Mitsubishi Electric Corporation

Ando Electric Company

Nippon Telegraph and Telephone Corporation

Shoji Adachi

Shinichi Furutani

Yasushi Sato

Tetsuya Kojima

Yoshihiko Kinpara

Nobuaki Takeuchi

Toshio Kurashima

Yosuke Hachiya

Kaoru Shimizu

Ryoji Handa

Atsushi Kudo

Takuya Hosoda

Zhixien Li

A motor iron-loss calculation device calculates an iron-loss value of a motor on the basis of a primary frequency and a q-axis current component in a dq-axis rotating coordinate system having a d axis in a rotor magnetic flux direction of the motor.

Motor iron-loss calculation device and motor control device comprising same

A motor inductance measurement device comprises an energization control circuitry to perform energization control of the motor such that an AC voltage is applied to at least one axis on two-axis orthogonal rotation coordinates of the motor to cause the AC current to flow, and an inductance calculation circuitry to generate the characteristic regarding the instantaneous value of the AC magnetic flux corresponding to the instantaneous value of the AC current as the inductance information by calculating the instantaneous value of the AC magnetic flux by integrating a residual voltage which is obtained by subtracting a resistance voltage from the AC voltage, the resistance voltage being obtained from the AC current based on a detection current detected from the motor, and from resistances of the motor.

Motor inductance measurement device, motor drive system, and motor inductance measurement method

[Problem] For measuring the inductance of a synchronous motor, a high-speed and convenient inductance measuring device for a synchronous motor is provided. [Solution] A three-phase high-frequency rotation voltage is applied to a synchronous motor, thereby calculating the inductance from the same frequency component as that of the high-frequency voltage included in a motor current.

Inductance measuring device and measuring method for synchronous motor

A control device for rotary machine includes: a voltage instruction generation section for generating a voltage instruction; a voltage application section for applying voltage to a rotary machine based on the voltage instruction; a current detection section for detecting rotary machine current of the rotary machine; and an inductance calculation section for calculating an inductance of the rotary machine from the voltage instruction and the rotary machine current. The voltage instruction generation section generates voltage instructions of constant DC voltages. The voltage application section applies voltages to the rotary machine based on the voltage instructions. The inductance calculation section calculates the inductance from a voltage instruction for measurement arbitrarily selected from the voltage instructions, and the rotary machine currents detected by the current detection section before and after application of the voltage instruction for measurement.

Control device for rotary machine and inductance measurement method for rotary machine

Coherent light emitted from a coherent light source 1 is sent as a probe beam through a connector 31 into an optical fiber being measured. A portion of this beam is sent to an optical frequency converter 100 to form an optical pulse train having a frequency which is frequency-swept in steps of a designated frequency at a designated periodicity, and an optical pulse having a designated frequency is extracted from the optical pulse train by an electro-optic switch 18 and sent to the optical fiber being measured. Then, a signal beam exiting the optical fiber being measured is heterodyne-received by means of a local beam passing through either a connecting optical fiber 6 side or a frequency shifter 7 side according to the selection of optical switches 4 and 5. Consequently, it is possible to measure the characteristics of the optical fiber by means of a BOTDR, BOTDA or a COTDR.

Optical fiber characteristic measuring device

A high-power light pulse generating apparatus in which an optical fiber doped with a rare earth element is used in an optical system for facilitating control and and adjustment of the apparatus. The light output power and the pulse width thereof can be varied simply by changing the characteristics and the length of the optical fiber. In the high-power light pulse generating apparatus, an output of an optical pumping light source (2) is inputted to an optical coupler (3) which constitutes an optical loop in cooperation with the optical fiber (1) doped with a rare earth element, an optical decoupler(4), an optical switch (5A), an isolator (7) and an input port of the optical coupler (3). By turning on the optical switch (5A), a high-power light pulse can be generated through the optical loop and extracted from an output port of the optical decoupler (4).

High-power light pulse generating apparatus

An apparatus for measuring a radiation characteristic of a laser diode. An AC signal and a step-like DC voltage are applied to the laser diode and the radiant power output thereof is received by a photodiode having an output to which a first amplifier, a transformer, a capacitor and an AC amplifier for extracting the AC signal. The apparatus further comprises a first switch connected between the input of the first amplifier and the capacitor, and a second switch connected between both ends of the transformer. Every time the step-like voltage is stepped up, the first and second switches are closed for a short time as compared with the duration of a step period to protect the measurement from the influence of the change in the DC voltage.

Growing community of inventors

Tokyo, Japan

Shoji Adachi