| EPE 2021 - Dialogue session - E-Mobility | ||
| You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2021 ECCE Europe - Conference > EPE 2021 - Topic 08: Electric Vehicle Propulsion Systems and their Energy Storage > EPE 2021 - Dialogue session - E-Mobility | ||
 | [return to parent folder] | |
 | A Highly Dynamic 600 V / 300 A Battery Emulator for Testing of Automotive Electric Drive Trains
By Jan-Philipp VON KLITZING | |
|
Abstract: In this paper, a highly dynamic 80 kW battery emulator for test bench applications is proposed. The novelty is the accurate battery impedance emulation for frequencies up to 20 kHz. This allows for a reproduction of parasitic oscillations between battery and device under test as well as an emulation of voltage ripples due to switching frequency and motor harmonics.To identify the requirements, a common battery behavior was analyzed in the frequency domain. The result was applied for adapting not only the performance of the control strategy but also for adapting the hardware of the emulator.To achieve accurate battery emulation, a design of two serially connected switching converters with different power rating and dynamic behavior, an LC filter optimized regarding the output impedance, and a physical interface for emulating the parasitic inductance of the battery was adapted. For the control strategy, a full state feedback controller that replicates the battery resistance by choosing appropriate poles was used.Simulation results are given to show that sub-millisecond oscillations can occur between battery and electric drive system and that the proposed emulator achieves almost ideal representation of the battery model when used in this application.
| ||
| | A Phase Shedding Control Technique for Ripple Minimisation for EV Fast DC Charging Applications
By Mohammed A. ALHARBI | |
|
Abstract: This paper introduces an off-board fast DC charger for electric vehicles (EVs) with a proposed control scheme that aims to produce an output charging current with the lowest ripple possible and to improve the overall efficiency of the system. The proposed configuration of the DC charger is based on multiple modules of dc-dc multiphase interleaved buck converters (IBCs). Using phase-shedding control, the DC charger can process only a fraction of the total rated power based on the required charging power. This leads to a reduction in the losses resulting in an improvement in the overall charging system. As demonstrated by simulation results, the proposed methodology considerably minimizes the ripple of the output charging current, which directly affects the lifespan of the EV battery.
| ||
| | Battery electric vehicle (BEV) powertrain modelling and testing for real-time control prototyping platform integration
By Maria Raluca RAIA | |
|
Abstract: This paper presents a method to virtually evaluate the performances and energy consumption of a battery electric vehicle (BEV) powertrain, whose propulsion is assured by a wound rotor synchronous machine. For that, the powertrain's subsystems are modeled using Energetic Macroscopic Representation (EMR) concept and adapted for later implementation in a real-time control prototyping platform. Two levels of complexity are developed for the propulsion motor, resulting in two BEV powertrain models. The resulting powertrain models are validated by comparing the simulation results with the experimental measurements obtained from a real Renault ZOE Q90 car. In order to evaluate the accuracy of the models under study, two driving cycles profiles, a mixed urban and extra-urban profile and a highway one, are chosen to characterise the system behaviour under normal and maximum vehicle speed conditions. Furthermore, as the developed powertrain is dedicated to real-time applications, the simulation time of the two proposed models are compared in order to choose the one that computes results with desired accuracy in a reduced amount of time.
