Bi-level optimisation dispatch method for photovoltaic hosting capacity enhancement of distribution buses

Distributed photovoltaic (PV) systems are being gradually integrated into distribution systems with the advantage of economy, environmental protection, and flexibility. Hosting capacity (HC) of a distribution system limited the integration of the PVs. To identify the economic efficiency of HC, two boundaries of HC for distribution buses are proposed considering the technology and economy. Then, new evaluation metrics that can identify the HC region for the PV buses are presented. A bi-level optimisation dispatch method based on iterative particle swarm optimisation for PVHC enhancement is proposed considering the benefits of both distribution network operators and PV owners. At the upper level, a linear power flow-based model is used to determine the economic PVHC and technological PVHC. At the lower level, the objective function of the maximisation of benefits for PV owners is presented. The punishment coefficient of the PVHC region is incorporated into the optimisation dispatch model. Finally, the demonstration is performed on modified PG&E 69-bus and IEEE 123-bus distribution systems. The simulation results show that the proposed bi-level optimisation dispatch method can effectively increase the PVHC margin of distribution buses, and the presented evaluation metrics are of great practical significance in a deregulated environment.