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Noise-Vibration (NVH) Analysis & Reduction in Traction Motors-PMSMs at the Design Stage

Tata Motors, Ltd.-Vishwanatha K. Rao
  • Technical Paper
  • 2020-01-1509
To be published on 2020-06-03 by SAE International in United States
Various electric propulsion systems are used in the industrial field. Recently, research focused on permanent magnet synchronous motors (PMSMs) because of their several advantages. There are various method to reduce Noise and Vibration of traction at the Design Stage of Motor. Noise reduction has constituted a difficult study point for the last years. A great part of this acoustic noise has electromagnetic origin. The harmonic spectrum of the PWM voltage supply is very rich and every frequency has direct effects on the motor acoustics and also Various Torques effect on the Motor, In this paper, the Design Stage of Electric Motor Describe the Design Specifications and Calculations For reduce Harmonics and unwanted Torque (Electromagnetic Forces) for NVH reduction. Such as two winding methods for the interior permanent-magnet synchronous motor for vehicle traction: concentrated winding and distributed winding. Both have merits and demerits, and both influences the motor’s performance. Also the paper presents and analyses the experimental acoustic noise of AC motors controlled by drives using different PWM techniques. Five criteria are taken into account: motor…
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Simulation Process for the Acoustical Excitation of DC-Link Film Capacitors in Highly Integrated Electrical Drivetrains

AVL LIST GmbH-Julian Pohn
BMW Group-Maximilian Herrnberger, Jakob Bonart, Roland Lichtinger
  • Technical Paper
  • 2020-01-1500
To be published on 2020-06-03 by SAE International in United States
The advancing electrification of the powertrain is leading towards new challenges in the field of acoustics. Film capacitors used in power electronics are a potential source of high-frequency interfering noise since they are exposed to voltage harmonics. These voltage harmonics are caused by semiconductor switching operations that are necessary to convert the DC voltage of the battery into three-phase alternating current for the electrical machine. In order to predict the acoustic characteristics of the DC-link capacitor at an early stage of development, a multiphysical chain of effects has to be addressed to consider electrical and mechanical influences. In this paper, a new method to evaluate the excitation amplitude of film capacitor windings is presented. The corresponding amplitudes are calculated via an analytical force based on electromechanical couplings of the dielectric within film capacitors. As a next step, these calculated excitation amplitudes can be used in a FE simulation by applying volumetric strains on capacitor windings. This allows to consider the structural dynamic properties of different capacitor geometries. In order to lower the computational costs, a…
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Impact of Engine Oil Detergent on Low Speed Pre-Ignition (LSPI) and Fuel Economy Performance

Afton Chemical Corp.-Ashutosh Gupta, Mark Devlin
  • Technical Paper
  • 2020-01-1424
To be published on 2020-04-14 by SAE International in United States
Low Speed Pre-Ignition (LSPI), also referred to as Stochastic Pre-Ignition (SPI), Superknock or Megaknock is an undesirable combustion phenomenon that limits the fuel economy, drivability, emissions and durability performance of modern turbocharged gasoline engines. Numerous studies have previously reported that the frequency of LSPI is sensitive to engine oil composition. One of these drivers is the concentration of Calcium, which is usually delivered in the form of a detergent in the additive package. Switching to completely all-Magnesium detergent and/or severely limiting the concentration of Ca in the engine oil have recently been proposed as potential means to reduce LSPI. In this work, we evaluate the impact of detergent type on LSPI performance as well as on other performance that the modern engine oil needs to deliver. Particularly the impact of detergent type on Fuel Economy performance is evaluated. To ensure a rigorous and high precision measurement of the impact of engine oil on fuel economy, representative of real-world conditions, under well-controlled conditions, the ASTM D8114 test (Sequence VIE) was used to quantify fuel economy performance…
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An Evaluation of Future Topologies and Architectures for Highly Reliable Electrical Distribution Systems

