Qualification: 
Ph.D, M.E
k_deepa@blr.amrita.edu
Phone: 
9980005071

Dr. K. Deepa currently serves as Assistant Professor at the department of Electrical & Electronics, Amrita School of Engineering, Bengaluru campus. She has more than 20 year of experience in teaching. She has 25 international journal papers, twenty nine international conference papers and six national conference papers to her credit. She has authored two books “Control Systems” and “Electrical Machines”. Her Ph.D. thesis title was “Design, Analysis and Control of DC to DC Quasi Resonant Converters”. She is a senior member of Institute of Electrical and Electronics Engineers (IEEE) & IEEE Power and Energy Society (PES) and life member of Institution of Electronics and Telecommunication Engineers (IETE) & Indian Society For Technical Education (ISTE). She is the advisor for the IEEE-PES& IAS student branch joint chapter and advisor for IEEE-WIE in Amrita School of Engineering, Bengaluru.

Currently she is guiding her Ph. D., M. Tech. and B. Tech. students in the area of Electric Vehicles, Battery management systems, Smart Grid, Power Electronics Applications to Power Systems & Renewable energy Technologies, Soft Computing, Drives, Intelligent Control Techniques & Control System, Power Quality, FACTS Devices, Multi-level Inverter, Resonant Converters

Course College/ University Duration
Ph.D(Power Electronics) JNTU, Anantapur June 2008 – January 2016
M.E.(Power Electronics and Drives) College of Engineering, Guindy/ Anna University, T.N June 2002 – April 2005
B.E. (EEE Alagappa Chettiar College of Engineering and  Technology/ Madurai Kamaraj University, T.N 1994 – 1998

Publications

Publication Type: Journal Article

Year of Publication Title

2018

P. T, Dr. K. Deepa, and R, M., “Hardware Implementation Of Three Phase Five-Level Inverter With Reduced Number Of Switches For PV Based Supply”, Journal of Green engineering, vol. 7, no. 4, pp. 527- 546, 2018.[Abstract]


This paper proposes a three phase five-level inverter which uses a single DC (PV) source, unlike a conventional cascaded H-bridge (CHB) which requires multiple DC (PV) sources, and also a novel Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) for reduced voltage Total Harmonic Distortion (THD) compared to a conventional SHE-PWM. The proposed inverter uses reduced number of switches when compared to conventional inverter. The proposed three phase inverter is simulated in MATLAB with both conventional and new SHE-PWM techniques. The simulated waveforms of the line, phase voltages and load current are studied in detail. A comparison of THD values is for both conventional and proposed SHE-PWM is presented. This is followed by the hardware implementation of the proposed inverter with the new SHE-PWM, and the results for line, phase voltages and the load currents are again reviewed. The hardware results are found to match the simulation results. The results confirm that the proposed SHE-PWM has the ability to deliver a reduced THD when compared to a conventional SHE-PWM.

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2018

T. Porselvi, Dr. K. Deepa, and Muthu, R., “FPGA Based Selective Harmonic Elimination Technique for Multilevel Inverter”, International Journal of Power Electronics and Drive Systems, vol. 9, pp. 166-173, 2018.[Abstract]


Harmonic elimination at the fundamental frequency is very much appropriate for high and medium range of power generation and applications. This paper considers a new technique for selective harmonic elimination (SHE), in which the total harmonic distortion (THD) is minimized when compared with that of the conventional one. With this technique, the harmonics at lower order are eliminated, which are more predominant than the higher ones. Cascaded H-Bridge inverter fed by a single DC is considered which is simulated with the switching angles generated by both the conventional method of SHE and the new method of SHE. The simulated results of the load voltage and the waveforms of the harmonic analysis are shown. The THD values are compared for the two techniques. The experimental results are also shown for the new technique. The switching angles are generated with the help of field programmable gated array (FPGA) in the hardware. The value of experimental THD of voltage is compared with that of simulated THD and the comparison prove that the results are satisfactory.

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2017

Dr. K. Deepa and V, P. Kumar., “Voltage Imbalances Mitigation Analysis for 1F Grid Connected Load Conditions”, International Journal of Control Theory and Applications, vol. 10, pp. 23-32, 2017.

2016

Dr. K. Deepa and Yadava, A., “PV Array Based HERIC Inverter Topology for Irrigation Pump”, International Journal of Control Theory and Applications, vol. 9, pp. 197-203, 2016.

2016

R. George, M, S., and Dr. K. Deepa, “Implementation Of Wireless Charging System Using Single Stage Power Conditioning Circuit At Receiver”, International Journal of Control Theory and Applications, vol. 16, pp. 7939-7950, 2016.[Abstract]


Wireless transfer of electric power is being adopted as a viable method of charging portable devices as it makes them safer, raises their mobility and reliability and reduces the cost. Though efficient transmitter driver circuits and optimized coil designs have been developed by researchers in recent years, power conditioning at the receiver side haven’t got much attention. To reduce the number of components and the associated losses, the traditional two stage power conditioning should be replaced by an efficient and more compact single stage converter. This paper proposes an efficient wireless charging system based on resonant magnetic coupling that contains single stage boost rectifier at receiver. Single stage rectification and boosting is made possible by the bidirectional conduction ability of MOSFETs. The system is simulated in PSIM software, where overall power transfer efficiency is analyzed for different coupling factors, and different loads. The prototype of the entire system was developed in the laboratory by integrating coils and converters. The two fundamental concepts of power transmission, energy efficiency and transmission distance capabilities are analyzed and the results were found to be quite promising for practical use of this system

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2016

K. A. Lakshmypriya and Dr. K. Deepa, “100 kHz high voltage power supply for travelling wave tube”, International Journal of Control Theory and Applications, vol. 9, pp. 7187-7195, 2016.[Abstract]


