Application of PLC and the Frequency Conversion Technique to Secondary Pump Control in the Waterworks

This paper mainly introduces how to combine the PLC with the frequency conversion technique in order to control the pumps and the process in the waterworks. According to the characteristic of the frequency conversion technique, some advantage of the method about the control the pump's speed is introduced in paper. We also recite some point and appliance about the SMC. The system succeeds to fulfill the request of the consumer. It do well and make the consumer to satisfy.