• Title/Summary/Keyword: PWM Capability

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Novel Converter Topology for a Three Phase to Three Phase PWM Rectifier/Inverter System (비용절감형 컨버터 구조를 갖는 3상-3상 PWM 정류기/인버터 시스템)

  • Kim, Gi-Taek;Park, Tae-Yeol;Lee, Hae-Chun
    • Journal of Industrial Technology
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    • v.18
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    • pp.323-328
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    • 1998
  • A current controlled VSI-PWM rectifier and inverter with capacitor dc link is regarded as one of the most promising structures for three-phase to three-phase to three-phase power conversion. This type of converter normally requires twelve switches for a rectifier and inverter composed of self turn-off switch such as a bi-polar transistor or IGBT with an anti-parallel diode. In this paper, a new three-phase to three-phase converter for ac motor drives is proposed. The proposed converter employs only eight switches and has the capability of delivering sinusoidal input currents with unity power factor and bidirectional power flow. This paper describes the feasibility and the operational limitations of the proposed structure. A mathematical model of the system is derived using generalized modulation theory and experimental results for steady state and dynamic behavior are presented to verify the developed model.

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IP Voltage Controller of Three-phase PWM Converter for Power Supply of Communication System (IP 제어기를 이용한 통신 전원용 3상 PWM 컨버터의 전압 제어)

  • Shin, Hee-Keun;Kim, Hag-Wone;Cho, Kwan-Yuhl;Ji, Jun-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.6
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    • pp.2722-2728
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    • 2011
  • 3Phase PWM rectifier has become increasingly popular due to its capability of nearly sinusoidal waveform of the input current, and nearly unity power factor operation as a AC/DC rectifier of high capacity telecommunication power supply system. Generally, PI controller is used as a voltage controller of PWM rectifier and voltage controller must be designed to have low overshoot in transient state to get a reliability and stable operation. However, in the application of telecommunication in which load condition is varied very fast, the voltage controller must have a large bandwidth to reduce output voltage variation. The PI controller with large bandwidth arouse the excessive overshoot of the output voltage, and this large output voltage variation degrades the reliability of communication power of the three-phase PWM Rectifier. In this paper, new IP voltage controller for 3 phase PWM rectifier is proposed which has relatively low transient output voltage variation. The improved output characteristics of the transient state voltage responses of the starting and at load changes of the proposed voltage controller are proved by simulations and experiments.

Design and Implementation of LED Lighting System with Adjustable Brightness and Color Capability (색상 및 밝기 조절이 가능한 LED 조명 기구의 설계 및 구현)

  • Kwak, Seong-Woo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.5
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    • pp.579-586
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    • 2015
  • In this paper, we design and implement a lighting system which has a capability of adjusting brightness and colors of LED module. The lighting systems is consisted of RGB and white LEDs controlled by a micro-processor. All colors in nature can be synthesized in our lighting system by controlling brightness of 4 color LEDs individually. The current flowing to LED is limited to a maximum set value to extend the LED life time using PWM current control. The control module also includes the function that it can save and load brightness and color data set by the user. The implemented lighting system passed the electromagnetic compatibility(EMC) test such that it can be used as a commercial product.

A Study on Control and Compensating Characteristics of Active Series Voltage Compensator with Harmonic Current Compensating Capability (고조파전류 보상 기능을 갖는 능동 직렬 전압보상기의 제어 및 보상특성에 관한 연구)

  • 이승요;김홍성;최규하;신우석;김홍근
    • The Transactions of the Korean Institute of Power Electronics
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    • v.5 no.5
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    • pp.484-492
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    • 2000
  • In this paper, a voltage compensator with harmonic current compensating capability is studied and its compensating characteristics are analyzed. Like the hybrid active power filter, the proposed system is composed of parallel LC passive filter and series PWM converter connected to power line through series transformer. It is shown that the compensation of harmonic current generated due to nonlinear loads such as diode rectifier and instantaneous voltage compensation of the source are performed through the proposed compensating system. The operating principle of the proposed system is described through a single-phase equivalent circuit and the control strategy is suggested on the d-q rotating reference frame of the 3-phase system. Also, experiment is carried out to verify compensating characteristics of the proposed system.

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PWAM Based THD Reduction of Inverter for Air-Conditioning Blower (PWAM 방식을 이용한 공조시스템용 인버터의 THD 저감 방법)

  • Lim, Seung-Beom;Lee, Yun-Ha;Zun, Chan-Yong
    • Proceedings of the KIPE Conference
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    • 2011.07a
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    • pp.97-98
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    • 2011
  • The HVAC(Heating Ventilation and Air conditioning) system is controlled by two ways, one is ON/OFF control and the other is PWM inverter with V/F. Control of blower with the use of PWM inverter has quite some benefits such as the capability of changing speed, high efficiency and reduced noise level compared with ON/OFF control. But if blower is operated at low speed, high THD generated by decrease of ma, and output voltage lowered in proportion to frequency. To solve these problems, filter should be installed at the output stage of inverter, which can decrease THD but has problems such as increase of volume size and additional braking resistance. This paper proposes the PWAM method which can reduce THD instead of installing the filter at the output stage of inverter. The proposed PWAM method is an inverter modulation method that fixes the modulation index of inverter to reduce THD by varying DC link voltage of inverter unlike conventional PWM method. Finally, the validity of proposed PWAM methods verified by experiments.