Travelling Wave Tube (TWT) is a high gain microwave amplifier used in RADAR transmitters. TWTs require a highly sophisticated high voltage power supply for powering its electrodes viz., cathode and collectors. The high voltage power supply should have low output ripple and good regulation(few hundreds of millivolts) on cathode to obtain good RF performance and the power supply needs to be short circuit protected. This paper presents the high voltage power supply designed for a TWT based radar transmitter with electrode voltages of -9kV, -4.4kV and - 6.2kVDC. Input voltage of the high voltage power supply (HVPS) is 65VDC. The high voltage output is achieved with a series resonant converter operating at a high frequency of 100 kHz. The inverter output is stepped up by a high voltage high frequency transformer. The transformer output after rectification is filtered and fed to TWT. The output voltage is regulated using phase shift control. This work is further extended in the implementation of the designed high voltage power supply in hardware.

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2016

Dr. K. Deepa, “Design analysis and control of dc to dc quasi resonant converters”, Shodhganga : a reservoir of Indian theses @ INFLIBNET, 2016.[Abstract]


Pulse Width Modulation (PWM) based DC-DC converters are widely used in industrial applications such as DC motor drives, computer systems, aerospace systems and communication equipment. PWM converters operating at low frequency have certain drawbacks, primarily- increased size and weight of the power supplies. Also, since PWM converters are basically non-linear systems, they need to be averaged and linearized to obtain linear time-invariant models. Hence the design of high performance control for these converters is a challenging issue. More »»

2016

R. George, Sreekala, M., Dr. K. Deepa, S., D. S., S., D., and A., B. M., “Single-stage boost rectifier for wireless charging of portable devices through magnetic resonant coupling”, Advances in Intelligent Systems and Computing, vol. 394, pp. 443-452, 2016.[Abstract]


Advancements in power electronics have aided in the development of inductive power transfer technologies by providing transmitter coil drivers and converters for conditioning the power received at the receiver coil. But the use of traditional two-stage circuit with half wave or full wave rectifiers and boost converter at the receiver side may be inefficient, as it reduces the total power delivered to the load. As an alternative, single-stage boost rectifier can be used, which is compact and more efficient. This paper introduces an efficient wireless charging system based on resonant magnetic coupling that contains single-stage boost rectifier at receiver. Single-stage rectification and boosting is made possible by the bidirectional conduction capability of MOSFETs. The system is designed and simulated in PSIM software. The overall power transfer efficiency of the system is analyzed for different coupling factors of the inductive links and for different loads. © Springer India 2016.

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2015

P. Nair and Dr. K. Deepa, “Feed-Forward Control Algorithm for Hybrid Energy Systems”, Procedia Technology, vol. 21, pp. 575–580, 2015.[Abstract]


The paper presents a comparative analysis of the control strategies that can be used for hybrid energy systems. In the system considered, solar energy and battery are the two input sources to the DC-DC converter. Due to the intermittent availability of solar energy, a control circuit needs to be designed for the voltage regulation of the hybrid energy system. A single input fuzzy logic controller can maintain the output voltage constant for variations in either Photovoltaic (PV) or battery voltage only. Hence a control strategy is proposed in More »»

2015

S. Athira and Dr. K. Deepa, “Modified Bidirectional Converter with Current Fed Inverter”, International Journal of Power Electronics and Drive Systems, vol. 6, pp. 387-395, 2015.[Abstract]


A bidirectional dc-dc converter with multiple outputs are concatenated with a high frequency current source parallel resonant push pull inverter is presented in this paper. The two outputs are added together and it is taken as the input source for the inverter. The current source parallel resonant push pull inverter implemented here with high frequency applications like induction heating, Fluorescent lighting, Digital signal processing sonar. This paper proposes a simple photovoltaic power system consists of a bidirectional converter and a current fed inverter for regulating the load variations. Solar power is used as the input source for the system. Simulation of the proposed system is carried out in PSIM software and experimentally verified the results. © 2015 Institute of Advanced Engineering and Science. All rights reserved.

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2015

Dr. K. Deepa, Saju, H. Merin, and M Kumar, V., “Soft Switched Multi-Output Flyback Converter with Voltage Doubler”, International Journal of Power Electronics and Drive Systems (IJPEDS), vol. 6, no. 2, pp. 396–403, 2015.[Abstract]


A novel multi-output voltage doubler circuit with resonant switching technique is proposed in this paper. The resonant topology in the primary side of the flyback transformer switches the device either at zero voltage or current thus optimizing the switching devices by mitigating the losses. The voltage doubler circuit introduced in the load side increases the voltage by twice the value thereby increasing the load power and density. The proposed Multi-output Isolated Converter removes the need for mutiple SMPS units for a particular application. This reduces the size and weight of the converters considerably leading to a greater payload. This paper aims at optimizing the proposed converter with some design changes. The results obtained from the hardware prototype are given in a comprehensive manner for a 3.5W converter operating at output voltages of 5V and 3.3V at 50 kHz switching frequency. The converter output is regulated with the PI controller designed with SG3523 IC. The effects of load and line regulation for ±20% variations are analyzed in detail.

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2015

Dr. K. Deepa, Kurian, S. M., and M Kumar, V., “Improvement of efficiency in an active clamp ZVS multi-output flyback converter with voltage doubler by using UC3825 analog controller”, International Journal of Applied Engineering Research, vol. 10, pp. 1671-1686, 2015.[Abstract]


This paper proposes a voltage doubler for a multi-output active clamp ZVS flyback converter, aiming to achieve superior efficiency for low power applications which demand constant power supply. In order to increase the power packing density, a trouble-free control technique with analog controller UC 3825 is used to regulate the output voltage against load variations and supply disturbance. The design, operation and results of the proposed converter is explained in detail and analyzed. The guiding principles for component design are specified and confirmed. Investigational results obtained from a prototype of a 3.5W are presented. Performance assessment of the proposed converter with the existing topology is made and the conclusions derived are highlighted. © Research India Publications.

