Optimization of a CSI inverter and DC/DC elevator with silicon carbide devices, for applications in electric traction systems

The applications of electric traction systems currently focus on developing technologies with greater energy efficiency and lower environmental impact. Manufacturers of hybrid and electric vehicles are looking for ways to improve and optimize the efficiency of their models. Manufacturers are looking for more efficient and more compact converter topologies. The use of new band gap materials in the construction of these topologies has generated many debates and new lines of research especially in the optimization of these topologies. The silicon carbide (SiC) based switching devices provide significant performance improvements in many aspects, including lower power dissipation, higher operating temperatures, and faster switching, compared with conventional Si devices, all these features make that these devices generate interest in applications for electric traction systems. This work presents a method for improving total harmonic distortion (THD) in the currents of output and efficiency in SiC current source inverter for future application in an electric traction system. The method proposed consists in improving the coupling of a bidirectional converter topology V-I and CSI. The V-I converter serves as a current regulator for the CSI and allows the recovery of energy. The method involves an effective selection of the switching frequencies and phase angles for the carriers signals present in each converter topology. With this method, it is expected to have a reduction of the total harmonic distortion THD in the output currents. In addition, an analysis of the losses in the motor and topologies of power converters is developed considering the optimization method previously analyzed. The weighted average efficiency of the whole system (power converters + motor) in differents conditions of operations is presented.Las aplicaciones de los sistemas de tracción eléctrica actualmente se centran en el desarrollo de tecnologías con mayor eficiencia energética y menor impacto ambiental. Los fabricantes de vehículos híbridos y eléctricos están buscando formas de mejorar y optimizar la eficiencia de sus modelos. Los fabricantes buscan topologías de convertidores más eficientes y más compactas. El uso de nuevos materiales de banda prohibida en la construcción de estas topologías ha generado muchos debates y nuevas líneas de investigación, especialmente en la optimización energética de las mismas. Los dispositivos de conmutación basados en carburo de silicio (SiC) proporcionan mejoras significativas en la eficiencia en muchos aspectos, incluida una menor disipación de potencia, temperaturas de funcionamiento más altas y una conmutación más rápida, en comparación con los dispositivos de Si convencionales. Todas estas características hacen que estos dispositivos generen interés en las aplicaciones de sistemas tracción eléctrica. Este trabajo presenta un método para mejorar la distorsión armónica total (THD) en las corrientes de salida y eficiencia en el inversor de fuente de corriente SiC para aplicaciones futuras en un sistema de tracción eléctrica. El método propuesto consiste en mejorar el acoplamiento de una topología de convertidor bidireccional V-I y CSI. El convertidor V-I sirve como un regulador de corriente para el CSI y permite la recuperación de energía. El método implica una selección efectiva de las frecuencias de conmutación y los ángulos de fase para las señales portadoras presentes en cada topología del convertidor. Con este método, se espera una reducción de la distorsión armónica total THD en las corrientes de salida. Además, se desarrolla un análisis de las pérdidas en el motor y las topologías de los convertidores de potencia considerando el método de optimización analizado previamente. Se presenta la eficiencia promedio ponderada de todo el sistema (convertidores de potencia + motor) en diferentes condiciones de operaciónPostprint (published version

The Journal of the Friends' Historical Society vol. 56 No. 4

The applications of electric traction systems currently focus on developing technologies with greater energy efficiency and lower environmental impact. Manufacturers of hybrid and electric vehicles are looking for ways to improve and optimize the efficiency of their models. Manufacturers are looking for more efficient and more compact converter topologies. The use of new band gap materials in the construction of these topologies has generated many debates and new lines of research especially in the optimization of these topologies. The silicon carbide (SiC) based switching devices provide significant performance improvements in many aspects, including lower power dissipation, higher operating temperatures, and faster switching, compared with conventional Si devices, all these features make that these devices generate interest in applications for electric traction systems. This work presents a method for improving total harmonic distortion (THD) in the currents of output and efficiency in SiC current source inverter for future application in an electric traction system. The method proposed consists in improving the coupling of a bidirectional converter topology V-I and CSI. The V-I converter serves as a current regulator for the CSI and allows the recovery of energy. The method involves an effective selection of the switching frequencies and phase angles for the carriers signals present in each converter topology. With this method, it is expected to have a reduction of the total harmonic distortion THD in the output currents. In addition, an analysis of the losses in the motor and topologies of power converters is developed considering the optimization method previously analyzed. The weighted average efficiency of the whole system (power converters + motor) in differents conditions of operations is presented.Las aplicaciones de los sistemas de tracción eléctrica actualmente se centran en el desarrollo de tecnologías con mayor eficiencia energética y menor impacto ambiental. Los fabricantes de vehículos híbridos y eléctricos están buscando formas de mejorar y optimizar la eficiencia de sus modelos. Los fabricantes buscan topologías de convertidores más eficientes y más compactas. El uso de nuevos materiales de banda prohibida en la construcción de estas topologías ha generado muchos debates y nuevas líneas de investigación, especialmente en la optimización energética de las mismas. Los dispositivos de conmutación basados en carburo de silicio (SiC) proporcionan mejoras significativas en la eficiencia en muchos aspectos, incluida una menor disipación de potencia, temperaturas de funcionamiento más altas y una conmutación más rápida, en comparación con los dispositivos de Si convencionales. Todas estas características hacen que estos dispositivos generen interés en las aplicaciones de sistemas tracción eléctrica. Este trabajo presenta un método para mejorar la distorsión armónica total (THD) en las corrientes de salida y eficiencia en el inversor de fuente de corriente SiC para aplicaciones futuras en un sistema de tracción eléctrica. El método propuesto consiste en mejorar el acoplamiento de una topología de convertidor bidireccional V-I y CSI. El convertidor V-I sirve como un regulador de corriente para el CSI y permite la recuperación de energía. El método implica una selección efectiva de las frecuencias de conmutación y los ángulos de fase para las señales portadoras presentes en cada topología del convertidor. Con este método, se espera una reducción de la distorsión armónica total THD en las corrientes de salida. Además, se desarrolla un análisis de las pérdidas en el motor y las topologías de los convertidores de potencia considerando el método de optimización analizado previamente. Se presenta la eficiencia promedio ponderada de todo el sistema (convertidores de potencia + motor) en diferentes condiciones de operació

