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2016-05-01
Journal Article
2015-01-9145
Abdullah AL-Refai, Osamah Rawashdeh, Rami Abousleiman
Abstract Lithium-Ion batteries are the standard portable power solution to many consumers and industrial applications. These batteries are commonly used in laptop computers, heavy duty devices, unmanned vehicles, electric and hybrid vehicles, cell phones, and many other applications. Charging these batteries is a delicate process because it depends on numerous factors such as temperature, cell capacity, and, most importantly, the power and energy limits of the battery cells. Charging capacity, charging time and battery pack temperature variations are highly dependent on the charging method used. These three factors can be of special importance in applications with strict charging time requirements or with limited thermal management capabilities. In this paper, three common charging methods are experimentally studied and analyzed. Constant-current constant-voltage, the time pulsed charging method, and the multistage constant current charging methods were considered.
2016-04-05
Technical Paper
2016-01-1221
Kiyoshi Ito, Takumi Shibata, Takashi Kawasaki
Drive motors such as for hybrid vehicles and electric vehicles require windings that can endure use at high voltages. The winding is the main part for which insulation needs to be assured in the motor operating environment. In addition, consideration should also be given to insulation damage during molding. Conventional motors generally secure insulation by using the two parts of the winding and insulating paper to assure insulation. However, this increases the motor space factor and hinders size reduction. A new high-voltage winding formed by molding extruded resin onto an enamel insulating layer was developed to reduce the number of insulating parts and enhance motor performance. Extrusion molding of polyetheretherketone (PEEK) resin onto an insulating layer realized a winding that can withstand the molding load during motor manufacture, secures durability for the automobile motor operating environment and can maintain high-voltage characteristics.
2016-04-05
Technical Paper
2016-01-1235
Johannes Gragger, Alessandro Zanon, Michele De Gennaro, Jonathan Juergens, Antonio Fricassè, Luca Marengo, Igor Olavarria, Jutta Kinder
The widespread of hybrid and battery electric vehicles is vital for the future low-carbon mobility. In this context the delivery of affordable and efficient electric motor technologies together with high energy density storage devices are key aspects to enable the mass market take-off of electrified vehicles. The objective of this paper is to provide the scientific community with the results and design features of an innovative and rare-earth free electric motor technology based on the synchronous reluctance machine concept. This technology is capable to provide sufficient power density and higher driving cycle energy efficiency compared to the current state-of-the-art rare-earth permanent magnet synchronous machines used for automotive applications. The motor is designed to be integrated within a hatchback rear driving axle vehicle, achieving the maximum energy efficiency in urban operational conditions.
2016-04-05
Technical Paper
2016-01-1219
Hua Bai, Matt McAmmond, Juncheng Lu, Qi Tian, Hui Teng, Alan Brown
Most of the present EV on-board chargers utilize three-stage design, e.g., AC/DC rectifier, DC to high-frequency AC inverter, and AC to DC rectifier, which will limit the wall-to-battery efficiency to ~94%. Instead of using the regular three-stage design, the matrix converter could directly convert the grid AC to high-frequency AC thereby saves one stage and potentially increases the system efficiency, however, the control strategy will be more complex. In addition to the efficiency requirement, the demand on high-power density design requires high switching frequency, which challenges the present power electronics design based on Silicon devices. As the new-generation semiconductor switches, wide-bandgap (WBG) devices, such as GaN HEMTs and SiC MOSFETs recently draw much attention. Compared to conventional Si MOSFETs or IGBTs, WBG devices exhibit much shorter turn-on/off time intervals, close-to-zero reverse recovery loss and much smaller conduction loss.
2016-04-05
Technical Paper
2016-01-1232
Peng Yi, Zechang Sun, Xinjian Wang
The different choices of IGBTs’ switching frequency of the PMSM inverter used in vehicle lead to different energy loss of the inverter. Meanwhile, they lead to different phase current harmonics, which result in different energy loss of the PMSM. Compared with traditional switching frequency design method, the optimal design method considers the loss of the PMSM as well as the inverter, proposing a switching frequency design method of the minimum system loss. Firstly, by establishing the IGBT model (Hefner Model) and the PMSM analytical model, obtain PMSM phase currents under different conditions and different switching frequencies through simulating. The inverter energy loss under different conditions is obtained at the same time. Then, the phase currents under different conditions are applied to the finite element model thus the distribution of the magnetic field strength H and the magnetic flux density B is obtained, so that the PMSM loss can be calculated.
