• 전력전자학회논문지
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• 제13권6호
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• pp.476-486
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• 2008

매트릭스 컨버터에서 입력필터의 최적설계는 대단히 중요하다. 그러나 입력필터에 포함된 인덕턴스와 커패시턴스 성분으로 인해 입력 역률이 저하되고 최적 필터 설계에도 불구하고 출력 주파수와 부하에 따라 역률이 바뀌게 되므로 운전조건이 변하면 매트릭스 컨버터의 장점 가운데 하나인 높은 역률을 유지하는 것이 힘들게 된다. 본 논문에서는 매트릭스 컨버터에서 입력필터를 사용할 경우 부하나 출력 주파수가 변동하더라도 입력 역률을 거의 1로 유지할 수 있는 새로운 형태의 공간벡터변조기법을 제안하고 이를 구현할 수 있는 방법을 제시했다.

• 전력전자학회논문지
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• 제10권6호
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• pp.550-559
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• 2005

매트릭스 컨버터는 VS떼 비하여 장수명, 입력역률 직접제어 및 에너지 회생 등의 장점을 갖고 있으나, 제어의 복잡성, ride-through 대책 및 낮은 전압이용률 등은 상용화를 위해 해결해야 할 난제이다. 본 논문에서는 SVM를 적용한 매트릭스 컨버터의 설계 및 구현방법을 제안한다. 입력 고조파를 저감시키기 위한 입력필터와 입출력의 과전압 방지와 free-wheeling을 위한 클램프 회로의 설계기법을 제시하고, 고속 DSP와 CPLD를 사용하여 공간벡터 제어 및 4 단계 전류(commutation) 제어를 구현하며, 매트릭스 컨버터의 양방향 스위치 구동을 위한 전용의 전원회로를 설계하여, 최적 구조의 전력회로를 제안한다. 그리고 구현된 매트릭스 컨버터를 유도전동기에 적용하여 성공적인 운전 결과를 얻을 수 있었다.

• Journal of Power Electronics
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• 제3권4호
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• pp.239-248
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• 2003

This paper presents a novel prototype of three-phase voltage source type zero voltage soft-switching inverter with the auxiliary resonant snubbers suitable for high-power applications with IGBT power module packages in order to reduce their switching power losses as well as electromagnetic conductive and radiative noises. A proposed single inductor-assisted resonant AC link snubber circuit topology as one of some auxiliary resonant commutation snubbers developed previously to achieve the zero voltage soft-switching (ZVS) for the three-phase voltage source type sinewave PWM inverter operating under the instantaneous space voltage vector modulation is originally demonstrated as compared with the other types of resonant AC link snubber circuit topologies. In addition to this, its operation principle and unique features are described in this paper. Furthermore, the practical basic operating performances of the new conceptual instantaneous space voltage vector modulation resonant AC link snubber-assisted three-phase voltage source type soft-switching PWM inverter using IGBT power module packages are evaluated and discussed on the basis of switching voltage and current waveforms, output line to line voltage quality, power loss analysis, actual power conversion efficiency and electromagnetic conductive and radiative noises from an experimental point of view, comparing with those of conventional three-phase voltage source hard-switching PWM inverter using IGBT power modules.

• Advances in Computational Design
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• 제8권3호
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• pp.237-253
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• 2023

Torque ripple content and variable switching frequency operation of conventional direct torque control (DTC) are reduced by the integration of space vector modulation (SVM) into DTC. Integration of space vector modulation to conventional direct torque control known as SVM-DTC. It had been more frequently used method in renewable energy and machine drive systems. In this paper, SVM-DTC is used to control the rotor side converter (RSC) of a wind driven doubly-fed induction generator (DFIG) because of its advantages such as reduction of torque ripples and constant switching frequency operation. However, flux and torque ripples are still dominant due to distorted current waveforms at different operations of the wind turbine. Therefore, to smoothen the torque profile a Neural Network Controller (NNC) based SVM-DTC has been proposed by replacing the PI controller in the speed control loop of the wind turbine controller. Also, stability analysis and simulation study of DFIG using process reaction curve method (RRCM) are presented. Validation of simulation study in MATLAB/SIMULINK environment of proposed wind driven DFIG system has been performed by laboratory developed prototype model. The proposed NNC based SVM-DTC yields superior torque response and ripple reduction compared to other methods.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.670-674
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• 2016

The control performance of hybrid PWM inverter using a phase current measurement is presented in this paper. The hybrid PWM technique consists of space vector pulse width modulation (SVPWM) and six-step voltage control operation. The SVPWM is performed to reduce the harmonic components in the low speed region, and the six-step modulation is applied to increase the maximum speed of the IPMSM in the high speed region. Therefore, it is possible to obtain a great performance in both the low speed range and high speed range. However, the six-step modulation cannot be completely implemented, since the inverter that includes the lag-shunt sensing method has an immeasurable current region. In this paper, a quasi-six-step modulation using a modified voltage vector is proposed. The validity and usefulness of the proposed PWM technique is verified by MATLAB/Simulink and experimental results.

