Julio Viola
Researcher/Professor, Prometeo Project – SENESCYT
Grupo de Investigación en Energías, Universidad Politécnica Salesiana.
Cuenca, Azuay EC010105, Ecuador.
e-mail: jcviola@ieee.org | tel.: +593 7 286 2213
“Success is the ability to go from failure to failure without losing your enthusiasm.” – Winston Churchill
Info
Skills
Senior researcher in power electronics and energy R+D projects
Wide experience in study, development and construction of different topologies of power electronics converters: two-level inverter/rectifier, cascaded H-bridge multilevel inverter/rectifier, etc. in applications of electric machines control and active power filtering. Deep skills in the designing of DSP-based control boards and sensor boards used to implement intelligent control algorithms in power electronic converters.
Education
Ph.D., Simón Bolívar University, Caracas, Venezuela.
2008
Ph.D. thesis:
Title: Adaptive Control of Power Electronic Systems with Neural Networks and Lyapunov’s Stability Criterion.
Advisor: Prof. José Restrepo (Ph.D.)
Description: The thesis deals with adaptive current control in power electronic systems using multilayer perceptron neural networks. To ensure the stability of the control system weights of neural networks are adapted by a training algorithm obtained from the second Lyapunov method or Lyapunov’s function method. The models of the systems to be controlled are also obtained and the design of control laws is made. The obtained control systems are first validated through simulations and then by experimental setups of three power systems: a single phase controlled rectifier, a single phase active power filter and a three phase induction machine. For each system the structure based on NARMAX model (Non-linear Auto Regressive Moving Average with exogenous inputs) and the structure of adaptive control with reference model are analyzed, resulting in a total of six control systems.
Electronic Engineer, Universidad Tecnológica Nacional, Paraná, Argentina.
2000
Professional Appointments
2014 – | Researcher/Professor, Prometeo Project – SENESCYT / Universidad Politécnica Salesiana, Cuenca, Ecuador. |
2012 – 2013 | Visiting Researcher/Professor, Prometeo Project – SENESCYT / Universidad Politécnica Salesiana, Cuenca, Ecuador. |
2005 – 2014 | Associate Professor, Electronics and Circuits Department, Simón Bolívar University, Caracas, Venezuela. |
2002 – 2005 | Teaching Assistant, Electronics and Circuits Department, Simón Bolívar University, Caracas, Venezuela. |
2000 – 2002 | Field Engineer, Teleservicios NEA S.A., Paraná, Argentina. |
Indexed Publications
J. Viola, J. Restrepo, J. Aller, F. Quizhpi, and M. Fajardo. Design of current control loop for grid connected inverters operating under nonideal grid conditions. In 2016 IEEE 8th Annual Green Technologies Conference (GreenTech 2016), pages 1–6, April 2016.
M. Abril, J. Restrepo, J. Viola, and J. M. Aller. Fractional order pf controller applied to the induction machine current loop. In Power Electronics and Power Quality Applications (PEPQA), 2015 IEEE Workshop on, pages 1–5, June 2015.
J. M. Aller, J. A. Restrepo, J. C. Viola, P. R. Barbecho, J. Rengifo, and F. A. Quizhpi. Comparison of the parameter estimation for the induction machine dynamic model using instantaneous measurements at standstill and during start-up. In Power Electronics and Power Quality Applications (PEPQA), 2015 IEEE Workshop on, pages 1–6, June 2015.
M. Fajardo, J. Viola, J. Restrepo, F. Quizhpi, and J. Aller. Two-phase active power filter direct current control with capacitor voltages estimation and balance. In Power Electronics and Power Quality Applications (PEPQA), 2015 IEEE Workshop on, pages 1–6, June 2015. J. Viola, J. Restrepo, and J. Aller. Current controller for induction motor using an artificial neural network trained with a lyapunov based algorithm. In 2015 IEEE 24th International Symposium on Industrial Electronics (ISIE), pages 468–475, June 2015.
J. Viola, J. Restrepo, F. Quizhpi, , and J.M. Aller. Predictive control of a three-phase power converter coupled with LCL filter. In International Conference on Industrial Technology (ICIT), 2015 IEEE, pages 1–5, March 2015.
A. Matute, J. Viola, J. Restrepo, J. Aller, and F. Quizhpi. Switched reluctance machine fuzzy modeling applied on a mrac scheme. In 2015 IEEE 6th Latin American Symposium on Circuits and Systems (LASCAS), pages 1–4, February 2015.
