Impact of large scale wind penetration on power system frequency stability

Abstract

Among the various renewable sources of energy, the wind power is by and large the fastest growing of all. Wind power contributes a large proportion of the total power generation and as per the current trend it is going to increase further. Since the wind energy conversion systems use different type of generators from the conventional generation, the effect of the large-scale wind penetration on power system need to be studied. Doubly-fed induction generators which are mostly used in wind energy conversion systems connect to the grid indirectly; their mechanical speed of rotation of rotor is decoupled from the electrical grid frequency. Thus they do not contribute to the primary frequency control. As the penetration of wind in the system increases, the inertia of the system will decrease correspondingly. Thus the rate of change of frequency (ROCOF) will increase and any system contingency may result in critical conditions like blackouts. Therefore this paper presents the complete dynamic model of wind energy conversion systems to study the effect of large-scale wind penetration on power system frequency stability.