| ||
| | Battery Management System Evaluation within a Complete Electric Vehicle Model with Software-in-the-Loop and Hardware-in-the-Loop Approaches
By Matthieu PONCHANT | |
|
Abstract: A detailed battery pack model has been developed within Simcenter Amesim by Siemens Industry Software. The model illustrates the Battery Management System (BMS) control development process from Model in the Loop (MiL), Software in the Loop (SiL) to Hardware in the Loop (HiL). The battery pack model has been integrated in a validated vehicle model, which corresponds to an existing vehicle developed by Voltia, named the Voltia eVan. This originally diesel engine powered light duty trucks have been electrified. The electrified version has been tested on the roller bench at the Eindhoven University of Technology.The interest of detailing the battery pack model is to have access to a multiple virtual temperature and voltage sensors, which allows validating the balancing methodologies that could be integrated in a BMS. A real-time analysis of the model has been conducted to ensure the model is compatible with the control constraint of the BMS.Finally, the complete model has been connected to a functional BMS in order to validate the approach. For that purpose, several BMS functions have been implemented in the control model developed with MATLAB/Simulink, such as the state of charge (SOC) estimation, the cell balancing, the charge/discharging and the thermal management. Once the cosimulation in SiL environment has been validated, a test on HiL platform has been done in real-time condition in order to reproduce realistic cell balancing and to study charging strategies, which are key functions to ensure better lifetime of the battery.
| ||
| | Battery-Integrated Modular Multilevel Converters for Automotive Drive-train Applications
By Arvind BALACHANDRAN | |
|
Abstract: The automotive industry has grown considerably over the last century consequently increasing greenhouse gas emissions and thus contributing towards increase in the average global temperature. It is thus of paramount importance to increase the use of alternative energy sources. Electric vehicles have gained popularity over the last decade. However, a major concern with electric vehicles is their range. The range of an electric vehicle is limited by the battery pack, in particular, the weakest cell of the pack. One method of increasing the available energy from the battery pack is by introducing more electronics. Modular multilevel converters, with their modular concept, could be a viable solution. The concept of battery-integrated modular multilevel converters (BI-MMC) for automotive applications is explored. In particular, the impact of the number of cascaded cells per submodule is investigated, considering battery losses, DC-link capacitor losses, and the converter losses. Furthermore, an optimization of the DC-link capacitors and the selection of MOSFET switching frequency is presented in order to minimize the total losses.
| ||
| | Design and Implementation of a Multifunctional 6-phase Interleaved Bidirectional DC/DC Converter for Battery Electric Vehicle Applications
By Sajib CHAKRABORTY | |
|
Abstract: This paper proposes a new multifunctional 6-phase Interleaved Bidirectional DC/DC Converter (IBC)topology, which can perform two distinct functionalities independently as function 1: a 6-phase IBC fortraction/braking modes and function 2: a typical level-2 fast onboard vehicular battery charger (OBC)for charging/discharging modes. In function 2, the 6-phase IBC translates into a 3-phase Active FrontEnd (AFE) AC/DC converter and a 3-phase DC/DC converter for transferring electrical energy fromGrid-to-Vehicle (G2V) and Vehicle-to-Grid (V2G). The flexible control schemes are developed andautomatically switched from propulsion modes (traction/braking) to the G2V and/or V2G modes. Theproposed converter and its functionalities are analyzed by using MATLAB/Simulink®. Furthermore, afield-programmable gate array-based (FPGA) programming board of dSPACE MicroLabBox, is utilizedto validate the control compensators (i.e., z-domain) in Software-in-the-Loop (SiL) testbench. Finally,experimental results validate the function 1 mode operation of the proposed multifunctional convertertopology.
| ||
| | Design and operation of a DC/DC converter to integrate energy storage into a railway traction system
By Alberto RODRIGUEZ | |
|
Abstract: The use of Energy Storage Systems (ESSs) can improve the energy efficiency of railway systemsassisting the traction system and recovering regenerative braking energy. In this paper, a mediumfrequency modular converter using SiC MOSFETs is analyzed to interface the ESS with a 1500 Vdccatenary and the load.The use of SiC MOSFETs allows the increase of the switching frequency and the reduction of the size,volume and weight of the transformer. A modular topology can provide redundancy, fault toleranceand enables system scalability. The maximum power and switching frequency of one module isestimated using commercially available semiconductors.
