Showing papers in "Ieej Transactions on Industry Applications in 2002"
TL;DR: In this article, the authors proposed a simple structure integrating position information both in the magnet and in the inductance into one extended electromotive force term to solve the problem of unstable synchronous motors.
Abstract: Salient-pole permanent magnet synchronous motors have been widely used in industrial applications for their high efficiency. To control these motors, knowledge of rotor position and velocity are necessary and expensive sensors have been used to detect these signals. Although many sensorless control algorithms have been developed for cylindrical permanent magnet motors, they cannot be applied for salient-pole machines without any approximation because of the complicated mathematical model, and this may lead to unstable problems. To solve this problem, new extended electromotive force models for synchronous motors have been proposed in this paper. The proposed models have a simple structure integrating position information both in the magnet and in the inductance into one extended electromotive force term. Using these models, no approximation is necessary. Experimental results show that the proposed model and method are valid.
94 citations
TL;DR: In this article, the authors proposed a novel V/f control method for PM motor drive system without position sensor, which does not require high performance digital processing and can achieve high efficiency without explicit estimation of dq-axis.
Abstract: This paper proposes a novel V/f control method for PM motor drive system without position sensor. Unlike sensorless vector control, V/f method does not require high performance digital processing.This paper presents three novel topics for V/f control. At First, instability of conventional V/f control is shown, and a stabilization method consisting of a high-pass -filter and a feed back from d-axis current is proposed. After that, a control strategy yielding high efficiency is introduced. It is shown that the condition id=0, corresponding to high efficiency operation for SPM, can be achieved without explicit estimation of dq-axis. Furthermore, since this method is based on the evaluation of the reactive power, knowledge of R_??_ and e. m. f. is not required. At last, a starting method that does not need flux saturation to decode NS pole of permanent magnet, is proposed. The structure of the resulting control system is very simple and its effectiveness has been confirmed experimentally by using 1.5kW, 3600r/min and 3.7kW, 7200r/min PM motors.
38 citations
TL;DR: A monitoring system for aged people that automatically learns aged people's usual actions in a few days and detects his/her abnormal action by observing the room with a simple camera such as CCD camera is proposed.
Abstract: Japan is now a serious aging society and this problem will be more serious in the near future. Therefore, engineering support for aged people is required. As an important example of such support, a monitoring system for aged people is proposed in this paper. This system automatically learns aged people's usual actions in a few days and detects his/her abnormal action by observing the room with a simple camera such as CCD camera.At the learning stage, Self-Organizing Map (SOM) is used to realize automatic learning. For the detection method, Eigenspace Method is used which is excellent in compression of image data and calculation of the correlation among images. Parametric Eigenspace Method(PEM) is also used to detect abmormalities such as the speed of the action. Some results show the effectiveness of the proposed method.
35 citations
TL;DR: A new model of IPMSM using an extended electromotive force in the rotating reference frame is utilized in order to estimate both of position and speed and the proposed system is very simple and the design of the controller is easy.
Abstract: In most variable-speed drives of PMSM, some type of shaft sensor such as an optical encoder or resolver is connected to the rotor shaft. However, such sensor presents several disadvantages such as drive cost, machine size, reliability and noise immunity. Therefore, the sensorless control of PMSM is desired and various sensorless control strategies have been investigated. This paper presents a novel sensorless control strategy for an interior permanent magnet synchronous motor (IPMSM). A new model of IPMSM using an extended electromotive force (EMF) in the rotating reference frame is utilized in order to estimate both of position and speed. The extended EMF is estimated by the least-order observer, and the estimation position error is directly obtained. The proposed scheme corrects the estimated position and speed so that the estimation position error becomes to be zero. The proposed system is very simple and the design of the controller is easy. Several drive tests are carried out and the experimental results show the effectiveness of the proposed sensorless control system.
31 citations
TL;DR: In this paper, the authors studied properties and reducing techniques of cogging torque in brushless motors with surface permanent magnets and winding slots, and verified the proposed techniques in the combination of poles and slots at typical 12 slots motors by using FEM simulation of two-dimensional model.
Abstract: This paper studies properties and reducing techniques of cogging torque in brushless motors with surface permanent magnets and winding slots. Desirable combination between stator slots and magnet poles, and relation between the slots and added notches are shown. in order to minimize cogging torque, from the standpoint that cogging is mainly generated by fluctuation of 6th and 12th harmonic components in airgap magnetic energy lost by the stator slot openings.Next, the proposed techniques are verified in the combination of poles and slots at typical 12 slots motors by using FEM simulation of two-dimensional model, and it is shown that bevelling of stator pole-tips reduces the cogging torque, especially in the motor with 12 slots and 10 poles.Last, 6 slots and 4 poles motors with the added notches is calculated on the same 2D-FEM and it is shown that type B delivers better result in airgap magnetic flux distribution with rising part of quasi-sinusoidal waveform.
