• 전력전자학회논문지
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• 제17권2호
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• pp.129-134
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• 2012

In this paper, a new simple PWM method for Vienna rectifier is proposed. The previous SVPWM method for Vienna rectifier is very complex and difficult to implement. To solve these problems, a new single-carrier comparison PWM method for voltage control of Vienna rectifier is proposed. Because of using the only single carrier, implementation of the proposed PWM is very simple. In the proposed PWM method, carrier comparison parts of the PWM block is only changed from the 2 level PWM control block. The usefulness of the proposed PWM method is verified by the simulation and experiment.

• Journal of Power Electronics
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• 제10권4호
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• pp.357-364
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• 2010

In this paper, a novel analysis of a carrier based PWM method for multilevel inverters is presented. The space vector PWM and carrier based PWM correlations in multilevel inverters are investigated in a nominal two-level switching diagram. The obtained results can be applied to design various carrier PWM techniques. In this paper, a carrier based single-state PWM technique, which reduces the switching number and optimizes the active voltage errors, is presented. This PWM technique can be advantageous if there are a large number of levels. The proposed method is mathematically formulated and demonstrated by simulations and experimental results.

• Journal of Power Electronics
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• 제5권1호
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• pp.76-82
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• 2005

A novel variant of full multi-modulation applications to diode-clamped and cascade multilevel inverter-termed single carrier multi-modulation is presented. The proposed PWM-technique is advantageous for its simple implementation. The correlation between multi-carrier and single-carrier multi-modulations is deduced. For the PWM methods, a mathematical model of voltage source inverter and general algorithm for the multi-modulating modulator are proposed. The theory is demonstrated by simulation results

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권11호
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• pp.547-552
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• 2005

This paper describes a pseudo-random carrier PW technique for the power converters. The proposed method generates a new pseudo-random carrier by randomly composing a carrier with fixed frequency and a carrier with opposition phase. To confirm the validity of the proposed method, a single-phase multi-level inverter was implemented and tested. The experimental results show that the output voltage and current harmonics spectra of an inverter have broadening effect of harmonics, as only simple composition of fixed frequency carries.

• 전력전자학회논문지
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• 제8권3호
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• pp.292-298
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• 2003

교류전동기의 가변속 운전에 사용되는 삼상 인버터에는 두개 또는 세개의 전류센서가 장착되며 이를 이용하여 삼상 교류전류를 측정한다. 전류센서의 갯수를 줄이기 위하여 개발된 것이 직류링크에 한개의 전류센서로 직류전류를 측정하고 측정된 전류 값과 스위칭 상태로부터 삼상 교류전류를 추정하는 방법이다. 전류를 정확히 측정하려면 스위칭 상태가 최소 측정시간 이상 유지되어야 하며, 이를 위한 펄스폭 조정과 이에 따른 전압 왜곡의 보상 방법이 연구되어 왔다. 그러나 기존에 발표된 방식들은 공간벡터 전압변조법에는 적합하지만 산업체에서 널리 쓰이는 펄스폭 변조 방식인 삼각파 비교법에 적용하기에는 어려운 면이 많다. 본 연구에서는 삼각파 비교법에 적합한 전류 측정 방식과 전압왜곡 보상 방식을 제안하고 이의 타당성을 실험을 통하여 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.625-629
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• 2004

This paper presents a systematical approach to study carrier based PWM techniques (CPWM) in diode-clamped and cascade multilevel inverters by using a proposed named multi-modulating pattern method. This method is based on the vector correlation between CPWM and the space vector PWM (SVPWM) and applicable to both multilevel inverter topologies. A CPWM technique can be described in a general mathematical equation, and obtain the same outputs similarly as of the corresponding SVPWM. Control of the fundamental voltage, vector redundancies and phase redundancies in multilevel inverter can be formulated separately in the CPWM equation. The deduced CPWM can obtain the full vector redundancy control, and fully utilize phase redundancy in a cascade inverter In this continued part, it will be deduced correlation between CPWM equations in multi-carrier system and single carrier system, present the mathematical model of voltage source inverter related to the common mode voltage and propose a general algorithm for multi-modulating modulator. The obtained theory will be demonstrated by simulation results.

• Journal of Power Electronics
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• 제19권1호
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• pp.134-145
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• 2019

A single-phase step-up five-level inverter topology with a new phase-shifted pulse width modulation (PS-PWM) strategy is proposed in this paper. When compared with conventional single-phase five-level inverter topologies, the proposed topology can realize multilevel inversion with a double step-up ratio, a reduced number of switching devices and self-balanced capacitor voltages. When compared with the conventional PS-PWM strategy, the new PS-PWM strategy can be implemented with one carrier reduced, which makes it much easier to implement in a digital signal processor (DSP) system. Experimental results have been presented to verify the effectiveness of the proposed inverter and the PS-PWM strategy.

• Journal of Power Electronics
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• 제10권4호
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• pp.365-373
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• 2010

This paper proposes a hybrid single carrier sinusoidal modulation suitable for multiphase multilevel inverters. Multiphase multilevel inverters are controlled by hybrid modulation to provide multiphase variable voltage and a variable frequency supply. The proposed modulation combines the benefits of fundamental frequency modulation and single carrier sinusoidal modulation (SC-SPWM) strategies. The main characteristics of hybrid modulation are a reduction in switching losses and improved harmonic performance. The proposed algorithm can be applied to cascaded multilevel inverter topologies. It has low computational complexity and it is suitable for hardware implementations. SC-SPWM and its base modulation design are implemented on a TMS320F2407 digital signal processor (DSP). A Complex Programmable Logic Device realizes the hybrid PWM algorithm and it is integrated with a DSP processor for hybrid SC-SPWM generation. The feasibility of this hybrid modulation is verified by spectral analysis, power loss analysis, simulation and experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 추계학술대회 논문집
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• pp.54-58
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• 2004

본 연구에서는 고정 주파수를 갖는 유사 랜덤 주파수 캐리어 PW(PRC-PWM)을 제안하고 단상 5-레벨 캐스케이드 인버터에 적용하였다. 제안된 PRC-PWM의 펄스는 고정 주파수를 갖는 삼각파 캐리어와 그 역상의 삼각파 캐리어를 랜덤 비트 발생기(PRBS)에 의하여 랜덤하게 선택함으로서 새롭게 합성된 랜덤 주파수의 캐리어에서 얻고 있다. 제안된 PRC-PWM은 고정 주파수의 캐리어 합성만으로 랜덤 주파수의 캐리어를 매우 간단하게 구현할 수 있으며, R-L부하와 연결된 단상 5-레벨 캐스케이드 인버터를 제작하여 타당성을 입증하였다.

• 전력전자학회논문지
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• 제27권6호
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• pp.526-534
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• 2022

The modular multilevel converter (MMC) has been widely applied to various industrial areas because of its various advantages and structural characteristics. Therefore, many methods for synthesizing the output voltage of MMC have been studied. Among these methods, phase-shifted pulse width modulation (PSPWM) is frequently used in MMC systems because it has diverse merits, such as excellent output qualities even with a small number of cells and uniform power distribution among cells. In this study, the total harmonic distortion (THD) of the output voltage is analyzed in accordance with the number of cells in one arm of a single-delta bridge cell MMC in order to compare PSPWM methods in terms of the THD of the output voltage. The physical characteristics of the triangle and sawtooth carrier waves used for the PSPWM and the mathematical modeling of output voltage are introduced. Then, the obtained results are verified through real-time simulation of a 1 MW single-delta bridge cell MMC system.