• Title/Summary/Keyword: pulse width modulation

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Design of 5'' True Color FED Driving System (5'' True Color FED 구동시스템 설계)

  • Shin, Hong-Jae;Kwon, Oh-Kyong;Kwack, Kae-Dal
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.38 no.5
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    • pp.70-78
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    • 2001
  • We have developed a novel driving system of 5' true color FED using voltage controlled PWM method which has current control effect. The proposed method has the advantage of voltage controlled pulse width modulation method and current control method. Also, we propose a new circuit model of FED subpixel for circuit simulation of FED driving circuits, considering some parasitic effects, i.e., cross talk, line coupling effect and leakage current to the adjacent cathode lines. Output stage of the data driving circuit is optimized using the proposed circuit model. In video data processing, FED controller uses the parallel processing of R.G.B input data, so duty ratio is maximized and brightness of FED increases. With this results, no noise and high quality performance is achieved in display of 5' true color FED.

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Fault Diagnosis of Solar Power Inverter Using Characteristics of Trajectory Image of Current And Tree Model (전류 궤적 영상의 특징과 트리모델을 이용한 태양광 전력 인버터의 고장진단)

  • Hwang, Jae-Ho
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.47 no.4
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    • pp.102-108
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    • 2010
  • The photovoltaic system changes solar energy into DC by solar cell and this DC is inverted into AC which is used in general houses by inverter. Recently, the use of power of the photovoltaic system is increased. Therefore, the study of 3 phase solar system to transmit large power is very important. This paper proposes a method that finds simply faults and diagnoses the switch open faults of 3-phase pulse width modulation (PWM) inverter of grid-connected photovoltaic system. The proposed method in $\alpha\beta$ plane uses the patterns of trajectory image as the characteristic parameters and differenciates a normal state and open states of switches. Then, the result is made into tree. The tree is composed of 21 fault patterns and the parameters to classify faults are a shape, a trajectory area, a distributed angle, and a typical vector angle. The result shows that the proposed method diagnosed fault diagnoses, classified correctly them, and made a pattern tree by fault patterns.

The Measurement of 3-Phase Current with Single Current Sensor and the Compensation of Voltage Distortion in Carrier-Based PWM Technique (삼각파 비교 PWM 기법에 있어서 단일 전류센서에 의한 삼상 전류 측정 및 전압 왜곡 보상)

  • 김경서
    • The Transactions of the Korean Institute of Power Electronics
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    • v.8 no.3
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    • pp.292-298
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    • 2003
  • Most of the three phase inverters for adjustable speed drive of AC machines are equipped with two or three current sensors for measurement of three phase current. One method to reduce the number of current sensors is that single current sensor measures the DC link current, then three phase current is reconstructed using the measured value and the switching status. To improve the measurement accuracy, switching state should be maintained for more than minimum switching time. Many papers have been published, which focused on the readjustment of pulse width and compensation of voltage distortion. Those methods are suitable for space vector modulation. But there are some difficulties in applying these methods to carrier-based PWM which is widely used in industry. In this paper, new current measurement method and voltage compensation method are proposed which are suitable for carrier-based PWM, then, the validity of proposed method is confirmed through experiment.

A Stereo Audio DAC with Asymmetric PWM Power Amplifier (비대칭 펄스 폭 변조 파워-앰프를 갖는 스테레오 오디오 디지털-아날로그 변환기)

  • Lee, Yong-Hee;Jun, Young-Hyun;Kong, Bai-Sun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.7
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    • pp.44-51
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    • 2008
  • A stereo audio digital-to-analog converter (DAC) with a power amplifier using asymmetric pulse-width modulation (PWM) is presented. To adopt class-D amplifier mainly used in high-power audio appliances for head-phones application, this work analyzes the noise caused by the inter-channel interference during the integration and optimizes the design of the sigma-delta modulator to decrease the performance degradation caused by the noise. The asymmetric PWM is implemented to reduce switching noise and power loss generated from the power amplifier. This proposed architecture is fabricated in 0.13-mm CMOS technology. The proposed audio DAC including the power amplifier with single-ended output achieves a dynamic range (DR) of 95-dB dissipating 4.4-mW.

A Novel Half-Bridge Resonant Inverter With Load Free-wheeling Modes (부하 환류모드를 갖는 새로운 하프 브리지 공진형 인버터)

  • Yeon Jae-Eul;Cho Kyu-Min;Kim Hee-Jun
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.42 no.3 s.303
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    • pp.71-80
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    • 2005
  • This paper proposes a new circuit topology of the half-bridge resonant inverter and presents its digital control scheme. As the proposed half-bridge inverter can be operated in the load-freewheeling modes, pulse width modulation (PWM) control method can be used for the output power control. The proposed half-bridge inverter can keep unity output displacement factor under the load-impedance varying conditions, if a new PWM control scheme based on the resonant frequency tracking algorithm is adopted. In this paper, the operation principle, electrical characteristics and detailed digital control scheme of the proposed half-bridge resonant inverter and loss analysis comparing with a conventional half bridge inverter is described. The experimental results of the proto-type experimental setup to verify the validity of the proposed half-bridge resonant inverter are presented and discussed.

