*Professor K. Gopakumar*

Professor

Department of Electronic Systems Engineering ( Formerly CEDT)

Indian Institute of Science (IISc)

Bangalore 560012

Email : kgopa@iisc.ac.in

Phone : +91 80 23600810 Ext 234 (off.)

Mobile : +91-9448227853

Fax : 080-22932290, 080-23600808

Dr. K. Gopakumar received his B.E. (Electrical Engineering) degree from Indian Institute of Science in 1980. Later on he did his M. Sc. (Engg.) (E.E.) in 1984 and Ph.D. (E.E.) in 1994 both from the Indian Institute of Science respectively. His thesis title for M.Sc. was “A Series Dual Current Source Inverter fed Split-Phase Induction Motor Drive” and thesis title for Ph.D. was “Study on Voltage Source Inverter fed Drives for Induction Motor with Split Phase Windings”.

Dr. Gopakumar is currently a Professor at the Department of Electronic sytems Engineering( formerly CEDT- Centre for Electronics Design and Technology (CEDT), at Indian Institute of Science (IISc), Bangalore, India. He is also the member of the following professional bodies :-

- Fellow IEEE
- Fellow IETE (India)
- Fellow Indian National academy of Engineers (FNAE)
- Co Editor-in-Chief IEEE Trans. On Industrial Electronics.
- IETE (India)- B.K Bose award for contributions to the area of power electronics and drives for high power applications
- Distinguished Lecturer-IEEE Industrial Electronics Society
- IISc Alumni award for Excellence in Research in Engineering-2016
- ABB Chair professor 2016 -2018
- IEEE IE Eugene Mittelmann achievement award-2019
- Honorary PhD( Doctor Honoris Causa) By Lublin University of Technology, Poland

**Professional Experience – 27 years**

1984-1987: During this period, Dr. K. Gopakumar was employed by the Indian Space Research Organisation, Satellite Centre, Bangalore, India. The nature of the work was to design and develop satellite on board power supply systems. During this period he was fully involved in the design, development and testing of the SROSS-1 (Stretched Rohini Satellite Series-1) main power supply systems (switched mode power supply systems) for the controls and payloads.

From 1987 onwards: employed at CEDT, Indian Institute of Science, Bangalore, India.

- 1987 to 1993: Scientific Officer,
- 1993 to 1997: Senior Scientific officer,
- 1997 to 2003: Assistant Professor
- 2003 to 2007: Associate Professor
- 2007 onwards: Professor

### Major M.Tech. Projects

**Multiple outputs switched mode power pack**– A compact general-purpose power supply with feedback control is designed and developed, using power MOSFETS. Output power is 50 watts and the converter switching frequency is 50kHz.**PWM current source inverter drive**– A four-quadrant converter is designed for a 5HP induction motor drive. This involved the design and development of front-end phase controlled converter, current source inverter using thyristors and the necessary PWM closed loop control circuits.**A PWM drive for a high speed PCB drilling machine**– A compact 1kHz output frequency PWM inverter is designed and developed, using power MOSFETs, for a 150 watts, 50,000rpm PCB drilling motor.**AC servo drive – power circuit**– A front-end controlled converter for inverter drive applications is designed and developed.**110 volt, PWM inverter for railways**– A 2kw MOSFET based PWM inverter is designed and developed with necessary control circuit and the output filters for the sine wave operation. The input to the inverter is battery and a controlled voltage booster stage is also developed.**A field oriented controlled inverter drive for induction motor using DSP -AD 2105**– A digital control card for a vector-controlled drive is developed. Inputs to the card are the speed reference signal, speed feed back signal, motor voltage and current signals. Appropriate speed and current control loops and the vector rotator algorithms are implemented and the controller card will output the required inverter PWM signals.**A general purpose V/f drive using flux computation from terminal measurements**– The general purpose PWM card is developed using 80 C 196 microcontroller. Space phasor based PWM for variable speed operation is implemented with appropriate protection circuits.**A space phasor based PWM inverter drive using single chip micro controller**– This is a continuation of the above-mentioned project for extending the motor operation in the over modulation region, without any transients.**A multi Axis space Phasor Based PWM Current Hysteresis Controller for V/f drive**The aim is to develop a simple space phasor based current hysteresis controller for V/f drive using DSP chip, for an IGBT based inverter.**A sensorless vector control scheme for induction motors using a space phasor based current hysteresis controller**

### Major Consultancy Projects

Design and Development activities at CEDT are always according to the industrial requirements and as a result Dr. K. Gopakumar has associated with the following consultancy projects.

**A four quadrant digital controller design for a DC drive**Consulting firm – NGEF Ltd. -Duration (Oct. – 93 to June – 95) The task was to design and develop, the speed and current control loop, converter control circuit for four quadrant operation, field converter control circuit and the monitoring and protection circuit**Sensorless speed control of induction motor**– Consulting firm – Infosys Technologies Ltd. (July – 94 to Aug. – 95) The task was to give technical advise on a high performance drive control scheme using terminal voltage and current measurements only**General purpose power converter, controller using single chip microcontrollers**. Consulting firm – BHEL. (Aug. – 93 to May – 95). The task was to design and develop a converter control circuit using 80C 196 microcontroller**AC variable speed drive**– Consulting firm – JVS Electronic Ltd. (Oct. – 94 – Mar. – 96). The task is to give design details, including the appropriate circuit diagrams for a 5hp induction motor inverter power circuit and the controllers**Variable frequency AC drive for induction motor. – IPA Pvt. Ltd.**(Nov. – 94 – Mar – 96) The task is to design and develop a variable speed induction motor inverter drive control and protection circuits**3KVA on line UPS. – Foresight Power Systems Pvt. Ltd.**(Feb. – 95 -Apr. 96). This involves the design and development of the battery charger, inverter and the filter circuits with appropriate control and protection circuits.**Feasibility study for Electric Three – Wheeler Vehicles. DASAG Energy Engineering Ltd. Seuzach, Switzerland, – (Jan. – 96)****A Regenerative Electronic load**; Here the three phase out put is rectified and then fed to the mains through a phase controlled converter in the inversion mode. The project is completed and is funded by the Department of electronics, Govt. of India.**Studies on Multi level inverter fed Induction motor drive schemes with common mode voltage elimination for Induction motor drives**: Department of Science and Technology-2004**Control and drive developments for a four wheeler EV**: Development of the DSP platform and design and development of a sensorless field oriented control algorithm for the induction motor drive: the project is funded by General Motors, USA-June-2005**A five-level inverter scheme with common mode voltage suppression and DC link capacitor balancing for induction motor drives for high power applications by cascading two-level an dthree-level inverter structures-**:Department of Science and Technology-2006-20Lakhs**A multi-level 12-sided polygonal voltage space vector structure for high power induction motor drive applications by cascading the conventional two-level and three-level inverters.**: – Department of Science and Technology-2008.-30lakhs**Design and development of a three-level inverter for aircraft applications-**: Honeywell India- Rs.15 Lakhs

