Qualification: 
Ph.D
kk_sasi@cb.amrita.edu

Dr Sasi K Kottayil had his basic and post graduate degrees in Electrical Engineering and doctoral degree on Utility Scale Wind Electricity Generation. He has been in teaching profession since 1984. He served earlier as faculty member at North Eastern regional Institute of Science and Technology, Itanagar (1986 to 2004); and also in Department of Energy at Tezpur University, Assam. He is currently Professor in Electrical & Electronics Engineering, Amrita School of Engineering, Coimbatore at Amrita Vishwa Vidyapeetham University, Coimbatore. Renewable Energy and Smart Micro Grid are the areas of his interest.

Dr Sasi K Kottayil is a Fellow and Past President of the Society of Energy Engineers and Managers (SEEM), and Editorial Advisor of the SEEM magazine - Energy Manager.
Dr Sasi also serves as a consultant for Renewable Energy development for the past 10 years. He has been the Project Director of Ahalia Alternate Energy Pvt Ltd, during 2015-16 when they developed 8.4 MW wind farm. He has been the Consultant to the Swedish Consortium that develops E4T Microgrid Concept, a RE project for Andaman & Nicobar Islands during 2015-16. He served as a member of the Technical Committee of ANERT, Govt of Kerala, for development of windfarms in Kerala, from 2004 to 2015.

He served during 2008-2012 as a member in R&D subgroups of Centre for Wind Energy Technology (C-WET), Govt of India. He was awarded Kerala State Energy Conservation Commendation Certificate in 2009 in the category of Research and Innovation. Dr Sasi was awarded a Fellowship by European Union to attend Salzburg Seminar on Global Energy Fulcrum: Asian Development and International Response held at Salzburg, Austria in Nov-Dec 2008. He also visited Uppsala University, Sweden as a visiting faculty in June 2008, and Royal Institute of Technology, Stockholm in 2012. He was selected for the Prometeo Project of Equador government in 2013. Elsevier International Journal of Energy recognized Dr Sasi as their Outstanding Reviewer in 2014. He is a member in the Advisory Committee of Centre of Excellence in Alternate Energy Research, Government College of Technology, Coimbatore during 2014-17. Dr Sasi is one amongst the authors who won The IET Premium Awards 2016 for their paper in IET international journal of Power Electronics. He served as Guest Editor of Procedia Technology for its Special Issue on Smart grid Technologies, (Vol 21, 2015).

Dr Sasi was the Principal Investigator of the DST-VINNOVA funded Indo-Swedish research project, Energy Management on Smart Grid using Embedded Systems (2011-14). He developed and conducted two PG Diploma programmes on Wind Energy under a MoU with C-WET and Indian Wind Turbine Manufacturers Association (2011-2013). He has developed a renewable Energy laboratory at Amrita University that has advanced research facilities which include a Smart Micro Grid Simulator.

Dr Sasi has published more than 100 research papers, delivered more than 200 invited lectures, chaired several sessions in national and international conferences, carried out nine sponsored research projects from DST, MHRD, C-WET, NEC , GIAN etc., and reviewed several papers for International Journals. He is guiding several PhD students in the area of Energy.

Publications

Publication Type: Journal Article

Year of Publication Publication Type Title

2016

Journal Article

P. Vadana, ,, and Dr. Sasi K. K., “Dynamic energy management on a hydro-powered smart microgrid”, Advances in Intelligent Systems and Computing, vol. 397, pp. 627-635, 2016.[Abstract]


Penetration of renewable energy-based microgrids onto the legacy grid is in demand to solve the global energy problems and the environmental issues. This paper attempts to employ dynamic energy management on a Grid-Connected Smart Microgrid (GCSMG) energized by a Micro Hydro Power Plant (MHPP) sans governor control. Frequency control of such SMGs poses a challenge as the latter is distributed. The concept of Dynamic Energy Management (DEM) plays a significant role in accomplishing the frequency control without perturbing the controlling facility in the conventional grid. DEM is a concept of controlling the charge-discharge transactions on the energy storage modules to oppose the frequency excursions on the grid. Support Vector Machine (SVM) algorithm is employed to automate DEM operation. The Dynamic Energy Management System (DEMS) is implemented on a Field Programmable Gate Array (FPGA) as the response time is critical for this application. The DEM scheme is validated on the SMG simulator in the Renewable Energy Laboratory of Amrita Vishwa Vidyapeetham University, Coimbatore. © Springer India 2016.

