Distributionally Robust Joint Chance-Constrained Coordinated Dispatch for VSC-MTDC-Based Integrated Transmission-Distribution Systems

The coordination and interconnections of power networks are crucial for power systems dispatch with high-proportion variable renewable energy (VRE). Recent studies have separately explored the transmission-distribution system integration and the interconnections of transmission (distribution) systems via voltage source converter multi-terminal direct current (VSC-MTDC) grids. However, few researches concentrate on the combination of these two technologies, which contains admirable potential operation flexibility to absorb massive VREs. This paper proposes a dispatch model for VSC-MTDC-based integrated transmission-distribution systems based on the distributionally robust joint chance-constrained programming (DRJCCP) framework. At first, two approximation approaches of network losses according to different reactance-resistance ratios are proposed for transmission and distribution grids, respectively. Then, the extended affine strategy is embedded in the DRJCCP framework to map the relation between VRE uncertainties and dispatch decisions. Finally, based on the hierarchy, a decentralised optimisation algorithm based on analytical target cascading is utilised, which divides the whole dispatch problem into the bi-level problem of transmission and distribution grids. Numerical tests on different scale systems demonstrate that the proposed method balances decision-making realism and robustness, highlighting the strategic and operational aspects of coordinated dispatch across different hierarchies and regions.