• Title/Summary/Keyword: PWM (Pulse-Width Modulation)

Search Result 717, Processing Time 0.025 seconds

New Technique to Generate the PWM Signal

  • Pongswatd, Sawai;Masuchun, Ruedee;Smerpitak, Krit;Ukakimapurn, Prapart
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2004.08a
    • /
    • pp.252-255
    • /
    • 2004
  • This paper presents a new technique to generate the 1-bit signal by decoding Pulse Width Modulation (PWM) signal to a binary file before programming onto the ROM. Since each PWM signal requires only 1-bit digital signal, PWM signal and other forms of digital signal related to multi-bit can be simply generated. The results demonstrate that using this new technique to generate the PWM signal can simplify the process and hardware complication. Moreover, the signal's data and frequency can be easily modified by programming the data onto the ROM and using the counter, respectively, which can reduce the size of the circuit and make the PCB easier.

  • PDF

A Simplified Carrier-Based Pulse-Width Modulation Strategy for Two-level Voltage Source Inverters in the Over-modulation Region

  • Jing, Feng;He, Feng-You
    • Journal of Power Electronics
    • /
    • v.17 no.6
    • /
    • pp.1480-1489
    • /
    • 2017
  • In this study, a carrier-based pulse-width modulation (PWM) method for two-level voltage source inverters in the over-modulation region is proposed. Based on the superposition principle, the reference voltage vectors outside the linear modulation boundary are adjusted to relocate to the vector hexagon, while their fundamental magnitudes are retained. In accordance with the adjusted reference vector, the corresponding modulated waves are respectively deduced in over-modulation mode I and II to generate the gate signals of the power switches, guaranteeing the linearity of the fundamental output phase voltage in the over-modulation region. Moreover, due to the linear relationship between the voltage vector and the duty ratios, the complicated sector identification and holding angle calculation found in previous methods are avoided in the modulated wave synthesis, which provides great simplicity for the proposed carrier-based over-modulation strategy. Experimental results demonstrate the effectiveness and validity of the proposed method.

Composition Modulation of Dot-matrix Display Grayscale (Dot-Matrix 디스플레이의 PWM방식과 PAM방식의 혼합 계조표현 법)

  • Hwang, Seon-Nam;Jung, Yong-Min;Lee, Jun-Young
    • Journal of the Semiconductor & Display Technology
    • /
    • v.5 no.3 s.16
    • /
    • pp.37-41
    • /
    • 2006
  • In this paper, a composition modulation of Dot-matrix display grayscale is presented. There's two method of expression of Dot-matrix Display grayscale. One is PWM by controlling pulse width. The other is PAM by controlling pulse amplitude. Composition modulation of Dot-matrix use PWM and PAM together. Composition modulation shows the number of grayscale as number of grayscale of PWM$\times$number of grayscale of PAM and have the effect of reduced size than existing single modulation.

  • PDF

Implementation of DC/DC Power Buck Converter Controlled by Stable PWM (안정된 PWM 제어 DC/DC 전력 강압 컨버터 구현)

  • Lho, Young-Hwan
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.18 no.4
    • /
    • pp.371-374
    • /
    • 2012
  • DC/DC switching power converters produce DC output voltages from different stable DC input sources regulated by a bi-polar transistor. The converters can be used in regenerative braking of DC motors to return energy back in the supply, resulting in energy savings for the systems containing frequent stops. The voltage mode DC/DC converter is composed of a PWM (Pulse Width Modulation) controller, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an inductor, and capacitors, etc. PWM is applied to control and regulate the total output voltage. It is shown that the output of DC/DC converter depends on the variation of threshold voltage at MOSFET and the variation of pulse width. In the PWM operation, the missing pulses, the changes in pulse width, and a change in the period of the output waveform are studied by SPICE (Simulation Program with Integrated Circuit Emphasis) and experiments.

Study about a density (ph) change of an alkaline ion by PWM voltage control necessary for a living body (PWM 전압제어로 생체에 필요한 알칼리 이온수의 농도(ph)변화에 관한 연구)

  • 권윤중;이성창
    • Journal of the Institute of Electronics Engineers of Korea SC
    • /
    • v.41 no.6
    • /
    • pp.37-42
    • /
    • 2004
  • It is necessary for what just keep a living body balance be devoted to it being varied with acidity serious trouble, and constitution of a study person about the density (ph) change that an alkaline ion necessary for a living body is numerical to supply a human body with number alkali by PWM voltage control. Works in the water which included the calcium (Ca), kalium (K), magnesium (Mg), natrium (Na) back who is helpful for a human body, and there is Alkaline. It is done this alkaline electrolysis to ask in order to create a number, and minerals are gathered through isolated layer (isolated special layer) to a - electrode direction, and is created. of course, prominent derelicts gather, and the acidity capital is happened, and -ion of a chlorine (Cl), phosphorus(P), sulfur (S) back is usable unfavorably in water of different use to a + electrode direction. Microprocessor was used with a - pole and a + pole with a PWM(pulse width modulation) voltage in this electrolysis process, and four kinds of PWM voltages were implemented, and a voltage every ph density change tried to be considered. It is expected by getting exactly if number alkaline ion of ph density value necessary is done with setting value if PWM control is used thus.

