No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Scalable and Accurate Modelling of a WBG-based Bidirectional DC/DC Converter for Electric Drivetrains
Abstract
This article presents the scalable and accurate modelling technique of a Wideband Gap-based (WBG) bidirectional DC/DC converter to achieve high efficiency while satisfying a set of design constraints. Using Si and SiC-based switches, the converter is scaled for different power ratings (10kW~50kW). Moreover, to scale the passive components of the DC/DC converter empirical design approach is developed for inductor while the systematic approach is used for capacitor selection. The accuracy (~95% accurate) of the inductor design approach is verified by the Finite Element Method (FEM) COMSOL software and accurate loss model is validated using the MATLAB tool Simulink®. The proposed study reduces 60% of core losses in comparing with a conventional silicon core, reduces 2.5% of output voltage ripples while maximum efficiency is obtained up to 98.5% at 30kW load using CAS120M12BM2 SiC MOSFET module.
... This section explains the electro-thermal models to estimate the thermal stress of the WBG-based MOSFETs, electrolytic capacitor and the heat sink. The universal losses model is utilized in this paper to simulate the switching behavior used to estimate power losses in a single simulation step [14]. The power losses in the power semiconductor modules are coupled with the thermal model, and the junction temperatures of the semiconductor modules are given as a fed back to the power loss model, which provides a high degree of accuracy in the electro-thermal model of the power semiconductor modules. ...
... As the thermal conductivity of the WBG-based power module is twice that of the Si-IGBT, the operating years to failure will be increased for the WBG-based power modules compared to the Si-IGBT power modules. The medium voltage stress Arrhenius equation for lifetime estimation of electrolytic DC link capacitor is shown in equation (14), which is based on voltage and hot spot temperature factor [5]. ...
As Wide Bandgap (WBG)-based semiconductors are being widely used in Electric Vehicles (EVs) drivetrains, it becomes essential to assess the reliability of the WBG-based power electronics converters (PEC). Nevertheless, the ageing response of WBG-based converters in the EVs throughout a complete mission-profile has remained a significant concern for Automotive Original Equipment Manufacturers (OEMs). This paper presents a reliability assessment of a WBG-based Interleaved Bidirectional high-voltage (HV) DC/DC Converter (IBC) for EV-drivetrains. The reliability of IBC is assessed stepwise using a standard mission-profile based on a reliability estimation toolchain that simulates the thermal wear-out of failure-prone components like the semiconductor's module and DC-link electrolytic capacitor. A modified rainflow algorithm is used to count the thermal stress, swings and expansion of the active and passive components on the IBC system. Outcomes of this article depict that the DC-link capacitor and the upper MOSFET of the half-bridge module are the most failure-prone components when the EV is driven using the dynamic WLTC mission-profile. Moreover, experimental results have presented the accuracy of the electro-thermal modelling by operating 30kW IBC prototype at different load conditions.
... In electric drivetrains, a bidirectional DC-DC converter (BDC) is used as a booster between the electric motor (EM) and battery. During the motor mode, the BDC is used to boost the low unregulated battery voltage to a highly regulated DC link voltage level, while in braking, the battery is recharged using the buck mode of BDC and EM runs as a high voltage generator [1]- [3]. Despite their many benefits, a DC-DC converter adds input current ripples, losses, weight and costs. ...
... On the one hand, the conduction losses are only produced during the on-state of a given semiconductor (MOSFET, IGBT, diode, etc.) and result in the product of the voltage drop and the current through the device, as shown in Equation (2). Although this voltage drop depends on different variables, the conducted current and the junction temperature (Tj) are the more commonly considered factors, as shown in Equation (1). On the other hand, switching losses are produced during the turn-on and turnoff transitions of the semiconductors, due to the non-ideal voltage and current transitions, which produce an eventual coexistence of voltage and current. ...
