Wilmar Martinez | KU Leuven (original) (raw)

Conference Papers by Wilmar Martinez

Next-Generation semiconductor devices like Silicon Carbide (SiC) or Gallium Nitride (GaN) have be... more Next-Generation semiconductor devices like Silicon Carbide (SiC) or Gallium Nitride (GaN) have been introduced for many applications in power electronics due to their outstanding characteristics of high frequency and low loss operation [1].

Bookmarks Related papers MentionsView impact

A non-isolated high step-up DC-DC converter with coupled inductor is developed for large voltage... more A non-isolated high step-up DC-DC converter with coupled inductor is developed for large voltage gain applications such as electric mobility and renewable energies. This converter combines the concepts of magnetic integration and interleaving phases that are effective for downsizing of power converters. The developed converter offers a good performance of voltage gain vs. converter size, because, compared with the conventional two-phase interleaved boost converter, it only needs the addition of two diodes and one winding. Nevertheless, in order to describe the design method of the developed high step-up converter, the coupled inductor characterization is required. Therefore, the current ripple characterization of the coupled inductor is analyzed and evaluated in this paper. A 100W prototype is constructed and experimental results are provided to verify the characterization analysis.

Bookmarks Related papers MentionsView impact

Nowadays, there is a great interest on new magnetic materials and their outstanding properti... more Nowadays, there is a great interest on new magnetic materials and their outstanding properties of low iron losses. However, when a magnetic material is experimentallycharacterized, it is important to select a suitable sampling frequency specially when the inverter is driven at a high carrier frequency. Nevertheless, iron losses of a magnetic material under inverter excitation are usually underestimated when the inverter is driven at an insufficient sampling frequency. This paper introduces the iron losses of a magnetic material at high carrier frequency excitation using a GANFET inverter. In addition, the experimental evaluation of iron losses at several sampling frequencies is presented. As a result of the measurements, at low sampling frequencies, minor loops of BH curves could not be well constructed, because the inverter waveforms are not measured properly. Finally, experimental tests at 100 kHz and 1 MHz of carrier frequency presented an underestimation of 21.4% and 25.1%, respectively. This measurement error is presented when the inverter is driven at a sampling frequency lower than the suitable one.

Bookmarks Related papers MentionsView impact

The interleaved boost converter with magnetic coupling is a recent DC-DC converter topology that ... more The interleaved boost converter with magnetic coupling is a recent DC-DC converter topology that has drawn attention for its reduced size and good voltage gain. However, for its proper functioning, a real converter has to be controlled to deal with the unavoidable imbalance of the currents. This paper compares two control techniques applied on an interleaved boost converter with magnetic coupling. Therefore, the characteristics of the selected converter, the average current control and predictive control techniques are presented. As a result, it was found that the average current controller has the characteristic of zero steady state error, in contrast, the predictive controller allows an error in the estimated variables which causes the output voltage not to be equal to the reference value. The predictive controller considers and uses the discontinuous mode of operation, but controller has a higher computational cost than the average current controller.

Bookmarks Related papers MentionsView impact

In current automotive applications, novel and robust communication technologies have been used to... more In current automotive applications, novel and robust communication technologies have been used to optimize some features related to security, fuel consumption and user interface. However, the automotive communication protocols present two problems: 1. the connections between devices are very complex and their maintenance is difficult, and 2. most of the commercial devices, specialized to send data between devices, use proprietary software to perform operations inside the vehicle. In this work, a novel embedded platform was designed to measure and control the speed and torque of electric motors of a 200 kW electric vehicle. It is a versatile, modular and open-source design, which exchanges data with each motor using the CAN Bus protocol to control their speed. Also, the implementation and maintenance of the proposed platform becomes simpler. The proposed platform was built and tested with the devices that are used inside the car.

Bookmarks Related papers MentionsView impact

The aim of this work is to present a novel topology of a three-phase LLC converter with integrate... more The aim of this work is to present a novel topology
of a three-phase LLC converter with integrated magnetics. The
converter operation and the comprehensive theoretical analysis
are presented; this analysis follows the first harmonic
approximation (FHA) approach to simplify the system model.
Usually, LLC converter achieves zero voltage switching (ZVS) as
long as it working in the inductive region. Therefore, the turn off
losses are considered as the main source of the switching losses in
the converter. In this paper the design in optimized to minimize
the switching losses. On the other hand, adapting three discrete
transformer cores in this topology will definitely increase the size
and volume of the converter. As a result, a novel magnetic
integration concept is introduced where all magnetic components
of the three-phases are advantageously combined into a single
magnetic core to increase the converter power density. Finally,
the experimental results are presented to verify the optimized
design by showing a reduction in the turn-off losses and the
effectiveness of adapting the proposed integrated transformer, in
which an increment of 56% in the power density of the converter
could be attained.