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2014

Dr. K. Deepa, Saju, H. Merin, and M Kumar, V., “High Efficiency Single Output ZVS–ZCS Voltage Doubled Flyback Converter”, Journal of The Institution of Engineers (India): Series B, pp. 1–8, 2014.[Abstract]


A switch operating at high switching frequency increases the switching losses of the converter resulting in lesser efficiency. Hence this paper proposes a new topology which has resonant switches [zero voltage switching (ZVS)] in the primary circuit to eliminate the above said disadvantages, and voltage doubler zero current switching (ZCS) circuit in the secondary to double the output voltage, and hence the output power, power density and efficiency. The design aspects of the proposed topology for a single output of 5 V at 50 kHz, its simulation and hardware results are discussed in detail. The analysis of the results obtained from a 2.5 W converter reveals the superiority of the proposed converter. More »»

2014

Dr. K. Deepa and M Kumar, V., “ZVS Multi-output Push-pull QRC Using Analog Controller UC3825 for Low Power Applications”, AASRI Procedia, vol. 7, pp. 62–67, 2014.

2013

Dr. K. Deepa, Jeyanthi, R., and M Kumar, V., “Analysis of a Quasi Resonant Switch Mode Power Supply for Low Voltage Applications”, International Journal on Electrical and Power Engineering, vol. 4, no. 2, pp. 85-92, 2013.[Abstract]


QRC provides efficient and regulated switch mode power supplies for robotic and satellite applications. This article addresses the enhanced controller techniques for high frequency isolation based push-pull Quasi Resonant Converter. This technique is similar to the conventional PI controller technique but varies only the enhancement constants to improve the time domain response of the converter. The proposed converter is designed for low output voltage and power rating, characteristically 5V and 5 W, with the comprehension of current design trends towards enhanced performance. At the primary stage, to validate the design of the converter, simulation is performed in PSIM for ±50% load variations. A prototype model of this converter is developed. The results obtained from the experimental set-up are presented, and analysed in detail. The results reveal the superiority of the proposed method. More »»

2013

Dr. K. Deepa, Kurian, S. Mary, and Vijaya, K. M., “Active Clamp Zero Voltage Switching Multiple Output Flyback Converter with Voltage Doubler”, International Review on Modelling and Simulations (IREMOS), vol. 6, no. 2, pp. 351–359, 2013.[Abstract]


This paper proposes a multi output zero voltage switching flyback converter topology with actively clamped switch and voltage doubler circuit. Flyback is the most popular topology for isolated power supply. It can provide multiple isolated outputs with a single switch and has lesser number of component counts. But it suffers from major drawback of high switch current stress high eddy current loss in the air-gap area, a large transformer core, and potential EMI problems. Now a day the latter is overcome by soft switching commutation techniques zero voltage switching (ZVS) or zero current switching (ZCS).But the device still suffers from excessive voltage stress. To triumph over these shortcomings an active clamp flyback converter is proposed. Here the active clamped switch introduced is turned on at zero voltage, this action discharges energy from active clamp capacitor to transformer leakage inductance that is then used to discharge capacitor across the switch thus bringing down voltage across the switch to zero before turn on. The capacitor also acts as clamp that avoids excessive voltage ringing across the switches. The proposed converter has a voltage doubler rectifier in the secondary. So no dissipative RC snubber across the diode is needed and thus high efficiency, low noise output voltage can be realized. The operating principle and analysis of proposed converter are discussed in this paper in detail. The closed loop simulation with fuzzy logic controller is also presented and the analysis of the converter in terms of efficiency and regulation are analysed in detailed.

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2013

T. Deepti, Dr. K. Deepa, and M Kumar, V., “Design and implementation of 30W DC-DC converter for Aerospace application”, International Review on Modelling and Simulations (IREMOS), vol. 6, pp. 323–328, 2013.[Abstract]


The DC-DC converter of a Spacecraft is one of the vital components of a satellite, which has a major role in ensuring the complete success of the mission. For providing a regulated voltage to various subsystems of satellites with variation in input voltage, DC-DC converter comes in picture. This paper presents the design and implementation of 30W flyback converter for providing supply for the telemetry tracking transmitter subsystem of the satellite. The input EMI filters responses and compensator for PWM UC1825 is simulated in MATLAB. The requirements for space applications are taken into consideration while designing and is successfully implemented. More »»

2013

A. Vijayan, Dr. K. Deepa, and M Kumar, V., “Soft Switching Scheme for a Post-Regulated Current-Fed Push-Pull Converter”, International Review on Modelling and Simulations (IREMOS), vol. 6, no. 2, pp. 317–322, 2013.[Abstract]


A high-efficiency post regulation method for a zero-voltage and zero-current switching (ZVZCS) current-fed push–pull converter is presented. An auxiliary transformer is incorporated as a post regulator. An additional voltage is either added or subtracted by the regulator to the output filter of the push-pull converter. An auxiliary regulator controls this transformer and it handles only a percentage of the total output power. Therefore, compared to a normal pre-regulator, higher efficiency is obtained. Since the converter is designed for high operational frequency the size and weight of the converter can be reduced and in order to reduce the switching losses, soft switching techniques have been employed. The remarkable feature of the paper presented is that zero voltage and zero current switching is not affected in any of the working conditions.