2016-04-05
Technical Paper
2016-01-1229
Douglas Cesiel, Charles Zhu
Manufacturers have introduced several types of electric vehicles that utilize on-board charging systems; including Battery Electric Vehicles (BEV), Extended Range Electric Vehicles (EREV), and Plug-in Hybrid Electric Vehicles (PHEV). These vehicles include an on-board power conversion system that allows the DC propulsion battery to be charged using energy from the AC power grid. The primary component within the charging system is an AC/DC conversion module known as the On-Board Charger (OBC). The efficiency of the charging system directly effects overall vehicle efficiency. Losses in the charging system correspond to AC grid energy that is consumed but does not contribute to increasing the battery state of charge. Reducing losses also reduces the work required of the cooling system during battery charging, and this further improves overall efficiency. Thus, OBC efficiency improvement was an important objective for GM.
2016-04-05
Technical Paper
2016-01-1233
Kensuke Sasaki, Apoorva Athavale, Brent Gagas, Takashi Fukushige, Takashi Kato, Robert Lorenz
Variable flux permanent magnet synchronous machines (VF-PMSMs) have been designed by using finite element analysis (FEA) to evaluate speed-torque properties considering magnetization state (MS) manipulation capability. This paper presents a analytical model to estimate speed-torque properties of VF-PMSMs and a process to find preferred magnet dimensions to obtain a specified speed-torque capability requirement in order to accelerate the design process. This model uses an equivalent circuit based analysis to obtain the magnet flux linkage, d-axis inductance (Ld) and demagnetization border in the id-iq plane to maintain a desired MS on the magnet edge, considering VF-PMSM design requirements for magnetization state (MS) manipulation. This model is applied to predict speed-torque properties for several machine designs with a fixed topology, a fixed stator diameter and a fixed stacking length, and varying magnet dimensions, namely, thickness and width.
2016-04-05
Technical Paper
2016-01-0022
Kenta Morishima, Shigeru Thomas Oho, Satoshi Shimada
A virtual power window control system was built in order to look into and demonstrate applications of microcontroller models. A virtual ECU simulated microcontroller hardware operations and executed step-by-step its control program in binary digital code. Thus, production-ready codes of ECUs are of primary interest in this research. The mechanical system of the power window, the DC motor to lift the window glass, the H-bridge MOSFET drivers, and the current sensing circuit to detect window locking are also modeled. This means that the hardware system of the control system was precisely modeled in terms of mechanical and circuit components. By integrating these models into continuous and discrete co-simulation, the power window control system was analyzed in detail from the microscopic command execution of the microcontroller to the macroscopic motion of the window mechanism altogether.
2016-04-05
Technical Paper
2016-01-1230
Takaoki Ogawa, Atsushi Tanida, Toshifumi Yamakawa, Masaki Okamura
The physical property of silicon power semiconductor is approaching limit of material. That is used for motor control of electric motor car, which is Hybrid Vehicle (HV) and Plug-in Hybrid Vehicle (PHV), Fuel Cell Vehicle (FCV) and so on. With the aim of real practical use after 2020, new material power semiconductor Silicon Carbide (SiC) is being developed. That is expected as a key technology for further improving fuel efficiency for electric motor car. We made power control unit (PCU) that adopted the Silicon Carbide (SiC) power semiconductor experimentally this time. SiC power semiconductors have low power loss caused by low conduction loss and low switching loss when switching on and off as described in our papers. We evaluated the power semiconductors temperature at which the boost converter was operated continuously. The switching frequency was 10 kHz and 20 kHz.
2016-04-05
Technical Paper
2016-01-1227
Osamu Kitazawa, Takaji Kikuchi, Masaru Nakashima, Yoshiki Tomita, Hajime Kosugi, Takahisa Kaneko
Toyota Motor Corporation has developed the new compact-class hybrid vehicle(HV). This vehicle incorporates a new hybrid system for the improvement of fuel efficiency. For this system, a new Power Control Unit (PCU) is developed. The feature of the PCU is downsizing, lightweight, and high efficiency. In expectation of rapid popularization of HV, the aptitude for mass production is also improved. The PCU, which plays an important role in the new system, is our main focus in this paper. Its development is described.
