• Journal of Power Electronics
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• v.18 no.6
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• pp.1771-1779
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• 2018

Modern trams with a super capacitor have gained a lot of attention in recent years due to its reliability, convenience, energy conservation and environmental friendliness. Because of its special charging characteristic, the traditional charging structure and control strategy cannot satisfy its charging requirements. This paper presents a new charging topology for fast charging modern trams with a super capacitor and it designs a controller using continuous control set model predictive control (CCS-MPC). There are three contributions in this paper. First, a new charging structure is designed and its mathematics model is derived. The cascade structure is adopted instead of the parallel structure to simplify the control process and to keep the rated power of the controllable part low. Second, a MPC control strategy is proposed to satisfy the charging characteristic. The optimal control signal can be obtained by solving the designed optimization problem. The optimal control signal is related to the discrete control action. In addition, mapping between the continuous control signal and the discrete control action is designed. Third, a semi-physical experimental platform is built to verify the proposed topology and control method. The simulation model and experiment platform are built to verify the correctness of the new structure and its control method. The results obtained show that the new topology can work effectively.

• Smart Media Journal
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• v.9 no.1
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• pp.67-74
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• 2020

As the demand of electric vehicles has been increased recently, their related industries are developing. In particular, the market of electric vehicles charging infrastructure is expanding rapidly and users have much demand in convenience of electric vehicles charging site. Because an charging site using electric pole of KEPCO can make use of that installed nearby public parking lots, there are many commercial construction and convenient facilities near around it. In this situation, users can do shopping or their personal business during charging. In this paper, we proposed the design of charging platform for electric vehicles to support LBS for users to do shopping or personal business conveniently.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.8
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• pp.343-352
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• 2017

IEC62541, known as OPC-UA, is a standard communication protocol for Smart Grid (SG) and Smart Factory application platform. It was accepted as an IEC standard (IEC62541) in 2011 by IEC TC57, and is extending range of application as collaborating with other standrads. The government's policies to popularize EVs ("Workplace Charging Challenge"), the number of Electric vehicle which try to be charging in the factory is expected to increase. In this situation, indiscreet and uncontrolled EV charging can lead to some problems, such as excess of the peak demand capacity. Therefore, EVs, which is charging in SFs, must be monitoring and controlling to avoid and reduce peak demand. However, the standards for EVs charging differ from the standards for SFs. In other words, to increase the ease of use for drivers, and reduce risk for enterprise, we have needs of study to develop the protocols or to provide interoperability, for EVs charging in SFs. This paper deals with a EV charging management platform installing in a smart factory. And this platform can be easily integrated as part of SF management software. The main goal of this paper is to implement EV management system based on IEC61851 and IEC62541.

• The Journal of Korea Robotics Society
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• v.1 no.2
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• pp.117-124
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• 2006

In this paper, we develope the navigation system for patrol robots in indoor environment. The proposed system consists of PDA map modelling, a localization algorithm based on a global position sensor and an automatic charging station. For the practical use in security system, the PDA is used to build object map on the given indoor map. And the builded map is downloaded to the mobile robot and used in path planning. The global path planning is performed with a localization sensor and the downloaded map. As a main controller, we use PXA270 based hardware platform in which embedded linux 2.6 is developed. Data handling for various sensors and the localization algorithm are performed in the linux platform. Also, we implemented a local path planning algorithm for object avoidance with ultra sonar sensors. Finally, for the automatic charging, we use an infrared ray system and develop a docking algorithm. The navigation system is experimented with the two-wheeled mobile robot using North-Star localization system.

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.2
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• pp.95-101
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• 2012

In order to supply emotion service depending on user's emotional change in a mobile environment, various researches have been carried. This paper discusses a protocol for wireless charging and an embedded platform of the mobile emotional sensing device which supports that. Wireless charging process relieves user's vexatious task to charge the emotional sensing device. To support wireless charging, there are one basestation and several mobile devices. Basestation coordinates and controls the devices over wireless communication, as well as supplies energy. For 1:N communication we defines the network whose superframe is classified into four categories: a network join superframe, a charging request superframe, a charging superframe and an inactive superframe. Physical layer provides how to supply energy to the devices and communicate physically. Mobile device is equipped with energy charged circuits, which correspond with the defined energy supplying method, as well as bidirectional communication circuits. Mobile device monitors and analyzes its own battery status, and is able to send a request packet to basestation. Therefore, it can be charged before its battery is exhausted without user's perception.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.3
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• pp.179-179
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• 2004