| ||
| | Development of a Dynamic Model of Lithium Ion Battery Pack for Battery System Monitoring Algorithms in Electric Vehicles
By Mussab NAJEEB | |
|
Abstract: The main objective of this paper is to develop an accurate and a self-corrective model for lithium ion battery pack, based on the analysis of properties and performance of equivalent circuit models of pack's cells and the use of artificial neural networks. This model is expected to meet the requirements for improving the accuracy of battery state estimation required for the monitoring algorithms of the battery system in electric vehicles. The use of the neural network will make it possible to adjust and correct modelling deviations and errors in equivalent circuit model parameters by comparing the modelled cells voltage and the measured voltage and generating modified model parameters based on this comparison. The validation experimental results show that the parameters of the modified model contributed to reducing the error rate in the cell voltage by approximately 70-80\% of the error rate in the equivalent circuit model voltage.
| ||
| | Digital Peak Current Mode Control Method for the Single-phase Bi-directional DC-AC Converter
By Naoto KOBAYASHI | |
|
Abstract: This paper presents a new digital peak current mode controlled single-phase bi-directional DC-AC converter with a current control method that reduces harmonic distortion of AC input/output current. The new current control method estimates and compensates for the deviation between current reference and inductor current in both DC-AC and AC-DC modes. The effectiveness of the proposed method for reducing harmonic current distortion is verified through experiments. Furthermore, the effectiveness of overshooting current suppression against sudden changes in the AC grid voltage is also verified.
| ||
| | Driving Cycle Analysis of the DC bus Current Ripple in Electric Vehicles
By Marius GENTEJOHANN | |
|
Abstract: In a battery electric vehicle (BEV), the traction inverter generates a current ripple overlaying the DC current, supplied by the high voltage battery. The overlaid current ripple increases the RMS and peak value of the DC bus current and may accelerate the aging of the battery. This paper derives and analyzes the current ripple in a driving cycle defined in the Worldwide Harmonized Light Vehicle Test Procedure (WLTP). The simulation model is validated by measurements from an automotive test bench. Different criteria to evaluate the current ripple are presented, compared, and discussed. Driving scenarios which produce a high ripple are detected. Finally, a sweep of switching frequency and DC link capacitance shows effective means to reduce the current ripple over the driving cycle.
| ||
| | Energy management and ECO-strategies modeling of electric bus fleets in Barcelona city
By Mohammed HASAN | |
|
Abstract: The paper studies the development of ECO-strategies, including ECO-driving, ECO-charging, and ECO-comfort, for fleets of electric buses traveling in two routes in Barcelona, route H16 and route L33, in terms of their energy utilization, total cost of ownership and the impact on the grid. The efficacy of each ECO-strategy is evaluated with respect to the driving and climatic conditions. To evaluate the effects of climate, fleet simulations for Barcelona are run for mid-summer and mid-winter, in normal mode as well as for each of the ECO modes independently and all combined. To evaluate the effects of driving condition, two different routes with different average velocities and elevation profiles are considered. The fleet consists of four types of electric buses that are evaluated, including two 12m and two 18m buses, with different battery capacities and chemistries. Simulation results showed that the battery capacities for the 12m buses were more than sufficient to allow the buses to undertake two or three return trips before requiring charging. However, for the 18m buses the capacity was just sufficient to make one return trip in either of the routes being considered, not allowing much room for battery capacity degradation; thus, it is recommended to apply ECO-features to reduce the energy utilization rate, increase the number of charging points along the route, or increase the battery capacity. Results show that ECO-driving is more effective when the average velocity of the route is higher; thus, route H16 with an average route velocity of 2.64m/s shows no discernable energy savings, while route L33 with an average route velocity of 3.23m/s has 5\% ~ 7\% energy savings. Similarly, results show that ECO-comfort is optimized for cooling, with substantial energy savings of 23\% during summer and 18\% during winter. Finally, ECO-charging shows more energy savings for high charging c-rate; LTO batteries, with a c-rate of -5C showing 5\% ~ 6\% more savings than NMC battery, with a c-rate of -2.5C.
