M.Tech, B-Tech

Rajasree S. R. currently serves as Assistant Professor (Sr. Gr.) at the Department of Electrical and Electronics Engineering at Amrita School of Engineering, Amritapuri. She has completed M. Tech. in Control Systems from College of Engineering, Trivandrum, in the year 2010. She is currently pursuing Ph.D.


Publication Type: Conference Paper

Year of Publication Title


Rajasree S. R., V. Pandi, R., and Ilango, K., “Power Quality Analysis for Brushless DC Motor Drive Fed by a Photovoltaic System Using SRF Theory”, in Innovations in Electrical and Electronics Engineering, Singapore, 2020.[Abstract]

Harmonic contents present in power network have adversely affected the power quality and this reduces the stability of the system. In this paper, active filter-based compensation has been developed using the PV source. A nonlinear BLDC load is considered which injects more harmonic current in the system whereby increasing the total harmonic distortions (THD). This THD value needs to be maintained below the permissible limit by properly controlling the shunt active power filter (SAPF) to get effective compensation. In this work, synchronous reference frame (SRF) theory is used to produce the compensating current required for canceling the harmonic content produced by the BLDC load and for compensating the reactive power. The energy to active filter is obtained from PV array and the intermediate DC-to-DC converter stage is used to smoothen the operation of BLDC motor drive. The complete system is modeled and simulated in MATLAB Simulink. From the simulation analysis, it shows that the reduction of THD (%) is within the limits and VAR compensation is achieved thereby improving the power factor.

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A. P., Praveen, A. D., Narayan, G., J., S., Kumar, H., Rajasree S. R., and M.S., A., “Microcontroller based Intelligent Braking System in Electric Scooters”, in 2020 5th International Conference on Communication and Electronics Systems (ICCES), Coimbatore, India, 2020.[Abstract]

In recent years, road accidents usually occur as a result of the laxity of drivers, and the number of such accidents is increasing exponentially. Lack of care, sleep, and attention is considered as the primary factors. In this perspective, the proposed work discusses a new strategy by which an electric scooter can stop, to avoid a fatal accident. Here, a microcontroller-based braking methodology is employed. With the use of ultrasonic sensors, it appropriately detects the fast approaching obstacles in front of the scooter. Continually, the received signals are used by the microcontroller to proceed the further braking action. Also, the system has been made by considering the vehicles driven by a disabled person so that the driver can avoid the panic situation while the emergency braking is on demand.

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B. Shilpa, Indu V., and Rajasree S. R., “Design of an underactuated self balancing robot using linear quadratic regulator and integral sliding mode controller”, in 2017 International Conference on Circuit ,Power and Computing Technologies (ICCPCT), Kollam, India, 2017.[Abstract]

This paper describes the design procedure of an underactuated self balancing robot using LQR and ISMC. The two wheeled self balancing robot works on the principle of inverted pendulum concept so it is otherwise referred to as two wheeled inverted pendulum mobile robot. The two WMR is widely used in many applications such as a personal transport system (Segway), robotic wheelchair, baggage transportation and navigation etc. LQR and ISMC are introduced into the system in order to achieve the set point control task. That is the 2 WMR should reach the desired set point and then stops while keeping the balance. Both the controller will track the system but the performance of the controller slows some slight differences. By using the MATLAB simulation, two methods are compared and discussed. Also the load transportation task is also assigned to this 2 WMR and controlled using LQR controller.

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J. Freeman, U., K. E., and Rajasree S. R., “Study of the errors influencing heliostats for calibration and control system design”, in International Conference on Recent Advances and Innovations in Engineering (ICRAIE-2014), Jaipur, India, 2014.[Abstract]

“Power tower” or central receivers are a type of solar thermal energy system in which many heliostats, or movable planar mirrors, are used to focus sunlight onto a central receiver located on top of a tower. To design a control and calibration system for power tower systems, a thorough understanding of the numerous errors which can be present is essential. In this work, the various and different types of errors that present themselves in heliostat based solar energy systems are identified, categorized and assessed based on their potential impact and level of difficulty of resolution. The results of this work can be used to aid in designing a control system for heliostats in which the greatest amount of error can be corrected with the least difficulty.

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