Privacy-preserving spectral estimation in smart grid

Inter-area Oscillations pose serious threats to the stability of power transmission grids. Failure to notice or to handle inter-area oscillations may lead to widespread catastrophic blackouts. It is, therefore, critically important to monitor the oscillation conditions such that timely mitigation controls can be applied at the early stage. Recent research shows that it is an effective approach to continuously track the frequency domain of ambient phasor measurement units (PMU) data for the monitoring purpose. However, since inter-area oscillations usually involve multiple utility companies, tracking them requires PMU data from some different trust domains, which raises data privacy concerns. To address these concerns, we proposed privacy-preserving multiparty spectral estimation, which enables power grid operators to obtain the power spectrum of PMU measurement data, while the data remain encrypted. A case study was also carried out, which showed that the proposed scheme is secure, efficient, and practical.