Single-Phase Step-Up Five-Level Inverter with Phase-Shifted Pulse Width Modulation

  • Chen, Jianfei;Wang, Caisheng;Li, Jian
    • Journal of Power Electronics
    • /
    • v.19 no.1
    • /
    • pp.134-145
    • /
    • 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.

The PWM Control Which used Microprocessor for Intensity Control of Acid Ion Water (산성이온수 농도제어를 위한 Microprocessor를 이용한 PWM 제어)

  • Kwon, Yunjung;Nam, Sangyep
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.50 no.7
    • /
    • pp.269-274
    • /
    • 2013
  • We are used with the alkaline ion water which an application field does to object for drinking water compare with the alkaline ion water which asked ion acid electrolysis so as to be very different. This is used with sterilization disinfection use by residual chlorine in case of strong acidity according to ph intensity, and in case of middle acidity use by washing and face washing, and mix with meal materials in case of weak acidity widely usable in cooking. Acid ion water generates as we electrolyze water. Chlorine gas and sodium hydroxide etc. was generated at electrolysis process, and we have toward sterilizing power. Derelicts such as chlorine, phosphorus, sulfur etc. are gathered from a negative ion, and we make acid ion water to + electrode direction in electrolysis. We used a diaphragm in order to disconnect too acid water and alkaline water. We implemented so that the acid water which it came down to three kinds of PWM voltage to PWM (pulse width modulation) control, and implementation method of ph intensity change authorized ph intensity between weak acidity to electrode in strong acidity as we used Microprocessor, and intensity was adjusted successively by PWM control was generated.

A Ripple Rejection Inherited RPWM for VSI Working with Fluctuating DC Link Voltage

  • Jarin, T.;Subburaj, P.;Bright, Shibu J V
    • Journal of Electrical Engineering and Technology
    • /
    • v.10 no.5
    • /
    • pp.2018-2030
    • /
    • 2015
  • A two stage ac drive configuration consisting of a single-phase line commutated rectifier and a three-phase voltage source inverter (VSI) is very common in low and medium power applications. The deterministic pulse width modulation (PWM) methods like sinusoidal PWM (SPWM) could not be considered as an ideal choice for modern drives since they result mechanical vibration and acoustic noise, and limit the application scope. This is due to the incapability of the deterministic PWM strategies in sprawling the harmonic power. The random PWM (RPWM) approaches could solve this issue by creating continuous harmonic profile instead of discrete clusters of dominant harmonics. Insufficient filtering at dc link results in the amplitude distortion of the input dc voltage to the VSI and has the most significant impact on the spectral errors (difference between theoretical and practical spectra). It is obvious that the sprawling effect of RPWM undoubtedly influenced by input fluctuation and the discrete harmonic clusters may reappear. The influence of dc link fluctuation on harmonics and their spreading effect in the VSI remains invalidated. A case study is done with four different filter capacitor values in this paper and results are compared with the constant dc input operation. This paper also proposes an ingenious RPWM, a ripple dosed sinusoidal reference-random carrier PWM (RDSRRCPWM), which has the innate capacity of suppressing the effect of input fluctuation in the output than the other modern PWM methods. MATLAB based simulation study reveals the fundamental component, total harmonic distortion (THD) and harmonic spread factor (HSF) for various modulation indices. The non-ideal dc link is managed well with the developed RDSRRCPWM applied to the VSI and tested in a proto type VSI using the field programmable gate array (FPGA).

Reduction of Audible Switching Noise in Induction Motor Drives Using Random Position PWM (Random Position PWM을 이용한 유도전동기의 가청 스위칭 소음 저감)

  • 나석환;임영철
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.3 no.4
    • /
    • pp.287-297
    • /
    • 1998
  • RPWM(Random Pulse Width Modulation) is a switching technique to spread the voltage and current harmonics on wide frequency area. Using randomly changed switching frequency of the inverter, the power spectrum of the electromagnetic acoustic noise can be spread into the wide-band area. And the wide-band noise is much more comfortable and less annoying than the narrow-band one. So RPWM have been attracting an interest as an excellent reduction method of acoustic noise on the inverter drive system. In this paper a new RPPWM(Random Position PWM) is proposed and implemented. Each of three pulses is located randomly in each switching intervals. Along with the randomization of PWM pulses, the space vector modulation is processed on the C167 microcontroller also. The experimental results show that the voltage and current harmonics were spread into wide band area and that the audible switching noise was reduced by proposed RPPWM method.

  • PDF

Performance Comparison of Common-Mode Voltage Reduction Methods in terms of Modulation Index (변조지수에 따른 공통모드 전압 저감 기법 성능 비교)

  • Heo, Geon;Park, Yongsoon
    • Proceedings of the KIPE Conference
    • /
    • 2020.08a
    • /
    • pp.106-108
    • /
    • 2020
  • This paper introduces a new pulse-width modulation (PWM) method to reduce common-mode voltages (CMVs) and compare its performance with other reduced CMV-PWM (RCMV-PWM) methods. To avoid the use of zero-vectors which cause high CMV peaks, the introduced method splits every reference vector into two vectors such that the peak-to-peak magnitude of CMV is reduced by one-third of conventional space-vector PWM (SVPWM). The performance of RCMV-PWMs altered by the modulation index are analyzed with simulation results.

  • PDF