Request for Tender (RFT) for the Tasmanian Integrated System Protection Scheme (TISPS)

TasNetworks is seeking submissions for the Tasmanian Integrated System Protection Scheme (TISPS) . Further details are provided in the attached RFT document pack, please review all documents in the pack starting with the RFT Overview Document. Scope: The System Protection Scheme (SPS) was first introduced in 2005 to facilitate Basslink by maximising the capacity of the transmission network. This reduced the risk to the network following a contingency involving Basslink. Now the SPS is approaching it’s end of life requiring replacement and redesign to facilitate the upcoming network augmentations to meet the legislated Tasmanian Renewable Energy Target (TRET). The purpose of the RFT is to ensure the replacement and redesign of the System Protection Scheme (SPS)hardware and software to support the establishment of the Tasmanian Integrated System Protection Scheme (TISPS), ensuring any future arrangements can be accommodated. Purpose: This document supersedes and updates the existing SPS design documentation [1], [2]. The update is required due to: 1. End-of-life replacement requirements for existing SPS hardware; and 2. The development and anticipated commissioning of the ML, being Tasmania’s second HVDC interconnector. This document also applies to associated plant and equipment located at power stations, customer sites and TasNetworks substations where such plant forms part of, or materially affects, SPS performance. This document also represents a major upgrade of the 2005 SPS Operational Requirements report [13] and incorporates: • Requirements introduced through the current SPS Performance Standards [2]; • Anticipated changes in generator and load participation; • Revised contingency sizes; • Modified network flow patterns; and • Learnings derived from actual SPS operational performance. Information from the 2005 SPS Performance Standard [14] have been revised to reflect the changed operating environment associated with ML commissioning and significant expansion of wind and solar generation and is now incorporated within this document - the broader SPS Functional Specification framework. This document addresses SPS operation under both credible contingencies, including loss of a single transmission circuit or interconnector, and non-credible contingencies, including multiple circuit or interconnector outages. It identifies required remedial actions, defines response times, and specifies required redundancy and back-up protection arrangements. The existing SPS historically comprised two principal schemes: • Frequency Contingency System Protection Scheme (FCSPS); and • Network Contingency System Protection Scheme (NCSPS). The terminology has been updated to replace the term “Control” with “Contingency” to reflect scheme purpose and operation more accurately. The development of ML materially changes the Tasmanian system security framework. The presence of multiple HVDC interconnectors significantly increases transfer capability and introduces enhanced run-back/run-upfunctionality. As a consequence, generator contingencies greater than the current Largest single contingency event in Tasmania may now be managed through the SPS framework. This has led to formal incorporation of the Generator Contingency System Protection Scheme (GCSPS) into the SPS architecture. The upgraded SPS is designed to achieve the following: • Continue to support BL transfers of up to 630 MW northward and 480 MW southward (measured at George Town station), subject to system security constraints; • Enable ML transfers of up to 750 MW from either receiving station under normal operation; • Permit ML overload operation up to 900 MW from either receiving station for up to 20 minutes (within a 60-minute overload window) under specified contingencies, including BL outage; • Provide coordinated HVDC run-back and run-up control signals in response to contingencies; • Enhance supervision of transmission corridors within the Palmerston-Sheffield-George Town triangle, including the new double-circuit Palmerston-Sheffield connection; • Facilitate increased generator contingency sizes beyond the Largest single contingency event in Tasmania under defined conditions; • Integrate the George Town Reactive power SPS (GTRSPS) into the NCSPS operational framework; and • Maintain architectural flexibility to accommodate future mainland interconnectors without requiring replacement of the SPS platform. Without the SPS, interconnector transfers and intra-state network utilisation would be constrained to Firm transfer levels, resulting in material limitations on generation dispatch and network capability. The upgraded SPS introduces increased redundancy and diversity including: • Fully duplicated SPS central assets; • Main 1 + Main 2 tripping arrangements; • Duplicate and diverse communication channels; and • Layered back-up schemes including UFLS, OFGS and transmission circuit overload protection. Operation of the SPS requires duplicate TasNetworks communication systems. Where one communications system is unavailable, interconnector flows, selected AC flows and any generation above the Largest single contingency event in Tasmania shall revert to Firm transfer levels within three to four dispatch intervals. An exception applies to ML interstation communication loss, where single-channel operation may be permitted for up to the Allowed maintenance period subject to defined conditions. Ensure in your submission you address all the requirements listed in the RFT Response Schedule and Technical Standards, which are included in the document pack, along with any other supporting documentation and annexures. Responses are requested in Excel, Word and Portable Document Format (PDF) and must be lodged in the electronic tender box set up for this RFT by the closing time 2:00pm AEDT Monday 10th August 2026. Please ensure to WinZip all the documents into one (1) WinZip file to upload your submission. Please allow sufficient time to up-load responses. An online forum has been set up on the site for all questions to and replies from TasNetworks. Questions must be posted solely via this forum. The forum closes five (5) days prior to the RFT closing time. No direct contact is to be made with any TasNetworks Representative during this Tender process. Tender Briefing: 21 July 2026 – 08:30 AM – 10:30 AM AEST. Important: The Tender briefing will be held online exclusively. Although not mandatory, we strongly encourage all interested Tenderers to attend to have a better and more complete understanding of the Tender requirements. To participate and receive the MS Teams invitation, please send an email to Tenders@tasnetworks.com.au confirming your Company’s attendance including full names, positions and email addresses of the representatives attending. A maximum of two (2) representatives per company is allowed. Emails should be sent by COB, 19 July 2026. TasNetworks will respond to the email you sent providing the link for the meeting via MS Teams. Please refrain to do any forum questions or requests for this Tender until the Briefing is held, as the briefing might respond to many of them.