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2015

Journal Article

N. T.P., P., S., and Dr. Sasi K. K., “Sensor Based Communication Network for WACS with DNP3”, Procedia Technology, vol. 21, pp. 76 - 81, 2015.[Abstract]


Smart grid is the emerging electricity network envisaged to connect the supplier and the consumer by two-way digital communication. One of the main attractions of the smart grid is the Wide Area Control System (WACS) with distributed controllers which actuate the instructions issued by the central controller. This paper focuses on the hardware implementation of a communication network for WACS in which ZigBee is used as the communication technology from the control station to the control unit. The control message sent should follow Distributed Network Protocol version 3 (DNP3), which is an IEEE standard for communication between central station and Intelligent Electronic Devices (IEDs). The simulation is done in network simulator (ns2), in which the number of packets follows the DNP3 format. Using mbed board a network topology is created for the WACS communication network and the control messages are communicated from the control station to the control units to validate a satisfactory performance.

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2015

Journal Article

A. G.S., Sivraj, P., and Dr. Sasi K. K., “Resource Management on Smart Micro Grid by Embedded Networking”, Procedia Technology, vol. 21, pp. 468–473, 2015.[Abstract]


Smart Grid, the next generation electric grid offers continuous monitoring and control which needs management of resources like measured data, control information, relays, switches etc. These resources will increase as the grid emerges and management of these scattered, bulk and highly complicated data will become difficult with conventional data storing and resource management mechanisms, which makes the cloud model of resource management relevant and significant. This paper deals with the formation of an embedded networking with six systems. Graphical User Interfaces (GUI) are created for different stake holders like consumers, energy traders, operators etc. through which they can access and control the grid assets. The proposed system will improve the performance of the grid by enabling various functionalities such as: analyzing energy usage, managing peak usage, demand management, trading of electricity between smart grid stakeholders such as consumers, operators, generators etc., which ensure efficient operation and management of the smart micro grid.

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2015

Journal Article

T. P. Neeraja, Sivraj, P., and Dr. Sasi K. K., “Wide Area Control Systems (WACS) Implementation Based on Sensor Network Concepts”, Procedia Technology, vol. 21, pp. 303–309, 2015.[Abstract]


Wide Area Control Systems (WACS) are introduced to respond to the real time control requirements of a smart grid. The control messages in smart grid can be of different levels of criticality. Therefore priority based routing, depending on criticality of messages, is very essential in control message communication. The topology of the system considered, involves control units connected to five buses in a smart micro grid. The performance metrics are identified and threshold values are fixed. Different communication technologies are simulated and the performance is compared. Multi hopping communication is established between the nodes and heterogeneous communication architecture is implemented. The need for dynamic routing protocol in the grid, as the traffic on the network changes over time, is also met. A communication scenario which dynamically routes the control message from central station to control units depending on priority, through the shortest path available, is identified here.

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2011

Journal Article

N. G. Greeshma and Dr. Sasi K. K., “Active power control in wind driven variable speed squirrel-cage induction generator”, Bonfring International Journal of Power Systems and Integrated Circuits, vol. 1, p. 56, 2011.[Abstract]


This paper describes active power control in a grid connected variable speed wind electric generation system (WEG) using squirrel cage induction machine. The chosen variable speed WEG system consists of a wind turbine, squirrel-cage induction generator, an AC-DC-AC interface and the power grid. In this work the generator side converter is controlled using vector control of induction machine and the grid side converter is controlled using DC link voltage control. Active power delivered by the WEG to the grid when driven by a wind speed can be controlled, albeit within a limited range, by varying the DC link voltage at the input of the grid side converter. The WEG scheme is simulated using system models in MATLAB-Simulink and the performance is studied. More »»

