Effect of Voltage Fluctuations on Induction Motor Currents

One of the types of power quality disturbances met in a power system is voltage fluctuations. Cyclic voltage fluctuations are interconnected with the presence of subharmonics and interharmonics – that is components of frequency less than the fundamental frequency or not being its integer multiple. Voltage fluctuations can be considered as practical examples of the simultaneous presence of subharmonics and interharmonics of various frequencies. This study deals with the preliminary investigations on an induction motor under voltage fluctuations of frequency greater than the supply voltage frequency. The results of the empirical investigations on currents under rectangular modulation of voltage amplitude are presented for a four-pole cage induction motor of a rated power of 4 kW.