### List of Publications – Journal

- A general Multilevel Polygonal Space Vector Generation scheme with reduced switching for the inverter and harmonic suppression using a switched-capacitive filter for the full modulation range,R. Dewani, K. Gopakumar, U. Loganathan and S. Bhattacharya,
**accepted in IEEE Transactions on Power Electronics, doi: 10.1109/TPEL.2022.3152497**. - A single D.C. link Multi-level 42-sided polygonal Voltage Space Vector Generation with lower order harmonic suppression using Switched-Capacitive filter, R. Dewani, K. Gopakumar, U. Loganathan, L. G. Franquelo and K. Rajashekara,
**accepted in IEEE Transactions on Industrial Electronics, doi: 10.1109/TIE.2021.3128921.** - A Ten Level Inverter Fed Drive Scheme with Extended Linear Modulation Range,Souradeep Pal;Mriganka Ghosh Majumder;Rakesh R;K. Gopakumar;Umanand Loganathan;Mariusz Malinowski;Dariusz Zielinski,
**accepted in IEEE Transactions on Industrial Electronics, doi: 10.1109/TIE.2021.3134055.** - A Multilevel Inverter with Inherent Common Coupling Point Voltage Balancing of Stacked Capacitors across a Single DC-Link for Induction Motor Drives, Tutan Debnath;Rakesh R;Mriganka Ghosh Majumder;Mohammed Imthias;K. Gopakumar;Umanand Loganathan;Leopoldo Garcia Franquelo,
**accepted in IEEE Transactions on Industrial Electronics, doi: 10.1109/TIE.2021.3137443**. -
A Dense Multilevel 30-Sided Space Vector Generation Using a Single DC Link for an Induction Motor Drive,R. R, M. G. Majumder, K. Gopakumar, L. Umanand, C. Cecati and D. Zielinski,
**IEEE Transactions on Power Electronics, vol. 36, no. 10, pp. 11681-11690, Oct. 2021, doi: 10.1109/TPEL.2021.3070078.** - A Very High Resolution 30-Sided Space Vector Generation from a Single DC-link for Induction Motor Drives:Rakesh R;Mriganka Ghosh Majumder;Rahul Dewani;K. Gopakumar;Umanand Loganathan;Wojciech Jarzyna;Leopoldo Garcia Franquelo:
**IEEE Transactions on Industrial Electronics, vol. 69, no. 1, pp. 160-168, Jan. 2022, doi: 10.1109/TIE.2021.3053884** - A Fault Tolerant Five-Level Inverter Topology with Reduced Component Count for Open-End IM Drives :Mriganka Ghosh Majumder;Rakesh R;K. Gopakumar;Loganathan Umanand;Kamal Al-Haddad;Wojciech Jarzyna;
**IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 9, no. 1, pp. 961-969, Feb. 2021** - Suppression of Lower Order Harmonics for the full modulation range for a 2-level inverter fed IM drive with a switched capacitive filter technique forming a 42-sided Voltage Space Vector Structure;Rahul Dewani;Rakesh R;K. Gopakumar;Umanand Loganathan;Dariusz Zielinski;Leopoldo Garcia Franquelo;
**IEEE Transactions on Industrial Electronics, vol. 68, no. 8, pp. 6701-6709, Aug. 2021, doi: 10.1109/TIE.2020.3007079.** - A Multilevel 30-sided Space Vector Structure with Congruent Triangles and Timing Calculation using only Sampled Reference Voltages ;Rakesh R;Mriganka Ghosh Majumder;K. Gopakumar;Umanand Loganathan;Dariusz Zielinski;Wojciech Jarzyna;Kamal Al-Haddad ;
**IEEE Transactions on Industrial Electronics, vol. 68, no. 9, pp. 7884-7894, Sept. 2021, doi: 10.1109/TIE.2020.3013527** - A Cascaded Nine-Level Inverter Topology With T-Type and H-Bridge With Increased DC-Bus Utilization :Souradeep Pal;Mriganka Ghosh Majumder;R. Rakesh;K. Gopakumar;Loganathan Umanand;Dariusz Zielinski;Abdul R. Beig:
**in IEEE Transactions on Power Electronics, vol. 36, no. 1, pp. 285-294, Jan. 2021** - Extending the Linear Modulation Range to Full Base Speed Independent of Load Power Factor for a Multilevel inverter fed IM Drive Mriganka Ghosh Majumder ; Rakesh R ; Imthias Mohammed ; K. Gopakumar ; Umanand Loganathan ; Wojciech Jarzyn
**IEEE Transactions on Industrial Electronics, vol. 67, no. 11, pp. 9143-9152, Nov. 2020** - A Switched Capacitive Filter based Harmonic Elimination Technique by Generating a 30- Sided Voltage Space Vector Structure for IM Drive Rakesh R ; Krishna raj R ; Apurv Kumar Yadav ; K. Gopakumar ; Umanand Loganathan ; Kouki Matsuse GAE;
**IEEE Transactions on Power Electronics, vol. 35, no. 3, pp. 2402-2410, March 2020** - A Five-Level Inverter Scheme Using Single DC Link with Reduced Number of Floating Capacitors and Switches for Open-End IM Drives:Mriganka Ghosh Majumder ; Apurv Kumar Yadav ; K. Gopakumar ; Krishna Raj R ; Umanand Loganathan ; Leopoldo Garcia Franquelo:
**IEEE Transactions on Industrial Electronics, vol. 67, no. 2, pp. 960-968, Feb. 2020** - Minimization of Switched Capacitor Voltage Ripple in a Multilevel Dodecagonal Voltage Space Vector Structure for Drives