The advent of Wide-Bandgap (WBG) semiconductors, e.g., Silicon Carbide (SiC) and Gallium Nitride (GaN), power electronics E-drive converters are projected to obtain an increase in power density as ~2x
for SiC devices and ~4x for GaN devices, which demand detailed thermal modeling and analysis of power semiconductors and cooling systems. This paper has proposed high-fidelity (HiFi) modeling of
bidirectional DC-DC converter coupled with liquid cooling system providing detailed information with higher accuracy and less complexity to determine performance during conceptual modeling in electric vehicle drivetrain with minimum testing and development effort.
... In recent years, several bidirectional HV DC/DC converter topologies have been studied and designed for the BEV applications such as Synchronous Boost Converter (SBC) [27], Resonant Boost Converter (RBC) [28], Full-Bridge Converter (FC) [27], ZVS-Boost converter (ZBC) [29], Multidevice Interleaved Boost Converter (MDIBC) [30], Multiport converter (MPC) [31], and 3-Phase Interleaved Bidirectional Converter (IBC) [32]. Each topology has its own advantages and drawbacks and should be chosen based on the functionalities, requirements, efficiency, component count, controllability, compactness, cost and reliability [26]. ...
Automotive Original Equipment Manufacturers (OEMs) require varying levels of functionalities and model details at different phases of the electric vehicles (EV) development process, with a trade-off between accuracy and execution time. This article proposes a scalable modelling approach depending on the multi-objective targets between model functionalities, accuracy and execution time. In this article, four different fidelity levels of modelling approaches are described based on the model functionalities, accuracy and execution time. The highest error observed between the low fidelity (LoFi) map-based model and the high fidelity (HiFi) physics-based model is 5.04%; while, the simulation time of the LoFi model is ~104 times faster than corresponding one of the HiFi model. A detailed comparison of all characteristics between multi-fidelity models is demonstrated in this paper. Furthermore, a dSPACE SCALEXIO Hardware-in-the-Loop (HiL) testbench, equipped with a minimal latency of 18μsec, is used for real-time (RT) model implementation of the EV’s HV DC/DC converter. The performance of the entire HiL setup is compared with the Model-in-the-Loop (MiL) setup and the highest RMSE is limited to 0.54 among the HiL and MiL results. Moreover, the accuracy (95.7%) of the passive component loss estimation is verified through the Finite Element Method (FEM) software model. Finally, the experimental results of a full-scale 30-kW SiC DC/DC converter prototype are presented to validate the accuracy and correlation between multi-fidelity models. It has been observed that the efficiency deviation between the hardware prototype and multi-fidelity models is less than 1.25% at full load. Furthermore, the SiC Interleaved Bidirectional Converter (IBC) prototype achieves a high efficiency of 98.4% at rated load condition.
... The published literature on EV inverters has been more related to design/topology analysis than the modeling issues. Furthermore, these publications are usually focused on a single semiconductor technology such as classical silicon [7,8] or novel wide band gap devices as silicon carbide [9,10]. However, for a performance and behavioral comparison, a universal model-where different semiconductor technologies can be interchangeable-is mandatory. ...
With the increasing demand for electric vehicles, the requirements of the market are changing ever faster. Therefore, there is a need to improve the electric car's design time, where simulations could be an appropriate tool for this task. In this paper, the modeling and simulation of an inverter for an electric vehicle are presented. Four different modeling approaches are proposed, depending on the required simulation speed and accuracy in each case. In addition, these models can provide up to 150 different electric modeling and three different thermal modeling variants. Therefore, in total, there were 450 different electrical and thermal variants. These variants are easily selectable and usable and offer different options to calculate the electrical parameters of the inverter. Finally, the speed and accuracy of the different models were compared and the obtained results presented.
