-
Yoichi Kaya
1995 Volume 115 Issue 8 Pages
957
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
-
Study by NEDO
Nobuyuki Kaya
1995 Volume 115 Issue 8 Pages
958-968
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
-
Tokuo Ohnishi, Masaya Furuhashi
1995 Volume 115 Issue 8 Pages
969-977
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
We propose a new multi-functional single phase PWM inverter for solar power generation system. In this case, it is important to construct the main circuit with simple circuit configuration and control. The proposed single phase inverter with an AC line switch can be constructed only by a three phase inverter module. The functions of the inverter are as follows; 1) an inverter to send the solar cell energy to the utility line, 2) a power line conditioner with an active filter and a reactive power compensator and line voltage controller at the line connecting mode. and 3) an uninterrupted power supply at the line power failer and so on. These are desirable from view points of improving the cost performances of the system.
In this paper, the proposed control circuit and the principle of operation, the control functions and their control characteristics are described. Then some simulation results of the system with many functions are shown. The feasibility of the inverter system are verified by experimental results.
View full abstract
-
Takumi Matsuo, Toshiji Kato
1995 Volume 115 Issue 8 Pages
978-983
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
The series resonant type DC-DC converter with clamped tank capacitor voltage is very effective to reduce the resonant tank voltage and to avoid inverter arm short-through due to diode recovery times. However, the clamping diodes make the operation complex, which is difficult to apply the conventional analytical method. In this paper, a numerical method is applied to investigate the operation. The circuit is found to have 108 topological modes and 32 operation modes. The results are validated through experimental results of a proto-type MOS FET circuit.
View full abstract
-
Tokuo Ohnishi, Yoshikazu Minamoto
1995 Volume 115 Issue 8 Pages
984-990
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
New PWM technique for the current fed type PWM Converter is proposed. As the control variables, the instantaneous active and reactive power are used instead of the line current. They are proportional to the instantaneous active and reactive current vector. The switching state of the PWM converter is given by the selection method of the appropriate current vector among the 7 kinds of the current vectors with the zero current vector. The active current is controlled by the zero current vector and the reactive current depends on the kind of the selected current vector. These variables are basically controlled by PWM switching from two kinds of the hysteresis comparator. In addition to this, the compensation of the filter circuit can be automatically obtained by the PWM control based on the active and reactive current detected from the source current.
In this paper, the principle of the PWM technique for the current source PWM converter is proposed. Then, some simulation results are shown. After that, the feasibility of the system is verified by experimental results.
View full abstract
-
Naoki Oda, Toshiyuki Murakami, Kouhei Ohnishi
1995 Volume 115 Issue 8 Pages
991-998
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
This paper describes a decoupling force control strategy of redundant manipulator by workspace observer. In general, the calculation process of the redundant manipulator becomes complicated as the number of degree-of-freedom motion increases since the controller includes the pseudo inverse Jacobian matrix. To improve this issue, we develop a simplification method of the inverse kinematics solution including null space calculation by using the transposed Jacobian matrix, and the workspace observer. Here the stable condition of the proposed controller is also shown. Its condition is an important index to construct the stable workspace observer.
The validity of the proposed method is confirmed by the numerical and experimental results in the 3link planar redundant manipulator.
View full abstract
-
Bangji Gong, Michio Nakano, Takashi Koga
1995 Volume 115 Issue 8 Pages
999-1005
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
Servo system that is tracking the reference input fastly and finely is demanded in industries. For the realization of this, many control methods using an nonlinear element have been presented. The characteristic of servo system designed by these mothods is improved in contrast to linear ones. But these systems are too sensitive to parameter variation, so the effect of variation must be considered.
To solve this problem we proposed Nominal Model Tracking System. In this method, a robust compensator is designed with H
∞ control theory. As a result, the robust system that is less sensitive to parameter variation is obtained. But since we didn't consider the structure of parameters in the method where all variation is regarded as a single variation of plant's transfer function, the variation that doesn't exist is included. Therefore the scope of robust stability may be narrowed.
