Frequency conversion type intelligent type valve actuator

Abstract

The invention relates to frequency conversion intelligent valve executing mechanism, comprising a main controller module 1, a vector frequency conversion control module 2, an asynchronous motor 3, a mechanical transmission device 4, a multi-circle precision rotating potentialmeter 5, a display module 6, and a handy operator 7. The invention is mainly characterized in that: the asynchronous motor is driven by the vector frequency conversion control module, and the precision rotating potentialmeter is used as a position sensor, to control the valve position by adopting whole digital proportional close-loop regulation type, and the control type comprises a plurality of control modes such as local remote control operation, handy operator control, long distance analog control, and bus control, etc, and a low temperature-rise special frequency conversion motor. The invention has the advantages of small size, high reliability, high positioning precision, having servo control characteristics, and easy networked control, etc. Compared with traditional executing mechanism, the invention greatly enhances the positioning precision, can continuously work for a long time, and automatically adapt to the working condition of single phase or three phase DC power.

Description

(1) Technical field [0001] The invention relates to a valve actuator, in particular to a variable frequency intelligent valve actuator. (2) Background technology [0002] At present, the valve actuators widely used all use three-phase AC voltage to directly drive the motor, and drive the valve to run through the mechanical transmission device. The phenomenon of multi-cycle damping oscillation occurs during positioning, which greatly reduces the positioning accuracy of the actuator to the valve. In addition, because the starting current of the motor is several times the rated current, the temperature rise of the motor rises sharply, and it cannot operate continuously and frequently for a long time. In addition, the existing actuators all use three-phase AC motors, and their application is greatly limited for sites that do not have a three-phase AC grid. [0003] On the other hand, most of the valve position detection methods of existing actuators use gear transmission, count...

AI Technical Summary

Problems solved by technology

[0002] At present, the valve actuators widely used all use three-phase AC voltage to directly drive the motor, and drive the valve to run through the mechanical transmission device. The multi-cycle damping oscillation phenomenon occurs during positioning, which greatly reduces the positioning accuracy of the actuator to the valve. In addition, because the starting current of the motor is several times the rated current, the temperature rise of the motor rises sharply, and it cannot operate continuously and frequently for a long time.

In addition, the existing actuators all use three-phase AC motors, and their application is greatly limited for sites that do not have a three-phase AC grid

[0003] On the other hand, most of the valve position detection methods of existing actuators use gear transmission, counter amplification, and then output through potentiometers, cams and contacts. After such a complicated electromechanical process, its accuracy will be greatly distorted. , cannot achieve high-precision measurement. In addition, due to the limitation of the number of mechanical contacts on the cam, the output detection value can only be an intermittent analog signal, which cannot achieve full-stroke high-precision position control.

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