2009

Journal Article

C. K. Ratheesh, Devarajan, A. T., TNP, N., Dr. Sasi K. K., and Isha, T. B., “Operation of Induction Motor at Optimum Efficiency ”, Operation of Induction Motor at Optimum Efficiency, 2009.[Abstract]


Abstract—In this paper an 8 switch PWM three phase AC chopper is used to control the stator voltage of a three phase induction motor. Three different control strategies viz., keeping the power factor constant, keeping the stator current minimum and keeping the input power minimum for a given load, are used to operate the induction motor at maximum efficiency. The results obtained from a closed loop simulation using MATLAB and experimental validation in open loop, are presented here. More »»

2005

Journal Article

H. Basumatary, Sreevalsan, E., and Dr. Sasi K. K., “Weibull Parameter Estimation — A Comparison of Different Methods”, Wind Engineering, vol. 29, pp. 309-315, 2005.[Abstract]


The Weibull probability function is a widely accepted tool to model wind regimes. This paper presents a comparative study of different methods used to estimate Weibull parameters of a wind regime. Five different methods are described and used for the estimation. Time series data of wind speed over a whole year for two sites have been used for the study. The results obtained as a plot of error versus wind speed are similar in all the five methods, yet the method of standard deviation gives the best results. More »»

2004

Journal Article

A. Chakraborty, Saha, P., Acharjee, A., and Dr. Sasi K. K., “Energy conservation in ceiling fans”, Proceedings of the 13th National Power Systems Conference, pp. 835-838, 2004.[Abstract]


The paper deals with energy conversion efficiency of commercial models of ceiling fan. The investigation and the following analysis show that in the tested samples, notwithstanding that the minimum performance standards suggested by BIS are satisfied, the matching between the motor and the rotor blades is not optimal and so there is scope for improving fan system efficacy through design modifications. The paper presents the test results and suggests energy efficient system design. More »»

2004

Journal Article

Dr. Sasi K. K., “Wind Power The Technology Options”, ELECTRICAL INDIA, vol. 44, no. 11, pp. 36-39, 2004.

2004

Journal Article

Dr. Sasi K. K. and Isha, T. B., “Energy Conservation in Industrial Motors”, ELECTRICAL INDIA, vol. 44, no. 4, 2004.

2003

Journal Article

Dr. Sasi K. K., “The Technical Perspective of Wind Power Planning”, ELECTRICAL INDIA, vol. 43, no. 11, 2003.

2002

Journal Article

Dr. Sasi K. K. and Basu, S., “Windfarming in India—the desired policy recast”, Energy, vol. 27, pp. 241 - 253, 2002.[Abstract]


The Indian wind energy programme suffered a recent setback after being placed third in terms of total installed capacity of wind electricity in the world. This paper submits, based on analysis of field performance data, that the falling profitability of private windfarm operation in the country today can hardly attract large scale investment in the private sector. It further suggests that a right choice of wind electric generators with an optimum rated wind speed will improve the windfarm performance. The steps to be adopted by the government agencies in order to ensure the desired growth of the wind industry in the country have also been suggested. These in turn invite certain changes in the present windfarm development policy of the country. More »»

2000

Journal Article

Dr. Sasi K. K. and Basu, S., “Review of Wind Energy Commercialisation in India”, Wind Engineering, vol. 24, no. 2, 2000.[Abstract]


Sustainability of a power scheme is decided by viability of the technology, adaptability for integration into existing infrastructure, economic competence and environmental acceptance. The 15 year long Indian experience in wind electric power generation certainly suggests improvements in design and operation of the system, although the technology as such is passing through various phases of innovation in the international scene. More »»

2000

Journal Article

Dr. Sasi K. K. and Basu, S., “Energy storage for intermittent bulk electricity generation from renewable resources”, WATER AND ENERGY INTERNATIONAL, vol. 57, pp. 19–25, 2000.

