• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.3
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• pp.191-200
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• 2019

This study proposes a hardware-in-the-loop simulation (HILS) system based on National Instruments' PXI platform to test power management and operation strategies for DC microgrids (MGs). The HILS system is developed based on the controller HIL prototype, which involves testing the controller board in hardware with a real-time simulation model of the plant in a real-time digital simulator. The system provides an economical and effective testing function for research on MG systems. The decentralized power management strategy based on the DC bus signaling method for DC MGs has been developed and implemented on the HILS platform. HILS results are determined to be similar to those of the off-line simulation in PSIM software.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.527-528
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• 2016

현대인들이 가장 많이 사용하는 대중교통은 버스이다. 이에 DB를 통해 많은 이용횟수를 보이는 출, 퇴근시간대에 급행버스를 배치하여 보다 편리한 생활을 위해 다음과 같은 프로젝트를 진행하게 되었다. 서울시를 중심으로 이용객의 시간별, 일별, 월별 승하차 인원을 조사하고 지역인구와 승하차 인원의 연관관계를 탐색하였다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.768-778
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• 1993

The system is designed for the production and processing of feed, fertilizer, sugar , and grain. It can be used to weigh and transport automatically their pellet, power or nonstickness materials. In this system, we use discontinuous totalising automatic weighing instruments to weigh materials. It is a closed-cycle control system controlled by industrial controlling computer STD bus. The system used for processing grain and feed can improve the quality of products , carry out scientific management, increase productivity and decrease the intensity of labour

• Land and Housing Review
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• v.2 no.3
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• pp.217-226
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• 2011

The Seoul Metropolitan Government is striving to minimize the amount of traffic according to the supply of apartment houses along with the solution of housing shortage for the low income people through high density development near the subway area. Therefore, a stronger policy is necessary to control the traffic of the passenger cars in a subway area for the successful high density development focusing on public transportation, and especially, the estimation of the demand of cars with high reliability is necessary to control the demand of parking such as the limited supply of parking lot. Accordingly, this study developed car ownership forecasting model using Look-up Table among category analyses which are easy to be applied and have high reliability. The estimation method using Look-up-Table is possible to be applied to both measurable and immeasurable types, easy to accumulate data, and features the flexible responding depending on the changes of conditions. This study established Look-up-Table model through the survey of geographical location, the scale of housing, the accessible distance to a subway station and to a bus station, the number of bus routes, and the number of car owned with data regarding 242 blocks in Seoul City as subjects.

• International Journal of Automotive Technology
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• v.2 no.2
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• pp.39-45
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• 2001

Hydrogen is seen as one of the important energy vectors of the next century. Hydrogen as a renewable energy source, provides the potential for a sustainable development particularly in the transportation sector. Hydrogen driven vehicles reduce both local as well as global emissions. The laboratory of transporttechnology (University of Gent) converted a GM/Crusader V-8 engine for hydrogen use. Once the engine is optimised, it will be built in a low-floor midsize hydrogen city bus for public demonstration. For a complete control of the combustion process and to increase the resistance to backfire (explosion of the air-fuel mixture in the inlet manifold), a sequential timed multipoint injection of hydrogen and an electronic management system is chosen. The results as a function of the engine parameters (ignition timing. injection timing and duration, injection pressure) we given. Special focus is given to topics related to the use of hydrogen as a fuel: ignition characteristics (importance of electrode distance), quality of the lubricating oil (crankcase gases with high contents of hydrogen), oxygen sensors (very lean operating conditions), noise reduction (configuration and length of inlet pipes). The advantages and disadvantages of a power regulation only by the air to fuel ratio (as for diesel engines) against a throttle regulation (normal gasoline or gas regulation) are examined. Finally the goals of the development of the engine are reached: power output of 90 kW, torque of 300 Nm, extremely low emission levels and backfire-safe operation.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.540-549
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• 2018

This paper proposes the method of active distribution network expansion planning considering distributed generation integration and distribution network reconfiguration. The distribution network reconfiguration is taken as the expansion planning alternative with zero investment cost of the branches. During the process of the reconfiguration in expansion planning, all the branches are taken as the alternative branches. The objective is to minimize the total costs of the distribution network in the planning period. The expansion alternatives such as active management, new lines, new substations, substation expansion and Distributed Generation (DG) installation are considered. Distribution network reconfiguration is a complex mixed-integer nonlinear programming problem, with integration of DGs and active managements, the active distribution network expansion planning considering distribution network reconfiguration becomes much more complex. This paper converts the dual-level expansion model to Second-Order Cone Programming (SOCP) model, which can be solved with commercial solver GUROBI. The proposed model and method are tested on the modified IEEE 33-bus system and Portugal 54-bus system.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.5
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• pp.313-320
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• 2018

This study proposes a new voltage balancer with bidirectional DC-DC converter function. The proposed balancer can serve as a voltage balancer and a bidirectional DC-DC converter. Thus, the balancer can be applied to battery management systems or fast chargers in electric vehicles (EVs) charging stations while balancing bipolar DC bus voltages. The proposed system has unlimited voltage balancing range unlike the conventional voltage balancing control using a three-level DC-DC converter. A comparison of the voltage balancing range between the proposed and conventional scheme is explored to confirm this superiority. Simulation and experimental results are provided to validate the effectiveness of the proposed system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.257-265
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• 2011

As the competitive market system has been introduced to the electrical power trade, the priority concern would be that the price of electrical power should be reasonable. It is because, when this rule is solid, we can avoid the distortion of competition and assure the greater efficiency in management. LMP(Locational Marginal Price) means marginal price at each bus. This components consist of energy, loss and congestion cost. At this point, the LMP result that is calculated by traditional model is changeable by the location of the slack and can not be used in bilateral Transaction. This paper proposed algorithm is proved its rationality and credibility by comparing the result of the simulation of virtual 6_bus system that is calculated by traditional method, and showed that the LMP components are changed according to the Transaction Strategy. Furthermore, It shows the effect of additional congestion cost on the transmission line that has bottle neck frequently by simulation.

• Journal of Electrical Engineering and Technology
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• v.4 no.1
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• pp.1-12
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• 2009

In recent years, integration of new distributed generation (DG) technology in distribution networks has become one of the major management concerns for professional engineers. This paper presents a dynamic methodology of optimal allocation and sizing of DG units for a given practical distribution network, so that the cost of active power can be minimized. The approach proposed is based on a combined Genetic/Fuzzy Rules. The genetic algorithm generates and optimizes combinations of distributed power generation for integration into the network in order to minimize power losses, and in second step simple fuzzy rules designs based upon practical expertise rules to control the reactive power of a multi dynamic shunt FACTS Compensator (SVC, STATCOM) in order to improve the system loadability. This proposed approach is implemented with the Matlab program and is applied to small case studies, IEEE 25-Bus and IEEE 30-Bus. The results obtained confirm the effectiveness in sizing and integration of an assigned number of DG units.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.8
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• pp.2436-2448
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• 1996

This paper presents the development of three types of network performance manager for IEEE 802.4 token bus networks that are a part of Manufacturing Automation Protocol(MAP). The performance managers attempt to keep the average data latency below a certain level specified for each priority class. All of the three performance managers are based on a set of fuzzy rules incorporating the knowledge on the relationship between data latency and parameters of the priority mechanism. These Fuzzy Network Performance Managers(FNPMs) have been evaluated via discrete event simulation to demonstrate their efficacy.