An EID Load Frequency Control Method for Two-Area Interconnected Power System with Photovoltaic Generation

Two-area interconnected power system with photovoltaic generation (PVG) has load disturbances and power fluctuations of PVG affected by weather changes. These disturbances can cause system power imbalance and frequency fluctuations. Effective frequency control method is very necessary. This paper proposes an equivalent input disturbance (EID) load frequency control method for two-area interconnected power systems with PVG. The EID method controls the output power of traditional thermal generation subsystem by using the estimated equivalent external disturbance information to form new input signals. In this way, the power fluctuation of PVG and load disturbance are compensated, and the frequency stability is maintained. Compared with the traditional PI control method and the PI control method based on the firefly algorithm (FA-PI), the results show that the frequency fluctuation range of the proposed EID method is about 90% lower than that of the PI method and FA-PI method. The EID method can more effectively compensate for the effects of external disturbances, suppress frequency fluctuations and stabilize the system.