• Proceedings of the KIEE Conference
• /
• 1994.07a
• /
• pp.334-336
• /
• 1994

The conventional APF(Active Power Filter) system performs only function which is compensated for source harmonic by injecting harmonic compensation current as well as reactive power component by PWM. This paper presents a new APF which provides the combined functions of VC(Voltage Compensator) and conventional APF, because the structure of APF is similar to stand- alone UPS in parallel type. Single-chip microprocessor plays an important role in controlling each function. Simulation obtained from ACSL are shown to verify multi-functions of new APP.

• Proceedings of the KIEE Conference
• /
• 1994.07a
• /
• pp.337-341
• /
• 1994

This paper describes an effort to develop a simulator of Active Power Filter (APF) by three dimentional(3-D) space current co-ordinate. System current is represented by 3-D vector composed of three current components - active, reactive and distorted. %THD (%Total Harmonics Distortion) can be converted to height-angle of system current vector and power factor can be defined on 3-D space current co-ordinate without loss of generality. Current of APF and power system can be analyzed by 3-D visualization of current vector trajectory. So, the computer simulation results show that the proposed method by 3-D space current co-ordinate make up for disadvantages of performance evaluation on time / frequency domain.

• Proceedings of the KIEE Conference
• /
• 2004.10a
• /
• pp.224-226
• /
• 2004

Digital Kalman filter is presented as a powerful approach to obtain the reference estimation of the control current for shunt active power filter. This algorithm provides the best estimate of the fundamental and harmonic frequency components from the sampled values of the line current or voltage. By adopting of the digital Kalman filtering algorithm, the structure of the control algorithm eliminates the need of a Phase locked loop(PLL) for the synchronization of the reference signal used in the compensation and it not sensitive to the distortion of the line voltage. The effectiveness of the algorithm is confirmed by the computer simulations.

• Proceedings of the KIEE Conference
• /
• 2003.04a
• /
• pp.292-295
• /
• 2003

Conventional methods in time / frequency domain for evaluating the compensation performance of active power filters are not provided easy solutions. So, the authors have previously proposed 3-D current coordinates which is composed into active component, fundamental reactive component and distorted component of nonlinear loads current. This method has excellent performance, but can not evaluate the characteristics of nonlinear load current whether it is inductive or capacitive. Therefore, To overcome problems mentioned previously, this paper deals with the simple Average power theory and the expanded 3-D current coordinates for evaluating the compensation performance of active power filters. To confirm the validity, active power filters simulator is developed using C-language. From the simulation, results are discuss their utility.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.1480-1485
• /
• 2004

In this paper, a real-time digital kalman filtering algorithm is used to obtain the reference estimation of the control current for shunt active power filter. This algorithm provides the best estimate of the fundamental and harmonic frequency components from the sampled values of the line current or voltage waveform. By adopting of the digital Kalman filtering algorithm, the structure of the control algorithm eliminates the need of a Phase locked loop(PLL) for the synchronization of the reference signal used in the compensation and it not sensitive to the distortion of the line voltage. The effectiveness of the algorithm is confirmed by the computer simulations.

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

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.12
• /
• pp.2161-2166
• /
• 2008

This paper deals with a Z-source active power filter(Z-AFU) for mitigation voltage THD(total harmonic distortion) due to voltage harmonic propagation(amplification) in 6.6kv power distribution system. Bus voltage harmonic signal is detected by 60Hz butterworth BPF(band pass filter). As an ESS(energy storage system) of the proposed system, PEM fuel cells(Ballard NEXA, 1.2kw) is employed. Test results based on PSIM(power electronics simulation tool) validate the proposed approach.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.504-506
• /
• 2005

This paper proposes a new neutral current reduction method using PQR instantaneous power theory on the active power filter, unbalanced nonlinear load condition in three-phase four-wire systems. For reduction of neutral line current, the single phase active power filter is used and its performance is same with the three-phase four-wire active power filter. For fully-digital implementation, ramp comparison PWM method was adopted. Simulation results verify good performance of the proposed current control strategy on the shunt APFs.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.463-465
• /
• 2005

This paper proposes a regeneration inverter system, which can regenerate the excessive power form the DC bus line to the AC source for traction systems. The proposed regeneration inverter system for DC traction can reduce harmonics which is a characteristic of the AC current source. The simulation was composed as a prototype model[3.7kW]. Finally, it is shown that the inverter can successfully operate in regeneration mode.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.498-500
• /
• 2005

This paper presents a unified control scheme for series-type active power filters combined with shunt passive filters for the source voltage unbalance compensation and the power factor correction simultaneously. The power factor correction is achieved by controlling the amplitude of reactive power current in a series filter as zero in a synchronously rotating reference frame. The proposed algorithm successfully compensates the source voltage unbalance and the power factor. The validity of the proposed scheme has been verified by simulation for a 3-kVA hybrid active power filter system.