Abstract: The invention relates to a rotating electric machine including (a) a rotor having a rotating shaft; (b) a bearing for supporting the rotating shaft; (c) a radiation resistant grease applied to the bearing; and (d) a shield layer for shielding the grease from radiation. The shield layer is made of lead and surrounds the bearing. The shield layer includes (1) a first cylindrical shield member that is positioned to cover the bearing, such that the bearing is shielded from a first radiation that is in a direction substantially perpendicular to an axis of the rotating shaft, and (2) second and third disk shield members that are positioned to interpose therebetween the bearing in a direction along the axis of the rotating shaft, such that the bearing is shielded from a second radiation that is in a direction substantially along the axis of the rotating shaft. Thus, the rotor of this rotating electric machine is stably supported in the bearing for a long time even under a highly radioactive environment.

Abstract: An apparatus for a pole change induction motor and control method for the same which are applicable to, for example, a driving source of an electric vehicle without power transmission are disclosed. In the control apparatus and method for the pole change motor is electrically changed between an n number of poles and a 2n number of the poles (n=2, 4, - - - ) so as to secure an output torque of the pole change induction motor in a constant driving mode with a high rotation speed of the induction motor without increase in a dimension of either of the induction motor or an inverter associated with the pole change induction motor and without occurrence in a torque variation. In a preferred embodiment, two channels of exciting and torque instructions and slip frequency generators (current instruction calculating blocks and current control systems) are provided for the n number of pole driving and 2n number of pole driving.

Abstract: In a vector control apparatus and method for an induction motor, a magnetic flux observer of a full order is provided for receiving a primary voltage vector (v.sub.1) and a primary current vector (i.sub.1) and for generating a vector related to an estimated secondary magnetic flux component to be supplied to a current command calculating section and related to an estimate rotation phase of a rotary coordinate system to be supplied to a current controlling section based on the primary voltage vector and the primary current vector, the magnetic flux observer of the full order having a plurality of coefficients expressed in circuit constants of a T-I type equivalent circuit of the induction motor.

Abstract: To estimate nitric acid ions and nitrous acid ions in a sample solution, a method is proposed which comprises the steps of (a) feeding both the sample solution and a reducing agent to an acidic solution which is flowing in a thin pipe; (b) positively mixing the sample solution and the reducing agent and thus reacting the same in a given portion of the pipe; (c) leading the reacted solution to a gas/liquid separator thereby to separate a gaseous phase from the reacted solution; and (d) estimating the nitric acid ions and nitrous acid ions in the gaseous phase.

Abstract: In a drive circuit for a switched reluctance motor, a DC power supply is provided, a plurality of main circuit switching devices cause branched currents from a current derived from the DC power supply to flow through stator windings of the switched reluctance motor sequentially during their turned on states; a plurality of freewheel diodes are provided, each connected across a corresponding one of the main circuit switching devices in a reverse parallel connection; a plurality of reverse flow blocking diodes are provided, each cathode of which is connected to an output end of the corresponding one of the main circuit switching devices; a resonance purpose capacitor is provided whose one end is connected to a plus terminal of the DC power supply via a resistor and whose other end is connected to an anode of each reverse flow blocking diode; a serial circuit is connected across the resonance purpose capacitor and is constituted by a resonance purpose inductor and a resonance purpose switching device for causing

Abstract: A PWM power converter includes a first switching branch of a first switching device and a first inductor between a positive source terminal and a load terminal and a second switching branch of a second inductor and a second switching device between the load terminal and a negative source terminal.

Abstract: A monitoring apparatus for monitoring an operating condition of a system includes a predicting section which generates a data vector whose parameter is determined by a timeseries data of the system and which obtains a prediction value of the timeseries data of a predetermined time future by means of the chaotic inference based on a behavior of attractor which is generated in a reconstruction space by an embedding operation of the data vector. A monitoring section compares the detected value and the prediction value of the timeseries data and decides the condition of the observed system according to the compared result. Therefore, it becomes possible to appropriately and quickly judge as to whether the observed system is in an abnormal condition or not.

Abstract: In a method and apparatus for protecting a plurality of same semiconductor switching elements used in a PWM inverter from being overheated, a junction temperature rise T.sub.n of one of the switching elements is derived on the basis of an output frequency of the inverter (.omega. c), an output current (I) of the inverter, and a control factor (a) and when T.sub.n >T.sub.nref, the overheat in the corresponding switching element occurs so that a gate signal for each switching element is not inputted or an PWM off duty ratio on a pulse duty ratio of the gate signal is increased to limit the output current of the inverter.

Abstract: A power inverter having: three or more PWM-type power inverting units which are so arranged and constructed as to be enabled to be driven in parallel; a plurality of integrated interphase reactors, each of which is so arranged and constructed as to synthesize each of the same phase output currents of the respective PWM-type inverting units and supply the synthesized phase output current to a load such as a three-phase induction motor; a plurality of current balance controllers, each of which is so arranged and constructed as to carry out a retardation correction for a PMW waveform outputted from the respective PWM-type power inverting units in the corresponding phase so that each phase current between the respective PWM-type inverting units is balanced.

Abstract: In apparatus and method for controlling a torque of an induction motor through a vector control method type inverter having a slip frequency calculator arranged for calculating a slip frequency used to perform a vector control for the induction motor and a secondary resistance compensation circuit arranged for correcting the slip frequency by a temperature variation in a secondary resistance of the induction motor, basically a skin effect correction circuit is added for deriving an error component developed in an output of the secondary resistance compensation circuit when a leakage inductance L.sigma.is non-linearly varied due to a skin effect phenomenon.

