Abstract: With the progress development of social economic and the construct scale of city continuously enlarge, increasing of population and standard of living of people continuously improved, more and more demanding to quantity, quality and stability of water supply bring forward in city. With these advantages of energy-saving, low maintenance and easy automatic control ,variable-frequency speed regulation technology has been widely used. After the introduction of the principles of variable-frequency drive technology, the thesis analyzed mechanical characteristics. According to the analysis of pump energy saving, during the pump verified velocity, the quantity of energy waste lie on the type of flow control, and combined with several regular methods comparison, the advantage of variation velocity is concluded. Has calculated that in large-scale pumping stations and power installations and major changes in the larger lift pumping station using energy-saving effect of VVVF significantly
Key words: Pump; Energy saving; Variation velocity
