IEEJ Journal of Industry Applications
Online ISSN : 2187-1108
Print ISSN : 2187-1094
ISSN-L : 2187-1094
早期公開論文
早期公開論文の25件中1~25を表示しています
  • Sindisiwe Malanda, Shohei Komeda, Hiroyasu Kifune, Shunsuke Takuma, Yo ...
    論文ID: 24000798
    発行日: 2024年
    [早期公開] 公開日: 2024/06/14
    ジャーナル フリー 早期公開

    In this paper, a control method to realize zero-voltage turn on in the discharging circuit is proposed of a single-phase converter based on a dual-active-bridge (DAB) dc-dc converter with an active energy buffer. The discharging circuit is composed of a buffer capacitor connected in series with a MOSFET switch. The main source of losses in the discharging switch is revealed theoretically through an analysis on the threshold level of the gate signal voltages and their switching timing. A modified gate signal with delay time for the discharging switch is proposed to prevent the parasitic output capacitor from short circuit of MOSFET and flowing inrush current to the DAB converter. Experimental results under 5.4 kW power condition verifies the theoretical assumptions in terms of power losses on each switching devices. As a results, power conversion efficiency with the proposed control method has been improved to 93.5% from the results without the proposed one of 92.9%.

  • Zhaoyang Jin, Keiichiro Kondo
    論文ID: 23013867
    発行日: 2024年
    [早期公開] 公開日: 2024/05/31
    ジャーナル フリー 早期公開

    Cascade H-bridge (CHB) converters show promising potential across various applications, such as power electronic transformers and static synchronous compensator, because of their advantages such as modularity and the ability to generate multilevel output voltage. However, the DC-link voltage of each CHB module needs to be controlled individually. Imbalanced voltage is, therefore, a serious problem for the stable operation of CHB. In this study, we developed a hybrid modulation strategy for a single-phase CHB rectifier (CHBR) in a power electronic transformer used in the traction industry. In the proposed average voltage selected (AVS) method, the average DC-link voltage value is calculated. All modules whose DC-link voltage is lower than the average are charged, and all modules whose voltage is higher than average are discharged. Furthermore, a duty ratio saturation compensation is used. Compared with previous hybrid modulation strategy with a wide stable operation region, the AVS method can decrease the input current total harmonic distortion (THD) and DC-link voltage THD without sacrificing the stable operation region and switching loss. The effectiveness of the AVS method was verified by simulation and experiments.

  • Md Roknuzzaman, Shin-ichi Hamasaki
    論文ID: 23007255
    発行日: 2024年
    [早期公開] 公開日: 2024/05/24
    ジャーナル フリー 早期公開

    This paper intensively discusses control of the transformer-less hexagonal modular multilevel converter (HMMC). The HMMC is applied as a loop power controller (LPC) for a three-phase power system in which the ends of two power feeders are connected to form a power loop. The LPC is an attractive power system that enables changing the power flow balance between two feeders to avoid exceeding the current capacity. HMMC is a modular multi-level converter (MMC) topology, and has extensive ability for multilevel output voltage. MMC represents an emerging topology for three-phase BTB applications such as wind turbine generation systems, STATCOM, etc. The transformer-less configuration of MMC facilitates weight and size reduction of the converter, but the capacitor voltages in cell modules need to be regulated properly. This paper proposes a control scheme based on the current control of HMMC for LPC applications, which includes active and reactive power control, capacitor voltage control, and some related controls. This article describes the current flow control between two feeders; the three-phase load on each feeder is connected to HMMC. Especially, in order to maintain constant capacitor voltages, a combined circulating current control strategy including independent circulating current control for the primary and secondary sides and an internal circulating current control is proposed. This method is effective for operation under different phases between two feeders or three-phase unbalanced load for LPC applications. Further, simulations and experiments in typical cases verify the feasibility and effectiveness of the proposed control strategies.

  • Keisuke Matsumura, Aozora Hata, Hirokazu Matsumoto, Yuki Sato
    論文ID: 23007801
    発行日: 2024年
    [早期公開] 公開日: 2024/05/24
    ジャーナル フリー 早期公開

    This study introduces an optimal system combining a circuit configuration and control algorithm for wireless power transmitter with coils arranged in a square pattern. The system uses a four-leg half-bridge inverter to simultaneously feed power to four coils through a switch set. Inductances, including the mutual inductances between the transmitter coils, are eliminated using the reactance devices on the return path in the proposed circuit configuration. The proposed control algorithm enables uniform power transfer at maximum efficiency, independent of the receiver position. The experimental results obtained using a prototype of the transmitter confirm that the system can transfer 500 W with a slight variation of 5.56% and efficiencies more than 80.6%.

  • Takuya Shiohara, Yoshihiro Maeda
    論文ID: 23013778
    発行日: 2024年
    [早期公開] 公開日: 2024/05/24
    ジャーナル フリー 早期公開

    This paper presents a practical and high-performance auto-tuning method for feedback controllers in industrial servo systems aimed at achieving fast and precise positioning. Conventional auto-tuning approaches generally limit control performance by avoiding an aggressive parameter search for fear of instability of the FB control system during auto-tuning. To overcome this issue, the proposed method employs a stable parameter search space that ensures specified stability margins and searches for optimal parameters within this space. The proposed method is established by combining it with a genetic algorithm-based parameter search as an example global optimization-based auto-tuning method, and is adopted for fast and precise positioning control of a galvano scanner. The results of auto-tuning experiments demonstrate the effectiveness of the proposed method compared to a conventional auto-tuning method that does not consider a stable parameter space.

  • Masataka Minami, Ryugo Kurita, Tenshin Kamahara, Keisuke Fujisaki
    論文ID: L24000314
    発行日: 2024年
    [早期公開] 公開日: 2024/05/24
    ジャーナル フリー 早期公開

    High-speed switching with wide bandgap semiconductor switches is increasingly being applied to motor drive sys- tems in electric vehicles. However, the MHz ringing phenomenon caused by high-speed switching leads to an increase in losses in magnetic materials of the motors. This letter proposes a low-pass filter (LPF) to suppress the MHz ringing phenomenon. And, it demonstrates that the use of the proposed LPF results in the reduction of iron and copper losses.

  • Toshiyuki Fujita, Kodai Takeda, Takehiro Imura, Takafumi Koseki, Yusuk ...
    論文ID: 23011368
    発行日: 2024年
    [早期公開] 公開日: 2024/05/10
    ジャーナル フリー 早期公開

    Wireless power transfer (WPT) system for electric vehicles is expected for different manufacturers to construct the transmitting and receiving sides. This paper proposes a reference impedance plane method for interoperability by independently calculating the transmitting and receiving sides and comparing the regions where power transfer is possible. The proposed method also accommodates various constraints and self-inductance variations of the misalignment. A 6.6-kW rated WPT system was designed and constructed to demonstrate the effectiveness of the proposed method and confirm the power transferability and adherence to the constraint conditions.

  • Kenshi Matsuo
    論文ID: L23001188
    発行日: 2024年
    [早期公開] 公開日: 2024/05/10
    ジャーナル フリー 早期公開

    Stepping motors experience oscillation when positioning. A proposed sensorless tuning method for back-phasing damping can determine the appropriate excitation times to suppress the oscillation numerically according to added inertial load conditions after the motor model is estimated from the winding voltage. The driving experiments demonstrate suppression using the excitation times tuned for added loads.

