• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.349-351
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• 1999

This paper presents a new control algorithm for series active power filters that are applied to 3-phase 3-wire and 3-phase 4-wire systems with capacitive loads. It is difficult to reduce harmonic currents in neutral lines of the 3-phase 4-wire systems using conventional series active power filter control methods. 3-phase 4-wire series active power filter systems using the proposed method in this study lower neutral line harmonics. Simulation was carried out to verify the algorithm.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.15-21
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• 1998

Mostly a ride comfort and handling performance of vehicle is influenced by dynamic behavior control of vehicle. We are focusing on development of a semi-intelligent suspension system with continuously variable damper(HS-SH type). only using absolute velocity of sprung mass without using the relative velocity besides having lower system prices and a little energy requirement. In this paper, the system is realized in consideration to control strategy (sky-hook control, hybrid filter, etc.) and has been proved to have improvement of behavior control of vehicle by quarter car and Vehicle test, respectively.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.9
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• pp.361-367
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• 1985

A new injection method is proposed for active power filters to eliminate AC harmonics in ac input current of nonlinear loads such as rectifiers. By injecting the PWM current determined by the proposed injection method, all the harmonics up to order nn can be eliminated to exactly zero. This PWM injection current can be generated by sampling total harmonic wave at the rate of M and the sampled values are converted into the proposed PWM wave with N pulse-width variables and adjustable current magnitude Im. These variables are deetermined by solving a set of N nonlinear harmonic equations and the harmonic-elimination characteristics of the new injection are investigated through digital computer sinmulation. Also by comparing between the simulated results and the ones synthesized by data stored in EPROM, the possibility of the suggested injection method can be shown.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.3
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• pp.130-140
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• 2001

This paper presents the performance of a parallel active power filter(PT) system in unbalanced load condition. The unbalanced load leads to negative sequence of current, and makes 120Hz ripple in the DC-link voltage forcing large capacitance and increases the rating of APF. thus, the separation of negative sequence is performed in synchronous reference frame and controlled to flow into supply network. The validity of the scheme is investigated through simulation and the experimental results for a prototype active power filter system rated at 10kVA.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.931-932
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• 2006

This paper proposes a control algorithm for 3-phase 4-wire series active power filter. This control algorithm compensates harmonics and neutral line currents which are generated by balanced or unbalanced nonlinear loads. The advantage of this control algorithm is direct extraction of compensation voltage references. Therefore, calculation time is shorten and the performance of series active power filter is improved. Compensation principle of the proposed control algorithm is presented in detail. Experimental results are shown to verify the effectiveness of the proposed control algorithm.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.861-862
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• 2006

본 논문에서는 차동증폭기와 대역통과 필터를 이용한 심전도측정 시스템의 구현하고 동작을 확인하였다. 구현된 하드웨어의 성능평가를 위해 동일한 입력 신호에 대한 시뮬레이션 결과와 실제 출력을 비교 하였다. 또한, 실제 동작을 확인하기 위하여 심전도 신호 중 리드 II(lead II)파형을 추출하였다. 설계된 회로는 소형화 및 경량화가 가능하기 때문에, 유비쿼터스 환경에 서 이동 중 심전도신호의 측정에 적용가능하며 능동형 게임의 감성추출에도 적용 가능할 것으로 본다.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.149-151
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• 2005

This paper deals with the novel control algorithm of single-phase hybrid active power filter for the compensation of harmonic current components in nonlinear R-L load with passive active power filters. To construct two-axes coordinate, an imaginary second phase was made by giving time delay to line current. In this proposed method, the new signal, which was the delayed through the filtering by the phase-delay property of low-pass filter, is used as the secondary phase. Because two phases have different phase, instantaneous calculation of harmonic current is possible. In this paper, a reference voltage is created by multiplying gain of filter by compensation current using the rotating reference frames that synchronizes with source-frequency, not applying to instantaneous reactive power theory which has been used with the existing fixed reference frames. This paper shows the experimental results, which provide a high accuracy and extremely fast response of single-phase hybrid active Bower filter under the operation with the proposed control method.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.1
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• pp.1-7
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• 2002

The purpose of this work is to develop High-Frequency Active Filter and super-miniaturation technology(SMD Type) of Filter which are essential for the key R/F Microwave components in the Mobile telecommunication system. The cut-off frequency of high frequency active filter for multimedia is 2.5 MHz, the gain is 0.5dB at 100 kHz, the passband ripple is 1.2 dB max at 100 kHz~2.0 kHz, GDT is 60 nsec at 100 kHz-2.0 MHz, the attenuation is 40 dB min at 3.75 MHz.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.8
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• pp.377-386
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• 2005

This paper presents the control algorithm of single-phase hybrid active power filter for the compensation of harmonic current components in nonlinear R-L load with passive active Power filters. To construct two phase system, an imaginary second phase was made. In this proposed method, the new signal which is the delayed through the filtering by the phase-delay property of low-pass filter is used as the secondary phase. Because two-phases have the different phase, the instantaneous calculation of harmonic current is possible. In this paper, a reference voltage is created by multiplying the coefficient k by the compensation current using the rotating reference frame synchronized with the source-frequency, not applying to instantaneous reactive power theory which has been used with the existing fixed reference frames In order to verify the validities of the proposed control methods, experiments are carried out with the prototypes of single-phase hybrid active power filter.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.12
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• pp.715-726
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• 1999

This paper estimates the capacity of shunt type active power filters(APF) for harmonic/reactive power compensation with a thyristor converter load. The base capacity requirement of APF is defined for idealized converter load current waveform and the effect of commutation overlap on the APF capacity is examined. The APF capacity required for reactive power compensation in addition to the harmonic elimination is estimated to give maximum achievable power factor for various operating condition of the partially-loaded thyristor converter. The method of current limit of APF is introduced, and it is shown that the APF capacity can be considerably reduced by deliberately limiting the peak current while maintaining the filtering performance to meet the level std 519 regulation.