Multi‐stage coordination optimisation control in hybrid AC/DC distribution network with high‐penetration renewables based on SOP and VSC

Power electronic devices such as soft open point (SOP) and voltage source converter (VSC) begin to be applied to distribution networks, which are developed into hybrid AC/DC distribution networks. Both power electronic equipment and conventional control devices, such as tie switches, coexist in a hybrid AC/DC distribution network, and the coordination optimisation of these control devices can eliminate the risks caused by high‐penetration renewable energy generation (REG) integration. Here, the structure of the hybrid AC/DC distribution networks with SOP and VSC is analysed. A multi‐stage coordination control method is proposed, including day‐ahead stage, inner‐day stage, and real‐time stage. In the day‐ahead stage, a sequential coordination optimisation model considering network reconfiguration by switches is established; in the inner‐day stage, a loop‐locked rolling optimisation control model based on model predictive control is built, to reduce the influence of the REG randomness output; in the real‐time stage, voltage deviations are minimised in risk scenarios by regulating powers of SOP and VSC. Mixed‐integer second‐order cone programming algorithm is adopted to realise the coordination optimisation of SOP, VSC, and tie switch. The results show that the proposed method can increase REG penetrations and improve voltage quality and economic benefit of the hybrid AC/DC distribution network.