Based on analyzing the drives

state-of-the-art and proposed development of applied technology of coordinated control among multiple control areas

by taking the dynamic area control error(ACE)of East China power grid as an example

potential solutions to some problems suggested in the previous paper are reviewed. First

the basic theory and application of dynamic ACE are introduced

and the problems of dynamic ACE are discussed. Then

a calculation model for available transfer capacity of tie-lines used for estimating reserve capacity deliverable is developed

while an improved algorithm for reserve sharing is proposed to activate automatic generation control(AGC)and contingency reserve among multiple control areas in the same direction. Furthermore

corrections considering the available transfer capacity of tie-lines between areas are proposed. The joint application of the corrected ACE method and current security constrained dispatch system provides a possible approach to hierarchical congestion management. This work is supported by State Grid Corporation of China.