Bookmarks Related papers MentionsView impact

Recently, Electric Vehicles (EVs) have required high power density and high efficiency systems in... more Recently, Electric Vehicles (EVs) have required high power density and high efficiency systems in order to save energy and costs. Specifically, in the DC-DC converter that feeds the non-propulsive loads in these vehicles, where the output voltage is much lower than the one of the energy storage unit. Therefore, the output current becomes quite high, and the efficiency and power density are reduced due to the high current ratings. Furthermore, magnetic components usually are the biggest contributors to the mass and volume in these converters. This paper proposes a Three-phase LLC resonant converter with one integrated transformer where all the windings of the three independent transformers are installed into only one core. Using this technique, a high reduction in the core size and thereby an increment in the power density and a reduction of the production cost are obtained. In addition, this integrated transformer is intended to be applied in the novel Three-phase LLC resonant converter with Star connection that is expected to offer reduction of the imbalanced output current, which is produced by tolerances between the phase components. Finally, the proposed converter with the novel integrated transformer is discussed and evaluated from the experimental point of view. As a result, a 70% reduction in the mass of the magnetic cores was achieved.

Bookmarks Related papers MentionsView impact

In this paper, a novel magnetic structure suitable for boost converters is proposed. Multi-phase ... more In this paper, a novel magnetic structure suitable for boost converters is proposed. Multi-phase interleaved method using coupled-inductor has gained attention in electric powertrains for electric, hybrid and fuel cell vehicles in order to achieve high power density. In fact, a four-phase boost converter using coupled inductor is used in the drive system of the Honda CLARITY. In particular, magnetic coupling method is used in coupled inductors, Loosely-Coupled Inductors (LCI) and Closed-Coupled Inductors (CCI). This study is focused on these methods, especially using the CCI. This paper presents a design method of a closed-coupled inductors using generic cores for a four-phase interleaved boost converter. In addition a comparison between the proposed topology with other conventional non-coupled methods is carried out. Furthermore, the evaluation of miniaturization is studied. As a result, the proposed method can achieve a huge reduction in the core volume and mass.

Bookmarks Related papers MentionsView impact

Efficiency is one of the most important aspects to consider in the design of electric systems for... more Efficiency is one of the most important aspects to consider in the design of electric systems for mobility applications. In this study, the interface between the storage system and the inverter is considered. This interface is a step-up DC-DC converter aimed to boost the energy storage voltage to the inverter voltage. This paper introduces the analysis, design, and comparison of four topologies of the interleaved boost DC-DC converter evaluating the effect of magnetic coupling in multi-phase and modular circuits. Additionally, a novel idea of a four-phase coupled inductor is presented. These power DC-DC converters are designed in order to find the suitable arrangement with the best efficiency.

Bookmarks Related papers MentionsView impact

Electric Vehicles demand high efficiency power converter in their powertrains in order to use the... more Electric Vehicles demand high efficiency power converter in their powertrains in order to use the energy of the storage unit in a better way. Specifically, the power converters, that interface the storage unit with the motors, are usually composed of high-losses components. Moreover, the topologies used in these systems present conditions of hard switching and reverse recovery phenomena that reduce the total efficiency in the vehicle. This work analyzes the recovery-less boost converter that can achieve Zero-Current Switching, reverse-recovery reduction and softening of the switching transition. Due to the technique of using two saturable inductors. In addition, the use of next-generation magnetic materials for increasing the efficiency and reducing the reverse recovery current is studied. In this paper, the circuit configuration, the operating principle and the reverse-recovery reduction of the recovery-less converter is reviewed. Moreover, the comparison of ferrites and nanocrystalline soft magnetic materials is presented. Finally, the effectiveness of the proposed comparison is validated by experimental tests. As a result, reduction of the peak recovery current and increase of the efficiency are confirmed, achieving a 71% of reduction of the recovery current and 0.25% of efficiency increase at 1kW of output power.