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2012

A. Sivaprasad, Mathew, K., and Dr. K. Deepa, “Power Factor Corrected Battery Charger for Electric Vehicle”, CiiT International Journal of Programmable Device Circuits and Systems’s, 2012.[Abstract]


Power electronic circuits comprising of AC-DC converters and DC-DC converters are Integral part of modern day electric vehicle. Batteries play a major role in a electric vehicle. Thus the selection and implementation of battery charger using DC-DC converter has important role in the development of electric vehicle. In addition to this, the existing battery chargers are without power factor correction which will affect the life and performance of the battery. So this paper presents a charging circuit for batteries used in electric vehicle with the concept of power factor correction. This paper emphasis the necessity for a boost converter for the power factor correction. Half bridge converter topology is implemented for battery charging purpose and it is simulated using MATLAB software with rectifier and boost circuit for verifying the improvement in power factor correction. The power factors and harmonic distortion obtained are presented and analysed in detailed.

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2012

Dr. K. Deepa, ,, Mamatha, I., and kumar, D. M. Vijaya, “Digital Simulation of SISO-ZVS-Push pull Quasi Resonant Converter for Different Loads”, International Journal of Engineering Research and Applications (IJERA), vol. 2, no. 4, pp. 896–901, 2012.

2012

S. .A, Dr. K. Deepa, and .Mathew, K., “Half bridge Converter for Battery Charging Application”, International Journal of Engineering Research and Applications (IJERA), vol. 2, no. 4, pp. 994–999, 2012.

2012

J. Marshal TP and Dr. K. Deepa, “Single Input DC-DC Converter for Hybrid Distributed Energy Generators with Maximum Utilization using DSP Controller”, International Journal of Engineering Research and Applications (IJERA), vol. 2, no. 4, p. 989–to, 2012.[Abstract]


Environmental friendly solutions are becoming more prominent than ever as a result of concern regarding the state of our deteriorating planet. This paper presents a new DSP controller based Switching configuration of hybrid Distributed Energy Generators (DER) with a single input DC-DC Buck-Boost converter, based on their availability. This configuration allows the two sources to supply the load separately or simultaneously depending on their availability. Because of its fast operation and reliability, DSP controller is used to improve the system efficiency at the most. Maximum amount of energy is extracted from the available source based on the control logic proposed in this paper. The system can operate in three different modes to obtain maximum efficiency based on the logic projected. The system is simulated using MATLAB/Simulink 2010a, the obtained results are also analyzed and presented in this paper.

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2011

Dr. K. Deepa, Gopi, A., Sebastian, J., Sathyan, A. M., K. Manaswin, S., and Shivapramod, M., “Design of PI Controller for Multi Output Boost Converter”, CiiT International Journal of Programmable Device Circuits and Systems’s, pp. 461–465, 2011.

2010

R. Jeyanthi, Dr. K. Deepa, and Amitkumar, K. S., “A comparative study of PI and Fuzzy Based Controllers for DC-DC converters”, CiiT International Journal of Programmable Device Circuits and Systems’s, pp. 20–28, 2010.[Abstract]


Industrial, residential and aerospace environments widely use switching mode power supplies. Switching modepower supplies need to be of small size as well as highly efficient. Hence a high switching frequency is necessary for reducing the size of the converter. But as the switching frequency increases, switching loss will also increase. This will result in gradual decrease in the efficiency of the power supplied. This paper is an attempt to study the application of fuzzy based control for DC-DC converters operating at finite switching frequency. Conventional PI method currently used for buck boost converters is compared with the fuzzy based control. Simulation results are also presented. The simulations show that the fuzzy control method has better dynamic performance.

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Publication Type: Conference Paper

Year of Publication Title

2017

Dr. K. Deepa, Kumar, P. A., Krishna, V. S., Rao, P. N. K., Mounika, A., and Medhini, D., “A Study of Comparative Analysis of Different PWM Techniques”, in 2017 International Conference On Smart Technologies For Smart Nation (SmartTechCon), 2017.[Abstract]


Multilevel inverter has benefits like low stress on switches, low harmonic distortion and can be used in high voltage and high power applications. In this paper 7 - level Multilevel inverter which has less number of switches is considered with various PWM Techniques. The different PWM techniques considered are Carrier-Overlap PWM(CO-PWM), Variable Frequency PWM(VF-PWM), Phase Shifted PWM(PS-PWM), Alternate Phase Opposition Disposition PWM(APOD-PWM), Phase Disposition PWM(PD-PWM), Phase Opposition Disposition PWM(POD-PWM). The given topology is modeled and simulated with the help of MATLAB/SIMULINK to check which PWM technique leads low THD value.

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2017

V. Sailaja, Dr. K. Deepa, A., S., P., R. E., and S., R. G. K., “Implementation of One Cycle Control for a Standalone System”, in International Conference on Trends in Electronics and Informatics, ICEI 2017, Tirunelveli, India , 2017.[Abstract]


The converter used in this paper is Double Input Isolated Flyback Converter which is more efficient in multi input and multi output systems. The control method adopted in this paper is One Cycle Control. The feasibility of the converter with this control is checked. The circuit has been simulated in MATLAB software and analysis performed are presented.

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2017

Dr. K. Deepa, Baig, M. F., Mohith, P., and Abhinav, A. V., “Dynamic Analysis of LUO Converter with all Parasitics”, in 2017 International Conference on Trends in Electronics and Informatics (ICEI), 2017.[Abstract]


This paper presents the ripple free voltage from the design of developed DC-DC converter model. DC voltage provided by battery is not a constant voltage and contains high voltage ripples, thus it is not suitable for most the applications like electric vehicle. Closed loop DC-DC converters are employed to eliminate the ripples regardless of change in the voltage across the load. In the existing method, the classical converter for electric vehicle applications do not meet the load requirements. To eradicate this problem the advanced DC-DC Luo-converter technology was introduced. In this paper the state space averaging technique is applied for Luo converter. The simulation in MATLAB/Simulink was carried out and the result obtained for the circuit and state space model are presented.

