• Title, Summary, Keyword: PWM technique

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Novel PWM Methods for Two-Leg and Four-leg Two-Phase Inverter Fed Two-Phase Induction Motor (2상 유도전동기 구동 2상 인버터를 위한 새로운 PWM제어방식 I - 2-레그 타입 및 4-레그 타입의 경우 -)

  • Jang Do-Hyun
    • The Transactions of the Korean Institute of Power Electronics
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    • v.10 no.4
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    • pp.331-338
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    • 2005
  • In this paper the novel pulsewidth modulation(PWM) technique for the two-leg and four-leg two-phase inverter is proposed. The conventional space vector PWM technique for two-phase inverter was complex. The proposed PWM for two-leg inverter, which is used by sinusoidal PWM method, is simpler than the conventional SVPWU technique. Also, a simple PWM technique for four-leg two-phase inverter is proposed. Such PWM technique is based on PWM technique for two-leg inverter. Practical verification of theoretical predictions is presented to confirm the capabilities of the new techniques.

A Novel Random PWM Technique with a Constant Switching Frequency Utilizing an Offset Voltage (옵셋 전압을 이용한 일정 스위칭 주파수의 Random PWM 기법)

  • Kim, Do-Kyeom;Kim, Sang-Hoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.22 no.1
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    • pp.67-74
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    • 2017
  • This study proposes a novel random pulse-width modulation (PWM) technique with a constant switching frequency utilizing a random offset voltage. The proposed PWM technique spreads switching harmonics by varying the position of an active voltage vector without a switching frequency variation. The implementation of the proposed PWM technique is simple because it does not require additional hardware and complex algorithm. The proposed random PWM technique is compared with the conventional PWM technique on the factors of harmonic spectrum, total harmonic distortion, and harmonic spread factor to confirm the harmonic spread effect. The validity of the proposed method is verified by simulations and experiments on a three-phase inverter drive system.

New PWM Technique for Two-Phase Brushless DC Motor Drives

  • Lin, Hai;Kwon, Byung-Il
    • Journal of Electrical Engineering and Technology
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    • v.8 no.5
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    • pp.1107-1115
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    • 2013
  • A new PWM technique for a two-phase BLDC motor fed by a two-phase eight-switch inverter is proposed in this paper. It is well known that a two-phase eight-switch inverter can significantly improve power output compared with a two-phase six-switch inverter in a two-phase motor drive. To drive the two-phase BLDC motor simply and effectively, two normal PWM strategies are investigated to manage speed regulation. However, under the conditions of low speed and light load, especially during the braking process, the current in a short time of one period is near zero, which is a discontinuous waveform every half period. To solve it, a novel PWM technique is investigated to improve the operational performance of normal technique. Using the new PWM scheme, the current continues every half period and the braking performance is improved. The effectiveness of the proposed PWM method is verified through the experiments.

A Switching Technique for Common Mode Voltage Reduction of PWM-Inverter Induction Motor Drive System Using TMS320F240 (TMS320F240을 이용한 PWM 인버터 유도전동기 구동 시스템의 전도노이즈 저감을 위한 스위칭 기법)

  • 박규현;김이훈;원충연;김규식;최세완;함년근
    • The Transactions of the Korean Institute of Power Electronics
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    • v.8 no.1
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    • pp.89-97
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    • 2003
  • High frequency common mode voltage produced by PWM inverter fed Induction motor is a major cause of conducted EMI, creation motor ground currents, bearing currents and other harmful products. The zero switching states of inverter control invoke large in comparison with the non-zero switching state of Inverter control. We proposed a common mode voltage reduction method based on sinusoidal PWM technique. PWM signal are generated by comparing respective sinusoidal reference signal with three triangular carrier wave displaced of 120$^{\circ}$. Simulation and experimenta1 result show that common mode voltages in the proposed PWM technique are reduced by approximate 66% more than conventional FWM technique.

Carrier Based Single-State PWM Technique for Minimizing Vector Errors in Multilevel Inverters

  • Nho, Nguyen Van;Hai, Quach Thanh;Lee, Hong-Hee
    • Journal of Power Electronics
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    • v.10 no.4
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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.

