Low Inertia Power System Planning Considering Frequency Quality Under High Penetration of Renewable Energy

With the gradual replacement of synchronous generators by renewable energy sources, the power imbalance in the system is exacerbated by the fluctuations of renewable energy output. Simultaneously, traditional frequency regulation resources will become insufficient with the reduction of online capacity of thermal units. These trends both lead to a decrease in the performance of power system frequency regulation. The planning of power system generation, particularly frequency regulation resources, will significantly influence the future quality of frequency. This paper proposes a frequency-constrained generation planning method under a high-proportion renewable energy system. The performance of power system frequency regulation is analyzed based on the simulation of the load-frequency control dynamics, where both the frequency regulation from conventional generation and renewable energy are taken into consideration. Non-linear frequency constraints are extracted from the generated data set, and then embedded into the power system planning model by utilizing a sparse weighted oblique decision tree. The case study on HRP-38 system validates the effectiveness of the method. The influence of renewable energy frequency regulation on unit commitment is also investigated.