The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform

Manlin Chen - One of the best experts on this subject based on the ideXlab platform.

Li Peng - One of the best experts on this subject based on the ideXlab platform.

  • An inrush current mitigation approach of The Output Transformer for inverter
    2015 IEEE Applied Power Electronics Conference and Exposition (APEC), 2015
    Co-Authors: Zhi Chen, Li Peng, Shunchao Wang
    Abstract:

    When a short circuit fault occurs on the load side of inverter, the control system based on hardware and software current limiting strategy can confine Output currents to a certain value. In order to shorten outage time, Output voltages should be restored to rated value as soon as possible after the fault is cleared by the circuit breaker of the faulty branch. However, the voltage recovery may cause significant inrush current phenomenon because of magnetic saturation of the Output Transformer. The high inrush current could lead to voltage distortion and even trigger the protection mechanism. To effectively eliminate the inrush current, this paper proposes an inrush current mitigation approach for three-phase inverter. The phase angle of recovery voltage is controlled so that it is equal to that of fault occurring, which is detected and saved utilizing the double synchronous rotating d-q transformation algorithm. Both simulation and experimental results are provided to demonstrate the feasibility of this method.

  • Feedforward control of Output current for three-phase voltage source inverter (VSI) with Transformer
    2014 IEEE Applied Power Electronics Conference and Exposition - APEC 2014, 2014
    Co-Authors: Yu Qi, Li Peng, Zeyi Huang, Manlin Chen
    Abstract:

    This paper concentrates on the load disturbance in three-phase voltage source inverter with an Output Transformer. The Transformer could be smaller when placed behind the LC filter. But the voltage drop on the leakage impedance of Transformer may destroy the quality of Output voltage. Output current feedforward control is proposed to eliminate the influence of load disturbance. The distinct features of the proposed feedforward control scheme are error-free steady-state fundamental Output and fast dynamic response. Finally, experiment results are given to verify the feasibility and validity of the proposed control strategy.

H. Ikeda - One of the best experts on this subject based on the ideXlab platform.

  • Megasonic transducer drive utilizing MOSFET DC-to-RF inverter with Output power of 600 W at 1 MHz
    IEEE Transactions on Industrial Electronics, 1999
    Co-Authors: T Suzuki, H. Ikeda, H. Yoshida, S. Shinohara
    Abstract:

    This paper describes MOSFET power inverter systems, each provided to drive a megasonic transducer with an Output power of 600 W at a frequency of 1 MHz. Since the megasonic transducer is used as a resonant load with a series resistance of approximately 1 /spl Omega/, the impedance characteristic of the megasonic transducer used as an inverter load is analyzed and compared with measured data. A new method is developed to match the inverter Output impedance to the load impedance of as low as 1 /spl Omega/ at the resonant frequency using a high-performance Output Transformer which can feed RF power to the load at high efficiency. The Output Transformer having a primary-to-secondary winding ratio of 2 to 1 was used by the inverter to drive the megasonic transducer. Based on the analysis of the impedance characteristics of the load, two types of MOSFET dc-to-RF power inverters, a full-bridge version and a single-ended version, were designed and built. These power inverters were put into practical use in cleaners. The power conversion efficiency was greater than 80% for the full-bridge version at an Output of approximately 600 W and 50% for the single-ended version at an Output power of approximately 600 W. When the megasonic transducer was operated with an input power of 600 W. the operation was satisfactory.

  • Control method of PWM inverter for driving LSM to reduce the burden of Output Transformer
    PESC 98 Record. 29th Annual IEEE Power Electronics Specialists Conference (Cat. No.98CH36196), 1998
    Co-Authors: A. Okwi, S. Kaga, H. Ikeda
    Abstract:

    In Japan, a superconducting magnetic levitation (Maglev) system is under development as a means of super high-speed transportation. This system employs a linear synchronous motor (LSM) with the primary side on the ground. The driving power for the LSM is supplied from a power converter installed at a power conversion station on the ground. The power converter should be able to generate power of variable voltage and variable frequency with low harmonics. As a power converter of this type, a multiple pulse width modulation (PWM) inverter is adopted which consists of plural full bridge inverter units with an Output Transformer. However, when the Output frequency is low, it is difficult for the inverter to generate the voltage required, because the inverter is multiplied by the Output Transformer. Therefore, one unit inverter is switched to a half-bridge inverter without an Output Transformer when the Output frequency is low, and the inverter is controlled by a particular voltage assignment control method, instead of a general voltage control method, to reduce the burden of Output Transformer as low as possible. Firstly, this paper describes the voltage assignment control method of the inverter to reduce the burden of Output Transformer. Secondly, the Output voltage is analyzed in detail. Thirdly, the effect of the voltage assignment control and characteristics of Output voltage are investigated. Lastly, these results are verified by simulation.