Mohammed Imthias, Student Member, IEEE, Krishna Raj R, Student Member, IEEE, Apurv kumar Yadav, Student Member, IEEE, K. Gopakumar, Fellow, IEEE, L. Umanand, and Carlo Cecati, Fellow, IEEE;**IEEE Transactions on Industrial Electronics, vol. 67, no. 1, pp. 126-135, Jan. 2020** - A Twelve Concentric Multilevel Twenty-Four Sided Polygonal Voltage Space Vector Structure for Variable Speed Drives : Krishnaraj R; K Gopakumar; Apurv Kumar Yadav; L. Umanand; Mariusz Malinowski; Wojciech Jarzyna
**IEEE Transaction on Power Electronics,Vol.34, NO.10,Oct 2019,pp.9906-9915** - A hybrid seven-level inverter using low voltage devices and operation with single DC-link: Apurv Kumar Yadav; K. Gopakumar; Krishnaraj R; L.Umanand; Subhashish Bhattacherya; Wojciech jarzyna
**IEEE Transactions onPower electronics-2019,Vol.34,No.10,Oct 2019,pp.9844-9853** - Instantaneous Balancing of Neutral Point Voltages for Stacked DC-link Capacitors of Multilevel Inverter for Dual Inverter fed Induction Motor Drives: Apurv Kumar Yadav; K. Gopakumar; Krishnaraj R; L.Umanand; Kouki Matsuse; Hisao Kubota
**IEEE Transactions on Power electronics-2019,Vol:34,Issue:3, pages 2505-2514** - Multilevel Twenty-Four Sided Polygonal Voltage Space Vector Structure Generation for IM Drive Using Single DC Source: Krishna Raj R; K. Gopakumar; Mathews Boby; Apurv Kumar Yadav; Leopoldo Garcia Franquelo; Sheldon S. Williamson
**IEEE Transactions on Industrial Electronics-2019.Vol.66,issue:2, Pages1023-1031.** - Seventeen-Level Inverter with Low Component Count for Open-End IM Drives, Abhijit K,Sudharshan.K,Arun Rahul,Gopakumar,Umanand.L,Sujit k Biswas, Carlo Cecati;
**IET Transactions on Power Electronics,2017,**Year: 2018, Volume: 11, Issue: 5, Pages: 922 – 929 - Generation of high resolution 12-sided voltage space vector structure using low voltage stacked and cascaded basic inverter cells;Apurv kumar Yadav, Mathews bobby, Sumit Pramanick,Gopakumar, Umanand. L, leopoldo Franquelo;
**IEEE Transactions on Power Electronics,2018, Vol.33,Issue:9,pages 7349-7358****.** - A Very High Resolution Stacked Multilevel Inverter Topology for Adjustable Speed Drives Viju Nair R, K. Gopakumar, Fellow, IEEE, Leopoldo G. Franquelo, Fellow, IEEE;
**IEEE Transactions on Industrial Electronics, Volume: 65, Issue: 3,****Pages: 2049 –****2056,March 2018.** - A New Two-Phase Five-Level Converter for Three-Phase Isolated Grid-Tied Systems With Inherent Capacitor Balancing and Reduced Component Count;B. Satish Naik ; L. Umanand ; K. Gopakumar ; B. Subba Reddy;
**IEEE Journal of Emerging and Selected Topics in Power Electronics;Year: 2018 , Volume: 6 , Issue: 3 ;Page s: 1325 – 1335.** - A Two-Phase Five-Level Converter With Least Number of Power Switches Requiring Only a Single DC Source ;B. Satish Naik ; L. Umanand ; K. Gopakumar ; B. Subba Reddy
**;****IEEE Journal of Emerging and Selected Topics in Power Electronics;Year: 2018 , Volume: 6 , Issue: 4,Page s: 1942 – 1952** - A Low Order Harmonic Elimination Scheme For Induction Motor Drives Using a Multilevel Octadecagonal Space Vector Structure With a Single DC Source;Mathews Boby;K.Gopakumar; Arun Rahul; Umanand; Subhashish. Bhattacharya; frede Blaabjerg;
**IEEE Transactions on Power Electronics, Volume: 33, Issue: 3, Pages: 2430 – 2437 ,March 2018**. - A 24 sided volatge space vector based IM drive with low order harmonic elimination for the full speed range;Krishna Raj; K.Gopakumar ;Mathews Boby;Mariusz malinowski; Marek jasenki,
**IEEE Transactions on industrial Electronics,****Volume: 64, Issue: 11,Pages: 8437 – 8445,2017.** - Novel symmetric six phase induction motor drive using stacked multilevel inverters witha single DC link and neutral point voltage balancing;Viju Nair;Arun rahul.S;Sumit Pramanick K. Gopakumar; Leopoldo Franquelo,
**IEEE Transactions on industrial Electronics, Vol.64,no.4,: PP.2663-2670, April.2017.** - Extending the Linear Modulation Range to the Full Base Speed Using a Single DC Link Multilevel Inverter with Capacitor Fed H-Bridges for IM drives;Arun R. S.; Sumit Pramanick; R.S. Kaarthik; K. Gopakumar; Frede Blaabjerg,
**IEEE Transactions on Power Electronics,, Vol.32,no.7, PP.5450-5458,July.2017.** - Low Switch Count Nine Level Inverter Topology for Open End Induction Motor Drives; A. Kshirsagar; R. S. Kaarthik; K. Gopakumar; L. Umanand; K. Rajashekara,
**IEEE Transactions on Industrial Electronics,Vol.64,no.2 PP.1009-1017, Feb.2017.** - Extended Linear Modulation Operation of a Common Mode Voltage Eliminated Cascaded Multilevel Inverter with a Single DC supply; Arun Rahul S; Sumit Pramanick; Mathews Boby; K. Gopakumar; Leopoldo G. Franquelo .
**IEEE Transactions on Industrial Electronics,Vol.32,no.7 PP.5450-5458,Jul.2017.** - A Harmonic Suppression Scheme for Full Speed Range of a Two Level Inverter Fed Induction Motor Drive using Switched Capacitive Filter; Sumit Pramanick; Sudharshan Kaarthik; Najath Abdulazeez; K. Gopakumar; Sheldon Williamson; Kaushik Rajashekara.
**IEEE Transactions on Power Electronics,Vol.32,no.3, PP.2064-2071, march.2017.** - Generation of Higher Number of Voltage Levels by Stacking Inverters of Lower Multilevel Structures with Low Voltage Devices for Drives ; Viju Nair R., Arun Rahul S., Kaarthik S., Kshirsagar A. and Gopakumar K..
**IEEE Transactions on Power Electronics,Vol.32,no.1 PP.52-59,Jan.2017.** - Fifth and Seventh Order Harmonic Elimination with Multilevel Dodecagonal Voltage Space Vector Structure for IM Drive Using a Single DC Source for the Full Speed Range ; Boby M., Pramanick S., Kaarthik S., Rahul S.A., Umanand L. and Gopakumar K..
**IEEE Transactions on Power Electronics,Vol.32,no.1 PP.60-68, Jan.2017** - A Predictive Capacitor Voltage Control of a Hybrid Cascaded Multilevel Inverter With a Single DC link and With Reduced Common Mode Voltage Operation; Arun Rahul S; Sudharshan Kaarthik; K. Gopakumar; Leopoldo G. Franquelo; Jose I. Leon..
**IEEE Transactions on Industrial Electronics,Vol.63,no.8, PP.5285-5292, Aug.2016.** - A 3-Level Dodecagonal Space Vector based Harmonic Suppression Scheme for Open-End Winding IM Drives with Single DC Supply ; Pramanick S., Boby M., Najath Abdul Azeez, Gopakumar K. and Williamson S.
**IEEE Transactions on Industrial Electronics,Vol.63.no.11, PP.7226-7233, Nov.2016.** - Multilevel Dodecagonal Voltage Space Vector Structure Generation for Open-end Winding IM using a Single DC Source ; Boby M.,Pramanick S., Kaarthik S., Rahul S. A., Umanand L. and K. Gopakumar.
**IEEE Transactions on Industrial Electronics,Vol.63,no.5 PP.2757-2765 , May-2016.** - Timing calculations for a general N-level dodecagonal space vector structure using only reference phase voltages; R. Sudharshan Kaarthik, K. Gopakumar, Carlo Cecati and Istvan Nagy..
**IEEE Transactions on Industrial Electronics,Vol-63, no.3,pp.1395-1403,March- 2016.** - Reduced common-mode voltage operation of a new seven-level hybrid multilevel inverter topology with a single DC voltage source ; Arun Rahul Sanjeevan, R. Sudharshan Kaarthik, K. Gopakumar, P.P. Rajeevan, Jose I. Leon, Leopoldo G. Franquelo..
**IET Transactions on Power Electronics,vol.9,No.3,pp.519-528,3.9 2016.** - A Voltage Space Vector Diagram formed by Ninteen Concentric Do decagons for Medium Voltage Induction Motor Drives. Sudharshan Kaarthik ; Gopakumar, K. ; Cecati, C; Istvan nagy.
**IEEE Transactions on Industrial Electronics, Volume-62, no.11,pp.6748-6755, Nov. 2015.** - Low Order Harmonic Suppression for Open-end Winding IM with Dodecagonal Space Vector using a Single DC-link Supply. Pramanick, S. ; Abdul Azeez, N. ; Kaarthik, S. ; Gopakumar, K. ; Cecati, C..
**IEEE Transactions on Industrial Electronics, Volume 62,no.9,pp 5340-5347, Sep. 2015.** - Medium Voltage Drive for Induction Machine with Multilevel Dodecagonal Voltage Space Vectors with Symmetric triangles. Sudharshan Kaarthik; Gopakumar, K; Mathew, J. ; Undeland, T.
**IEEE Transactions on Industrial Electronics, Volume-62, Page-79-87, Issue: 1,2015** - A Seventeen-Level Inverter formed by Cascading Flying Capacitor and Floating Capacitor H-bridges. Roshan Kumar, P. ; Sudharshan Kaarthik ; Gopakumar, K. ; Leon, J.I. ; Franquelo, L.G..
