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

� dial-up access to relays for engineering functions, event logs and fault recording data.
0BInvestment Evaluation Summary
TNM-GS-809-0720
This project will provide the following benefits that will ultimately improve the performance of the power system:
� better protection coordination with Aurora’s distribution network;
� better power quality monitoring and assessment;
� remote monitoring, interrogation and adjustment capability; and
� improved fault location leading to reduced outage duration.
The existing relays are a static type, which require testing at 3 yearly intervals. The proposed microprocessor type relays
have self-diagnostic features and require testing at 6 yearly intervals. This will result in operational savings and a
reduction in the risk of inadvertent system outages during the intrusive testing of the protection systems.
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.
The High Voltage Substation Protection Asset Management Plan (TNM-PL-809-0706) recommends that obsolete static
protection schemes be progressively replaced and where appropriate, be integrated with other planned works.
4.9 HV SCADA SYSTEM
The existing SCADA remote terminal unit (RTU) at Knights Road Substation is a Harris D20 installed in 1997 as part of
a program to remote control transmission substations. The Harris D20 RTU is not compatible with current IED
technology because it does not support TCP/IP connections and has limited serial connectivity. It is therefore important
that the SCADA scheme is replaced early in the project to ensure that new protection panels are able to appropriately
communicate alarms, events and controls back to Transend’s Network Operations Control System (NOCS).
Transend’s standard SCADA scheme incorporates a local area network (LAN) for engineering access to protection and
control devices. An Engineering PC connected to the substation LAN enables all devices to be interrogated for
disturbance records, fault locations and to undertake setting modifications. Connecting the Engineering PC to the WAN
allows these activities to be undertaken remotely.
A local human machine interface (HMI) PC will be installed at the substation. The HMI allows Field Operators to
control and monitor the substation in the event of loss of remote control from NOCs. The HMI is able to log substation
events at a higher resolution than can be sent back to NOCS, which is vital for post fault analysis.
Redevelopment of Knights Road Substation 110 kV provides the opportunity to cost-effectively install a modern,
reliable SCADA system that provides additional functionality and remote monitoring capability.
5 CUSTOMER CONSULTATION
Transend will liaise directly with relevant stakeholders regarding the intent, scope and implementation of the project.
The proposed redevelopment project has been highlighted on a number of occasions during Transend’s Annual Planning
Review process.
6 BENEFITS
The direct benefits of redeveloping Knights Road Substation 110 kV include:
� it will contribute to the achievement of the capital expenditure objectives identified in the Rules;
� provision of a safe, secure and reliable electricity supply to customers connected to Knights Road, Huon River and
Kermandie substations by replacing obsolete, unreliable assets that are in poor condition;
� life-cycle cost savings due to reduced operations and maintenance requirements;
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