Bookmarks Related papers MentionsView impact

Nowadays, high power density has become essential in networking, telecommunications and computing... more Nowadays, high power density has become essential in networking, telecommunications and computing applications. Additionally, the electronic equipment used in these applications requires a very-low voltage feeding even when its power supply has a much higher voltage rating. Therefore, high step-down converters with high power density performance are required for these applications. Consequently, a novel two-phase interleaved high step-down converter is proposed in order to fulfill the requirements of high power density and high step-down conversion ratio of these applications. The proposed converter addresses the objective by a particular coupled inductor where three windings are only installed in one core. As a result, the proposed converter can achieve higher step-down ratio than the conventional topologies by adding a winding and two switches to the interleaved two phase buck converter, besides the coupled-inductor configuration. In this paper, the novel topology is introduced and analyzed in order to find its conversion ratio operation. Then, the proposed topology is compared to conventional topologies and some improved high step-down converters recently proposed. Finally, the proposed converter is experimentally validated and the results revealed that the proposed converter shows higher step-down conversion ratio than the conventional buck converter with a further increment of 40% in the conversion ratio when the converter is operating at a duty cycle of 30% and ratio of turns of 2.

Bookmarks Related papers MentionsView impact

Power losses and their consequences in the addition of storage cells have the negative effect of ... more Power losses and their consequences in the addition of storage cells have the negative effect of decreasing the power density and the efficiency in Electric Vehicles. For this reason, an efficiency optimization methodology is required to help reduce that problem. Specifically, in the power converters that interface the storage unit with the electric motors and their inverters, an efficiency optimization is essential to reduce the power losses and thereby downsize the cooling components and the storage unit. In this work, the topology under evaluation is the two-phase interleaved boost converter using different magnetic components such as coupled and non-coupled inductors, which are topologies known as effective for high power density applications. This paper presents a methodology that optimizes the efficiency of the chosen topologies through a complete power loss modeling of each component. Next generation components such as Super Junction Mosfets, GaN and SiC diodes and Mosfets are compared to obtain the most efficient and suitable material to be implemented to the topologies, especially to the converter with coupled-inductor. Moreover, a design procedure is proposed to integrate the loss model and the characteristics of the selected components as the base to obtain the objective function, which is later solved using analytical calculations. Finally, the optimization methodology is validated by experimental tests.

Bookmarks Related papers MentionsView impact

—High step-up DC-DC converters are widely used in many industrial appliances and recently introdu... more —High step-up DC-DC converters are widely used in many industrial appliances and recently introduced in renewable energy systems and automotive applications due to their high voltage gain capability. Nevertheless, current high step-up converters often employ additional circuitry with the purpose of increasing the voltage gain. Consequently, the converter will be bulky, heavy and expensive, because the use of these additional passive and active components influences the power density and the cost of the whole application. Therefore, the well-known techniques of interleaving phases and magnetic coupling are applied in a novel high step-up converter with the purpose of helping tackle these problems. Using these techniques, high voltage gain and reduction of circuit elements can be achieved. In this paper, the operating principle of this converter is summarized and the voltage gain is analyzed. Moreover, the analyzed topology is compared with several outstanding high step-up converters recently proposed that use the concept of interleaving phases and magnetic coupling. Finally, the analyzed converter was experimentally tested and the effectiveness in terms of higher voltage gain and number of components than the current topologies is validated.

Bookmarks Related papers MentionsView impact

Flyback switch mode power supplies have been widely used in low-power applications, such as DC/DC... more Flyback switch mode power supplies have been widely used in low-power applications, such as DC/DC converters, solar micro-inverters and LED drivers. However, flyback converters have several problems related to the volume of the output capacitor as well as high output voltage noise; this is produced by the discontinuous output current. Consequently, interleaved operation with parallel connection on the secondary side can reduce the output current ripple compared with the single-phase flyback converter. Nevertheless, besides the output capacitor, the interleaved operation is unsuitable for transformers if it is desired to obtain light weight and compact performance. To address this problem, the interleaved flyback converter with integrated transformer has been proposed for achieving miniaturization of the output capacitor and transformers. There are mainly two types of the proposed flyback converter with integrated transformer: Parallel and Series types. These two types are categorized based on the connection on the primary side. Nevertheless, quantitative comparison of the volume and power loss has not been analyzed yet. Moreover, the design method of the integrated transformer also has not been conducted with clarity. Hence, in this paper, in order to provide a guide for the design of an interleaved flyback converter for achieving high power density, we analyze the quantitative volume and power losses of the integrated transformer and the input capacitor. Finally, this paper shows some experimental results that validate the appropriateness of the design method for the integrated transformer.