J. Viola, J. Restrepo, F. Quizhpi, M.I. Gimenez, J.M. Aller, V. Guzman, and A. Bueno. A flexible hardware platform for applications in power electronics research and education. In Electrical Power Energy Conference (EPEC), 2014 IEEE, pages 1–6, November 2014.
J. Restrepo, J. Viola, and F. Quizhpi. Simplified FPGA implementation of the generalized space vector pulse width modulation (GSVPWM) for three wire three phase inverters. In 2014 IEEE Australasian Universities Power Engineering Conference (AUPEC)., pages 1–6, Perth, September 2014. J. Restrepo, J. Viola, F. Quizhpi, and A. Ginart. Fast detection of sequence components using savitzky-golay filters. In IECON 2014 – 40th Annual Conference of the IEEE Industrial Electronics Society, pages 1–5, November 2014.
H. Bueno, M. Fajardo, F. Quizhpi, J. Viola, and J. Restrepo. Shunt active power filter for harmonic compensation of two-phase nonlinear loads. In 2014 IEEE PES Transmission & Distribution Conference and Exposition (T&D), pages 1–6, Medellin, September 2014.
J. Viola, E. Baethge, A. Berzoy, J. Restrepo, and F. Quizhpi. DC voltage estimation methods for multilevel converter operating with reduced number of sensors. In 2014 IEEE 5th Latin American Symposium on Circuits and Systems (LASCAS), pages 1–4, February 2014.
J. Viola, F. Quizhpi, J. Restrepo, J.P. Pesantez, and M.M. Sanchez. Analysis of a four-phase induction machine with direct torque control. In 2013 15th European Conference on Power Electronics and Applications (EPE), pages 1–9, September 2013.
J.M. Aller, D. Delgado, A. Bueno, J.C. Viola, and J.A. Restrepo. Model of the induction machine including saturation. In 2013 15th European Conference on Power Electronics and Applications (EPE), pages 1–8, September 2013.
Julio Viola, Flavio Quizhpi, and Gustavo Parra. Vector analysis of a four-phase induction machine. In 2013 IEEE Fourth Latin American Symposium on Circuits and Systems (LASCAS), pages 1–4, 2013.
J. C. Viola and F. Quizhpi. Desarrollo de un convertidor electronico multinivel para aplicaciones de compensacion de potencia reactiva. Revista Tecnica Energia – CENACE, 9:96 – 103, 2013.
A. Berzoy, J.C. Viola, and J. Restrepo. Voltage space vector’s computation for current control in three phase converters. Revista Facultad de Ingenieria, 0(64):45–56, March 2012.
A. Berzoy, E. Baethge, J. Restrepo, and J. Viola. Fuzzy control system for maximum power point tracking in solar panels based on DC-DC converter PI current control. In Andean Region International Conference (ANDESCON), 2012 VI, pages 119–122, 2012.
J. Rengifo, J.M. Aller, A. Bueno, J. Viola, and J. Restrepo. Parameter estimation method for induction machines using the instantaneous impedance during a dynamic start-up. In Andean Region International Conference (ANDESCON), 2012 VI, pages 11–14, 2012.
A. Millan, C. Villanueva, J. Restrepo, J. Aller, V. Guzman, M. Gimenez, and J. Viola. Comparing parameter identification strategies for a saturated model of an induction motor. In Andean Region International Conference (ANDESCON), 2012 VI, pages 123–126, 2012.
J.A. Restrepo, J.M. Aller, A. Bueno, J.C. Viola, A. Berzoy, R.G. Harley, and T.G. Habetler. Direct power control of a dual converter operating as a synchronous rectifier. IEEE Transactions on Power Electronics, 26(5):1410–1417, 2011.
J. Restrepo, J.M. Aller, J.C. Viola, A. Bueno, V.M. Guzman, and M.I. Gimenez. Switching strategies for DTC on asymmetric converters driving induction motors. EPE Journal, 21(1):35–42, 2011.
J. Restrepo, J.M. Aller, A. Bueno, J.C. Viola, A. Berzoy, and T.G. Habetler. Direct power control of a dual converter operating as synchronous rectifier. In 2010 Twenty Fifth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), pages 343–348, 2010.
J.A. Restrepo, J.M. Aller, J.C. Viola, A. Bueno, and T.G. Habetler. Optimum space vector computation technique for direct power control. IEEE Transactions on Power Electronics, 24(6):1637–1645, 2009.
