Power Saving of Multi Pump-Motor Systems Using Variable Speed Drives

A direct-connected multi pump-motor system suffers from energy loss during the process of varying water head and flow at fixed operating point. In This paper, two variable-speed drive strategies are adopted for driving a multi pump system and selecting number of the operated pumps for achieving the required head and flow with energy saving. A comparison between multi-pump single drive (MPSD) system and multi pump multi drive (MPMD) is presented. The comparison of two methods are verified by simulation results and the dynamic performance of the system is studied. The overall system efficiency is analysis for two case studies. From the results, the system efficiency could be improved and then energy could be saved by using MPMD system.