Multinational power grid interconnections play a critical part in supporting the vision of global energy internet. During the early stages of the Global Energy Internet

the value proposition of multinational interconnections should be carefully investigated in order to stimulate the activities for associated countries in such potential interconnections. This paper proposes a new e conomic benefit evaluation model which is quantified by using a chronological production cost simulation approach. The economic benefit model comprehensively considered investment costs and the benefits of the decrease of load payments and the increase of net generation revenue due to a transmission project interconnected with different countries. This economic benefit model can assist to quantitatively determine the optimal transmission capacity for multinational interconnections to achieve maximum economic benefits as a whole. In the case study

the economic benefit of an interconnected system of western China and the Gulf States is assessed by using the method proposed in this paper. And the optimal interconnection capacity with maximum benefit is achieved. The case study shows that the proposed method can be used for economic benefit assessment and is of great significance to the multinational and inter-continental transmission interconnections.