Sequence component models to calculate fault current contributions from wind generators

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

SEQUENCE COMPONENT MODELS TO CALCULATE FAULT CURRENT CONTRIBUTIONS FROM WIND GENERATORS ABSTRACT The objective of this research is to develop new dynamic sequence component models for doubly-fed induction wind generators in order to calculate the positive, negative and zero sequence currents from such large wind plants to a grid fault. The approach is to simulate these faults in the time domain using accurate machine and power electronic models, and develop their sequence component models in the frequency domain. Protection relays measure the sequence component currents, but until now utility protection engineers have not been able to accurately calculate relay settings at the nodes where wind plants are connected to the utility network. When the wind generator circuit topology changes within the milli-second range, it is necessary to have time varying or dynamic sequence component models based and adapting this information to relay settings will be a fundamentally new area to power engineering. This method could also be applied to other three phase systems and machines, and even lead to completely new relay designs. Reliable and secure electricity is the backbone of society. Incorrect relay settings based on incorrect sequence modeling, can lead to failure to interrupt faults, or to nuisance tripping of the power. Failure to interrupt could in turn lead to personal injury, or severe damage to equipment. The results will be disseminated through publications and various IEEE Working Groups, and included in a graduate level course on electrical machines taught by Dr. Harley. Two undergraduate minority students from the Opportunity Scholars Program (OSP) at Georgia Tech will be involved.