• Title/Summary/Keyword: high power factor

Search Result 1,902, Processing Time 0.032 seconds

A Study on Single-Stage High-Power-Factor Electronic Ballast for Discharge Lamps Operating in Critical Conduction Mode (임계모드에서 동작하는 단일 전력단 고역률 방전등용 전자식 안정기에 관한 연구)

  • Seo Cheol-Sik;Park Jae-Wook;Sim Kwang-Yeal;Kim Hae-Jun;Won Jae-Sun;Kim Dong-Hee
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.54 no.12
    • /
    • pp.601-608
    • /
    • 2005
  • This paper presents a novel single-stage high-power-factor electronic ballast for fluorescent lamps operating in critical conduction mode. The proposed topology is based on integration of boost converter as power factor corrector(PFC) and a half-bridge high frequency parallel resonant inverter into a single stage. The input stage of the boost converter is operating in critical conduction mode for positive and negative half cycle voltage respectively at line frequency(60Hz). So that a boost converter makes the line current follow naturally the sinusoidal line voltage waveform. The simulated and experimental results for 100W fluorescent lamps operating at 42kHz switching frequency and 220V line voltage have been obtained. This proposed inverter will be able to be practically used as a power supply in various fields as induction heating applications, fluorescent lamp and DC-DC converter etc.

A Single-Phase PWM Converter with fast response (빠른 응답성을 갖는 단상 PWM Converter)

  • 배기훈;기상우;최종묵
    • Proceedings of the KSR Conference
    • /
    • 1999.05a
    • /
    • pp.322-327
    • /
    • 1999
  • In most railway vehicle applications, a single phase AC/DC converter is used greatly and is essential equipment for Korea High Speed Train. A diode bridge rectifier and a phase-controlled thyristor bridge rectifier generate harmonics in power system. Nowadays, power factor and harmonics become major issue in electrical equipment for railway vehicle. Many researchers have been trying to improve the power factor and ac-side harmonics. Therefore the PWM converter is used to operate at unity Power factor and to reduce ac-side current harmonics. This paper describes the circuit for AC/DC PWM converter of Korea High Speed Train and proposes control algorithm to realize the sinusolidal input current waveform and the effective unity power factor. The validity of the proposed control method is verified through the experimental result.

  • PDF

Performance Improvement using Auxiliary Converter on HVDC System (보조 컨버터를 이용한 HVDC 시스템의 특성개선)

  • Kim, Dong-Hee;Lee, Hwa-Chun;Park, Sung-Jun;Nam, Hae-Kon;Choi, Joon-Ho;Kim, Kwang-Heon
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.58 no.2
    • /
    • pp.217-224
    • /
    • 2009
  • This paper presents a new AC/DC converter scheme for HVDC system to achieve a high power factor operation. The new AC/DC converter consists of two 12-pulse bridge converters in series: the primary and auxiliary converters. Ignition angles of the main and auxiliary converters are controlled independently to maintain the nominal DC voltage and control auxiliary voltage. The resulted DC voltage obtained by superimposing the above two phase modulated voltages can be controlled very rapidly over a wide range, and a high power factor operation is achieved. Performance improvements in power factor and harmonic distortion are validated by theoretic derivations and experiments with prototype HVDC system. With the proposed converters, investment for reactive power compensation and filter in HVDC system can be saved significantly.

Electrodeless Fluorescent Lamp System using A New ZVT-PWM boost Converter (ZVT-PWM 부스트 컨버터를 이용한 무전극 램프 구동 시스템)

  • Lee, H.M.;Lee, H.W.;Koh, H.S.
    • Proceedings of the KIEE Conference
    • /
    • 2003.07b
    • /
    • pp.1175-1177
    • /
    • 2003
  • In this paper, an application of the ZVT-PWM(zero-voltage-transition) boost converter, which has great advantage on miniaturization and high power density, to the power factor correction circuit of the EFL(electrodeless fluorescent lamp) inverter is studied. The operation principles of the converter are described to identify the power factor correction characteristic of the inverter. Experimentally obtaining the high power factor above 0.99, it is verified that the power factor correction of the EFL inverter successfully achieved.

  • PDF

Single-Phase Bridgeless Zeta PFC Converter with Reduced Conduction Losses

  • Khan, Shakil Ahamed;Rahim, Nasrudin Abd.;Bakar, Ab Halim Abu;Kwang, Tan Chia
    • Journal of Power Electronics
    • /
    • v.15 no.2
    • /
    • pp.356-365
    • /
    • 2015
  • This paper presents a new single phase front-end ac-dc bridgeless power factor correction (PFC) rectifier topology. The proposed converter achieves a high efficiency over a wide range of input and output voltages, a high power factor, low line current harmonics and both step up and step down voltage conversions. This topology is based on a non-inverting buck-boost (Zeta) converter. In this approach, the input diode bridge is removed and a maximum of one diode conducts in a complete switching period. This reduces the conduction losses and the thermal stresses on the switches when compare to existing PFC topologies. Inherent power factor correction is achieved by operating the converter in the discontinuous conduction mode (DCM) which leads to a simplified control circuit. The characteristics of the proposed design, principles of operation, steady state operation analysis, and control structure are described in this paper. An experimental prototype has been built to demonstrate the feasibility of the new converter. Simulation and experimental results are provided to verify the improved power quality at the AC mains and the lower conduction losses of the converter.

