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Electric Vehicle Inverter Electro-Thermal Models Oriented to Simulation Speed and Accuracy Multi-Objective Targets
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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.
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... This process involves extensive test coverage in the virtual platform, which mandates 8000 h-10000 h of the EV simulation as a set of complete life cycle requirements [11]. A detailed and accurate HiFi simulation model could slow down the whole EV simulation process as the HiFi PE component's simulation requires very small simulation step-size (1 µs or 0.1 µs) to attain highly accurate results [12]- [16]. In contrast, a standard step-size for an entire EV simulation is 0.01s [17]. ...
... To speed up the power electronics component's simulation time, a multi-scale modelling approach is proposed as a proper solution [6], [16], [18]. Scalable modelling has consisted of High-Fidelity (HiFi) modelling, Medium-Fidelity (MFi) modelling, Low-Fidelity (LoFi) modelling, and mapbased modelling, with simulation step-sizes varying from 0.1 µs to 0.01s. ...
... Moreover, the RT-models can be used to verify the reliability of the PE converters for different mission profiles, thus providing a guideline to estimate the PE components ageing factor [23]. Hence, an RT-model analysis can facilitate the creation of an innovative system configuration for a new class of affordable, safe and efficient EV with less scrutiny [6], [16]. ...
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.
... For the torque and speed Energies 2020, 13, 489 3 of 13 control of the electrical machine, a bidirectional DC-AC converter is employed, and the power is controlled for electric machine current regulation. The following research papers explain the operating principle of each subsystems in detail [1][2][3][4]. ...
... Energies 2020, 13, x FOR PEER REVIEW 3 of 13 is controlled for electric machine current regulation. The following research papers explain the operating principle of each subsystems in detail [1][2][3][4]. ...
... A battery electric vehicle (BEV) powertrain typically consists of power subsystems, based on power electronics switches (e.g., insulated gate bipolar transistors (IGBT) and field effect transistors (FET) components). Furthermore, DC-DC and DC-AC bi-directional converters are integrated within the powertrain, which operate at high switching frequencies, in the order of tens of kHz [1][2][3][4]. The commonplace is that operating currents within these power converters contain harmonics. ...
Electric vehicle (EV) powertrains consist of power electronic components as well as electric machines to manage the energy flow between different powertrain subsystems and to deliver the necessary torque and power requirements at the wheels. These power subsystems can generate undesired electrical harmonics on the direct current (DC) bus of the powertrain. This may lead to the on-board battery being subjected to DC current superposed with undesirable high- and low- frequency current oscillations, known as ripples. From real-world measurements, significant current harmonics perturbations within the range of 50 Hz to 4 kHz have been observed on the high voltage DC bus of the EV. In the limited literature, investigations into the impact of these harmonics on the degradation of battery systems have been conducted. In these studies, the battery systems were supplied by superposed current signals i.e., DC superposed by a single frequency alternating current (AC). None of these studies considered applying the entire spectrum of the ripple current measured in the real-world scenario, which is focused on in this research. The preliminary results indicate that there is no difference concerning capacity fade or impedance rise between the cells subjected to just DC current and those subjected additionally to a superposed AC ripple current.
... The propulsion system includes an electric motor, a battery pack, converters located next to both of them, and buck-boost choppers [1,7]. An electric car powertrain is depicted in the figure below ( Figure 1) [8]. The electric motors that are used in EVs include brushed direct current (DC) motors, induction motors, synchronous reluctance motors, and permanent magnet synchronous and brushless DC motors [1]. ...
... Electric car powertrain[8]. ...
Over the years, an increase in the traffic of electric and hybrid electric vehicles and vehicles with hydrogen cells is being observed, while at the same time, self-driving cars are appearing as a modern trend in transportation. As the years pass, their equipment will evolve. So, considering the progress in vehicle equipment over the years, additional technological innovations and applications should be proposed in the near future. Having that in mind, an analytical review of the progress of equipment in electromobility and autonomous driving is performed in this paper. The outcomes of this review comprise hints for additional complementary technological innovations, applications, and operating constraints along with proposals for materials, suggestions and tips for the future. The aforementioned hints and tips aim to help in securing proper operation of each vehicle part and charging equipment in the future, and make driving safer in the future. Finally, this review paper concludes with a discussion and bibliographic references.
... In [1] and [3] authors published reliability study for automotive DC/DC converters using a similar approach. As described in [4], the junction temperature of switching devices can be estimated with varying levels of accuracy using low to high-fidelity models. Difference between results obtained through these models can be as high as 5.04% [1]. ...
... The inverter is also responsible for transforming the energy obtained by the regenerative brake to power the batteries. As a result, the performance of the EV is directly related to the inverter efficiency [35][36][37]. ...
