Impact of high penetration of renewables on power system frequency response: A review and verification

The characteristics of modern power systems are significantly changing due to the high penetration of renewable energy sources (RESs). While this energy transition offers numerous economic and environmental benefits, it may cause serious frequency stability problems if proper actions are not taken. In order to address these issues, all key factors, such as inertia, ramp rate of frequency response, primary frequency reserve, etc., must be systematically analyzed with their accurate cause and effect on frequency stability. This paper first defines the relationships between the primary and secondary factors and frequency stability indices. Then, the paper clarifies seven representative cases for possible frequency stability problems in modern power systems, considering the penetration levels and variations of RESs, with a comprehensive assessment. Thereafter, the paper provides an overview of solutions for enhancing frequency stability and discusses potential solutions for each representative case. The effectiveness of proposed analysis is verified by case studies on the IEEE 39-bus test system and practical Jeju Island power system. The results show that this approach can provide valuable information for making the proper decisions and measures for power systems with a high penetration of RESs.