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Development of New Power Control Unit with Small Size and Low Cost for Small Hybrid Vehicle with two-motor Hybrid System

Honda R & D-Yuichiro Ueno, Yasuhiko Kondo
Keihin Corp.-Kenichi Nonaka, Kenichi Takebayashi, Yukiya Kashimura
  • Technical Paper
  • 2020-01-0458
To be published on 2020-04-14 by SAE International in United States
A new power control unit (PCU) has been developed for 2020 Honda small hybrid vehicle with a 2-motor hybrid system. For small hybrid vehicles, downsizing and reducing costs of hybrid systems are main challenges. As such, the newly developed PCU was strongly required to be small and affordable. To satisfy the requirements for the PCU, new technologies and components have been introduced such as an all-in-one type intelligent power module (IPM) with integrated functions and reverse conducting IGBT (RC-IGBT), a new control sequence for voltage control unit (VCU), and PCU packaging to improve cooling performance. The new IPM has a printed-circuit board (PCB) equipped with an electric control unit (ECU) and gate drive circuits, 7 current sensors, and a power module with RC-IGBTs. This functional integration led to a reduction in the number of main electrical PCU assembly components from 9 in the previous PCU to 2 in the new PCU. In addition, the number of mounted parts on PCBs was reduced from 2,200 to 1,300 by means of the integration of ECU and gate…
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DC-link capacitor sizing in HEV/EV e-Drive Power Electronics System from Stability viewpoint

Ford Motor Company-Srikanthan Sridharan, Jun Kikuchi
  • Technical Paper
  • 2020-01-0468
To be published on 2020-04-14 by SAE International in United States
Selection of DC-link capacitance value in a HEV/EV e-Drive power electronics system depends on numerous factors including the capacitor’s required voltage/current ratings, power dissipation, thermal limitation, energy storage capacity, impact on system stability and so on. A significant challenge arises from capacitor selection based on DC-link stability due to the influence of multiple hardware parameters, control parameters, operating conditions and interaction effects among them. This paper introduces a methodology to determine the minimum required DC-link capacitance values that guarantee stable operation of the system in this multi-dimensional variable space. A broad landscape of the minimum capacitance values is also presented to provide valuable insights into the sensitivity of both hardware parameters and control parameters, on the overall system stability and understanding trade-offs and limits of these parameters. The target system example considered is a HEV e-Drive power electronics system consisting of one PWM DC/DC converter and two, three-phase PWM inverters, each inverter feeding an electrical machine. All the converters share the common dc-link at which the system stability is analyzed. Since the PWM converters are…
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SOLVING THE “telehandler problem”

SAE Truck & Off-Highway Engineering: February 2020

Maurice Ashmore
  • Magazine Article
  • 20TOFHP02_04
Published 2020-02-01 by SAE International in United States

Two-stage overcenter valves create stability in machines with highly dynamic loads.

A common challenge engineers face in the application of counterbalance or overcenter valves is machines with a high degree of load dynamics. Vehicles with slender booms, multiple booms, wear pads with varying frictional forces or pneumatic tires are all subject to higher levels of load dynamics. Concrete pumps are a common example as they require multiple long, slender booms to deliver concrete to the work site. Rough-terrain forklifts or telescopic handlers with pneumatic tires are other examples.

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Novel electrochemical capacitors with high-energy density using intercalated metal-organic framework electrodes

(TOYOTA Central R&D Labs., Inc.)-Nobuhiro Ogihara
  • Technical Paper
  • 2019-01-2260
Published 2019-12-19 by SAE International in United States
The energy-density improvement of capacitors while maintaining high power, long-term-cycle stability and safety is challenging. Asymmetric capacitors using non-faradaic and intercalation electrodes are proposed in order to achieve this. However the reported asymmetric capacitors with graphite-based negative electrode have a safety risk, which is an internal short circuit due to Li deposition when further high-energy density is performed. Here asymmetric capacitors consisting of intercalated metal-organic frameworks (iMOFs) negative operating potential range of 0.5-1.0 V vs. Li/Li+ that enable Li deposition reduction and activated carbon positive electrodes is proposed to construct a high volumetric energy (ca. 60 Wh L-1) and power densities with safety.
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Nylon Provides Building Block for Electronic Devices

  • Magazine Article
  • TBMG-35514
Published 2019-11-01 by Tech Briefs Media Group in United States

Thin nylon films are several 100 times thinner than human hair and could thus be attractive for applications in bendable electronic devices or for electronics in clothing. The researchers developed a method to fabricate ferroelectric nylon thin-film capacitors by dissolving nylon in a mixture of trifluoroacetic acid and acetone and solidifying it again in vacuum. They were able to realize thin nylon films that are typically only a few hundred nanometers thick.

