IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 110 , Issue 5
Showing 1-18 articles out of 18 articles from the selected issue
  • Shinichi Takagawa, Etsuo Nakamura, Shuichiro Hamaguchi, Hiroaki Noda
    1990 Volume 110 Issue 5 Pages 437-446
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
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  • Norikazu Tokunaga, Yasuo Matsuda, Kunio Isiyama, Hisao Amano
    1990 Volume 110 Issue 5 Pages 447-456
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Recently resonant inverter type power supplies for microwave ovens have been examined, but the stability of the filament temperature and the loss of the transformer have not been examined in detail.
    We studied the relation between circuit parameters and the characteristics of the power supply. As a result we conclude that putting a resonant reactor in the primary side of the transformer brings better stability of the magnetron filament temperature and lighter duty of the circuit elements than putting it in the secondary side.
    Newly-developed power supply can be continuously controlled in the range of 5 to 100%. Its efficiency is about 85% which is about 2% higher than that of the conventional one. Moreover the weight is reduced to about 1/4.
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  • Shigeo Masukawa, Yasutomo Moriura, Shoji Iida, Shota Miyairi
    1990 Volume 110 Issue 5 Pages 457-466
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    At present, most of all inverters used in UPS are voltage-source types. In this case, a series reactor is an essential component of the output filter of the inverter because the waveforms of the output voltages consist of trains of voltage pulses. One of major issues of this type of system is magnetic noises, which are produced by the output voltage and appear at the series reactor and the output transformer.
    The use of the current-source inverter has merits not only reducing noises when compared to the case of voltage-source type but also getting a quasi-sinusoidal output voltage without any series reactors. However, there are few cases of applying the current-source inverters to the UPSs because built-in batteries of constant voltage are utilized as a voltage supply in the system.
    The feasibility of applying the current-source inverter to the UPSs is attempted in this paper, and a new circuit topology suitable for the UPSs is proposed. At the output terminal of the inverter only a capacitor is connected in parallel with a load, and the output voltage of the inverter is controlled so as to make it coincide with reference sinusoidal voltage. In order to realize this strategy, two choppers have to be connected between the DC input voltage source and the inverter.
    After showing the circuit configuration, the validity of the proposed method is confirmed by means of both simulation and measurement. When this type of the inverter is applied to an UPS, the waveforms of the inverter output voltage and the switching frequency depend strongly on the circuit constants and output voltage error. Then, these are discussed in quantity to get a design guide. A comparison with conventional current-source inverters shows that the new inverter system has a plenty of merits.
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  • Shoji Iida, Shigeo Masukawa, Junichi Shimomura, Shota Miyairi
    1990 Volume 110 Issue 5 Pages 467-476
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, we propose a new effective method for improving waveforms of output voltages in a double connected voltage source inverter. This method is based on applying two different input DC voltages which change to two levels periodically and differ each other from half cycle in phase, as DC power supplies into the inverter apparatus. The operations of two 6-phase bridge inverter circuits and the configurations of two output transformers, connected delta-delta and delta-star, are exactly the same as the conventional 12-step inverter.
    First is this paper, the principle of the proposed method is described, and the optimum input voltage waveforms are decided theoretically by minimizing the total harmonic distortion factor of the output voltages in this inverter apparatus. Then we suggest that the calculated input voltages with two levels can be realized by dividing those into two DC voltage supplies whose voltage ratio is 2:1 and adding four bi-directional switching elements. Also, the capacities of the DC input sources and the output transformers are calculated.
    As a result, we can make clear that although the construction of the proposed inverter is very simple, the output voltage waveshapes of the inverter are almost the same as those of the 24-step inverter. The experimental discussions are also given.
    Moreover, a voltage control method for applying it to uninterruptible power supply is discussed. In addition, it is shown that the waveforms of output voltage in the inverter apparatus are improved, similar to the conventional 36-step or 48-step inverter when the DC voltage source is divided into 3 or 4 supply parts.
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  • Toshiaki Okuyama, Noboru Fujimoto, Hiroshi Fujii
    1990 Volume 110 Issue 5 Pages 477-486
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A vector control scheme without motor speed and voltage sensors allows high performance speed control of a squirrel-cage induction motor fed by a voltage source PWM inverter, using only a motor primary current sensor.
    A new scheme for simplifying the system configuration by removing the speed and current regulators is proposed. The effects of setting errors in control parameters on speed control accuracy and torque characteristic are analyzed, and it is clarified that the control performance largely depends on stator resistance deviation in the low speed range.