Power Factor Correction Circuit For Inverter Air-Conditioner Using A Parallel Drive Method (병렬구동 방식을 이용한 인버터 에어컨용 역률제어회로)

  • 정용채;정윤철;권경안
    • Proceedings of the KIPE Conference
    • /
    • 1998.11a
    • /
    • pp.9-12
    • /
    • 1998
  • In this paper, the power factor correction circuit using a parallel drive method is proposed so that the high power inverter air-conditioner with 3[ph] compressor motor may obtain the cost down and the improved performance. The adequate design procedures are presented to reduce the material costs by eliminating the power factor improving LC filter and derating output capacitor and inverter switches. Using the determined components, the prototype circuit with 6[kW] power consumption is built and tested to verify the operation of the proposed circuit.

  • PDF

A Transformerless Cascade Multilevel PWM Rectifier with Unity Power Factor

  • Choi Nam-Sup
    • Proceedings of the KIPE Conference
    • /
    • 2001.10a
    • /
    • pp.576-580
    • /
    • 2001
  • This paper presents a casca multilevel PWM rectifier without the isolation transformers for energy build-up at each inverter modules; The features and advantages of the proposed PWM rectifier can be summarized as follows; 1) It realizes the high power high voltage AC/DC power conversion, 2) It uses no transformer which is bulky and heavy, 3) It has hybrid structure so that switching devices can be effectively utilized, 4) It produces high quality AC current even in high power high voltage applications, 5) The input power factor remains unity by simple modulation index control. The multilevel rectifier is analyzed by using the circuit DQ transformation whereby the characteristics and control equations are obtained. Finally, it will be shown that the system simulation reveals the validity of analyses

  • PDF

A Study on the Optimum Selection of the Power Factor Compensation Condenser According to the Improved Efficiency of Induction Motor (유도전동기 효율향상에 따른 역률 보상 콘덴서 최적 선정에 대한 연구)

  • Kim, Jong-Gyeum
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.65 no.7
    • /
    • pp.1311-1315
    • /
    • 2016
  • Induction motor requires a rotating magnetic field for rotation. Current required to generate the rotating magnetic field is immediately magnetizing current. This magnetizing current is associated with the reactive power. Induction motor is always required reactive power. If reactive power is supplied only to the power supply side, the power factor is low. Therefore, it is to compensate the power factor by connecting capacitors in parallel to the motor terminal. If the capacitor current is greater than the magnetizing current of the motor, there is a possibility that the self-excitation occurs. High voltage generated by the self-excitation leads to insulation failure on the motor. So it is necessary to calculate the power factor correction capacitor capacity the most suitable to the extent that the magnetizing current does not exceed the capacitor current. In this study, we first computed the magnetization current and the reactive power of the induction motor and then calculates a limit of the maximum power factor by comparing the magnetizing current and the capacitor current installed in order to achieve the target power factor.

Design and Implementation of PFC and THD Reduction System for CFL Mulitple Connection (다중접속 CFL용 PFC 및 THD 감소 시스템의 설계 및 구현)

  • 박종연;조호찬;최원호
    • Proceedings of the IEEK Conference
    • /
    • 2002.06e
    • /
    • pp.67-70
    • /
    • 2002
  • In this paper, we have researched a Automatic Power Factor Correction and THD reduction System for the multiple connection of CFL. Also in this paper, the power factor has been researched for the design of CFL, found the reason why the power factor is low and THD is too high. This paper has designed the PFC System for the multiple connection of CFL, and then we have increased the power factor and reduced the total harmonic distortion, by implementing them.

  • PDF

Development of High Voltage and High Energy Density Capacitor for Pulsed Power Application (펄스파워용 고전압 고에너지밀도 커패시터 개발)

  • 이병윤;정진교;이우영;박경엽;이수휘;김영광
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.52 no.5
    • /
    • pp.203-210
    • /
    • 2003
  • This paper describes high voltage and high energy density capacitor developed for pulsed power applications. The rated voltage of the developed capacitor is DC 22 [kV], the capacitance is 206 [$\mu$F] and the energy density is about 0.7 [kJ/kg]. Polypropylene film and kraft paper were used as the dielectrics. The ratio of the thickness of each dielectric material which consists of the composite dielectric structure, stacking factor and the termination method were determined by the charging and discharging tests on model capacitors. In terms of energy density, the developed capacitor has higher energy density compared with the products of foreign leading companies. In addition, it has been proved that the life expectancy can be more over 2000 shots through the charging and discharging test. The voltage reversal factor was 20%. This capacitor can be used as numerous discharge applications such as military, medical, industrial fields.