28 citations
23 citations
TL;DR: A new position estimation diagram is proposed and the experimental system together with the control results of the new sensorless elimination method for position control of an Interior Permanent Magne (IPM) motor are shown.
Abstract: In our previous paper, we proposed a new sensorless elimination method for position control of an Interior Permanent Magne (IPM) motor, in which we utilize carrier frequency component current of PWM inverter as the motor position informatio source. In this paper we propose a new position estimation diagram and shows the experimental system together with the control results of the new position control method. With this control scheme, the motor speed has been successfully controlled from zero speed to 1, 400rpm (1.4 times rated speed) without mechanical sensor.
19 citations
19 citations
TL;DR: In this paper, a linear multiple regression model that evaluates the ride discomfort index (RDI) is proposed using longitudinal acceleration and jerk of the automobile as explanatory variables, and a microcomputer-based driver assistance system that evaluates RDI and informs the driver of the RDI in real time by both visual and auditory means.
Abstract: This paper describes the development of a driver assistance system for improving passenger ride comfort of automobiles. Based on results of psychophysical experiments of subjective ride comfort evaluation, a linear multiple regression model that evaluates the ride discomfort index (RDI) is proposed using longitudinal acceleration and jerk of the automobile as explanatory variables. In order to reduce the ride discomfort caused by the velocity fluctuation of an automobile, a microcomputer-based driver assistance system that evaluates the RDI and informs the driver of the RDI in real time by both visual and auditory means is developed. Experiments show that, with the help of the system, a driver can improve his/her driving skills and modify his/her driving behavior to provide passenger-friendly maneuvers and improve passenger ride comfort, thus verify the usefulness of the proposed driver assistance system.
16 citations
TL;DR: The best combination of human ability and robot capacity is considered and Commands of human by a joy stick are changed into the virtual force commands instead of position commands, and a soft robot is able to be realized.
Abstract: Both human and robot will carry out a task which is not realizable by only each of them. In particular, human recognizes environment and reflects to trajectory planning well. On the other hand, robot generates the controlled force more than human. In this paper, the best combination of human ability and robot capacity is considered. Commands of human by a joy stick are changed into the virtual force commands instead of position commands. Thereby, a soft robot is able to be realized. When it collides with an obstacle, it controls softly to external force in order to relax the shock. This is realizable by applying compliance control to the human input and external force. Reaction force estimation observer is implemented in robot to detect environmental disturbance. Environmental disturbance is classified into the mode of translational direction and rotational direction. By identifying environmental friction coefficient and changing gain of a joy stick, when a passenger and a road surface situation change, the desired operation characteristic is achieved. The proposed method is applied to wheelchair. As a result, operationality and ride quality are improved.The experimental results show viability of the proposed method.
15 citations
TL;DR: In this article, the authors investigated a class of characteristic-varying systems in the D-module, which contains the two-input-two-output (SISO) filters.
Abstract: Signal processing based on frequency polarity has been attracting wide attentions due to its potential industrial-applications. It is popular to employ two vector-rotators for such signal processing. But, It was very recently reported that equivalent signal processing effect can be attained in a much simpler manner using two-input two-output filters in the D-module. This paper further investigates a class of characteristic-varying systems in the D-module, which contains the filters in the D-module as a special case, and gives new analytical results on their properties from viewpoints of existence, realization and stability. If the results are applied to filter problems, n-th order D-module filters in new forms can be easily and directly obtained, whose stability and response equivalent to the associated filters with vector-rotators are guaranteed. If the results are applied to AC motor modeling problems, dynamic models and block diagrams of AC motors in general reference frame are easily and directly obtained. Very general and useful analyses are given for newly proposed a class of characteristic-varying systems in the D-module that have potential usefulness in various industrial applications including control of magnetic bearing system, analyses and active compensations of power systems, and sensorless drives of AC motors.
TL;DR: In this article, the authors deduced a sufficient condition of multi-inertia system stability with PID control and designed the PID controller to meet the sufficient conditions of control system stability.
