• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.6
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• pp.525-537
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• 2001

In this paper a new space vector RPPWM(Random Position PWM) is proposed. In the propsed RPPWM each of three phase pulses is located randomly in each switching interval. Based on the Space vector modulation technique the duty ratio of the pulses is calculated Along with the randomization of the PWM pulses. we can obtain the effects of spread spectra of votlage, current as in the case of randomly changed switching frequency, To verify the validity of the proposed RPPWM simulation study was tried using Matlab/Simulink The main model described in Simulink block diagrams includes the space vector modulation block pulse position randomization block inverter block 3 phase induction motor block and so on By the simulation study, the harmonics of the output voltage and the current of inverter are predicted in different PWM methods- SVPWM, LLPWM proposed RPPWM.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.452-455
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• 1999

일반적인 전동기부하는 저속에서 큰 토크를 필요로 하지 않으므로, 인버터로 전동기를 구동하고자 할 때는 낮은 평균전압이 필요하다. 그러나 전력전자 소자의 제한된 스위칭 주파수, 단락 방지를 위한 데드타임 그리고 스위치나 다이오드 도통전압 등으로 인하여, 전류제어 루프 내에는 비선형성이 존재한다. 이러한 비선형성은 디지털 방식의 PWM에서 저전압을 합성할 때 현저하게 나타나는데 결과적으로 교류전동기의 저속운전을 어렵게 한다. 본 논문에서는 기존 디지털방식 PWM의 비선형성을 모델링 하고 그 비선형성을 감소시킬 수 있는 공간벡터 변조기법을 제시하였다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.253-254
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• 2006

this paper suggest a new space vector PWM modulation method with short processing time which does not need idenfication of nearest three vectors(NTV) and duty calculation for each vector. The suggested PWM method makes mean value of phase voltage to be same as reference during every modulation period by use of a triangle in small hexagon on multi-level vector space. This paper described the suggested modulation method can be successfully applied to the space vector modulation use of multi-level inverter by computer simulations and experiments.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.1
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• pp.1-10
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• 2002

In this paper the space voltage vector pulsewidth modulation(SVPWM) technique for two-phase inverter is proposed. The two-phase SVPWM technique is applicable to two-phase induction motor drives. The two-phase inverter using two-phase SVPWM technique cannot generate zero voltage vectors, but four space vectors. A reference voltage vector in the square locus is realized by adjusting four space vectors. The switching sequence "two-phase symmetrical modulation" used in two-phase SVPWM is proposed. Practical verification of theoretical predictions is presented to conform the capabilities of the new technique.technique.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.299-302
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• 1999

An analog implementation of space vector PWM is proposed in this paper. It is shown that a space vector PWM can be implemented by adding a zero sequency voltage to reference voltage of triangle comparison PWM. The proposed scheme is implemented by six diodes and, an operational amplifier circuit and, a few resistors.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.230-231
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• 2016

본 논문은 공간벡터 변조 방법에서부터 Six-step 동작까지의 새로운 과변조 방법을 제시하였다. 극전압을 푸리에 시리즈를 이용하여 분석하였고 지령 상전압에서부터 펄스 폭 변조 스위칭 신호까지의 알고리즘을 제안하였다. Matlab 시뮬레이션을 통해 검증하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.498-503
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• 2019

Electric propulsion ships are gaining widespread interest in the marine industry owing to extreme air pollution concerns. Consequently, several studies are actively being conducted for improving the power quality. Various methods have been developed that incorporate passive filters, notch filters, and active filters for reducing the harmonic content in the input current of a conventional diode front end rectifier. Among such filters, the active front end (AFE) rectifier is considered as an excellent technology. In this paper, current control for an AFE rectifier employing space vector PWM (Pulse Width Modulation) is proposed. Conventional current control methods for the AFE rectifier, hysteresis, SPWM (Sinusoidal Pulse Width Modulation), and SVPWM (Space Vector Pulse Width Modulation) were simulated by employing the PSIM software tool for analysis and comparisons. The results corroborate that SVPWM has the simplest structure and provides the best performance.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.1
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• pp.13-18
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• 1999

This paper proposes a new overmodulation stategy to give a better voltage by the full utilization of the hexagon voltage range in the space vector PWM(SVPWM) inverter. This overmodulation strategy can apply to the vector control, leading to better output torque capability in the ac motor drive system. This strategy is that in the overmodulation range, the d-axis output current is given a priority to regulate the flux well, instead the q-axis output curent is sacrificed. Therefore, the vector control even in the overmodulation PWM operation can be achieved well. For this purpose, the d-axis output voltage of a current controller to control the flux is conserved. the q-axis output voltage to control the torque is controlled to place the reference voltage vector on the hexagon boundary in case of the overmodulation. The validity of the proposed overall scheme is confirmed by simulation and experiments for a 22[kW] induction motor drive system

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.180-182
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• 2019

본 논문에서는 옵셋 전압을 이용한 3레벨 인버터의 불연속 PWM 방법을 제안한다. 스위칭 상태에 따른 3레벨 인버터의 출력전압을 벡터공간에서 도시하여 전압 변조 지수에 따른 DC 레일 및 중성단 클램핑 가능 영역을 분석한다. 이를 바탕으로, 3상 전압 지령 크기를 입력으로 받아 중성단의 클램핑 가능 여부를 판별하고 원하는 지점으로 클램핑 시켜주는 옵셋 전압 생성부를 제안한다. 제안된 방법은 공간 벡터 전압 변조 방식에 비해 간단하며, 기존 2레벨 인버터의 불연속 PWM 방식을 기반으로 하므로 구현에 용이하다. 시뮬레이션 및 실험으로 이론의 타당성 및 효과를 검증하였다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.7
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• pp.742-752
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• 1992

In this paper, a space vector concept is generalized for PWM(pulse-width modulated) inverters and PWM rectifiers with current link and voltage link respectively. Through representing three-phase variables as a space vector, we propose space vector modulations for PWM voltage and current source inverters, and PWM rectifiers with current link and voltage link. For these types, switching states of the switches are systematically analyzed from tables. It is shown in three-phase PWM rectifiers that power factor of the line current and output dc voltage can be controlled arbitrarily. The PWM rectifier with current link is also given as an example system.