**IEEE Transactions on Power Electronics, Volume: 30, Page(s): 3471-3478, Issue: 7,2015** - A Harmonic Suppression Scheme for Open-End Winding Split-Phase IM Drive Using Capacitive Filters, For The Full Speed Range; Najath Abdul Azeez,K Gopakumar,and Carlo Cecati
**IEEE Transactions on IE, Vol-61,issue 10,pp 5213-5221, -2014** - Hysteresis current controller for a general n-level inverter fed drive with online current error boundary computation and nearly constant switching frequency; Anubrata Dey,Najath Abdul Azeez, K.Mathew, K Gopakumar, Marian P Kazmierkowski
**IET Power Electron.,Vol.6,No.8 pp. 1640-1649,Sept.2013** - A Three-level Common-mode Voltage Eliminated Inverter With Single DC-Supply Using Flying Capacitor Inverter and Cascaded H-Bridge ; Roshan Kumar, K.Mathew, K Gopakumar, Jose leon and Leopoldo Franquelo
**IEEE Trans On PELs,Vol.29,No.3,pp1402-1409,March -2014** - A Medium Voltage Inverter Fed IM Drive using Multilevel 12-sided polygonal Vectors, with Nearly Constant Switching Frequency Current Hysteresis Controller ; Najath Abdul Azeez,Anubrata Dey, K.Mathew, K Gopakumar and Marian Kazmierkowski
**IEEE Trans On IE,Vol.61,no.4,pp 1700-1709,April-2014** - A nearly constant switching frequency Current Error Space Vector Based Hysteresis Controller for an IM drive with 12-sided polygonal voltage space vectors , Najath Abdul Azeez,Anubrata Dey, K.Mathew,Jaison mathew,and K Gopakumar
**EPE Journal, Volume: 23-4, 2013** - A Reduced Device-Count Hybrid Multilevel Inverter Topology with single DC Source andImproved Fault Tolerance “,,Rajeevan P.P,and K Gopakumar
**EPE Journal,Vol.23,no.2,pp-14-23,June-2013** - Nearly Constant Switching Frequency Hysteresis Current controller with fast online computation Of Boundary for a 2-level VSI Fed IM”,,Anubrata Dey ,K Mathew,K Gopakumar,and Marian P Kazmierkowski
**EPE Journal,Vol23,No.3,2013** - Multilevel Dodecagonal Space Vector Generation for Induction Motor Drives by Cascading 3 Level and 2 Level Inverters “,K Mathew, Jaison Mathew, Najath Abdul Azeez, Anubrata Dey, L Umanand,K Gopakumar ,
**IET Power Electronics,vol.5,no.8,2012,pp.1324-1332** - A hybrid multilevel inverter system based on dodecagonal space vectors for medium voltage IM drives “,Jaison Mathew, Member IEEE, Mathew K., Najath Abdul Azeez and Gopakumar K ,
**IEEE Transactions on Power Electronics,vol.28,no.8,2013,pp.3723-3732.** - Medium Voltage Drive for Induction Motors using Multilevel Octadecagonal Voltage Space Vectors “,K Mathew, Jaison Mathew, Najath Abdul Azeez, Anubrata Dey, L Umanand, K Gopakumar ,
**IEEE Transactions on Industry Trans. On Power Electronics,vol.28,n0.7,2013,pp.3570-3583** - A Hybrid Five-level Inverter with Common Mode Voltage Elimination having Single Voltage Source for IM Drive Applications”,Rajeevan P.P,K.Gopakumar,
**IEEE Transactions on Industry Applications,vol.48,n0.6,2012,pp.2037-2047.** - A Nine-Level Inverter Topology for Medium Voltage Induction Motor Drive with Open-end Stator Winding”,Rajeevan P.P,sivakumar,K.Gopakumar,Chintan Patel, Abu-rub haitham
**IEEE Transactions on Industrial Electronics,vol.60,no.9,pp.3627-3636-2013** - A Space Vector based Hysteresis Current Controller for a General n-level Inverter Fed Drive with Nearly Constant Switching Frequency Control”,Anubrata Dey, Rajeevan P.P,Rijil Ramchand, Mathew.K,K.Gopakumar,
**IEEE Transactions on Inductrial Electronics,vol.60,no.5,2013,pp.1989-1998** - A Multilevel inverter scheme with dodecagonalvoltage space vectors based on flying capacitor topology for induction motor drives,Jaison Mathew,Rajeevan P.P,K.Mathew,Najath Abdul Azeez, K.Gopakumar,
**IEEE Transactions on Power Electronics,vol.8,no.1,2013,pp.516-523.** - A five level inverter topology with single DC-power suply by cascading aflying capacitor inverter and an H-bridge, P.Roshan Kumar,Rajeevan P.P,K.Mathew, K.Gopakumar, Jose.I Leon, Leopoldo G Franquelo,
**IEEE Transactions on Power Electronics,Vol.27,No.8,Aug2012,pp.3505-3513** - Fast Direct Torque Control of Open-end Induction Motor Drive using 12-sided Polygonal Voltage Space Vectors,Chintan Patel,Rajeevan P.P,Anubrata Dey K.Gopakumar, and Marian P Kazmierkowski, K. Sivakumar,
**IEEE Transactions on IE,Vol.27,NO.1,Jan,2012,pp.400-410** - Low Inductance Axial Flux BLDC Motor Drive for More Electric Aircraft, K.Gopakumar,Sukumar De, K. Sivakumar,
**IET Power Electronics , Vol.5,Issue.1,2012,pp.124-133.** - Online Computation of Hysteresis Boundary for Constant Switching Frequency Current Error Space Vector Based Hysteresis Controller for VSI fed IM Drives,Rijil Ramchand, K. Gopakumar,Chintan Patel, K. Sivakumar, Anandarup Das and Abu-Rub Haitham
**IEEE Trans on PELs,Vol.23,NO.3,2012,pp.1521-1529.** - An asymmetric cascaded H-Bridge inverters for generating 12-sided polygonal space vector diagrams for Motor drives,Mathew.K,Anandarup Das,Chintan Patel,Rijil Ramchand, Gopakumar.K
**EPE Journal,Vol 21 no 1,2011** - A Seven-level Inverter topology for IM Drive using Two-level Inverters and Floating Capacitor Fed H-Bridges,Rajeevan P.P,K.Sivakumar,Chintan Patel,Rijil Ramchand, Gopakumar.K
**IEEE Trans.on Power electronics,Vol.26,Issue.6,2012,pp.1733-1740.** - Multilevel inverters for low power applications,Sukumar De, Debmalya Banerjee ,K.Sivakumar,Chintan Patel,Rijil Ramchand,Gopakumar.K
**IET, Power electronics,Vol4,Iss.4,pp.384-392,2011** - A rotor flux estimation during zero and active vector periods using current error space vector from a hysteresis controller for a sensorless vector control of IM drve , Chintan Patel,Rijil Ramchand,K.Sivakumar, Anandarup Das,Gopakumar.K
**IEEE Trans. On Industrial Electronics,Vol.58,No.6,June 2011** - Reecent Advances and Industrial Applications of Multilevel converters ,Samir Kouro,Mariusz Malinowski,M.Perez,J I Leon,Gopakumar.K,Joseph Pou,L.G Franquelo,Bin Wu,and Jose Rodriguez
**IEEE Trans. On Industrial Electronics,Vol.57,n0.8,Aug-2010,pp2553-2580** - A hybrid multilevel inverter topology for an open-end winding IM drive using two-level inverters in series with a capaciotr fed H-bridge cell ,K.Sivakumar,Anandarup Das, Rjil Ramchand,Chintan Patel,and K.Gopakumar
**IEEE Trans. On Industrial Electronics,Vol.57,no.11,Nov.2010,pp.3707-3815** - A Volatge space vector structure formed by six concentric dodecagons for IM drives. , Anandarup Das,and K.Gopakumar,
**IEEE Trans. on Power electronics,Vol25,no.6,June 2010,pp1480 – 1487** - Two different schemes for three level voltage space vector generation for induction motor drives with reduced DC link Voltage,K.Sivakumar,Anandarup Das,Rjil Ramchand,Chintan Patel,and K.Gopakumar,
**EPE( European power electronics journal),vol.20,no.1,March2010,pp5-12** - A survey on cascaded multilevel inverters ,Mariusz Malinowski,K.Gopakumar,Jose Rodriguez and Marcelo Perez,
**IEEE Trans. On Industrial Electronics-Vol.1, No.1,Dec.2009** - A fivelevel inverter scheme for a four pole induction motor drive by feeding the identical volatge profile windings from both sides ,K.Sivakumar,Anandarup Das, Rjil Ramchand,Chintan Patel,and K.Gopakumar
**IEEE Trans. On Industrial Electronics,Vol.57,no.8,pp.2776-2784,2010.** - Improved Switching Frequency Variation Control of Hysteresis Controlled VSI Fed IM Drives Using Current Error Space Vector ,Rijil Ramchand,K.Sivakumar,Anandarup Das, Chintan Patel,and K.Gopakumar
**IET Power Electronics,Vol.3,No.2,pp.219-231,March 2010** - A Five level inverter scheme for an open end winding induction machine with less number of switches ,Sheron Figarado,K.Sivakumar,Rijil Ramchand,Anandarup Das, Chintan Patel,and K.Gopakumar
**IET Power Electronics,Vol.3,Iss.4,pp637-647-2010** - A Pulse Width Modulated control of Induction Motor drive using multilevel 12-sided polygonal volatge space vectors ,Anandarup Das,K.Sivakumar,P.Chintan, Rijil Ramchand, and K.Gopakumar
**IEEE Trans. On Industrial Electronics,Vol.56,No.7,July 2009** - A DC-link Capacitor Voltage Balancing with CMV Elimination using only the Switching State Redundancies fora Reduced Switch Count Multi-Level Inverter fed IM Drive, Gopal Mondal, Rijil Ramchand,F.sheron,and K.Gopakumar
**EPE( European power electronics journal),Vol.19,N0.1, March-2009** - A dual seven level inverter supply for an open-end winding induction motor drive, Gopal Mondal,K. Gopakumar,Rijil Ramchand,Emil Levi
**IEEE Trans.on IE.Vol.56,no.5,May-2009,pp.1665-1673.** - A combination of Hexagonal and 12-sided polygonal voltage space vector PWM control for Im drives using cascaded two level inverters, Anandarup das,K. Sivakumar, Rijil Ramchand,Chintan Patel, and K.Gopakumar
**IEEE Trans. on IE,Vol.56,NO.5,May 2009.** - Neutral point balancing of NPC three-level inverter with a front end switched rectifier DC source for the full modulation range, K. Sivakumar,Sukumar De,K.Gopakumar, Gopal Mondal,Keith Corzine,
**IET Proceedings – Electric Power Applications,2008** - Three level inverter scheme with reduced power devise count for an induction motor drive with coomn mode voltage elimination, Sheron Figarado, Tanmoy Bhattacharya, Gopal Mondal, and K. Gopakumar,
**IET Power Electronics -2008, vol.1, no.1, pp. 84-92, U.K.** - An 18-sided polygonal voltage space vector based PWM control for an induction motor drive, Sanjay Lakshminarayanan, K. Gopakumar,
**IET Proceedings – Electric Power Applications, 2008, 2, (1), pp. 56-63, U.K** - Twelve-sided polygonal voltage space vector based multi level inverter for an induction motor drive with common mode voltage elimination, Sanjay Lakshminarayanan, Gopal Mondal, P. N. Tekwani,K.K Mohapatra and K. Gopakumar,
**IEEE trans. ON IE vol.54,no.3, October 2007.pp 2761-2768.