On BESS Allocation in AC/DC Networks Using a Sensitivities-Based Loss Model Combined With Injection Shift Factors

The operation of AC/DC networks formed by voltage source converters (VSC) is difficult to optimize. In particular, the minimization of transmission losses is a challenging task to address because several VSC-coupled AC grids interact simultaneously to supply the load. In this context, this article presents a practical approach for power loss minimization in hybrid networks by allocating battery energy storage systems (BESS). The crux of this method is a sensitivities-based loss model combined with power injection shift factors. One that suitably exploits the topological structure and fundamental parameters of the hybrid network. The most suitable nodes for the BESS connection can be straightforwardly identified by using this method, while reducing the power losses and improving the system operating efficiency. Multi-terminal AC/DC networks of arbitrary topology can be studied with this new approach, considering converters with grid-following, grid-forming, fixed-power control strategies, and converters interfacing systems with no local generation or with renewable plants only. The section of case studies includes two multi-period power system analyses. One to confirm the effectiveness of the method and another to showcase its practicality, using four-terminal and six-terminal VSC-based AC/DC networks with complex patterns of demand, wind speed and solar irradiance of the renewable sources.