  • Kazuho Igarashi, Ryo Igarashi, Takenori Atsumi, Shigeyuki Nakadai
    論文ID: 23008418
    発行日: 2024年
    [早期公開] 公開日: 2024/05/03
    ジャーナル フリー 早期公開

    This study presents a feedforward control method that reduces the seek time of hard disk drives (HDDs) using a sampled-data polynomial based on a causal first-order hold (CFOH). The method improves the seek time of the magnetic-head positioning control system of the HDDs, primarily because the CFOH responds faster than the conventional zero-order hold (ZOH). The sampled-data polynomial enables easy and real-time calculation of the feedforward control input using polynomials, eliminating the need for memory-consuming lookup tables. The sampled-data polynomial for CFOH meets the boundary conditions, including the CFOH characteristics. Moreover, it effectively corrects the discretization error caused by the CFOH without complex calculations. Replacing the ZOH with the CFOH in the feedforward control system of the HDDs improves the performance significantly. Simulation results of the track seeking control of the HDDs confirm that the proposed method successfully reduces the seek time compared to a conventional method.

  • Guiyi Dong, Tomokazu Mishima, Hideki Omori, Ching-Ming Lai
    論文ID: 23011032
    発行日: 2024年
    [早期公開] 公開日: 2024/05/03
    ジャーナル フリー 早期公開

    This paper presents a new prototype of a single-phase class-E direct ac-ac converter for induction heating applications. In contrast to the multi-stage and traditional single-stage power conversion systems, the proposed direct ac-ac converter not only simplifies the topology of power conversion, but also enhances the efficiency, soft-switching, and EMI performance, optimizing the overall system performance. This converter features a power control methodology utilizing the reverse conducting and reverse blocking modes of a bidirectional switch based on pulse density modulation, which is suitable for a wide range of soft switching and fixed frequency operations. The performance of the direct ac-ac converter is investigated by experiments using a 1.2 kW/56 kHz prototype, where the high-frequency load power regulation and power conversion efficiency are revealed as well as soft switching were verified. The practical effectiveness of the power converter and power control scheme are evaluated.

  • Takahiro Mizuta, Kazumasa Ito, Toshinori Tanaka
    論文ID: 23002114
    発行日: 2024年
    [早期公開] 公開日: 2024/04/05
    ジャーナル フリー 早期公開

    In high-speed surface permanent-magnet motors, eddy current loss in the rotor caused by magnetic flux harmonics is a significant problem. Although copper sleeves can reduce the eddy current loss of the rotor, the reduction effect on each eddy current harmonic component is not clear. In this paper, we calculate the eddy current loss in the rotor using finite element analysis, divide the losses into each harmonic magnetic flux component, and analyze the influence of copper sleeve on each harmonic component. Based on the knowledge obtained in the analysis, we propose the use of copper sleeve with holes as a method for reducing rotor loss further. The effect of the proposed method is verified using electromagnetic simulation.

  • Akira Heya, Yoshihiro Nakata, Tetsuya Abe, Katsuhiro Hirata
    論文ID: 23010457
    発行日: 2024年
    [早期公開] 公開日: 2024/04/05
    ジャーナル フリー 早期公開

    This paper presents the disturbance response and sensor-less force control of a magnetic lead screw actuator (MLSA) that generates linear motion; it is composed of a magnetic lead screw and a rotary motor. This MLSA exhibits elasticity owing to magnetic spring properties, and it can respond flexibly against disturbances. The implemented magnetic lead screw has a spiral structure composed of arc shape permanent magnets and soft iron teeth instead of a spiral shape permanent magnet. This design advantageously reduces the number of parts and simplifies assembly. In the experiment, both the MLSA and a ball screw actuator undergo forced oscillation induced by a load actuator. Each actuator is controlled to maintain the zero contact force. The root mean squared error of the MLSA was found to be smaller than that of the ball screw actuator, demonstrating superior disturbance response of the MLSA. In addition, the effectiveness of the sensor-less force control method focused on a magnetic phase difference was verified through modeling of thrust and friction characteristics in the experimental results. Control experiments indicate that the MLSA can regulate force without the need for a force sensor.