1997

Journal Article

Dr. Sasi K. K. and Basu, S., “On the prediction of capacity factor and selection of size of wind electric generators- a study based on Indian sites”, Wind Eng, vol. 21, pp. 73–88, 1997.[Abstract]


The capacity factor (CF) of a wind electric generator (WEG) at a site has been computed based on the Weibull parameters of the wind regime as well as the machine characteristics. Every wind regime suggests an optimal wind speed rating of the WEG to produce the maximum energy on an annual basis. However, the selection of a WEG size suitable for a site should be based on the economically optimal wind speed rating which will produce energy at the minimum cost. The paper presents these estimates for selected Indian sites and also discusses the factors that influence these ratings. More »»

1997

Journal Article

Dr. Sasi K. K. and Basu, S., “Growth prospects of wind energy in India”, Journal of the Institution of Engineers (India), Electrical Engineering Division, vol. 78, pp. 117–120, 1997.

1995

Journal Article

Dr. Sasi K. K., “Electrical Equipment for Potentially Explosive Environment”, ELECTRICAL INDIA, vol. 35, pp. 3-5, 1995.

1990

Journal Article

Dr. Sasi K. K., NEOGI, S. U. B. H. A. S. I. S., SHARMA, S. O. U. M. Y. A. S. E. N., and Basu, S., “TESTING OF WIND GENERATORS IN INDIAN CONDITIONS AN OVERVIEW AND APPRAISAL”, Integrated renewable energy for rural development: proceedings of the National Solar Energy Convention, Jadavpur University, Calcutta, India, December 19-21, 1990, p. 393, 1990.

Publication Type: Conference Paper

Year of Publication Publication Type Title

2014

Conference Paper

V. D. Prasanna and Dr. Sasi K. K., “Energy-aware Intelligent Controller for Dynamic Energy Management on Smart Microgrid”, in 2014 Power and Energy Systems Conference: Towards Sustainable Energy, PESTSE 2014, Bangalore, 2014.[Abstract]


A Dynamic Energy Management (DEM) controller which is capable of taking decisions based on the status of the grid-connected smart microgrid has been developed using Support Vector Machine (SVM) and Artificial Neural Networks (ANN). The proposed control strategy involves the decisions for the dynamic charge-discharge transactions in the energy storage systems like battery and pumped hydro (PH) units connected to the smart microgrid in order to maintain a real time balance of generation and load. A comparison has been made based on the realizations of both SVM model and ANN model on SPARTAN 3AN Field Programmable Gate Array (FPGA) and the results show that SVM implementation is better than ANN implementation. The projected DEM system when tested with the existing laboratory model of a smart microgrid results in sustainable supply of power as the SVM based DEM controller monitors power flow in the lines and provides an optimal solution. © 2014 IEEE.

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2014

Conference Paper

A. V. Panikulam, Megha, I. P., Teja, A. V. N. Sai, Pandey, S., Prajof, P., and Dr. Sasi K. K., “A low cost grid interface for DFIG using SPWM technique”, in 2014 Power and Energy Systems Conference: Towards Sustainable Energy, PESTSE 2014, Bangalore, 2014.[Abstract]


Grid integration of a laboratory scale Doubly Fed Induction Generator (DFIG) has been carried out and reported here. The stator of the DFIG is directly connected to the grid and the rotor is interfaced to the grid through a pair of back to back converters (rectifier and inverter). A low cost control scheme using sinusoidal pulse width modulation (SPWM) technique is used in the inverter to match the rotor voltage, phase and frequency with those of the grid and also to facilitate power transfer by creating a phase shift. Complexity in the interface controller is avoided as it allows only super synchronous generation. The scheme has been successfully validated in laboratory and the results are presented here. © 2014 IEEE.