**. - A reduced switch count five-level inverter with common-mode voltage elimination for an open-end winding induction motor drive; Gopal Mondal, K. Gopakumar, P.N. Tekwani, E. Levi, –
**IEEE Trans. on IE vol.54,no.4,August 2007.pp 2344-2351**. - Linearization of the multi-level SVPWM signal generation in the over-modulation region extending up to six-step mode using only the sampled amplitudes of reference phase voltages; R.S Kanchan, P.N Tekwani and K.Gopakumar-
**EPE JournalVol.17,no.2,June-2007**. - A five-level inverter topology with common-mode voltage elimination for induction motor drives, P. N. Tekwani, R. S. Kanchan, and K. Gopakumar,
**European Power Electronics (EPE) Journal vol.17,no.1, March 2007.pp 11-23**, Brussels, Belgium. - Five-level inverter scheme for an induction motor drive with simultaneous elimination of common-mode voltage and dc-link capacitor voltage unbalance- P.N Tekwani, R.S Kanchan, K.Gopakumar
**IEE proceedings on EPA ,vol152,No.6,November 2005,pp1539-1555** - Synchronised carrier based SVPWM signal generation scheme for the entire modulation range extending upto six-step mode using the sampled amplitudes of reference phase voltages; R.S. Kanchan, K. Gopakumar, Ralph Kennel, Accepted –
**IET – Electric Power Applications ,2007,I,(3),pp.407-415**. - A dual Five-level Inverter Topology for Induction Motor Drive with DC-link Capacitor Voltage Balancing and Common-mode Voltage Elimination In The Complete Modulation Range, P.N Tekwani, R.S Kanchan,K.Gopakumar, ,
**IEEE �IEEE Trans. on Industrial Electronics Part-I,Vol.54,no.5, OCT 2007.pp.2600-2608.** - A dual Five-level Inverter Topology for Induction Motor Drive with DC-link Capacitor Voltage Balancing and Common-Mode Voltage Elimination In The Complete Modulation Range� Part-II, P. N. Tekwani, R. S. Kanchan, and K. Gopakumar,
**IEEE Trans. on Industrial Electronics. Vol 54 No.5, OCT. 2007.pp2609-2617**, - Novel Current Error Space Phasor Based Hysteresis Controller Using Parabolic Bands for Control of Switching Frequency Variations; P.N. Tekwani, R.S. Kanchan, K. Gopakumar,
**IEEE Trans. on IE, Vol 54 No.5, OCt. 2007.pp2648-2656.** - A novel six phase induction motor drive without harmonic filters and with linear voltage control for the full modulation range – K.K Mohapatra, K.Gopakumar,
**EPE (European power electronics and drives) Journal,vol.16,no.4, December-2006** - Three level inverter scheme with common mode voltage elimination and DC link capacitor voltage balancing for an open-end winding induction motor drive, R.S Kanchan, P.N Tekwani, K.Gopakumar,
**IEEE Trans. On Power Electronics,vol.21,No.6, November 2006** - A sensorless field oriented control if induction motor using ripple currents in space phasor based PWM control- K.K Mohapatra, K.Gopakumar,
**EPE Journal,vol.16,no.3,September-2006**. - A multi-level inverter with 12-sided polygonal voltage space vector locations for an induction motor drive, Sanjay Lakshminarayanan, R. S. Kanchan, P. N. Tekwani, and K. Gopakumar,
**IEE Proceedings – Electric Power Applications,vol.153,no.3, May-2006**, U.K. - Five-Level Inverter Topology for IM Drive With DC-Link Capacitor Voltage Balancing and Common-Mode Voltage Elimination in Entire Modulation Range: A Closed-Loop Control Accepted for the
**Polish Journal Electrical Review – Przeglad Elektrotechniczny**R .82 NR 2/2006.pp 73-83. - Independent field oriented control of two split-phase induction motors from a single six-phase inverter, K.K Mohapatra, R.S Kanchan, M.R Baiju, P.N Tekwani, K.Gopakumar,
**IEEE Transactions on Industrial electronics,Vol.52, no.5,October-2005** - Current Error Space Vector Based Hysteresis PWM Controller for Three-level Voltage Inverter fed Drive- accepted — P.N Tekwani, R.S Kanchan, K.Gopakumar accepted for publication in
**IEE-EPA Journal**– Vol.152. No.5. Sept.2005 - A Multi level inverter system for an induction motor with open-end windings. V.T Somasekhar, M.R Baiju, K.Gopakumar, K.K Mohapatra,
**IEEE Transactions on Industrial electronics**, Vol.52, NO.3, June-2005, pp 824-836. - Three level inverter configuration with common mode elimination for an induction motor drive, R.S Kanchan,P.N Tekwani,M.R Baiju,K.Gopakumar, A.Pittet,
**IEE Proceedings on Electric power applications**, Vol.152, No 2.April 2005, pp. 261-270 - Space vector PWM signal generation for multi-level inverters using only the sampled amplitudes of reference phase voltages, R.S Kanchan, M.R Baiju, K.K Mohapatra, P.P Ouseph, K.Gopakumar,
**IEE Proceedings on Electric power applications**, Vol.152, No.2, April 2005, pp.297-309 - A space phasor based current hysteresis controller using adjacent inverter voltage vector selection with smooth transition to six-step operation for a three phase voltage source inverter, M.R Baiju, K.K Mohapatra, R.S Kanchan, P.N Tekwani, K.Gopakumar,
**EPE Journal**, Vol.15, No.1,2005. - A four level inverter scheme with reduced common mode voltage for an induction motor drive, R.S Kanchan, P.N Tekwani, M.R Baiju, K.Gopakumar,
**EPE (European power electronics and drives) journal**, Vol.15, No.3,2005. - Independent speed control of two six-phase induction motors using a single six-phase inverter, K.K Mohapatra, M.R Baiju, K.Gopakumar,
**EPE Journal**, Vol.13,No.3, August 2004, pp.49-62. - A dual two-level inverter scheme with commonmode voltage elimination for an induction motor drive : M.R.Baiju, K.K Mohapatra, R.S Kanchan, K.Gopakumar,
**IEEE Trans. On Power Electronics.**Vol.19. No.3, May 2004, pp.794-805. - Dual two-level inverter scheme for an open-end winding IM drive with a single DC power supply and improved DC bus utilisation : V.T Somasekhar, K.Gopakumar, M.R Baiju.
**IEE Proceedings on Electric power applications. UK. March 2004** - A harmonic elimination and suppression scheme for an open-end winding induction motor drive, K.K Mohapatra,K.Gopakumar,V.T Somasekhar, L.Umanand
**IEEE Transactions on Industrial electronics.**Vol.50,No.6, Dec.2003, pp.1187-1197 - A high resolution multi-level voltage space phasor generation for an open-end winding induction motor drive. M.R Baiju, K.Gopakumar, V.T Somasekhar, K.K Mohapatra, L.Umanand. CD Rom copy No.18.
**EPE Journal**, Vol.13, no.4. November 2003. - A harmonic elimination scheme for an induction motor with open-end windings fed from two inverters with asymmetrical DC link voltages: K.K Mohapatra, K.Gopakumar, V.T Somasekhar,
**EPE journal.**Vol.12., no.4., November-2003. - A five level inverter voltage space phasor generation for an open-end winding induction motor drive. M.R Baiju, K.K Mohapatra, V.T Somasekhar, K.Gopakumar, L.Umanand,
**IEE Proc.-Electr. Power Applications**, Vol.150, No.5, September 2003, pp531-538 - A space vector based PWM method using only instantaneous amplitudes of reference phase voltages for three level inverters. M.R Baiju, K.Gopakumar, V.T Somasekhar,
**EPE journal.**Vol.13.no.2.May-2003. pp 35-45. - Three-level inverter configuration cascading two two-level inverters. V.T Somasekhar, K.Gopakumar,
**IEE Proceedings.**Electr. Power. Appl., Vol.150,No.3, May 2003. pp 245-254. - A multilevel voltage space phasor generation for an open-end winding induction motor drive using a dual�inverter scheme with asymmetrical DC link voltages: V.T Somasekhar, K.Gopakumar, E.G Shivakumar, A.Pittet,
**EPE journal.**Vol.12, no.3, August-2002, pp 7-15 - A space vector modulation scheme for a dual two level inverter fed open-end winding induction motor drive for the elimination of zero sequence currents, V.T Somasekhar, K.Gopakumar, E.G Shivakumar, S.KSinha
**EPE journal..**Vol.12.no.2.May 2002, pp.26-36. - PWM inverter switching stratqgy for a dud two-levelinverter fed open-end winding induction motor drive with a switched neutral,V.T Somasekhar, K.Gopakumar,A.Pittet and V.T Ranganathan
**IEE Proc. -Electric Power Appln.Vol.149.no.2,March2002,pp.153-160 journal.**Vol.12.no.2.May 2002, pp.26-36. - Space vector PWM control of Dual inverter fed open-end winding induction motor drive. E.G Shivakumar, K.Gopakumar, S.K.Sinha, A.Pittet, V.T Ranganathan,
**EPE journal.**Vol.12. no.1. February 2002, pp.9-18. - A PWM scheme for a 3-level inverter cascading two 2-level inverters, V.T Somasekhar K.Gopakumar, M.R Baiju, K.K Mohapatra, L.Umanand
**Journal of the Indian Institute of Science**, Bangalore, vol.82,No.1, Jan-Feb.2002, pp 23-36. - A multi Axis space Phasor Based Current Hysteresis Controller for PWM Inverters : V.Mistry, Sailesh waikar, K.Gopakumar, V.T Ranganathan, L.Umanand
**EPE journal.**Vol.10. no.1. April-2000, pp.17-25. - A sensorless vector control scheme for induction motors using space phasor based current hysteresis controller. Ebenezer.V, K.Gopakumar, V.T Ranganathan,
**EPE journal.**Vol.9.no.3-4. January 2000, pp.42-46. - Vector Control of Induction Motor with Split Phase Stator Windings. K. Gopakumar, V.T Ranganathan, S.R Bhat.
**EPE (European Power Electronics and Drives)**journal. Vol.7. no.1-2 August-October-1997, pp.61-66 - Split�phase induction motor operation from PWM voltage source inverter. K.Gopakumar, V.T Ranganathan, S.R Bhat,
**IEEE Trans. Industry Applns.**Vol.29. No. 5. September/October 1993. pp 927-933 - Performance of Improved Dual Current Source Inverter for Induction Motor Drive. K.Gopakumar,
**et. al. IETE**, India, Vol.67, April – 1987. - Modified Current Source Inverter fed Induction Motor Drive with Reduced Torque Pulsations. K. Gopakumar, et .al.
**IEE Proceedings, vol.131. pt. B. No. 4**July-1984