  • Akihiro Katsuno, Toshiyuki Murakami
    論文ID: 24001384
    発行日: 2024年
    [早期公開] 公開日: 2024/04/05
    ジャーナル フリー 早期公開

    This study developed a two-dimensional heat path topology optimization method that minimizes the peak temperature inside motor slots. By representing the coil and varnish as a homogenized material, the problem was simplified to a two-phase topology optimization of the homogenized material and heat conductor. The motor performance was represented as a constraint on the magnetomotive force, which is related to the heating rate of the windings. Because the heating rate depends on the winding occupancy, we developed a new formulation for the sensitivity of the objective function. The heat path geometry was optimized without volume limitation under the trade-off relationship between the heat transfer efficiency and heat generation rate. The results indicated an 8.84% reduction in the peak temperature of a motor slot compared to that of a conventional simple aluminum plate.

  • Shogo Nakahara, Satoshi Nagai, Makoto Ochiai, Yoshitaka Muguruma, Shin ...
    論文ID: 23000528
    発行日: 2024年
    [早期公開] 公開日: 2024/03/29
    ジャーナル フリー 早期公開

    This paper proposes a zero-voltage switching (ZVS) scheme for a dual active bridge (DAB) converter in the full load range. The switching state of the DAB converter with a phase-shift control becomes a hard switching state under an input and output voltage imbalance or light load. Thus, the proposed method regulates the phase-shift angle, out- put voltage angle of full-bridge circuits, and switching frequency to achieve ZVS for the DAB converter. The DAB converter implementing the proposed ZVS scheme is applied to vehicle-to-home (V2H) systems. Experimental results reveal that a V2H unit using the DAB converter achieves an efficiency 97.2% with the proposed ZVS scheme.

  • Shota Seki, Tsuyoshi Funaki
    論文ID: 23013822
    発行日: 2024年
    [早期公開] 公開日: 2024/03/29
    ジャーナル フリー 早期公開

    High-switching frequency power converters are used in wireless power transmission and material processing. Soft-switching technique is crucial to reduce switching loss in high-frequency operation, e.g. ISM(Industrial Scientific and Medical) bands such as 13.56 MHz and 27.12MHz. Recently, GaN power devices are expected to realize high-frequency operation of a power converter. The voltage dependency of the output capacitance in GaN power device exhibits highly nonlinear characteristics, making the analysis and design of the power converter difficult. This paper proposes to apply the sigmoid function to model the voltage dependency of the output capacitance in a GaN power device. The design of the class-E amplifier using the proposed model is presented. Circuit simulations with device model and experiments demonstrate class-E switching operation.

  • Shoki Nakagoshi, Yuki Hidaka
    論文ID: 23013971
    発行日: 2024年
    [早期公開] 公開日: 2024/03/29
    ジャーナル フリー 早期公開

    This paper presents a novel rotor structure for spoke-type interior permanent magnet motors. In the proposed motor, the rotor is fastened to the shaft using a resin unit. Thus, the inner-side core, which is the leakage path for the magnetic flux, can be eliminated. As a result, the torque density of the proposed motor can be improved compared with that of conventional motors without increasing the magnet volume. A numerical verification was performed using the finite element method to validate the effectiveness of the proposed structure. Moreover, the proposed structure was experimentally verified using a prototype motor. The results of numerical and experimental verifications indicate that the proposed structure could improve the torque density without increasing the magnet volume.

  • Takachika Hatano, Daiki Satou, Ryosuke Ota, Ryohei Okada, Hiroyasu Kob ...
    論文ID: L23000934
    発行日: 2024年
    [早期公開] 公開日: 2024/03/29
    ジャーナル フリー 早期公開

    This paper proposes a phase-synchronization method for double-sided LCC wireless power transfer systems with active rectifiers, achieved by using a current detector. The detector can be constructed inexpensively by simply adding a winding to the compensation inductor. Furthermore, the detector provides voltage step-down and isolation functions. Experimental results confirmed that the proposed method successfully synchronizes the primary and secondary systems across a wide range of coupling states for the transmission coils, with a coupling factor 𝑘 ranging from 0.05 to 0.3.

