Townsville, Australia: Hybrid RGS conversion to alternate between power production and grid stability mode

With the rising share of renewables in Australia’s energy mix, grid stability from rotating equipment has substantially decreased. Therefore, the Australian Energy Market Operator (AEMO) requires grid operators like Powerlink to provide a minimum fault level and procure system strength. After reviewing eight different possible solutions, Powerlink concluded the addition of a clutch to the shaft between the gas turbine and the synchronous generator at the Townsville Power Station (TPS) was the least-cost option to address the shortfall and entered into a System Strength Services Agreement with TPS for the provision of system strength services.

Siemens Energy will provide integrated service solutions to convert the gas turbine to a Hybrid RGS during a scheduled major outage in 2025. Replacing the intermediate shaft of the gas turbine with a Synchro-Self-Shifting (SSS) clutch will provide an instantaneous switch from power generation to synchronous condenser mode. When in synchronous condenser mode, the Hybrid RGS unit can provide rotating inertia and short-circuit power without the need to produce power and is calculated to provide a short-circuit contribution of approximately 350 to 400 MVA. The electrical inertia while operating in the grid stabilization mode is calculated to be around 250 megawatt seconds (MW.s) and around 1,000MW.s while operating in power generation mode.

It will be Siemens Energy's first project in Australia to convert an operating gas turbine unit to a Hybrid RGS. The project also marks the first Hybrid RGS conversion project on this size of gas turbine worldwide.