Abstract : This paper introduces two schemes for variable frequency speed control of two water pumps in a constant pressure water supply system, using a dual-channel inverter circuit with one-to-two control and DSP control. The two schemes are analyzed and compared, with the DSP-controlled dual-channel inverter circuit scheme showing better performance. Keywords : Constant pressure water supply; Variable frequency speed control; DSP control; Inverter 1 Introduction to Constant Pressure Water Supply Speed ​​Control System Variable frequency drive (VFD) constant pressure water supply devices are technologically mature and have received positive market feedback. From energy-saving operation to system stability and reliability, they have gained social recognition. This system has been continuously updated and developed along with the advancements in controller and VFD technology. Regarding controllers, development has progressed from relay logic, microcontrollers, and PLCs to dedicated controllers. Regarding VFD speed control, its development has gone through multi-segment speed control, analog input control, and dedicated controller control. The constant pressure water supply speed control system automatically adjusts the system's operating parameters based on changes in water consumption, maintaining constant water pressure to meet water requirements. It is a modern, advanced, and energy-efficient water supply system. In just a few years, the speed-regulating constant pressure water supply system has undergone a gradual development process, with the early single-pump speed-regulating constant pressure system gradually being replaced by multi-pump systems. Although single-pump products are simple and reliable in system design, the deep speed regulation of the single-pump motor results in low operating efficiency of the pump and motor, while multi-pump products are more cost-effective and have higher operating efficiency. Variable frequency speed regulation is the most advanced AC speed regulation method today. With the gradual decline in international inverter prices, the application of variable frequency speed regulation technology is becoming more and more widespread. This article mainly proposes two variable frequency speed regulation schemes for dual-pump constant pressure water supply systems and analyzes and compares them. [b]2 Variable Frequency Speed ​​Regulation Control Strategy 2.1 One-to-Two Control[/b] In this system, a scheme of switching and controlling two electric pumps using one inverter is adopted. The two electric pumps are connected to the grid for water supply. When the water consumption is low, the inverter supplies power to the electric pumps and adjusts the frequency and delivers water according to the water consumption. When the water consumption increases and the inverter pump has reached its rated speed, the first electric pump is switched to the mains frequency. The inverter supplies power to the second electric pump. Thus... Depending on water consumption, one fixed-frequency pump and one variable-frequency pump are connected to the network for water supply. [b][align=center]For details, please click: Research on Variable Frequency Speed ​​Control of Dual-Pump Constant Pressure Water Supply[/align][/b]