• Journal of Institute of Control, Robotics and Systems
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• v.22 no.9
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• pp.733-737
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• 2016

In this paper, we propose a mechanism that can compensate for gravity in a robot manipulator. Industry robots generate torque due to carrying heavy weight. For this reason, the robots need high specification motors, which increases the prices of the robots and their production costs. In order to resolve these problems, a mechanism for gravity compensation has been developed using a spring and wire system. But this system has problems related to wire stretching. A winding mechanism is therefore used to supplement this drawback of the wire. The robot used was developed by the 1-DOF system. Analysis was performed for the performance of the mechanism. Experiments were conducted to compare simulation results and experimental results.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.531-533
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• 1996

The most common method of the single phase induction motor(SPIM) is to install a starting condenser and a centrifugal switch in series with the auxiliary winding. Even though this capacitor start method is embodied simply, it is feasible because of motor failure from malfunction of the centrifugal switch and the starting condenser. Moreover, it is hard to improve the performance characteristics of the SPIM. In this paper, the voltage and phase angle sequence, control strategy of the auxiliary winding of the SFIM is employed to eliminate the centrifugal switch and the starting condenser. The proposed control system is superior to a conventional system in the starting performance of SPIM. Finally, the improved starting characteristics of the SPIM is obtained with this strategy through simulation and experimental results.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.76-79
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• 1996

The most common for starting a single phase induction motor is to install a starting condenser and a centrifugal switch in series with the auxiliary winding. Though this method is simple, life of single phase induction motor is short because of malfunction of a starting condenser and a centrifugal switch and efficiency improvement has limitation. In this paper, the starting characteristics of SPIM is improved by sequence voltage control strategy of auxiliary winding in removing a starting condenser and a centrifugal switch. Finally, the excellent starting performance of SPIM is shown through simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.180-181
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• 2007

In this paper, SFCL using two magnetically coupled coils was modeled and simulated by PSCAD/EMTDC. The simulation was shown that fault current could be adjusted with the inductance ratio and the winding direction of two coils. The limited fault current in case of the additive polarity winding was lower than that of the subtractive polarity. The analysis results were compared with the calculated ones, and both the results agreed.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.907-910
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• 1992

This paper deals with the mesurement and the analysis by means of EMTP simulation for the fast-rising switching surges. The fast-rising surges having up to 180ns of front time and 3.42 p.u of peak value were measured at the 154KV substations. The fast-rising surges are expected to cause electric breakdown because the penetrating surges to the transformers result in the higher stress in the winding end than the average stress along the winding.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.5
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• pp.884-891
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• 2007

Comparing with the conventional transformer without the air gap, a contact-less transformer with the large air-gap (4.8cm) between the long primary winding and the secondary winding has the increased leakage inductance and the reduced magnetizing inductance. By the increased leakage inductance and the reduced magnetizing inductance on the primary of the contact-less transformer, a good deal of the primary current circulates through magnetizing inductance, which results in a massive loss and the high voltage gain characteristics for load variations in contact-less power supply (CPS). To consider these characteristics, in this paper, the efficiency characteristics of the contact-less power supply using a series resonant converter is presented, described and verified through theoretical analysis, computer simulation and experimental test of 2.5kW prototype.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1812-1820
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• 2017

This paper analyzes a symmetric active cell balancer for a battery management system. The considered cell balancer uses a forward converter in which the circuit structure is symmetric. This cell-balancing method uses fewer switches and is simpler than the previously proposed active cell-balancing circuits. Active power switches of this cell-balancing circuit operate simultaneously with the same pulse width modulation signals. Therefore, this cell-balancing circuit requires less time to be balanced than a previous bidirectional-forward-converter-based cell balancer. This paper analyzes the operational principles and modes of this cell balancer with computer-based circuit simulation results as well as experimental results in which each unbalanced cell is equalized with this cell balancer. The maximum power transfer efficiency of the investigated cell balancer was 87.5% from the experimental results. In addition to the experimental and analytical results, this paper presents the performance of this symmetric active cell-balancing method.

• Proceedings of the KIEE Conference
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• 2000.07e
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• pp.122-128
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• 2000

The SRM is a simple and robust machine which is finding applications over a wide power and speed range. To properly evaluate the motor performance, a reliable model design is required. This paper explains the various excitation mode and winding configuration to analyze the torque performance of SRM. A number of different idealized current excitation patterns are introduced, using unipolar, bipolar & square excitation, and the output torques produced by the various winding configurations are compared. The electromagnetic torque of the SRM was calculated from the rate of change of co-energy with respect to angular displacement. The simulation result shows that 3-phase square excitation mode models have revealed higher torque performance.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.794-799
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• 2005

In this paper, the inductive power collector using electromagnetic induction for the PRT(Personal Rapid Transit) system is suggested and some ideas for power collector design to improve the power transfer performance are presented. The proposed the inductive power collector is used for the PRT system, which has a large air-gap and demands a large electrical power capability. But, low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, double layer construction of secondary winding. which was divided in half to increase both output current and output voltage was suggested. Also, model of power collector and parallel winding structure are presented, in addition, the performance of inductive power collector to alignment condition between the primary power line and the inductive power transformer was verified by computer simulation of 2kW model.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.284-286
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• 1995

The most common for starting a single phase induction motor is to install a starting condenser and a centrifugal switch in series with the auxiliary winding. Though this method is simple, life of single phase induction motor is short because of malfunction of a starting condenser and a centrifugal switch and efficiency improvement has limitation. In this paper, the starting characteristics of SPIM is improved by voltage and phase control strategy of auxiliary winding in removing a starting condenser and a centrifugal switch. Finally, the excellent starting performance of SPIM is shown through simulation and experimental results.