This article proposes an energy-efficiency strategy based on the optimization of driving patterns for an electric vehicle (EV). The EV studied in this paper is a commercial vehicle only driven by a traction motor. The motor drives the front wheels indirectly through the differential drive. The electrical inverter model and the power-train efficiency are established by lookup tables determined by power tests in a dynamometric bank. The optimization problem is focused on maximizing energy-efficiency between the wheel power and battery pack, not only to maintain but also to improve its value by modifying the state of charge (SOC). The solution is found by means of a Particle Swarm Optimization (PSO) algorithm. The optimizer simulation results validate the increasing efficiency with the speed setpoint variations, and also show that the battery SOC is improved. The best results are obtained when the speed variation is between 5% and 6%.
... Traction inverters can be modeled at different levels [3]: ...
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.
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.
A comprehensive reference of the latest developments in MV drive technology in the area of power converter topologies. This new edition reflects the recent technological advancements in the MV drive industry, such as advanced multilevel converters and drive configurations. It includes three new chapters, Control of Synchronous Motor Drives, Transformerless MV Drives, and Matrix Converter Fed Drives. In addition, there are extensively revised chapters on Multilevel Voltage Source Inverters and Voltage Source Inverter-Fed Drives. This book includes a systematic analysis on a variety of high-power multilevel converters, illustrates important concepts with simulations and experiments, introduces various megawatt drives produced by world leading drive manufacturers, and addresses practical problems and their mitigations methods. This new edition: Provides an in-depth discussion and analysis of various control schemes for the MV synchronous motor drives. Examines new technologies developed to eliminate the isolation transformer in the MV drives. Discusses the operating principle and modulation schemes of matrix converter (MC) topology and multi-module cascaded matrix converters (CMCs) for MV drives, and their application in commercial MV drives. © 2017 by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.
A 70 kVA/L air-cooled full-SiC three-phase inverter unit including power semiconductor modules, power capacitors, bus bars, gate drive circuits, a PWM wave generator and blower fans has been fabricated as a prototype for EV-use. SiC JFETs and SBDs of 1200 V were used. It has generated three-phase alternative power of 25 kVA to drive a 15 kW-class induction motor with only 190 W of dissipation. The module's temperature was at most 90°C.
This paper presents a model of two very common inverters, a traditional inverter and neutral point clamped inverter, for calculating the losses in function of the parameters of the inverter datasheet. The model allows simulating the inverter branch under any conditions, not only nominal sinusoidal, and monitoring its losses at the same time, so the most significant parameters could be determined in losses terms. The optimization of the losses in inverters could create an important energy saving since it is present in most of the power applications, mainly renewable energies. Obviously, the model is based on the electrical equations of both semiconductors inverters so the mathematical development is exposed. Finally, the model is validated by solving the equations analytically together with the model simulation under nominal sinusoidal environment.
This paper presents methods of loss calculation of IGBT modules, operating in two-level half-bridge inverters with square-wave output. The equations for calculating IGBT module losses for typical collector current waveforms using linearly interpolated datasheet curves are presented. Since this method is generally limited in accuracy, a better approximation of datasheet curves is introduced. In the second part the switching waveforms of experimental two-level half-bridge inverter based on two 6.5 kV Infineon IGBT modules are analysed.
This paper investigates an analytical power loss modeling method applied to a three-phase voltage source inverter, aiming to obtain an accurate inverter loss without the need of extensive experimental measurement, under the context of inverter efficiency optimization. Modeling of semiconductor is achieved through analytical equations for conduction and switching losses in the MATLAB/Simulink environment, using drain-to-source current and voltage waveforms. An experimental verification consisting of low power DC-source, three-phase MOSFET inverter and brushless dc motor, is conducted to validate the loss model. It is found that the modeled power loss is generally consistent with experimental verification at incremental dc-link voltage from 12V-18V, with inverter efficiencies in the 94.7-97.4% and 94.5-97.2% regions, respectively. The developed loss model can be used in fast inverter-motor drive power loss optimization where losses depend on circuit parameters and operating point of motor, which are accounted for in the developed model.
This paper presents an integrated framework for modelling inverter performance and evaluating power devices in hybrid electric vehicle drives. Based in MATLAB/Simulink, it uses a novel method of decoupling the device and inverter simulation to maintain high accuracy of power losses and devices temperatures, and achieve faster than real time inverter simulation. An illustration is given for a full hybrid vehicle for different driving cycles. Device models are included for silicon carbide Schottky diodes as well as silicon IGBTs and PIN diodes. Evaluation of the new material devices is performed, to estimate the potential performance gains achievable. The simulation framework offers the potential to rapidly improve the inverter and powertrain design process, and to evaluate device selection quickly.