Minimum Primary Reserve Calculation for Renewable Energy Generation with Additional Frequency Droop Control Based on Dynamic Frequency Stability Constraints

With the increasing penetration of renewable energy sources (RES), the frequency security issue in power systems has become more prominent. Despite many scholars have extensively researched the techniques and operated mechanisms for frequency support of renewable energy (RE) generation from various aspects, system dispatchers still hope to minimize the reserve requirement for new energy due to its high cost. In this context, this paper proposes a minimum reserve calculation method for RE generation considering maximum frequency deviation constraints, in order to ensure frequency stability during primary frequency regulation (PFR) in a system with high load and low reserve, while addressing the implicit relationship between the system's frequency response and the generator output capability. Firstly, a frequency response model of an aggregated system containing RE generation is established with consideration of limiting links. Then, under typical system parameters and operating conditions, the frequency dynamic response processes of traditional generation and RE generation are derived. The approximate implicit relationship between the initial power output and the maximum frequency deviation is estimated through local linearization of the frequency dynamic process. Based on this, an algorithm is proposed to determine the critical reserve requirement for RE generation corresponding to the maximum frequency deviation. The effectiveness of the proposed method is verified through case studies on IEEE 9-bus and 39-bus modified test system.