In the near future we can expect a change in charging the Internet service. The flat charging maybe replaced with a usage-based charging. In line with this movement, we propose a method of charging the assured-quality Internet services for the next generation network by introducing a UBC (usage-based charging) scheme over the conventional flat charging platform. First, we investigate the attribute of elastic traffic generated by assured services in IP network. Next, we propose a new method to relate the bandwidth usage with the pricing for the elastic traffic, which is based partially on the usage rate of the network bandwidth. Next, we propose a charging function for elastic traffic, which is applicable to any type of assured Internet services. Finally, we discuss the implication of the work via simple numerical experiments.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.3
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• pp.21-28
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• 2004

In the near future we can expect a change in charging the Internet service. The flat charging maybe replaced with a usage-based charging. In line with this movement, we propose a method of charging the assured-quality Internet services for the next generation network by introducing a UBC (usage-based charging) scheme over the conventional flat charging platform. First, we investigate the attribute of elastic traffic generated by assured services in IP network. Next, we propose a new method to relate the bandwidth usage with the pricing for the elastic traffic, which is based partially on the usage rate of the network bandwidth. Next, we propose a charging function for elastic traffic, which is applicable to any type of assured Internet services. Finally, we discuss the implication of the work via simple numerical experiments.

• Journal of Power Electronics
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• v.7 no.4
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• pp.318-327
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• 2007

The design and performance analysis of a power factor corrected (PFC), single-phase, single switch flyback buck-boost ac-dc converter is carried out for low power battery charging applications. The proposed configuration of the flyback buck-boost ac-dc converter consists of only one switch and operates in discontinuous current mode (DCM), resulting in simplicity in design and manufacturing and reduction in input current total harmonic distortion (THD). The design procedure of the flyback buck-boost ac-dc converter is presented for the battery charging application. To verify and investigate the design and performance, a simulation study of the flyback buck-boost converter in DCM is performed using the PSIM6.0 platform. A laboratory prototype of the proposed single switch flyback buck-boost ac-dc converter is developed and test results are presented to validate the design and developed model of the system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.328-338
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• 2017

In this paper, a zero torque control scheme adopting current sharing function (CSF) used in integrated Switched Reluctance Motor (SRM) drive with DC battery charger is proposed. The proposed control scheme is able to achieve the keeping position (KP), zero torque (ZT) and power factor correction (PFC) at the same time with a simple novel current sharing function algorithm. The proposed CSF makes the proper reference for each phase windings of SRM to satisfy the total charging current of the battery with zero torque output to hold still position with power factor correction, and the copper loss minimization during of battery charging is also achieved during this process. Based on these, CSFs can be used without any recalculation of the optimal current at every sampling time. In this proposed integrated battery charger system, the cost effective, volume and weight reduction and power enlargement is realized by function multiplexing of the motor winding and asymmetric SR converter. By using the phase winding as large inductors for charging process, and taking the asymmetric SR converter as an interleaved converter with boost mode operation, the EV can be charged effectively and successfully with minimum integral system. In this integral system, there is a position sliding mode controller used to overcome any uncertainty such as mutual inductance or DC offset current sensor. Power factor correction and voltage adaption are obtained with three-phase buck type converter (or current source rectifier) that is cascaded with conventional SRM, one for wide input and output voltage range. The practicability is validated by the simulation and experimental results by using a laboratory 3-hp SRM setup based on TI TMS320F28335 platform.

• Journal of Internet Computing and Services
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• v.18 no.5
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• pp.123-131
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• 2017

With the rapid growth of mobile services, the various charging methods for mobile data have emerged in the mobile service market. Among them, network operators have begun to provide the zero-rating without any extra charge for the data that use the specific mobile application & services. Zero-rating, the free mobile data services by the network operators provoked many platform operators to confront business opportunity and risk. Though the platform operators are in urgent need of the strategy planning that considers business environments, any research endeavors explaining zero-rating and platform does not exist. Moreover, the analyses of potential effects of zero-rating on the business acts of platform operators has not been performed. Therefore, the study aims to identify the potential business opportunity and risk to prepare the various strategic countermeasure in platform operators' shoes. The study might enable the researchers to properly understand zero-rating and platform, and be utilized as a reference in planning the business strategy of the platform operators.