J. Restrepo, J.M. Aller, V.M. Guzman, M.I. Gimenez, and J.C. Viola. Switching strategies for DTC on asymmetric converters. In 13th European Conference on Power Electronics and Applications, 2009. EPE ’09, pages 1–9, 2009.
Marcel Ortega, Jose A. Restrepo, J.C. Viola, M.I. Gimenez, and V.M. Guzman. Direct torque control of induction machines with current limitation and ripple reduction using fuzzy logic. Revista Tecnica de la Facultad de Ingenieria. Universidad del Zulia, 31(2):190–198, July 2009.
M.I. Gimenez, V.M. Guzman, J. A. Restrepo, J.M. Aller, A. Bueno, J. C. Viola, A. Millan, and A. Cabello. PLATAFORMA: development of an integrated dynamic test system to determine power electronics systems performance. Revista de la Facultad de Ingenieria – UCV, 23(3):91 – 102, 2008.
M.I. Gimenez, V.M. Guzman, J. Restrepo, J.M. Aller, J. Viola, and A. Bueno. PLATAFORMA: a useful tool for high level education, research and development. In 7th International Caribbean Conference on Devices, Circuits and Systems, 2008. ICCDCS 2008, pages 1–6, 2008.
J. Restrepo, J.M. Aller, J. Viola, and A. Bueno. A simplified rectifier voltage vector selection for direct power control. In 7th International Caribbean Conference on Devices, Circuits and Systems, 2008. ICCDCS 2008, pages 1–5, 2008.
J. C. Viola and J. A. Restrepo. Lyapunov-based training algorithm applied to a continually on line-trained ANN used in the current-loop control of a single-phase switched rectifier. International Journal of Adaptive Control and Signal Processing, 22(6):609–625, 2008.
J. Restrepo, M.I. Gimenez, V. Guzman, J.M. Aller, and J. Viola. Aplicacion del conjunto de vectores de recuperacionİal esquema de control directo de par para el motor de induccion usando un convertidor puente asimetrico. In Memorias del Seminario Anual de Automatica, Electronica Industrial e Instrumentacion, SAAEI, page C62, 2008.
J.A. Restrepo, J.C. Viola, J.M. Aller, and A. Bueno. Algorithm evaluation for the optimal selection of the space vector voltage using DPC in power systems. In 2007 European Conference on Power Electronics and Applications, pages 1–9, 2007.
J. Restrepo, J. Viola, R. Harley, and T. Habetler. Induction machine current loop neuro controller employing a lyapunov based training algorithm. In IEEE Power Engineering Society General Meeting, 2007, pages 1–8, 2007.
J. Viola, J. Restrepo, J.M. Aller, M. Diaz, R.G. Harley, and T.G. Habetler. Simplified control structure for current control of single phase rectifiers using COT-ANN-PWM. In International Joint Conference on Neural Networks, 2007. IJCNN 2007, pages 1370–1374, 2007.
M.A. Diaz, J.C. Viola, and R. Esteller. Analysis of instantaneous amplitude and frequency of intracranial EEG signal to characterize epileptic seizure stages. In 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2007. EMBS 2007, pages 1290–1293, 2007.
J.C. Viola, J.A. Restrepo, V.M. Guzman, and M.I. Gimenez. Direct torque control of induction motors using a fuzzy inference system for reduced ripple torque and current limitation. In Power Electronics and Motion Control Conference, 2006. EPE-PEMC 2006. 12th International, pages 1161–1166, 2006.
J. Restrepo, J. Viola, J.M. Aller, and A. Bueno. A simple switch selection state for SVM direct power control. In 2006 IEEE International Symposium on Industrial Electronics, volume 2, pages 1112–1116, 2006.
J. Viola, J. Restrepo, and M. Diaz. Fuzzy-DTC applied to dynamic load emulation. In 2006 IEEE International Symposium on Industrial Electronics, volume 3, pages 2326–2331, 2006.
J. Viola, M. Strefezza, and J. Restrepo. Improved response of an active load emulation system by using a fuzzy inference system. Latin America Transactions, IEEE (Revista IEEE America Latina), 3(4):37–41, 2005.
J.A. Restrepo, J.C. Viola, M. Ortega, V.M. Guzman, and M.I. Gimenez. A fuzzy-PWM direct torque control of induction machines for current limitation and reduced torque ripple. In 2005 European Conference on Power Electronics and Applications, pages P.1–P.8, 2005.