Abstract: A method for detecting islanding operation of a rotating-machine type dispersed generator. The dispersed generator is interconnected with a main electric source through a circuit breaker to constitute an electric power system. The estimating method is implemented as follows: (a) changing electric power of the electric power system; (b) detecting frequency component of the electric power; and (c) deciding that an islanding operation of the dispersed generator is executed if the change of the frequency component becomes greater than a predetermined value. With this method, it becomes possible to detect the islanding operation of the dispersed generator even if the power flow at the interconnecting circuit breaker is generally zero.

Abstract: A converter includes a rectifier 1 of the diode bridge connected across the alternating current power supply via an input filter F; a circuit 2 having an reactor L.sub.1, switching element Tr1, and the reverse current flow blocking diode D.sub.1 connected across output terminals of the diode bridge; a smoothing capacitor Cd charged according to an energy stored in the reactor L.sub.1 ; and a controller 3 arranged having a comparator 36 for comparing a signal of circuits 31 through 34 which detects a difference between the direct current output voltage Vd and the set (reference) voltage Vs and amplifies thereof with a triangular carrier wave 36 so as to control the transistor Tr1, the transistor Tr1 being controlled to be turned on or off according to the carrier wave frequency. When the transistor Tr1 is turned to ON, the energy is stored in the reactor L1 via the rectifier of the diode bridge 1.

Abstract: An apparatus for executing a short-term prediction of chaotic timeseries data includes a parameter determining section that changes each of parameter values according to the dynamics of observed chaotic timeseries data, and a predicting section that predicts a near future value of objective by reconstructing an attractor of timeseries data of the objective data in a multi-dimensional state space and by using vector neighboring to the data vector including the objective data. Therefore, it becomes possible to quickly and accurately execute a short-term prediction of chaotic timeseries data and to be responsive to the changes of the dynamics of the timeseries data.

Abstract: The invention relates to a solid-electrolyte fuel cell including an anode that is intended to be in contact with a fuel; a cathode that is intended to be in contact with an oxidant for oxidizing the fuel; and a first oxygen-ion-conductive (electrolyte) film and a second oxygen-ion conductive film that are stuck together, are connected with the anode and the cathode, and are arranged in descending order toward the anode, by activation energy of oxygen ion. According to the fuel cell, it becomes possible to increase the open-circuit voltage.

Abstract: An inertia lowering control apparatus for a two-mass inertia system, the two-mass inertia system having a motor (induction motor), a load of the motor, and a flexible drive shaft having a low rigidity interconnected between the motor and load, is used to suppress an axially torsional vibration occurring on the flexible shaft in the two-mass inertia system. For example, the first-order lag filter having a transfer function as 1/(1+ST.sub.F) is added at an output portion of the Simulator Following Control section which serves as a disturbance suppression circuit together with a shaft torque estimating observer to estimate a shaft applied torque .tau..sub.S. A simulation of the above-described example indicated that even if the observer gain of the shaft torque estimating observer was relatively small, the effect of suppressing the axially torsional vibration was remarkable.

Abstract: A terminated cable portion inspection device (8) for a stripped terminal crimping machine, which is located on a bidirectional path (P) between a stripping portion and a terminal crimping portion and includes: an image pickup camera (11) having a high shutter speed; an illuminating device (12) including a pair of illuminating portions (20) on opposite sides of a photographing path (19) of the image pickup camera (11) for directing illumination in substantially the same direction as a photographing direction toward a cable end passing therethrough along the bidirectional path (P) and elongated in substantially the same direction as a longitudinal direction of the cable, and optical fibers (22) for guiding light to light projecting portions (23) of the illuminating portions (20); and a detector (13) including first and second sensors (31, 32) for detecting the cable end.

Abstract: To extend an operable range of a hybrid excitation type permanent magnet synchronous motor having a field of a permanent magnet and a dc excitation coil, magnetic flux of the field is controlled so as to keep constant when a rotation speed of the motor is smaller than a predetermined base speed and so as to change in reverse proportion with the rotation speed of the motor when the rotation speed is larger than the predetermined base speed. Electric current and voltage to an armature of the motor is controlled such that a current ratio of a direct-axis component and a quadrature-axis component which components are obtained by dividing an electric current to the armature coil into the direct-axis component and the quadrature-axis component relative to the voltage induced in the armature coil, is kept constant.

Abstract: A hybrid excitation type permanent magnet synchronous motor is provided with an armature and a rotor core arranged to be rotated relative to the armature. Permanent magnets are installed on the rotor core and generate magnetic flux which passes through the armature through a gap between the rotor and armature. Salient pole portions are integral with the rotor core and are not covered with the permanent magnets. The salient pole portions are arranged opposite to the armature through a gap such that the magnetic flux generated by the permanent magnets is effected by the magnetic flux passing through the salient pole portions. A direct current excitation coil generates the magnetic flux passing through the salient pole portions. Therefore, an operable speed area of the motor is increased without using demagnetization control and without degrading the efficiency.

Abstract: To estimate nitric acid ions and nitrous acid ions in a sample solution, a method is proposed which comprises the steps of (a) feeding both the sample solution and a reducing agent to an acidic solution which is flowing in a thin pipe; (b) positively mixing the sample solution and the reducing agent and thus reacting the same in a given portion of the pipe; (c) leading the reacted solution to a gas/liquid separator thereby to separate a gaseous phase from the reacted solution; and (d) estimating the nitric acid ions and nitrous acid ions in the gaseous phase.

Abstract: In a digital temperature compensated crystal oscillator, ADC circuit and DAC circuit are combined into a data conversion circuit which comprises a first section for DA conversion, a second section for converting an analog temperature voltage signal into a digital form in cooperation with the first section, and a third section for supplementing the DA conversion of the first section and thereby generating an analog control voltage for a VCO from a digital temperature compensation data. There is further provided a switch circuit for connecting the output of the first section to either of the second and third section.