  • Fullbridged MOS-FET DC-to-RF power inverter for use with high-frequency high-power ultrasonic transducer
    Proceedings of IECON'94 - 20th Annual Conference of IEEE Industrial Electronics, 1994
    Co-Authors: H. Ikeda, Tasuku Nakabori, K. Honda, T. Miyamoto, T Suzuki, T. Yamamoto, S. Sano
    Abstract:

    A full-bridge MOSFET DC-to-RF power inverter consisting of four branches, each branch consisting of three MOSFETs connected in parallel to enhance the power handling capability, was built for driving a high frequency, high power ultrasonic transducer with an Output power of 600 W operating at 1 MHz. When the power inverter was connected to the ultrasonic transducer through an Output Transformer with a primary-to-secondary winding ratio of 2 to 1, the load impedance looking into the load from the inverter was 3.5 ohms at 1 MHz, and was high enough to drive the load with high power conversion efficiency, i.e., over 80%.

  • Fundamental approaches to PWM control based GTO inverters for linear synchronous motor drives
    Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting, 1991
    Co-Authors: S. Tadakuma, S. Tanaka, K. Miura, H. Inokuchi, H. Ikeda
    Abstract:

    High-speed magnetically levitated vehicles require large capacity power converters which supply three-phase sinusoidal current to the armature windings of the linear synchronous motor (LSM). A pulsed width modulated (PWM) inverter using GTOs as a switching device is a promising power converter. Multiplex PWM control has made it possible for inverters to be used for this purpose. A half bridge (HB) and full bridge (FB) are combined with an Output Transformer. A control procedure for reducing voltage harmonics and preventing magnetic saturation of Output Transformers is proposed. A case for neutral point clamped inverters is considered and compared with the HB/FB ones.

P. Enjeti - One of the best experts on this subject based on the ideXlab platform.

  • Multilevel inverter by cascading industrial VSI
    IEEE Transactions on Industrial Electronics, 2002
    Co-Authors: R. Teodorescu, F. Blaabjerg, J.k. Pedersen, E. Cengelci, P. Enjeti
    Abstract:

    In this paper, the modularity concept applied to medium-voltage adjustable speed drives is addressed. First, the single-phase cascaded voltage-source inverter that uses series connection of insulated gate bipolar transistor (IGBT) H-bridge modules with isolated DC buses is presented. Next, a novel three-phase cascaded voltage-source inverter that uses three IGBT triphase inverter modules along with an Output Transformer to obtain a 3-p.u. multilevel Output voltage is introduced. The system yields in high-quality multistep voltage with up to four levels and low dv/dt, balanced operation of the inverter modules, each supplying a third of the motor rated kVA. The concept of using cascaded inverters is further extended to a new modular motor-modular inverter system where the motor winding connections are reconnected into several three-phase groups, either six-lead or 12-lead connection according to the voltage level, each powered by a standard triphase IGBT inverter module. Thus, a high fault tolerance is being achieved and the Output Transformer requirement is eliminated. A staggered space-vector modulation technique applicable to three-phase cascaded voltage-source inverter topologies is also demonstrated. Both computer simulations and experimental tests demonstrate the feasibility of the systems.