Bookmarks Related papers MentionsView impact

In high efficiency and high temperature industrial applications, wide bandgap semiconductor devic... more In high efficiency and high temperature industrial applications, wide bandgap semiconductor devices, such as: Gallium Nitride (GaN) and Silicon Carbide (SiC), are getting great attention due to their outstanding performance. However, a false turn-on phenomenon can be produced by the switching noise because wide bandgap devices have low threshold voltage. Consequently, the efficiency of a switched-mode power supply using these devices can be decreased. This paper analyzes the gate noise performance using experimental tests and circuit simulations focusing on the parasitic parameters of the power devices. Additionally, this analysis was conducted on the base of the theoretical calculation using an equivalent circuit modeling. As a result, it was obtained that Si MOSFETs and GaN HEMT have different false turn-on mechanism.

Bookmarks Related papers MentionsView impact

The techniques of interleaving phases and magnetic coupling in power converters are effective dow... more The techniques of interleaving phases and magnetic coupling in power converters are effective downsizing the capacitive components as well as the inductive components in certain configurations. These techniques help tackle the problem of large mass and volume in autonomous electric vehicles as the use of the transformer-linked method in interleaved converters facilitates the miniaturization of the inductor, the output capacitor and the cooling system. Consequently, the analysis of all the characteristics of each component in the converter should be taken into account. This study presents the analysis of the output capacitor voltage ripple in the three-phase interleaved boost converter with coupled inductor (Transformer-linked). In this paper, the operating principle of the three-phase interleaved boost converter with coupled inductor is presented, then the output voltage ripple analysis is conducted for each mode of the operating principle, and finally the voltage ripple analysis is validated by experimental tests of a 1kW prototype.

Bookmarks Related papers MentionsView impact

Conventional DC-DC step-up converters present problems of low efficiency and low power density be... more Conventional DC-DC step-up converters present problems of low efficiency and low power density because of: 1. High power losses caused by hard-switching and reverse-recovery phenomenon. 2. High conduction losses produced by large peak currents when the converter has to operate at a high duty cycle. 3. Bulky and heavy cooling systems needed to dissipate the semiconductors losses. And, 4. Big and heavy capacitors and inductors required for smoothing and decoupling. Therefore, a novel Zero-Current-Switching two-phase interleaved boost converter with saturable inductors for reverse-recovery reduction is proposed. This converter can reduce the switching losses in the semiconductors due to the effect of the saturable inductors. Moreover, downsizing of the inductors and the output capacitor can be achieved due to the interleaving technique and the use of saturable inductors. In addition, high step-up operation can be achieved due to the presence of tapped-inductors. In this paper, the circuit configuration and the operation principle of the proposed converter and the reverse-recovery reduction behavior are presented. Finally, the effectiveness of the proposed converter is experimentally validated with a 600W prototype where a recovery-reduction of 58% was achieved.

Bookmarks Related papers MentionsView impact

One of the main problems in autonomous electric vehicles is the volume of the electrical systems... more One of the main problems in autonomous electric
vehicles is the volume of the electrical systems, because bulky
components carry additional mass and high cost to the total
system. Consequently, Interleaving phases and magnetic coupling
techniques have been reported as effective methods for increasing
the power density of the DC-DC converters that interface the
storage unit with the electric motor. However, there are several
converter topologies that use these techniques. Therefore, a
volume assessment of these topologies is required in order to have
a complete understanding when an electric power train is
designed. In this paper, a volume modeling methodology is
introduced with the purpose of comparing four different DC-DC
converter topologies: Single-Phase Boost, Two-Phase Interleaved
with non-coupled inductor, Loosely Coupled Inductor (LCI) and
Integrated Winding Coupled Inductor (IWCI). This analysis
considers the volume of magnetic components, power devices
(conventional and next-generation), cooling devices and
capacitors. As a result, interleaving phases and magnetic coupling
techniques were validated as effective to downsize power
converters. In particular, it was found that LCI and IWCI
converters offer lower volume in comparison with other
topologies.

