• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.456-465
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• 2019

PHEV(Plug in Hybrid Electric Vehicle) and BEV(Battery Electric Vehicle) equip high voltage batteries to drive motor and vehicle electric system. Those vehicle require OBC(On-Board Charger) for charging batteries and LDC(Low DC/DC Converter) for converting from high voltage to low voltage. Since the charger and the converter actually separate each other in electrical vehicles, there is a margin to reduce the vehicle weight and area of installation by integration two systems. This paper studies a 1.5kW LDC converter that can be integrated into an OBC using an isolated current-fed converter by simplifying the design of LDC transformers. The proposed LDC can control the final output voltage of the LDC by using a fixed arbitrary output voltage of the bidirectional buck-boost converter, so that Compared to the existing OBC-LDC integrated system, it has the advantage of simplifying the transformer design considering the battery voltage range, converter duty ratio and OBC output turn ratio. Prototype of the proposed LDC was made to confirm normal operation at 200V ~ 400V input voltage and maximum efficiency of 91.885% was achieved at rated load condition. In addition, the OBC-LDC integrated system achieved a volume of about 6.51L and reduced the space by 15.6% compared to the existing independent system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.665-670
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• 2004

This paper reviews the latest studies of the expander cycle Air Turbo Ramjet engine (ATREX) conducted in JAXA. First, a system analysis including the vehicle and trajectory was conducted to optimize the engine cycle and turbo-machine configuration. We selected the precooled turbo-jet cycle for a prototype engine using the near term technologies. Second, a system ground-firing test was conducted to verify a defrosting system for the precooler. Methanol injection with its particles atomization could compensate 80 % of pressure loss caused by the frost. Thirdly, a feasibility of carbon/carbon composites for the engine components was investigated by making complex shapes such as a heat exchanger and a plug nozzle. Basic technologies on the gas leakage, the junction and bonding were also studied. The end of the paper, some basic studies such as wind tunnel tests of a new type air inlet and a plug nozzle are described.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1033-1038
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• 2014

Electric vehicles should be connected to power system for charge and discharge of battery. Besides vehicle's battery is charged for a power source, it is also reversibly possible to provide power source from battery to power system. Researches on battery usage for regulation resources have been progressed and could cause cost increase excessively because they distribute regulation capacity equally without considering the battery wear cost of SOC, temperature, voltage and so on. This causes increase of grid maintenance cost and aggravate economical efficiency. In this paper it is studied that the cost could be minimized according to the battery condition and characteristic. The equation is developed in this paper to calculate the possible number of charge and discharge cycle, according to SOC level and weighting factors representing the relation between battery life and temperature as well as voltage. Thereafter, the correlation is inferred between the battery condition and wear cost reflecting the battery price, and the expense of compensation is decided according to the condition on battery wear-out of vehicle. In addition, using realtime error between load and load expectation, it is calculated how much regulation capacity should be provided.

• Journal of Power Electronics
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• v.11 no.4
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• pp.408-417
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• 2011

The plug-in hybrid electric vehicles (PHEVs) are specialized hybrid electric vehicles that have the potential to obtain enough energy for average daily commuting from batteries. The PHEV battery would be recharged from the power grid at home or at work and would thus allow for a reduction in the overall fuel consumption. This paper proposes an integrated power electronics interface for PHEVs, which consists of a novel Eight-Switch Inverter (ESI) and an interleaved DC/DC converter, in order to reduce the cost, the mass and the size of the power electronics unit (PEU) with high performance at any operating mode. In the proposed configuration, a novel Eight-Switch Inverter (ESI) is able to function as a bidirectional single-phase AC/DC battery charger/ vehicle to grid (V2G) and to transfer electrical energy between the DC-link (connected to the battery) and the electric traction system as DC/AC inverter. In addition, a bidirectional-interleaved DC/DC converter with dual-loop controller is proposed for interfacing the ESI to a low-voltage battery pack in order to minimize the ripple of the battery current and to improve the efficiency of the DC system with lower inductor size. To validate the performance of the proposed configuration, the indirect field-oriented control (IFOC) based on particle swarm optimization (PSO) is proposed to optimize the efficiency of the AC drive system in PHEVs. The maximum efficiency of the motor is obtained by the evaluation of optimal rotor flux at any operating point, where the PSO is applied to evaluate the optimal flux. Moreover, an improved AC/DC controller based Proportional-Resonant Control (PRC) is proposed in order to reduce the THD of the input current in charger/V2G modes. The proposed configuration is analyzed and its performance is validated using simulated results obtained in MATLAB/ SIMULINK. Furthermore, it is experimentally validated with results obtained from the prototypes that have been developed and built in the laboratory based on TMS320F2808 DSP.