Abstract: As speed control method of Two-Inertia system, conventional PID control is used well. However, when a gear or a coupling backlash exists in the 2-I system, the conventional PID control may not be able to suppress vibration caused by the backlash. To solve above problem, this paper deduces a sufficient condition of Multi-inertia system stability with PID control. Therefore, if the parameters of the PID controller are designed to meet the sufficient condition of control system stability, stable speed control without backlash vibration can be produced without relation to the presence of the backlash. The parameters of the PID controller can be designed by Coefficient Diagram Method (CDM). The effectiveness of the proposed speed control method will be shown by both simulations and experiments.
TL;DR: In this article, a linear oscillatory actuator with dynamic vibration control is proposed. But it needs complicated construction for cylindrical models, and it is not suitable for use in the real world.
Abstract: Linear oscillatory actuator can produce high-speed rectilinear vibration efficiently, without motion converting mechanisms. However, we need to reduce the reaction force and moment caused by main vibration for its application. So far, the method for vibration reduction that two moving elements of magnetic circuit are counter driven is reported, but it needs complicated construction for cylindrical models. In order to solve this problem, we propose linear oscillatory actuator with dynamic vibration control as a new construction and describe its principle of operation. Furthermore, we evaluate the performances of the actuator by computer simulation and confirm them by a prototype.
TL;DR: In this article, a control method of single phase power active filter on d-q coordinate with Hilbert Transformer is presented, where the d-Q components on single phase current and voltage can be obtained.
Abstract: A control method of single phase power active filter on d-q coordinate with Hilbert Transformer is presented in this letter. By using Hilbert transformer, the d-q components on single phase current and voltage can be obtained. Then, harmonic components can be derived from these d-q components instantaneously as well as three phase power active filter systems. The effectiveness of the proposed control method has been verified by the computer simulator and some significant characteristics are also shown in this letter.
TL;DR: In this article, a small-rated passive EMI filter with a three-phase voltage-source PWM inverter was used to eliminate both common-mode and normal-mode voltages from the output voltage of the inverter.
Abstract: This paper deals with an inverter system integrating a small-rated passive EMI filter with a three-phase voltage-source PWM inverter. The purpose of the EMI filter is to eliminate both common-mode and normal-mode voltages from the output voltage of the inverter. The motivation of this research is based on the well-known fact that the higher the carrier or switching frequency, the smaller and the more effective the EMI filter. An experimental system consisting of a 5-kVA inverter, a 3.7-kW induction motor, and a specially-designed passive EMI filter was constructed to verify the viability and effectiveness of the EMI filter. As a result, it is shown experimentally that both three-phase line-to-line and line-to-neutral output voltages look purely sinusoidal as if the inverter system were an ideal variable-voltage, variable-frequency power supply when viewed from the motor terminals. This results in completely solving serious issues related to common-mode and normal-mode voltages produced by the inverter.
TL;DR: In this article, a power convertion system is proposed to compensate the output power of a partially shaded PV array, which contributes to a more efficient implementation of the PV power compensation system than that by individual controls of PV modules using DC-DC converters.
Abstract: The power-voltage and current-voltage characteristics of a PV array change with the variation of insolation and temperature. Especially, the output power of a PV-panel block consisting of series-PV modules inevitably goes down due to partial shading caused by peripheral obstacles. This results in the significant reduction of the total output power from the PV power generation system where a couple of PV blocks are parallel to the DC terminal of interactive inverter because of mismatch of the optimum operating voltages between the PV blocks.In this paper, we propose a power convertion system to compensate the output power of a partially shaded PV array. The proposed system can control the output power of the PV array on a PV block basis, which contributes to a more efficient and simpler implementation of the PV power compensation system than that by individual controls of PV modules using DC-DC converters. In addition to that, inverter DC voltage is appropriately controlled so that the maximum output power from the overall PV array can be obtained. And then, the feasibility of the system is investigated and verified from the simulation and experimental results.
TL;DR: In this article, the authors developed a method for the strand current distributions in the turbine generator armature windings by using a circuit equation and a 3D finite element method, which had good agreement with the measurements of 360-degree, 450-degree and 540-degree transposed model coils.
Abstract: We have developed a calculation method for the strand current distributions in the turbine generator armature windings. These distributions are calculated by using a circuit equation and a 3D finite element method. In the circuit equation, the strand current is solved by introducing a circulating current at each strand of the armature windings. The induced voltage in the circuit equation is produced by leakage flux of the coil end region. The leakage flux is obtained by the 3D finite element method. The calculated strand current distributions had good agreement with the measurements of 360-degree, 450-degree and 540-degree transposed model coils.