2016-04-05
Technical Paper
2016-01-1234
Toshikazu Sugiura, Atsushi Tanida, Kazutaka Tamura
The SiC power semiconductor is expected to improve the fuel efficiency of gasoline-electric hybrids and other vehicles with electric powertrains, such as PHVs, EVs and FCVs. The use of SiC power semiconductors in a wider range of models was considered, and the FC Boost Converter of the FC bus was chosen. The SiC diodes which are called the SiC Schottky Barrier Diodes (SiC-SBDs) were installed in the FC Boost Converter which controls the voltage of electricity from the FC stack for FC bus. In the electric current range and temperature of main use, it was confirmed that the forward characteristics (Vf) of SiC-SBDs were smaller than Si-PiN diodes (Si-PiNDs) of conventional products. In other words, the electric conduction loss is less than Si-PiNDs. In SiC-SBDs, a recovery electric current is largely reduced in comparison with conventional Si-PiNDs. As a result, the recovery loss of SiC-SBDs was reduced 90 percent.
2016-04-05
Technical Paper
2016-01-1228
Faizul Momen, Khwaja M. Rahman, Yochan Son, Peter Savagian
A permanent magnet AC (PMAC) motor is used to design the propulsion system of Chevrolet Bolt battery electric vehicle (BEV). Magnets are buried inside the rotor in two layer ‘V’ arrangement. The double layer magnet arrangement improves rotor saliency resulting in improved motor performance. The double layer arrangement also provides flexibility in the rotor design to lower torque ripple and stator teeth radial force, the major drivers for airborne acoustic noise and vibration. The Chevrolet Bolt electric machine rotor design additionally optimizes the magnet placement between the adjacent poles asymmetrically to further lower torque ripple and radial force. Similar to Gen1 Chevrolet Spark BEV electric motor, a pair of small slot is stamped in each rotor pole near the rotor outer surface to lower torque ripple and radial force.
2016-04-05
Technical Paper
2016-01-1218
Tsuyoshi Iguchi
Evaluation testing of current, temperature and so on in the Power Control Unit (PCU) of a Hybrid Electric Vehicle (HEV) under driving conditions had previously been conducted by operating the actual Permanent Magnet Synchronous Motor (PMSM) that is the target of control. For this reason, at times when the actual motor was unavailable, it was impractical to perform a PCU evaluation. The goal of this research was to implement testing of PCU current and temperature under driving conditions by constructing test methodologies that utilize a motor emulator instead of an actual motor. In order to construct a motor emulator able to simulate a current equivalent to that of an actual motor, a motor model simulator capable of processing a detailed PMSM Finite Element Analysis (FEA) model was developed, together with a 100kW-class phase current controller able to regulate the drive current and regenerative current under driving conditions.
2016-04-05
Technical Paper
2016-01-1223
Yukiya Kashimura, Yuki NEGORO
A second-generation power control unit (PCU) for a two-motor hybrid system is proposed. An optimally designed power module, which is a key component of the PCU, is applied to increase heat-resistant temperature, while the basic structure of the first generation is retained and the power semiconductor chip is directly cooled from the single side. In addition to the optimum design, by decreasing the power loss as well as increasing the heat-resistant temperature of the power semiconductors (IGBT: Insulated Gate Bipolar Transistor and FWD: Free Wheeling diode), the proposed PCU has attained 25% higher power density and 23% smaller size compared to first-generation units, maintaining PCU efficiency (fuel economy). To achieve a high yield rate in the power module assembly process, a new screening technology is adopted at the initial stage of power module manufacturing.
