NMIR Project Deployment Supporting Information and Resources

National Market for Instantaneous Reserves - Background

On 20th October 2016 Transpower deployed the National Market for Instantaneous Reserves (NMIR) project, a joint initiative between Transpower and the Electricity Authority.

The project was part of the Reserves and Frequency Management Programme and introduced changes required to create a national market for reserves by allowing reserves to be procured in one island to cover generation risk in the other.

Software Specifications

Transpower as System Operator provides software specifications for core market system solvers.  Software specifications are used as the basis for software audits and by industry participants to assist in their understanding of how the Wholesale Electricity Market functions.

RMT Specification

This document is the functional specification for the System Operator’s Reserve Management Tool (RMT). This application software is used by the System Operator to calculate the instantaneous reserves required to meet the Reserve Management Objective.

Voltage support

Voltage support is provided by generating units or static equipment capable of producing or absorbing reactive power. This is done to maintain voltages on the system within Code limits.

We may enter into voltage support contracts with parties who can offer voltage support compliant with our technical requirements and the Code.

Voltage support is procured on a firm quantity procurement basis (via a monthly availability fee and/or a single event fee for a specified MVAr availability).

Instantaneous reserve

Instantaneous reserve is generating capacity, or interruptible load, available to operate automatically in the event of a sudden failure of a large generating plant or the HVDC link.

This service is required to stop the resulting fall in frequency and allow the system frequency to recover promptly to 50 Hz.

We enter into instantaneous reserve contracts with participants who can offer instantaneous reserve compliant with our technical requirements and the Code.

Instantaneous reserve is procured on a half-hour clearing market basis.

Special Protection Systems


Special Protection Schemes are means by which circuit loadings, voltage or frequency can be controlled after an event on the power system which might otherwise cause an overload of transmission equipment (eg circuit or transformer).

The following is information that we have published on special protection schemes

Excursion Notices

Excursion notices are emailed out to registered electricity market participants and comprise of the following notice types and :

  • Frequency Excursion Notices
  • Voltage Excursion Notices

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