Showing papers in "Electrical Engineering in Japan in 2001"
TL;DR: In this article, the design of the single-sided linear induction motor (SLIM) propulsion and wheel-on-rail support and guidance was formulated as a constrained nonlinear programming problem, and optimum design was carried out to maximize efficiency.
Abstract: Linear metro with single-sided linear induction motor (SLIM) propulsion and wheel-on-rail support and guidance came into service in April 1990 in Osaka and in December 1991 in Tokyo, and is under construction or planned for Yokohama, Kobe, and Fukuoka. Since the new traffic system is used widely, it is of great importance to decrease its energy consumption.
In this paper, the design of the SLIM for the linear metro is formulated as a constrained nonlinear programming problem, and optimum design is carried out to maximize efficiency. Seven parameters are chosen as independent variables: number of poles, pole pitch, stack height, secondary aluminum sheet thickness, overhang length, slot width/slot pitch ratio, and rated slip. The output KW/input KVA ratio, maximum flux density in teeth, temperature rise, primary length, stack height, overhang length, maximum thrust, and vertical force are selected as constraint functions.
In the optimization procedure, the performance characteristics are formulated by space harmonic analysis taking account of the end effect, skin effect, and air gap leakage. The accuracy of the formulas is verified against experimental results.
Effective ways of increasing efficiency include the addition of a copper reaction plate and minimization of the mechanical clearance. © 2001 Scripta Technica, Electr Eng Jpn, 137(2): 36–43, 2001
49 citations
TL;DR: It is shown that effective estimation of the optimal slip ratio is difficult to perform by the simple gradient method, which is a well‐known optimization method, but various experimentally obtained data can be easily incorporated into fuzzy inference, and therefore its estimation performance can be easy improved by the accumulation of human experience.
Abstract: In this paper we propose an optimal slip ratio estimation method based on fuzzy inference. One of the major advantages of electric vehicles is the quick and precise torque response of the electric motor, which realizes a novel traction control system. To prevent skidding, optimal slip ratio control has been successfully developed. It maintains the slip ratio at the optimum value that gives the maximum driving force. The remaining problem is how to generate the optimal slip ratio command sent to the controller. First we show that effective estimation of the optimal slip ratio is difficult to perform by the simple gradient method, which is a well-known optimization method. But various experimentally obtained data can be easily incorporated into fuzzy inference, and therefore its estimation performance can be easily improved by the accumulation of human experience. This is a major advantage in the nonlinear estimation of real road-tire characteristics. The effectiveness of the proposed estimation and control methods is confirmed by numerical simulation. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 56–63, 2001
34 citations
TL;DR: In this paper, a decentralized load frequency control (LFC) based on H∞ optimal control theory with an observer was proposed, which requires only frequency and tie-line power deviation in each area.
Abstract: This paper presents a decentralized load frequency control (LFC) based on H∞ optimal control theory with an observer. A few LFC schemes have been proposed based on the optimal control theory, but they have not considered the change of system parameters in operation and the characteristics of load disturbances in a target system. In this paper, H∞ robust control is introduced to address such problems. Owing to its practical merit, the proposed control scheme is a decentralized LFC. Employing observer theory, the proposed method requires only frequency and tie-line power deviation in each area. Numerical simulations are shown to demonstrate the effectiveness of the proposed method. H∞ control was proven to show greater effectiveness of damping disturbance over the conventional optimal control by the design of control systems aimed at restricting the H∞ norm of its transfer function. In particular, when a decentralized LFC is applied, by reducing the system size, H∞ norm is easier to dampen; thus H∞ control is more effective in the decentralized control. Future research topics include the design of H∞ control system with a weight on frequency response. © 2001 Scripta Technica, Electr Eng Jpn, 136(3): 28–38, 2001
23 citations
TL;DR: Two position and speed estimation algorithms using the current differences between the actual and the estimated currents are proposed and the effectiveness of the proposed algorithm has been verified with a six-pole, 1.5-kW, 1500-rpm test motor.
Abstract: This paper presents a position sensorless drive of salient-pole PM synchronous motors in all speed ranges including zero speed. Two position and speed estimation algorithms using the current differences between the actual and the estimated currents are proposed. One is based on the back emf estimation in the medium- and high-speed ranges. Another is based on the position dependency of the winding inductances in the low-speed ranges including zero speed. The effectiveness of the proposed algorithm has been verified with a six-pole, 1.5-kW, 1500-rpm test motor. Stable sensorless speed control from zero to 3000 rpm within ±100% load torque range was achieved. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 64–73, 2001
21 citations
TL;DR: In this article, the solar energy fraction or auxiliary energy fraction (AUX) is used as a figure of merit for system evaluation, and these indices are shown to be affected by the COP (coefficient of performance) of AUX and by the ratio of the DHW (domestic hot water) load to the annual synthetic load.