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2017

P. P. Reddy, Suresh, P. V. B., P. Reddy, T., Manitha P. V., and Dr. K. Deepa, “Remote Control of an Electronic Device Using EOG”, in International Conference on "Smart Technologies for Smart Nations(Smart Techcon 2017), Bangalore, India, 2017, pp. 780-783.[Abstract]


Over 1 billion of the world population have some form of disability which corresponds to 15% of the world population. And this disability suppresses their ability to communicate with the physical world. The proposed prototype provides an opportunity for such people to be self-reliable and enhances the ability of the disabled people to operate the electrical and electronic devices remotely, without the assistance of fellow beings. This prototype aims at providing an eminent platform for disabled people to communicate with the physical world at an equitable price. Human eye is capable of producing a corneo-retinal potential whose magnitude varies from 0.4-1mV with a frequency ranging from 0-35 Hz. This is attributed to the high metabolic rate of retina. The proposed model exploits this appealing property of human eye. It encompasses the ECG electrodes to trap this potential and is fed as an input to the amplifier circuit. Further, the amplified signal is conditioned using a signal conditioning circuit to remove the noise creeping into the signal. This is wirelessly transmitted using an RF module to the receiver circuit and from there it is used to trigger the required circuit. A LED is triggered to ensure the functionality of the framework.

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2017

N. M. Ibrahim, Gangadhar, J. V., Partho, M., and Dr. K. Deepa, “High frequency SEPIC-WEIBERG converter for space applications”, in Proceedings of the International Conference on Inventive Computation Technologies, ICICT 2016, 2017, vol. 2.[Abstract]


SEPIC-WEINBERG converter is introduced in this paper. This converter is ideal for photovoltaic applications. The suggested converter has efficiency higher than that of regular SEPIC and Weinberg converter. But the SEPIC-WEINBERG converter has similar levels of switch voltage stress as that of the SEPIC. The switching losses are low in the suggested converter. It is of small size and has low current harmonic content in it. The analysis of the SEPIC-WEINBERG converter is done and discussed in depth. © 2016 IEEE.

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2015

V. Anuvinda and Dr. K. Deepa, “Fuzzy based flexible converter for satellite electronics”, in Circuit, Power and Computing Technologies (ICCPCT), 2015 International Conference on, Nagercoil, 2015.[Abstract]


Single module DC-DC converter apt for two applications of same power and different output voltages is proposed with its relevant simulation results to substantiate the converter working. The suggested multi output flexible converter provides a provision to select one among the four available output combinations. The selection of required output combination is done merely with the help of output connectors, without changing any circuit parameters. A simulation model of the converter with one of the four combinations is done in MATLAB Simulink. Turn on at zero voltage for active devices, and turn off at zero current for passive devices are accomplished because of the associated LLC resonance principle. A fuzzy controller is also introduced for zero voltage regulation of the converter for change in load current. More »»

2015

S. Sreelakshmi and Dr. K. Deepa, “Fuzzy based bidirectional converter”, in Circuit, Power and Computing Technologies (ICCPCT), 2015 International Conference on, Nagercoil, 2015.[Abstract]


The core topic of the paper discuses bidirectional buck/boost converter implemented using soft switching. In addition to a soft switched DC-DC conversion, the
circuit also facilitates an additional output which makes the system capable of supporting multiple applications. The circuit under discussion uses fuzzy logic for the closed loop
operation which has better overall performance compared to other conventional converters The circuit has been simulated in Mat lab Simulink software and analysis of both the

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2015

P. Nair and Dr. K. Deepa, “Two-port DC-DC converter with flyback inverter for rural lighting applications”, in Advancements in Power and Energy (TAP Energy), 2015 International Conference on, Kollam, 2015, pp. 249-253.[Abstract]


A two port DC-DC converter, combined with a modified flyback inverter, is presented in this paper. The output of the inverter is 230V sinusoidal voltage at 50Hz used for supplying rural lighting applications. Combination (solar and battery) of the energy sources along with a voltage doubler forms the two input port of the DC-DC converter for solar-battery hybrid systems. To obtain a low frequency output voltage for the load modified flyback inverter structure is utilized. A control algorithm implemented to supply the load using PV and battery sources either independently or simultaneously for maintaining the constant output voltage is also presented. This work focuses on simulation studies of the same to verify the converter working using PSIM software.

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2014

N. K., V. Sailaja, Dr. K. Deepa, and Manjunath, H. V., “A DC-DC multi output SEPIC converter for suburban power application”, in International Conference on Electronics, Communication and Computational Engineering, ICECCE 2014, 2014.[Abstract]


Non conventional sources of energy are those which are depleting day by day. Solar energy which is abundant in India has gained more importance hence. The energy produced by the sun, is harnessed with the help of PV panels and injected to converters and rectifiers. It is subsequently fed to an inverter that produces an AC power. In this paper, a PV panel fed modified dual output SEPIC converter is proposed. Dual outputs obtained from the modified multi output SEPIC converter is used to charge two batteries which in turn are fed to the cascaded multilevel DC/AC inverter. The simulation analysis of the system proves that it is well suited for both resistive and inductive loads; hence it is proposed for driving a motor load in rural areas agricultural applications. This system can be deployed in areas where grid connection is not possible such as in isolated or rural areas.

