Abstract : This paper introduces the structure and working principle of a constant pressure water supply system for a residential community based on a frequency converter. The system adopts frequency conversion speed regulation to automatically adjust the speed of the water pump motor, maintain a constant water supply pressure, and activate a small flow pump during off-peak water usage to reduce power consumption. The system has advantages such as energy saving, reliable operation, and high degree of automation, thus improving the quality of water supply. Keywords : Constant pressure water supply system, frequency converter 1 Introduction The daily water supply of a residential community varies over time, with significant differences between seasons and day and night. Therefore, the imbalance between water consumption and supply is mainly reflected in water pressure: low water pressure when water consumption is high and supply is low, and high water pressure when water consumption is low and supply is high. Traditional methods use water tanks and water towers or gas cylinders for pressurization, which have obvious shortcomings in terms of water supply quality, daily maintenance and management, and handling of unexpected fires. Due to the development of power electronics technology, frequency conversion speed regulation technology has been widely used in water supply systems. [b]2 System Composition and Working Principle 2.1 System Composition[/b] The basic control strategy of the constant pressure water supply control system is to use a motor speed regulating device and a programmable logic controller (PLC) to optimize the speed control of the pump group and automatically adjust the number of pumps in operation to complete the closed-loop control of the water supply pressure. This achieves stable water supply pressure and energy saving when the pipeline flow changes. [b][align=center]For details, please click: Variable Frequency Drive-Based Community Constant Pressure Water Supply System[/align][/b]