TL;DR: In this article, a snubberless IGBT series connection with active gate control is proposed, where the collector-voltages of IGBTs connected in series can be balanced by uniting the collector voltages of each single IGBT independently.
Abstract: High voltage IGBT converters require an IGBT series connection. To reduce converter loss and simplify converter configuration, snubber circuits should be omitted. In this paper we introduce our snubberless IGBT series connection technique with active-gate-control.In the active-gate-control IGBT, gate-voltage is set to increase with collector-voltage. Due to increased gate-voltage, IGBT impedance drops and the collector-voltage is limited. The collector-voltages of IGBTs connected in series can be balanced by uniting the collector-voltages of each single IGBTs independently. In the active-gate-control, the gate is charged before the collector-voltage reaches the clamping voltage. So fast control can be performed and surge voltages at the recovery state can be clamped. In the control the clamping voltage increases with tum-off current and it is saturated for further larger currents. By increasing the clamping voltage with tum-off current, the increase of tum-off loss caused by collector voltage clamping is limited. Saturating the clapping voltage for further higher currents prevents overvoltage failure.
TL;DR: In this paper, the authors proposed a new concept that the end effect can be compensated only by the supply of secondary current synchronized with the current of LIM in front of the entry end of LIM, without considering with the flux density distribution in the LIM primary region.
Abstract: For the end effect of linear induction motor (LIM), the authors propose a new concept that the end effect can be compensated only by the supply of secondary current synchronized with the current of LIM in front of the entry end of LIM, without considering with the flux density distribution in the LIM primary region. As a concrete method to supply the secondary current in front of LIM, the authors propose the rotator with rare-earth type permanent magnets which has strong flux density without ohmic loss, and does not cause the power factor problem even for the influence of end effect. The results of analytical study on the numerical example of LIM designed for subway are as follows. This method can make the flux density and thrust density distribution in the LIM primary region almost agree with those of the case without end effect. This method can compensate the thrust, power factor, efficiency of LIM at the rated speed to coincide with the characteristics without end effect. There is no problem in the slip characteristic curves of LIM with the compensator, although the compensator only rotates synchronizing with the frequency of LIM. The effect of compensation becomes large in the lower slip. The force to rotate the compensator is very small in the suitable design.
TL;DR: In this paper, a nonlinear modeling of a permanent magnet induction machine (PMIM) is presented, where an electrical equivalent circuit that can accurately include the nonlinearity of the excitation circuit is derived and a measuring method of circuit parameters and a calculation method of the steady-state performance is explained.
Abstract: This paper presents the nonlinear modeling of a permanent-magnet induction machine (PMIM). The PMIM has a permanent-magnet (PM) rotor that is free to rotate inside a squirrel-cage rotor. The internal self-excitation from this PM rotor allows the PMIM to operate at a higher power factor. Utilizing a duality between magnetic and electric circuits, an electrical equivalent circuit that can accurately include the nonlinearity of the excitation circuit is derived. Based on this equivalent circuit, a measuring method of circuit parameters and a calculation method of the steady-state performance are explained. In addition, the generating characteristics of the PMIM in the grid-connected mode are theoretically calculated to verify the validity of the derived equivalent circuit, and the results are confirmed through experiments.
TL;DR: This paper proposes a novel visual servoing system with Motion Observer (MOB) based Feature Prediction and shows the effectiveness of the proposed method is shown through simulations and experiments.
Abstract: Visual servo is the eye-in-hand robot system directly using real time visual information for control. In this paper, we propose a novel visual servoing system with Motion Observer (MOB) based Feature Prediction. The position of the target object cannot be directly observed. Motion Observer is designed using a minimum order observer and is useful for high performance servoing. We show the effectiveness of the proposed method is shown through simulations and experiments.
TL;DR: In this paper, a transformerless shunt hybrid filter for harmonic compensation of a three-phase six-pulse diode rectifier is proposed, where the ac line-to-line voltage is 3.3kV or 6.6kV.
