Active Distribution Grids Providing Voltage Support: The Swiss Case

TL;DR

This paper presents a centralized optimal power flow control scheme for active distribution networks in Switzerland, enabling voltage support services to the transmission network by optimizing DER operations.

Contribution

It introduces a tractable OPF-based control method that incorporates Swiss voltage support constraints and assesses benefits under various DER inverter modes.

Findings

The control scheme effectively manages voltage support in a multi-voltage level system.

Operational modes of DER inverters significantly impact ancillary service provision.

The approach demonstrates practical potential using a combined HV-MV-LV test system.

Abstract

The increasing installation of controllable Distributed Energy Resources (DERs) in Distribution Networks (DNs) opens up new opportunities for the provision of ancillary services to the Transmission Network (TN) level. As the penetration of smart meter devices and communication infrastructure in DNs increases, they become more observable and controllable with centralized optimization-based control schemes becoming efficient and practical. In this paper, we propose a centralized tractable Optimal Power Flow (OPF)-based control scheme that optimizes the real-time operation of active DNs, while also considering the provision of voltage support as an ancillary service to the TN. We embed in the form of various constraints the current voltage support requirements of Switzerland and investigate the potential benefit of ancillary services provision assuming different operational modes of the DER inverters. We demonstrate the performance of the proposed scheme using a combined HV-MV-LV test system.