A highly efficient physical platform is provided by inter-regional high voltage direct current(HVDC)tie-line for large-range cross-region clean energy accommodation and resources allocation. The cross-regional coordinative optimization potential of power resources can be tapped and the accommodation capability of clean energy improved if complementary characteristics of power supply structure and system load of each region are well utilized. To this end

a generation and transmission scheduling mode of inter-regional power grid via HVDC tie-line is proposed based on the two-level “state-province” system operation pattern. In this mode

the transmission power of HVDC tie-line is viewed as cross-regional coordinative variable while generator scheduling is optimized inside each region. A mathematical model of generation and transmission scheduling mode of inter-regional power grid via HVDC tie-line is developed with various practical operation constraints taken into account

including the HVDC flexible adjustment constraints

tie-line daily transaction energy limit and tie-line power profile stair-like requirement. An inter-regional marginal-units-identification method guided by HVDC tie-line power is addressed to enhance the solving efficiency of the proposed largescale mixed integer programming model. A case study is conducted using the real world load profile of a provincial power grid to validate the effectiveness of the proposed mode

model and method. This work is supported by National Key Technologies R&D Program of China(No. 2013BAA01B02)and State Grid Corporation of China(5229NX15002B).