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2014

Dr. K. Deepa, Jeyanthi, R., Mohan, S., and M. Kumar, V., “Fuzzy Based Flyback Converter”, in 2014 International Conference on Advances in Electrical Engineering (ICAEE), 2014.[Abstract]


DC-DC converters can be viewed as dc transformers that deliver a DC-DC voltage or current at a different level than the input source. The unregulated DC voltage is converted into regulated DC voltage at required level under varying load and input voltage condition. The control of output voltage is performed in a closed loop using the principle of negative feedback.The fuzzy logic controller for DC-DC converters i.e. Fly-Back Converter offers an alternative way to implement a central action that exploits the inherent variable structure nature of converter. The controller acts fast to changes in the converter output voltage producing good load regulation. This control technique offers converter stability for robustness, good dynamic response and implementation is simple. Hence, this paper is the result of an attempt to design aDC-DC Fly-Back Converter and an FLC for the same. The paper also draws a comparison between a conventional PI and fuzzy controllers for the aforementioned converter.

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2014

K. Nayana, Sailaja, V., Dr. K. Deepa, and Manjunath, H. V., “A DC-DC multi-output SEPIC converter for suburban power application”, in Electronics, Communication and Computational Engineering (ICECCE), 2014 International Conference on, Hosur, 2014.[Abstract]


Non conventional sources of energy are those which are depleting day by day. Solar energy which is abundant in India has gained more importance hence. The energy produced by the sun, is harnessed with the help of PV panels and injected to converters and rectifiers. It is subsequently fed to an inverter that produces an AC power. In this paper, a PV panel fed modified dual output SEPIC converter is proposed. Dual outputs obtained from the modified multi output SEPIC converter is used to charge two batteries which in turn are fed to the cascaded multilevel DC/AC inverter. The simulation analysis of the system proves that it is well suited for both resistive and inductive loads; hence it is proposed for driving a motor load in rural areas agricultural applications. This system can be deployed in areas where grid connection is not possible such as in isolated or rural areas. More »»

2014

S. Athira and Dr. K. Deepa, “Solar powered ultrasonic cleaner”, in Emerging Research Areas: Magnetics, Machines and Drives (AICERA/iCMMD), 2014 Annual International Conference on, Kottayam, 2014.[Abstract]


A Dual output half bridge converter combined with a resonant parallel fed inverter for ultrasonic cleaner is presented in this paper. The output of the inverter is 230V sinusoidal voltage with high frequency (28kHz) for ultrasonic cleaner applications. To obtain better load regulation PI controller is incorporated with the system for regulating 20% of load change. The simulation is carried out for a 58W power application. Solar power is used as input for the converter and output of the converter acted as the input for the inverter. More »»

2014

Dr. K. Deepa, Padmaja, P. J., and M Kumar, V., “Cascoded multi output push-pull converter”, in 2014 International Conference on Advances in Electrical Engineering, ICAEE 2014, Vellore, Tamilnadu, 2014.[Abstract]


<p>Multi-output DC-DC converters are widely used in many applications such as military, communication automobile, space application etc.. The DC-DC converters which is used for aerospace applications, has important role in ensuring the complete success of the mission. DC-DC converter is used for providing a regulated voltage to various subsystems of satellites with variation in input voltage and output resistive load. Different types of DC-DC converters were analyzed and out of all DC-DC converters, push-pull converter achieves tight regulation in the output voltage, So a push-pull converter for low power is designed for providing regulated power supply to the spacecraft. This paper deals with the design and closed loop implementation details of cascoded multi output push-pull converter with PWM controller IC (UC 3825). The results obtained in simulation and hardware implementation is presented and analyzed in detail for 9W, 50 kHz laboratory prototype developed. © 2014 IEEE.</p>

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2014

T. P. Marshal and Dr. K. Deepa, “Hybrid renewable energy system: Optimum design, control and maximum utilization with SIBB converter using DSP controller”, in Power and Energy Systems Conference: Towards Sustainable Energy, 2014, 2014.[Abstract]


Global warming and the shortage of fossil fuels increase the usage of renewable energy resources to satisfy the future energy demand of our depleting planet. This paper presents an innovative Switching logic for hybrid Distributed Energy Generators (DEG) by using a Single Input Buck-Boost (SIBB) converter and DSP controller based on their availability. With this proposed logic maximum amount of energy is extracted from the renewable energy resources depend on their availability. The combination of suggested switching logic and circuit configuration allows the two renewable energy resources, to supply the load individually or simultaneously based on the availability. The fast operation and reliability of DSP controller is utilized to increase the efficiency of the proposed system at the most. At any given instant to achieve extreme system efficiency three different modes of operations are projected. To analyze the real time feasibility of this logic the system is simulated by using MATLAB/Simulink 2010a; and the obtained results are studied and presented in the past. In laboratory a hardware model of the system is developed along with integrating the switching logic proposed for the learning of system in contradiction of the real world conditions. The results attained are discussed and presented in this paper.

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2013

Dr. K. Deepa, Deepti, T., and Kumar, V., “New multi-output switching converter with low drop out post regulator”, in Emerging Trends in Communication, Control, Signal Processing & Computing Applications (C2SPCA), 2013 International Conference on, Bangalore, 2013.

