IEICE Electronics Express
Online ISSN : 1349-2543
ISSN-L : 1349-2543
Volume 19, Issue 20
Displaying 1-5 of 5 articles from this issue
LETTER
  • Subramaniyan Geethanjali, Krishnasamy Vijayakumar
    Article type: LETTER
    Subject area: Power devices and circuits
    2022 Volume 19 Issue 20 Pages 20220343
    Published: October 25, 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 21, 2022
    JOURNAL FREE ACCESS

    Escalating fuel prices and a keen attention to improve air quality have resulted in proliferation of pure electric and hybrid electric vehicles. Fuel savings and reduced carbon footprint are the main enablers for the choice of electric automobiles compared to the conventional vehicles with internal combustion engines. Availability of electric power sources such as lightweight battery packs also has promoted electric drive as a viable option. Both plug-in electric and hybrid vehicles necessitate new power train schemes ensuring safe and reliable operation. The DC-DC converters are the heart of an electric vehicle. They are used to convert the battery voltage to another level as required by the motor drive. Traditionally, most of the automakers use buck boost converter as it enables the bidirectional operation. This paper presents a comprehensive analysis of a dual way DC-DC converter namely split pi converter for an electric vehicle drive train system driving an inverter fed induction motor. The dual way converter investigated has numerous advantages such as inherent bidirectional capability, EMI reduction and reduction of the passive elements. Simulation results and experimental investigations based on a laboratory prototype are presented.

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  • Xiaolei Shi, Yipeng Lan
    Article type: LETTER
    Subject area: Power devices and circuits
    2022 Volume 19 Issue 20 Pages 20220375
    Published: October 25, 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 21, 2022
    JOURNAL FREE ACCESS

    This paper proposes an improved predictive position control (IPPC) method based on the disturbance observer (DOB) for linear synchronous motor (LSM) to enhance the tracking accuracy and robustness against parameter mismatches and load disturbance. A soft constraint containing the difference between predictive tracking errors and their exponential convergence trajectory is developed to the cost function to improve the tracking accuracy. Moreover, the IPPC employs a variable exponential-based DOB to estimate disturbances to improve the system’s robustness to parameter mismatches and load disturbance. The control system’s stability is analyzed using the Lyapunov stability theory and Bellman’s principle of optimality. The experimental results show the effectiveness of the control scheme.

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  • Shuo Zhang, Shunxi Lou, Wei Wang, Yuanchen Zeng, Xiang Gao
    Article type: LETTER
    Subject area: Electromagnetic theory
    2022 Volume 19 Issue 20 Pages 20220396
    Published: October 25, 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 16, 2022
    JOURNAL FREE ACCESS

    An analytical model is proposed to calculate the performance on beam collecting efficiency (BCE) of transmitting arrays with excitation errors for microwave power transmission (MPT). Due to the inconsistent output of power amplifiers and the uncertainty of the joint loss of radio frequency (RF) device, the small perturbations will be brought into excitation amplitudes and phases, which will decrease the BCE. This analytical model involves the use of a Taylor series expansion to account for small perturbations in the excitation errors. The mathematical model between the statistical information of excitation perturbations and BCE is directly established. To fully prove the accuracy of the given model, numerous random samples will be used to compare the results of the proposed model and Monte Carlo simulation (MCS). Compared with the MCS, the proposed model does not require much-repeated calculation. The proposed method can be applied at the antenna design stage to effectively evaluate the effect of excitation perturbations on the BCE.

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  • Guihua Zhao, Xing Jin, Huafeng Ye, Yating Peng, Wei Liu, Ningyuan Yin, ...
    Article type: LETTER
    Subject area: Electromagnetic theoryCircuits and modules
    2022 Volume 19 Issue 20 Pages 20220399
    Published: October 25, 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 20, 2022
    JOURNAL FREE ACCESS

    In-memory computing (IMC) quantized neural network (QNN) accelerators are extensively used to improve energy-efficiency. However, ternary neural network (TNN) accelerators with bitwise operations in nonvolatile memory are lacked. In addition, specific accelerators are generally used for a single algorithm with limited applications. In this report, a multiply-and-accumulate (MAC) circuit based on ternary spin-torque transfer magnetic random access memory (STT-MRAM) is proposed, which allows writing, reading, and multiplying operations in memory and accumulations near memory. The design is a promising scheme to implement hybrid binary and ternary neural network accelerators.

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  • Chao Fu, Tianwei He, Wenrao Fang, Wenhua Huang, Ruyu Fan, Lulu Wang, Y ...
    Article type: LETTER
    Subject area: Microwave and millimeter wave devices, circuits, and modules
    2022 Volume 19 Issue 20 Pages 20220407
    Published: October 25, 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 21, 2022
    JOURNAL FREE ACCESS

    This letter proposed a new Wilkinson power combiner/divider (PCD) with enhanced average power-handling capability (APHC) by decreasing the impedance of the microstrip of the combine port. For verification, one example of the proposed Wilkinson PCD operating at 2.3GHz was designed, fabricated and measured to verify the proposed theory. One traditional Wilkinson PCD operating at 2.3GHz was also fabricated to compare the APHC of the proposed Wilkinson PCD and the traditional Wilkinson PCD, by means of measuring the temperature variation of the microstrip line at the same input power. The measurement result of the temperature variation suggests the APHC of the proposed Wilkinson PCD is nearly twice that of the traditional Wilkinson PCD.

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