    In order to adapt the control parameter dealing with the stator resistance to the actual value, a parameter adaption method is developed by consideration of a magnetizing current deviation characteristic for the setting error. A design method for the parameter adaption system is also clarified, and its control characteristic and effectiveness are verified by digital simulations and experiments.
    The proposed system is controllable without torque reduction and good speed accuracy, within ±1% from low speed (about 1 Hz), is obtained. This system fits a wide range application and can serve as an alternative to V/f control due to its simple control configuration and good control performance.
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  • Susumu Tadakuma, Shigeru Tanaka, Kazutoshi Miura, Haruo Naitoh
    1990 Volume 110 Issue 5 Pages 487-496
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Vector control techniques of induction motors are based on either the slip frequency control or the field orientation control. As for characteristics, it is well-known that the former is subject to sensitive influences by thermal variations of the secondary resistance while the latter maintains robustness by means of flux detection even if parameters vary. Both methods aim to regulate separately the flux and the torque of induction motors. There is, however, a little difference in the characteristics of the slip frequency type and the field orientation one. The incomplete equivalence between two methods brings about the different properties.
    The slip frequency controlled induction motor does not refer to flux detection or calculation as it is called an indirect method, whereas it suffers the implicit defect that the actual rotating filed is not observed directly.
    The authors propose that a flux oriented torque control be introduced even in the indirect method. This paper describes the new vector controlled induction motors using feed forward and feedback controls.
    The proposed system has a feed forward controller for quick response brought by the existing slip frequency control and a feedback controller for robustness which is provided by the field orientation.
    The feed forward and feedback controlled induction motors are free from degradation in torque generation caused by the thermal variation of the secondary resistance.
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  • Tsugutoshi Ohtani
    1990 Volume 110 Issue 5 Pages 497-505
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Reduction of the motor parameter sensitivity in a vector-controlled induction motor without shaft encoder has been studied using a new method of rotor flux estimator. Usually this system depends on stator parameters, particularly on the stator resistance. In this case, low speed operation is hardly performed, since its method is based on the rotor flux derived from stator voltage and current.
    The proposed rotor flux estimator is constructed with a lag-circuit, the time constant of which is assumed the same value as the rotor-circuit, where the rotor flux command is added to stator voltage and current in order to calculate the rotor flux at standstill. In result, the esimated rotor flux phase error includes no stator resistance component at standstill. Consequently, the proposed system can be performed precisely by the torque-producing current calculated from the estimated rotor flux.
    These features have been verified according to series of experimental results in implementing 30kW-motor and PWM-inverter system. And salient items are summed as follows:
    (1) The torque control was performed independently from the variation of both rotor and stator resistances values practically.
    (2) In the proposed system, both speed and torque controls resulted in good accuracy in a wide speed range of 18 to 1, 800rpm. Also torque was controllable even at standstill.
    It is convinced that the approach solves the problem of high quality torque and speed control using induction motors without shaft encoder.
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  • Shinji Wakui
    1990 Volume 110 Issue 5 Pages 506-515
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In the past, the controller of magnetic bearing was desined only by noticing the stability and robust property. However if the response of displacement by reference signal is implemented, some new industrial applications can be expected. Therefore, in this paper we propose a control method of magnetic bearing, and we especially take account of an improvement of displcement response by using the usual stable controller and the feedforward compensator based on the design method of 2-degree-of-freedom. First, a model of the controlled object is clarified, and the conventional control scheme of magnetic bearing is shown. Second, a practical controller of the magnetic bearing is given with consideration for the effect of the parameter uncertainty and the neglected vibration mode, and some industrial application are proposed. Last, the effective experimental results are shown.
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  • Katsuhiro Izumi, Eiji Yamada, Mineo Tsuji, Jun Oyama
    1990 Volume 110 Issue 5 Pages 516-524
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Several methods have been adopted to identify dynamic performance of controlled system and to determine PID parameters in process control system. However, its application to the field of power electronics is seldom seen. In this case, it is desired to reduce the computation time of the microprocessor.
    This paper proposes an auto-tuning method of DC current control system which is composed of an identification, a conversion method of transfer function and a determination of control parameters. In the system identification by M-sequence signal, we derive new compensation method for the determination of weighting sequence. In the transfer function conversion and the determination of digital control parameters, the formulas without the term depending on time are derived and have few number of product and division. In order to reduce the computation time, all procedures have been developed in assembler language by using the fixed point number. As a result of comparison of the experimental values and simulation ones, it appeared that the compensation method of the weighting sequence was useful and the auto-tuning was done in short computation time.
