A Method for Sizing Energy Storage System to Increase Wind Penetration as Limited by Grid Frequency Deviations

Frequency deviation of power systems caused by grid-connected wind power fluctuations is one of the key factors limiting the level of wind penetration. Applying an energy storage system (ESS) to overcome the constraint of frequency deviation can increase the level of permitted wind penetration. This paper proposes a method to evaluate the wind penetration as limited by grid frequency deviation and to size the ESS to increase the permitted wind penetration to an expected level. The proposed method treats wind power fluctuations as a stochastic process rather than deterministic signal and takes the frequency response characteristics of power grid into full consideration. Application of the proposed method is based on theoretical derivations and does not require conducting dynamic simulation. It can catch the stochastic characteristic of wind power fluctuations.