Abstract: Possible designs for a self-sufficient residential binary solar energy include a side-by-side system, a PVT hybrid system, and a side-by-side PVT hybrid system. We designed and performed an annual performance simulation of three systems: PV with flat plate collector (PV/FPC), photovoltaic-thermal hybrid (PVT), and PV with photovoltaic-thermal hybrid (PV/PVT) including an electrical auxiliary heat pump. In this paper, the solar energy fraction (SEF) or auxiliary energy fraction (AUX) is used as a figure of merit for system evaluation. These indices are shown to be affected by the COP (coefficient of performance) of AUX and by the ratio of the DHW (domestic hot water) load to the annual synthetic load.
The best results were achieved by the side-by-side PV/PVT hybrid system. Using PVT with PV leads to an improvement of the SEF or AEF compared with the PVT system alone. Glazing is found to be indispensable for the PV/PVT system with an AUX COP of 1, but is unnecessary for a PV/PVT system with a higher COP. © 2001 Scripta Technica, Electr Eng Jpn, 137(1): 28–35, 2001
19 citations
TL;DR: In this paper, the minimum breakdown field strength at lightning impulse and the temperature rise of the conductor and enclosure as measured for N2/SF6 mixtures were investigated for a gas-insulated bus.
Abstract: In designing a gas-insulated bus (GIB) using N2/SF6 mixtures, there are many application problems, such as the mixture pressure needed in order to maintain the required dielectric and heat transfer performance. Problems of recycling SF6 are also essential in applying N2/SF6 mixtures. This paper presents the minimum breakdown field strength at lightning impulse and the temperature rise of the conductor and enclosure as measured for N2/SF6 mixtures. Considering the dielectric and heat transfer properties, we clarify the problems of application of mixtures to a GIB and discuss the appropriate mixture ratio of SF6 in designing a GIB comparable to the present dimensions. In addition, the lowest limit of SF6 content in a liquefied recovering method is theoretically estimated for reference in practical SF6 recovery from mixtures. It is important for design to consider both breakdown phenomena, including the area effect of electrode, and the heat transfer properties of mixtures. © 2001 Scripta Technica, Electr Eng Jpn, 137(4): 25–31, 2001
17 citations
TL;DR: In this article, a 16-pole, 18-coil permanent magnet motor with a rating of 600 Nm and 300 rpm was designed and constructed under restricted dimensional specifications and electrical requirements.
Abstract: This paper presents an optimum design approach for low-speed, high-torque permanent magnet motors. The approach is divided into two steps: the first consists of the rough estimation of torque by linear analysis, and the second the optimization of the motor configuration by nonlinear FEM analysis. Under restricted dimensional specifications and electrical requirements, a 16-pole, 18-coil permanent magnet motor with a rating of 600 Nm and 300 rpm was designed and constructed. © 2001 Scripta Technica, Electr Eng Jpn, 135(4): 52–63, 2001
16 citations
TL;DR: In this article, a miniature actuator consisting of piezoelectric and electromagnetic elements is proposed to move in the x, y, and θ directions without guide rails.
Abstract: We propose a miniature actuator which can move in the x, y, and θ directions without guide rails. The proposed actuator consists of piezoelectric and electromagnetic elements. The structure of the actuator and the principle of its motion are described. Since the electromagnetic path of the proposed actuator does not have an air gap, the proposed actuator uses the electromagnetic flux effectively. The electromagnetic force is controlled to hold the actuator on a slope. The measured electromagnetic force is large enough for the actuator to be held on a slope. Small linear and rotational displacements are realized by deformations of the piezoelectric elements. The linear and rotational displacements were proportional to the applied voltage of the piezoelectric elements. Both micrometer-order linear step displacement and microradian-order rotational step displacement are realized. © 2001 Scripta Technica, Electr Eng Jpn, 134(4): 70–75, 2001
15 citations
TL;DR: AFC control of BTB active power flow, which is in phase with frequency deviations both in the Hokuriku AC power system and in the rest of the power system of central and western Japan, can effectively reduce frequency fluctuations as discussed by the authors.
