Practical Methods for Online Monitoring of Harmonic Resonances in DFIG-Based Wind Parks

Harmonic resonances in wind parks have become an important power quality concern for utilities. Even though they can be analyzed through detailed electromagnetic transient (EMT) simulations or frequency-domain simulations, these studies can be time consuming. In response, the authors have developed two graphical, easy-to-use approaches for a quick initial screening of the risk of voltage THD violation or component overload inside the wind park due to harmonic resonances. Both approaches are suitable for real time (online) application if harmonic voltage and current measurements are available at the point of common coupling (PCC) between the wind park and the grid. This paper describes and discusses both methods, which were recently published by the authors on the IEEE Transactions on Power Delivery journal [1], [2]. A discussion on techniques to process measurement data so that the proposed methods can be applied online is also provided.