• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.8
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• pp.451-458
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• 2000

The precise speed and position control technique for Brushless DC Motor demands accurate position and speed feedback information. Generally, resolver or absolute encoders are used as speed and positiion sensor. But they increase cost and more problem happens at low speed than high speed specially. Therefore, in this paper, optimal speed observer is proposed for decreasing size and cost of whole system. And also, we consider the error problem about the system modeling and measurement at low speed range as well as high speed. The overall system consists of two parts, a drive and a speed observer. We make use of Least square curve fitting algorithm as speed observer and can overcome low resolution by proposed observer. Also, because of using the signal of hall sensor, robust control is possible in low speed as well as high speed for the change of the parameters of the system and disturbance. To construct observer using the signal of hall sensor, we design the pulse multiplier circuit and the software of microprocessor, AT89CC2051. Finally, the performance of the proposed observer is exemplified by some simulations and experiments.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.2
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• pp.89-97
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• 2006

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. The paper is proposed maximum torque control of IPMSM drive using learning mechanism-fuzzy neural network(LM-FNN) controller and artificial neural network(ANN). The control method is applicable over the entire speed range and considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current $i_{d}$ for maximum torque operation is derived. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using LM-FNN controller and ANN controller. The hybrid combination of neural network and fuzzy control will produce a powerful representation flexibility and numerical processing capability. Also, this paper is proposed speed control of IPMSM using LM-FNN and estimation of speed using ANN controller. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The proposed control algorithm is applied to IPMSM drive system controlled LM-FNN and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the LM-FNN and ANN controller.

• Journal of the Korean Vacuum Society
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• v.22 no.2
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• pp.45-54
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• 2013

The cryopump of the pulse tube type has been developed successfully, and manufacturing of a prototype pump is finished under leading of Woosung Vacuum. The target pumping speed of the prototype pump is above 3,600 L/s for nitrogen with the intake port of 14 inches I.D (16 inches O.D). For designing optimally the pump structure including the charcoal array, thermal shield, and baffle, the pumping speed was simulated for various configurations through Monte Carlo method. Pumping performances of the protype cryopump manufactured on the basis of optimal design were conformed experimentally with a standard test system and procedures. The measured $N_2$ pumping speed of the prototype cryopump was 4,600 L/s which agreed well with simulated one and exceeded the target value.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.123-125
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• 2001

Salient pole rotor type single phase SRM(switched reluctance motor) uses the magnetic fluxes of radial and axial direction at the same time. Therefore the output power per unit volumn is very high and shaft length can be shorter than any other types of SRM with same output. Also, It can be manufactured with low cost thanks to simple structure and driving circuit. We already designed and manufactured prototype using the dynamic output equation of general rotating machine but the effect by salient pole structure was not considered. The most optimal design parameters for salient pole rotor type single phase SRM will be selected by comparing and analyzing the results from 3D FEM analysis, experimental values of the torque versus speed characteristics. and the nux linkage of prototype. Results for the former 3D FEM analysis and torque vs. speed characteristics were already obtained. Finally, we will measure the nux linkage of salient pole rotor type single phase SRM.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.5
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• pp.241-248
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• 2000

Until now, all of the port goods are transported manually by container transporter in the port. Recently there are a lot of studies about unmanned vehicle driven automatically. In terms of the vehicle automation, the control of steering and velocity on vehicle systems is very important part in container transporter. In common sense, vehicle systems have lots of nonlinear parameters so we have many difficulties in designing the optimal controller of them. In this paper, we present a design of the TDOF PID controller using a hybrid schematic algorithm to control the steering system optimally. We used the single-track model to pre-test the designed controller before appling to AGV. We also used the ES(evolutionary strategy) and SA(simulated annealing) algorithms to construct the hybrid tuning algorithm for parameters of controller. Finally, we had the computer simulation to verify that our designed controller has better performance than the other one.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.228-234
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• 2001

NTMS(Non-contact Tilted-angle Measuring System) is developed by using the principle that the magnetic field of an anisotropic magnet's inner space is uniform and it's possible to measure the strength of the magnetic field using a linear hall effect sensor. In order to implement the caliper system of the geometry PIG(Pipeline Inspection Gauge) which has high accuracy and proper output voltage of the hall sensor without additional driving module or a signal amplifier, it is necessary to consider the size of the magnet, the inner space and back-yoke and the position of pin-hole in the magnet. So the optimal design method of the caliper system is proposed through analysis of NTMS's magnetic field adopting a FEM(Finite Element Method). The experimental results show that the developed caliper system can be used for the geometry pig with good performances.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.6
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• pp.578-584
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• 2019

The occurrence of white plume in the cooling tower is phenomenon that the steam in the air through the cooling tower fan is condensed again by the cold ambient air to become saturated moist air. Accordingly, this can cause many problems like spoiling landscape around the cooling tower, odor of ambient air, falling accident by frozenness in the winter, and traffic accident, etc. This study was to install the heat exchanger in the inside of the cooling tower in order to prevent the white plume phenomenon in the cooling tower without affecting the performance of cooling tower. In addition, this study was to discharge the part of cooling water into the atmosphere through the recirculation of heat exchanger after creating dry air by heating the saturated moist air to the dew point temperature. At that time, this study was to conduct the experimental study in order to secure the optimal design data to prevent the white plume in the cooling tower because it checked the dry·moist temperature and relative humidity in the inside·outside of cooling tower on the moist air, and evaluated the performance of the heat exchanger.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.26-28
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• 2009

This paper proposes maximum torque control of IPMSM drive using adaptive teaming mechanism-fuzzy neural network (ALM-FNN) controller, model reference adaptive fuzzy tonal(MFC) and artificial neural network(ANN). This control method is applicable over the entire speed range which considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using ALM-FNN, MFC and ANN controller. The proposed control algorithm is applied to IPMSM drive system controlled ALM-FNN, MFC and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper proposes the analysis results to verify the effectiveness of the ALM-FNN, MFC and ANN controller.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.309-314
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• 2006

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. This paper proposes maximum torque control of IPMSM drive using adaptive learning fuzzy neural network and artificial neural network. This control method is applicable over the entire speed range which considered the limits of the inverter's current md voltage rated value. For each control mode, a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using adaptive teaming fuzzy neural network and artificial neural network. The hybrid combination of neural network and fuzzy control will produce a powerful representation flexibility and numerical processing capability. Also, this paper proposes speed control of IPMSM using adaptive teaming fuzzy neural network and estimation of speed using artificial neural network. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The proposed control algorithm is applied to IPMSM drive system controlled adaptive teaming fuzzy neural network and artificial neural network, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper proposes the analysis results to verify the effectiveness of the adaptive teaming fuzzy neural network and artificial neural network.

• Journal of the Korean Institute of Gas
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• v.6 no.1 s.17
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• pp.74-80
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• 2002

This study was carried out for the purpose of safety evaluation about the ventilation system (according to the structure of confined room, the position and size of vent window, the amount of blowing air, e.t.c.), which is equipped in one of KOGAS underground valve stations. Particularly, the effect of the fans placed in the upper region was focused in detail. Numerical simulation was conducted in order to predict the features of flow pattern and the diffusion of natural gas concentration. This work examined the ventilation system and resulted in proposing an optimal design of ventilation system.