• The Journal of Society for e-Business Studies
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• v.25 no.2
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• pp.1-14
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• 2020

ISO 15118 is an international standard that defines communication between electric vehicles and electric vehicle chargers. Plug & Charge (PnC) was also defined as a technology to automatically authenticate users when using charging services. PnC indicates automatic authentication technology where all processes such as electric vehicle user authentication, charging and billing are automatically processed. According to the standard, certificates for chargers and CPSs (Certificate Provisioning Services) should be under the V2G (Vehicle to Grid) Root certificate. In Korea, the utility company operates its own PKI (Public Key Infrastructure), making it difficult to provide chargers under the V2G Root Certificate. Therefore, a method that can be authenticated is necessary even when you have different Root Certificates. This paper proposes to apply cross-certificate technology to PnC authentication. Automatic authentication of Cross Certification is to issue a cross-certificate of the Root CA and include it in the certificate chain to proceed with automatic authentication, even if you have different Root certificates. Applying cross-certificate technology enables verification of certificates under other Root certificates. In this paper, the PnC automatic authentication and cross certificate automatic authentication is implemented, so as to proceed with proof of concept proving that both methods are available. Define development requirements, certificate profiles, and user authentication sequences, and implement and execute them accordingly. This experiment confirms that two automatic authentication are practicable, especially the scalability of automatic authentication using cross-certificate PnC.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.163-164
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• 2012

본 논문에서는 EV 또는 PHEV용 탑재형 배터리 충전기에 대하여 기술한다. 역률개선을 위한 PFC는 전류연속모드의 부스트 컨버터를 적용 하였으며, 스위칭 손실의 저감을 위해 영전압 스위칭이 가능한 위상천이 풀-브리지 DC-DC 컨버터를 사용하여 전기적인 절연 및 소자의 스위칭 스트레스를 줄이고 효율 또한 향상 시키고자 하였다. PSIM을 사용하여 시뮬레이션 하였으며 실험세트를 구성하고 결과를 분석하여 시스템의 효용성을 검증하였다.

• Journal of Institute of Convergence Technology
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• v.4 no.2
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• pp.67-70
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• 2014

Recently EU has been recognized that there is a difference of emission quantity between emission certification test mode and real-road driving test. Accordingly the European Commission is currently preparing to require real-road testing as part of the passenger car type-approval process in the EU. vehicle manufacturers from 2017 are expected to test new vehicles not only under laboratory conditions but also on the real-road, using PEMS equipment. Therefore the purpose of this study is to analyze the emission and Fuel Economy of CVS-75 mode test using chassis dynamometer and RDE test using PEMS equipment by PHEV passenger car.

• Journal of Power Electronics
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• v.13 no.3
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• pp.429-436
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• 2013

Online simulations are utilized to reduce time and cost in the development and performance optimization of plug-in hybrid electric vehicle (PHEV) and electric vehicles (EV) systems. One of the most important factors in an online simulation is the accuracy of the model. In particular, a model of a battery should accurately reflect the properties of an actual battery. However, precise dynamic modeling of high-capacity battery systems, which significantly affects the performance of a PHEV, is difficult because of its nonlinear electrochemical characteristics. In this study, a dynamic model of a high-capacity battery cell for a PHEV is developed through the extraction of the equivalent impedance parameters using electrochemical impedance spectroscopy (EIS). Based on the extracted parameters, a battery cell model is implemented using MATLAB/Simulink, and charging/discharging profiles are executed for comparative verification. Based on the obtained results, the model is optimized for a high-capacity battery cell for a PHEV. The simulation results show good agreement with the experimental results, thereby validating the developed model and verifying its accuracy.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.74-78
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• 2014

In this paper, we proposed Interference suppression method of between AMI system and EV charging system. IEC12139-1 and HomePlug GreenPhy are using 2-30Mhz frequency band in power line communication. Both method while using the same frequency band, interference occurs in the system of each other. In this paper, we experiment a way to suppress the interference through the channel separation using a Walsh code.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.10
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• pp.97-107
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• 2009

Recent technologies of the car are focused on improving vehicle's fuel efficiency and developing alternative energy sources. These technologies bring on the development of hybrid car. On the other hand, because of short driving distance, low efficiency of charging and high price, energy storage system need to improve the storage capability. It is very important to understand the existing technologies, grasp the existing patent and establish the technical target to improve the energy storage system. In this paper, technology trends of energy storage system of the hybrid car are analyzed. This study was based on the applied and registered patent in Korea, Japan, U.S.A and Europe until December 2008. The analyses are divided into two categories: a battery system and charging system of the hybrid car. The facts of the level of technology, trends of the R&D of leading companies, key patents, blank of the technology were analyzed. Finally the future R&D strategy of hybrid car are established.