| ||
| | High-Performance Lithium Polymer Battery Pack for Real-World Racing Motorcycle
By Seyedreza AZIZGHALEHSARI | |
|
Abstract: This paper deals with the qualification testing to design a battery pack for a fully electric racing motorcycle. To obtain the best performance from the cells and considering the point that in this case the battery pack will be used in special racing condition, finding the best configuration and cells sequence to be connected together in that's configuration is very important to make the battery pack. To avoid impedance mismatching inside the modules and the final pack, electrochemical impedance spectroscopy, capacity test, and impulse current test has been used to select appropriate cells to be connected in strings and make a uniform and high-performance battery pack with the best configuration based on the categorized cells. Experimental results obtained from the cell to cell variation and also impedance measurement for each module prove the uniformity in impedance.
| ||
| | High-Power / High-Voltage (250 kW / 750V) SiC-Based Inverter for Electric Vehicles Applications
By Alexandre BATTISTON | |
|
Abstract: This paper presents the study and development of a high-power range traction inverter based on Full Silicon Carbide semiconductors. Implementing this breakthrough technology leads to an increase of the converter power density as well as its efficiency at high-frequency operation. Experimental characterization contributes to understanding of the power module switching behavior under different conditions with variation of some key parameters (gate driver resistor, load current, switching voltage, and stray inductor). Full-scale experimental results are provided to demonstrate a converter efficiency of 99\% and a power density of 28 kW/L.
| ||
| | Introducing state variance coupling within a multi-timescale Kalman filter for improved Li-ion battery capacity estimation convergence properties
By Filip MALETIC | |
|
Abstract: Estimators of lithium-ion battery states and parameters are usually divided in two coupled estimators realized in different timescales and based upon a battery equivalent circuit model (ECM). The estimator of battery state-of-charge (SoC) and ECM impedance parameters operates in the fast time scale, while the estimator of battery remaining charge capacity executes in the slow time scale. The paper presents an adaptive variance-coupling of SoC and capacity estimators aimed at improving the overall estimation performance in terms of accuracy and convergence speed. The emphasis is on presenting a detailed simulation analysis of the adaptively-coupled multi-timescale estimator features, including the convergence rate, parametrization robustness and capacity fade tracking.
| ||
| | Merging control for the hybrid energy storage subsystem of a Fuel-Cell Vehicle
By Alain BOUSCAYROL | |
|
Abstract: The Toyota Mirai is a fuel cell vehicle with a hybrid energy storage subsystem (battery and fuel cell). Its small-size battery has a limited state-of charge (SoC) variation of only 10\%. In order to reduce the fuel cell current peak, a new control scheme is proposed by merging two control laws. This merging offers a supplementary degree of freedom for the energy management strategy. In simulation, an increase the battery SoC variation by only 10\% leads to 20\% reduction of the fuel cell current for a WLTC driving cycle.
| ||
| | Modeling and Control Algorithm for a Modular GaN On-Board Charging System in Automotive Applications
By Tuan TRAN | |
|
Abstract: Due to the trend toward high-power on-board charging for Electric Vehicle (EV) powertrains, modular approach has been considered as an evident solution to achieve high power level, high efficiency, and reliability. However, it increases the complexity in both hardware and controller design. This paper proposes a comprehensive control strategy for GaN-modular charging system that can implement a precise constant current and constant voltage (CC/CV) charging profile and an excellent current sharing capability. Moreover, the efficiency of the proposed system is improved at a wide range of charging power by adopting a proper load shedding scheme. The circuit configuration consists of three individual modules of two-stage converter units, in which a totem pole power factor correction (PFC) and an isolated phase shift full bridge (PSFB) are selected as the front-end and back-end converter respectively. The average current mode control employed in PSFB stage not only maintains the constant current charging, but also automatically achieves current balancing among converter modules. The theoretical analysis and simulation results of a 11kW On-Board Charging (OBC) system have been presented to demonstrate the feasibility of proposed control method.
