Determination of Global Efficiencies of Variable Speed Pumps within Water Supply Systems

The energy transformations involved in the operation of the pumping installations are carried out by pumping aggregates consisting of an electric motor and a pump. In order to provide a full adaptation to the users’ variable demands, variable speed motor driven pumps are used on networks (such motors being equipped with frequency converters). The paper presents a method for determining the global efficiency of a frequency converter-asynchronous motor-pump group. The method has been implemented at the Chiriţa Pumping Station, main facility within the Iasi City water supply system.