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  • Katsuhisa Inagaki, Takeshi Furuhashi, Akio Ishiguro, Muneaki Ishida, S ...
    1990 Volume 110 Issue 5 Pages 525-533
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Transformer isolation is a usual practice for ohmic isolation between a source and a load. The transformer designed for commercial frequency (50/60Hz) makes the converter bulky and heavy. Therefore, high-frequency link converters have been studied to make the transformer smaller and to minimize the weight, size and cost of the converters.
    This paper presents a new real-time control method of AC to DC converters with high-frequency links (switch mode rectifiers: SMR's). Results are as follows:
    (1) The new method makes the switching frequency of the SMR smaller than the conventional method.
    (2) The proposed method realizes sinusoidal input current, arbitrary output voltage waveform and controllable input displacement factor. The maximum output voltage ratio to the input liveto-neutral voltage is 3/2.
    (3) The new method is suitable for real time control and suppression of DC magnetization of the high-frequency transformer can easily be implemented.
    (4) Feasibility of the proposed method is confirmed by simulations and experiments.
    Using this method, it is easy to control the voltage waveform of the primary winding of the high-frequency tranformer by changing the output function, so that it is possible to compensate the unbalance of the source voltage and influence of the dead time.
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  • Setsuo Nakamura, Noboru Morita, Takayuki Matsudaira
    1990 Volume 110 Issue 5 Pages 534-541
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Large DC machines are applied to metal rolling mill motors, and their commutation performances are very important to obtain the high responsive operation. But, there is a limit to improve the transient commutation by mechanical reconstruction, because its cause is the lag of commutating flux, at the rapid change of armature current.
    This paper describes the development of intelligential DC machine with the electronic improving equipment of transient and steady-state commutation, that adjusts automatically the most suitable commutation by AI system. The improvement of transient commutation brings the increase of change rate of armature current, so it enables to solve the requirment of control, and the performances of total drive system will be rise up remarkably.
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  • Fang Zheng Peng, Hirofumi Akagi, Akira Nabae
    1990 Volume 110 Issue 5 Pages 542-550
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A combined system of shunt passive and small rated series active filters has already been proposed by the authors. The operating principle and steady compensation characteristics have been presented also. The combined system can greatly reduce problems of using only shunt passive or shunt active filters and is suitable for harmonic compensation for large VA rated loads in power systems, because the required VA rating of the series active filter used here is considerably smaller than that of a conventional shunt active filter.
    In steady states, the combined system behaves like an ideal compensator, because the extraction of the harmonics easy. However, some loads such as cycloconverters fluctuate with rapid speed and cannot be regarded as steady loads. It is difficult for a conventional shunt passive filter to compensate for these fluctuating loads because they generate various frequency harmonics. So it is necessary to discuss transient compensation characteristics of the combined system when it is applied to compensation for fluctuating loads.
    In this paper, focusing on transient states, stability and compensation characteristics of the combined system are analyzed and discussed theoretically and experimentally in detail. The stable and unstable regions of the combined system and the problems faced by improving transient compensation characteristics are revealed. Then, to improve transient characteristics of the system, a new control method is proposed, and the validity is experimentally demonstrated.
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  • Toshihisa Shimizu, Gunji Kimura, Mitsuo Shioya
    1990 Volume 110 Issue 5 Pages 551-560
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In order to improveme the characteristics of high-frequency power supply from an inverter to a resonance load circuit, the authors have been studying a system, consisting of a voltage-fed type inverter, a 1/4 wave-length distributed constant line, and a parallel resonance load circuit, as a new induction heating system. This paper describes a theoretical study performed on the power transmission characteristics of the whole system including the power transmission line, against load fluctuations occurring as conditions of the heated object change.
    Our study has clarified, first, differences as well as problems in characteristics between the case where the inverter operating frequency is kept constant, and the case where inverter operating frequency follows the load resonance frequency. Second, it has been confirmed that power transmission characteristics can be always kept optimum under optimum load conditions, given by improved impedance characteristics of the load circuit against load fluctuations. Finally, we have introduced a new even-number parallel resonance circuit method as a method of approximately reallzing a circuit having such characteristics, analyzed the operating characteristics of this circuit method, and confirmed the usefulness of this method.
