Australian Research for Global Power System Transformation (Stage 3) Topic 2

The Australian power network is undergoing rapid transformation with the inclusion of increasing amounts of inverter-based resources (IBRs), particularly storage and batteries, in the interconnection queue. This may lead to retirement of conventional rotating machine power plants, sometimes before a planned retirement date. While this change in generation resource mix has been shown to deliver secure electricity supply for specific operational snapshots, the ability of the system to retain its stability, security, and reliability over extended periods of time with the occurrence of multiple events, is not known.
A lot of work was conducted in the stage 2 of this project. As a recap, stage 2 focused on determining the stability of a network with IBRs, by developing and improving analytical methods to ascertain the required operating points from IBRs in the bulk power system to operate in a stable and reliable manner.

In stage 3, the goal is to identify the impact of output current (which is related to voltage at the terminals of the device in addition to the active and reactive values). Based on the evaluated value of active and reactive power, along with the voltage from the powerflow solution, the value of output current will be ascertained. Following this, the stability of the network with different values of current limits (and associated rating of the devices) will be evaluated. This evaluation can provide insight into the required sizing of IBR devices that goes over and above the requirements for resource adequacy and flexibility reserves.