A Novel Approach on UFLS of Power System with Wind Power and Thermostatically Controlled Resources Participating in Frequency Regulation
Lingyu Sun *
School of Electric Power Engineering, Nanjing Institute of Technology, Nanjing, China.
Jia Ning
School of Electric Power Engineering, Nanjing Institute of Technology, Nanjing, China.
*Author to whom correspondence should be addressed.
Abstract
Against the backdrop of continuously increasing renewable energy penetration, the large-scale integration of wind power has significantly altered the output characteristics of generation units. The growing volatility of wind power output exacerbates the complexity of frequency regulation, potentially rendering traditional under frequency load shedding (UFLS) strategies inadequate. Investigating methods that leverage the frequency regulation capabilities of doubly-fed induction generators (DFIGs) and coordinated demand-side load clusters to participate in UFLS holds significant research value for enhancing power system frequency stability, reducing load curtailment, and improving power supply reliability. Therefore, this paper proposes an optimized UFLS strategy considering large-scale wind power integration. The frequency response models of wind turbines and thermostatically controlled loads (TCLs) in grid frequency regulation are analyzed, and the configuration principles for implementing UFLS in power systems are elaborated. A simulation model incorporating both wind turbines and TCLs in frequency regulation is developed, and UFLS simulations are conducted based on the operational conditions of a regional power grid. The results demonstrate that the participation of wind power and TCLs in frequency regulation not only ensures grid security but also significantly reduces load curtailment.
Keywords: Doubly-fed induction generators, thermostatically controlled loads, under frequency load shedding