Transmission Expansion Planning Coordinated with Distribution Networks Considering High Renewable Energy Penetration

With the penetration of renewable energy (RE) into power system, the coupling degree of transmission and distribution network is increasing, and the independent transmission network planning method is no longer applicable consequentially. It is necessary to consider the transmission network planning coordinated with the distribution networks (TEPCDN). However, there is a lack of standard test system for coordination planning research. This paper constructs a transmission expansion planning test system coordinated with distribution networks named HRPTD-20 system. “HRP” stands for high renewable penetration and the installed proportion of RE is more than 50%. The test system includes 3 voltage levels, 3 traditional and 3 typical future distribution network structures, with distinct spatial and temporal characteristics of source-grid-load. Then, a multi-scenario distributed TEPCDN model is proposed, aiming at minimizing the sum of investment cost of transmission network and operation cost of transmission and distribution networks, taking active power and voltage as interactive variables, and is solved by the optimization algorithm based on analytical target cascading (ATC). Finally, benchmark planning scheme for the HRPTD-20 system is provided. Compared with independent transmission network planning, the TEPCDN helps to improve the economic benefits and RE consumption ratio.