Abstract: This paper proposes a transformerless shunt hybrid filter for harmonic compensation of a three-phase six-pulse diode rectifier, where the ac line-to-line voltage is 3.3kV or 6.6kV. The hybrid filter consists of a single tuned LC filter per phase and an active filter with a dc capacitor voltage as low as 300V or 600V. The two filters are directly connected in series with each other without any transformer. The passive filter absorbs harmonic currents produced by the rectifier, whereas the active filter improves the filtering characteristics of the passive filter. The required rating of the active filter is much smaller than that of a conventional shunt active filter used alone. In addition, no additional switching-ripple filter is required for the active filter, because the LC filter acts not only as a tuned LC filter around the 7th-harmonic frequency but also as a switching-ripple filter around 10kHz. A feedforward control scheme is also proposed to improve the active filter performance. Experimental results obtained from a 200-V, 5-kW laboratory system and simulation results of a 3.3-kV, 300-kW system confirm the validity and effectiveness of the system. The hybrid filter gives satisfactory compensation performance, thus allowing us to put it into practical use.
TL;DR: This paper proposes a new estimation method of the reference input signal by using only tracking error, and realizes the high speed robust tracking servo system with ZPET control and considers the saturation of controller output.
Abstract: This paper proposes a new high speed robust tracking control system based on both “Zero Phase Error Tracking” (ZPET) control system and robust servo system for an optical disk recording system. In the optical disk recording systems (for example CD-R), the tracking servo system must have the complete tracking response whose error is less than 0.1 [μm] for an amplitude of 100 [μm] of reference input signal. However, its detecting signal is only a tracking error. For this purpose, this paper proposes a new estimation method of the reference input signal by using only tracking error, and realizes the high speed robust tracking servo system with ZPET control. Moreover, this paper considers the saturation of controller output. The experimental and simulation results point out that the proposed system has a quick and precise tracking response.
TL;DR: In this paper, the authors presented an efficient high-frequency soft switching PWM boost chopper controlled DC-DC power converter with a single auxiliary passive resonant snubber, which is more suitable and acceptable for high power applications.
Abstract: Abstract-This paper presents an efficient high-frequency soft switching PWM boost chopper controlled DC-DC power converter with a single auxiliary passive resonant snubber, which is more suitable and acceptable for high power applications. The proposed boost chopper type power converter capable of operating under soft commutation principles of series inductor-assisted Zero Current Soft Switching (ZCS) at turn-on transition and parallel capacitor-assisted Zero Voltage Soft Switching (ZVS) at tum-off transition is more effective to reduce switching power losses of an active power switch and EMI noises relating to switching surges on the basis of the DC load side power recovery feedback power processing. The operating principle of soft switching boost chopper type DC-DC power converter treated here is described and its performance evaluations are discussed and evaluated through simulation and experimental set-up for 5 kW power rating specification. The validity and effectiveness of this soft switching PWM boost type power converter using IGBTs are proved as compared with some performances of a hard switching boost chopper type power converter from an experimental point of view. The modified soft switching converter topologies using a single passive resonant snubber are demonstrated in here.
TL;DR: A zero current switching strategy of the PWM rectifier section during zero voltage vector periods of the inverter section is described and verified by computer simulation and experimental test on an induction motor drive.
Abstract: A converter without DC Link components needs snubber circuits, in order to assure the path of the load current during the dead-time period of the PWM rectifier section. In the snubber circuits, losses have been dissipated every time the switches of the rectifier section are turned on and turned off. During the zero voltage vector period of the inverter section, the load current does not flow in the PWM rectifier section. So if each switching operations of the PWM rectifier section are done in the zero voltage vector period, it is not necessary to assure the path of the load current. Therefore, snubber circuits are not necessary in the PWM rectifier section. In this paper, we describe a zero current switching strategy of the PWM rectifier section during zero voltage vector periods of the inverter section. The proposed strategy is verified by computer simulation and experimental test on an induction motor drive.
TL;DR: In this paper, the authors proposed a power factor correction scheme using a LC resonant in commercial frequency without switching devices, which makes a sinusoidal wave by widening conduction period using the current resonance.
Abstract: For small capacity rectifier circuits 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 presented previously. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. We propose a power factor correction scheme using a LC resonant in commercial frequency without switching devices. In this method, It makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced. The results are confirmed by the theoretical and experimental implementations.
TL;DR: In this article, a systematic design methodology for discrete control systems is proposed, which is based on Galois field and Grobner basis, where the controller can be automatically designed using a model of the controlled plant.
Abstract: A systematic design methodology for discrete control systems is proposed, which is based on Galois field and Grobner basis. The controller can be automatically designed using a model of the controlled plant. The controlled plant is represented on Galois field. Then the inverse function of the plant is derived using Grober basis so that the input variables are explicitly obtained as the function of the state variable and reference variable. An illustrative example of a material handling system is shown. The proposed method will realize cost reduction in software development and an improvement of reliability and safety of the PLC based systems.