The Influence of High-penetration Pumped Storage Units on the Transient Angle Stability

Connecting high-penetration pumped storage (PS) units to the grid may aggravate the transient angle stability (TAS) of the power system in some special situations. However, there still lacks the proper method to analyze the influence of the high penetration of PS units on the TAS quantitatively. Therefore, a methodology that is suitable for assessing the transient angle stability margin (TASM) of the system with high-penetration PS units connected is proposed. For the first, the dynamic characteristics of the PS unit are analyzed, and the equivalent circuit (EC) is obtained. Then, the EC of the whole system is constructed by combining the obtained EC of the PS units with the EC of the other components in the system. Further, by analyzing the changes in the electromagnetic power (EP) before and after the fault occurs, calculate the acceleration area (ACA) and the deceleration area (DCA) based on the equal area criterion (EAC), and then the TASM is obtained to reflect the TAS of the system quantitatively. Finally, the effectiveness of the proposed method is verified via an example from the actual regional power system in China.