Overview of Limiting Factors and Prospects for Systematic Evaluation of the External Transmission Capacity of Renewable Energy Base in Desert， Gobi and Barren Areas

[Objective] With the construction of China’s new power system， renewable energy bases in desert， gobi and barren areas are gradually becoming crucial power suppliers. Based on the planned capacity of these bases， the actual power delivered to receiving-end grids is influenced by various external factors， involving different stakeholders across multiple stages. Therefore， for the complex system comprising multi-base sources， multi-channel transmission， and multi-receiving ends， evaluating the transmission capacity of any single base requires a comprehensive consideration of multiple factors. [Methods] This study analyzes the entire process of power transmission from the base power sources to the receiving-end grids via transmission channels. By reviewing existing research in each domain， various factors affecting the base’s power transmission capability are elaborated in detail. [Results] The transmission process can be divided into three stages： the base power source， the transmission channel， and the receiving-end grid. In the power source stage， fluctuations in renewable energy and grid-following and grid-forming technologies affect the active power output. In the transmission stage， control strategies of either conventional direct current transmission technology or flexible direct current transmission technology， along with the strength of both sending-end and receiving-end grids， determine the channel's maximum transmission capacity. In the receiving-end stage， single direct current feed-in， multi-direct current technology combination schemes， and multi-direct current coupling affect the receiving-end grid’s power acceptance capability. A comprehensive assessment of the base’s transmission capacity must integrate the aforementioned factors. [Conclusions] The proposed systematic evaluation method can promote collaborative efforts among stakeholders across different stages. By comprehensively considering the constraints of base capacity planning and transmission-affecting factors， this method provides technical insights and references for accurately assessing the transmission capability of complex systems involving renewable energy bases in desert， gobi and barren areas.