In this paper, We discuss Nominal Model Tracking System again with μ-synthesis control theory. Through considering structured variation, we expect that the new system will have robust performance in a wider scope of parameter variation.
As an application, we use the method to the speed control of motor system. From computer simulations, we can show that the method is effective.
View full abstract
-
Tsutomu Yokozuka, Hideomi Sekine, Eiji Baba, Shuaiwen Hu, Takashi Kenm ...
1995 Volume 115 Issue 8 Pages
1006-1014
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
Equivalent circuit parameters are obtained on 19 test motors, whose outputs are in 5.5KW to 6100 hp range of sizes, by which the calculated characteristics such as current, input and slip coincide quite closely with measured ones, and characteristic errors are obtained. Variation of the secondary equivalent circuit parameters with the secondary frequency f
2 is obtained. It is shown that the secondary resistance r
2 increases with f
2 decreases in some motors. Effects of the shape of the rotor slot and magnetic saturation on the secondary circuit parameters are investigated. Effects of the no-load test voltage on the secondary equivalent circuit parameters, and characteristic errors are discussed.
View full abstract
-
Katsumi Kesamaru, Sakutaro Nonaka
1995 Volume 115 Issue 8 Pages
1015-1020
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
This paper proposes two types of new structures for the brushless self-excited single-phase synchronous generator. Both stator and rotor of generator are eqiupped with the concentrated windings. The rotor consists of field winding short-circuited with a diode. These generators are simple and robust, so that the generator can be easily producted. The voltage induced in the field winding by the reverse revolving field due to single-phase armature reaction is half-wave rectified. Then the self-excitation is achieved. The output voltage can be almost kept constant without AVR.
To investigate the characteristics of these generators, the fmite element method, by which the electromagnetic and electric circuit equations are solved directly, is applied. The generator is strictly simulated, taking into account of magnetic saturation and diode's interruption phenpmena. It is confirmed that the results of theoretical analysis agree well with the experimental results.
View full abstract
-
Takeshi Katagi, Junya Matsuki, Takao Okada
1995 Volume 115 Issue 8 Pages
1021-1029
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
With the recent advancement of power elentronics technology, thyristor-controlled equipments have been largely introduced to the electric power system. These devices generate harmonics which cause voltage distortion and undesirable effects on the power system components. On the other hand, the damper windings of synchronous generator are basically designed to reduce harmonics as well as to damp out system oscillations. However, up to now, the effects of damper windings on harmonics have not been fully clarified quantitatively.
In this paper, the results of experimental study on harmonics reduction effect of damper windings have been presented. A specially designed 6kVA generator was connected to an infinite-bus system to investigate the characteristics of damper windings. A new method to measure induced voltages between damper bars, damper bar currents and air-gap flux densities in the tested generator was established. By comparing these measurements with and without the presence of damper windings, the effect of damper windings was quantified. Thus the reduction effects of the damper windings on slot ripples and harmonics caused by armature current mmf were investigated and were made clearer than before by the proposed method.
View full abstract
-
Tsutomu Matsui
1995 Volume 115 Issue 8 Pages
1030-1037
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
This paper presents a high-performance, three-axis lens actuator for high-density disc players, for instance, MUSE (Multiple SubNyquist Sampling Encoding) disc players. The sustained lens position stability at the designed point was improved by inventing a wire-spring suspension system, which has been introduced to gain a high-quality, signal-to-noise ratio (SNR) video signal that equalled 45 dB in baseband Hi-Vision. Compared to the rubber-spring suspension, the wire-spring suspension has better in temperature stability and pull-in servo in the jitter direction. The damping methods invented are double-wire suspension in the jitter direction, gel-box damping in the tracking direction and both methods in the focusing direction.
View full abstract
-
Takayuki Torikai, Yoshikuni Akiyama, Yukihiro Toyoda, Takayoshi Oyama, ...
