Three-phase motor driving control device

Abstract

The invention provides a three-phase motor driving control device, wherein by adopting the simple and cheap configuration the phase failures such as broken lines of the three-phase motor can be detected in a rotating driving of the three-phase motor. When the driving current is provided for the motor by the three-phase inverter circuit in order to rotate the three-phase motor, a control part can be used to detect a DC current across a shunt resistor. When the phase failures such as the broken lines do not exist, six saw-tooth waveform wave crests of the DC current detection signal can occur during one rotating period of the motor. When the phase failure of one phase occurs, the number of the wave crests during one rotating period can be reduced to 2. Therefore the value of the predetermined time and the latest value can be compared, when the current value data, when the current value data of the six wave crests are timely read by the control part, therefore the number of the wave crests can be determined. When the results shows the abnormity, the driving of the three-phase motor can be stopped, and the display can be used for the display of the abnormity.

Description

technical field [0001] The present invention relates to a drive control device for driving a three-phase motor, and more specifically, to a drive control device for a three-phase motor with a disconnection detection function, wherein the disconnection detection function is for the internal wiring of the three-phase motor and the The function of detecting the disconnection of the distribution line between the device and the three-phase motor. Background technique [0002] For example, in a semiconductor manufacturing apparatus such as a sputtering apparatus, a turbomolecular pump is used to create a high vacuum atmosphere in a chamber. In a turbomolecular pump, a three-phase motor capable of high-speed rotation at a maximum of about 800 Hz or higher is used as a pump motor. In such a three-phase motor, when a disconnection occurs in an internal coil or a power distribution line connecting the motor and the drive control device, the motor does not operate and cannot function ...

AI Technical Summary

Problems solved by technology

However, in the above-mentioned turbomolecular pump, since the rotation speed rises rather slowly, it takes time for the rotation speed to rise to a predetermined rotation speed even when the motor is normal.

Therefore, there is a problem that it takes time to obtain the detection result of the presence or absence of a disconnection, and in the case of a disconnection, time is wasted from starting the start to obtaining the result.

[0006] However, in this method, since the three-phase AC drive of the three-phase motor needs to be stopped when the disconnection detection operation is performed, the disconnection detection cannot be continuously performed during the rotation drive of the three-phase motor.

Semiconductor manufacturing equipment using the above-mentioned turbomolecular pump is often operated unmanned, and if an abnormality occurs in the rotation of the motor and the vacuum degree drops during the period when the operator does not notice it, a large loss will occur, so it is necessary to prevent such Countermeasures arising from the situation

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