With the operation of Chongqing-Hubei back-to-back flexible DC project of China

the scale of Southwest Power Grid with multi-DC weak sending and high proportion of hydropower is significantly reduced. Considering the test operation of the Southwest Power Grid in asynchronous mode

and the existing problems in automatic generation control(AGC)algorithms and modelling methods are analyzed. Based on the proportional-derivative control law

a computational method of area regulation requirement is proposed to increase the stability of the system by reducing errors in advance. Based on the relationship between low-pass filter process and control quality

the setting of dynamic filtering factors for different working conditions is developed to balance the dynamic response performance and frequent adjustment of units output. The optimization scheme for establishing the control areas and relevant control strategies is proposed in order to meet the demands for the efficiency and safety in actual operation. Verification simulations are carried out and AGC full dynamic simulation results prove the effectiveness of the proposed optimization methods based on the platform of the PSD-FDS.