Transend - Appendix 5 Renewal capital expenditure - Australian ...

0BInvestment Evaluation Summary
TNM-GS-809-0720
The new microprocessor based protection schemes will provide in-built disturbance recording features that enable easy
post-fault diagnosis and faster outage restoration. These features will reduce ongoing operational costs associated with
fault investigations. The installation of remote interrogation facilities will also reduce operational expense of uploading
these disturbance records.
4.5 GOOD INDUSTRY PRACTICE
In recent years, most of utilities in Australia have been systematically replacing protection and control systems of an
obsolete design with new digital devices. Past experience has shown that protection and control upgrades have
significantly enhanced transmission network reliability and plant availability.
It is expected this trend will continue for the next few years until all legacy secondary systems are replaced with modern
technology.
5 CUSTOMER CONSULTATION
Transend will liaise directly with relevant stakeholders regarding the intent, scope and implementation of the project.
6 BENEFITS
The successful implementation of the New Norfolk Substation 110 kV Protection Replacements project will provide the
following benefits:
� it will contribute towards the achievement of the capital expenditure objectives;
� the risk of unplanned outages due to secondary system failures will be reduced, thereby improving the reliability
of the transmission network;
� the occurrence of events that cause power flows through the substation to be constrained will be reduced;
� the new protection systems will ensure compliance with the Rules;
� obsolete, unreliable and maintenance intensive protection and control devices will be replaced with modern,
reliable equipment that incorporate self supervision functions, thereby reducing ongoing operations and
maintenance costs;
� spares will be made available for secondary assets at other substations;
� additional disturbance recording and fault location equipment will be provided, thereby improving power system
analysis and fault response capability; and
� the new secondary systems will adequately cater for planned future works with minimal re-work.
7 OPTIONS ANALYSIS
The following viable options have been considered for the New Norfolk Substation 110 kV Protection Replacement
project:
1. maintain the existing assets and defer replacement; and
2. undertake the identified works as an integrated project.
The option to undertake the identified works on an individual project basis was considered but was discounted because it
is clearly not a cost-effective approach.
These options are discussed in further detail in the following sections.
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