2013

Dr. K. Deepa, Vijayan, A., and M Kumar, V., “Closed loop controlled solar fed post regulated push-pull converter”, in Control Communication and Computing (ICCC), 2013 International Conference on, Thiruvananthapuram, 2013.[Abstract]


A solar fed push-pull converter employing post regulation method with soft commutated switches is discussed in the paper. Incorporating an inductor in series with the source the converter operates as a current fed one. The post regulation is carried out with an auxiliary current transformer. The post regulation technique utilizes the Transformer Turns Ratio Regulator concept which adds or subtracts voltage to the output of the push-pull converter. A boost converter is incorporated at the secondary side of the transformer and a current is fed to the input of the converter. The amount of current fed is controlled by the regulator circuit which handles only a percentage of the total output power. The power handling capacity of the load is enhanced with an improvement in efficiency and regulation. The size and weight of the converter is reduced by suitably selecting higher switching frequencies. In order to reduce the switching losses, zero voltage and zero current switching (ZVZCS) have been employed. The remarkable feature of the paper presented is that the soft switching is not affected by load variations. This is discussed in detail with resonant waveforms, output waveforms and efficiency curves. More »»

2013

Dr. K. Deepa, Saju, H. Merin, and M. Kumar, V., “Soft switched flyback converter for SMPS applications”, in Control Communication and Computing (ICCC), 2013 International Conference on, Thiruvananthapuram, 2013.[Abstract]


Isolated converters find wide application in SMPS, telecommunication, rectifiers etc. Among these topologies flyback converter is best opted for SMPS applications due to its simplicity in design, operation and less component count. High frequency dc-dc converters are subjected to high switching losses hence an auxiliary switch is designed to perform soft switching in main switch. The devices used in the converter are operated either in ZVS or ZCS to reduce the switching loss of the converter. This improves the converter performance. The converter designed is simulated, realized and presented in detailed for a laboratory model of 1.08W, 3.3V, 50 kHz.

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2013

Dr. K. Deepa, Padmaja, P. J., and Kumar, V., “PWM closed loop controlled multi-output push-pull converter”, in Control Communication and Computing (ICCC), 2013 International Conference on, 2013.[Abstract]


The DC-DC converter of a spacecraft is one of the basic components of a satellite, which has important role in ensuring the complete success of the mission. For providing a regulated voltage to various subsystems of satellites with variation in input voltage and output resistive load, DC-DC converter is used. This work presents a brief idea about the study, design and implementation of push-pull converter, PWM controller and lag-lead controller. The various topologies for DC-DC converter are studied and out of all DC-DC converters, push-pull converter is the one which can achieve tight regulation on the output voltage. So a push-pull converter for low power is designed for providing regulated power supply to the telemetry tracking transmitter subsystem in satellite. This work deals with the design and implementation details of multi output push-pull converter with PWM controller IC (UC 3825). The results obtained in hardware implementation is presented and analyzed in detail for 7W, 50 kHz laboratory prototype developed. More »»

2013

Dr. K. Deepa, R Lakshmi, M., ,, and M. Kumar, V., “Bi-directional push-pull converter fed four quadrant DC drive”, in Emerging Trends in Communication, Control, Signal Processing & Computing Applications (C2SPCA), 2013 International Conference on, Bangalore, 2013.[Abstract]


The DC-DC converter find a wide scope in industries, telecommunication sectors, power electronics area, etc.. Nowadays bi-directional converters have a higher end over them since the energy from the load during regenerative braking is fed back to the source, thus obtaining energy efficient system. In this paper a bi-directional push-pull DC-DC converter is proposed for a four quadrant DC drive application. A laboratory prototype of 5W bi-directional push-pull converter was designed, developed and realized and is presented in detail.

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2012

Dr. K. Deepa and Vijayakumar, M., “An Improved Push-Pull Converter with ZVS-ZCS in Active and Passive Switches for Low Voltage Applications”, in International conferences on Control System and Power Electronics – CSPE 2012, 2012, vol. 2012, pp. 240–245.

2012

Dr. K. Deepa, Jeyanthi, R., and M Kumar, V., “Efficient and compact power supply for robotic application”, in IET Conference Publications, 2012, vol. 2012, pp. 61-65.[Abstract]


Robots require compact, power efficient and regulated power supplies for their efficient operation. This paper deals with the problem of developing such a power supply. A single-output zero voltage switching pushpull converter with low switching and conduction losses for robotic applications has been presented in this paper. The proposed converter is designed for outputs of 5 V/1 A with a switching frequency of 50 KHz. A prototype model of this converter is developed and was used to power a dc servo motor of 5V/1A/0.5Nm/950rpm. The results obtained from the experimental set-up are presented and analysed in detail. The results reveal the superiority of the proposed method.

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2012

Dr. K. Deepa and M Kumar, V., “Performance analysis of a DC motor fed from ZCS-quasi-resonant converters”, in Power Electronics (IICPE), 2012 IEEE 5th India International Conference on, Delhi, 2012.[Abstract]


This paper presents a comparative study of the ZCS-QRC fed Dc servo drive at various switching frequencies such as 100kHz, 50kHz and 10kHz. The significant characteristic of QRC is that the switching devices can be either switched on at zero voltage or switched off at zero current, so that switching losses, stresses are low and volume is reduced moreover power density is high. These features increase the efficiency of the converters. The regulation of QRC is achieved by varying the switching frequency of the converter. Hence, called Frequency modulated Zero current switching quasi resonant converter. This paper reports the simulation and hardware implementation of DC Servo motor fed from ZCS-QRC in half wave and full wave modes.

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2012

Dr. K. Deepa, Sharika, M., and M Kumar, V., “Implementation of a new multi output push-pull primary ZVS converter”, in India International Conference on Power Electronics, IICPE, Delhi, 2012.[Abstract]


<p>This paper introduces a new multi-output push-pull primary Zero Voltage Switching Converter (ZVS) in continuous conduction mode. Theoretical analysis and design methodology for a 5W, 50 kHz laboratory prototype push-pull ZVS are discussed in this paper. Simulation of the proposed circuit was carried out with PSIM software and the results obtained are analogous to the results obtained from hardware prototype. Both the results are presented and analysed. The proposed new converter is suitable for communication, automobile, computer and aerospace applications to supply power to more loads. The necessity of more than one single output converters is reduced by this proposed multi output converter. © 2012 IEEE.</p>

