This paper describes the performance of the superconducting linear synchronous motor control system used for a transportation vehicle by using an exact dqO-axis mathematical model. The paper firstly shows the detailed block diagram of the speed control system, which includes the blocks of propulsion force and speed emf computations. A detailed discussion is given to the design of the control system. A cascade control system with PI controllers is designed as a numerical demonstration. It is also pointed out that the cascade control structure is a natural form for the power feeding method with three inverters. Performance simulations are shown for severe track conditions like tunnel and track gradient as well as a normal case. It is demonstrated that an integrator windup of the speed controller can occur in the case of a severe condition that one of the inverters is disabled. We show a design with more robustly stable performance by designing an anti-windup controller.

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It is well known that variable structure (VS) type model reference adaptive controls (MRAC) are robust for disturbances. However almost conventional design schemes of VS-MRAC may cause chattering phenomena because of switching-function used in control synthesis input. In this paper, we propose a new design scheme of MRAC which uses VS-type adaptive identifier. This design scheme can avoid occurrence of chattering phenomena. Furthermore, this design scheme is robust to disturbances.

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In a field of simulation concerning semiconductor power devices, there are process simulation, device simulation, circuit simulation. These simulations are selected for their purpose. In order to analyze static and dynamic phenomena of semiconductor power devices or passive devices, and to support the design of power conversion systems, many circuit simulation models of semiconductor power devices such as GTOs, IGBTs, Thyristors are fabricated.
In this paper, a reverse coducting static induction thyristor model is proposed. The model is made up of SI thyristor model with two transistor analogue and diode model with SPICE internal diode, capacitance and resistance. For confirming the accuracy of this circuit model, some experiments are carried out. As a result, good agreement are shown between the measured and calculated results.

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Single-phase buck-boost rectifier with minimized input current distortion is studied in the paper. To sinusoidally waveshape the input current with a near-unity power factor over a wide variety of operating conditions, the output capacitor is operated with voltage reversibility for the supply by arranging the auxiliary diode and power switching device. Then the output voltage is superposed on the input voltage during on-time duration of power switching devices in order to minimize the input current distortion caused by the small input voltage when changing the polarity. The tested setup, using two insulated-gate bipolar transistors (IGBTs) and a microcomputer, is implemented and IGBTs are switched with 20kHz, which is out of the audible band. Moreover, a rigorous state-space analysis is introduced to predict the operation of the rectifier. The experimental and simulated results confirm that the input current can be sinusoidally waveshaped with a near-unity power factor and a satisfactory output voltage regulation can be achieved.

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To set up active dampers to vehicles is an effective method for improving the ride comfort. However, since conventional active dampers are force generative types, the system will “riot” once the controller fails. In this paper, in order to avoid such kind of troubles a novel semi-active damper which is composed of a cylinder injected with M. F. (Magnetic Fluid) is proposed. However since it has strong nonlinearity a nonlinear controller must be applyed. This paper shows how to design it and the various advantages by digital simulations and experiments.

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A steering control of automated guided vehicles (AGVs) by neural networks was proposed. It was necessary to adjust the coefficients in the teaching signal according to the degree of learning. Thus, it was desired that they were adjusted automatically, then a steering control strategy of AGVs was proposed with the successive learning neural networks using the auto-tuning function (AT function). Since the change of traveling conditions, for example, a cornering radius and a traveling speed, are not considered, the steering control with the AT function is not practical. In this paper, a steering control strategy of AGVs is proposed with a successive learning neural networks using a real-time tuning function (RT function). The coefficients of the proposed RT function and the initial values of the teaching signal are discussed by the computer simulation. The right and left turnig experiments using the AGV built as a trial are performed and the validity of the RT function is discussed. The excellent traveling control of the AGV is obtained in the case that the traveling conditions are changed. Then the learning of the neural networks is almost terminated and after then the excellent traveling lasts. Thus, the proposed RT function is proved to be very available for the successive learning of neural networks.

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In this paper, described is an advanced system parameter control method of auto-tuning implementation for AC servo drive system with mechanically-resonant load using fuzzy reasoning logic with automaticallylearning function.
This method includes three inherent features;
(i) It is not necessary to input some kinds of fuzzy rules to the servo system before starting auto-tuning operation. Thus, the fuzzy rules can be automatically produced in learning logical process.
(ii) Any knowledge and information about system parameter tuning technique are not required.
(iii) Both high speed response and robustness can be obtained.
The feasible effectiveness of this auto-tuning processing approach for the AC servo system is practically confirmed through experimental results.