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2014

Conference Paper

N. S., Sivraj, P., Dr. Sasi K. K., and Lagerstöm, R., “Development of a Real Time Data Collection Unit for distribution network in a smart grid environment”, in 2014 POWER AND ENERGY SYSTEMS: TOWARDS SUSTAINABLE ENERGY, 2014, pp. 1-5.[Abstract]


This paper proposes a Real Time Data Collection Unit (RTDCU) to be used in the distribution side of a smart grid for real time data collection. The RTDCU unit uses Discrete Fourier Transform (DFT) based approach to compute the voltage and current phasors and frequency of the power system signals. The design, development and testing of such a system is done for a 5-bus micro grid simulator which represents a scaled down model of approximately 25km2 grid with a peak demand of 15MW. The RTDCU unit is first simulated and tested in MATLAB environment using synthetic signals and the correctness is ensured. The unit is then implemented in hardware in a dsPIC30f4011 microcontroller and tested for different loads. The future scope of the unit and the ways to improve the performance and synchronized data collection are also discussed. More »»

2014

Conference Paper

D. Ea Soman, Krishna, Ra, Leijon, Ma, Vikram, Kb, Dr. Sasi K. K., Vitoi, L. Ac, Oliveira, J. Gc, and Kumar, S. Sd, “Discontinuous conduction mode of a three-level boost DC-DC converter and its merits and limits for voltage cross regulation applications”, in Proceedings, IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society, 2014, pp. 4268-4272.[Abstract]


<p>Distributed generation and smart grid integration of renewable energy sources introduce a lot of challenges for the enabling power electronic converter technology. Some of these challenges include wide controllability range, high power handling and good reliability. Three-level boost converter is one of the attractive solution for applications requiring voltage cross regulation such as three-level neutral point clamped inverter based grid integration of renewable sources. The present work shows the advantages and disadvantages of using discontinuous conduction mode of a Three-level boost converter for voltage cross regulation. The converter working principle, modes of operation and operating cases are listed briefly. The simulation results compare the DCM and CCM cross regulation effects. Based on these results, the controllability range of the converter is analyzed to understand the suitability of the converter for various applications. © 2014 IEEE.</p>

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2012

Conference Paper

S. Nithin, Dr. Sasi K. K., and Nambiar, T. N. P., “Development of a smart grid simulator”, in Proceedings of national conference on power distribution, CPRI, India, 2012.

2010

Conference Paper

R. Krishna, Deepak, E. S., Dr. Sasi K. K., and Leijon, M., “Space vector modulation method to balance the neutral voltage for a three level inverter”, in 2010 Joint International Conference on Power Electronics, Drives and Energy Systems 2010 Power India, 2010.[Abstract]


This paper investigates the capacitor voltage balance scheme for a neutral point clamped inverter. A symmetrical space vector modulation is used to analyze the imbalance in neutral point voltage. This method overcomes the drawbacks of Nearest Three Vector modulation method. The redundancies of different switch configurations for the generation of the same output voltage are used to limit the voltage drift when modulation index is less than half. The deviation in the neutral voltage is further reduced by adjusting the duty cycle distribution variable. The voltage balance scheme is analyzed for linear and non linear loads. The performance of control strategy is also examined for a grid connected inverter. More »»

2010

Conference Paper

R. Krishna, Dr. Sasi K. K., and Leijon, M., “Predictive current controller for a grid connected three level inverter with reactive power control”, in 2010 IEEE 12th Workshop on Control and Modeling for Power Electronics (COMPEL), 2010.[Abstract]


This paper presents a predictive method of current control for grid connected three level neutral point clamped inverter in synchronous rotating frame. The predictive current controller calculates the inverter voltage required to force the load current to follow the reference. To validate the performance the computational time has been compared with DSP processor TMS320C240 and the maximum permissible sampling frequency is calculated. Transient performance of the controller is analyzed. The proposed controller also validates the neutral voltage balancing and reactive power control. Three phase balanced current injection to the grid with reactive power control has been attained. The decoupled control over active and reactive power has been achieved through the variation of synchronously rotating two axis currents. More »»

2010

Conference Paper

R. Krishna, Dr. Sasi K. K., and Leijon, M., “Direct predictive current control of grid connected neutral point clamped inverter for wave power extraction”, in SPEEDAM 2010, 2010, pp. 175-179.[Abstract]


