System Operations responses to MAN review recommendations (July 2015)
System Operations group responses to the recent Manapouri outage review recommendations.
Delivery will be overseen by Andrew Gard and Dan Twigg.
Summary of Recommendations
1. Involve system operator in Project Atlas to initiate improvements to IONS from an outage
planning perspective (Section 3.2, Page 19).
o SO to work with Transpower planning personnel to identify and implement suitable
changes to IONS that will improve planning outcomes. IONs improvements are likely to
be identified by June 2016 and implemented in the 2016/17 year.
2. Develop and operationalise a policy for the management of busbars as an ECE risk for cascade
failure and/or frequency events (Section 3.2, Page 19).
o SO has established an internal project to address implementation of the policy requiring
busbar outages to be considered as ECE risks. Target completion is December 2015 for
phase 1 of the project (establish an interim policy and review the ECE classification
methodology) and recommended if any classification methodology changes are
required). The timeline for subsequent phases will be determined in December 2015.
3. Review and update the SSF (Section 3.2, Page 19).
o Reference to treatment of MAN bus will be incorporated in the SSF review later in 2015.
o After completion of the busbar ECE implementation (2, above) the next following SSF
update will incorporate any needed changes.
4. Review and correct the “Credible Event Review” (2014) document (Section 3.3, Page 20).
o Website copy has been updated.
5. Establish the status and ownership of the “Extended Contingent Event (ECE) Categorisation"
(dated 2010) document (Section 3.3, Page 20).
o To be revised as part of the project in 2, above.
6. Review (by the Engineering and Markets teams) of the voltage stability constraint built for this
outage and the design process that was used to build it (Section 3.4(a), Page 21).
o To be internally reviewed. Target completion is November 2015.
7. Consider the involvement of market participants in a more inclusive relationship when detailed
outage planning is carried out to provide better information to the market and to understand
and consider market solutions to mitigation measures (Section 3.4 (b), Page 23).
o Changes in planning process to be considered by SO Operations Planning team with a
view to including participant input. How and when to be considered. Target completion
is October for developing an action plan, and December 2015 for implementation.
8. Investigate and implement the release to market participants of generation and load
agreements, either in their original form or in a condensed format (Section 3.4 (c), Page 23).
o Arrange publication of load and generation agreements. Legal sign off has been
obtained. Customer agreement to be secured. SO will work with Transpower planning
personnel to address publication concept.
o Improve the fitness for purpose of load and generation agreements. SO will work with
Transpower planning personnel to address this requirement as part of current
Transpower grid change initiatives.
9. Investigate and rectify the customer agreement with NZAS for the number 4 pot-line filter
(Section 3.4 (c), Page 24).
o
Investigate how planners were unaware Tiwai F4 was unavailable and consider if Tiwai
F4 is required for normal power system operations. Target completion September
2015.
10. Establish an "Outage Governance Group" consisting of Senior and/or Executive Management
from both the System Operator and Grid owner (Section 3.5, Page 25).
o This recommendation has in-principle Transpower support from System Operations.
Establishment will be considered as part of current Transpower grid change initiatives.
11. Investigate better work sharing between the system operator’s Planning & Support team, the
System Security team, and the Engineering team (Section 3.6 (a), Page 25).
o This recommendation is not supported by Transpower. While it is accepted the outage
planning did not proceed in a desirable manner and time frame this situation was not
caused by the ‘compartmentalisation’ of System Operations group’s team skills. A major
contributing factor (amongst other things) was, as noted in the review, an overall
shortage of planning resources. A variety of skills across the engineering and real time
teams were applied to planning the outage. The reviewer’s opinion will, however, be
taken regard of in future, especially when difficult or market-sensitive outages are being
planned.
12. Reduce the outage churn rate by educating the grid asset owner about implications of outage
date changes; freeze the 4 week out outage plan; ensure the grid owner’s project managers
liaise with system operator at an early stage in the development of their project schedules
(Section 3.6 (b), Page 26).
o This recommendation has strong in-principle support across Transpower. A number of
significant changes to the planning process will occur arising from the current
Transpower grid change initiatives, including reducing outage planning churn. These
changes are being developed and trialled at the present time and will be introduced
during the year.