Using the servo amplifier module should pay attention to the regulation of the problem Zhang News (Hunan thermal power construction company debugging Yiyang, 413000) CLC number: TP273 Document code: B • Preface The use of computer distributed control system that is to achieve the DCS The whole process of monitoring and control is an inevitable trend. The DCS system has utilized the mature "4C" technology today to achieve an unprecedented level of automation in industrial production. Its sound management and control capabilities enable the production process Surveillance and control become very easy. It replaces the original complex conventional control methods, greatly reducing the number of devices, but also make our installation and debugging to reduce the workload. But it also brings us some new problems that need our attention in the installation and debugging. Such as automatic control loop actuator control, when using the servo amplifier module to replace the proportional control panel or servo amplifier, we should pay attention to due to improper installation and parameter setting actuator in the process of oscillation problems. • PROBLEM PROBLEMS In the case of an automatic control circuit, actuators with proportional control boards or servo amplifiers should always be used if an electric actuator is used. Of course, in the DCS control algorithm function module, also has a proportional control board function servo module, you can use it instead of proportional control board or servo amplifier. In my company's construction of a paper mill in Guangdong's own power plant project, is to adopt this approach. However, during the commissioning process, we found that when we step-change the control output by more than 5%, the induced draft fan inlet damper damper will oscillate. In order to restrain the actuator oscillation, we adjust the action dead Later, we found that because the change of the opening of the induced draft damper has a great influence on the pressure in the furnace, the dynamic characteristics of the furnace pressure are poor, which makes the furnace pressure fluctuate violently during the operation of adjusting the pressure of the furnace. , Easily cause the fire extinguishing chamber, affecting the operation of the safety, so we must take measures to solve this problem. • Analysis of the problem For the phenomenon of oscillation during the operation of the actuator, we carefully examined and analyzed the equipment itself, the performance of the functional module and the configuration parameters, the performance of the baffle and the installation of the actuator. (1) Actuator oscillation, nothing more than because in the operation process, due to the control signal and position feedback signal can not be caused by the balance. In the case of the control loop, the controller output is independent of the process instability and the output signal is not controlled by the regulator when in manual mode of operation, so the control signal is stable. This shows that only the actuator position feedback signal fluctuations or inconsistent control and feedback caused the actuator oscillation. (2) From the influencing factors of instability of actuator position feedback signal, firstly, the instability of the adjusting mechanism itself and the slight vibration of the mechanism lead to a slight fluctuation of the position feedback of the actuator; secondly, due to the external force Or friction caused by the unbalanced resistance, making the actuator instability in the operation of the phenomenon prone to actuator over; Phenomenon resulting in oscillation; Third, the position feedback circuit itself is caused by instability, such as the position feedback device Of the load capacity does not work, does not match with the external device, the position feedback device has low anti-interference ability is the cause of the feedback signal instability; Fourth, the signal transmission line noise introduced by the introduction of the feedback signal into and out there Interference signal.