• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1990.10a
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• pp.68-72
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• 1990

In this paper, the technique of particul-ar harmonics elimination in three-phase PWM Inverter is discussed. And voltage control technique is derived whereby harmonics eli-mination is possible in variable voltage variable frequency three-phase I.M. The results show that experiments are in a good agreement with simulation based on the theory.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.675-679
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• 1999

A single-phase PWM current source rectifier with a neutral leg is presented and throughly analyzed in this paper. This novel topology is implemented by adding an extra leg a step-down single phase PWM space vector modulation method to reduce the dc output voltage harmonics is proposed. The PWM pattern generation need a digital system. As compared with a conventional single-phase PWM rectifier, over 20% improvement of the total harmonics distortion in the output voltage can be obtained. Different SVM techniques are analyzed for this PWM rectifier and simulation result are presented.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.291-294
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• 1998

This paper presents a new active power filter with low DC voltage for compensating reactive power and harmonics of three-phase high power/voltage harmonic producing load. It has a structure of converter connected in series with power factor correction capacitor. Appropriate size and number of filter capacitor are determined by an equation and applied to simulation of 10kvar 6-pulse SCR rectifier.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.8
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• pp.610-616
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• 1989

The line commutated inverter with GTO forced commutation is described in this paper. The presented circuit has one bypass GTO inserted in DC power side line commutated thyristor inverter. The extended commutation region with additional one GTO-commutation is clearly shown. Also, a new PWM pattern is presented to decrease the effects of harmonics for commutation. A criterion for designing the AC filter parameters to decrease harmonics of AC part is given. The simulation and experimental results clearly show that the proposed circuit can be adapted in the application of regeneration.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.151-152
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• 2015

This paper is research on design controller of grid connected 3-phase inverter. It confirms effects of high harmonics on controller and imposes repetitive controller to minimize effects on the high harmonics. The result of test in this paper is drawn by simulation tool.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.393-394
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• 2020

In this paper, an improved rotor speed estimation in DFIG wind turbine systems based on a cascaded SOGI is proposed. Due to excellent harmonics and DC offset rejection capability of the cascaded SOGI, the accurate rotor speed estimation can be achieved despite the harmonics and sensing offset in DFIG currents. The simulation results have verified the validity of proposed method.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1046-1048
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• 2002

The increase of triplen harmonics in three-phase four-wire systems leads to overloaded neutral conductor, common-mode noise problems, derating of transformers, and so on. Various compensator has been designed to prevent the problems associated with the triplen harmonics. But these can not protect distribution system effectively because the triplen harmonic source is distributed extensively and distribution system type is diverse. This paper explain the operation and installation of single phase active power filter to eliminate triplen harmonics and then it is verified by simulation.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.409-412
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• 2002

The delta modulation used for controlling the speed of an induction motor has high peak of harmonic spectrum at low speed range causing acoustic noises in the induction motor. This paper proposes to suppress the harmonics by synchronizing the reference signal with the hysteresis windows for controlling the distribution of the switching frequency. As a result we can decrease the peak of harmonic spectrum. The simulation results show that the peak spectrum of harmonics can be reduced up to 60%.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.159-162
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• 2002

The eleventh-order coupled line lowpass filter(LPF) was designed to suppress harmonics and spurious signals. The microstrip type LPF was fabricated using a high-$T_{c}$ superconductor(HTS) $YBa_{2}$$Cu_{3}$$O_{7-x}$(YBCO) thin film with the $CeO_{2}$ buffer layer which was deposited on the sapphire ($Al_{2}O_{3}$) substrate of 30 x 30 $mm^{2}$. The coupled-line type LPF was designed for 1.2 GHz of cutoff frequency with 0.01 dB of ripple level at passband. The fabricated HTS LPF shows excellent attenuation characteristics in stopband of 1.2~9.5GHz (7-attenuation poles in the stopband), and shows low insertion loss (0.2 dB) and return loss (17.1 dB) in the pass- band. These measured results match well with those obtained by the EM simulation. This clearly demonstrates that the HTS LPF can suppress harmonics and spurious signals effectively.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.161-165
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• 2003

In this paper, A new controller for power factor and harmonics compensation of a single-phase PWM converter is described. The proposed controller requires only the dc voltage sensor and the at current sensor to compensate the power factor and harmonics. Detail simulation model with EMTBC (Electro-Magnetic Transient program for DC transmission) including power circuit and controller was developed to verify the operation of proposed controller. The application feasibility of the proposed controller was verified through experimental works with a prototype. The proposed controller has a simple structure in the point of hardware implementation, and shows excellent performance in normal operation as well as in sudden load change.