Analysis of power converters with devices of SiC for applications in electric traction systems

This article presents the analysis of two topologies of power converters. Voltage Source Inverter (VSI) and Current Source Inverter (CSI) proposals for traction system applications, these topologies are implemented with silicon carbide devices. The use of SiC semiconductors allow working at high switching frequency (100KHz), increase the working temperature range and decreasing power losses during conduction and activation of the semiconductors. The objective is analyze these topologies and select the one that provides the best performance and behavior at high frequency to improve it on a electric traction system.Postprint (author's final draft

Control method of impedance network in SiC power converters for HEV/EV

Silicon carbide (SiC) devices provide significant performance improvements in many aspects, including lower power dissipation, higher operating temperatures, and faster switching, compared to conventional Si devices. All these features helped increase the interest in the applications of these devices for electric drive systems. The inclusion of an impedance network to elevate DC voltage would improve performance of an electric-traction system, because the topologies of impedances networks can eliminate the need of a DC-DC converter. However, it is important to know control methods that applicable to this type of topologies to systems that are more efficient. This paper presents the analysis of a control method in a power converter topology using SiC devices with an impedance network to elevate DC voltage for electric traction applications. The proposed analisys includes the implementation of a control method in Current Fed Quasi-Z topology, with 100 kHz switching frequency, and its analysis using the simulation of the control method, the power losses in SiC devices and the stress on passive components in the impedance network. Finally, the obtained results are compared with a conventional Current Fed Quasi-Z topology built with silicon devices at a low switching frequency (2 KHz).Postprint (author's final draft

Implementation of high frequency SVM in a digital system for CS-SiC inverter

The operation of current source inverters at high frequency allows to reduce the size of the input coil and output filters. These advantages allowed to obtain converters with better performance and to reduce the size and weight of the passives elements, decreasing the manufacturing costs and while keeping the current harmonic distortion low. For these reasons, it is necessary to implement a modulation technique that allows the converter to work at a higher frequency 100 KHz. This article presents the design and implementation of a Space Vector Modulation (SVM) technique for high switching frequencies for a Current Source Inverter (CSI) topology implemented with SiC devices. The technique is programmed and implemented in a PIC 24FJ256GA406 microcontroller, for the activation and control of SiC devices in each leg of power converter.Postprint (author's final draft

Method to reduce THD and improve efficiency in SiC power converter.

This paper presents a method to reduce total harmonic distortion (THD) and improve efficiency of a topology of power converter using SiC devices. The method consists of two parts: the first part finds the optimum offset angle between two carrier signals that are sent to the first stage of the V-I converter and PWM modulation for the current source inverter (CSI), to reduce the total harmonic distortion in the output currents. The V-I converter transforms the voltage source of the battery into a current source for the inverter. The V-I converter operates at 30 kHz and the CSI at 55 kHz switching. The second part consists of using SiC devices to increase the operating range in frequency, and reduce the power losses in the devices, which will improve the efficiency of the analyzed topology. Besides, a comparative study between the SiC topology and a topology with conventional Si devices was proposed, the results of simulations analyzed the power losses and THD and compared with the purpose of validating the method proposal.Postprint (author's final draft

The Second Life of Hybrid Electric Vehicles Batteries Methodology of Implementation in Ecuador

