Single switched bays are considered vulnerable and are to be reinforced or replaced with urgency.
The three 500 kV circuits between Loy Yang Power Station and Hazelwood Terminal Station transmit power totalling 4GW from Loy Yang A, Loy Yang B, Valley gas power station and the BassLink interconnector. These circuits are pivotal to despatching and the single switched bays at both ends of the circuits are a priority for remedial action as part of this project.
Early works were completed in late 2017 to mitigate the failure risk of LYPS No.1 Line circuit at HWTS by repurposing the centre bay CBs in HWTS Bay 4 into a double-switch configuration, as the existing LYPS No.1 Line CBs and CTs were in poor condition.
Zinfra were contracted to replace three 500kV circuits between LYPS and HWTS with new double switch bays. Scope includes civil works relating to culverts and footing construction, primary and secondary electrical works and testing and commissioning of the new disconnectors, CVTs and CBs to the existing 500kV CB network.
Having worked with our civil partner, Civil Infrastructure Group at several sites in the Loy Yang and Hazelwood area, Zinfra were able to utilise their knowledge of local conditions and partner networks to develop a project schedule well-aligned with AusNet’s requirements to provide a low risk solution, negating any disruption to the power network.