Modeling adjustable-speed drives with long feeders

This paper presents the modeling of different topologies of electric drive systems when the cable that connects the converter to the motor has a signi ficant length. The long feeder together with converter harmonics decrease t he performance of the motor. To correctly assess the voltage and the curren t throughout the drive system, frequency-dependent models for the cable and the motor should be used. A frequency-dependent cable model is necessary f or an accurate voltage evaluation while a frequency-dependent motor model r esponds for accuracy in the current. The models were validated through expe rimental results carried out on an actual oil platform and from a prototype system. The latter system was used to test the system's performance when v ery long motor leads (longer than 5 km) are involved.