Motor control device and work machine using same

Abstract

The purpose of the present invention is to provide a motor control device that can compensate even for errors in motor constant settings and that is capable of high-precision torque control. A motor control device (100) comprises a control unit that controls the current supplied to a motor so that a current command value determined on the basis of a torque command value for a motor (MOT) matches a detected current value for current supplied to the motor (MOT) by way of a power converter (INV). The control unit estimates the torque output by the motor and controls the current supplied to the motor so that the estimated value for the torque of the motor matches the torque command value. A torque estimation computation unit (120) estimates the torque output by the motor. A phase error command computation unit (125) calculates a command value for phase error on the basis of the deviation between the estimated torque value and the torque command value. A speed estimation computation unit (130) outputs an estimated speed value so that an estimated phase error value matches the command value for phase error.

Description

technical field [0001] The present invention relates to a motor control device and an operating machine using the motor control device, in particular to a motor control device suitable for torque control of a permanent magnet synchronous motor and an operating machine using the motor control device. Background technique [0002] Conventionally, among the motor control devices that perform torque control, there is known a device that has a motor constant calculation unit that calculates the electric constant of the motor, and uses one of two orthogonal axes (d-axis and q-axis) The setting value of the electrical constant defined by the axis is corrected by using the relational expression of the state variable defined by the same axis, and by using the relational expression of the state variable defined by the other axis (For example, refer to Patent Document 1). [0003] According to the above aspect, the electrical constant of the permanent magnet synchronous motor can be s...

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Problems solved by technology

[0006] However, in the motor control device described in Patent Document 1, there is no concern about the setting error of the motor constant, etc.

If there is a setting error of the motor constant, the accuracy of torque control will decrease by the amount corresponding to the error

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