• 제목/요약/키워드: current-mode transformer

검색결과 128건 처리시간 0.07초

비접촉식 배터리 충전 장치용 Half-Bridge 직렬 공진 컨버터 분석 및 설계 (Analysis and Design of Half-Bridge Resonant Converter for Non-Contact Battery Charger)

  • 김창균;서동현;유정식;박종후;조보형
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제49권4호
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    • pp.265-271
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    • 2000
  • A non-contact battery charger for cellular phone is designed using half-bridge series resonant converter. This converter utilizes series resonance to reduce the undesirable effect of large leakage inductance of the detachable transformer and ZVS operation can reduce switching loss and switching noise. In this paper, analysis and design procedure of half-bridge series resonant converter with detachable transformer is presented. The input voltage is 85VAC∼270VAC, and the output voltage and current is 4.1V and 800mA, respectively. Furthermore, a method of calculating the secondary current of the transformer to control the battery charging current in the constant current charging mode is proposed. The performance of the charger is verified through experiments.

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High-Efficiency CMOS Power Amplifier Using Uneven Bias for Wireless LAN Application

  • Ryu, Namsik;Jung, Jae-Ho;Jeong, Yongchae
    • ETRI Journal
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    • 제34권6호
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    • pp.885-891
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    • 2012
  • This paper proposes a high-efficiency power amplifier (PA) with uneven bias. The proposed amplifier consists of a driver amplifier, power stages of the main amplifier with class AB bias, and an auxiliary amplifier with class C bias. Unlike other CMOS PAs, the amplifier adopts a current-mode transformer-based combiner to reduce the output stage loss and size. As a result, the amplifier can improve the efficiency and reduce the quiescent current. The fully integrated CMOS PA is implemented using the commercial Taiwan Semiconductor Manufacturing Company 0.18-${\mu}m$ RF-CMOS process with a supply voltage of 3.3 V. The measured gain, $P_{1dB}$, and efficiency at $P_{1dB}$ are 29 dB, 28.1 dBm, and 37.9%, respectively. When the PA is tested with 54 Mbps of an 802.11g WLAN orthogonal frequency division multiplexing signal, a 25-dB error vector magnitude compliant output power of 22 dBm and a 21.5% efficiency can be obtained.

A Flyback Transformer linked Soft Switching PWM DC-DC Power Converter using Trapped Energy Recovery Passive Quasi-Resonant Snubbers with an Auxiliary Three-Winding Transformer

  • Ahmed Tarek;Chandhaket Srawouth;Nakaoka Mutsuo;Jung Song Hwa;Lee Hyun-Woo
    • Journal of Power Electronics
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    • 제4권4호
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    • pp.237-245
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    • 2004
  • In this paper, a two-switch high frequency flyback transformer linked zero voltage soft switching PWM DC-DC power converter implemented for distributed DC- feeding power conditioning supplies is proposed and discussed. This switch mode power converter circuit is mainly based on two main active power semiconductor switches and a main flyback high frequency transformer linked DC-DC converter in which, two passive lossless quasi-resonant snubbers with pulse current regeneration loops for energy recovery to the DC supply voltages composed of a three winding auxiliary high frequency pulse transformer, auxiliary capacitors and auxiliary diodes for inductive energy recovery discharge blocking due to snubber capacitors are introduced to achieve zero voltage soft switching from light to full load conditions. It is clarified that the passive resonant snubber-assisted soft switching PWM DC-DC power converter has some advantages such as simple circuit configuration, low cost, simple control scheme, high efficiency and lowered noises due to the soft switching commutation. Its operating principle is also described using each mode equivalent circuit. To determine the optimum resonant snubber circuit parameters, some practical design considerations are discussed and evaluated in this paper. Moreover, through experimentation the practical effectiveness of the proposed soft switching PWM DC-DC power converter using IGBTs is evaluated and compared with a hard switching PWM DC-DC power converter.

변압기 권선진동의 모형화 연구 (A study on the modelling of power transformer winding vibration)

  • 이성호;강창구;김재철;정찬수;곽희로;주병수;윤진열;정상진
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 A
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    • pp.216-218
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    • 1994
  • This paper established on vibration model of transformer winding caused, mainly, by load current. We considered the rotations between loads and vibration amplitudes by changing load current in constant temperature and voltage, to get the modeling of transformer winding vibration. Equation between loads and vibration signal's amplitudes using LS approximation mode it possible to predict a vibration signal's amplitude at any load. With this equation, we arc willing to establish the basis data for power transformer diagnosis.

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3상 유도전동기 구동장치의 동상모드 전류 능동 제거법 (An Active Cancellation Method for the Common Mode Current of the Three-Phase Induction Motor Drives)

  • Uzzaman, Tawfique;Kim, Unghoe;Choi, Woojin
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2019년도 추계학술대회
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    • pp.96-97
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    • 2019
  • Pulse Width Modulation (PWM) is a widely adopted technique to drive the motor using the voltage source inverters. Since they generate high frequency Common Mode (CM) Voltage, a high shaft voltage in induction motor is induced which leads to parasitic capacitive currents causing adverse effects such as premature deterioration of ball bearings and high levels of electromagnetic emissions. This paper presents an Active Cancellation Circuit (ACC) which can significantly reduce the CM voltage hence the common mode current in the three phase induction motor drives. In the proposed method the CM voltage is detected by the capacitors and applied to the frame of the motor to cancel the CM voltage hence the CM current. Unlike the conventional methods the proposed method does not insert the transformer in between the inverter and motor, a high power rating three phase transformer is not required and no losses associated with it. In addition the proposed method is applicable to any kind of PWM motor drives regardless of their PWM methods. The effectiveness of the proposed method is proved by the experiments with a three phase induction motor (1.1kW 415V/60Hz) combined with a three phase voltage source inverter modulated by the Space Vector Modulation (SVM).