Bookmarks Related papers MentionsView impact

High step-up converters are widely used in sustainable energy systems and recently used in automo... more High step-up converters are widely used in sustainable energy systems and recently used in automotive applications due to their high voltage gain capability. Nevertheless, with the purpose of obtaining a higher voltage gain, in comparison with conventional boost converters, current high step-up converters often employ additional multiplier cells, which may lead to significant cost-up and low power density. Therefore, a novel two-phase interleaved high step-up converter is proposed in order to minimize additional circuit volume used to achieve large voltage gain. The proposed converter addresses the purpose by a particular coupled inductor where three windings are installed in one or two cores. As a result, the proposed converter can achieve higher voltage gain than the conventional topologies by adding a winding and two diodes to the interleaved two phase boost chopper, besides the coupled-inductor configuration. This paper evaluates two arrangements of the coupled-inductor configuration of the proposed high step-up converter: 1. Three windings integrated in only one core and 2. Two independent inductors with a shared winding. The result revealed that the proposed converter shows higher voltage gain than the normal boost converter and the magnetic integration in the coupled-inductor configuration further increases the voltage gain by 20%.

Bookmarks Related papers MentionsView impact

One of the main problems in autonomous electric vehicles is the energy storage, because a high au... more One of the main problems in autonomous electric vehicles is the energy storage, because a high autonomy and high power condition demand large mass, big volume and high cost of the storage unit. Consequently, in order to avoid power losses and to downsize the storage unit and the electric systems, the electric power train in the vehicle must be as efficient as possible. This paper proposes a methodology to optimize the efficiency of a DC-DC converter that interface the storage unit with the motor's drive. In this way, with the purpose of increasing the efficiency, this methodology combines three techniques: 1) The use of low-loss components such as Si CoolMos, GaN and SiC diodes and Mosfets, and Multilayer Ceramic Capacitors, 2) a complete power loss analysis as a function of the switching frequency and a calculation method of core losses based on the approximation of Fourier Series, and 3) the Area Product Analysis of magnetic components. With this methodology, it is possible to achieve high efficiency and high power density, which is suitable for automotive applications. The methodology has been verified with a set of tests on a 1kW prototype. As a result of the proposed methodology, a power efficiency of 99% was experimentally obtained.

Bookmarks Related papers MentionsView impact

With the purpose of designing the electric powertrain of a high performance electric vehicle capa... more With the purpose of designing the electric powertrain of a high performance electric vehicle capable of running a quarter mile in 10 seconds, firstly it is necessary to calculate the required energy, torque, and power in order to size and select the suitable storage components and electric motors. Secondly, an assessment of the powertrain arrangement is needed to choose the best internal configuration of the vehicle and guarantee the highest efficiency possible. Finally, a design of the power conversion stages, specifically the DC-DC converter that interfaces the storage unit with the electric motors, is required as well. This paper shows the energy calculation procedure based on a longitudinal dynamic model of the vehicle and the selection method of the storage components and motors needed for this application, as well as the design of two 100kW interleaved boost converters with coupled inductors. In addition, a novel operation of the interleaved boost converter is proposed in order to increase the efficiency of the converter. As a result, the designed converter achieved a power density of 24,2kW/kg with an efficiency of 98 %, which was validated by experimental tests of a low power prototype.

Bookmarks Related papers MentionsView impact

Interleaved dc–dc converters with integrated magnetic components capable to achieve high power de... more Interleaved dc–dc converters with integrated magnetic components capable to achieve high power density have recently gained attention in automotive applications for eco-friendly transportation. These circuits may contribute to the downsizing of powertrains for electric vehicles (EVs) and hybrid electric vehicles (HEVs) using close-coupled inductors (CCIs) and loosely coupled inductors (LCIs). In this study, a novel core model for size and loss calculation of the interleaved converter with integrated winding coupled inductors (IWCIs) is proposed to assess the size of magnetic components. This assessment was carried out using the parameters of a 1-kW circuit. As a result, interleaved converters with IWCIs proved to be more effective than the converters with LCIs and CCIs for downsizing the magnetic components. In contrast, it was also found that the interleaved converter with LCIs achieved downsizing of the magnetic component at a duty ratio close to 50%. Finally, the effectiveness of the calculation model was validated through experimental tests.

