Diagnostics of large drives for pumping systems.

Abstract

After the fssembly of controled electric drive for pumping system computerised measrement station certified that mechanical resonance appeared around 10 kHz current harmonics providing pull-up torque together with the self-frequency of the motor wthich was also 10 kHz.The switching frequency of the inverter had an increase up to 12 kHz and resonances were eliminated.The lesson is that both the switching and the self-frequency must be taken intj consideration to reduce time of start motor.