Motor control device and pole position estimation method

Abstract

The present invention provides a motor control device and a magnetic pole position estimation method capable of easily estimating the initial magnetic pole position of the rotor even when the rotor of the motor is rotating. A motor control device according to an embodiment includes a power conversion unit and a control unit. The power conversion unit supplies power to the motor having salient polarity. The control unit performs proportional-integral control on a deviation between the current command and the current flowing through the motor to generate a voltage command, and controls the power conversion unit based on the voltage command. Furthermore, the control unit estimates the magnetic pole position of the rotor of the motor by controlling the power conversion unit so that a high-frequency current flows through the motor, and corrects the estimated magnetic pole position based on the integral value of the proportional-integral control.

Description

technical field [0001] The disclosed embodiments of the present invention relate to a motor control device and a magnetic pole position estimation method. Background technique [0002] When starting a motor such as a permanent magnet synchronous motor, if the magnetic pole position of the rotor is different from the control phase, vibration will occur at the start, and it may also rotate in the direction opposite to the commanded direction. Therefore, in the conventional motor control device, when the motor is started, an initial magnetic pole position estimation process of estimating the initial magnetic pole position of the rotor using the saliency and magnetic saturation characteristics of the motor is performed. [0003] In this initial magnetic pole position estimating process, after provisionally estimating the magnetic pole position of the rotor, the magnetic pole position of the rotor is formally estimated as the initial magnetic pole position based on the polarity (...

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Problems solved by technology

[0007] However, when current control is performed while applying a pulse voltage to determine polarity, the difference in current change due to magnetic saturation of the d-axis magnetic flux becomes smaller due to the influence of current control, and the accuracy of polarity determination deteriorates.

Therefore, it is necessary to use a band-pass filter so that the bandwidth of the pulse voltage will not be affected by the current control, or to expand the amplitude of the pulse voltage, which will lead to the complexity of the circuit and the high voltage of the pulse voltage.

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