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Current Sensorless MPPT Control Method for Dual-Mode PV Module-Type Interleaved Flyback Inverters

  • Lee, June-Hee;Lee, June-Seok;Lee, Kyo-Beum
    • Journal of Power Electronics
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    • 제15권1호
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    • pp.54-64
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    • 2015
  • This paper presents a current sensorless maximum power point tracking (MPPT) control method for dual-mode photovoltaic (PV) module-type interleaved flyback inverters (ILFIs). This system, called the MIC (Module Integrated Converter), has been recently studied in small PV power generation systems. Because the MIC is an inverter connected to one or two PV arrays, the power system is not affected by problems with other inverters. However, since the each PV array requires an inverter, there is a disadvantage that the initial installation cost is increased. To overcome this disadvantage, this paper uses a flyback inverter topology. A flyback inverter topology has an advantage in terms of cost because it uses fewer parts than the other transformer inverter topologies. The MPPT control method is essential in PV power generation systems. For the MPPT control method, expensive dc voltage and current sensors are used in the MIC system. In this paper, a MPPT control method without current sensor where the input current is calculated by a simple equation is proposed. This paper also deals with dual-mode control. Simulations and experiments are carried out to verify the performance and effectiveness of the proposed current sensorless MPPT control method on a 110 [W] prototype.

인버터 시스템과 상용 전력 계통과의 병렬 운전에 관한 연구 (A Study on Parallel Operation Between Inverter System and Utility Line)

  • 천희영;박귀태;유지윤;안호균
    • 대한전기학회논문지
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    • 제41권4호
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    • pp.369-378
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    • 1992
  • This paper proposes a utility parallel processing inverter system, which consists of a voltage source PWM inverter, isolation transformer and a reactor linking the inverter to utility line. This system realizes following functions : (1) voltage phase frequency and amplitude synchronization between inverter and utility line at stand-alone mode. (2) current phase synchronization between inverter and load at parallel mode. Therefore, despite sudden increase in load current over setting point at stand-alone mode, inverter system can be transferred into parallel mode immediately without transient current. Furthermore, high frequency(18KHz) PWM control and sinusoidal filtering improve the inverter output waveform by eliminating high order harmonic components as well as low order. As a switching device, IGBT is used for high frequency switching and large current capacity.

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50 kV, 10kW 소형 고주파 전원장치 변압기 개발 (Development of a Compact 50 kV, 10 kW Transformer for High Frequency Switch Mode)

  • 손윤규;오종석;장성덕;조무현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 F
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    • pp.2027-2029
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    • 1998
  • We have developed a compact high frequency switch mode converter (HFSMC) power supply with DC 50 kV output voltage and 10 kW output power. Since the inverter circuit uses 25 kHz rescharging scheme, the current is flowing with t kHz. For the efficient output voltage transform performed a simple design process using the transformer principle and the commercial specification. For the DC 50 kV output, we employed 7 pa windings of secondary coils for the series stac connection of the output with full-bridge rectifi In this paper the design detail and the test re the high frequency transformer together with HFSMC power supply are presented.

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직류 전철 계통의 정류기용 몰드변압기 안전성에 관한 연구 (The safety Properties of Rectifier Mold Transformer for DC Railway System)

  • 주현정;박현준;김경화
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.742-747
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    • 2005
  • Electric railroad transformer of a supply of Operation power of DC electric cars is intense fluctuation of load and flows the only big short-circuit current as a accident of the power system. it is a peculiarity more severe than general power transformer. Consequently, researches the properties about the rectifier mold transformer of DC substation and applies with data of safety of the electric railroad transformer. This paper analyzed a failure mode, the accident occurrence scenario and the be latent dangerous unit against the rectifier mold transformer of DC railway system.

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Application of an Optical Current Transformer For Measuring High Current

  • Kim, Yeong-Min;Park, Won-Zoo
    • 조명전기설비학회논문지
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    • 제24권11호
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    • pp.9-16
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    • 2010
  • This paper examines the temperature characteristics of an Optical CT (optical current transformer) using the Faraday effect for measuring high current in a super high voltage-power apparatus. It is performed as follows by the sensor for embodying Faraday effect. $\cdot$ A single-mode optical fiber capable of maintaining a polarization state is used. $\cdot$ A light source is applied at 1310[nm] to a Laser Diode. $\cdot$ The Linear of Faraday effect to a large current is evaluated and $\cdot$ A possible application using an Optical CT was shown. An Influence of Faraday effect to the surrounding temperature measured -40~50[$^{\circ}C$], and the characteristic of the current sensitivity was reported. An application using the results of the temperature compensation system was used in order to compensate for surrounding temperatures. A possibility of applying Optical CT for electric power apparatus was advanced further. We were able to confirm that this temperature calibration method can minimize the fluctuation of the output signal depending on the temperature conditions.