Experimental Transient Behaviour Characterisation of Induction Motor fed by Variable Frequency Drives for Pump Applications

The use of variable frequency drives in centrifugal pump applicationshas raised the question of how to select a drive. Clogging obstacles inwaste water applications create unknown transient loads for the pumpsystem. A sudden load increase occurrence can clog the pump if thedrive cannot supply enough current to reach the motor’s torque demand.In order to select a suitable drive, an empirical approach has been implemented,investigating three different drives. Results have shown thatselecting a drive with the highest possible overload capabilities, evenif for a short time is most suitable. Operation in vector speed controlgives the most reliable operation if an automatic parameter tuning isperformed by the drive.