• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.388-394
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• 2015

The inrush current of a large inductive load can be reduced with a soft starter; however, the large inrush current caused by simultaneous bulk starts (SBSs) cannot be effectively reduced. In order to reduce the high inrush current and voltage sag owing to the SBSs of large capacity inductive loads within a power network, a novel hybrid sequential start control system is proposed, implemented on embedded systems, and evaluated with a testbed in this study. From the experimental and simulation results of the proposed control system, the inrush current could be effectively restricted below the maximum current capacity of a power distributing board. Moreover, with the proposed system, power cost typically dictated by the peak power consumption can be fairly reduced, and the quality of the power system connected to the inductive loads can be efficiently increased.

• Journal of IKEEE
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• v.16 no.2
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• pp.109-115
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• 2012

We propose a control system consisted of TRIAC PWM module and sequential start control system attenuating voltage-dip and inrush current caused by starting of inductive load network. To minimize the high voltage-dip and inrush current induced from a large capacity inductive load, we developed a TRIAC PWM module. And we also developed a sequential start control system preventing simultaneous starting of the inductive loads within a same power network. According to the experimental results with the proposed control system, the voltage-dip and inrush current could be effectively attenuated such that they can meet the related international standards and resolve the issues associated with simultaneous starting of multiple inductive loads. By employing this system, power cost usually implemented by the estimation of peak power consumption can be reduced and the power quality of a power distribution system connected to the inductive load network can be stabilized efficiently.

• Smart Structures and Systems
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• v.26 no.5
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• pp.545-558
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• 2020

A design method of a Multiple Tuned Mass Damper (MTMD) system is presented for wind induced vibration control of a cable-supported roof structure. Modal contribution analysis is carried out to determine the dominating modes of the structure for the MTMD design. Two MTMD systems are developed for two most dominating modes. Each MTMD system is composed of multiple TMDs with small masses spread at multiple locations with large responses in the corresponding mode. Frequencies of TMDs are distributed uniformly within a range around the dominating frequencies of the roof structure to enhance the robustness of the MTMD system against uncertainties of structural frequencies. Parameter optimizations are carried out by minimizing objective functions regarding the structural responses, TMD strokes, robustness and mass cost. Two optimization approaches are used: Single Objective Approach (SOA) using Sequential Quadratic Programming (SQP) with multi-start method and Multi-Objective Approach (MOA) using Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The computation efficiency of the MOA is found to be superior to the SOA with consistent optimization results. A Pareto optimal front is obtained regarding the control performance and the total weight of the TMDs, from which several specific design options are proposed. The final design may be selected based on the Pareto optimal front and other engineering factors.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2004.05a
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• pp.197-200
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• 2004

Compared to conventional flame combustion, catalytic combustion had the advantage of oxidation of V.O.C. gas which was high voluminous, low caloric mixture flow. However, the temperature of mixture gas should be over the one of catalytic reaction start and the control of reaction on the catalytic surface tends to be vulnerable. To overcome these obstacles, composition of both catalytic combustor and heat exchanger was devised and named the sequential catalytic combustion system. In this system, only trigger unit needed preheating process for transient starting time. Once trigger unit was ignited, the next unit w3s supplied heat to ignite from that and same process was performed to the last one sequentially. When it come to steady state, whole mixture gas was oxidated at each unit simultaneously and preheating for trigger unit was not needed any more. System of 100 kcalh/hr capacity was devised and operated successfully.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.114-123
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• 2005

A nonlinear speed control of a PMSM using a sequential parameter auto-tuning algorithm for servo equipments is presented. The nonlinear control scheme gives an undesirable output performance under the mismatch of the system parameters and load conditions. Recently, to improve the performance, an adaptive linearization scheme, a sliding mode control and an observer-based technique have been reported. Although a good performance can be obtained, the performance is not satisfactory any more under specific conditions such as a large inertia variation, a fast speed transient or an increased sampling time. The simultaneous estimation of principal parameters giving a direct influence on speed dynamics is generally not simple. To overcome this problem, a a sequential parameter auto-tuning algorithm at start-up is proposed, where dominant parameters are estimated in a prescribed regular sequence based on the method that one parameter is estimated during each interval. The proposed scheme is implemented on a PMSM using DSP TMS320C31 and the effectiveness is verified through simulations and experiments.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.249-251
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• 2008

In Factory Automation(FA) used by Programmable Logic Controller(PLC), Ladder Diagram(LD) is the most widely utilized and plays an important role in industrial control system. But recently, the study about Sequential Function Chart(SFC) is performed actively. When we program by SFC, generally, we design one routine from start to end. This method is difficult to design block control system, and we often make mistakes. In this paper, we propose the method that we design block control system and we analysis the difference of the method used this paper from conventional method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.49-55
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• 2006

In industrial control system used by Programmable Logic Controller(PLC), ladder Diagram(LD) is the must widely utilized and plays an important role in industrial control system. But recently, the study about Sequential Function Chart(SFC) is performed actively. When we program by SFC, generally, we design one routine from start to end. This method is difficult to design, and we often make mistakes. In this paper, we propose the method that we compose each sub-system after we design each sub-system and confirm his feasibility through an actual examples.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.1021-1022
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• 2006

In industrial control system used by Programmable Logic Controller(PLC), Ladder Diagram(LD) is the most widely utilized and plays an important role in industrial control system. But recently, the study about Sequential Function Chart(SFC) is performed actively. When we program by SFC, generally, we design one routine from start to end. This method is difficult to design, and we often make mistakes. In this paper, we propose the method that we compose each sub-system after we design each sub-system, and we analysis the difference of the method used this paper from conventional method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.462-466
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• 2006

In industrial control system used by Programmable Logic Controller(PLC), Ladder Diagram(LD) is the about widely utilized and plays an important role in industrial control system. But recently, the study about Sequential Function Chart(SFC) is performed actively. When we program by SFC, generally, we design one routine from start to end. This method is difficult to design, and we often make mistakes. In this paper, we propose the method that we compose each sub-system after we design each sub-system and we analysis the difference of the method used this paper from conventional method.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.224-237
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• 1995

An ECU(Electronic Control Unit) with 16 bit microcomputer has been developed. This system includes hardware and software for more precise control on fuel injection, ignition timing, and idle speed. This control system employs an air flow sensor of the hot wire type, a direct ignition system, an idle speed control system using a solenoid valve, and a crank angle sensor. Especially, the crank angle sensor provides two separate signals: One is the position signal(POS) which indicates 180 degree pulses per revolution, and the other is the reference signla(REF) that represents each cylinder individually. The conventional engine control system requires at least two engine revolutions in order to identify the cylinder number. However, the developed engine control system can recognize the cylinder number within a quarter of an engine revolution. Therfore, the developed engine control system has been able to control fuel injection and ignition timing more quickly and accurately, Furthermore, the number of misfire reduces during the cold start.