Asset test planning

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Participants should agree a test plan with the System Operator when they intend to perform system tests or tests to ascertain asset capability, and when the tests may impact on the System Operator's ability to comply with its Principal Performance Obligations (PPOs).

Examples of the types of tests include distributors conducting drop load tests and generators conducting reactive capability, load rejection or indication and measurement tests.

Asset owners are to use the Test Plan Form to notify the System Operator of their intention to conduct system tests. For routine and planned asset tests, the completed forms are to be submitted at least 15 business days in advance for approval. This allows the System Operator and asset owners to put in place any necessary operational plans to mitigate the effects of the tests. Where the required advance notice cannot be provided, you will need to contact the Duty Operations Manager.

If you are an asset owner and are unsure whether system tests will affect the System Operator's ability to comply with the PPOs, please consult the Duty Operations Manager on 07 843 0618

Modelling requirements

This guide is intended to provide direction to asset owners and their consultants about submitting mathematical models of power system equipment to the System Operator to ensure models are fit-for-purpose and appropriately validated prior to submission. This should help eliminate rework by asset owners, which can be a costly and time-consuming process.

Power system models

The following PSCAD EMT network models are provided for sections of the Transmission network in line with modelling requires set out in GL-EA-953. The models can be primarily used for fault ride through studies where an EMT study is required to be conducted, each model is supplemented with a supporting manual document.

Model for use in Grid Zone(s) Model Model Version User Manual
1,2,3 Northland Generic Model 1.0 Northland EMT model documentation
4 Edgecumbe Generic Model 1.0 Edgecumbe EMT model documentation


Datasets on the Electricity Authority’s website can be helpful with power systems analysis, these include Powerfactory case files and a readme text file detailing changes in the most current version.

These are available here:

Fault ride through testing

Details of the study case and assumptions required by asset owner’s to evaluate compliance against the fault ride through and temporary over-voltage envelopes has been published by Transpower, as outlined in clause 8.25A(3) of the Electricity Industry Participation Code.

For further information please contact us at [email protected].