Connection Studies
Once you have identified a vendor for your generating asset, you will need to conduct System Operator Connection Studies. These studies will need to be conducted using a vendor RMS model on the powerfactory EMI case and/or a vendor EMT model on one of the EMT cases provided below. You need to perform connection studies to simulate the performance of your asset when connecting to the wider power system. The System Operator needs to review these so that we can:
- assess the new generating station’s ability to help the system operator plan and meet the Principal Performance Obligations
- anticipate any potential operational issues that can constrain the operation of the new generating station, such as thermal constraints, transient or voltage stability issues
- assess compliance to the Code, including requirements such as reactive power, frequency control, and fault ride through standards, to ensure the new generating station does not reduce the supply quality and reliability
- minimise risk during commissioning and testing
- assess the impact of the new generation connection on power system stability and supply security
- ensure power system operation and other grid connection parties are not affected by the new generation connection
Refer to GL-EA-953 Connection Study Requirements for Connecting a New Generating Station for a breakdown of all the studies that we require you to complete. If you are undergoing the commissioning generation process, we expect you to scope and plan these early on. See our GL-EA-404 Generation Commissioning Process document for the specific timings.
To complete your connection studies, you will need to submit study casefiles with use a unvalidated vendor model of your asset. For more information on these, see the section at the bottom of this page.
Note for Fault Ride Through (FRT) Studies
Fault Ride Through studies are a Code requirement and must to be demonstrated using power system analysis i.e. RMS studies and/or EMT studies.
To perform an RMS study, use your vendor RMS generator model and the PowerFactory EMI case, which you can access at the Electricity Authority’s webpage at Electricity Authority - EMI (market statistics and tools), along with supporting documentation.
To perform an EMT study, use your vendor EMT model and the EMT network models provided below. The EMT network models are divided into Grid Zones to improve computing efficiencies. To support you with you EMT study, we recommend you refer to the relevant user manual and PSCAD EMT model files below.
| Model for use in Grid Zone(s) | Model | Model Version | User Manual |
|---|---|---|---|
| 1, 2, 3 | Northland, Auckland and Hamilton Generic Model | 2.0 | Northland, Auckland and Hamilton EMT model documentation |
| 4 | Edgecumbe Generic Model | 2.0 | Edgecumbe EMT model documentation |
| 5 | Hawkes Bay Generic Model | 1.0 | Hawkes Bay Generic model documentation |
| 6, 7, 8 | Wellington, Bunnythorpe and Taranaki Generic Model | 1.0 | Wellington, Bunnythorpe and Taranaki Generic Model document |
To complete your FRT study, use the relevant case study and system assumptions. We provide Asset Owners with system assumptions on a case-by-case basis, so please contact us on [email protected] with your request.
Modelling Requirements
Asset models are crucial to the System Operator. Whether you are undergoing routine or ad-hoc testing, we have prepared GL-EA-716 Power Plant Dynamic Model Validation and Submission Prerequisites to help you understand the specific requirements that apply to your asset. We also provide the following to help with fulfilling the requirements:
New Connections
As part of connection studies, we examine unvalidated mathematical models of your asset to ensure they will be fit-for-purpose ahead of commissioning.
Once you complete the testing during commissioning, you will need to tune your power system models before validating them against your test results. Our GL-EA-716 document explains our requirements. The validated models help us to assess your plant’s impact on the wider power system by modelling your asset and its performance on our online and offline power system tools. We will then be able to create an accurate representation of the network, enabling us to maintain the reliability of the system.
If you have any questions about the modelling requirements that apply to your asset, email us at [email protected].