Analysis Method for Frequency Spatial-Temporal Distribution Characteristics of High-proportion Photovoltaic System Based on Power Measurement

Abstract

At present, the global response analysis of power system frequency usually adopts the common mode frequency of the system. However, as the proportion of renewable energy in the power system continues to increase, the characteristics of system inertia reduction and uneven distribution of frequency regulation resources are becoming increasingly apparent. The frequency deviation index between nodes can reflect the distribution differences of system frequency in time and space. To obtain the accurate measurement values of frequency deviation between nodes, a power measurement method is proposed. With this method, the frequency variation of the system can be obtained by measuring the power fluctuation in the condition that the internal structure and control parameters of the unit are unknown, and the frequency spatial-temporal distribution characteristics of the system can be analyzed. Firstly, the frequency spatial-temporal distribution characteristics and influencing factors of the system with high proportion of photovoltaics after disturbance are analyzed using the frequency deviation between nodes obtained through simulation models. Secondly, the inter-node frequency deviation obtained by power measurement method is compared with the inter-node frequency deviation measured by phase-locked loop and synchrophasor measurement unit to verify its accuracy. Finally, the frequency deviation between nodes obtained by the proposed method can effectively reflect the spatial-temporal distribution characteristics of the system frequency through simulation and experimental tests.