Event detection in electrical grids is a challenging problem for machine learning methods due to spatiotemporally nonstationary systems and the inability to automate event labeling in high-volume data such as PMU measurements. As a result, the existing historical event logs created manually do not correlate well with the corresponding PMU measurements due to scarce and temporally imprecise labels. Trying to overcome this problem by extending event logs to a complete set of labeled events is very costly and often infeasible. We focused on utilizing a transfer learning model to reduce the need for additional data labeling by leveraging some labeled data instances available from a small number of well-defined event detection task. To demonstrate the feasibility, we tested our approach on a large dataset collected by 38 PMUs from the Western Interconnection of the U.S.A. over two years. The model evaluation performed based on varying percentages of labeled source data corresponding to ~20-700 characteristic events on different sizes of time windows ranging from 2-seconds to 1-minute demonstrates that the developed method can significantly improve automated event detection based on PMU measurements when extensive labeling is costly or impossible to obtain. When compared to the state-of-the-art machine learning algorithms (unsupervised, semi-supervised, and supervised), the results show that the transfer learning method has significantly better performances when detecting events by learning from as low as 20 representative labeled data instances.

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A novel method for real-time solar generation forecast using weather data, while exploiting both spatial and temporal structural dependencies is proposed. The network observed over time is projected to a lower-dimensional representation where a variety of weather measurements are used to train a structured regression model while weather forecast is used at the inference stage. Experiments were conducted at 288 locations in the San Antonio, TX area on obtained from the National Solar Radiation Database. The model predicts solar irradiance with a good accuracy (R 2 0.91 for the summer, 0.85 for the winter, and 0.89 for the global model). The best accuracy was obtained by the Random Forest Regressor. Multiple experiments were conducted to characterize influence of missing data and different time horizons providing evidence that the new algorithm is robust for data missing not only completely at random but also when the mechanism is spatial, and temporal.

Electric power system operators monitor large multi-modal data streams from wide service areas. The current data setups stand to get more complex as utilities add more smart-grid sensors to collect additional data from power system substations and other in-situ locations. We propose a methodology to utilize multi-modal data for automated power system fault prediction, and precursor discovery that takes advantage of not only the utility owned measurements but also an abundance of data from other related databases such as weather observation systems. The process is automated to help operators analyze multimodal data that may be impossible to process manually due to the size and variety. We automatically preprocess multi-source data and learn a joint latent representation from collocated streamed, sparse, and high-dimensional data collected from Phasor Measurement Units and external weather data. Then we utilize multi-instance learning to predict events and discover precursors simultaneously without relying on post-mortem studies of fault signatures. We apply the proposed methodology to provide early predictions of faults in the U.S. Western Interconnection. AU-ROC of 0.94 is achieved in predicting events by utilizing information 5 hours before event time using season-specific models. We show how precursors can be extracted from multi-modal data and interpreted for predicted events.INDEX TERMS Big data, weather, event detection, event precursors, machine learning, phasor measurement units, power system faults, smart grids, time series analysis.