AUFLS describes the set of relays in New Zealand which automatically trip blocks of load, following a severe under-frequency event, to restore the system frequency.
Transpower, as the System Operator relies on these relays to prevent system collapse following under-frequency events which have the potential to cause a system black-out.
New Zealand's current AUFLS scheme is made up of two blocks of at least 16% of demand in each island. This means that 32% of customers' load can automatically disconnect to restore stability to the power system following the loss of net injection which drops the system frequency to below 48 Hz.
To improve overall performance and therefore reliability of the scheme, the System Operator and the industry will be moving to a four block AUFLS scheme, which the Authority anticipates will be in place by June 2025. See the AUFLS Project page for more information on the project.
AUFLS Animation/video
We have prepared a two sets of animations/videos:
- the first one summarises the findings of the AUFLS Scheme Design Report and is available here.
- the second is a set videos shows how to use the AUFLS Data Portal and is available here.
AUFLS Project
Transpower is in the process of transitioning to a four block scheme. The first phase of the project is currently underway and is focusing on establishing a data portal for North Island Distributors to be able to submit their two block AUFLS data to the system operator. Refer the AUFLS Project web page for more information.
Related Documents
Document | Description |
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Distribution Assets Testing Guide | |
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This document sets general requirements of routine testing that apply to all testing that is carried out on assets prior to commissioning and for testing after any modification. |
AUFLS Customer Portal – User Guides and FAQs | |
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A user guide for Distributor users of the AUFLS Portal (a copy is also available in the portal itself). |
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A guide to accompany the data templates which provides detail on how to populate these. |
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A document that covers key messages and frequently asked questions relating to the AUFLS Project |
AUFLS Customer Portal – Forms and Templates | |
Link to Customer Portal | |
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A form that the Distributor uses to nominate the Admin users that they would like to be initially created in the portal. |
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An excel template for Distributors to populate the location, configuration and status of AUFLS feeders for the submission period. |
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An excel template for Distributors to populate the average load (MW) at each AUFLS feeder for each trading period over the specified 12-months period. |
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An excel template for Distributors to populate the average off-take load (MW) at each GXP for each trading period over the specified 12-months period. |
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An excel template for Distributors to populate the total load (MW) for each trading period over the specified 12-months period. |