Abstract : Constant pressure water supply speed regulation systems achieve stepless speed regulation of water pump motors, automatically adjusting system operating parameters based on changes in water consumption (actually, changes in water supply network pressure). This maintains constant water pressure to meet water demand even when consumption fluctuates. Variable frequency constant pressure water supply technology Variable frequency constant pressure water supply products are developing towards higher reliability, fully digital microcomputer control, and a wider variety of series. The pursuit of high intelligence, serialization, and standardization is an inevitable trend for future water supply equipment to adapt to the requirements of large-scale intelligent building development, network water supply scheduling, and overall planning in urban construction. In just a few years, speed regulation constant pressure water supply systems have undergone a gradual development process, with early single-pump speed regulation constant pressure systems gradually being replaced by multi-pump systems. Single-pump products have simple and reliable system design, but the deep speed regulation of the single-pump motor results in low operating efficiency of the pump and motor. Multi-pump products, on the other hand, offer more economical investment and higher operating efficiency, and have become the dominant product. Variable Frequency Constant Pressure Water Supply Control Method Based on the working principle of a water pump, the power consumption of the pump is proportional to the cube of its speed, i.e., N=Kn (where N is the power consumption of the pump, Kn is the pump speed, and Kn is the proportionality coefficient). While the pump is designed for power frequency operation, the flow rate is relatively low most of the time, except during peak hours. By employing variable frequency technology and microcomputer control technology, the pump speed can be adjusted according to the flow rate, ultimately achieving energy savings. Practice has shown that using variable frequency equipment can reduce the average pump speed by 20% compared to the power frequency speed, thus significantly reducing energy consumption, with energy efficiency reaching 20%–40%. Control Method with PID Loop Regulator and/or PkO In this method, the variable frequency drive provides a variable frequency power supply to the motor, enabling stepless speed regulation of the motor, thereby making the water pressure in the pipe network controllable. The sensor's task is to detect the water pressure in the pipe network; the pressure setting unit provides the system with the desired water pressure to meet the user's needs. After the pressure setting signal and pressure feedback signal are input to the programmable controller (PLC), the PLC's internal PID control program calculates and sends a frequency control signal to the frequency converter. Another method is to send the pressure setting signal and pressure feedback signal to the PID loop regulator, which then calculates and sends a frequency control signal to the frequency converter. [b][align=center]For details, please click: Using PLC and Frequency Converter to Achieve Constant Pressure Water Supply[/align][/b]