The effects of harmonics & resonance on a weak network with DFIG based wind generation

Abstract

Large industrial networks connected to weak utility based networks can make use of local generation in order to improve reliability or to make use of excess heat for other purposes (gas turbines, diesel sets etc.). Utilisation of 2nd order damped filters to limit harmonics are common place when large power electronic based drives are used. Given the need to make use of some degree of renewable energy systems is has become necessary to obtain an understanding of how the network stability will be affected when such technologies are considered. The application of a DFIG based wind generation system interconnected to a weak industrial network that makes use of 2nd order damped filters is investigated in order to determine how and if resonance can take place. The results of such a review have shown that with a changing network (SCC, voltage connection and load) the addition of wind generation can assist in limiting potential resonance impedance issues and offer higher stability to the distribution system. This can be particularly effective with weak networks that experience significant changes to SCC at the point of common coupling with minor network changes as has been the case with this review.