M. Ortega, J. Restrepo, J. Viola, M.I. Gimenez, and V. Guzman. Direct torque control of induction motors using fuzzy logic with current limitation. In 31st Annual Conference of IEEE Industrial Electronics Society, 2005. IECON 2005, pages 1383–1388, 2005.
Research and Development Projects
2015 | Bidirectional multilevel converter development for solar energy applications (Desarrollo de convertidores multinivel bidireccionales para aplicaciones de energía solar), Fondos concursables – Universidad Politécnica Salesiana, Ecuador. |
2014 | Control Algorithms for active power filters (Algoritmos de ajuste aplicados a los sistemas de filtros activos), Fondos concursables – Universidad Politécnica Salesiana, Ecuador. |
2012 | Control of Power Electronics Systems for Improvements in the Energy Efficiency (Control de sistemas de Electrónica de Potencia para mejoras en la eficiencia energética), Prometeo Project – SENESCYT, Ecuador. |
2011 | Development of Power Electronics Converters for the Improvement of Energetic Efficiency and the Incorporation of Alternative Energy Sources, #2011000970 (Desarrollo de convertidores electrónicos de Potencia para el mejoramiento de la eficiencia energética y la incorporación de fuentes alternativas de energía), FONACIT, Venezuela. |
2010 | Platform development for electric machines vector control, static compensators and active filters (Desarrollo de Plataforma para control vectorial de máquinas eléctricas, compensadores estáticos y filtros activos), Universidad Simón Bolívar, Venezuela. |
2009 | Platform project for the development of electric machines vector controllers, active filters and static compensators (Proyecto Plataforma para el desarrollo de Controladores Vectoriales de Máquinas Eléctricas, Filtros Activos y Compensadores Estáticos), Universidad Simón Bolívar, Venezuela. |
2009 | SIEP group Platform IV interface design and implementation (Diseño e Implementación de la Interfaz para la Plataforma IV del Grupo SIEP), Universidad Simón Bolívar, Venezuela. |
2008 | Dual converter for power electronics applications (Proyecto Convertidor Dual para aplicaciones de Electrónica de Potencia), Universidad Simón Bolívar, Venezuela. |
2006 | Development of power electronics intelligent control algorithms by using FPGA (Desarrollo de Algoritmos de Control Inteligente en Electrónica de Potencia Mediante el Uso de FPGA), Universidad Simón Bolívar, Venezuela. |
2006 | System for direct active power control in industrial systems (Sistema para el control directo de potencia activa en sistemas industriales), Universidad Simón Bolívar, Venezuela. |
Conference Activity / Participation
2016 | Oral presentation at 2016 IEEE International Conference on Industrial Technology, ICIT 2015, Design of current control loop for grid connected inverters operating under nonideal grid conditions, Kansas City, United States. | |
2015 | Oral presentation at 2015 24th IEEE International Symposium on Industrial Electronics, ISIE 2015, Current controller for induction motor using an Artificial Neural Network trained with a Lyapunov based algorithm, Buzios, Brazil. | |
2015 | Oral presentation at 2015 IEEE International Conference on Industrial Technology, ICIT 2015, Predictive control of a three-phase power converter coupled with LCL filter, Seville, Spain. | |
2014 | Oral presentation at 5th IEEE Latin American Symposium on Circuits and Systems, LASCAS 2014, DC voltage estimation methods for multilevel converter operating with reduced number of sensors, Santiago, Chile. | |
2013 | Oral presentation at 15th European Conference on Power Electronics and Applications, EPE’13, Analysis of a four-phase induction machine with direct torque control, Lille, France. | |
2012 | Technical Committee Chair of VI Andean Region International Conference, ANDESCON 2012, Cuenca, Ecuador. | |
2009 | Oral presentation at 13th European Conference on Power Electronics and Applications, EPE’09, Switching strategies for DTC on asymmetric converters, Barcelona,Spain. | |
2007 | Organizing Committee Member of VI Latin American Conference on Biomedical Engineering, CLAIB 2007, Isla Margarita, Venezuela. | |
2007 | Poster presentation at 11th European Conference on Power Electronics and Applications, EPE’07, Algorithm evaluation for the optimal selection of the space vector voltage using DPC in power systems, Aalborg, Denmark. | |
2006 | Oral presentation at 6th IEEE International Symposium on Industrial Electronics, ISIE 2006, Fuzzy-DTC applied to dynamic load emulation, Montreal, Canada. | |
2005 | Oral presentation at 31st Annual Conference of IEEE Industrial Electronics Society, IECON 2005, Direct torque control of induction motors using fuzzy logic with current limitation, Raleigh, USA. |
Reviewing Activity
Reviewer of IEEE Transactions on Power Electronics, ISSN: 0885-8993.
