電気学会論文誌A(基礎・材料・共通部門誌)
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
128 巻, 8 号
選択された号の論文の12件中1~12を表示しています
Special Issue on Recent Progress in Power Magnetics and Related Technology
Special Issue Review
Special Issue Paper
(Power Devices)
(Motors)
  • Katsubumi Tajima, Tadashi Sato, Yoshinori Sakamoto
    2008 年 128 巻 8 号 p. 527-532
    発行日: 2008/08/01
    公開日: 2008/08/01
    ジャーナル フリー
    A laminated core parametric induction motor has desirable features and the planer structure to make it possible to reduce the production cost of the motor by mass production. In the past work, we showed the validity to apply the two-dimensional reluctance network analytical model to the dynamic analysis of the motor while the rotor is driving. In this paper, we investigate the improvement the accuracy of the analytical method of the motor by using new reluctance network analytical model of the motor. In this model, the magnetic circuits of the stator and the rotor are connected by the variable reluctances that are expressed as the function of the rotating angle.
  • —Inductance Vector Angle based Approach—
    Fuat Kucuk, Hiroki Goto, Hai-Jiao Guo, Osamu Ichinokura
    2008 年 128 巻 8 号 p. 533-538
    発行日: 2008/08/01
    公開日: 2008/08/01
    ジャーナル フリー
    Feedback signals of rotor speed and motor torque are essential in most of Switched Reluctance (SR) motor control applications. An SR motor has highly nonlinear characteristic that does not allow to be modeled by simple equations. In Direct Torque Control (DTC) drive, which enables easy control of torque ripple in the SR motor, position sensor is employed to obtain the feedback signals. Position sensor causes DTC drive not only less reliable but also more expensive. Estimation of feedback signals is required in order to eliminate position sensor. This paper concerns about sensorless speed estimation under the DTC condition and presents a simple method. Simple sensorless speed estimation is proposed based on inductance vector angle. The inductance vector angle is obtained by applying α-β transformation to the phase inductances. A relay triggers a speed calculation circuit according to its band limits and the inductance vector angle. Inside the circuit, triggering time is kept in a memory until the next triggering. Rotor pole pitch is divided by the time difference between two consecutive triggerings. Finally, the estimation circuit outputs the rotor speed. Sensorless speed estimation is simulated and verified experimentally to show its validity.
  • Hiroki Goto, Hai-Jiao Guo, Osamu Ichinokura
    2008 年 128 巻 8 号 p. 539-544
    発行日: 2008/08/01
    公開日: 2008/08/01
    ジャーナル フリー
    Switched Reluctance(SR) motors have several advantages for industrial applications. However, their drive circuits are not necessarily suitable. The drive circuit of a 3-phase SR motor has 6 switches and 6 diodes such as general 3-phase inverter, but its connection is different. So, a general 3-phase power module such as Intelligent Power Module(IPM) can't be used. We proposed a novel drive circuit for SR motors, which can be constructed using general a 3-phase power module without external inductors or devices. This drive method has several advantages including low cost, high efficiency, and compactness. It was simulated on SPICE including the controller and the driving performances were investigated. The new drive circuit allowed phase current to flow bi-directionally. So, the reluctance torque of SR motors is not affected by current direction. Then, we developed the new drive circuit for a 6/4 SR motor using a conventional 3-phase IPM. The results of the experiments indicated same performances as conventional way and higher efficiency than conventional way.
  • Chikara Kaido, Hisashi Mogi, Masahiro Fujikura, Jiro Yamasaki
    2008 年 128 巻 8 号 p. 545-550
    発行日: 2008/08/01
    公開日: 2008/08/01
    ジャーナル フリー
    This paper discusses the deterioration mechanism of magnetic properties of cores due to punching and proposes the modeling, as the best design of motors, considering manufacturing motors, is important in order to improve the high performance of motors corresponding to energy saving. In producing motors, magnetic cores with laminated steel sheets are made of punched sheets, and then the magnetic properties of steel sheets are deteriorated by plastic deformation and the induced residual stress due to punching. In this paper, the punching deterioration mechanism is investigated by observing magnetic domains at steel surfaces near sheared parts. Tensile and compressive stresses induced at cut steel edges deteriorate the magnetic properties of punched steel sheets in high flux densities as the compression deterioration is stronger than the tension improvement, and improve permeabilities at low magnetic field because the increases in permeabilities with tensile stresses are emphasized. Therefore, it is necessary to model the magnetic properties of motor magnetic cores, taking account of these magnetic phenomena.
(Realated Technology)
Special Issue Letter
Paper
  • Hisatoshi Ito, Taichi Ito, Takeo Yamaguchi
    2008 年 128 巻 8 号 p. 559-562
    発行日: 2008/08/01
    公開日: 2008/08/01
    ジャーナル フリー
    An increase in platinum catalyst utilization in polymer electrolyte fuel cells (PEFCs) is necessary to improve performance and reduce costs. We have previously proposed a novel electrode preparation method, based on the process of grafting a proton-conducting agent onto platinum-supported carbon before the conventional electrode fabrication process. In the present study, platinum-supported carbon grafted with methylsulfonic acid groups (-CH2SO3H) and platinum-supported carbon grafted with polyacrylamide tert-butylsulfonic acid groups (Poly-ATBS) were mixed in fabricating the membrane electrode assembly (MEA). The PEFCs' performance of the MEA made from our novel ionomer-grafted platinum-supported carbon material was superior to that of an MEA made using the conventional method using Nafion as an ionomer. The current density at 0.7 V of the MEA using grafted proton-conducting groups on catalyst-supported carbon was 600 mA/cm2, which is twice as large as the MEA using nongrafted catalyst-supported carbon.
feedback
Top