The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform

Zhen Kang - One of the best experts on this subject based on the ideXlab platform.

  • Zero-Vector-Injection Based Current Sharing Control of Interleaved Full-Bridge LLC Resonant Converters
    Energies, 2020
    Co-Authors: Luo Dejie, Wu Panpan, Xin Zhao, Zhen Kang
    Abstract:

    Interleaved LLC resonant converters are widely used in various fields. However, interleaved LLC converters under Pulse Frequency Modulation (PFM) will lose the regulation of individual phases, causing a load sharing problem. Existing load sharing solutions have limitations; for example, phase shedding and current sharing cannot be realized at the same time. This paper proposed a novel current sharing method for interleaved full-bridge LLC resonant converters. Based on Zero-Vector-Injection, the voltage applied to the resonant tank is controlled to compensate for the difference in gain caused by Component Tolerance. The modulation strategy is proposed to maintain soft switching after Zero-Vector-Injection, and the phase shedding technique is also used to improve the efficiency at a light load. The detailed theoretical analysis and implementation method are proposed and validated using simulations. Experiments are also carried out to verify the feasibility of the proposed strategy based on a 2-phase 1.8 kW prototype.

Jose A. Cobos - One of the best experts on this subject based on the ideXlab platform.

  • A Novel Self-adaptive Wireless Power Transfer System to Cancel the Reactance of the Series Resonant Tank and Deliver More Power
    2019 IEEE Energy Conversion Congress and Exposition (ECCE), 2019
    Co-Authors: Pedro Alou, Jesus A. Oliver, Jose A. Cobos
    Abstract:

    Wireless power transfer (WPT) is a promising technology to supply power in applications where physical contact is not available. Conventionally, both the primary side and the secondary side need resonant capacitor to increase transmission ability. However, the detuning of WPT systems caused by the Component Tolerance of inductors and capacitors and aging of the capacitors will decrease the system performance especially in very low coupling (k=0.05) applications. The delivered power is very sensitive to the reactance under very low coupling conditions, accordingly, a self-adaptive WPT system to cancel the reactance caused by the Tolerance of inductors and capacitors in the primary and secondary is proposed. The novel concept uses an auxiliary circuit in series with the secondary, which can automatically compensate the reactance in the circuit, hence increases the system performance in terms of delivered power. This concept is applicable to both single- and multiple-pickup WPT systems. A prototype has been built and tested experimentally to validate the feasibility of the proposed concept.

Pravee Jai - One of the best experts on this subject based on the ideXlab platform.

  • a robust one cycle controlled full bridge series parallel resonant inverter for a high frequency ac hfac distribution system
    IEEE Transactions on Power Electronics, 2007
    Co-Authors: Joh Lam, Pravee Jai
    Abstract:

    Resonant inverters are connected to a high-frequency AC (HFAC) bus, where power is delivered to different locations for points-of-use power management. Such a power distribution system subjects to more perturbations and load uncertainties than inverters operating with single load. A novel voltage control method is proposed in this paper for a high-frequency full-bridge resonant inverter with series-parallel resonant tank. A modified one-cycle controlled phase-shift modulation is proposed to effectively compensate the input line variations. The uncertainty model of the high frequency resonant inverter is developed and analyzed with the resonant circuit Component Tolerance, input line and load variations taken into design considerations. The voltage feedback controller is designed based on the Hinfin robust control theory and is implemented with analog discrete devices. The proposed control scheme has the advantages of fast response for both input line and load perturbations. It also ensures a wide range of system stability and guarantees robustness of the power converter. Both simulations and experimental results are provided to verify with the theoretical analysis through an experimental prototype of a full-bridge resonant inverter with an output power of 150-W operating at 1 MHz and an output voltage of 28 V (rms).

Luo Dejie - One of the best experts on this subject based on the ideXlab platform.

  • Zero-Vector-Injection Based Current Sharing Control of Interleaved Full-Bridge LLC Resonant Converters
    Energies, 2020
    Co-Authors: Luo Dejie, Wu Panpan, Xin Zhao, Zhen Kang
    Abstract:

    Interleaved LLC resonant converters are widely used in various fields. However, interleaved LLC converters under Pulse Frequency Modulation (PFM) will lose the regulation of individual phases, causing a load sharing problem. Existing load sharing solutions have limitations; for example, phase shedding and current sharing cannot be realized at the same time. This paper proposed a novel current sharing method for interleaved full-bridge LLC resonant converters. Based on Zero-Vector-Injection, the voltage applied to the resonant tank is controlled to compensate for the difference in gain caused by Component Tolerance. The modulation strategy is proposed to maintain soft switching after Zero-Vector-Injection, and the phase shedding technique is also used to improve the efficiency at a light load. The detailed theoretical analysis and implementation method are proposed and validated using simulations. Experiments are also carried out to verify the feasibility of the proposed strategy based on a 2-phase 1.8 kW prototype.

Guangzhong Cao - One of the best experts on this subject based on the ideXlab platform.

  • an active rectifier based maximum efficiency tracking method using an additional measurement coil for wireless power transfer
    IEEE Transactions on Power Electronics, 2018
    Co-Authors: Ruikun Mai, Yeran Liu, Pengfei Yue, Guangzhong Cao
    Abstract:

    The efficiency of wireless power transfer (WPT) systems is highly dependent on the load, which may change in a wide range in field applications. Besides, the detuning of WPT systems caused by the Component Tolerance and aging of inductors and capacitors can also decrease the system efficiency. In order to track the maximum system efficiency under varied loads and detuning conditions in real time, an active single-phase rectifier (ASPR) with an auxiliary measurement coil (AMC) and its corresponding control method are proposed in this paper. Both the equivalent load impedance and the output voltage can be regulated by the ASPR and the inverter, separately. First, the fundamental harmonic analysis model is established to analyze the influence of the load and the detuning on the system efficiency. Second, the soft-switching conditions and the equivalent input impedance of ASPR with different phase shifts and pulse widths are investigated in detail. Then, the analysis of the AMC and the maximum efficiency control strategy are provided in detail. Finally, an 800-W prototype is set up to validate the performance of the proposed method. The experimental results show that with 10% Tolerance of the resonant capacitor in the receiver side, the system efficiency with the proposed approach reaches 91.7% at rated 800-W load and 91.1% at 300-W light load, which has an improvement by 2% and 10% separately compared with the traditional diode rectifier.