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2012

T. Deepti, Dr. K. Deepa, and Chandran, S., “Implementation and comparison of a new MOC with post regulators”, in India International Conference on Power Electronics, IICPE, Delhi, 2012.[Abstract]


<p>A comparative study of two different types of post regulators is carried out in this paper. First one is low drop out post regulator (LDO) and second one is DC-DC step down LTM 4601 HV post regulator. These post regulators regulate the auxiliary high power output of the multi-output flyback dc-dc converter, designed for providing supply for the telemetry tracking transmitter subsystem of the satellite. The requirements for space applications are taken into consideration while designing. © 2012 IEEE.</p>

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2012

Dr. K. Deepa, Sharika, M., and M Kumar, V., “Implementation of a SISO-ZVS push-pull converter fed DC servo motor”, in India International Conference on Power Electronics, IICPE, Delhi, 2012.[Abstract]


<p>A single-output zero voltage switching push-pull converter with low switching and conduction losses for robotic applications is presented in this paper. The proposed converter is designed for output of 5 V/ 1 A with a switching frequency of 50 kHz to drive a DC servo motor used in robots. The proposed converter is compact since high switching frequency of operation is chosen. Resonant technique added to the converter reduces the switching stress, losses and thereby increases its efficiency. A prototype model of this converter is developed and the hardware is implemented. The results obtained from the experimental setup are analyzed in detail. The results reveal the superiority of the proposed method. © 2012 IEEE.</p>

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2011

Dr. K. Deepa, Savitha, P., and Vinodhini, B., “Harmonic analysis of a modified cascaded multilevel inverter”, in 2011 1st International Conference on Electrical Energy Systems, ICEES 2011, Chennai, Tamilnadu, 2011, pp. 92-97.[Abstract]


In Multilevel Inverters, Cascaded H bridge converters are considered to be the most preferred form of converters. But in these converters as the number of staircase levels in output voltage increases the dc source requirement also increases, thereby limiting its application. This paper tries to address the above mentioned problem by developing a Modified version of Cascaded Multilevel Converters which require reduced number of dc voltage source for increased levels in output voltage as compared to conventional cascaded converters. The spectral quality analysis of output voltage obtained for different loads is also shown signifying the merits of modified converters. Due to these advantages the drawback in the implementation of conventional cascaded converters in electric vehicles or in industrial applications is overcome by modified cascaded inverters. In this paper, the developed Modified Cascaded Converters are simulated in MATLAB/ SIMULINK and the THD of different output voltage levels are compared for different loads. © 2011 IEEE.

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2010

J. R, Dr. K. Deepa, and selvi, A., “PI/EPI/FUZZY Controller Approach for a 100kHz Single Hard Switched Buck-Boost Converter”, in International Conference On Intelligent Design and Analysis of Engineering Products, Systems and Computation, 2010.

2005

S. Arulselvi, Dr. K. Deepa, and Uma, G., “Design, analysis and control of a new multi-output flyback CF-ZVS-QRC”, in Industrial Technology, 2005. ICIT 2005. IEEE International Conference on, 2005.

Publication Type: Book

Year of Publication Title

2005

Dr. K. Deepa, Zamrooth, D., and Porselvi, T., Electrical Machines, vol. 1. Scitech publications, 2005.

2003

Dr. K. Deepa, porselvi, porselvi, and sangeetha, tresa, Control Systems, vol. 1. Charulatha publications, 2003.

Funds Recieved

No. Year Topic / title Position held Details
1. 2013-2014 B.Tech student Project titled “Grid connected photovoltaic system” Project Guide Funded Rs 4,500 by Karnataka state council for science and technology, Bangalore, 37th series of student project’s program (SPP), 2013 -2014, Reference no  :- 37S1015.
2. 2015 IEEE PES student Branch Chapter in Amrita School of Engineering startup fund IEEE –PES student Chapter Advisor Initiated IEEE PES student Branch Chapter in Amrita School of Engineering and received a startup fund of $120.
3. 2015 IEEE PES & IAS Joint student Branch Chapter startup fund of $500. IEEE –PES & IAS Jt student Chapter Advisor Initiated IEEE PES & IAS Joint student Branch Chapter in Amrita School of Engineering and received a startup fund of $500.
4. 2016 High performing student branch IEEE PES award - 2015 IEEE –PES & IAS Jt student Chapter Advisor Received $295 as high performing student branch IEEE PES award - 2015
5. 2017 High performing student branch IEEE PES award - 2016 IEEE –PES & IAS Jt student Chapter Advisor Received $401 as high performing student branch IEEE PES award – 2016, First in India and Region 10 – Asia Pacific. (Advisor role).
6. 2017 IEEE IAS CMD Chapter Web Contest  IEEE –PES & IAS Jt student Chapter Advisor Award of $700 for 2nd prize in IEEE IAS CMD Chapter Web Contest 
7. 2017 CMD Outstanding Chapter Contest IEEE –PES & IAS Jt student Chapter Advisor Award of $850 for winning IEEE IAS CMD outstanding joint Chapter award 

Keynote Delivered

  • Dr. K. Deepa was invited to deliver a key note address on "Battery Management System in Electric Vehicles", for IEEE technically sponsored first international conference on power, energy, control and transmission systems 2018 organized by Department of EEE at Sri Sairam Engineering College, Tambaram, Chennai on 23rd February 2018. And also she chaired a session in the conference.

PhD Students

  • Ms.Thiruvonasundari (Part time)
    Department of EEE
    Area of research: Battery Management System
    Registered on August 2016
  • Ms.M.Raichel Ruby (Part time)
    Department of EEE
    Area of research: Power Quality
    Registered on August 2016
  • Mrs.T. Deepti (Full time)
    Department of EEE
    Area of research: Power Converters
    Registered on July 2017