• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.752-755
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• 2000

This paper describes a new algorithm for active power filters which can be control source current symmetrically under unbalanced condition in power system. Positive sequency voltage is detected by symmetrical coordinate method and compensating reference current of active power filters is calculated using by accurate phase angle information of positive sequency voltage. The basic principle of the proposed method is described in detail and the conventional and proposed phase detecting methods are compared and discussed through the simulation results.

• 전기학회논문지
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• 제64권2호
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• pp.254-259
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• 2015

On January 30, 2012 an auxiliary component of Byron Unit 2 was tripped on bus under voltage. The cause of the event was the failure of the C-phase insulator track for the Unit 2 station auxiliary transformer(SAT) revenue metering transformer. In addition to this event, other events have occurred at other plants resulting in an open-phase condition.[1] Therefore, Nuclear Regulatory Commission(NRC) has requested that not only nuclear power plant(NPP) operating company but also its Design Certification(DC) applicant have to prepare open-phase detecting system in their operating plants and design document. In this paper, various open-phase conditions are simulated in NPP using Electromagnetic Transient Program(EMTP) and Atpdraw, and open-phase condition detecting system is proposed for Main Transformer(MT), Unit Auxiliary Transformer(UAT) and SAT connected power line in NPP.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.494-497
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• 2005

In this paper, harmonic detecting methods for the active power application are investigated. They are RDFT, Kalman Filter, Adaptive predictive filter, Instantaneous reactive power detecting method, Improved adaptive filter detecting method. The 5 harmonic detecting methods are simulated and their characteristics for the active filter application are compared using simulation results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.122-125
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• 1999

The AC-to-DC single-phase PWM rectifier for traction applications using high power semiconductor, IGCT is made and tested. Parallel operation of two PWM converter is adopted for increasing capacity of converters. For reducing harmonics, the harmonic content is eliminated by the phase shift between two converters switching phase. The output voltage control is achieved by interns calculation without detecting the input current. The part of PLL used for controlling power factor is simply implemented by software.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.615-619
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• 1998

Active power filter is a kind of device used for compensating instantaneous reactive and harmonic current in three-phase circuits. An essential technology that determines the behavior of an active power filter is the method of detecting the distorted current. Using three-dimensional space vectors, this paper describes a simple method for detecting the distorted current without any coordinate transformation. The effectiveness of the novel method is verified by the theoretical analysis and simulation.

• Journal of Power Electronics
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• 제9권3호
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• pp.365-376
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• 2009

In this paper, the implementation of a three-phase shunt active power filter is presented. The filter is essentially three independent single-phase current-controlled voltage source inverters (CC-VSI) with a common DC bus. The CC- VSI is operated to directly control the AC grid current to be sinusoidal and in phase with the grid voltage without detecting the load currents. The APF consists of a current control loop, which shapes the grid currents to be sinusoidal and a voltage control loop, which regulates the active power balance of the system. The experimental results indicate that the active filter is able to handle predominantly the harmonics, as well as the unbalance and reactive power, so that the grid currents are sinusoidal, in phase with the grid voltages and symmetrical.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.291-292
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• 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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.91-93
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• 1994

Recently, for improving the power supply reliability and for rationslizing maintenance, new maintenance and monitoring systems are stornagly desired for use in the field of electric power transmission. In this paper, we describes the optical fault detecting method of underground power transmission lines using bareearth doped YIG Faraday sensors which are very light, small size and fast response. As regarding, we use the zero phase current detecting algorithm at insulated joints.

• 전력전자학회논문지
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• 제11권4호
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• pp.307-312
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• 2006

본 논문에서는 직류링크전류를 기반으로 SRM의 상전류를 추정하였고 이를 이용한 SRM 에 대한 속도제어법을 제안하였다. 또한 직류링크전류검출회로를 제안하여 전류검출분해능을 높일 수 있었으며 오프셋에 의한 영향을 최소화시킬 수 있는 장점을 가지고 있다. 상전류 정보를 이용한 SRM 구동방식과 직류링크전류정보를 이용한 SRM 구동방식을 실제실험을 통하여 비교함으로서 본 논문에서 제안한 상전류 추정알고리즘과 이에 관련된 직류링크전류 검출회로에 대한 유효성이 검증되었고 직류링크전류를 이용한 SRM 속도제어시스템은 속도응답이 3 상 전류정보를 이용한 시스템만큼 빠른 응답특성이 있음을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.139-141
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• 2000

High voltage direct current(HVDC) transmission system uses the phase controlled rectifier triggered by means of IPC(individual phase control) or EPC(equidistant pulse control). Most HVDC system has adopted EPC method that can solve the harmonic instability problem of IPC method in weak power system. But EPC has inherent indirect synchronizing problem requiring the closed loop control. This paper presents the new gate pulse generating method for 12-pulse HVDC converter, which combines IPC with EPC. Simulation and test results are presented. The basic concept is that it generates the gating pulse for 12-pulse converter by synthesizing the internal phase reference using the frequency and phase information of a sin91e phase voltage. To ensure the reliability of the external phase input, Potential transformer that detects the phase voltage has redundancy. Using fault detecting algorithm the healthy input is always guaranteed. And the frequency compensation function was reinforced.