### Publications in Conferences

- A 5-Level Inverter Topology Using a Single DC-Link with Reduced Switch Count for Open-End Induction Motor Drives; Mriganka Ghosh Majumder ; Apurv K. Yadav ; K. Gopakumar ; Loganathan Umanand ; Krishna Raj R ; Leopoldo G. Franquelo;
**2019 21st European Conference on Power Electronics and Applications (EPE ’19 ECCE Europe)** - A 30-sided polygonal space vector structure with modular low voltage capacitor fed cascaded H bridge for IM drive Rakesh R. ; Apurv Kumar Yadav ; Krishna Raj R. ; K. Gopakumar ; L. Umanan
**d**;**2019 IEEE 28th International Symposium on Industrial Electronics (ISIE)-Vancouver, Canada** - A 30-sided polygonal space vector structure with modular low voltage capacitor fed cascaded H bridge for IM drive; Rakesh R ; Apurv Kumar Yadav ; Krishna Raj R ; K. Gopakumar ; L Umanand:
**2019 IEEE 28th International Symposium on Industrial Electronics (ISIE)** - A Hybrid Seven Level Inverter Topology Formed by Cascading T-Type and Active Neutral Point Clamped Inverter for Induction Motor Drives : Apurv Kumar Yadav; K. Gopakumar; Krishnaraj R; L.Umanand; Subhashish Bhattacharya; Wojciech jarzyna.
**IEEE IECON, 2018, Washington , USA.** - A Thirteen Level Twenty-Four Sided Polygonal Voltage Space Vector Structure for Drives :krishnaraj R;K. Gopakumar; ; L.Umanand; Mariusz Malinowski; Wojciech jarzyna.
**IEEE IECON 2018, Washington, USA.** - Fast Capacitor Balancing Scheme for Low Voltage Cascaded H-bridges in Multilevel Dodecagonal Space Vector Structure : Mohammad Imthias; Krishna Raj R ; Apurv Kumar Yadav; K. Gopakumar; Carlo Cecati .
**IEEE ISIE 2018, Melbourne, Australia.** - A Stacked 7-Level Common Mode Voltage Eliminated Inverter Scheme with Single DC-link for Open-End Induction Motor Drive: Apurv Kumar Yadav; K. Gopakumar; Krishnaraj R; L. Umanand; Kouki matsuse; Hisao Kubota.
**PCIM Europe, 2018, Nuremberg, Germany.** - Six concentric multilevel 24 sided voltage space vector structure for IM drives; Krishna Raj R, K. Gopakumar, Mathews Boby, Apurv Kumar Yadav,Leopoldo Franquelo, Sheldon Williamson.
**IEEE IECON, 2017, Beijing , China.** -
An Induction Motor Drive Scheme Generating Twenty-Four Sided Voltage Space Vector Structure with Linear Modulation Range Near to Base Speed; Krishna Raj R, K. Gopakumar, Mathews Boby, Mariusz Malinowski, Marek Jasinski,
**European Power Electronics (ECCE), EPE -2017. Warsaw, Poland.** - Multilevel dodecagonal space vector generation using stacked inverter cells for IM drives, Apurv Kumar Yadav; Mathews Boby; Sumit Pramanick; K. Gopakumar; Leopoldo G. Franquelo .
**IEEE 26th International Symposium on Industrial Electronics (ISIE), 2017.Edinburgh, UK** - Stacked Multilevel Inverter fed Six Phase Induction Motor with Reduced DC Link and Lower Voltage Devices; Viju Nair, Arun rahul,Gopakumar.K , sheldon williamson and Leopoldo Franquelo*,
**IEEE-ICIT 2017, Toronto, Canada.** - Elimination of dead time transients ina three-level flying capacitor inverter using a state machine for switching state sequence selection;Abhijit.K,R. Sudharshan kaarthik, Mathews Boby,Gopakumar.K , and L.Umanand*,
**IEEE-PEDES 2016, Trivandrum, India.** - A multilevel nine concentric Octa decagonal space vector structure for induction mtor drives using a single DC source; Mathews Boby,Sumit Pramanick, Arun Rahul.S, Gopakumar.K , and L.Umanand*,
**IEEE-PEDES 2016, Trivandrum, India.** - An improvised algorithm for capacitor voltage balancing of symmetrically cascaded floating capacitor H-bridge inverter;Roshan KumarR, Gopakumar.K*,
**IEEE-IECON 2016, Florence, Italy.** - A novel forty nine level stacked inverter topology using low voltage devices for drives; Viju Nair; Sumit Pramanick; Arun Rahul S; K. Gopakumar and B. Basak and Leopoldo,*,
**IEEE-IECON 2016, Florence, Italy.** - A Multilevel Inverter Fed IM Drive with Dodecagonal Voltage Space Vector Structure using a Single DC Source with Linear Modulation Range Near to Base Speed; Mathews Boby; Sumit Pramanick; Arun Rahul S; K. Gopakumar and L. Umanand R,*,
**IEEE-EPE 2016, Carlshruhe, Germany.** - Reduced switch count seventeen level inverter topology for open-end induction motord rives; Abhijit Kshirsagar,sudharshan Kaarthik,Arun Rahul S; K. Gopakumar and L. Umanand R,Sujit Biswas, Carlo cecati*,
**IEEE-IECON 2016,Florence,Italy.** - A new nine level stacked inverter topology for a symmetric six phase induction motor drive with low voltage devices and usinga single DC link, Viju Nair R, Arun Rahul S, Sumit Pramanick, K.Gopakumar and Leopoldo G. Franquelo,*,
**IEEE-ISIE 2016, California, USA.** - Timing Calculations for Three Level Dodecagonal Space Vector Structure From Reference Phase Voltages R. Sudharshan Kaarthik, Prof. K. Gopakumar,Carlo Cecati, Istvan Nagy ,*,
**IEEE-IECON 2015, Yokohama, Japan.** - Nine Level Inverter for Open End Induction Motor with Eight Switches per Phase Abhijit Kshirsagar, R. Sudharshan Kaarthik, Prof. K. Gopakumar,Prof. L. Umanand, and Prof. Kaushik Rajashekhara,*,
**IEEE-IECON 2015, Yokohama, Japan.** - A Hybrid seven level Inverter topologywith a single DC supply and reduced switch count,Arun Rahul S, Sudharshan Kaarthik, K Gopakumar, Rajeevan P.P, Jose I Leon and Leopoldo Franquelo,Istvan Nagy,*,
**EPE-ECCE 2015, Geneva, Switzerland.** - A Hybrid Multilevel Inverter scheme for Induction Motor Drives and Grid-Tied Applications using a Single DC-link, Sudharshan Kaarthik, Roshan Kumar, K Gopakumar, Jose I Leon and Leopoldo Franquelo,*,
**ICIT 2015, Seville, Spain.** - A 19 Level Dodecagonal Voltage Space Vector Structure for Medium Voltage IM Drive, Sudharshan kaarthik, Gopakumar K, Carlo Cecati and Istvan nagy,*,
**IECON 2014, Dallas, Texas, USA** - An open-end winding IM drive with multilevel 12-sided polygonal vectors with symmetric triangles, Sudharshan Kaarthik, Gopakumar .K, jaison mathew, T. Undeland,*,
**EPE ECCE 2014, Lappeenranta, Finaland** - A 5th and 7th order harmonic suppression scheme using capacitive filtering for 2-level VSI fed IM drive Najath Abdul Azeez , Sumit Pramanick, K. Gopakumar and Carlo Cecati,*,
**International Symposium on Power Electronics, Electrical Drives, Automation and Motion Conference 2014,Naples, Italy** - A Seventeen-level Inverter With a Single DC-link For Motor Drives,Roshan Kumar, Sudharshan Karthik,Rajeevan P.P, K Gopakumar,Jose Leon and Leopoldo Franquelo,*,
**IEEE IECON-2013,WIEN, Austria,** - A 5th and 7th order harmonic suppression scheme for open-end winding asymmetrical six-phase IM drive using a capacitor inverter,Najath Abdul Azeez, Jaison Mathew, K Gopakumar, and Carlo Decati,*,
**IEEE IECON-2013,WIEN, Austria,** - A multilevel inverter topology for the generation of Dodecagonal space vectors for medium voltage induction motor with a modified SVPWM strategy for reduction of THD , Jaison Mathew, K.Mathew,Najath,Rajeevan.P.P and K Gopakumar,*,
**EPE-2013,Lille,France,** - Simple Computation Techniques of Online Boundary to Achieve Constant Switching Frequency in any General n-level VSI fed IM Drive using Hysteresis Current Controller, Anubrata Dey,Najath, K Gopakumar, Marian Kazmierkowski*,
**IEEE-ICIT-2013,Cape Town,Sourh Africa** - Multilevel Octadecagonal Space Vector Generation for Induction Motor Drives by Cascading Asymmetric Three Level Inverters,K Mathew, Jaison Mathew, Najath Abdul Azeez, Anubrata Dey, L Umanand, K Gopakumar*,
**IEEE-IECON-2012,Montreal,Canada** - A Nearly Constant Switching Frequency Current Hysteresis Controller with Generalized Parabolic Boundaries using 12-sided Polygonal Voltage,Najath,Anubrata Dey,K.Mathew,Jaison Mathew and K.Gopakumar,
**IEEE-ICEM-2012,France** - Multilevel Octadecagonal Space Vector Generation for Induction Motor Drives by Cascading Asymmetric Three Level Inverters,K.Mathew, Jaison Mathew,Najath, Anubrata, Gopakumar and L.Umanand
**IEEE-IECON-2012,Raleigh,USA** - Direct torque control acheme of IM drive with 12-sided polygonal volatge space vectors,Chintan Patel, Rijil Ramchand,Rajeevan P.P,K.Sivakumar,Anandarup das,.K,Gopakumar.K, and Marian Kazmierkowski,
**EPE-2011,Birmingham** - Online Computation of Current Error Boundary of a Hysteresis Controller for a General n-level VSI Fed Drive with Nearly Constant Switching Frequency,Anubrata Dev,Rajeevan P.P, Mathew.K,Gopakumar.K
**National Power electronics Conference-NPEC-2011,Kolkata.** - Simple online computation of nearly constant switching frequency hysteresis controller boundary for a 2-level VSI fed drive Anubrata Dev,Rajeevan P.P,Rijil Ramchand, Gopakumar K,Abu-Rub Haitham
**PEIA-2011 ( Power Electronics for Industrial Application and Renewable Energy Conversion) Seminar, Qatar-2011.** - Nearly Constant Switching Frequency Hysteresis Current Controller for General n-level Inverter Fed Induction Motor Drive Anubrata Dev,Rajeevan P.P, Chintan Patel,Mathew.K, Gopakumar K,
**IECOn-2012,Melbourne,Australia.** - A Hybrid seven-level Inverter for IM Drive, Rajeevan P.P,Gopakumar K, Sivakumar K, Chintan Patel,Rijil, Gopakumar
**IEEE-PEDES-2010,New Delhi.** - A Hybrid Nine-level Inverter for IM Drive Rajeevan P.P,Gopakumar K, Sivakumar K, Chintan Patel, Gopakumar K, Abu-Rub Haitham,
**ISIE-2011,Gdansk,Poland.** - A Current Error Space Vector Based Hysteresis Controller with Constant Switching Frequency and Simple Online boundary Computation for VSI fed IM Drive , Rijil Ramchand, Chintan Patel, Anandarup Das, Sivakumar K,Gopakumar K,
**IECON-2010,Phoenix,USA.** - Dodecagonal space vector diagram using cascaded H-brideg inverters,Anandarup das,K.Mathew,Chintan Patel,Rijil Ramchand,and K.Gopakumar,
**ISIE-2010,Bari,Italy.** - A There level voltage space vector generation for open-end winding induction motor using single volatge source driven dual two-level inverter, K. Sivakumar,Anandarup Das,Rijil Ramchand, Chintan Patel, K.Gopakumar,
**TENCON -2009, conf.Singapore.