A Proportional-Integral-Derivative (PID)-controlled synchronous buck converter (SBC)-based battery charging system was designed to charge a lead-acid cell battery using commercially available Photovoltaic (PV) panel. The proposed system was installed aboard a fishing trawler to power its electrical system replacing the conventional system, which uses a diesel generator and a few kerosene lamps for lighting purposes. A PID algorithm instead of traditional Maximum power point tracker (MPPT) is used in the proposed system since the charging process of the battery requires a maximum current instead of maximum power. The proposed control algorithm is compared with the popular MPPT technique Perturb and Observation (P&O) to validate its dynamic performance at different solar irradiance levels using MATLAB/Simulink®. The simulation and the experimental results have demonstrated that the dynamic response of the proposed algorithm is significantly improved by considering higher charging current, the capability to charge the battery at low irradiance, high stability, and lower cost. Finally, a successful 15-day field trial was conducted at sea using the proposed system, and a maximum charging current output of 6.5 A was achieved by the SBC during noon time; it was sufficient to charge a 12 V, 100 Ah battery, with a state of charge (SoC) of 33%, at a voltage charging rate of +0.3 V/h.
DC/DC Multiport Converters (MPC) are gaining interest in the hybrid electric drivetrains (i.e., vehicles or machines), where multiple sources are combined to enhance their capabilities and performances in terms of efficiency, integrated design and reliability. This hybridization will lead to more complexity and high development/design time. Therefore, a proper design approach is needed to optimize the design of the MPC as well as its performance and to reduce development time. In this research article, a new design methodology based on a Multi-Objective Genetic Algorithm (MOGA) for non-isolated interleaved MPCs is developed to minimize the weight, losses and input current ripples that have a significant impact on the lifetime of the energy sources. The inductor parameters obtained from the optimization framework is verified by the Finite Element Method (FEM) COMSOL software, which shows that inductor weight of optimized design is lower than that of the conventional design. The comparison of input current ripples and losses distribution between optimized and conventional designs are also analyzed in detailed, which validates the perspective of the proposed optimization method, taking into account emerging technologies such as wide bandgap semiconductors (SiC, GaN).
DC–DC converters with voltage boost capability are widely used in a large number of power conversion applications, from fraction-of-volt to tens of thousands of volts at power levels from milliwatts (mW) to megawatts (MW). The literature has reported on various voltage boosting techniques in which fundamental energy storing elements (inductors and capacitors) and/or transformers in conjunction with switch(es) and diode(s) are utilized in the circuit. These techniques include switched capacitor (charge pump), voltage multiplier, switched inductor/voltage lift, magnetic coupling and multi-stage/-level, and each has its own merits and demerits depending on application, in terms of cost, complexity, power density, reliability, and efficiency. To meet the growing demand for such applications, new power converter topologies that use the above voltage boosting techniques, as well as some active and passive components, are continuously being proposed. The permutations and combinations of the various voltage boosting techniques with additional components in a circuit allow for numerous new topologies and configurations, which are often confusing and difficult to follow. Therefore, to present a clear picture on the general law and framework of the development of next generation step-up dc–dc converters, this paper aims to comprehensively review and classify various step-up dc–dc converters based on their characteristics and voltage boosting techniques. In addition, the advantages and disadvantages of these voltage boosting techniques and associated converters are discussed in detail. Finally, broad applications of dc–dc converters are presented and summarized with comparative study of different voltage boosting techniques.
This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs). The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for motor drive system and battery-charging system with a power pulsation reduction circuit. Simulation results in MATLAB/Simulink and experiments on a 30-kW motor drive and 3.3-kW AC/DC charging prototype validate the performance of the proposed technology. In addition, power losses, efficiency comparison and thermal stress for the integrated charger are illustrated. The results of the analyses show the validity of the advanced integrated charger for electric vehicles.