2016-04-05
Technical Paper
2016-01-1224
Yosuke Osanai, Masaki Wasekura, Hideo Yamawaki, Yusuke Shindo
The power loss reduction of power control units (PCUs) for hybrid vehicles (HVs) is essential to improve their fuel economy. The loss of the power devices (IGBTs and diodes) used in the PCU is about 20% of the whole power loss of HV, so it is important to reduce the loss. Also the trade-off between the loss reduction and the voltage surge reduction is one of the issues. The rising speed of the gate voltage of IGBT should be slowed to reduce the voltage surge between the corrector and emitter, while the gate voltage of IGBT should be raised rapidly to reduce the loss. We adopted the two-level turn-on method for the gate voltage of IGBT to improve the trade-off. This idea is already known widely. However it is difficult to realize the control with high accuracy and the high speed. A circuit is designed for the feedback control with high speed operation. The improvement of the trade-off between the loss reduction and the voltage surge reduction was achieved.
2016-04-05
Technical Paper
2016-01-0015
Eldad Palachi, Fariz Saracevic, Amit Fisher
Connected vehicles provide suppliers and OEMs new opportunities to improve their customer experience and offer new services. Yet, in this new era of Internet of Things (IoT), OEMs and suppliers are expected to expand their engineering efforts beyond the vehicle itself. We present a new Rapid Application Development (RAD) service offered by IBM, called IBM Internet of Things Workbench. This is a visual tool, currently offered as IBM Bluemix service that allows engineers to design the overall architecture and interactions between the various IoT entities such as devices, cloud applications and services, mobile clients and asset management systems. IoT Workbench abstracts the messaging details and generates code skeletons for the cloud applications as well as for simulating devices.
2016-04-05
Technical Paper
2016-01-1220
Sinisa Jurkovic, Khwaja M. Rahman, Peter Savagian, Robert Dawsey
The Cadillac CT6 plug-in hybrid electric vehicle (PHEV) power-split transmission architecture utilizes two motors. One is an induction motor type while the other is a permanent magnet AC (PMAC) motor type referred to as motor A and motor B respectively in this paper. Bar-wound stator construction is utilized for both the motors. Induction motor A winding is connected in delta and PMAC motor B winding is connected in wye. The choice of an induction motor for motor A enables a lower overall system cost and a rare earth free design while delivering desired performance. Low spin loss design of an induction rotor as compared to a permanent magnet rotor, especially at higher speeds, is the major enabler for the choice of an induction motor for motor A for this application. This paper presents advantages of induction machines (IMs) in automotive industry in the context of this application and an approach to design a cost-effective electric machine.
2016-02-01
Technical Paper
2016-28-0197
Nithin Alex John, Mona Sherki, Sanjay A Patil
Abstract New generation automobiles are equipped with power windows which eases the passenger’s effort in moving the vehicle windows up and down. Many of them are stuffed with advanced features like automatic up/down option for ensuring functionality with a single press of the switch. Even though it adds comfort to driver & passenger, inadvertent use of power window can be fatal if a person’s body part gets trapped inside. An effective solution for this problem is anti-pinch mechanism, which releases the object safely just when it gets trapped. It detects the object trapped and immediately moves the window down so that trapped object will get released easily. The anti-pinch algorithm used in this project is based on the “Method of Monitoring Movable Element”, method monitor traveling distance of a power window pane. In order to achieve this different from conventional techniques we are using Ultrasonic sensor.
2015-09-15
Technical Paper
2015-01-2412
Tao Yang, Serhiy Bozhko, Greg Asher
This paper aims to develop a general functional model of multi-pulse Auto-Transformer Rectifier Units (ATRUs) for More-Electric Aircraft (MEA) applications. The ATRU is seen as the most reliable way readily to be applied in the MEA. Interestingly, there is no model of ATRUs suitable for unbalanced or faulty conditions at the moment. This paper is aimed to fill this gap and develop functional models suitable for both balanced and unbalanced conditions. Using the fact that the DC voltage and current are strongly related to the voltage and current vectors at the AC terminals of ATRUs, a generic functional model has been developed for both symmetric and asymmetric ATRUs. The developed functional models are validated through simulation and experiment. The efficiency of the developed model is also demonstrated by comparing with corresponding detailed switching models. The developed functional model shows significant improvement of simulation efficiency, especially under balanced conditions.
