland C. Clark brought the very rudimentary model of biosensors forward with the early invention of an oxygen electrode in which the electrochemical detection of oxygen or hydrogen peroxide could be used for a broad choice of bio analytical purposes. Since then, biosensors have expanded giving rise to a vast frontier of interdisciplinary research that combines biology, analytical chemistry, physics and bio-electronics. From the first bulky biosensors built as academic curiosity, the field has shown a great deal of attractiveness thus becoming a research area that has successfully commercialized devices for multiple applications in a market that is worth many billion dollars. Different uses in medico-clinical, environmental, food-agricultural, security and forensic science, and other fields are making these devices increasingly popular. The question of defining what we can consider as a biosensor is difficult, but the most accepted concept nowadays is to be a device comprising of a biological recognition element attached or integrated into a transducer. • The research developed in this area is certainly increasing. A Scopus study in the publication period 1972-2014 using the word ‘biosensor’ revealed an exponential trend in the number of publications in this field (Figure 1). In the same temporal period the study revealed that the USA remains as the most important country in terms of research in biosensors, followed by China and Germany (Figure 2). However if this period is restricted to the last 5 years (2009-2014) the study reveals that China’s influence in this field is gaining momentum and countries like South Korea and India are increasingly researching in these areas with a higher number of publications being released in this field (Figure 3). • It is likely that the publication trend will continue and with biosensors becoming smaller through miniaturization and into the nanoscale range, the number of applications and research devoted to this field will only increase

“Building from bottom” a success story

Rajkot Municipal Corporation (RMC) is a local government committed to provide basic infrastructure facilities including entertainment facilities to the people of the city. RMC is very well known for managing the city by using private sector participation as well as introduction of innovative mechanisms in management to serve people efficiently. City has prepared different plans for improving services and to nullify the gap between services and demands. The sole responsibility of Solid Waste Management (SWM) in the city lies with the Soild Wate Management department of Rajkot Muncipal Corporation (RMC)

Traditional Plant Fencing and its Conservatory Nature in Kasaragod District, Kerala, India

Villages of Kasaragod District are centres of agricultural practices. The fields often face the threat of wild animals and grazing. To overcome these problems temporary or permanent fences are made using different plants. These fences not only protect the fields but also play an important role in the conservation of some plants. The paper lists 67 plant species used by the villagers of Kasaragod District, Kerala for fencing