With the ever-increasing complexity of interconnected power grid

the development of technology and the demand for advanced management

the understanding and application of area control error(ACE)should progress with the times. From the perspective of control performance assessment of active power balance operation for the interconnected power grid

a systematical and deep analysis has been conducted on ACE and related basic concepts. It has been found that the deviation between the frequency bias coefficient and the natural frequency response coefficient is the key factor influencing the accuracy of active power balance control. Then

it is proposed that measures to improve the relevant control performance should be provided from the aspects of planning

scheduling and dispatching. The new concepts of dynamic natural frequency response coefficient and dynamic ACE time series are presented as new ideas for the design of new evaluation standards.This work is supported by National Natural Science Foundation of China(No. 51677018)and State Grid Corporation of China.