Synchro motor drive device

Abstract

The invention provides a synchronous electromotor driving device which smoothly starts an acceleration synchronous electromotor without speed and a position speed, and restrains reversion. The synchronous electromotor driving device of the invention controls magnitude, frequency, phase of an output voltage, addes a gived phase corrected value to the phase when a synchronous electromotor is started, modifies the phase corrected value more than once, and corrects the frequency or phase based on a detection value of an output current. In addition, when the phase corrected value is modified, the phase is increased at a positive rotation direction of the electromotor, for example, gradually incresed to lower than 90 degrees. Morever, when the gived phase corrected value initially modified, a time setting an initial phase corrected value is shorter than a time setting a modified phase corrected value.

Description

technical field

[0001] The present invention relates to a motor drive device for variable-speed operation of a synchronous motor, in particular to a motor drive device for starting and accelerating a synchronous motor without using speed and position sensors. Background technique

[0002] In the speed and position sensorless control of synchronous motors, there has been a kind of superimposed high-order harmonics on the output current or output voltage, using the inductance in the magnetic flux axis (d axis) and the axis (q axis) perpendicular to the magnetic flux axis The difference between (Ld, Lq) is used to detect the speed or magnetic pole position. FIG. 10 shows the technology of Patent Document 1 as a conventional technology. In addition, although the synchronous motor in FIG. 10 is a permanent magnet type synchronous motor, the operation is the same if a winding type synchronous motor with a magnetic field device is used. In the speed control unit 103, the speed co...

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