• Journal of Power Electronics
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• 제17권6호
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• pp.1500-1511
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• 2017

The purpose of this paper is to study a high-performance control scheme for neutral-point-clamping three-level (NPC-3L) inverter fed dual three-phase permanent magnet synchronous motor (PMSM) drives by considering some asymmetric factors such as the non-identical parameters in phase windings. To implement this, the system model is analyzed for dual three-phase PMSM drives with asymmetric factors based on the vector space decomposition (VSD) principle. Based on the equivalent circuits, PI controllers with feedforward compensation are used in the d-q subspace for regulating torque, where the cut-off frequency of the PI controllers are set at the twice the fundamental frequency for compensating both the additional DC component and the second order component caused by asymmetry. Meanwhile, proportional resonant (PR) controllers are proposed in the x-y subspace for suppressing the possible unbalanced currents in the phase windings. A dual three-phase space vector modulation (DT-SVM) is designed for the drive, and the balancing factor is designed based on the numerical fitting surface for balancing the DC link capacitor voltages. Experimental results are given to demonstrate the validity of the theoretical analysis and the proposed control scheme.

• Journal of Power Electronics
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• 제12권3호
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• pp.448-457
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• 2012

This paper proposes a carrier-based pulse width modulation (PWM) method to control an indirect matrix converter (IMC) by analyzing the relationship between the space vector PWM (SVPWM) and the carrier-based PWM. The complexity of the SVPWM method for an IMC can be reduced by using an equivalent carrier-based PWM method. The advantage of the proposed algorithm is its ability use only one symmetrical triangular carrier signal to generate the gate signals for all of the power switches in both the rectifier and inverter stages as compared to the conventional method where the carrier signal used in the rectifier stage is different from that of the inverter stage. In addition, by using a suitable offset voltage component in the modulation signals, the output voltage magnitude reaches 0.866 of the input voltage magnitude. Simulation and experimental results are provided in order to validate the proposed method.

• Journal of Power Electronics
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• 제16권1호
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• pp.388-397
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• 2016

An error-compensated pulse width modulator (ECPWM) is proposed to improve the baseband harmonic performance and the switching loss of voltage source inverters (VSIs). Selecting between harmonic distortion and switching loss is a design tradeoff in the conventional space vector pulse width modulation. In this work, an accumulated difference in produced and desired phase voltages is considered to adjust the reference signal. This mechanism can compensate for the voltage error in the previous carrier period. With error compensation every half-carrier period, the proposed ECPWM allows one-half reduction in carrier frequency without scarifying baseband harmonic distortion. The proposed modulator is applied to a three-phase VSI with R-L load and a motor-speed-control system for experiments. The measured efficiency and operating temperature of switches confirm the effectiveness of the proposed scheme.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.739-741
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• 1993

This paper deals with the Improvement of inverter output waveform with space vector modulation using the DSP-chip. The proposed scheme can be considered as a alternative of the conventional, subharmonic method. This scheme features a maximum output voltage that is 15% greater. The number of switchings is also 30% less than the one obtained by subharmonic modulation method(SHM) A performance function(PF) which is the time integral function of the inverter output voltage is introduced in this paper. An optimal PWM pattern is obtained by minimizing the distortion factor of performance function. The experiment was carried out with an TMS320C25.

• Journal of Power Electronics
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• 제19권4호
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• pp.944-955
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• 2019

In this paper, the three-level T-type neutral-point-clamped indirect matrix converter topology and the relative space vector modulation methods are introduced to improve the voltage transfer ratio and output voltage performance. The presented converter topology is based on combinations of cascaded-rectifier and three-level T-type neutral-point-clamp inverter. It can overcome the limitation of voltage transfer ratio of the conventional matrix converter and the high voltage rating of power switches of conventional matrix converter. Two SVPWM strategies for proposed converter are described in this paper to achieve the advantages features such as: sinusoidal input/output currents and three-level output voltage waveforms. Results from Psim 9.0 software simulation are provided to confirm the theoretical analysis. Hence, a laboratory prototype was implemented, and the experimental results are shown to validate the simulation results and to verify the effectiveness of the proposed topology and modulation strategies.