University of Kassel-Ludwig Brabetz, Mohamed Ayeb, Janis Lehmann, Benjamin Löwer
  • Technical Paper
  • 2020-01-1296
To be published on 2020-04-14 by SAE International in United States
Within the scope of the development of autonomous vehicles, the continuous introduction of automated driving functions considerably increases the mandatory reliability requirements of the electrical power supply, and consequently of the electrical distribution system (EDS). In addition, the overall rising number of electrical functions in future vehicles leads to significantly higher electrical power demands, while strict cost, weight and packaging constraints must be upheld. Current developments focus mostly on the improvement of the conventional EDS, e.g. by adding redundancies, enhancing physical robustness, or redimensioning critical components. New approaches address predictive power management, better diagnostic capabilities, and, the subject of this paper, new topologies and architectures. Alternative topologies are derivations of the conventional tree structure, as well as ring- or linear-bus-based zonal architectures, which feature in part distributed storage devices or semiconductor switches that rearrange the power paths in case of a fault. The presented approach is a method for both the systematical description of EDS topologies and architectures, and the assessment of their reliability. It is based on a data model designed for a simple…
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Starting Process Control of a 2-Cylinder PFI Gasoline Engine for Range Extender

Tongji University-Minglong Li, Ran Zhang, Xingyu Zeng, Weiqi Ding, Weiang Mao, Shaoye Jin, Rufeng Xu, Dengke Yuan, Zongjie Hu, Zaimin Zhong, Liguang Li
  • Technical Paper
  • 2020-01-0315
To be published on 2020-04-14 by SAE International in United States
With the increasing worldwide concern on environmental pollution, battery electrical vehicles (BEV) have attracted a lot attention. However, it still couldn’t satisfy the market requirements because of the low battery power density, high cost and long charging time. The range-extended electrical vehicle (REEV) got more attention because it could avoid the mileage anxiety of the BEVs with lower cost and potentially higher efficiency. When internal combustion engine (ICE) works as the power source of range extender (RE) for REEV, its NVH, emissions in starting process need to be optimized.In this paper, a 2-cylinder PFI gasoline engine and a permanent magnet synchronous motor (PMSM) are coaxially connected. Meanwhile, batteries and load systems were equipped. The RE co-control system was developed based on Compact RIO (Compact Reconfigurable IO), Labview and motor control unit (MCU). Focused on the starting process, the effects of first firing speeds, throttle control strategies and coolant temperatures were tested.The results show that the higher first firing speed is preferred without obvious torque fluctuation, and longer throttle switching duration to high load results in…
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Improved Potential Field-Based Collision Avoidance Control for Autonomous Vehicles

PATAC-Shiliang Shang, Mengge Guo
Shanghai Jiao Tong University-Weishun Deng, Kaijiong Zhang, Xi Zhang, Fan Yu
  • Technical Paper
  • 2020-01-0123
To be published on 2020-04-14 by SAE International in United States
Limiting factors for autonomous vehicle (AV) to be widely used are not only technical, but also psychological. Considering the psychological feelings of drivers during switching manned to unmanned driving status, this paper proposes an algorithm about avoiding collisions combining driver psychological feelings for AVs. The confidence-limit-distance of the driver is experimentally obtained by many real track tests which require the test driver to approach the obstacle as close as possible. The confidence-limit-distance from driver is defined as the distance between the obstacle and the last steering point allowed for the psychological limit of the driver to avoid collisions. Based on Artificial Potential Field (APF), a road potential field is accordingly established to characterize the characteristics and boundary constraints of the real road. To express the different influences of relative speed and direction on the driver's psychological feeling, the confidence potential field is established based on a two-dimensional normal distribution combining von Mises distribution. The second-order Taylor expansions of road potential field and confidence potential field are firstly introduced into the cost functions for model predictive…
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Design of a Flexible Hybrid Powertrain Using a 48 V-Battery and a Supercapacitor for Ultra-Light Urban Vehicles

