Intelligent integrated electric actuatorWith the rapid development of microelectronics, computer, communication network technology and electromechanical integration technology, intelligent electric actuators have appeared in the world since 1990s. It is a new type of intelligent terminal actuator with microprocessor. Since then, intellectualization has become the general trend of actuator development. It is necessary to know the development status of intelligent electric actuator as soon as possible.

　　Intelligent Electric Actuator and Its Characteristics

　　In recent years, electric actuators have developed rapidly, and some manufacturers at home and abroad have introduced intelligent electric actuators with fieldbus communication protocol. The new intelligent electric actuator integrates servo amplifier and actuator by means of computer and fieldbus communication technology. It not only realizes the functions of bidirectional communication, PID regulation, on-line automatic calibration, self-calibration and self-diagnosis, but also adds travel protection, over-moment protection and motor overheating. Protection, power failure signal protection, output field valve position indication and fault alarm functions. It can perform field operation or remote operation, complete manual operation and manual/automatic undisturbed switching.

　　Intelligent electric actuator adopts novel structural components. The microprocessor system is used in the servo amplifier. All the control functions can be realized by editing. It also has a digital communication interface, so it has HART protocol or fieldbus communication function and becomes a node in the fieldbus control system. Some servo amplifiers also use frequency converter technology, which can control the servo motor more effectively. The reducer adopts a novel transmission structure with smooth operation, high transmission efficiency, no crawling and low friction. New technologies and new methods are used in position transmitters, some of which use Hall effect sensors to directly induce the longitudinal or rotational action of the valve stem to realize non-contact positioning detection; some use special potentiometers, which contain resistance sheets made of ball bearings and special conductive materials; some use non-connection of magnetoresistance effect. Touch rotary angle sensor.

　　Intelligent electric actuators usually have LCD and manual operation buttons, which are used to display various status information, input configuration data and manual operation.

　　Compared with traditional electric actuators, intelligent electric actuators have the following characteristics.

　?。?）The main parameters and technical indicators are advanced, such as dead zone, basic error and backlash, which have reached or approached the world advanced level, exceeding the existing DDZ-II and III electric actuators in China.

　　（2）Using advanced computer and digital display technology, intelligent servo amplifier instead of traditional servo amplifier and digital operator instead of analog pointer operator, the problem of eye fatigue caused by frequent pulsation of digital display is solved.

　　（3）It has the functions of self-diagnosis, self-adjustment and PI regulation. In particular, the PI regulation function can eliminate the front regulator and directly accept the transmitter signal.

　?。?）Software modification of flow characteristics was added. After using the microprocessor, the flow characteristics can be set and changed flexibly, and the control performance of the control valve can be improved. The control valve with an inherent characteristic can have multiple output characteristics. The valve without core shape correction (butterfly valve) can also change the flow characteristics, and the non-standard characteristics can be modified to the standard characteristics. The function will be changed. Changing the status quo of flow characteristic correction by valve core processing for a long time.

　?。?）Electric brake and intermittent regulation technology are used in the regulation. The mechanical friction brake can be cancelled for the executive mechanism with self-locking function, which improves the reliability of the whole machine.

　?。?）The design of three-phase amplifier adopts a combination scheme with single-phase intelligent servo amplifier and three-phase power converter, which facilitates production and material preparation, and makes it possible for the control room not to control three-phase power supply.

　　Development Trend of Intelligent Electric Actuator

　　The development trend of intelligent electric actuator can be summarized as follows: Mechatronics structure gradually replaces combination structure, intelligent control technology gradually replaces pure electronic control technology, communication technology function gradually replaces non-communication technology, digital control method gradually replaces traditional analog control method and infrared remote control method. Controlled non-contact debugging technology gradually replaces contact manual debugging technology, and so on.

　　When the intelligent electric actuator is connected with the field bus, the intelligent actuator becomes a field instrument in the field bus control system (F). At this time, it not only has the function of actuator, but also has the functions of control, operation and communication. It can be seen that the new generation of intelligent electric actuator products conforming to fieldbus in China is the inevitable trend of the future development of the actuator. Its successful research and application lay a good foundation for the further development of the electric actuator, and will bring broad market prospects for the development of the intelligent electric actuator.