Regional Voltage Stability Studies

The regional voltage stability studies are conducted for the Upper North Island (UNI) and Upper South Island (USI) regions.

These studies are carried out twice yearly for the summer and winter peak loads, to assess any voltage stability issues that may arise due to a low generation scenario.   The analysis of these studies are now included in the Upper North and Upper South Island sections of Part D of the System Security Forecast.

Scheduling and Dispatch

Backup Procedure if primary dispatch system fails

Asset Owners are required under Part 8, Schedule 8.3 Technical Code C (4) to have a primary and backup means of voice communication between the control room of the asset owner and the system operator.

If normal dispatch systems fail, the system operator will utilise the primary or secondary voice communication means to dispatch generation instructions to asset owners.

Remedial Action Schemes (RAS)

What is RAS

RAS is an application in the system operator’s advanced energy management suite of applications that is used to provide improved management of contingencies and the modelling of the effects of Special Protection Schemes (SPS). This enables us to provide a more accurate set of remedial actions to improve Grid security.

An SPS is an automatic protection scheme installed in at a substation, the purpose of which is to take action (post event) to switch assets out of service or to reduce load or run back generation, to correct or prevent an overload.