Today, I learnt that my journal paper was accepted for publication in IEEE Transactions on Smart Grid (TSG) wich has an impact factor of 4.25. Co-authors were Fred Popowich, Ivan V. Bajic, Bob Gill, and Lyn Bartram. This paper is an expansion of my PhD thesis which and discusses an improved HMM-based NILM algorithm. Here is the abstract:
Understanding how appliances in a house consume power is important when making intelligent and informed decisions about conserving energy. Appliances can turn ON and OFF either by the actions of occupants or by automatic sensing and actuation (e.g., thermostat). It is, also, difficult to understand how much a load consumes at any given operational state. Occupants could buy sensors that would help, but this comes at a high financial cost. Power utility companies around the world are now replacing old electro-mechanical meters with digital meters (smart meters) that have enhanced communication capabilities. These smart meters are essentially free sensors that offer an opportunity to use computation to infer what loads are running and how much each load is consuming (i.e., load disaggregation). We present a new load disaggregation algorithm that uses a super-state hidden Markov model and a new Viterbi algorithm variant which preserves dependencies between loads and can disaggregate multi-state loads, all while performing computationally efficient exact inference. Our sparse Viterbi algorithm can efficiently compute sparse matrices with a large number of super-states. Additionally, our disaggregator can run in real-time on an inexpensive embedded processor using low sampling rates.
Keywords: load disaggregation, nonintrusive load monitoring, NILM, energy modeling, hidden Markov model, HMM, sparsity, Viterbi algorithm, sustainability.