• Proceedings of the KSR Conference
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• 2005.05a
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• pp.237-244
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• 2005

The Auxiliary Inverter supply the power to Loads of Electric Locomotive. The Auxiliary Inverter have three characteristics. First, The Auxiliary Inverter is VVVF(variable voltage variable frequency) inverter. And, the output voltage is AC $0^{\sim}440V$. Second, The Auxiliary Inverter is controled all operations by CCU(Center Control Unit). Last, The Auxiliary Inverter have the SIBMON program. This program easily displays most of all status of auxiliary inverter.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.90.6-90
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• 2002

An active stick which has the variable force-feel characteristics is developed. A combined position and force control strategy is mechanized using a 2-axis built-in force sensor and LVDT. The 2-axis force sensor which measures the stick force felt by the operator is developed by using strain gages and appropriate instrumental amplifiers. A mathematical model of the active stick dynamics is derived, and compared with the experimental results. The frictional torque of the stick due to the mechanical contacts of several parts makes the experimental frequency responses to be dependent on the magnitude of excitation signal, and the precision closed loop control to be difficult. A friction observe...

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.255-257
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• 1994

The V/F slip frequency constant control methods are used for driving induction motor with load commutated current source inverter, that is. constant V/F and slip frequency driving is used to load commutate the inverter below the critical frequency, while constant voltage and variable frequency and slip frequency driving are used in above the critical region. In order to applicate the load commutated current source inverter to the general use, speed control range of induction noter is selected to two times at rated frequency. Therefore, economical application is possible because of the maximum reduction of the condenser of the inverter output port. The use of the proposed force commutated circuit improves the false operation of force commutated circuit and inverter commutation failure which are produced by the influence of the lower-order harmonics of the conventional load commutated current source inverter at starting.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.689-691
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• 1992

In this study, slip frequency control for a single-sided linear induction motor(SLIM) is discussed. We adopted variable slip frequency pattern in stead of constant slip frequency pattern under V/f constant mode, which is effective in improving driving efficiency of SLIM. And the dynamic characteristics are analyzed by using equivalent circuit during the accelerating time.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.1
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• pp.30-35
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• 1988

An electrical power generation system driven by main engine shaft, briefly SG system for middle or small size fishing boat is studied experimently. In the SG system, power transmission is performed by a variable displacement hydraulic pump driven by the main engine and a constant displacement hydraulic motor. It was verified that the SG system enabled the generation of electrical power with constant frequency regardless main engine speed. In the SG system, setting reference frequency, sensing generator output frequency and setting controller parameters are performed by performed by programming in a microcomputer, so a countermeasure for physical situations of control object is very easy. Futhermore, the SG system has following features; low initial installation cost, wide freedom of installation in engine room, advantage of application in existing ships, especially fishing boat with hydraulic fishing equipments.

• Smart Structures and Systems
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• v.13 no.4
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• pp.711-730
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• 2014

In this paper the system dynamic influences in actuators with variable stiffness as contemporary used in robotics for safety and efficiency reasons are investigated. Therefore, different configurations of serial and parallel elasticities are modeled by dynamic equations and linearized transfer functions. The latter ones are used to identify the characteristic behavior of the different systems and to study the effect of the different elasticities. As such actuation concepts are often used to reach energy-efficient operation, a power consumption analysis of the configurations is performed. From the comparison of this with the system dynamics, strategies to select and control stiffness are derived. Those are based on matching the natural frequencies or antiresonance modes of the actuation system to the frequency of the trajectory. Results show that exclusive serial and parallel elasticity can minimize power consumption when tuning the system to the natural frequencies. Antiresonance modes are an additional possibility for stiffness control in the series elastic setup. Configurations combining both types of elasticities do not provide further advantages regarding power reduction but an input parallel elasticity might enable for more versatile stiffness selection. Yet, design and control effort increase in such solutions. Topologies incorporating output parallel elasticity showed not to be beneficial in the chosen example but might do so in specific applications.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.472-475
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• 2008

A DC distributed power system(DPS) has many loads with varied functions. In particular, there may be large pulsed toads with short duty ratio, which can affect the normal operation of other loads. In this paper, a bi-directional converts with inductive storage is used as a DC bus conditioner to damp voltage transients on the bus. In addition, the constant frequency hysteresis control technique for a DC bus conditioner is presented. A simple and fast prediction of the hysteresis band-width is implemented by the phase-lock loop control, keeping constant switching frequency. This technique offers the excellent dynamic response in load or parameter variation. The control performance is illustrated by simulated results with the SABER package. The proposed hysteresis control results in the shortest and the smallest excursions.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.9
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• pp.179-185
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• 2002

Solid state deformation of PZT is effective for the micron scale displacement. Inch-worm gets large linear displacement by incrementally summing displacements of PZT actuators. Dynamic stiffness of inch-worm is generally low compared to its driving condition due to the small size and light weight of inch-worm. Mechanical vibration induced by low stiffness may degenerate the motion accuracy of the inch-worm. In this paper, dynamic characteristics of the inch-worm are modeled by using the frequency domain curve fitting based on the experimental frequency response function. SMC (sliding mode control) is examined for motion control of the inch-worm. Simulation and experimental results show that the inch-worm with SMC scheme is feasible for the precise displacement device.

• Journal of Power Electronics
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• v.16 no.3
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• pp.994-1003
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• 2016

Two major obstacles in the utilization of electrical vehicles are their price and range. The collaboration of direct torque control (DTC) with induction motor (IM) is preferred for its low cost, easy implementation, and parameter independency. However, in terms of edges, the method has drawbacks, such as variable switching frequency and undesired current harmonic distortion. These drawbacks result in acoustic noise, reduced efficiency, and electromagnetic interference. A feed-forward approach for stator-flux-oriented DTC with space vector pulse-width modulation is presented in in this paper. The outcome of the proposed method is low current harmonic distortion with fixed switching frequency while preserving the torque performance and simple application feature of basic DTC. The method is applicable to existing and forthcoming IM drive systems via software adaptation. The validity of the proposed method is confirmed by simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.65-67
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• 2001

PLC (Power Line Communication) is the communication method using the existing power line installed in houses and offices to convert and transmit high frequency communication signal from tens of KHz to tens of MHz, and receive the filtered signal using high frequency filter. The advantage of PLC is that PLC uses the existing power line installed in houses and offices so it does not require separate power line. Easy and convenient access using electric outlets is another advantage of PLC. However, PLC has some disadvantages such as limited transmission power, high load interference and noise, variable signal attenuation, characteristic of impedance selective possibility of frequency property. This study designed the boiler temperature control system by unit using the modem designed on the basis of technology used for PLC modem, and designed remote control system using internet. After conducting experiments with those two systems, it was possible to control stably. By commercializing this product, we can avoid unnecessary heating of separate temperature control unit, and save the cost according1y, and it is possible to control on a remote site using internet in a more convenient way.