Bookmarks Related papers MentionsView impact

Integrated magnetic components for interleaved converters have been developed in order to fulfill... more Integrated magnetic components for interleaved converters have been developed in order to fulfill the demand for high power density and high efficiency in power conversion systems. The close-coupled inductor and the loosely coupled inductor methods for interleaved converters are well known as attractive techniques to downsize magnetic components or improve the power conversion efficiency. Moreover, the integrated winding coupled inductor has already been proposed. However, the advantages of the interleaved converter with the integrated winding coupled inductor over the other methods have not been fully elucidated. Consequently, this paper analyzes and evaluates the integrated winding coupled inductor, specifically, the characteristics of the inductor ripple current and the magnetic flux in the core. The analysis shows that the integrated winding coupled inductor provides attractive features compared with the other methods. The effectiveness of the integrated winding coupled inductor is discussed from theoretical and experimental points of view.

Bookmarks Related papers MentionsView impact

A loosely coupled inductor for interleaved power converters has attracted interest for downsizing... more A loosely coupled inductor for interleaved power converters has attracted interest for downsizing magnetic components. Although the loosely coupled inductor is usually designed by adjusting the coupling coefficient in order to meet the design specifications, the coupling coefficient is saturated by the fringing fluxes in the central leg and the external leakage fluxes in the case of the EE or EI magnetic core structures. It is a matter of concern that these fluxes are causes of electromagnetic induced noise and reduction in the downsizing performance. To solve this problem, this paper proposes a short-circuited winding for the coupled inductor in order to reduce the external leakage flux in the windings. The effectiveness of the coupled inductor with a short-circuit ring is evaluated with experimental tests.

Bookmarks Related papers MentionsView impact

One of the main problems of Electric Vehicles is the mass and volume of the electric powertrain. ... more One of the main problems of Electric Vehicles is the mass and volume of the electric powertrain. In particular, the power converters, that interface the storage unit with the motors, are composed of bulky and heavy components. These converters suffer from considerable power losses caused by hard-switching and recovery phenomena. Therefore, the efficiency of the converter decreases, and the mass and volume increases because it is necessary to use bulky and heavy cooling systems to dissipate the power losses produced by these phenomena. This study proposes a novel recovery-less boost converter that can achieve zero-current switching and reverse-recovery reduction by using two saturable inductors for the reduction and softening of the switching transition. Consequently, a high-efficiency performance can be achieved. In addition, the proposed two saturable inductors offer advantages of mass and volume reduction of the auxiliary inductors in comparison with other conventional converters for reverse-recovery reduction. Therefore, power density of the proposed converter can be increased. In this paper, the circuit configuration, the operating principle, and the reverse-recovery reduction of the proposed converter are described. Moreover, the design procedure of the proposed saturable inductors is presented. Finally, the effectiveness of the proposed converter is validated through experiments. As a result, a reduction in both the recovery phenomenon and the auxiliary inductor volume is confirmed, with a 72% reduction in the recovery phenomenon and a 63% reduction in the auxiliary inductor volume.

Bookmarks Related papers MentionsView impact

IEEJ Journal of Industry Applications, May 1, 2015

Bookmarks Related papers MentionsView impact

In order to downsize the storage unit of Hybrid Electric Vehicles, a novel high step-up interleav... more In order to downsize the storage unit of Hybrid Electric Vehicles, a novel high step-up interleaved boost converter has been proposed. This converter is suitable for automotive applications due to its expected high voltage gain. However, the actual voltage conversion ratio may be significantly reduced by the parasitic resistance effect of the circuit because the input current tends to be large at a high step-up operation and therefore the voltage drop at the parasitic resistance may not be ignorable. This paper analyzes the effect of the parasitic resistance on the voltage gain and evaluates the result experimentally. Consequently, it is found that parasitic resistance affects the voltage gain largely as the ratio of the number of turns in the integrated magnetic component of the proposed converter increases and particularly when the duty cycle is larger than 0.5.

Bookmarks Related papers MentionsView impact

A novel integrated magnetic structure suitable for a transformer-linked interleaved boost chopper... more A novel integrated magnetic structure suitable for a transformer-linked interleaved boost chopper circuit is proposed in this paper. Coupled inductors with high coupling are known to be effective for downsizing magnetic components. However, it is difficult to obtain the optional leakage inductance with high coupling for coupled inductors with EE or EI cores because of the fringing effect in the air gap. In order to overcome this problem, a novel integrated magnetic structure is first proposed. Then, a design method for the coupled inductor with the proposed magnetic structure is introduced on the basis of the magnetic circuit model. Finally, the effectiveness of the novel magnetic core structure is validated and discussed from an experimental viewpoint.

