In order to improve the economy of frequency regulation of the interconnected power system on the premise of ensuring the small signal stability

we put forward an optimal coordination frequency control strategy of automatic generation control（AGC） in multi-area based on bi-level model control. Firstly

based on the whole power grid

taking eliminating the system frequency deviation as the primary purpose

we establish an optimization model for coordination frequency control of multi-area AGC in the upper layer

and adopt the nonlinear programming algorithm to solve the optimization model. Then

considering the dynamic stability of power system

we establish an optimization allocation model of AGC command with small signal stability constraints in the lower layer. Moreover

to solve the established optimization model

we propose an improved strategy based on a nonlinear programming algorithm. Finally

based on the improved IEEE-30 bus distribution network

the validity of control strategy is verified. The results show that the proposed control strategy improves the economy of interconnected system frequency regulating and ensures that dynamic performance of system meets the demands of analysis on small signal stability. The improved algorithm strategy improves the convergence property

and improves the computation speed when ensuring the optimization accuracy.