A Robust Optimization Approach to Enhance Frequency Stability by Renewable Energy Sources

With increasing penetration of renewable energy sources (RESs) and the consequent displacement of synchronous generators (SGs), the frequency stability of power systems has been challenged since RESs generally do not provide inertial response (IR), primary frequency response (PFR), and are non-dispatch able. This paper focuses on enhancing frequency stability by incorporating RESs into the active power and frequency control framework in AC systems. First, we modify uncertain RES generation into dispatchable and stochastic portions. Second, the constraints corresponding to the required system inertia and droop parameters synthesized by the modified RESs and SGs are derived. Third, a security-constrained economic dispatch model is proposed containing the frequency regulation and reserve provision constraints. The proposed model is tested by the modified 39-bus system. The results show that frequency regulation performance is promoted.