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The application of single-bit digital signal processing to mechanical control system has already been proposed by the authors. Multi-bit A/D converter has been improved to the high level. But it is difficult to make more high resolution A/D by latest semiconductor technologies. There is single-bit digital signal which is generated by a delta-sigma modulator. Single-bit digital signal has small quantized error around low frequency. Then with this single-bit digital signal processing, high resolution on controlling such a narrow band width mechanical system will be realized. In this paper, resolution of analog, multi-bit and single-bit control systems are estimated with simulation. According to simulations' results, single-bit control system has higher resolution than multi-bit system in the condition of equal bit rate.

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The Current source self-commutated converter has been developed for use in motor drive systems. It however has technical problems such as L-C series resonance, the requirement of transformers for multiple converter connections and DC current unbalance in the converters.
This paper presents a new control method to solve these problems for converters connected directly in parallel. The control method consists of a multiple space vector control including resonance suppression control. Results of a mini-model experiment confirming the control method will also be presented.

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In a large-scale real-time control system, functions of subsystems differ slightly although they seem to be identical. Functions change when hardware is replaced or when the function itself is upgraded. If the standard system is generated and is installed then to each subsystem, subsystems become different with maintenance being carried out in each subsystem to fit its operational conditions. Furthermore, subsystems are distributed in a wide area. Software maintenance therefore becomes very difficult. This paper describes a distributed management for software maintenance in the Tokyo metropolitan-area railway system (ATOS). This management has two phases: distributed management in generating programs and in executing programs. There it contributes to increase the accuracy and ensure the consistency of software maintenance.

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This paper describes a first-order H∞ speed controller which can well regulate load speed without torsional vibration for both speed reference and torque disturbance in a two-mass resonant system. To the strategy for reducing the order of the H∞ controller, the authors apply the state feedback compensation to modify an original resonant plant and disregard the dynamics of the modified plant considering robust stability criterion. Thus, the resulting H∞ controller in speed control systems can be reduced to the just first in order using the modified plant.

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This paper describes position-sensorless control of an interior permanent magnet synchronous motor (IPM motor), which is characterized by real-time position estimation based on magnetic saliency. The real-time estimation argorithm proposed in this paper determines the inductance matrix including rotor position information from current harmonics produced by switching operations of an inverter driving the IPM motor, and then estimates the rotor position every period of pulse-width modulation (PWM). Position estimation without any special signal injection is achieved with a satisfactory response and accuracy even at a standstill and at low speed. An experimental system consisting of an IPM motor and a voltage-source PWM inverter has been implemented and tested to confirm the effectiveness and versatility of the approach. Some experimental results show that the experimental system has the function of electrically locking the loaded motor, along with a position response of 20rad/s and a settling time of 300ms.

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The magnetic properties of core materials and the core conditions were represented in equivalent circuits for motors. In equivalent circuits for motor cores, real inductance L, imaginery inductance r/j and resistance R are connected in parallel to express the frequency dependences of iron losses. L, r, R are related respectively to permeability, hysteresis loss and eddy current loss. The magnetic properties of motor cores are affected by flux distribution, rotational flux, manufacturing stress and space harmonics and time harmonics in motors, and the figures 2, 4, 5 and 6 show the circuits which represent the effects. The equivalent circuits are composed of equivalent circuits for stator, rotor and air gap, and then this equivalent circuit analysis can indicate the most suitable core materials for each part. Using this equivalent circuit, the relationships between the characteristics of motors and the magnetic properties of core materials can be investigated in d. c. motor, synchronous motor, induction motor. reluctance motor (RM) and switched RM.

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This paper presents a novel two-dimensional homopolar linear dc motor (LDM) which can realize two-dimensional (2-D) motion. For position control purposes, two kinds of position detecting methods are proposed. The position in one position is detected by means of a capacitive sensor which makes the output of the sensor partially immune to the variation of the gap between electrodes. The position in the other direction is achieved by exploiting the position dependent property of the driving coil inductance, instead of using an independent sensor. The position control is implemented on the motor and 2-D tracking performance is analyzed. Experiments show that the motor demonstrates satisfactory driving performance, 2-D tracking error being within 5.5% when the angular frequency of reference signal is 3.14rad./s.

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