** - A simple five level inverter topology for induction motor drive using conventional two level inverters and flying capacitor technique,K. Sivakumar, Anandarup Das,Rijil Ramchand, Chintan Patel, K.Gopakumar,
**IECON -2009, conf.Porto, Portugal.** - Multilevel dodecagonal space vector generation for open end winding induction motor drive using conventional three level inverters,Anandarup Das, K. Sivakumar,Rijil Ramchand, Chintan Patel, K.Gopakumar,
**EPE -2009, conf.Barcelona, Spain.** - A High Resolution pulse wisdth modulation technique using concentric multilevel Dodecagonal voltage space vector structures,Anandarup Das, K. Sivakumar,Rijil Ramchand, Chintan Patel, K.Gopakumar,
**IEEE,ISIE-2009, conf. in Seoul, South Korea.** - A Hysteresis PWM Controller with constant switching frequency for two level VSI fed drives with operation extending to the six -step mode,Rijil Ramchand, Anandarup Das, K.Sivakumar,Chintan Patel, K.Gopakumar,
**PCIM-Europe-2009, conf in Nurenberg, Germany ,May.-11 to May.-13.** - A Front end switched rectifier DC source for neutral point balancing of a NPC three -level inverter for the full modulation range,K. Sivakumar,Sukumar De, K.Gopakumar, Gopal Mondal, Keith Corzine,
**IEEE,ISIE-2008, conf in Cambridge ,June-30 to July-2.** - A multilevel inverter with hexagonal and 12-sided polygonal space vector structure for induction motor drive, Anandarup Das,K. Sivakumar,Gopal Mondal, K.Gopakumar,
**Accepted IEEE,IECON-2008, conf in Orlando,USA .** - An improved sapce phasor based current hysteresis controller with reduced switching frequency variations using variable parabolic bands,Rijil Ramchand, K.Gopakumar,P.N Tekwani, and M.R Baiju,
**National Power electronics conference,2007, INDIA.** - DC link capacitor balancing of NPC inverter using switched voltage source for the full modulation range ,K.Sivakumar,K.Gopakumar and V.T Somasekhar
**National Power electronics conference,2007, INDIA.** - Three-level inverter fed open-end winding IM drive with common mode volatge elimination and reduced power devise count,Sheron Figarado, K.Gopakumar, Gopal Mondal, K.Sivakumar, N.S Dinesh The 33rd annual conference of the
**IEEE Industrial electronics society( IECON), Nov.5-8, 2007,Taipei, Taiwan,pp1238-1243.** - Multilevel inverter with 18-sided polygonal voltage space vector for an open-end winding induction motor drive – Sanjay Lakshminarayanan,Gopal Mondal and K.Gopakumar
**IEEE, EUROCON-2007,conference,Warsaw,Poland** - A Multilevel inverter structure with cascaded two level and three level inverters for IM drive with CMV elimination and DC link capacitor voltage balancing – Gopal Mondal,K.Gopakumar,P.N Tekwani,and Emil Levi
**IEEE, IAS-2007 conference,New Orleans,USA** - A five level inverter scheme with common mode volatge elimination by cascading conventional two level and three level NPC inverters for an induction motor drive – Gopal Mondal, K.Gopakumar,P.N. Tekwani and E.Levi
**EPE-2007 conference**,Aalborg. - Elimination of common monde voltage and fifth and seventh harmonics in a multilevel inverter fed IM drive using 12-sided polygonal voltage space phasor – Sanjay Lakshminarayanan, Gopal Mondal P.N. Tekwani and K.Gopakumar
**IEEE- PEDES, 2006 conference**, Delhi. - Generation of Parabolic Trajectories for Current Error Space Phasor similar to an SVPWM Controller for Control of Switching Frequency Variation in Current Hysteresis PWM Controlled IM Drives- P.N Tekwani R.S Kanchan, and K.Gopakumar
**IEEE, ICIT-2006 conference**, MUMBAI - Switching frequency variation control in hysteresis PWM controller for IM drives using variable parabolic bands for current error space phasor, P.N Tekwani, R.S Kanchan, Sanjay Lakshminarayanan, Gopakumar –
**IEEE-ISIE conference**, Montreal, 2006. - Linearization of the multi-level SVPWM in the over-modulation region-
**National Power electronics conference**, Dec-22 to 24, 2005, INDIA - A Multilevel Inverter Scheme With Inherent Common-mode Voltage Elimination and DC-link Capacitor Voltage Balancing for Open-end Winding Induction Motor Drive –
**National Power electronics conference**, Dec-22 to 24, 2005, INDIA. - Five level inverter topology for induction motor drive with DC link capacitor voltage balancing and common mode voltage elimination in the complete modulation range. P.N Tekwani, R.S Kanchan, K.Gopakumar, accepted of presenting in
**IEEE-PELINCEC-2005**(Power electronics and intelligent control for energy conservation-Warsaw- Poland) - A space vector based PWM switching scheme for the reduction of common mode voltages for a dual inverter fed open-end winding induction motor drive, S.Srinivas, V.T Somasekhar, K.Gopakumar,
**IEEE, PESC-2005 conference, Brazil**. - A self adaptive space phasor based hysteresis current controller with switching of adjacent inverter voltage vectors for three level voltage source inverter fed induction motor drives, P.N Tekwani, R.S Kanchan, K.Gopakumar, accepted for presenting in the
**IEEE, IEMDC conference, USA, San Antonio-2005** - Three level inverter scheme with common mode voltage elimination and DC link capacitor voltage balancing for an open-end winding induction motor drive, R.S Kanchan, P.N Tekwani, K.Gopakumar, accepted for presenting in the
**IEEE IEMDC conference, USA, San Antonio-2005** - A five level inverter topology with common mode voltage elimination for induction motor drives, P.N Tekwani, R.S Kanchan, K.Gopakumar,
**EPE conference, Sept.11-14 Dresden-2005** - A seven level voltage space phasor generation scheme for an open-end winding induction motor drive with asymmetric DC link voltages, R.S Kanchan, P.N Tekwani, M.R Baiju, K.Gopakumar,
**IPEC, 2005, Niggata, Japan** - A sensorless speed control using stator ripple currents for an induction motor drive with space phasor PWM. K.K Mohapatra, M.R baiju, K.Gopakumar, Balram Murty,
**IEE PEMD-2004 conference Edinburgh., UK.**pp 81-86 - A New five level inverter system for an induction motor with open-end windings. V.T Somasekhar, K.Chandrasekhar, K.Gopakumar.
**IEEE . PEDS-2003, Singapore**. - Space vector PWM technique using only the instantaneous reference phase voltages for a three level inverter cascading two 2-level inverters. M.R Baiju, K.K Mohapatra, R.S Kanchan, K.Gopakumar.
**NPEC-2003, IIT Mumbai** - A five level inverter voltage space vector generation for an open-end winding induction motor drive. M.R Baiju, K.K Mohapatra, K.K Mohapatra, L.Umanand,K.Gopakumar.
**IEEE,APEC-2003,USA** - Space vector based PWM method for dual inverter fed open-end winding induction motor drive using only the instantaneous amplitudes of reference phase voltages. M.R Baiju, K.K Mohapatara, K.Gopakumar
**IEEE PEDS- 2003 conference, Singapore**. - A novel modulation scheme for a six phase induction motor with open-end windings, K.K Mohapatra, K. Gopakumar, V.T Somasekhar,
**IEEE IECON-02**conference in Spain-2002, Nov 4th to Nov 8th. - A multilevel inverter system for an induction motor drive with open-end winding;V.T Somasekhar, M.R baiju, K.K Mohapatra,K.Gopakumar,
**IEEE-pEDS Conf. Singapore-2002 conference**. - Multi axis space phasor based multi level current hysteresis controller for an open-end winding induction motor fed from dual inverters; M.R baiju,K.Gopakumar, L.Umanand, Andre Pittet,
**PCIM-2002 conference**, Nurnberg, Germany, pp. 405-411. - A multi level space phasor based PWM strategy for an open end winding induction motor drive using two inverters with different DC link voltages.V.T Somasekhar, K. Gopakumar Andre Pittet, V.T Ranganathan,
**IEEE, PEDS**conference, Indonesia-2001, pp.169-175. - A novel PWM inverter switching strategy for a dual two-level inverter fed open-end winding nduction motor driv: E.G Shivakumar, K.Gopakumar,S.K Sinha, Andrei Pittet, V.T Ranganathan
**IEEE APEC**conference, USA 2001, pp.169-174 - Space vector PWM control of dual inverter fed open-end winding Induction motor drive: E.G Shivakumar, V.T Somasekhar, K.K Mohapatra, K.Gopakumar
**IEEE PEDS**conference, Indonesia 2001, pp.169-174 - Modelling and simulation of sensorless vector control of hybrid step motor-.Muthukumar, S.K. Sinha, K.Gopakumar, L.Umanand. Proceedings, Twenty-Ninth Annual Symposium,
**Incremental Motion Control Systems & Devices**. Berkley, USA 2000, pp.171-179 - Asymmetric multilevel converter for high resolution voltage phasor generation: A Rufer, M.Veenstra, EPFL, Switzerland and K.Gopakumar CEDT, India,
**EPE conf.**Lausanne, switzerland-2000. - A study on the parallel operation of a front end converter for a high speed electric traction drive: Hong-je Ryoo et.al KERI, changwon, Korea and K.Gopakumar, CEDT, India,
**KIEE**Annual autumn Conference-98,Korea.pp.121-124 - Configurations of high power VSI drives for traction applications using multi level inverters and multi phase induction motors: K.Gopakumar, CEDT, India, Geun-Hie Rim, KERI, Changwon, Korea.
**KIEE**(Korean Institution of Electrical and Electronic Engineers), Fall conference-Nov-97 pp.500-504 - A Multi axis space phasor based crrent hysteresis controller for Induction motor drive.Vinay M Mistry,S.P Waikar K.Gopakumar, L.Umanand V.T Ranganathan,
**IEEE PEDS Conference,Singapore- 1997.**. - Vector control of induction motor with split phase stator winding. K.Gopakumar, V.T Ranganathan, S.R Bhat,
**IEEE IAS Conference- 1994.**. - An efficient PWM technique for split phase induction motor operation using dual voltage source inverters. K.Gopakumar, V.T Ranganathan, S.R Bhat,
**IEEE IAS Conference- 1993.**pp582-587. - Three Phase Voltage Source Inverter for a high Speed PCB Drilling Machine. K. Gopakumar. et.al,
**PCIM – 90 on intelligent Motion. Munich. June 90** - Comparative Study of the Dynamic Performance of Two Control schemes for VSI fed induction motor Drive. K. Gopakumar, et.al.
**IEEE. conf.**Computers, Systems and signal Processing, December 1984 - Torque Analysis of a Six-Phase Induction Motor fed From a Current Source Inverter. Gopakumar,
**et.al. IEEE conf. Computers, Systems**and Signal Processing, December 1984