A Study on the Charge Controller for Solar Street Lamp by Direct Duty Ratio Control (다이렉트 듀티비 제어에 의한 태양광 가로등용 충전제어기에 관한 연구)

  • Jang, Han-Gi;Lim, Jung-Yeol
    • Journal of IKEEE
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    • v.19 no.1
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    • pp.118-123
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    • 2015
  • According to the recent report, solar street lamp connected to a non Maximum Power Point Tracking(MPPT) charger, can lead to a system-wide decline in power output with as much as 30%. This paper proposes the charge controller with direct duty ration control for 250W solar street lamp in order to improve the efficiency of photovoltaic from these output power reduction. This paper covers the Pulse Width Modulation(PWM) controller and power conversion topology and analyze the MPPT method for charge controller. The power conversion part consists of push pull converter based on PWM controller using 8bit MCU in order to have lower manufacturing cost. The PWM controller with direct duty ratio control algorithm is constantly tracking the maximum power point of photovoltaic module and increases energy output power. The test results shows 97.1~97.4% MPPT efficiency and the experimental hardware is implemented based on the solar simulator condition for 241W. Thus, the implemented charge controller shows its feasibility for the real application, especially under solar street lamp.

A Study on DC Traction Power Supply System Using PWM Converter (PWM컨버터를 적용한 경전철 전력공급시스템에 관한 연구)

  • Kim, Joorak;Park, Chang-Reung;Park, Kijun;Kim, Joo-Uk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.4
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    • pp.250-254
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    • 2016
  • Currently, power conversion system which converts AC to DC Power is applied in domestic urban railway. The diode rectifier is used in most of them. However the diode rectifier can not control the output voltage and can not regenerate power as well. On the other hand, PWM (pulse width modulation) converter using IGBT (isolated gate bipolar transistor) can control output voltage, allowing it to reduce the output voltage drop. Moreover the Bi-directional conduction regenerates power which does not require additional device for power regeneration control. This paper compared the simulation results for the DC power supply system on both the diode rectifier and the PWM converter. Under the same load condition, simulation circuit for each power supply system was constructed with the PSIM (performance simulation and modeling tool) software. The load condition was set according to the resistance value of the currently operating impedance of light rail line, and the line impedance was set according to the distance of each substations. The train was set using a passive resistor. PI (proportional integral) controller was applied to regulate the output voltage. PSIM simulation was conducted to verify that the PWM Converter was more efficient than the diode rectifier in DC Traction power supply system.

Effect of Swirl Angle on the Atomization Characteristics in Two-Fluid Nozzle with Dual Air Supplying System (이중공기공급 이유체노즐의 선회각 변화에 따른 분무특성)

  • Kim, E.S.;Kang, S.M.;Choi, Y.J.;Kim, D.J.;Lee, J.K.;Rho, B.J.
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.54-60
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    • 2008
  • The atomization characteristics of the dual air supplying twin-fluid nozzle were investigated experimentally using PIV and PDA systems. The two-fluid nozzle is composed of three main parts: the feeding injector to supply fluid that is controlled by a PWM (pulse-width modulation) mode, the adaptor as a device with the ports for supplying the carrier and assist air and the main nozzle to produce the spray. The main nozzle has the swirl tip with four equally spaced tangential slots, which give the injecting fluid an angular momentum. The angle of the swirl tip varied with 0$^{\circ}$ 30$^{\circ}$, 60$^{\circ}$ and 90$^{\circ}$, and the ratios of carrier air to assist air and ALR(total air to liquid) were 0.55 and 1.23, respectively. The macroscopic behavior of the spray was investigated using PIV system, and the mean velocity, turbulent intensity and SMD distributions of the sprays were measured using PDA system. As the results, the mean axial velocity at the spray centerline decrease with the increase of the swirl angle. The turbulent intensities of the axial and radial velocity were increased with the increase of the swirl angle. The mean SMD (Sauter mean diameter) of the radial direction along the axial distance shows the lowest value at the swirl angle of 60$^{\circ}$.

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Characteristic of VSI Driven by Source Synchronous Type for the Utility Interactive using a Photovoltaic Generation for the LED Luminaire Emergency Exit Sign Operation (LED 비상 유도등 동작을 위한 태양광발전 계통연계 전원동기 방식의 전압형 인버터 구동 특성)

  • Hwang, Lark-Hoon;Na, Yong-Ju
    • Journal of Advanced Navigation Technology
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    • v.22 no.5
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    • pp.420-428
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    • 2018
  • In this paper, represented uninterruptible power supply (UPS) equipment maintaining constant output voltage, the proposes a photovoltaic system constructed with a step up boosting chopper and single phase pulse width modulation (PWM) voltage source inverter. as power source disconnection, voltage variation and output current variation with load variation. This system is driven by being synchronized voltage fed inverter and AC source, and in the steady state of power source charge battery connected to DC side with solar cell using a Photovoltaic that it was so called constant voltage charge. It can be results of saving electric power, and through a normal operation of energy storage system (ESS), the system operated the LED a calling on signal changes at the airport in an efficient manner. In addition, better output waveform was generated because of PWM method, and it was proved to test by experiment maintained constant output voltage regardless of AC source disconnection, load variation, and voltage variation of AC power source.

Design of a DSP Controller and Driver for the Power-by-wire(PBW) System Using BLDC Servo Motor (BLDC 전동기를 이용하는 직동력(PBW) 구동시스템의 제어기 및 구동기 설계)

  • Joo, Jae-Hun;Goo, Bon-Min;Kim, Jin-Ae;Zo, Dae-Seong;Choi, Jung-Keyng
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.897-900
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    • 2007
  • This paper presents a study on the DSP controller and IGBT inverter driver design for the power-by-wire(PBW) system using BLDC servo motor. This BLDC servo motor system was realized with DSP(Digital Signal Processor) and IGBT inveter module. The PBW system needs speed control of servo motor for linear thrust action. This paper implements a servo controller with vector control and min-max PWM technique. As CPU of controller, TMS320F2812 DSP was adopted because it has PWM(Pulse Width Modulation) waveform generator, A/D(Analog to Digital) converter, SPI( Serial Peripheral Interface) port and many input/output port etc.

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