Abstract: A voltage drop Vzs is calculated based on an output current detection value Iac and a virtual synchronous impedance Zs or a corrected virtual synchronous impedance Zs?, and a value obtained by subtracting the voltage drop Vzs from an internal induced voltage Ef is output as a grid voltage command value Vac*. Zs calculation unit 7 limits an output current phase ? so that the output current phase ? is within an effective range by a phase limiter 12a, and calculates the corrected virtual synchronous impedance Zs? based on a limited output current phase ?, the internal induced voltage Ef, a grid voltage detection value Vac and a current limit value Ilim. Accordingly, in grid interconnection power conversion device that controls a virtual synchronous generator, it is possible to continue operation while suppressing an overcurrent and possess a synchronizing power generated by action or working of a virtual synchronous impedance.

Abstract: Between positive and negative electrode ends of battery 50, fuse 51, main contactor 52 and electrolytic capacitor C21 are connected in series. Between positive and negative electrode ends of electrolytic capacitor C21, inverter 54 in which upper phase side EFT (54U, 54V, 54W) and lower phase side FET (54X, 54Y, 54Z) are bridge-connected is connected. Resistor R1 for precharging electrolytic capacitor C21 is connected to main contactor 52 in parallel. The resistance value of resistor R1 is set so that in a precharging period until a key switch is turned on after battery 50 is connected, when the upper phase side FET is OFF-controlled and the lower phase side EFT is ON-controlled, the charge voltage value of electrolytic capacitor C21 is set to be able to limit a gate-source voltage of the upper phase side FET to a voltage at which the upper phase side FET is not turned on.

Abstract: A pulse voltage generator calculates a corrected pulse voltage application time. The pulse voltage generator also outputs, for the duration of the corrected pulse voltage application time, a voltage vector closest to a rotor phase from among twelve voltage vectors as a voltage vector command. A current detector detects three-phase output currents of a power converter, which are obtained when first to sixth switching elements of the power converter are turned on or off on the basis of the voltage vector command. A three-phase/two-phase converter converts the three-phase output currents to two-phase output currents to output d-axis current. When the d-axis current after the corrected pulse voltage application time has elapsed becomes less than or equal to a demagnetization determination threshold value, a demagnetization determiner determines that demagnetization occurs in a permanent magnet of a rotor of a motor.

Abstract: A vehicle system vibration suppression control device is provided for a vehicle system in which a vehicle is driven via an elastic shaft by a motor drive device having a torque control function. The vehicle system vibration suppression control device includes: a section containing an approximate model to which an output torque command is inputted; and a feedback control section. The feedback control section is configured to: employ the approximate model; calculate a motor-accelerating torque component by differentiating a measured speed component of a motor rotational speed; produce a compensation torque component by causing the motor-accelerating torque component to pass through a vibration suppression control filter; and calculate the output torque command by subtracting the compensation torque component from an input torque command. The vibration suppression control filter is expressed by a second order mathematical expression.

Abstract: In a vacuum container (1) of a vacuum interrupter (1A), an insulating cylindrical body (10) is sealed with a fixed-side flange (11a) on the fixed side in the axial direction, and is sealed with a movable-side flange (11b) on the movable side in the axial direction. In the fixed-side flange (11a) and the movable-side flange (11b), annular expansion portions (5a, 5b) are formed between middle portions (3a, 3b) and outer peripheral edge portions (4a, 4b), respectively. The annular expansion portions (5a, 5b) are respectively formed in annular shapes extending along the outer peripheries of the middle portions (3a, 3b), and in shapes expanding in the axial outer side direction of the vacuum container (1), such that an arch structural effect can be obtained.

Abstract: A vehicle inspection device for an inspection implemented with a tire of a vehicle idling includes a tire supporter. The tire supporter includes rollers structured to allow the tire to idle; a housing supporting the rollers so as to allow the rollers to rotate; a stopper contained in the housing and structured to move up and down and butt into the tire disposed on the rollers; and a link mechanism structured to elevate the stopper. The vehicle inspection device is structured to be disposed on a plane that allows the vehicle to run thereon.