Bookmarks Related papers MentionsView impact

One of the main problems in autonomous electric vehicles is the volume of the electrical systems,... more One of the main problems in autonomous electric vehicles is the volume of the electrical systems, because
bulky components carry additional mass and high cost to the total system. Consequently, Interleaving phases
and magnetic coupling techniques have been reported as effective methods for increasing the power density
of the DC-DC converters that interface the storage unit with the electric motor. However, there are several
converter topologies that use these techniques. Therefore, a volume assessment of these topologies is
required in order to have a complete understanding when an electric power train is designed. In this paper, a
volume modeling methodology is introduced with the purpose of comparing four different DC-DC converter
topologies: Single-Phase Boost, Two-Phase Interleaved with non-coupled inductor, Loosely Coupled Inductor
(LCI) and Integrated Winding Coupled Inductor (IWCI). This analysis considers the volume of magnetic
components, power devices (conventional and next-generation), cooling devices and capacitors. As a result,
interleaving phases and magnetic coupling techniques were validated as effective to downsize power
converters. In particular, it was found that LCI and IWCI converters offer lower volume in comparison with
other topologies.

Bookmarks Related papers MentionsView impact

Uno de los grandes inconvenientes de la movilidad eléctrica en Colombia es la baja densidad de po... more Uno de los grandes inconvenientes de la movilidad eléctrica en Colombia es la baja densidad de potencia que presentan los vehículos autónomos. Esto se debe a que la mayoría de fabricantes diseñan sus vehículos para países con terrenos estables y de bajo relieve. Por esta razón, esta investigación muestra el diseño de los diferentes subsistemas eléctricos de un vehículo eléctrico de alto desempeño con alta densidad de potencia y cuya primera aplicación es correr un cuarto de milla en 10 segundos, con el fin de demostrar las capacidades de los vehículos eléctricos y posteriormente ser la base de vehículos eléctricos de uso cotidiano. Este diseño abarca el cálculo de la energía necesaria para correr el cuarto de milla en el tiempo objetivo, pasando por el dimensionamiento y selección de los elementos de almacenamiento y los motores eléctricos, así como la evaluación de la disposición de los diferentes elementos dentro del esquema del vehículo y el diseño tanto del cargador como del convertidor de potencia que realiza la interfaz entre la unidad de almacenamiento y los motores. Actividades que fueron realizadas con el objetivo de lograr una alta eficiencia energética en todos los subsistemas internos del vehículo. De esta manera, se logró diseñar un sistema eléctrico con 600Wh de energía almacenada en supercondensadores distribuidos de tal manera que puedan entregar una corriente de hasta 600A a dos convertidores de potencia que cuentan con una eficiencia teórica del 98% y una densidad de potencia de 24.2kW/kg, los cuales alimentan cuatro motores de 50kW, posibilitando que de manera teórica se alcance el cuarto de milla en 9.91 segundos. Finalmente, esta investigación pretende contribuir al avance de la movilidad eléctrica en Colombia, puesto que el diseño propuesto servirá para la operación de vehículos eléctricos de uso doméstico en topografías variables y terrenos inestables, gracias a la densidad de potencia y alta eficiencia que se logrado por este trabajo investigativo., Abstract. One of the main problems in autonomous electric vehicles is the energy storage, because of the use of low capacity batteries with low power delivery. This work shows the electric design of a high performance electric vehicle capable to run a quarter of a mile in 10 seconds. The concept design of the system combines sizing of storage unit and electrical motors, assessing of system arrangement and design of the charger and of the DC-DC converter which interfaces the storage unit with the electrical motors, taking into account a high efficiency goal. The design achieves an electric system with a 600Wh storage unit using ultracapacitors which can deliver 600A. This unit is connected to two DC-DC converters with 24,2Wh/Kg of power density and 98% of efficiency which feed four 50kW PM motors. This research permits important achievements in the Colombian electric mobility due to the proposed design works for domestic vehicles in variable topographies and unstable

Bookmarks Related papers MentionsView impact

IEEE Workshop on Power Electronics and Power Quality Applications-PEPQA Volume Comparison of DC-... more IEEE Workshop on Power Electronics and Power Quality Applications-PEPQA
Volume Comparison of DC-DC Converters for Electric Vehicles
Jun 2015

Bookmarks Related papers MentionsView impact