  • Naoto Fujishima
    論文ID: 23005497
    発行日: 2024年
    [早期公開] 公開日: 2024/03/15
    ジャーナル フリー 早期公開

    Power electronics technologies play important roles in energy conservation and low-carbon goals, whereby power devices, such as silicon IGBTs and SiC-MOSFETs, are key components that support the efficient use of energy by power electronics and are indispensable for power supply and control. This paper provides an overview of market trends for power semiconductor devices, and introduces and focuses on state-of-the-art SiC power devices, such as SiC-MOSFET and SiC-SBD. This paper also reports on the requirements and applications of power electronics equipment that utilizes SiC power devices.

  • Min Zou, Kota Matsunaga, Yuji Ueda, Tsuyoshi Sugawara, Hideyo Osanai, ...
    論文ID: 23006878
    発行日: 2024年
    [早期公開] 公開日: 2024/03/15
    ジャーナル フリー 早期公開

    Automatic detection of defects in a substrate is important in the manufacturing process. Defect detection in metalceramic substrates relies on manual assembly lines, which are laborious and time consuming. This study develops a novel defect detection method that automatically localizes the substrate area without a background and enhances the defect area by combining images acquired using a platform with different illumination patterns. In this study, we use a defect image dataset to train convolutional neural networks (CNNs) for defect discrimination. Seven evaluation metrics, i.e., accuracy, F1-score, area under the curve, and prediction time of all the patch images in the test set, are comprehensively considered to select the optimal parameter configuration. A developed ResNet-50-based model achieves the highest defect discrimination accuracy of 99.8%. Based on extensive experiments and their results, this study provides clear guidance for devising a feature extraction method based on multidirection filter processing and optimization of CNNs for classification tasks. Finally, a framework for defect detection in a metal-ceramic substrate for practical use in the power device industry is developed.

  • Yasuhiko Neba, Takeshi Ohno, Shintaro Kusuki
    論文ID: 23012420
    発行日: 2024年
    [早期公開] 公開日: 2024/03/15
    ジャーナル フリー 早期公開

    A dual current source inverter for an induction motor drive is presented in this paper. The dual inverter consists of two inverters connected in parallel and has single a dc power source. The inverters are operated using the same pulse width modulation (PWM) pattern, with one of the patterns being phase-shifted to the other. Each inverter supplies the torque current and the exciting current to the motor, respectively. The control strategies for constant voltage, constant exciting current, and slip frequency are demonstrated for the motor drives. The experimental results of the dual inverter are compared with those of the conventional single inverter in the steady-state and transient operation. The experiments show that, in the steady-state, the dual inverter system has the same motor characteristics as the single inverter system. The dual inverter can regulate not only the amplitude but also the phase of the output current, depending on the motor condition. The results from the transient operation demonstrate that the motor driven by the dual inverter can rapidly produce the desired torque and has good performance with fast response.

  • Atsuo Kawamura, Yukinori Tsuruta, Hidemine Obara
    論文ID: 23013265
    発行日: 2024年
    [早期公開] 公開日: 2024/03/15
    ジャーナル フリー 早期公開

    This paper is a re-evaluation of a completed project (High Efficiency Demonstration Grant Using High Voltage SiC Device) from the perspective of accurate efficiency measurement; additionally, this paper discusses on device dv/dt estimation. A topology called the high-efficiency energy conversion system (HEECS), which is one variety of partial boost circuit topologies, is introduced to achieve efficiency over 99.5%. The topology exhibits a very high efficiency for applications in which the output voltage variation is within a certain ratio of the rated output voltage. This paper summarizes the basic features of the topology and theoretically derives the principle of high-efficiency realization. The high efficiency is measured by the back-to-back(BTB) connection of two converters, and the efficiency and accuracy on this method are theoretically derived and confirmed using the measured data of 3.3 kV output voltage at 100 kW output. The theoretical estimation of dv/dt for a 3.3 kV SiC device to reduce dual-active-bridge(DAB) soft-switching loss is discussed. Furthermore, a trend of DC-DC conversion efficiency is shown, and we show that the partial boost topology is a promising approach for achieving high efficiency dc-dc conversion.