Abstract: AFC control of BTB active power flow, which is in phase with frequency deviations both in the Hokuriku AC power system and in the rest of the power system of central and western Japan, can effectively reduce frequency fluctuations. In the first section of this paper, test measurements of real large-scale power system fluctuation loads are presented and a dynamic fluctuation load model is derived from a study of the test results. We then analyze the effectiveness of this AFC control in reducing frequency fluctuations in the two AC power systems by static and dynamic computational simulations, using our model in MATLAB. Our simulation analyses reveal that the effectiveness of frequency fluctuation reduction by AFC control on BTB active power depends on the capacity scale of the AC power system interconnected with the BTB system. We performed these computations for different states of the power systems, representing summer peak, winter peak, typical spring peak, and summer night conditions. We confirmed that frequency fluctuations can be significantly reduced in a smaller capacity power system by setting a larger AFC gain. © 2001 Scripta Technica, Electr Eng Jpn, 136(4): 15–25, 2001
14 citations
13 citations
TL;DR: In this paper, a control method that allows the steel plate to levitate stably and horizontally is presented. But, as the levitated steel plates are thin and flat in this kind of maglev system, any guide force in conventional maglev systems is not induced.
Abstract: The techniques of maglev are expected to apply not only to railways but also to various fields of industry. As one such field, the application to process lines of steel plates is now in the limelight. However, as the levitated steel plates are thin and flat in this kind of maglev system, any guide force in conventional maglev systems is not induced. Therefore, once the steel plates levitate, the gravity force soon makes them sideslip if the electromagnets are slantingly attached to the base table. This paper deals with a control method that allows the steel plate to levitate stably and horizontally and deals with various experimental results. © 2001 Scripta Technica, Electr Eng Jpn, 135(2): 52–59, 2001
TL;DR: In this article, the authors discuss the extent to which distribution system loss can be reduced if DGs are optimally allocated on the demand side of the distribution system, and an algorithm based on tabu search is employed.
Abstract: Dispersed generators (DGs) such as fuel cells and solar cells will be installed on the demand side of power systems. Such dispersed facilities can reduce distribution system loss by appropriate allocation. Planning and operation of distribution systems with the dispersed facilities have already been discussed. In this paper, the authors discuss the extent to which distribution system loss can be reduced if DGs are optimally allocated on the demand side of the distribution system. In order to determine the optimal allocation and size of DGs so as to minimize the distribution system loss, an algorithm based on tabu search is employed. The proposed algorithm consists of iterated nested use of the tabu search algorithm. Namely, in the proposed algorithm, in one computational iteration, after the location of the DG is temporarily determined by tabu search, the size of the DG is also determined by tabu search so as to minimize the distribution system loss for the temporarily determined allocation. Numerical simulations are carried out for two system models in order to examine the validity of the algorithm. © 2001 Scripta Technica, Electr Eng Jpn, 136(2): 1–8, 2001
TL;DR: In this article, the p-q theory and the cross-vector theory were compared in three-phase four-wire systems, with the focus on similarities and differences between the two theories.
Abstract: This paper discusses “the p–q theory” and “the cross-vector theory” in three-phase four-wire systems, with the focus on similarities and differences between the two theories. They are perfectly identical if no zero-sequence voltage is included in a three-phase three-wire system. However, they are different in definition of the instantaneous active power and instantaneous reactive power in each phase if a zero-sequence voltage or current is included in a three-phase four-wire system. Based on both theory and computer simulation, this paper leads to the following conclusions: An instantaneous reactive-power compensator without energy storage components can fully compensate for the neutral current even in a three-phase four-wire system including a zero-sequence voltage or current, when a proposed control strategy based on the p–q theory is applied: However, the compensator cannot compensate for the neutral current fully, when a conventional control strategy based on the cross-vector theory is applied. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 74–86, 2001
TL;DR: In this paper, the authors proposed a noncontact energy transfer system using a tuned pickup coil and an immitance converter inductively coupled to a parallel transmission line excited by a high-frequency constant-current source.
Abstract: Noncontact energy transfer systems are widely used in industrial material handling systems. This paper proposes a new noncontact energy transfer system using a tuned pickup coil and an immitance converter inductively coupled to a parallel transmission line excited by a high-frequency constant-current source.