2015-04-14
Technical Paper
2015-01-1202
Weimin Zhang, Saeed Anwar, Daniel J. Costinett, Fred Wang
Abstract A cost-effective SiC based hybrid switch and an improved inductor design procedure for boost converter in electric vehicles (EVs) and hybrid electric vehicles (HEVs) are presented in this paper. The feasibility of a hybrid switch using low power SiC MOSFET and high power Si IGBT is investigated to provide a cost-effective and failure-resistant method to employ the fast switching characteristics of SiC devices. The operation of the hybrid switch is tested in double pulse test experiment and compared with the single IGBT. Additionally, the boost inductor design is discussed, which allows the optimization of weight and power loss across different core materials. An improved powder core inductor design procedure is presented to avoid the iterative design procedure provided by the manufacture. Both the powder material and nanocrystalline material are considered in the inductor design procedure.
2015-04-14
Journal Article
2015-01-1209
Zhengyu Liu, Thomas Winter, Michael Schier
Abstract This paper presents the development of a novel direct coil cooling approach which can enable high performance for electric traction motor, and in further significantly reduce motor losses. The proposed approach focuses on bypassing critical thermal resistances in motor by cooling coils directly in stator slots with oil flow. Firstly, the basic configuration and features are shown: sealed stator slots to air gap, pressure reservoirs on both side of the slots and slot channels for oil flow. The key to enhance thermal performance of the motor here is based on introducing fluid guiding structure in the slot channels. Next, heat transfer in the channel with guiding structure is investigated by CFD and compared with bare slot channel without guiding structure. For studying the effectiveness of proposed cooling concept, numerical analysis is conducted to compare it with HEV favored oil impingement cooling.
2015-04-14
Technical Paper
2015-01-1203
Subhashree Rajagopal, Sebastien Desharnais, Balamurugan Rathinam, Upendra Naithani
Abstract Electromagnetic brakes are found in a variety of applications. They offer tremendous advantages including: absence of fading, high braking torque and controllability. However they suffer from decreasing torque at low and high speeds. In this study, a novel concept of permanent magnet eddy-current brake is proposed that maintains a flat braking torque profile over a broad speed range. The principle is analytically investigated and numerically validated through finite element simulations using MAXWELL. It is demonstrated that a usably flat braking torque profile can be achieved by altering the path of eddy-currents by magnetic field orientation, thereby affecting the apparent rotor resistance.
2015-04-14
Journal Article
2015-01-1201
Mohammad Anwar, Monty Hayes, Anthony Tata, Mehrdad Teimorzadeh, Thomas Achatz
Abstract The Chevrolet Volt is an electric vehicle with extended-range that is capable of operation on battery power alone, and on engine power after depletion of the battery charge. First generation Chevrolet Volts were driven over half a billion miles in North America from October 2013 through September 2014, 74% of which were all-electric [1, 12]. For 2016, GM has developed the second-generation of the Volt vehicle and “Voltec” propulsion system. By significantly re-engineering the traction power inverter module (TPIM) for the second-generation Chevrolet Volt extended-range electric vehicle (EREV), we were able to meet all performance targets while maintaining extremely high reliability and environmental robustness. The power switch was re-designed to achieve efficiency targets and meet thermal challenges. A novel cooling approach enables high power density while maintaining a very high overall conversion efficiency.
2014-09-16
Technical Paper
2014-01-2117
Michael L. Zierolf, Thomas Brinson, Andrew Fleming
Abstract Recent emphasis on optimization of engine technologies with ancillary subsystems such as power and thermal management has created a need for integrated system modeling. These systems are coupled such that federated design methods may not lead to the most synergetic solution. Obtaining an optimal design is often contingent on developing an integrated model. Integrated models, however, can involve combining complex simulation platforms into a single system of systems, which can present many challenges. Model organization and configuration control become increasingly important when orchestrating various models into a single simulation. Additionally, it is important to understand such details as the interface between models and signal routing to ensure the integrated behavior is not contaminated or biased. This paper will present some key learnings for model integration to help alleviate some of the challenges with system-based modeling.
2014-09-16
Technical Paper
2014-01-2113
Fei Gao, Serhiy Bozhko, Greg Asher
Abstract Stability is a great concern for the Electrical Power System (EPS) in the More Electric Aircraft (MEA). It is known that tightly controlled power electronic converters and motor drives may behave as constant power loads (CPLs) which may produce oscillations and cause instability. The paper investigates the stability boundaries for dc multi-source EPS under different power sharing strategies. For each possible strategy the corresponding reduced-order models are derived. The impedance criterion is then applied to study the EPS stability margins and investigates how these margins are influenced by different parameters, such as main bus capacitance, generator/converter control dynamics, cabling arrangements etc. These results are also illustrated by the root contours of reduced-order EPS models. Theoretical results achieved in the paper are confirmed by the time-domain simulations.