IFP School-Ouafae El Ganaoui-Mourlan, El Hadj Miliani, Daniel Carlos Da Silva, Matthieu Couillandeau, Charlie Gonod, Guillaume Miller
  • Technical Paper
  • 2020-01-0445
To be published on 2020-04-14 by SAE International in United States
Global warming has put the transport sector, a major contributor of CO2 emissions, under high pressure to improve efficiency. In this context, ultra-light vehicles weighting less than 500 kg, as well as hybrid powertrains, are nowadays seen as promising development trends. The design process of the powertrain of a vehicle combining the advantages of the two concepts is presented in this paper. Through a performance study based on a simple MATLAB model, and mathematical simulation, a proposal is made. A powertrain using a battery and supercapacitor 48V dual power source network, two electric motors and clutches to switch between conventional, parallel, series and full electric modes proves to be an interesting system in terms of performance and costs. A simulation study conducted on a scenario with different outcome possibilities showed that high modularity of the system allows to achieve fuel efficiencies equivalent to approximately 3 l/100 km on the Artemis cycle. Finally, integration, packaging and cost are considered and some hints for further powertrain efficiency improvements are presented.
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Virtual Switches and Indicators in Automotive Displays

General Motors LLC-Scott Rush
  • Technical Paper
  • 2020-01-1362
To be published on 2020-04-14 by SAE International in United States
This paper presents recent advances in automotive microprocessor, operating system, and supporting software technology that supports regulatory and/or functional safety graphics within vehicle cockpit displays. These graphics include “virtual switches” that replace physical switches in the vehicle, as well as “virtual indicators” that replace physical indicator lights. We discuss the functional safety design process and impacts to software and hardware architecture as well as the software design methods to implement End-To-End [E2E] network protection between different ECUs and software processes. We also describe hardware monitoring requirements within the display panel, backlighting, and touch screen and examine an example system design to illustrate the concepts.
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The Development of the Method to Analyze User Preference of Routing from the Probe Data in Cloud

Toyota Motor Corporation-Xin Jin, Taiki Nakamura
ZENRIN DataCom Co., Ltd.-Toshinori Takayama, Ai Yashiro
  • Technical Paper
  • 2020-01-0740
To be published on 2020-04-14 by SAE International in United States
Routing quality always dominates the top percentage which is around 20% of the complaints of in-vehicle navigation. It is because that the routing algorithm is common which is not adaptive to individual user’s preference. For example, some users prefer the quickest route while some prefer the routes quick and comfort. The reason is that the legacy in-vehicle navigation is an embedded system which has the common navigation software. As the connected vehicles rapidly spread, in the case of Toyota it is announced that all the new model vehicles in JP, CN, US will be connected, routing function switches from the embedded device to the cloud in which there are plenty of probe data uploaded from the vehicles. These probe data make it possible to analyze user preference and customized routing profile adaptive to each single user. This paper describes the method to analyze the user preference from the probe data uploaded to the cloud. The method includes data collection, the analysis model of routes scoring and user preference. As well the evaluation of the model…
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Comparison of EVSE Charge Management Systems for Limited Electrical Infrastructure

Sacramento Municipal Utility District-Dwight MacCurdy, Carol D. Kay, Karun Kumar, Deepak J. Aswani
  • Technical Paper
  • 2020-01-0532
To be published on 2020-04-14 by SAE International in United States
The installed cost of EV charging stations can vary widely depending on site specific conditions and the number and type of EV charging stations (EVSE) to be installed. The cost can exceed $10,000 per EVSE if panel or switch gear upgrades are needed or if trenching is required. These infrastructure costs can pose a significant barrier to EV adoption for fleet operators or for employers who wish to provide EV charging for employees. Smart EVSE can play a role in managing the infrastructure and installation cost of EVSE. Such products can enable charging when there are limitations in electrical capacity. Three types of smart EVSE are tested and compared: 1) fully autonomous/local control, 2) networked/cloud managed control, and 3) a hybrid of local and cloud managed control.