Power electronics interfaces play an increasingly important
role in the future clean vehicle technologies. This paper
proposes a novel integrated power electronics interface (IPEI) for
battery electric vehicles (BEVs) in order to optimize the performance
of the powertrain. The proposed IPEI is responsible for the
power-flow management for each operating mode. In this paper, an
IPEI is proposed and designed to realize the integration of the dc/dc
converter, on-board battery charger, and dc/ac inverter together in
the BEV powertrain with high performance. The proposed concept
can improve the system efficiency and reliability, can reduce
the current and voltage ripples, and can reduce the size of the
passive and active components in the BEV drivetrains compared
to other topologies. In addition, low electromagnetic interference
and low stress in the power switching devices are expected. The
proposed topology and its control strategy are designed and analyzed
by using MATLAB/Simulink. The simulation results related
to this research are presented and discussed. Finally, the proposed
topology is experimentally validated with results obtained fromthe
prototypes that have been built and integrated in our laboratory
based on TMS320F2808 DSP.
The authors describe a novel pulse-width modulator with
feedforward compensation of input voltage disturbances in boost DC-DC
switched mode power converters. The modulator transforms an open-loop
boost converter into a linear DC voltage amplifier. It is suitable for
simple integrated-circuit implementation using the same building blocks
as existing PWM controllers for switched mode power supplies
Control Design , Analysis and Comparative study of Different Control Strategies of a Bidirectional DC / DC Multiport Converter for Electric Vehicles
- E Nazeraj
- O Hegazy
- J Van Mierlo
E. Nazeraj, O. Hegazy, and J. Van Mierlo, "Control Design, Analysis and Comparative study of Different
Control Strategies of a Bidirectional DC / DC Multiport Converter for Electric Vehicles," Evs30, pp. 1-14, 2017.
Temperature dependent Pspice model of silicon carbide power MOSFET
- Y Cui
- M Chinthavali
- L M Tolbert
Y. Cui, M. Chinthavali, and L. M. Tolbert, "Temperature dependent Pspice model of silicon carbide power
MOSFET," in 2012 Twenty-Seventh Annual IEEE Applied Power Electronics Conference and Exposition
(APEC), 2012, pp. 1698-1704.
A General Scheme for Calculating Switching-and Conduction-Losses of Power Semiconductors in Numerical Circuit Simulations of Power Electronic Systems
- J W Kolar
J. W. Kolar, "A General Scheme for Calculating Switching-and Conduction-Losses of Power
Semiconductors in Numerical Circuit Simulations of Power Electronic Systems," in International Power
Electronics Conference (IPEC05), Niigata,Japan, April., 2005, pp. 4-8.
Hegazy fields of interest include power electronics, electrical machines, modelling and optimization techniques, electric and hybrid electric vehicles, Energy management strategies and control systems, battery management systems (BMS), charging infrastructure with V2X strategies
- Prof
Prof. Hegazy fields of interest include power electronics, electrical machines, modelling and
optimization techniques, electric and hybrid electric vehicles, Energy management strategies and
control systems, battery management systems (BMS), charging infrastructure with V2X strategies,
smart local grid and renewable energy.
Authors Sajib Chakraborty received his B.Sc. and M.Sc. (with distinction) degrees in Electrical and
- D Tran
- S Chakraborty
- Y Lan
- J Van Mierlo
- O Hegazy
D. Tran, S. Chakraborty, Y. Lan, J. Van Mierlo, and O. Hegazy, "Optimized Multiport DC/DC Converter
for Vehicle Drivetrains: Topology and Design Optimization," Appl. Sci., 2018.
Authors
Sajib Chakraborty received his B.Sc. and M.Sc. (with distinction) degrees in Electrical and
Electronic Engineering from the Independent University, Bangladesh in 2013 and 2016;
Since 2017, she has been a Lecturer with Mondragon University. Her main research interests include renewable energies, power electronic converters, power transmission and distribution and energy storage systems
- Argiñe Alacano Loiti
Argiñe Alacano Loiti (PhD'17) received the B.Sc. degree in Industrial Electronics engineering, the
M.Sc. degree in Energy and Power Electronics and the Ph.D. degree in Electric Energy from
Mondragon University, Spain, in 2011, 2013 and 2017 respectively.
Since 2017, she has been a Lecturer with Mondragon University. Her main research interests include
renewable energies, power electronic converters, power transmission and distribution and energy
storage systems.