Performance Analysis of Centrifugal Pumps Subjected to Voltage Variation and Unbalance

Frequent variation of single-phase loads on power system networks results in voltage fluctuations and imbalance at consumer terminals. The application of such fluctuating voltages to operate centrifugal loads causes large variations in system performance. As a consequence, the incorporation of large safety factors have resulted in efficiency of pumping operations being less than 50% in most cases. However, small improvements in pump efficiency can lead to a significant reduction in energy consumption, and at the same time energy usage can be optimized. The operating point of a pump is obtained when the system curve intersects the pump curve. Variation in applied voltages leads to variation in the operating point, leading to inefficiency of system operation. This paper presents the impact of voltage variation and imbalance on the working performance of an induction motor-driven centrifugal pump system with an experimental study. Both overvoltage and undervoltage conditions along with phase imbalance were considered for analysis.