  • Cascade industrial VSI gives medium voltage-a case study
    IEE Seminar PWM Medium Voltage Drives (Ref. No. 2000 063), 2000
    Co-Authors: R. Teodorescu, F. Blaabjerg, J.k. Pedersen, E. Cengelci, P. Enjeti
    Abstract:

    In this paper, the modularity concept applied to medium-voltage adjustable speed drives (MV-ASD) is addressed. First, the single-phase cascaded (SC) VSI that uses series connection of IGBT H-bridge modules with isolated DC-buses is presented. Next, a novel triphase cascaded (TC) VSI that uses three IGBT triphase inverter modules along with an Output Transformer to obtain a 3 p.u. multilevel Output voltage is introduced. The system yields a high-quality multistep voltage with up to 4 levels and low dv/dt, balanced operation of the inverter modules that supply each a third of the motor kVA. The concept of using TC-VSI is further extended to a new modular motor-modular inverter (MM-MI) system where the MV motor winding connections are reconnected into several three-phase groups, either six-lead or twelve-lead connection according to the voltage height, each powered by a standard triphase IGBT inverter module. Thus a high fault-tolerance is being achieved and the Output Transformer requirement is eliminated. A staggered space vector modulation (SSVM) technique applicable to triphase cascaded VSI topologies is also demonstrated. Both TC-VSI and MM-MI computer simulations and experimental tests demonstrate the feasibility of the systems.

  • a new medium voltage pwm inverter topology for adjustable speed drives
    IEEE Industry Applications Society Annual Meeting, 1998
    Co-Authors: E. Cengelci, P. Enjeti, S U Sulistijo, Byeong Ok Woo, R Teoderescu, F. Blaabjerg
    Abstract:

    In this paper, a new pulsewidth modulation (PWM) inverter topology suitable for medium-voltage (2300/4160 V) adjustable-speed drive systems is proposed. The modular inverter topology is derived by combining three standard three-phase inverter modules and a 0.33-pu Output Transformer. The Output voltage is high-quality multistep PWM with low dv/dt. Further, the approach also guarantees balanced operation and 100% utilization of each three-phase inverter module over the entire speed range. These features enable the proposed topology to be suitable for powering constant-torque, as well as variable-torque type loads. Clean power utility interface of the proposed inverter system can be achieved via an 18-pulse input Transformer. Analysis, simulation and experimental results are shown to validate the concepts.

Changkun Park - One of the best experts on this subject based on the ideXlab platform.

  • Study of stability problems due to undesired coupling of a RF power amplifier using a distributed active Transformer
    Microelectronics Journal, 2015
    Co-Authors: Jonghoon Park, Changkun Park
    Abstract:

    In this study, we investigate the stability problems induced by undesired coupling between input feed lines and an Output Transformer for a linear CMOS power amplifier using a distributed active Transformer (DAT) as an Output balun. We extracted the losses of the input and Output Transformer, the undesired coupling, and the gains of the driver and the power stages to calculate the closed-loop gain. To determine the possibility of oscillation according to the location of the driver stage related to the undesired coupling and the closed-loop gain, we investigated the stability factor and stability circle. We show that the location of the driver stage of the power amplifier can be used to manage the value of the closed-loop gain. From the analyzed results, the driver stage of the linear power amplifier should be located outside the DAT to mitigate the stability issues.

  • Design methodology for a switching-mode RF CMOS power amplifier with an Output Transformer
    International Journal of Microwave and Wireless Technologies, 2015
    Co-Authors: Changkun Park
    Abstract:

    In this study, we propose a design methodology for a switching-mode RF CMOS power amplifier with an Output Transformer. For a given supply voltage, Output power, and target efficiency, the initial values of the transistor size, Output inductance, and capacitance can be sequentially determined during the design of the power amplifier. The breakdown voltage of the power transistor is considered in the design methodology. To prove the feasibility of the proposed design methodology, we provide the design example of a 2.4-GHz switching-mode CMOS power amplifier with 180-nm RF CMOS technology. From the measured results, the feasibility of the proposed design methodology is proved.

  • CMOS RF power amplifier with reconfigurable Transformer
    Electronics Letters, 2006
    Co-Authors: Changkun Park, S. Hong
    Abstract:

    A CMOS RF power amplifier that can change the Output Transformer ratio is presented. The CMOS power amplifier is fully integrated in a 0.13 /spl mu/m process and has a power added efficiency (PAE) of 38% at 2.1 GHz and an Output power of 30.7 dBm with 3.0 V supply voltage. The PAE at an Output power of 16 dBm was increased by 40% by altering the Transformer ratio.