A Study on the PWM Generation using Time Average Model (시평균화방법을 이용한 PWM 신호발생에 관한 연구)

  • Hong, Soon-Wook;Cha, Jae-Deok;Cho, Kyu-Bock
    • Proceedings of the KIEE Conference
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    • pp.1088-1091
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    • 1992
  • Programmed PWM(Pulse Width Modulated) generation techniques eliminating several low order harmonics have been widely used in the inverter circuit which produces minimum current ripple, reduced torque pulsation and thereby improves overall system performance. However, the applications of the programmed PWM technique are limited to CVCF(Constant Voltage Constant Frequency) applications and various motor drives. Although the programmed PWM produces a lower harmonic distorted waveform than the carrier modulated PWM, real-time programming is not possible because of the complicated calculation required for the gating signal. In this paper, a new programmed PWM technique named TAM (time averaging model) is developed to compensate for the demerits of the conventional programmed PWM technique with moderate harmonic distortion. Computer simulations are performed to verify the performance of the proposed algorithm.

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The Implementation of Sub-MRA PWM Technique Using DSP (DSP를 이용한 Sub-MRA PWM 기법의 실현)

  • 이성백;이종규;원영진;한완옥;박진홍
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.8 no.2
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    • pp.41-45
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    • 1994
  • In this paper, it is implemented that Sub- MRA PWM techinque which is applied to MRA PWM technique using the Digital Signal Processor. Unstable element of analog is reduced for Sub - MRA PWM technique by digital signal pressing. And harmonic is analized by simulation to verify that. It is afford the process induction motor control with real time by minimizing the delay time of digital system. Time delay which is a defect of digital control can by minimized using fast caculation. Therefore, real time control is implemented in the induction motor

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A Study on The MRA PWM Technique Using the Trapezoidal Waveform at Voltage Source Inverter(VSDI) (전압형 인버터(VSI)에서 사다리꼴파형을 이용한 MRA PWM 기법에 관한 연구)

  • 한완옥;원영진;이성백
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.7 no.2
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    • pp.36-40
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    • 1993
  • In order to improve complicated construction and complex control which are disadvantage of optimal PWM technique aimed at harmonic elimination method, this paper presented MRA(Model Reference Adaptive) PWM technique that gatmg signal of inverter is generated by comparing the reference signal with the induced feedback signal at the reference model of load. Design of controller is composed of microprocessor and analog circuit. MRA PWM technique used in the paper is able to compensate the degradation of voltage efficiency to be generated by the ratio of the output voltage to the DC supply voltage being low for using conventional sinusoidal PWM technique. When the trapezoidal signal is employed as the reference signal. the low order harmonics of line current can be reduced and the switching pattern is made by on-line computation using comparatively simple numerical analysis.

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Synchronous Periodic Frequency Modulation Based on Interleaving Technique to Reduce PWM Vibration Noise

  • Zhang, Wentao;Xu, Yongxiang;Ren, Jingwei;Su, Jianyong;Zou, Jibin
    • Journal of Power Electronics
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    • v.19 no.6
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    • pp.1515-1526
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    • 2019
  • Ear-piercing high-frequency noise from electromagnetic vibrations in motors has become unacceptable in sensitive environments, due to the application of pulse width modulation (PWM) and in consideration of switching losses. This paper proposed a synchronous periodic frequency modulation (SPFM) method based on the interleaving technique for paralleled three-phase voltage source inverters (VSIs) to eliminate PWM vibration noise. The proposed SPFM technique is able to effectively remove unpleasant high-frequency vibration noise as well as acoustic noise more effectively than the conventional periodic carrier frequency modulation (PCFM) and interleaving technique. It completely eliminates the vibration noise near odd-order carrier frequencies and reduces the PWM vibration noise near even-order carrier frequencies depending on the switching frequency variation range. Furthermore, the SPFM method is simple to implement and does not employ additional circuits in the drive system. Finally, the effectiveness of the proposed method has been confirmed by detailed experimental results.

An Improved Wavelet PWM Technique with Output Voltage Amplitude Control for Single-phase Inverters

  • Zheng, Chun-Fang;Zhang, Bo;Qiu, Dong-Yuan;Zhang, Xiao-Hui;Li, Rui
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1407-1414
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    • 2016
  • Unlike existing pulse-width modulation (PWM) techniques, such as sinusoidal PWM and random PWM, the wavelet PWM (WPWM) technique based on a Harr wavelet function can achieve a high fundamental component for the output voltage, low total harmonic distortion, and simple digital implementation. However, the original WPWM method lacks output voltage control. Thus, the practical application of the WPWM technique is limited. This study proposes an improved WPWM technique that can regulate output voltage amplitude with the addition of a parameter. The relationship between the additional parameter and the output voltage amplitude is analyzed in detail. Experimental results verify that the improved WPWM exhibits output voltage control in addition to all the merits of the WPWM technique.