The desert

gobi

and barren areas are one of the main scenarios of renewable energy development in China. To address the challenges of long transmission distance

wide collection ranges and insufficient support for renewable energy in the desert

Gobi

and barren areas

this paper proposes a hybrid AC/DC collection and DC transmission system

which can realize the hybrid integration of multiple renewable energy bases with different locations. Firstly

the topology of the hybrid AC/DC collection and DC transmission system is introduced. Then

the operating mode diagrams are analyzed

and the coordinated control strategy is designed accordingly. Subsequently

the optimal design strategy for the system parameters based on the converter capability limit is presented. Based on the design scheme

the steady-state and transient-state operating characteristics are analyzed. Then

the economic and technical aspect of the proposed topology is investigated. Finally

this paper develops a simulation model of the hybrid AC/DC collection and DC transmission system in PSCAD/EMTDC to verify the applicability and feasibility of the proposed topology and control strategies under start-up conditions

power fluctuations and DC fault. The research results show that the system can be an alternative for large-scale renewable energy transmission in the desert

Gobi

and barren areas.