2014-09-16
Technical Paper
2014-01-2181
Christopher Ian Hill, Chris Gerada, Paolo Giangrande, Serhiy Bozhko
Abstract This paper presents the initial development of a Modelica Library for Electro-Mechanical Actuator system analysis. At present two main system components are described, these are the Power Electronic Converter and Electric Machine, although further components will be added. These models provide the user with the ability to simulate Electric Machine and Power Electronic Converter systems including physical effects, losses and fault conditions. Established modelling programs such as Saber and MATLAB SimPowerSytems are often unable to provide all the aspects required to accurately simulate real systems in an easy to use, flexible manner. Therefore this paper shows how Modelica has been used to create versatile models able to simulate many practical aspects such as Power Electronic Converter losses and Power Electronic Converter faults, Electric Machine losses and Electric Machine faults.
2014-09-16
Technical Paper
2014-01-2176
Niloofar Rashidi Mehrabadi, Bo Wen, Rolando Burgos, Dushan Boroyevich, Chris Roy
Abstract The development of the concepts, terminology and methodology of verification and validation is based on practical issues, not the philosophy of science. Different communities have tried to improve the existing terminology to one which is more comprehensible in their own field of study. All definitions follow the same concept, but they have been defined in a way to be most applicable to a specific field of study. This paper proposes the Verification, Validation, and Uncertainty Quantification (VV&UQ) framework applicable to power electronic systems. Although the steps are similar to the VV&UQ frameworks' steps from other societies, this framework is more efficient as a result of the new arrangement of the steps which makes this procedure more comprehensible. This new arrangement gives this procedure the capability of improving the model in the most efficient way.
2014-09-16
Technical Paper
2014-01-2139
Serhiy Bozhko, Seang Shen Yeoh, Fei Gao, Tao Yang, Christopher Hill
Abstract The paper reports the control design for an aircraft electric starter-generator system based-on high-speed permanent magnet machine operated in a flux-weakening mode and controlled by an active front-end rectifier. The proposed system utilizes advances of modern power electronics allowing the use of novel machine types and the introduction of controlled power electronics into the main path of energy flow. The paper focuses on control design for such system and includes development of flux weakening control of high-speed permanent magnet machine and droop control of the system output dc-link current. The achieved analytical design results and the expected system performance are confirmed by time-domain simulations.
2014-09-16
Technical Paper
2014-01-2141
Christine Ross, Michael Armstrong, Mark Blackwelder, Catherine Jones, Patrick Norman, Steven Fletcher
Abstract The Turboelectric Distributed Propulsion (TeDP) concept uses gas turbine engines as prime movers for generators whose electrical power is used to drive motors and propulsors. For this NASA N3-X study, the motors, generators, and DC transmission lines are superconducting, and the power electronics and circuit breakers are cryogenic to maximize efficiency and increase power density of all associated components. Some of the protection challenges of a superconducting DC network are discussed such as low natural damping, superconducting and quenched states, and fast fault response time. For a given TeDP electrical system architecture with fixed power ratings, solid-state circuit breakers combined with superconducting fault-current limiters are examined with current-source control to limit and interrupt the fault current.
2014-09-16
Technical Paper
2014-01-2156
Arthur V. Radun
Abstract There is a continuing need to simulate power electronic circuits that include magnetic components. It is necessary to determine the interaction of the magnetic component with the rest of the power electronic system so that a dynamic circuit model of the magnetic components including material saturation and iron losses is required. Also, the magnetic component model must be valid when the magnetic component's excitation is not sinusoidal. A dynamic magnetic circuit model derived from Maxwell's equations along with useful theorems for building circuit models from the structure of the magnetic device is reviewed. The developed circuit models are general including magnetic saturation and iron losses. Simulation results for a DC/DC converter employing a conventional gapped inductor and a gapped coupled inductor are presented.
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