• Journal of Institute of Control, Robotics and Systems
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• v.13 no.3
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• pp.192-197
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• 2007

This paper presents Hybrid PI controller of IPMSM drive using fuzzy adaptive mechanism(FAM) control. In general, PI controller in computer numerically controlled machine process fixed gain. They may perform well under some operating conditions, but not all. To increase the robustness, fixed gain PI controller, Hybrid PI controller proposes a new method based self tuning PI controller. Hybrid PI controller is developed to minimize overshoot and settling time following sudden parameter changes such as speed, load torque, inertia, rotor resistance and self inductance. The results on a speed controller of IPMSM are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.11
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• pp.84-93
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• 2009

In this paper, we propose to study the possibility of using a photovoltaic system combined with a high speed micro-turbine. This hybrid system can work as stand-alone system or grid connected system as it will be a part of a micro-grid. Initially, we propose Matlab/Simulink dynamic models of photovoltaic, micro turbine systems and supercapacitor. Then, we carry out a simulation comparison of the two systems, this is, with supercapacitor and without supercapacitor bank. We show that supercapacitor bank as short-term storage device was necessary to reduce the fast fluctuation of power in the case of sensitive loads. It is verified the simulation results of Matlab/Simulink based hybrid power system represent the effectiveness of the suggested hybrid power system.

• 한국전산유체공학회:학술대회논문집
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• 2006.05a
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• pp.275-278
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• 2006

Japan Aerospace Exploration Agency has introduced a new terascale clusterd SMP system as a main compute engine of Numerical Simulator III for aerospace science and engineering research purposes. The system is using Fujitsu PRIMEPOWER HPC2500; it has computing capability of 9.3Tflop/s peak performance and 3.6TB of user memory, with about 1,800 scalar processors for computation. In this paper, we first present the performance evaluation results for aerospace CFD applications with hybrid programming paradigm used at JAXA. Next we propose a performance prediction formula for hybrid codes based on a simple extension of AMhhal's law, and discuss about the predicted and measured performances for some typical hybrid CFD codes.

• Journal of Computational Design and Engineering
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• v.2 no.3
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• pp.137-147
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• 2015

In this study, a new methodology in predicting a system output has been investigated by applying a data mining technique and a hybrid type II fuzzy system in CNC turning operations. The purpose was to generate a supplemental control function under the dynamic machining environment, where unforeseeable changes may occur frequently. Two different types of membership functions were developed for the fuzzy logic systems and also by combining the two types, a hybrid system was generated. Genetic algorithm was used for fuzzy adaptation in the control system. Fuzzy rules are automatically modified in the process of genetic algorithm training. The computational results showed that the hybrid system with a genetic adaptation generated a far better accuracy. The hybrid fuzzy system with genetic algorithm training demonstrated more effective prediction capability and a strong potential for the implementation into existing control functions.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.312-319
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• 2012

The operation principle of an axial flux-switching hybrid excitation synchronous machine (AFHESM) is analyzed and its topology structures are proposed in this paper. After some comprehensive analysis of the operation principle to axial flux electrical machine, flux-switching electrical machine and hybrid excitation electrical machine, the operation principle of AFHESM is given. Combined with some typical topological structures of hybrid excitation electrical machine, some possible topological structures are proposed and some comprehensive comparisons are carried out. The analysis results show that the stator-separated AFHESM has some advantages such as less AM turns, less impact on the demagnetization of PM, less magnetic flux-leakage and higher efficiency compared to other topologies.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.2
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• pp.89-96
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• 2002

A new chattering free PD-sliding mode hybrid control scheme is proposed for robot manipulators. This hybrid controller is composed of a PD controller and a semi-continuous sliding mode controller. It has a good robust performance in reaching mode which does not possess invariance property of sliding mode, and has chattering free characteristics in sliding mode. Thus, the PD-sliding mode hybrid controller has a good robust performance in the whole region. It is shown that the proposed control has a good transient response and trajectory tracking performance for a 2-link SCARA robot manipulator.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.4
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• pp.399-407
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• 2011

This study analyzes the performance of hybrid power systems combining a solid oxide fuel cell (SOFC) and a gas turbine (GT). Research focus is given to the influence of the size-dependent gas turbine performance on hybrid system performance. Three hybrid systems adopting different gas turbines (kW, sub-MW, multi-MW classes) are designed. As the gas turbine power increases (i.e. as the gas turbine performance enhances), the gas turbine power portion increases and the hybrid system efficiency increases. The hybrid system shows efficiency improvement over the SOFC only system even in the case where the gas turbine net power is nearly zero. The increase of gas turbine pressure ratio contributes to the net hybrid system power output in all of the three cases, while system efficiency is almost independent on the pressure ratio.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.3
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• pp.63-76
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• 2004

This paper presents LRB-based hybrid base isolation systems employing additional active/semiactive control devices for mitigating earthquake-induced vibration of a cable-stayed 29 bridge. Hybrid base isolation systems could improve the control performance compared with the passive type-base isolation system such as LRB-installed bridge system due to multiple control devices are operating. In this paper, the additional response reduction by the two typical additional control devices, such as active type hydraulic actuators controlled by LQG algorithm and semiactive-type magnetorheological dampers controlled by clipped-optimal algorithm, have been evaluated bypreliminarily investigating the slightly modified version of the ASCE phase I benchmark cable-stayed bridge problem (i.e., the installation of LRBs to the nominal cable-stayed bridge model of the problem). It shows from the numerical simulation results that all the LRB based hybrid seismic isolation systems considered are quite effective to mitigate the structural responses. In addition, the numerical results demonstrate that the LRB based hybrid seismic isolation systems employing MR dampers have the robustness to some degree of the stiffness uncertainty of in the structure, whereas the hybrid system employing hydraulic actuators does not. Therefore, the feasibility of the hybrid base isolation systems employing semiactive additional control devices could be more appropriate in realfor full-scale civil infrastructure applications is clearly verified due to their efficacy and robustness.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1492-1502
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• 2016

• New & Renewable Energy
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• v.10 no.3
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• pp.22-30
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• 2014

The isolated self-generating electricity with diesel engine generator has been used in islands far away from main land. It costs high because of increasing oil price, and unsafe to have supplying oil and its related components by ship due to unexpectable marine conditions. Therefore there is the need for the hybrid system of renewable energy like wind or solar energy systems with oil engine generator, which can reduce oil use and extend oil supplying period. In this study, the feasibility of such hybrid system with smart micro grid on the eight islands of Jeon-nam province is surveyed to find good place for the demonstration test of the hybrid system. In each island, 3 wind turbine systems of 10 kW and photovoltaic of 20 kW are tested with already installed diesel engine. The performance and costs of the hybrid system in each island are compared in the given conditions of solar and wind energy potential. As a result of the study, Jung-ma island is recommended for the optimum place to make real field demonstration test of isolated hybrid generating and smart grid systems.