Graphene Lid Extends Photoemission Electron Microscopy to Liquids

  • Magazine Article
  • TBMG-34753
Published 2019-07-01 by Tech Briefs Media Group in United States

By capping liquids with graphene (an ultrathin sheet of pure carbon), researchers can easily image and analyze liquid interfaces and the surface of nanometer-scale objects immersed in liquids. In the imaging technique known as photoemission electron microscopy (PEEM), ultraviolet light or X-rays bombard a sample, stimulating the material to release electrons from a region at or just beneath its surface. Electric fields act as lenses, focusing the emitted electrons to create an image.

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Power Electronic Noise-Simulation Measurement Comparison

AVL LIST GmbH-Markus Resch, Thomas Resch, Stephan Brandl
AVL Software and Functions Gmbh-Peter Olbrich, Hartwig Reindl
Published 2019-06-05 by SAE International in United States
A growing development of hybrid or fully electrical drives increases the demand for an accurate prediction of noise and vibration characteristics of electric and electronic components. This paper describes the numerical and experimental investigation of noise emissions from power electronics, as one of the new important noise sources in electric vehicles.The noise emitted from the printed circuit board (PCB) equipped with multi-layer ceramic capacitors (MLCC) is measured and used for the calibration and validation of numerical model. Material properties are tuned using results from experimental modal analysis, with special attention to the orthotropic characteristic of the PCB glass-reinforced epoxy laminate sheet (FR-4). Electroacoustic excitation is pre-calculated using an extension of schematic-based EMC simulation and applied to the structural model. Structural vibrations are calculated with a commercial FEM solver with the modal frequency response analysis. Sound radiation is simulated using the wave-based approach (WBT). Simulation and experimental results are compared in a frequency range up to 10 kHz.The developed simulation methodology can successfully identify the main noise sources from the equipped PCB. Critical peak noise responses…
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The ‘Relativity’ of High Q Capacitors

  • Magazine Article
  • TBMG-34557
Published 2019-06-01 by Tech Briefs Media Group in United States

For many high-power RF applications, the “Q factor” of embedded capacitors is one of the most important characteristics in the design of circuits. This includes products such as cellular/telecom equipment, MRI coils, plasma generators, lasers, and other medical, military, and industrial electronics.

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Features of Modeling Thermal Development Processes of the Vehicle Engine Based on Phase-Transitional Thermal Accumulators

Belarusian National Technical University-Heorgi Kukharonak
Donbas National Academy of Civil Engineering & Architecture-Valery Aleksandrov
Published 2019-04-02 by SAE International in United States
The utilization of different types of energy in phase-transitional thermal accumulators and its further use for thermal development of different subsystems of hybrid vehicles enables to significantly increase their operational efficiency. The system of the combined utilization of thermal and electrical energy in phase-transitional thermal accumulators (TA) is offered. To charge TA, it uses thermal energy of exhaust gas, a coolant and motor oil of the internal combustion engine and electrical energy which is utilized by energy recovery system when braking the vehicle. It consists of consecutive stages of heat accumulation when charging TA from different energy sources of the hybrid vehicle, its storage and use for rapid heating of vehicle separate subsystems. The main heat and power characteristics of system components and heat accumulating materials used in phase-transitional TA have been justified. Schemes and designs of a physical model to utilize electrical energy using high-capacity condensers for charging phase-transitional TA have been offered. The results of experimental and computational studies show theoretical comparison of the main indicators of the developed system in charging phase…
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Detection of Presence and Posture of Vehicle Occupants Using a Capacitance Sensing Mat

Clemson University-Rahul Prasanna Kumar, Yunyi Jia
Ford Motor Company-David Melcher, Pietro Buttolo
Published 2019-04-02 by SAE International in United States
Capacitance sensing is the technology that detects the presence of nearby objects by measuring the change in capacitance. A change in capacitance is triggered either by a change in dielectric constant, area of overlap or distance of separation between the electrodes of the capacitor. It is a technology that finds wide use in applications such as touch screens, proximity sensing etc. Drawing motivation from such applications, this paper investigates how capacitive sensing can be employed to detect the presence and posture of occupants inside vehicles. Compared to existing solutions, the proposed approach is low-cost, easy to deploy and highly efficient. The sensing system consists of a capacitance-sensing mat that is embedded with copper foils and an associated sensing circuitry. Inside the mat the foils are arranged in rows and columns to form several touch-nodes across the surface of the mat. The system segregates row and column capacitances from each other and computes their tensor product to generate grayscale capacitance-sensing images. The images are real-time pictorial representation of the capacitance of each touch-node. When the mat…
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