Template: AEMO static studies
Version: 1
NEW!Last updated: 28 Apr 2025
Country:
AU
Software required:
Source: AEMC | National Electricity Rules | Version 222 | 19 December 2024
How to download: Add a new Flow in gridmo and select this template from the list.
- Add this template to your project.
- Configure your PSS®E Static OPDMS snapshot case file (e.g. integrate committed generators). For assistance in completing this process, see Example: How to merge multiple PSS®E models into a single network model.
- Complete the Actions outlined in the template.
Background
During the generation interconnection process, it is important to understand the impact of the proposed generating system on static study phenomena (e.g. bus voltages and thermal line loading) during both normal operating conditions and contingencies. Static studies are fundamental to the generation interconnection process and should be completed prior to any dynamic studies. Static studies are typically used for the following:
| Use | Description | Project stage |
|---|---|---|
| Capacity assessments | Static studies are useful to quickly understand the available capacity in a particular part of the network and explore help estimate potential generating system sizing. Typically these studies primarily consider line and transformer thermal loading during normal network operating conditions (i.e. 'N' condition during summer/winter/autumn/spring low/high demand). | Preliminary enquiry stage |
| Network impact studies | Static studies are useful to investigate the network impact of the proposed generating system, once an approximate size has been chosen. These studies involve a detailed investigation into bus voltage change/limit violations, transformer tap usage, connection point regulation and initial control strategy (e.g. voltage droop control mode v.s. PF control mode), transformer thermal loading and line thermal loading under multiple contingencies. Mitigation strategies (e.g. run-back schemes, line reconductoring, a new transformer) must be proposed to solve any identified issues (e.g. thermal line loading violations under a contingency). | Detailed enquiry stage and Connection application stage (S5.2.5.12) |
In the future, we may add a part of the template which has static studies for a stage between the high-level capacity assessments and the detailed network impact studies.
Configuration
Capacity assessment
This is useful in the early stages of project development, where you want to understand the available capacity in a particular part of the network and explore help estimate potential generating system sizing. You may want answers to high-level questions such as:
- Could this area of the network accommodate a 100MW or 1GW generating system?
- At what generating system size will there likely be local network constraints?
Coming soon...
We propose to add a part of the template which can add generators into a particular part of the network and output N condition branch loading. It will then loop through a range of proposed generating system sizes.
Network impact studies
The network impact studies explore the several network phenomena across a variety of contingencies. The studies are completed for the existing system and with the proposed generating system.
- Bus voltages - Locked taps solution: Bus voltages must be maintained within a specified range following any credible contingency. By applying a contingency and then solving the network with locked taps, this investigates the ability of the network to maintain voltages within the first ≈30 seconds after the contingency which is the time prior to any mechanical on-load tap changer (OLTC) effects.
- Tap positions - Tapping solution: Bus voltages must be maintained within a specified range following any credible contingency. A critical part of this voltage control is achieved by using transformers with on-load tap changer (OLTC). By applying a contingency and then solving the network with tapping, we can see if transformers are at their tap position limits and the network is therefore at risk of losing its ability to regulate voltage further.
- Branch loading - Tapping solution: Long-term thermal loading of transformers and lines must be maintained within their asset rating limits. By applying a contingency and then solving the network with tapping, we can see if transformers and lines are at risk of being thermally overloaded.
- Connection point regulation - Tapping solution: During the studies, it is important to verify that the proposed generating system is regulating active power and reactive power at its connection point in accordance with the agreed control strategies.
We assume that your generating system and other nearby generating system may regulate voltage during the locked tap solution (e.g. a CONTROL Command for voltage droop control mode). This is consistent with all other generators in the network in direct voltage control. This assumes that the generating system reactive power system control mode has a settling time to the disturbance of much less than the time for OLTC and other similar network elements to operate.
- For contingencies which involve reducing the size of the generating system (e.g. 50% trip of proposed generating system), the generating system control after the contingency may be different. Many PPC active power and reactive power control systems will scale their settings based on the number of available inverters (e.g. a droop curve percentage may remain as 4%, but the Q base may scale down 50% if 50% of inverters are unavailable).
- Different NSPs may have different requirements or special formatting for detailed enquiry and S5.2.5.12 submissions. Please refer to your steady state data pack for project-specific requirements.
Assumptions
- Some GPS tests require a PSS®E model of the NEM (colloquially known as an 'OPDMS snapshot' in the industry). We do not provide these snapshots. You will have to provide your own pre-tuned dynamic base cases for these tests.
Sources
Revision history
Version 1 | 28 April 2025
- First release.