| ||
| | Modelling and bi-level control design of a SiC off-board charging system for battery electric buses with V2G capability
By Boud VERBRUGGE | |
|
Abstract: The recent breakthrough of battery electric buses (BEBs) in cities is leading to an increased load demand on the grid. Hence, smart and efficient charging infrastructure is required. Emerging wide bandgap (WBG) semiconductors, such as SiC and GaN, will enable future charging systems to operate at higher switching frequencies and therefore increase the efficiency of the charging process, while smart control algorithms will introduce new features like grid-to-vehicle (G2V) and vehicle-to-grid (V2G) operations to optimize the charging behaviour. Therefore, this paper proposes the modelling of a SiC technology-based off-board charging system for BEBs and the design of its bi-level controller. The low-level control system is used to ensure the battery's charging or discharging modes and to achieve the best total harmonic distortion (THD) and unity power factor (PF). Therefore, a linear and nonlinear simulation model are developed in MATLAB/Simulink to validate the PQ control theory-based performances. Additionally, a high-level charging management strategy (HL-CMS), based on a genetic algorithm (GA), provides an optimal charging (G2V) and discharging (V2G) scheduling for the entire charging/discharging process, considering the limits and requirements of the grid and bus operators. The results demonstrate that both controllers operate properly under different circumstances.
| ||
| | Observation and simulation of dynamic humidity in power converters for railwayapplications due to moisture diffusion in plastics
By Oskar SCHUSTER | |
|
Abstract: As environmental conditions influence the lifetime of power semiconductors, understandingmicroclimates inside converter cabinets is indispensable. We present data from railway converters andobserve dynamic humidity during operation. The results are explained by moisture diffusion in plasticsand validated by simulation and lead towards refined requirement specifications for powersemiconductors.
| ||
| | Single-stage isolated and bidirectional AC-DC converter suitable for ancillary services supply
By Marcos LAFOZ | |
|
Abstract: This work introduces a single-stage, bidirectional, isolated AC-DC converter with capability to supply ancillary services to grid. The converter is based on a simplification of the two-stage configuration where the power is transferred to grid by means of the low frequency voltage components of a voltage source inverter (VSI) meanwhile high frequency components are filtrated. In the proposed converter, high frequency components of the voltage are exploited for isolated power transfer to the DC by means of high Q resonant tanks and an additional phase-shift modulated active bridge. The proposed converter operates under similar principles to the two-stage configuration but with lower component count. This way, DC link capacitor is still present and designed to provide virtual inertia to the grid. The virtual inertia is achieved by an additional outer control loop that links frequency variations to the DC voltage control reference. Thus, the proposed converter is able to perform isolated and bidirectional AC-DC conversion and to provide the ancillary service of virtual inertia to the grid. The reliability of the system is demonstrated by means of simulation analysis of a 2.4 kW system.
| ||
| | Third phase solutions for compensation of second order harmonics in single-phase grid connected medium voltage converters
By Stefan SCHÖNEWOLF | |
|
Abstract: To eliminate bulky passive components used for the compensation of pulsating power flow in applications supplied from single phase AC grids, many solutions employing power electronics have been presented in the pertinent literature. One subclass of these solutions attaches an additional phase to an existing four-quadrant converter (4QC), to control a compensating power flow to a fully AC rated capacitor used as energy storage element. In this paper, it is shown that in medium voltage applications like railway traction, DC biased film capacitors reach significantly higher energy density compared to fully AC rated devices. For this reason, the existing topology is converted to a multilevel structure employing a DC biased capacitor as energy storage element, providing additional degrees of freedom for the current to be injected into the four-quadrant converter. By using an optimized current shape, the ratings for the passive components can be decreased at nearly constant semiconductor switch power compared to the original solution. Simulations results are shown to prove that the compensation works with the proposed solutions.
| ||