### Ph.D. Students Completed :

- E.G. Shivakumar : Ph.D. – Jan-2002, Thesis title: Study on space vector PWM control of dual inverter fed induction motor with open-end winding.- Professor- UVCE Dept. of EE,Bangalore
- V.T. Somasekhar : Ph.D. – August-2002, Thesis title: Investigations on multi level inverter schemes for induction motor with open-end windings.-Professor-Dept of EE, NIT Warangal.
- Krushna Keshaba Mohapatra : Ph.D. – Sept.-2003, Thesis title: study on harmonic elimination and suppression techniques for variable speed operation of three phase and split phase open-end winding induction motor.- Professor ,Dept of EE,Shiksha O anusnadhan university, Bhubaneswar.
- M.R Baiju : Ph.D. – May-2004, Thesis title: Investigations on multilevel inverter topologies and modulation schemes for induction motor drives.Professor- formerly with Dept of ECE, College of engineering , Trivandrum- Currently PSC member, Govt. of Kerala.
- R.S Kanchan : Ph.D.- August-2005, Thesis title: Investigations on PWM signal generation and common mode voltage elimination schemes for multi level inverter fed induction motor drives.- Senior Engineer, ABB Sweden.
- P.N. Tekwani : Ph.D.- July-2006, Thesis title: Investigations on space phasor based hysteresis current controllers and common-mode voltage elimination scheme with dc-link capacitor voltage balancing for multi-level inverter fed induction motor drives-.Professor, Dept. of EE, Nirma Institute of Technology, Ahmedabad.
- L.Sanjay:PhD,-June-2007,Thesis title: Generation of 12-sided and 18-sided polygonal volatge space vector fed induction motor drives by cascading conventional two-level inverters- Professor Ramiah Institute of Technology. Dept. of EE, Bangalore
- Gopal Mondal:PhD,-July-2008,Thesis title:Reduced switch count multi-level inverter structure with common mode voltage elimination and DC-link capaciotr balancing for IM drives- Senior Engineer, Siemens R&D, Erlangen, Germany.
- Sheron Figarado:PhD,-May-2009,Thesis title:Multilevel inverter topologies with reduced power circuit complexity for medium voltage high power induction motor drives by cascading conventional two-level and three-level inverters- Asst. Professor- Dept of EE,NIT- Suratkal.
- Anandarup Das:PhD,-Feb.2010,Thesis title:Investigations on Dodecagonal space vector generation for induction motor drives. –Associate. Professor, Dept. of EE, IIT Delhi.
- Sivakumar.K:PhD,-April-2010,Thesis title:Multilevel voltage space vector generation for induction motor drives using conventional two-level inverters and H-bridge cells.- Associate Professor- Dept of EE, IIT Hyderabad.
- Rijil Ramchand:PhD,-July.-2010,Thesis title:Investigations on Boundary selection for switching frequency variation control of current error space phasor based hysteresis controllers for inverter fed IM drives.- Professor, Dept of EE, NIT Calicut.
- Sukumar De:PhD,-Jan.-2011.Rectifier and Inverter system for driving axial flux BLDC motors in more electric aircraft applications. – Director , Power Electronics Div. ,Alsthom, Bangalore.
- Patel Chintanbhai Ramubhai:PhD,-March.-2011.Investigations on Sensorless Vector Control using Current Error Space Phasor and Direct Torque Control of Induction Motor Drive Based on Hexagonal and 12-Sided Polygonal Voltage Space Vectors.- Senior Engineer, Electric drive- Cambridge, UK.
- Rajeevan P.P:PhD,-May.-2012.Investigations on hybrid multilevel power converter topologies and control schemes for AC drives.- Associate Professor, Dept. of Avionics,Indian Space Research Institute (IIST), Trivandrum.
- Anubrata Dey:PhD,-Dec.-2012.Investigations on online boundary variation techniques for nearly constant switching frequency hysteresis PWM controller for multilevel inverter fed IM drives.-Asst. Professor, Dept. of EE, IIT Roorkee.
- K.Mathew:PhD,-Aug..-2013.Induction Motor Drives Based on Multilevel Dodecagonal and Octadecagonal Voltage Space Vectors- Professor, Dept. of ECE, Mar Athanasius college of engineering, Kerala.
- Najath Abdul Azeez:PhD,-Jan.-2014.Studies on Current Hysteresis Controllers And Low Harmonic Suppression Techniques for IM Drives with Dodecagonal Voltage Space Vectors- Dept of EE, Onatrio Institute of technology, Oshawa, Canada.
- Jaison mathew:PhD,-Jan.-2014.Investigation on Dodecagonal Multilevel Voltage Space Vector Structures by Cascading Flying Capacitor and Floating H-bridge Cells for Medium Voltage IM Drives-Associate Professor, Dept of EE, Govt. Engineering College, Trichur, Kerala.
- Roshan Kumar pappu:PhD,-Aug.-2014.Studies on Single DC link Fed MultilevelInverter Topologies Using Flying Capacitor And Floating Capacitor Fed H-Bridges- Senior Engineer, Mahindra Electric Aircraft Div. Munich, Germany.
- Sudharshan kaarthik:PhD,Aug.-2015. Multilevel Dodecagonal Space Vector Structures and Modulation Schemes with Hybrid Topologies for Variable Speed AC drives-Asst Professor, Dept. of Avionics,Indian Space Research Institute (IIST), Trivandrum.
- Arun rahul:PhD,Dec.-2016. Invetigations on hybrid multilevel inverters witha single DC supply for zero and reduced common mode voltage operation and extended linear modulation range operation for induction motor drives-Asst. Professor, Dept. of EE, IIT Palghat, Kerala.
- Sumit kumar Pramanick:PhD,Jan.-2017. Switched capacitive filtering scheme for harmonic suppression in variable speed Ac drives-Asst. Professor, Dept. of EE, IIT Delhi
- Mathews Boby:PhD Aug.2017. Multilevel dodecagonal and octadecagonal voltage space vector structures with a single DC supply using basic inverter cells. Dept of EE, University of Concordia, Montreal , Canada.
- Viju Nair.R: PhD, Jan- 2018. Investigations on Stacked multilevel inverter topologies using flying capacitor and H bridge cells for induction motor drives.-Dept of EE, IIT Tirupathy.
- Apurv Kumar Yadav; PhD, Nov-2018. Investigations on Multilevel Voltage Space Vectors Generated by Stacked and Cascaded Basic Inverter Cells with Capacitor Voltage Control for Induction Motor Drives.- Dept. of EE, IIT Roorkee.
- Krishna Raj R.: PhD, Jan-2019. Studies on Multilevel Twenty Four Sided Polygonal Voltage Space Vector Structures Generation With a Single DC Link for Variable Speed Drive Applications.- Asst. Professor ,Centre for automotive research and tribology,IIT Delhi
- Rakesh.R; PhD,Jan 2021: Investigations on generation of 30 sided polygonal voltage space vector structure using a single DC link for induction motor drives.-Dept of Electrical and Computer Eng. Uni. of Maryland, USA
- Mriganka Ghosh Majumder: PhD March 2021;Investigations on Five Level Inverter Schemes for Extending the Linear Modulation Range for Induction Motor Drives:Dept. of EE, University of Houston, Texas, USA.

### Present PhD Students :

- Mohammed Imthiaz (Ph.D.)
- Rahul Dewani (Ph.D.)
- Sourodeep Pal (Ph.D.)
- Tutan Debnath (PhD)
- Prasant Surana(PhD)
- Vivek R S (PhD)