Applications of Pid controller AI-808

Abstract: This paper introduces the application of intelligent controller AI-808 in temperature control system and the composition and debugging method of the product

Keywords: Intelligent temperature controller, trigger, thyristor, intelligent power regulator

1. Overview

While electric heating equipment are widely used in production, different control methods are also used in various heating automatic control systems. The traditional control method uses a contactor to control the main circuit to perform on-off to achieve the purpose of temperature control. This control method has many disadvantages, the accuracy is not high, and the AC contactor frequently picks up when the set temperature is reached, causing the contacts to burn out or stick together to cause the temperature to be out of control. At the same time, the frequent contact of the AC connector causes fluctuations in the grid voltage and also causes damage to the heating element. It directly affects the economic benefits of enterprises.

In order to overcome the above shortcomings, our company uses the AI series intelligent controller, trigger and bidirectional thyristor produced by Yudian Automation Technology Co., Ltd. to control the temperature.

Intelligent power regulators are widely used in various types of hot rolling mills, electric heaters, electric ovens, drying rooms, hot lighting and other electric heating equipment. The control mode is flexible, the manual automation is convenient, and the temperature control precision is high. The intelligent power regulator mainly consists of intelligent controllerAI-808, thyristor module, trigger, and fast-melting. The system mainly adopts non-contact, which greatly enhances seismic, anti-corrosion and anti-interference ability. It has high stability and reliability, small size, convenient installation and maintenance and has become an new generation of replacement for chemical, textile, food, automobile, electronics and other industries.

2. Temperature control system structure and working principle

The temperature control system consists of air switch, thyristor, trigger and intelligent controllers. The thyristor is mounted on the heat sink, and the exhaust fan. The temperature switch are installed on the heat sink to control the start and stop of the exhaust fan, so as to ensure that the thyristor has good heat dissipation under working conditions without being damaged by overheating.

According to the relevant manual for specific selection, The thyristor is a bidirectional thyristor with varistor or RC absorption protection and fast fuse protection.

The intelligent power regulator is a “zero voltage switch” controller composed of thyristors. When the AC voltage crosses zero, the thyristor is connected to several cycles for a certain period of time, and then several cycles turned off. The purpose of adjusting the load power is achieved by changing the conduction time of the thyristor during the set period. This triggers the thyristor conduction when the voltage crosses zero, so that the load is a completed sine wave. Compared with the phase shifting regulator, it can avoid generating higher harmonics and has less interference to the power grid and other equipment which has higher power factor and efficiency.

The intelligent power regulator adopts the temperature controller AI-808 to form an automatic  closed-loop control system. It adopts embedded system and PID self-tuning function. You can set temperature freely. According to the different types of on-site temperature sensors, the type can be set freely (access thermocouple, thermal resistance and linear voltage, linear current, etc.), and can be set to 0-10V, 1-10mA, 4-20mA as standard output signal . Its output power for voltage and current is proportional. Adjustment mode: It can adopt on-off mode or AI artificial intelligence adjustment, including fuzzy logic PID adjustment and parameter self-tuning algorithm, which can be used for closed-loop or open-loop control, manually adjust the given potentiometer to realize temperature control.

AI-808 artificial intelligence controller also has segmentation power limitation and programming segments. The communication module can work with the upper computer to form a network for data acquisition and multiple temperature control cabinets.

Conditions of Use

Scope of application: capacitive or inductive load

Power supply voltage: three-phase four-wire 380V±10%, 50HZ or single-phase 220V

Ambient temperature: -10℃- +45℃  

3. System debugging and precautions

3.1 Input and output circuit

Check the wiring according to the system schematic diagram, especially if the trigger circuit wiring is correct. The controller should be set correctly before use. Set the input specifications of the controller according to the type of on-site sensor. Different output types can be set depending on the trigger receiving signal.

3.2 False load test

Since there is no actual load, when testing the load, connect the bulb to the output of the main circuit, set manual control mode, press and hold the > or < key to control the brightness of the bulb, and observe whether the brightness of the bulb is dimmed. The change indicates that the trigger circuit wiring and the entire system wiring are correct.

3.3 Manual adjustment and self-tuning of smart meters

In the actual use process, the user controls the temperature according to the process requirements within a certain range. Therefore, the intelligent controller is adjusted, and the fuzzy rule is used for PID adjustment to achieve precise temperature control. With the self-tuning function of the controler, one to two auto-tuning can be set to achieve precise control effects. Different temperature control requirements for different time periods can be programmed to achieve control objectives.

4 Conclusion

The temperature control cabinet produced by the company was put into operation and work well which can fully meets the requirements of users.