In a noncontact energy transfer system which supplies continuous energy to movers by electromagnetic induction, the efficiency is low owing to low excitation impedance because of the wide air gap of the magnetic core in the pickup coil. The excitation impedance can be increased by the resonance with a capacitor connected parallel to the pickup coil. The resonant pickup coil works as a high-frequency constant-current source for the load. We propose using an immittance converter to transform the high-frequency constant-current source into a high-frequency constant-voltage source. Then, the high-frequency constant-voltage source is rectified into a constant-voltage dc source, and supplies power to an inverter for motor driving.
In this paper, the configuration of this new noncontact energy transfer system and its characteristics are described. The experimental results and simulation waveforms are also described. © 2001 Scripta Technica, Electr Eng Jpn, 136(4): 58–64, 2001
TL;DR: It was found that the organ conductivity value very much affected the induced current distribution inside the human body.
Abstract: Regarding the possible biological effects caused by exposure to ELF (extremely low frequency) magnetic fields, magnetically induced current inside the human boldy has been a focus of research. To clarify the induced current characteristics inside the human body, we develop estimation tools. One was a numerical calculation code and the other was a human model. The numerical calculation code was based on a surface charge method. The human model was composed of several organs and other parts of the human body, whose shapes were spheroids or cylinders. Organs taken into account were the brain, heart, lungs, liver, and intestines. The validity of the calculation code was shown by comparing it with an analytical solution using a homogeneous spheroid model. The discrepancy was within 6.5%. Applicability of the code to the human body was shown. In addition, by applying the calculation code to the human model, effects of organ conductivity differences vis-a-vis the induced current distribution were estimated. It was found that the organ conductivity value very much affected the induced current distribution inside the human body. © 2000 Scripta Technica, Electr Eng Jpn, 134(2): 1–10, 2001
TL;DR: In this paper, the effect of static magnetic fields on the metabolic activity of mitochondria from the viewpoint of their energy level was investigated. But the results of the MTT assay indicated that the mitochondrial energy activity was enhanced by a factor of 1.5.
Abstract: This study intends to clarify the effect of a static magnetic field on cellular activities. It is concerned with the metabolic activity of mitochondria from the viewpoint of their energy level. As a preliminary examination, the time required to render the cells to the low-energy state (G0/G1 phase of the cell cycle) and to reduce their energy level was examined by maintaining the cells in medium with low-density fetal bovine serum. Then, we examined the effect of the magnetic field on mitochondrial energy activity from the viewpoint of cell metabolism estimated by the MTT assay. We also examined the cell respiration, expecting that the mitochondrial energy activity level would be reflected in the respiration. The magnetic field was kept at 100 mT, with 0 mT as the control. The results of the MTT assay indicated that the mitochondrial energy activity was enhanced by a factor of 1.5. We found that the cell respiration was increased by a factor of 1.3 on exposure to the magnetic field. The t-test showed the difference to be statistically significant. It is thus concluded that mitochondrial energy activity is enhanced in the G0/G1 phase of the cell cycle by exposure to a magnetic field. On the other hand, we also found that the mitochondrial energy cycle period is little affected. © 2001 Scripta Technica, Electr Eng Jpn, 137(1): 36–41, 2001
TL;DR: In this article, the authors performed the modeling of the NEDO 500-kW wind generator by a system identification technique using the measured data and clarified the basic characteristics of the generator based on the model.
Abstract: The 500-kW wind generator was developed as one of NEDO's projects, and it has been operated at TAPPI wind park since October 1996. Since then, several tests on its performance have been made. One of the most important characteristics concerns the dynamic behavior under fluctuating wind conditions. For this purpose, we performed the modeling of the NEDO 500-kW wind generator by a system identification technique using the measured data. Next, we clarified the basic characteristics such as transient response and frequency response of the generator based on the model. We confirmed that the simulated results of dynamic behavior almost agree with the measured results. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 37–47, 2001
TL;DR: In this article, the authors proposed a power factor correction scheme using a voltage doubler rectifier without switching devices, where the input current is divided into two periods, where one period charges the small input capacitor and the other charges the large output capacitor.
Abstract: For rectifier circuits with a small capacity, such as those for consumer electronics and appliances, capacitor input-type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been reported. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to overload, and brings low radio noise benefits. We propose a power factor correction scheme using a voltage doubler rectifier without switching devices. In this method, the input current is divided into two periods, where one period charges the small input capacitor and the other charges the large output capacitor. By dividing the input current into two different modes, the current conduction period can be widened and harmonics can largely be canceled between the two modes. Hence, the harmonic characteristics can be significantly improved, whereby the lower-order harmonics, such as the fifth and seventh orders, are much reduced. The results are confirmed by theoretical and experimental implementations. © 2001 Scripta Technica, Electr Eng Jpn, 137(3): 52–58, 2001
TL;DR: In this paper, a circuit model of an oil-immersed transformer for use in surge analyses in the highfrequency region is proposed, and its effectiveness is evaluated by comparison with measurements on a model winding.
