The Research On Development Of Hydraulic Turbine Governor Based On FX_2N PLC

Microprocessor-Based governor is the important device in the hydraulic turbine control system. In recent years, the PLC technology has been widely applied in this field. The paper uses the FX2N PLC of Mitsubishi Electric Corporation to realize the basic function of turbine governor, and also analyzes the hardware and software of this system detailedly.The following points are specially researched:1. According to the self-characteristic of PLC, this paper designs a circuitry for the frequency measurement.2.Several rules in opening process are analyzed and compared. Based on the open loop rule, this paper also gives a way of opening process, which uses the extraction of square root of the increment. It can start the hydroelectric generating unit quickly and smoothly.3.This paper analyzes the process of parallel PID discretization. An improved PID algorithm is adopted to realize a PID regulation mode with variable structure and parameters.4.The communication mechanism of PLC is specially studied. The different method of serial communication by using MSComm control and Win API is analyzed and compared. Furthermore, the paper develops a monitor and manager program for the communication between PLC and upper PC.