Okuma Corporation

Akiyoshi Satake

Masayuki Nashiki

Takeshi Sakai

An electric motor control device for performing tandem control for driving one movable component includes, for each electric motor, a position controller, a speed controller, and a current controller. Further, each electric motor also has a preload controller for adding a preload torque to a torque command Tm calculated by the speed controller, and to a torque command Ts calculated by the speed controller. The preload controller calculates a minimum necessary preload torque for eliminating backlash in accordance with a position of the movable component.

Electric motor control device

A control apparatus for a reluctance type synchronous motor wherein slit-shaped gaps or a nonmagnetic material are included within a rotor to provide level differences of the magnetic reluctance in a rotating direction, and a permanent magnet is included at a portion of the slit-shaped gaps or the nonmagnetic material to provide magnetic polarities at a rotor surface. The control apparatus includes a q-axis current calculation unit, a d-axis current calculation unit, a speed coefficient calculation unit, a q-axis current compensation value calculation unit, and an output unit which outputs a compensated q-axis current command value in which the calculated q-axis current compensation value is added to the q-axis current command value.

Control apparatus for reluctance type synchronous motor

A controller for a reluctance type synchronous motor. When field current control depends solely on a rotor speed, large power consumption and heat generation of a motor may be caused. Also, when a field current is small, torque consumption becomes small, resulting in a prolonged acceleration time. To address the above problems, there is provided a section for generating a field current command SIFC using a field current compensation coefficient SKF having been obtained based on a torque command STC. With this arrangement, a large field current SIFC flows when a torque is needed, and a small field current SIFC flows when torque is not needed. There is also provided a section for generating an armature current command SIAC using armature current command compensation SKA having been obtained based on a field current command SIFC. With this arrangement, variation of a torque constant due to variation of a field current is converted into an armature current command SIAC based on a field current command SIFC.

Controller for reluctance type synchronous motor

In an armature current limit value calculator section, limitation is applied to a pre-limitation torque command ST in correspondence with a presently detected speed SPD, to calculate a torque command STC. Meanwhile, in a field current calculator section 12, a pre-correction field current command value SF is decreased in correspondence with the detected speed SPD when the speed is large. In addition, a coefficient K.tau. which increases when the torque command is large is calculated on the basis of the pre-limitation torque command ST at this time. Further, a field current command is calculated from an equation SFC=K.tau.*SF. A current command calculator section 3 prepares a current command on the basis of the torque command STC and the field current command SFC supplied, and drives an electric motor 5 via a current control section 4.

Control device for a reluctance type synchronous motor

A reluctance type synchronous motor comprises: a stator with a plurality of slots placed at an even pitch angle wherein stored inside each slot is a stator winding for creating stator magnetic poles with a predetermined phase alternating current being supplied thereto. A rotor sustained by a shaft and changing magnetic reluctance in its circumferential direction by inclusion inside of a plurality of magnetic isolating portions creates desired magnetic poles. At least one of the central angles between magnetic poles created at the rotor is shifted from the other central angles so that torque ripples during rotation can be reduced.

Reluctance type synchronous motor

High permeability material plates used to construct the stators and the rotor of a motor are formed of the same material, thus reducing the number of fabrication processes and material cost. Also, the rotor containing permanent magnets is cylindrical and two stators are arranged around the inner circumference and the outer circumference of the permanent magnets, respectively, thereby increasing efficiency.

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Niwa-gun, Japan

Akiyoshi Satake