Abstract: A circuit model of an oil-immersed transformer for use in surge analyses in the high-frequency region is proposed, and its effectiveness is evaluated by comparison with measurements on a model winding. The circuit model is used for lightning surge analyses of a 500-kV substation, and the effect of transformer modeling on the lightning surge voltage at the transformer terminals is investigated. When the new circuit model is used for transformer modeling, the peak value of the surge voltage is lower but the rate of voltage rise is higher than in conventional transformer modeling by a lumped capacitance. This difference can be explained in terms of the charging of capacitances in the transformer model. © 2000 Scripta Technica, Electr Eng Jpn, 134(1): 28–35, 2001
TL;DR: In this paper, the authors proposed new mathematical models with stator core (iron)-loss factor for induction motor supposed to generate precise and/or efficient torque via vector control, which are composed of three basic vector equations in general frame of arbitrary angular frequency.
Abstract: This paper proposes new mathematical models with stator core (iron)-loss factor for induction motor supposed to generate precise and/or efficient torque via vector control. The proposed models take the structure that stator core-loss resistance is equivalently placed purely in parallel with stator inductance. It is shown that stator core losses consisting of eddy-current and hysteresis losses can be properly represented by the parallel resistance, especially eddy-current loss by a constant one. The models are composed of three basic vector equations in general frame of arbitrary angular frequency such as 4th order differential equation describing motor dynamics, torque equation and energy conversion equation. These basic equations are essential for vector control design taking core-loss into consideration. The proposed models are most compact in sense of number of both of employed parameters and interior states of the motor. Compactness is an important factor for modeling and is useful for designing vector control systems.
TL;DR: In this paper, the authors proposed an active common-noise canceler (ACC) circuit for cancellation and compensation of common-mode voltage caused by a PWM inverter, which is effective in reducing not only conducted EMI but also motor shaft voltage and bearing current.
Abstract: This paper deals with active circuits for cancellation and compensation of common-mode voltage caused by a PWM inverter. A nonnegligible amount of leakage or ground current flows through stray capacitors between stator windings and the motor frame due to a large step change in the common-mode voltage at every switching operation of the PWM inverter. First, it is shown experimentally that the active common-noise canceler (ACC), which has been proposed by the authors, is effective in reducing not only conducted EMI but also motor shaft voltage and bearing current. Next, a new ACC characterized by an isolated power supply is developed to enlarge the applicable voltage range in which it is possible to integrate the ACC with a PWM inverter. Furthermore, the authors propose another type of ACC, the purpose of which is not to achieve complete cancellation but to restrain only a slope in a change of the common-mode voltage applied to the motor. As a result, the core size of the common-mode transformer used in the active compensating circuit becomes considerably smaller. Some experimental results show good effects of the proposed active circuits on both ground current and conducted EMI. © 2001 Scripta Technica, Electr Eng Jpn, 137(1): 57–65, 2001
TL;DR: In this paper, the characteristics of the generation of a high-energy electron beam by a channel spark discharge were investigated, and it was shown that a high energy electron beam was produced in the pressure range from 0.4 Pa to 3.1 × 10-3 Pa in the vacuum chamber.
Abstract: The characteristics of the generation of a high-energy electron beam by a channel spark discharge were investigated. After a hollow cathode discharge in low-pressure nitrogen gas, a pulsed high voltage of –8 to –20 kV from a 2- to 32-nF capacitor initiated a channel spark discharge in a glass tube with an internal diameter of 8 mm. Using a newly designed experimental apparatus, it was shown that a high-energy electron beam was produced in the pressure range from 0.4 Pa to 3.1 × 10–3 Pa in the vacuum chamber. Varying the internal diameter at the end of the glass tube between 16.8 mm and 0.1 mm controlled the diameter of the electron beam. Measurements of the energy distribution of the electron beam revealed that the mean electron energy was approximately 12 keV at the charging voltage of the 20-kV capacitor. The optimum power density of 1.4 × 108 W/cm2 was obtained by using a glass tube with an internal diameter of 2.7 mm at the end at a pressure of 0.4 Pa. © 2001 Scripta Technica, Electr Eng Jpn, 134(4): 10–18, 2001
TL;DR: In this article, the surface roughness positively affects the charging of cylindrical insulators made of PMMA, PTFE, or Al2O3 under ramped and stepped dc voltage.
