VIRTUAL STORAGE
Demand management is a form of ‘virtual storage’. Shifting a large load from one time to a later time has the same effect on an electricity network as using a large battery to store excess power and deliver that power at a later time.
Flexible demand as a virtual energy storage system
The goal of this subtheme is to develop a cost-effective way to use a virtual energy storage system (i.e. grid loads with flexible demand) that is as reliable and responsive as a large fleet of batteries, based on five objectives: 1. Develop models for a virtual energy storage system via local intelligence, which can ensure customers’ comfort constraints, while simultaneously providing reliable service to the grid; 2. Estimate real-time virtual energy storage system capacity as a function of customer comfort constraints; 3. Reveal cost and customer comfort trade-off curves for creation of market incentives for consumer engagement; 4. Propose local robust control at each virtual energy storage system as part of an overall distributed control architecture; and 5. Build prototype hardware for validation.
Power modulation of aluminium smelting cells for power demand-supply balancing
The aluminium smelting process is very energy intensive, with Australia’s smelting industry consuming 22.8 TWh of electricity in 2018. On its own, the Tomago smelter operated by the Tomago Aluminium Company consumes 12% of total electricity in NSW. Existing aluminium smelting operations typically operate at constant current levels to reduce the variability of the smelting process and simplify process operation. However, this approach results in little flexibility in power modulation of smelting cells. There are major challenges in power modulation of aluminium smelting cells. Variable amperage may lead to significant problems in heat balance of the cells and current efficiency, and abnormal conditions may occur if the smelting cells are not tightly controlled. In collaboration with industry partners, new smelting process operation strategies, and cell monitoring and control approaches will be developed to allow flexible power modulation. This will enable the production rate of aluminium to be reduced or increased to match the supply of power and/or electricity prices. Such virtual storage can provide significant benefits to the stability and efficiency of the electricity network while reducing operating costs for aluminium producers. Research will be focused on: 1. Studying the feasible operation ranges that minimise irreversible damage to smelting cells based on coupled thermal and mass balance of the smelting cells; 2. Cell monitoring approaches that can detect and thereby avoid any abnormal operation conditions caused by power modulation, including using individual anode current measurements, and 3. Advanced process control approaches for tightly controlling operation of smelting cells with varying current, based on multi-variable control and nonlinear multi-stage state observer.
PROF JIE BAO
Theme Leader
Professor Jie Bao is a Process Control expert, particularly in dissipativity/passivity based process control. He leads the Process Control Research Group, School of Chemical Engineering.