Design and Realization of Variable Frequency and Speed Regulation of Motor Experiment System Based on PLC

Based on S7-200 PLC, the variable frequency speed-adjusting experiment system is introduced with the constitution and controlling scheme and signal-disposal methods of this system, and the hardware circuit, related trapezoid chart and displaying program of touch screen is designed as well.The debugging results show that the system is simple and practical.Students can better master the rrinciple and the application of PLC and variable frequency speed-adjusting system through the practice and exercise of general designing experiment or curriculum design. Furthermore, they can also use the touch screen skillfully, which will lay a good foundation for their future design work in this filed. The paper proves to be of high value for reference in the other related research.