SU1448380A1 - Method of controlling multiphase synchronous motor in positioning mode - Google Patents

Abstract

The invention relates to electrical engineering and can be used to control the actuators of automatic systems and robots. The purpose of the invention is to improve positioning accuracy. Two phases 3 and 4 of the synchronous motor 5 alternately apply pulses of constant polarity, which have either a different amplitude or a different duration, which is determined by the performance of modulator 2. The frequency of the generator 1 is chosen at which the moment of friction in the engine mounts has the lowest value. 3 il. S (L with

Description

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The invention relates to the control of electrical machines and can be used to control the actuators of automatic systems and robots.

The purpose of the invention is to improve positioning accuracy.

Fig. 1 shows a schematic diagram of an apparatus for carrying out the proposed method; Fig. 2 shows time diagrams with a change in the amplitude of pulses of constant polarity; on fig.Z - time diagrams. the change in the duty cycle of pulses of constant polarity.

The device contains a generator of 1 pulses of adjustable frequency, a modulator of 2 pulses, the direct and inverse outputs of which are connected to two phases 3 and 4 of engine 5,

The modulator 2 pulses can be either amplitude with the specification of a different amplitude on the direct and inverse outputs, or a pulse width pulse modulator with switching voltage on the direct and inverse outputs. The method is as follows.

From the pulse generator 1, the signal goes to the pulse modulator 2, in which amplitude or pulse width modulation of the signal is carried out. From the outputs of the modulator 2 to the phases 3 and 4 of the synchronous motor 5 alternate pulses of a constant voltage U and U, respectively. A constant voltage may be applied to the third phase. This excites angular oscillations of the shaft of the engine 5. Change the frequency of the generator 1 and, measuring the moment of friction in the engine mounts 5, determine the frequency at which this moment is minimal. This frequency is fixed. Then the difference in mean values is changed.

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winding currents (3 and 4) by changing the amplitude of the DC voltage pulses or their duty ratio. Due to the inertia of the shaft 5 is discretely rotated at a given angle with a small moment of friction. This significantly reduces the moment of resistance by about 60% relative to the static moment of resistance. Thus, non-linearity of the type of dry friction is eliminated. This allows for improved positioning accuracy of the synchronous motor shaft. The residual shaft oscillations in the set-up mode are much smaller than the required positioning error.

Held control of the synchronous motor brand СД10-У42. At frequency i, 5 kHz, positioning was provided in the range of 0-90 with an accuracy of 5. Such accuracy is unattainable for the base object and the prototype.

The advantage of the proposed method is the ease of implementation, since a serial synchronous motor can be used. The range of angular displacements is determined by the engine design and is usually limited to 90. The proposed method can be widely used in the following systems of technological machines and robots.

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Claims (1)

35 claims The control method of a multi-phase synchronous motor in positioning mode, including the supply of two phases alternately with pulses of constant polarity, characterized in that, in order to improve positioning accuracy, the pulses are supplied to the phases with a frequency corresponding to the lowest friction moment in supports. and, Ui Ui ot Jl FIG, g Jl GP Fig.Z