Reviewer of International Journal in Renewable Energies, ISSN: 1309-0127.
Reviewer of Revista de Ciencia y Tecnologia INGENIUS, ISSN: 1390-650X.
Reviewer of Revista Infociencia, ISSN: 1390-339X.
Teaching Experience
Undergraduate Courses
- Electronic Circuits Introduction (EC1167).
- Electronic Circuits Analysis (EC1168).
- Electronic Circuits I (EC1177).
- Electronic Circuits Laboratory I (EC1181).
- Electronic Circuits II (EC2178).
- Electric Measurements Laboratory (EC2286).
- Electronic Circuits Laboratory I (EC3192).
- Electronics of the Adquisition Circuits (EC4179).
Postgraduate Courses
- Power Electronics Laboratory (EC6183).
- Special Topics in Power Electronics (EC6816).
- Power Electronics II (EC7136).
Student Advising
2015 – 2016 | Mr. René Zumba and Mr. Romel Rodas, M.Sc. Thesis title “Diseño de dos algoritmos para detección de la condición de isla en inversores solares domiciliarios”, Universidad Politécnica Salesiana, Ecuador. |
2015 – 2016 | Mr. William Navas, M.Sc. Thesis title “Obtención del modelo dinámico de un motor trifásico de inducción utilizando técnicas de identificación de sistemas con lógica difusa”, Universidad Politécnica Salesiana, Ecuador. |
2015 – 2016 | Mr. Juan Morocho and Mr. Christian Astudillo, Eng. Thesis title “Diseño y simulación de un emulador de red eléctrica para aplicaciones en energía solar”, UniversidadSimón Bolívar, Venezuela. |
2014 | Mr. Felipe Peña, M.Sc. Thesis title “Implementación de un controlador adaptativo para filtros activos de potencia”, Universidad Politécnica Salesiana, Ecuador. |
2014 | Mr. Edgar Criollo, M.Sc. Thesis title “Diseño e implementación de un controlador difuso tolerante a fallas, aplicado al control de nivel de líquido”, Universidad Politécnica Salesiana, Ecuador. |
2011 – 2014 | Mr. Arnaldo Matute, M.Sc. Thesis title “Desarrollo de un generador de modelos difusos para la máquina de reluctancia conmutada”, Universidad Simón Bolívar,V enezuela. |
2013 – 2014 | Mr. Erick Baethge, M.Sc. Thesis title “Métodos de estimación de tensiones de bus en un convertidor multinivel para aplicaciones de control directo de corriente”, Universidad Simón Bolívar, Venezuela. |
2009 – 2010 | Miss Maria Patricia Barrezueta, Eng. Thesis title “La red inteligente: Estudio de estabilidad de una red industrial”, Universidad Simón Bolívar, Venezuela. |
2007 – 2008 | Mr. Arnaldo Matute, Eng. Thesis title “Diseño e implementación de un sistema de frenado regenerativo para una máquina de inducción”, Universidad Simón Bolívar, Venezuela. |
2007 – 2008 | Mr. Carlos Gomez, Eng. Thesis title “Desarrollo e implementación de hardware para la segunda versión del circuito probador de tarjetas DVC”, Universidad Simón Bolívar, Venezuela. |
Languages
Self Assessment European level CEFR (C2 maximum evaluation)
Understanding | Speaking | Writing | ||||
---|---|---|---|---|---|---|
Listening | Reading | Interaction | Production | |||
Spanish | Mother Tong | C2 | C2 | C2 | C2 | C2 |
English | Advanced | C1 | C2 | C1 | C2 | C2 |
Professional Memberships / Affiliations
IEEE Power Electronics Society Member
IEEE Industrial Electronics Society Member
Awards and Honors
2014 | Accredited Member of the Research Prometeo Project (“II” Category), SENESCYT, Ecuador. |
2012 | Accredited Member of the Research Prometeo Project (Senior Category), SENESCYT, Ecuador. |
2011 | Accredited Member of the Research and Innovation Promotion Program (PEII – Level “B”), FONACIT, Venezuela. |
2008 | Ph.D. Thesis with Outstanding Mention, Simón Bolívar University, Venezuela. |
2006 | Accredited Member of the Research Promotion Program (PPI – Level I), FONACIT, Venezuela. |