In consequence of the generic irregularity of wave energy, it is difficult to envisage the performance of a grid connected wave energy converter without simulations. This paper details a study on directly driven, linear, permanent magnet generator based, wave energy extraction scheme provided with grid-connected three phase neutral point-clamped three level inverter. The linear permanent magnet generator is driven by a magnetic translator undergoing reciprocating motion with the floating buoy according to wave movement. It converts the mechanical power to three phase AC power. The converter-inverter system provides a fast, dynamic power balancing from generator to grid. The predictive current controller is used to control the three phase neutral point clamped inverter which calculates the inverter voltage required to force the load current to follow the reference. Simulation model of the system is implemented in Matlab/Simulink. The DC-link voltage is regulated by the converter. Neutral point voltage balancing is achieved through proper selection of inverter switching states. Three phase balanced current injection to the grid at unity power factor has been attained. The results obtained validate effectiveness of the predictive method of current control. More »»

2009

Conference Paper

R. K. and Dr. Sasi K. K., “Active Power Control in Variable Speed Wind Electric Generators”, in 2009 International Conference on Advances in Computing, Control, and Telecommunication Technologies, 2009.[Abstract]


This paper presents the performance analysis of a variable speed wind energy conversion system that employs permanent magnet generator (PMG) coupled to horizontal axis wind turbine. The study involves a computer simulation of the wind turbine driven PMG connected to the grid through an inverter. The switching signal for the PWM inverter has been generated by a method of DC link voltage control adopted for control of active power transferred through the system. The dynamic model of the wind power conversion system is developed using MATLAB/Simulink software. More »»

2009

Conference Paper

V. V. and Dr. Sasi K. K., “Dynamic Analysis of a Grid-Connected Wind Electric Generator with Embedded Static VAR Compensator”, in 2009 International Conference on Advances in Computing, Control, and Telecommunication Technologies, 2009.[Abstract]


This paper describes modeling and simulation of Wind Electric Generator (WEG) comprising a pitch controlled Horizontal Axis Wind Turbine (HAWT) coupled to squirrel cage induction generator through a gear. The generic issue of VAR drain from the grid by the generator is tackled by the use of Static VAR Compensators (SVC). The paper presents the results of the dynamic performance of the complete system under varying wind conditions. The model accommodates the effects of wind turbulence and the simulation is carried out using MATLAB - SIMULINK 7.1. More »»

2006

Conference Paper

P. V. Kumar, Meera, K. S., and Dr. Sasi K. K., “Transient Fault Response of Grid Connected Wind Electric Generators”, in 2006 International Conference on Power Electronic, Drives and Energy Systems, 2006.[Abstract]


The paper deals with simulation studies on grid connected wind electric generators (WEG) employing squirrel cage induction generator (SCIG) and doubly fed induction generator (DFIG). Their dynamic responses to wind speed variations and transient faults on transmission line are studied. More »»

Publication Type: Conference Proceedings

Year of Publication Publication Type Title

2014

Conference Proceedings

M. Välja, Honeth, N., Buschle, M., Lagerström, R., Dr. Sasi K. K., and Nithin, S., “An archimate based analysis of microgrid control system architectures”, Embedded Systems (ICES), 2014 International Conference on. pp. 297-301, 2014.[Abstract]


The architectures containing embedded systems such as microgrid controllers are becoming more complex. While there are several known methodologies for embedded system modeling and design, they mostly cover development related performance issues. There exists a gap in the management of architectures implementing embedded systems for power systems applications. This paper proposes to use enterprise architecture analysis, based on earlier work, to fill that gap. Availability, interoperability and cost analysis are in focus. Enterprise architecture models are important in order to abstract the technical detail for planning and design in order to provide a basis for discussion of technical scalability and cost management amongst stakeholders and technical experts. A microgrid control architecture based example is given to illustrate the analysis possibilities.

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2007

Conference Proceedings

V. P. Kumar, Meera, K. S., and Dr. Sasi K. K., “Transient Fault Response of Grid Connected Wind Electric Generators”, Power Electronics, Drives and Energy Systems, 2006. PEDES '06. International Conference on. IEEE, 2007.[Abstract]


The paper deals with simulation studies on grid connected wind electric generators (WEG) employing squirrel cage induction generator (SCIG) and doubly fed induction generator (DFIG). Their dynamic responses to wind speed variations and transient faults on transmission line are studied. More »»
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