Abstract: In a cylindrical guard electrode (5) provided on the outer peripheral side of an electron generation part (31) of an emitter (3), a distal end section (5A) 5 positioned in the emission direction of an electron beam (L1) from the electron generation part (31) includes: a distal end inner-peripheral-side part (A1) having an inner-peripheral-side curved surface portion (a1) convex in the emission direction; a distal end outer-peripheral-side part (A2) having an outer-peripheral-side curved portion (a2) convex in the emission direction; and a 10 distal end middle part (A3) positioned between the distal end inner-peripheral-side (A1) and the distal end outer-peripheral-side part (A2). The distal end middle part (A3) has a flat surface portion (a3) between the inner-peripheral-surface portion (a1) and the outer-peripheral-side curved surface portion (a2) so as to extend in the direction therebetween.

Abstract: This vehicle speed command generation device 1 generates a target vehicle speed command to be used by a vehicle speed control device. The vehicle speed command generation device 1 comprises: a shift processing unit 12 that receives an original vehicle speed command and generates each of a reference vehicle speed command in which the original vehicle speed command is delayed by a reference delay time, a first-out vehicle speed command in which the original vehicle speed command is delayed by a first-out delay time that is shorter than the reference delay time, and a delayed vehicle speed command in which the original vehicle speed command is delayed by a second delay time that is longer than the reference delay time; and a correction processing unit 16 that generates a target vehicle speed command by using the first-out vehicle speed command and the delayed vehicle speed command.

Abstract: This system identification method includes: a step (S1) for measuring frequency responses (?, HR1), (?, HR2) . . . , and (?, HRn) in a real system under n sets of disturbances of different magnitudes; a step (S3) for calculating frequency responses (?, HM1), (?, HM2) . . . , (?, HMn) from input to output in n sets of mechanical models M1 to Mn including i sets (i is an integer of 1 or greater) of common parameters that do not change due to disturbance and j sets of disturbance variable parameters that do change due to disturbance; a step (S4) for calculating the values of a total of n sets of evaluation functions F (HRk, HMk) and the sum ?F thereof, and steps (S3 to S6) for searching for the values of i sets of common parameters and j×n sets of disturbance variable parameters for which the sum ?F would meet convergence conditions.

Abstract: A bubble generation device is provided which is capable of discharging bubbles of about the same size from each of a plurality of bubble discharge ports. The device is provided with a bubble discharge chamber communicating with each of a plurality of bubble discharge ports, a turnaround path including a first communication port communicating with a gas storage chamber and a second communication port communicating with the bubble discharge chamber on a downstream side in a gas traveling direction of a turn-around point of the turnaround path, opening areas of the plurality of bubble discharge ports being the same as each other, and a total of the opening areas of the plurality of bubble discharge ports being smaller than an opening area of the second communication port.

Abstract: A vacuum interrupter is equipped with a vacuum container and fixed and movable electrodes provided in the vacuum container. The vacuum container is constructed by hermetically respectively joining fixed-side and movable-side end plates to one and the other end portions of an insulating tube. The insulating tube is equipped at its end portion with a projection portion that projects in an axial direction of the insulating tube along an outer periphery of the insulating tube. The insulating tube is equipped at its end portion with an end plate joining portion that projects from a base end portion of the projection portion inwardly in a radial direction of the insulating tube. The end plate joining portion is equipped on its surface with a metallized layer to which the fixed-side or movable-side end plate is joined by brazing.

Abstract: The present invention relates to a rotating machine and a hoist. An object of the present invention is to provide a rotating machine and a hoist with improved cooling performance. A motor (10) includes: a stator (11) and a rotor (12); a rib part (12d) that rotates in accordance with rotation of the rotor (12), and a wind guide member (16) that guides wind taken in from a ventilation inlet (15aa) by rotation of the rib part 12d to a ventilation outlet (15ab).