  • Shigeo Morimoto, Yuki Shimizu, Yukinori Inoue, Masayuki Sanada
    論文ID: 23009975
    発行日: 2024年
    [早期公開] 公開日: 2024/03/08
    ジャーナル フリー 早期公開

    Maximum torque per ampere (MTPA) control is a typical control method for achieving a high-efficiency operation for interior permanent magnet synchronous motors (IPMSMs). However, inductances of IPMSMs with magnetic saturation, vary depending on the current; thus, obtaining the MTPA condition is difficult. This study developed an online MTPA angle search method for IPMSMs with cross-saturation. In the proposed method, a flux-linkage plane is modeled and the model parameters are identified using the recursive least squares (RLS) method. The proposed method searches for the optimum current phase angle (MTPA angle) achieving MTPA control based on the gradient ascent method using the parameters identified for the flux-linkage plane model. This study conducted various experiments to evaluate the performance of the proposed online MTPA angle search method. The effectiveness of the method was demonstrated.

  • Sora Nagao, Yusuke Kawai, Yuki Yokokura, Kiyoshi Ohishi, Toshimasa Miy ...
    論文ID: 23008684
    発行日: 2024年
    [早期公開] 公開日: 2024/03/01
    ジャーナル フリー 早期公開

    The feedback of load-side acceleration is an effective method in the control of a two-inertia system. The load-side acceleration is generally obtained using an acceleration sensor. However, the bias drift of the sensor poses problems. Under an acceleration sensor bias, the velocity response experiences drift phenomena caused by sensor bias. In this paper, an observer that estimates the bias of the load-side acceleration sensor is designed. The proposed observer is evaluated using proportional velocity control. As an application, the proposed observer was applied to the load-side acceleration control, and it compensated for the effect of the acceleration sensor bias. Its effectiveness was verified through simulations and experiments.

  • Akira Kumashiro, Yusuke Fujii, Akira Chiba, Wolfgang Gruber, Gerald Ju ...
    論文ID: 23008015
    発行日: 2024年
    [早期公開] 公開日: 2024/02/16
    ジャーナル フリー 早期公開

    Magnetic-geared motors have many advantages over mechanical gearboxes, such as reduced maintenance and overload protection. However, the limited life of the mechanical bearings, which hold a high-speed rotor, is problematic in terms of durability. In this paper, a magnetic-geared motor with an integrated bearingless high-speed rotor having a novel structure is proposed to solve this problem. The proposed magnetic-geared motor has an additional three-phase winding to achieve magnetic suspension for the high-speed rotor. In addition, the proposed structure has a consequent-pole high-speed rotor for simplified suspension control, and it can reduce the number of sensors. This paper presents the principles of magnetic suspension and torque generation. In addition, a comparison of the magnetic suspension characteristics and torque capabilities of different motor topologies determined by finite element analysis is discussed.

  • Ryosuke Shibuya, Toshiaki Tsuji
    論文ID: 23007663
    発行日: 2023年
    [早期公開] 公開日: 2023/12/15
    ジャーナル フリー 早期公開

    Estimating human stiffness is crucial for achieving precise robotic manipulation through variable impedance control. For in order to enable a robot to replicate human-like stiffness, it is essential to have a comprehensive understanding of the stiffness characteristics exhibited by humans during different tasks. Consequently, the development of an estimation method becomes imperative. One significant challenge in estimating human stiffness is to accurately assess armstiffness when it is in contact with a highly rigid environment. Therefore, this study aimed to devise a method to estimate the stiffness of the human arm during contact with such environments. The proposed approach involves an equation for estimating arm stiffness using force information obtained from the human hand.

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