基于PLC的恒压供水系统设计及实现-毕业论文

Based on PLC frequency conversion constant pressure water supply system, and develops a good operation management interface using configuration software. The variable frequency constant pressure water supply system consists of programmable controllers, frequency converters, water pump units, pressure sensors, industrial computers, etc. This system includes three water pump motors, which operate in a variable frequency cycle mode. The frequency converter is used to achieve soft startup and frequency conversion control of the three-phase water pump motor, and the running switching adopts the principle of "start first, stop first". The pressure sensor detects the current water pressure signal, sends it to the PLC for comparison with the set value, and performs PID operation to control the output voltage and frequency of the frequency converter, thereby changing the speed of the water pump motor to adjust the water supply volume, ultimately maintaining the pipeline pressure stable near the set value. Through the connection between the industrial computer and the PLC, the configuration software completes the system monitoring, realizing dynamic display of operation status, and querying of data and alarms. Keywords: frequency conversion control, constant pressure water supply, PLC, configuration software.