Hybrid car sales in Ecuador in the last 10 years are very promising. The presence of hybrid electric vehicles (HEV) in the country generates an increase in nickel metal hydride batteries used (NiHm), these batteries do not follow an adequate recycling and disposal process. Several studies show that these batteries have energy levels and that they can be reused in other applications outside of the car as a power supply. This option of using recovered batteries is known as the second life of the battery (SLB). The reuse of batteries generates options to supply power on a large scale and with this reduce the pollution that these batteries can generate, especially in our country that does not have an optimal recycling process. This chapter presents the design of a methodology for the implementation of second life in Ecuador considering the use of NiHm batteries in HEV. For the design of the methodology, two possible scenarios for its implementation are analyzed. Scenario 1 is the use of NiHm batteries to supply energy to laboratories of a University in the city of Cuenca and scenario 2 shows the use of NiHm batteries as an additional energy source at the Airport of Santa Cruz present in the Galapagos Islands

A simple method for reducing THD and improving the efficiency in CSI topology based on SiC power devices

Silicon carbide (SiC)-based switching devices provide significant performance improvements in many aspects, including lower power dissipation, higher operating temperatures, and faster switching; compared with conventional Si devices, all these features contribute to these devices generating interest in applications for electric traction systems. The topology that is frequently used in these systems is the voltage source inverter (VSI), but the use of SiC devices in the current source inverter topology (CSI), which is considered as an emerging topology, generates interest. This paper presents a method for improving total harmonic distortion (THD) in the currents of output and efficiency in SiC current source inverter for future application in an electric traction system. The method that is proposed consists of improving the coupling of a bidirectional converter topology, voltage current (V-I) and CSI. The V-I converter serves as a current regulator for the CSI, and allows for the recovery of energy. The method involves an effective selection of the switching frequencies and phase angles for the carrier signals that are present in each converter topology. With this method, it is expected to have a reduction of the total harmonic distortion, THD in the output currents. In addition, a comparative analysis between converters with all-SiC technology and converters with hybrid technology is realized, to verify the impact of the SiC devices in the power converters efficiency.Postprint (published version

Análisis Financiero para la Implementación de un Bus Eléctrico Urbano en la Ciudad de Cuenca

The present paper carried out a financial analysis that allows establishing the economic feasibility of implementing electric buses for urban service in the city of Cuenca, which circulate through urban routes that connect the main university campuses of the city, which is located at 2 560 meters above sea level and has an urban population of 329 928 inhabitants; for this purpose, five urban routes were established that allow the connection between the universities, proposing routes with lengths of 14 to 34 km, with a duration of 30 minutes to one hour and fifteen minutes, considering the mobilization of 40 000 students. The costs of analysis include income, which implies the value of the ticket and mobile advertising, on the other hand, there are the expenses, such as the acquisition of the unit, maintenance and spare parts, financing and operating expenses; once the values are determined, net present value (NPV) and internal rate of return (IRR) conditions are applied. As a result, lower and negative values are obtained, resulting in an unprofitable project, and this is due to the $0.31 ticket value; as a conclusion and in order for the project to be profitable, a 61 to 83$ 0.31. Como conclusión, y para que el proyecto sea rentable, se considera una elevación del pasaje en un 61 al 83 %

5to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

El V Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2019, realizado del 6 al 8 de febrero de 2019 y organizado por la Universidad Politécnica Salesiana, ofreció a la comunidad académica nacional e internacional una plataforma de comunicación unificada, dirigida a cubrir los problemas teóricos y prácticos de mayor impacto en la sociedad moderna desde la ingeniería. En esta edición, dedicada a los 25 años de vida de la UPS, los ejes temáticos estuvieron relacionados con la aplicación de la ciencia, el desarrollo tecnológico y la innovación en cinco pilares fundamentales de nuestra sociedad: la industria, la movilidad, la sostenibilidad ambiental, la información y las telecomunicaciones. El comité científico estuvo conformado formado por 48 investigadores procedentes de diez países: España, Reino Unido, Italia, Bélgica, México, Venezuela, Colombia, Brasil, Estados Unidos y Ecuador. Fueron recibidas un centenar de contribuciones, de las cuales 39 fueron aprobadas en forma de ponencias y 15 en formato poster. Estas contribuciones fueron presentadas de forma oral ante toda la comunidad académica que se dio cita en el Congreso, quienes desde el aula magna, el auditorio y la sala de usos múltiples de la Universidad Politécnica Salesiana, cumplieron respetuosamente la responsabilidad de representar a toda la sociedad en la revisión, aceptación y validación del conocimiento nuevo que fue presentado en cada exposición por los investigadores. Paralelo a las sesiones técnicas, el Congreso contó con espacios de presentación de posters científicos y cinco workshops en temáticas de vanguardia que cautivaron la atención de nuestros docentes y estudiantes. También en el marco del evento se impartieron un total de ocho conferencias magistrales en temas tan actuales como la gestión del conocimiento en la universidad-ecosistema, los retos y oportunidades de la industria 4.0, los avances de la investigación básica y aplicada en mecatrónica para el estudio de robots de nueva generación, la optimización en ingeniería con técnicas multi-objetivo, el desarrollo de las redes avanzadas en Latinoamérica y los mundos, la contaminación del aire debido al tránsito vehicular, el radón y los riesgos que representa este gas radiactivo para la salud humana, entre otros