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A New PWM-Controlled Quasi-Resonant Converter for High Efficiency PDP Sustaining Power Module (고효율의 PDP 유지 구동 전원단을 위한 새로운 펄스폭 제어방식의 쿼지 공진 컨버터)

  • Lee Woo-Jin;Choi Seong-Wook;Kim Chong-Eun;Moon Gun-Woo
    • Proceedings of the KIPE Conference
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    • 2006.06a
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    • pp.352-355
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    • 2006
  • A new PWM-controlled quasi-resonant converter for high efficiency PDP sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the resonant capacitor with hi-directional auxiliary circuit, while the main switches are operating at the fixed duty ratio and fixed switching frequency. Hence, the waveform of currents can be expected to be optimized on the conduction loss. Furthermore, the proposed converter shows the good ZVS capability, simple control circuits, no high voltage ringing problem of rectifier diodes, no DC offset of the magnetizing current and low voltage stress of power switches. In this paper, operational principles, analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit as PWM method.

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A New PWM-Controlled Quasi-Resonant Converter for a High Efficiency PDP Sustaining Power Module

  • Lee, Woo-Jin;Choi, Seong-Wook;Kim, Chong-Eun;Moon, Gun-Woo
    • Journal of Power Electronics
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    • v.7 no.1
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    • pp.28-37
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    • 2007
  • A new PWM-controlled quasi-resonant converter for a high efficiency PDP sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the resonant capacitor with a bi-directional auxiliary circuit, while the main switches are operating at a fixed duty ratio and fixed switching frequency. Hence, the waveforms of the currents can be expected to be optimized from the view-point of conduction loss. Furthermore, the proposed converter has good ZVS capability, simple control circuits, no high voltage ringing problem of rectifier diodes, no DC offset of the magnetizing current and low voltage stresses of power switches. In this paper, operational principles, features of the proposed converter, and analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit using the PWM method.

Analysis of Step-up AC/DC Converter (승압형 AC/DC 전력 변환기의 해석)

  • Park, S.Y.;Park, I.G.;Kang, Y.S.;Park, J.K.
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.340-343
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    • 1990
  • Recently, Power Electronics system increase makes harmonics and low input power factor problem. In this paper present new analysis method of PWM Boost AC/DC Converter. This PWM AC/DC Converter is capability of unity power factor, control of DC side voltage level, generation, and near sinusoidal current in 3-phase line. The control of this type of converter is widely discussed. And this paper propose new phase convert function and analysis in steady state of system to obtain amplitude and phaser of switching function. This switching function is general solution and it can use in high power approach. And this control method show the clear meaning of control variable. This paper propose new analysis method of Boost AC/DC Converter of steady state and 3-phase 2KW experimental system show its validity.

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Novel Two Stage AC-to-DC Converter with Single Switched Zero Voltage Transition Boost Pre-Regulator using DC-Linked Energy Feedback (새로운 영전압 스위칭 이단방식의 고역률 컨버터)

  • Roh, Chung-Wook;Moon, Gun-Woo;Jung, Young-Seok;Youn, Myung-Joong
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.385-387
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    • 1996
  • A novel two stage soft-switching ac-to-dc convener with power factor correction is proposed. The proposed convener provides zero-voltage-switching (ZVS) condition to main switch of boost pre-regulator without auxiliary switch. Comparing to the conventional two stage approach(ZVS-PWM boost rectifier followed by off-line ZVS dc-dc step down converter), the proposed approach is simple and reducing EMI noise problem. A new simple DC-linked energy feedback circuit provides zero-voltage-switching condition to boost pre-regulator without imposing additional voltage and current stresses and loss of PWM capability. Operational principle, analysis, control of the proposed converter together with the simulation results of 1KW prototype are presented.

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THREE PHASE PWM AC-DC BOOST CONVERTER WITH UNITY POWER FACTOR (단위 역률로 동작하는 3상 PWM AC-DC BOOST콘버어터에 관한 연구)

  • Chun, Chang-Gun;Park, Sung-Jun;Kwon, Soon-Jae;Kim, Chul-U
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.397-399
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    • 1994
  • In this parer, the development of input power factor and the harmonic distortion of line current were showed in the proposed three phase AC-DC converter. We identified that DC voltage in the output terminal has fast dynamic response and has nearly ripple. Moreover, the converter also possesses the regenerative capability which is useful for many applications. The switching frequency of this converter operated with constant in the range of 2KHZ. Finally, simulation and experiment results are presented.

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