Abstract: This paper describes the charging phenomena of cylindrical insulators made of PMMA, PTFE, or Al2O3 under ramped and stepped dc voltage. It is primarily concerned with the influence of surface roughness on the formation of charging for various insulating spacers. By using an electrostatic probe located on the cathode, we conducted real-time observations of the electric field induced by the surface charge. It was found that the surface roughness positively affects the charging, which becomes more pronounced in insulators polished to a higher degree. Furthermore, polished insulators are characterized by a shorter time lag. These results show the importance of surface treatment for insulating spacers in vacuum. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 16–25, 2001
TL;DR: In this article, a novel PWM control scheme for a three-phase current source inverter of a photovoltaic (PV) generation system connected to a utility is proposed.
Abstract: A novel PWM control scheme for a three-phase current source inverter of a photovoltaic (PV) generation system connected to a utility is proposed. The PV-array output power can be adjusted by controlling the modulation factor in the proposed PWM pattern. The harmonic components of the output currents can be decreased sufficiently to satisfy the requirements of the Interactive Guidelines. Furthermore, a new Maximum Power Point Tracking control is proposed. The inverter output current should be detected, and the modulation factor may be controlled so as to obtain the maximum effective current. The inverter output power can be maintained at the maximum power point despite fluctuations of panel temperatures, insolation levels, and system voltages. © 2001 Scripta Technica, Electr Eng Jpn, 135(1): 43–55, 2001
TL;DR: In this paper, a phase-shifted PWM full bridge inverter-type high-voltage DC-DC power converter with a high voltage transformer parasitic link and its fuzzy-based learning controller is presented for use in a medical X-ray power generator operating at a wide variety of load settings.
Abstract: In general, medical-use high-voltage X-ray power generators are operated at a variety of required output DC voltages and output current settings for the X-ray tube. A phase-shifted PWM inverter-fed DC–DC power converter with a high-voltage transformer parasitic resonant link which is used for an X-ray power generator inherently has stiff nonlinear characteristics due to phase-shifted voltage regulation and diode cutoff operation in a high-voltage rectifier because of the wide load setting ranges in practical applications. However, the superior output voltage response required for a medical-use X-ray power generator could not be sufficiently implemented by various modern linear control approaches because a precise mathematical description with dynamic modeling could not be formulated for wide load variations. For controlling such a nonlinear DC–DC power conversion system, a fuzzy reasoning-based learning control technique that duplicates human capabilities and much experience in understanding the dynamic and static behavior of the system are more suitable and effective. This paper presents a phase-shifted PWM full bridge inverter-type high-voltage DC–DC power converter with a high-voltage transformer parasitic link and its fuzzy-based learning controller, which has excellent dynamic and static behavior, for use in a medical X-ray power generator operating at a wide variety of load settings. The effectiveness of the feasible fuzzy learning technique used for control of the DC–DC power converter is discussed and evaluated based on computer simulations and experimental results in a laboratory setup. It is demonstrated that the feasible fuzzy learning control scheme suitable for this converter is more effective and practical in improving the system output voltage response performance in both transient and steady states for medical-use X-ray power generators. The results of simulations and experiments for this converter are presented in order to illustrate the operating performance of the proposed X-ray power generator operated by the feasible fuzzy-based learning control implementation. © 2001 Scripta Technica, Electr Eng Jpn, 136(2): 58–71, 2001
TL;DR: In this article, a fuzzy model of nonlinear position-dependent magnetizing curves is presented for position sensorless control of a 1.5-kW, 5400-rpm switched reluctance motors.
Abstract: Among various variable speed drives, switched reluctance motors (SRMs) have been found to be competitive with traditional ac and dc motors because of their simple construction and drive electronics. However, the necessity of using a shaft-mounted position sensor is one of the drawbacks of the SRM from the standpoint of cost, size, and reliability. Position sensorless SRM drives are expected to solve these problems. This paper presents a method of position sensorless control based on a simple fuzzy model of nonlinear position-dependent magnetizing curves. The sensors needed for the drive are one voltage sensor and one current sensor. Experimental studies using a 1.5-kW, 5400-rpm SRM with a 6/4 tooth configuration show that the maximum error of rotor position estimation is less than three mechanical degrees in the 1:20 speed range under any load conditions. © 2001 Scripta Technica, Electr Eng Jpn, 135(2): 60–68, 2001