1995 Volume 115 Issue 8 Pages
1038-1045
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
Diesel engines have been widely used as electrical power sources for small islands and also as mechanical power sources for ships under the isolated circumstances. Therefore, failure diagnosis is of great importance. The paper pays a great attention to the abnormal sealing of exhaust valves, because it occurs frequently and tends to grow into a serious failure.
Based on the data obtained from artificial failure tests using an actual engine, pattern recognition theory was applied to the time series of the longitudinal vibration signal measured by accelerometers on cylinder heads. The paper proposed a method to discriminate between failures in sealing of exhaust valves and in fuel injection timing. Effectiveness of the method was finally verified with experiments.
View full abstract
-
Ken Kato, Yasuhiro Kasuga, Masanori Fujiwara, Kazuo Onda
1995 Volume 115 Issue 8 Pages
1046-1053
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
Laboratory-scale and parametric experiments of SO
2, and NO
x, removal from the simulated combustion gas by pulsed corona discharge have been performed changing the combustion gas composition and temperature, the electrode configuration of plasma reactor and the polarity of high-voltage electrode. The following results are obtained, 1) the higher the concentration of H
2O and O
2, the higher the efficiency of desulfurization and denitrification at the same specific input, 2) the pulsed corona discharge with a voltage pulse-width as short as 200 ns of negative polarity shows the possibility to attain almost 90% deSO
x and de NO
x efficiency at the specific discharge input of 20 J/g, which is almost the same as the specific input in the electron-beam process, 3) the de NO
x characteristics shows a little temperature dependence in the range of 70_??_130°C, but the de SO
x efficiency increases rapidly in the temperature region below 100°C suggesting the thermochemical dependence of deSO
x reaction, 4) when desulfurization and denitrification proceed, the white dendritic powder deposits on the plasma reactor which composition is identified to be 49 mol % of (NH
4)
2SO
4 and 47 mol % of 2NH
4NO
3 • (NH
4)
2SO
4, and the ratio of SO
2, NO and NH
3 of the deposit is almost equal to that of supplied gas.
View full abstract
-
Takesi Sugimoto
1995 Volume 115 Issue 8 Pages
1054-1063
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
Many types of regenerative braked cars are being introduced in dc electric railway for energy saving. Recently specially inverter cars are being placed in service. In East Japan Railway Company inverter control cars (type 209) have their regeneration coefficient mutch increased from about 25% to about 33% as compared with cars (type 205) with superposed field excitation control.
We may expect the regenerative coefficient to be lowered by invalidation on particular sections or particular time zoon, so we must search for the dc feeding system which can level up the regenaration coefficient. On the other hand, recently thyristor rectifier substations are being built to superannuated silicon rectifier substations. We can control the feeding voltage of substation. In the case of inverter cars such as type 209 the author has studied the quantitative effect of saving enegy with many kinds of feeding voltage control system, and demonstrated with simulation the increase in regenerative power and decrease in power consumption without levellig down the acceleration ability of cars.
View full abstract
-
Hayato Oishi, Hidehiko Okada, Kouichi Ishizaka, Ryozo Itoh
1995 Volume 115 Issue 8 Pages
1064-1065
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
-
Hideki Kishimoto, Mitsunao Okumura
1995 Volume 115 Issue 8 Pages
1066-1067
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
-
Hideo Sekimoto, Yasuhiro Nakashima
1995 Volume 115 Issue 8 Pages
1068-1069
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
-
Seiji Hashimoto, Kenzo Kamiyama
1995 Volume 115 Issue 8 Pages
1070-1071
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
-
Masakazu Isogai, Kenzo Kamiyama
1995 Volume 115 Issue 8 Pages
1072-1073
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS
-
Masahiko Akiyama, Kohji Kobayashi, Ichiro Miki
1995 Volume 115 Issue 8 Pages
1074-1075
Published: July 20, 1995
Released on J-STAGE: December 19, 2008
JOURNAL
FREE ACCESS