Abstract: Power conversion device has first position/rotation detector 14, second position/rotation detector 15 whose resolution per rotation of motor is higher than the first position/rotation detector 14 but whose detection cycle is slower than the first position/rotation detector 14 and encoder switching operation process unit 18. The encoder switching operation process unit 18 switches signals between the first and second position/rotation detectors 14, 15 and outputs the signal of the first position/rotation detector 14 or of the second position/rotation detector 15, or adjusts a ratio of the signal between the first and second position/rotation detectors 14, 15 and output a signal obtained by adding adjusted signals. With this, in the power conversion device, the encoder having high resolution and slow detection time and the encoder having low resolution and fast detection time are properly used according to rotation speed, and current and the rotation speed are controlled with high accuracy.

Abstract: This test system comprises: a dynamometer connected to a test piece W; an inverter for supplying electric power to the dynamometer; an encoder for generating a speed detection signal N corresponding to a rotational speed of the dynamometer; and a dynamometer control device 6 for generating a torque current command signal DYref. The dynamometer control device 6 comprises: a response model 61 that receives a higher-order speed command signal Nr and outputs a model speed command signal Nr?; a feedforward controller 62 that receives the higher-order speed command signal Nr and outputs a feedforward input uff; and a speed controller 64 that generates the torque current command signal DYref on the basis of a feedback input ufb generated on the basis of a deviation e between the model speed command signal Nr? and the speed detection signal N, and the feedforward input uff.

Abstract: An arc shield surrounding an outer peripheral side of a fixed electrode and a movable electrode is provided, in addition to a fixed-side insulating unit in which a fixed-side insulator is provided to be connected coaxially with the arc shield on the fixed side in the axial direction of the arc shield, and a movable-side insulating unit in which movable-side insulators are provided to be connected coaxially with the arc shield on the movable side in the axial direction of the arc shield. The movable-side insulating unit has an insulator group in which movable-side insulators are provided to be connected in the axial direction, an insulator-group-side sub shield surrounding the outer peripheral side of a movable-side energizing shaft, and an insulator-group-side sub shield support part which is on the outer peripheral surface of the insulator-group-side sub shield and interposed between two adjacent movable-side insulators of the insulator group.

Abstract: The motor includes a sealing material (dry body of a liquid gasket 41) interposed between a joint surface 3b of a motor housing 3 and a joint surface of an inverter housing, and an O-ring 39. The O-ring 39 is interposed between the motor housing 3 and the inverter housing and disposed so as to surround the communication port 3a1 of the refrigerant flow path 3a. The motor housing 3 includes a groove 3d disposed between the sealing material and the O-ring 39 on the joint surface 3b in a surface direction of the joint surface 3b.

Abstract: Power conversion device has first position/rotation detector 14, second position/rotation detector 15 whose resolution per rotation of motor is higher than the first position/rotation detector 14 but whose detection cycle is slower than the first position/rotation detector 14 and encoder switching operation process unit 18. The encoder switching operation process unit 18 switches signals between the first and second position/rotation detectors 14, 15 and outputs the signal of the first position/rotation detector 14 or of the second position/rotation detector 15, or adjusts a ratio of the signal between the first and second position/rotation detectors 14, 15 and output a signal obtained by adding adjusted signals. With this, in the power conversion device, the encoder having high resolution and slow detection time and the encoder having low resolution and fast detection time are properly used according to rotation speed, and current and the rotation speed are controlled with high accuracy.

Abstract: A vehicle system vibration suppression control device is provided for a vehicle system in which a vehicle is driven via an elastic shaft by a motor drive device having a torque control function. The vehicle system vibration suppression control device includes: a section containing an approximate model to which an output torque command is inputted; and a feedback control section. The feedback control section is configured to: employ the approximate model; calculate a motor-accelerating torque component by differentiating a measured speed component of a motor rotational speed; produce a compensation torque component by causing the motor-accelerating torque component to pass through a vibration suppression control filter; and calculate the output torque command by subtracting the compensation torque component from an input torque command. The vibration suppression control filter is expressed by a second order mathematical expression.