Incorporating inverters with Volt-var/Watt control in distribution network constrained optimisation

The rapid growth of distributed energy resources (DERs) connected to distribution networks via power electronic inverters demands detailed network modeling to address operational and planning challenges. Inverter designs, including single, three-and four-leg topologies, along with Volt-var/Watt and grid-forming/following modes, limit operational flexibility and introduce nonlinearities in response to voltage and current changes. This paper examines how nonlinear network optimisation can improve upon simulation methods to support power quality services like phase unbalance compensation and voltage regulation using smart inverters and active filters. A conceptual dynamic operating envelope case study employing a four-wire optimal power flow model demonstrates how network-constrained optimisation and advanced inverter modeling enhance DER integration, delivering significant benefits to industry and end-users while enabling a more resilient and adaptive power system.