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  • Keiji Nakamura, Chobei Yamabe, Kenji Horii
    1990 Volume 110 Issue 5 Pages 561-569
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper describes the characteristics of the vibration of an electric insulator irradiated impulsively by a TEA-CO2 laser beam, and the possibility of the distinction of the cracked sample by detecting the vibration remotely with a He-Ne laser interfeometer. The amplitude of the vibration, monitored by the acceleration sensor touched on the smaple, depends on the laser output energy and the distance between the surface of the sample and the Germanium lens to focus the laser beam on the sample. These characteristics can be explained by the thermal shock by the heating of laser beam, the reaction of the particles spouting from the sample and the shock wave from the air breakdown induced by laser beam in front of the sample, and it is confirmed that the reaction of the spouting particles mainly causes the sample to be vibrated. It is suggested that the cracked sample can be distinguished by estimating the difference of the frequency spectrum or the damping factor of the vibration between the normal and cracked samples, or by listening the output of the photomultiplier of the interferometer through a speaker under the condition that the laser power density is more than 2×107W/cm2 in this experiment. From the above result, it is also suggested that the sample can be vibrated enough to detect the cracked one from the 40m distance by focussing the laser beam which has the TEM00 mode and the energy of 2 J.
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  • Yoshifumi Mochinaga, Yosio Koyama, Takeji Takeuchi
    1990 Volume 110 Issue 5 Pages 570-579
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Auto-transformer feeding system is standard equipment for power supply to high-speed trains and prevention of inductive interference with the telecommunication lines on the AC electrified Shinkansen lines in Japan.
    In the present AT feeding system in which the feeder side of the feeding transformer is not grounded, the insulation level on the feeder side at the substation is set twice as high as the vehicle voltage.
    For the purpose of economizing on the substation power system, the authors have developed new methods adopting a three-winding Scott-connected transformer to make the insulation level on the feeder side a half of the present value and additionally employing a series capacitor with a simplified structure to compensate for the voltage drop.
    This paper describes the structure and characteristics of the three-winding transformer, and insulation level reduction method using it.
    Specifically various features of the system are discussed through simulation of feeding performance by multi-circuit networks analysis and study of various phenomena under use of the series capacitor.
    Furthermore by confirmation tests executed in the Osaka area of the Tokaido Shinkansen line,
    the practical applicability of the system is proved.
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  • Takeshi Mizuma, Hidetoshi Saitoh, Takekazu Amano
    1990 Volume 110 Issue 5 Pages 580-589
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Among linear motor-driven railways, on-board primary linear induction motor-driven railways (steel wheel supported system and levitated system by conducting magnets) have been putting to practical use. This paper refers to electric field strength and magnetic field strength radiated about by these systems. The results are as follows:
    (1) Directly reached radio noise radiated by the linear motor car has the 1_??_2 MHz frequency region at most.
    (2) Radio noise by the linear motor car is similar to that by the VVVF inverter controlled car.
    (3) Magnetic field strength inside the linear motor car is the largest upon the reactor, but is not larger than the ordinary car.
    (4) In the inspection pit, just under the linear motor magnetic field strength is larger, but decreases to safety level at some distances due to the large attennuation. With the above-mentioned founding, the conclusion are as follows.
    (i) Peak envelope detection is the refining method in care of the measurement of electric field strength radiated by electric railways.
    (ii) It is necessary to establish the united standards on the magnetic field strength inside the electric railway cars.
    (iii) The characteristics of electromagnetic field are of little difference between the linear motor cars and the ordinary motor cars.
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  • Atsuo Kawamura, Lazhar Ben-Brahim
    1990 Volume 110 Issue 5 Pages 590-597
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    For a high power induction motor drive, the switching frequency of inverter can not become higher than several kHz, and such switching, frequency produces a large current ripple, which in turn, produces torque ripple. To minimize the current ripple, a new method based on deadbeat control theory for current regulation is proposed. The PWM pattern is determined at every sampling instant based on stator currents measurements, motor speed, current references and rotor flux vector, which is predicted by a full-order observer with adaptive poles selection, so that the stator currents are controlled to be exactly equal to the reference currents at every sampling instant.
    The proposed method consists of two parts: (1) derivation of a deadbeat control; (2) construction of a full-order observer which predicts the rotor flux and the stator currents in the next sampling instant. This paper describes a theoretical analysis and computer simulations under various system conditions.
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  • Mitsunao Okumura, Takaharu Sakai
    1990 Volume 110 Issue 5 Pages 598-599
    Published: May 20, 1990
    Released: December 19, 2008
    JOURNALS FREE ACCESS
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