Mr Lakshan Bernard
DATA-DRIVEN SECURITY ASSESSMENT OF RENEWABLE-RICH POWER NETWORKS
Mr Lakshan Bernard
3rd year, PhD Candidate, Electrical and Computer Systems Engineering, Monash University (Zema Scholar)
Research interests: system strength, subsynchronous control interactions, applied statistical tools, situational awareness in power networks and synchrophasor networks
Lakshan received his BE (Hons) degree in Electrical and Computer System Engineering from Monash University, Australia in 2019. Currently, he is working towards a PhD degree in Electrical Engineering at Monash University and is being co-supervised by Dr Reza Razzaghi from the Department of Electrical and Computer Systems Engineering and Professor Rob Hyndman, Head of the Department of Econometrics and Business Statistics in the Monash Business School.
The PhD is sponsored through the Zema Scholarship Fund by the Australian Energy Market Operator. Lakshan’s research exemplifies the critical role of engineering research in designing and developing the technical solutions needed to optimise our power networks and increase inverter based generation while maintaining system security.
When Lakshan started his PhD in 2020, the oscillations in the West Murray region were breaking news. Through correspondence with AEMO, he learnt that system strength was currently a limiting factor in the uptake of renewable energy. Moreover, the academic literature on system strength was constantly evolving. It was the perfect opportunity for Lakshan to research an interesting topic that would also be helpful for AEMO. As with any new topic, there is some healthy debate regarding definitions: what exactly is system strength? how do we quantify it? what happens if there is not enough system strength?
One of the common manifestations of lower system strength are persistent sub-synchronous oscillations in the system. Lakshan is interested in how such oscillations can be monitored using data driven methods. He has proposed a novel algorithm for Phasor Measurement Units (PMUs) that would allow them to monitor non-fundamental frequencies and estimate the damping.
Currently, the focus of his research is on how they can screen the grid for regions of low system strength. “The rapid uptake of renewable energy is great from an environmental perspective; from an engineering perspective, we want to ensure that the grid remains stable and secure. To achieve this, it is essential that we are proactive in finding regions where Inverter Based Resources (IBRs) may interact undesirably. The current screening tools are used heuristically, and as such, there is room for improvement. I am working on designing and testing a metric that is based on the underlying physics of the system that is more accurate and interpretable than the current state of the art.”
Lakshan’s research is multidisciplinary because often the exact parameters of a physical system are unknown, thus the need to use statistics. However, the use of statistics must be judicious to ensure that the results remain interpretable. “As such, my research has greatly benefitted from the multidisciplinary aspect of the Zema Energy Studies Scholarship.
My future work is to test out the novel screening metric on the NEM and SWIS. It will be interesting to see how the system strength changes for different uptakes of IBRs, and the sooner we identify regions of low system strength the better. I also hope to further my research on PMUs, in particular, how measured data can be used to augment the system strength screening process.”
After submitting his current paper, the academic direction for the third year of his PhD is to combine the work in his first paper (on PMUs) with the system strength screening. “An interesting idea is to use the PMU measured data to update the parameters of the state space model to improve accuracy of the screening. This would also give my overall thesis a cohesive theme. I am also extremely interested to see how my proposed screening method works on the National Electricity Market (NEM) or the South West Interconnected System (SWIS). Following my PhD, I would like to apply my research on real power systems.”
Lakshan is also part of the following academic research groups: