• Proceedings of the KIPE Conference
• /
• 2011.11a
• /
• pp.291-292
• /
• 2011

This paper proposes an extraction method for reactor parameters in atmosphere plasma power supplies. This method is performed by detecting phase difference between inverter voltage and current, and extracting the reactance through reactive power. The validity of the proposed scheme is investigated through simulation results and experimental results.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.594-597
• /
• 2005

This paper shows that the defect detection in TFTarray panel can be improved by using newly developed software solution without adding additional hardware instruments. Some issues are reviewed in current TFT array test and new algorithm is explained for detecting more real defects without paying the penalty of reporting more false defects in TFT array test.

• 전기의세계
• /
• v.25 no.4
• /
• pp.59-62
• /
• 1976

This study on the characteristics of the leakage circuit breakers handles the rolls of each itemized parts of the mentioned apparatus and their influence in determining of the characteristic curve of leakage circuit breaker. Furthermore the differential current transforms in the mentioned apparatus for detecting the fault is handled as a heavy point.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.3
• /
• pp.447-452
• /
• 2013

In this paper, the leakage current detection and auto shut-off module for a concent has been developed. Existing leakage current detection modules are detecting resistive leakage current, using a resistive leakage current detection chip but the proposed leakage current detection module separates and detects resistive leakage current in the synthesis leakage current by only programming in a power processor MCU(MSP430). The module implemented by proposed method has early detection and auto shut-off feature at more than resistive leakage current 5mA, and has the advantage of easily adjusting resistive leakage current less or more than 5mA, because of resistive leakage current detection function being implemented by a program in MCU.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.05b
• /
• pp.47-50
• /
• 2002

The displacemant current measuring system used for detecting the dynamic behavior of monolayers at the air-water interface is described. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is placed in the water. With Maxwell-displacement-current-measuring method, the phase transitons of $Poly-{\gamma}-benzyl_{L}$ -glutamate (PBLG) and $Poly-{\gamma}-benzyl_{D}$-glutamate(PBDG) on a water surface were detected. Measured surface pressure, displacement current and dipole moment of monolayers of PBLG and PBDG on the water surface. Also, we measured that compression velocity (30, 40, 50[mm/min]) when the sample spread volume was about 370[ul]-400[ul] and displacement current that occur when differed temperature. From the result, it is known that current is generated in the range of high surface pressures as compression velocity become faster and increase of temperature.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.631-634
• /
• 2001

This paper presents a maximum power point tracking without a current sensor for a small scale photovoltaic power system. The small scale photovoltaic power systems are used in parallel, and so the cost and the reliability are strongly demanded. In the proposed inverter, the current is controlled with open loop, and then the power of photovoltaic array is calculated by the equation using the voltage of the photovoltaic array. Therefore, the system can obtain the power by detecting only the voltage of the photovoltaic array. As a result, we may obtain the performance of the MPPT with a current sensor as well as with a current sensor.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.4
• /
• pp.615-620
• /
• 2017

In this study, we have developed the resistive leakage current detecting and tripping circuit breaker based on a 32bit ARM processor. The developed leakage circuit breaker can be operated in a desired trip threshold within 0.03 seconds as specified in KS C 4613. This resistive leakage current breaker is expected to be applicable as a circuit breake for prevention of electric fires and electric shock in smart distribution panel.

• Journal of Electrical Engineering and information Science
• /
• v.2 no.4
• /
• pp.86-91
• /
• 1997

A method of detecting the three phase currents for a voltage-fed pusle width modulated(PWM) inverter is proposed, where only one current sensor is utilized on the dc-link. The proposed method has the constant sampling time by employing he modified space-vector PWM technique which generates the rearranged switching pattern to detect a phase current from ad dc-link current. Experimental results show that eh proposed scheme provides a very good detection method of three phase currents without phase current sensors. This method is very simple and has small detection errors.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.17 no.5
• /
• pp.43-50
• /
• 2003

This presents a fault detecting method for a power transformer based upon a neural network. To maintain a normal relay operating conditions, external winding faults of a power transformer and magnetic inrush have been tested under consideration of the EMTP/ATP software and internal faults of power transformer have been tested by the EMTP/BCTRAN software. The neural network has been evaluated by the proposed fault. Input variables of the neural network for the proposed model can be obtained from fundamental currents, restraining and operating currents. This algorithm uses back-propagation and the ratio of a restraining current and an operating current as relay input parameters. The ratio may enhance the fault detection since the restraining currents increase rapidly at external faults. The proposed detecting method has been applied to the practical relay systems for transformer protection. As a result, the proposed detecting method based on the neural network has been shown to have better characteristics.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.5 no.2
• /
• pp.164-170
• /
• 2010

In brushless DC motor, current flow should be controlled such that only properly selected 2 out of 3 phases carry current depending on the position of rotor. In order to detect position of rotor, hole sensor, encoder, optical position-detecting sensor, and magnetic position-detecting sensor are frequently employed. These sensors not only often cause malfunction in low and high temperature but they also have disadvantage of increasing cost and size of an motor system. To reduce the cost and size and to increase the robustness of the motor system, recently researches on sensorless motor dirve are very active. This paper proposes a novel unipolar PWM switching method that can improve the control problem caused by the difficulty of detecting zero crossing point at high revolution speed by minimizing the switching noise while increasing the lifespan of the drive system.