Frequency Characteristic Analysis of Power System Considering Deep Peak Load Regulation and Renewable Energy Injection

Traditional thermal power units are gradually being replaced by renewable energy such as wind power and photovoltaics, resulting in a decrease in system inertia and deterioration of frequency stability. Therefore, the thermal power units have to operate in a deep peak load regulation state to cope with the peak-valley difference of the system and improve the frequency characteristics of the system. This paper studies the frequency characteristics of low inertia power system under deep peak load regulation. First, based on the system frequency response model, a frequency analysis model considering the renewable energy penetration rate is proposed. Then, the frequency characteristics with the deep peak load regulation are analyzed. Finally, some simulations are carried out on a four-generator two-zone system containing wind farm to simulate the system frequency response after a sudden disturbance with different penetration rate and deep peak load regulation depth. The case studies show the correctness of the frequency characteristic analysis.