Modal analysis of power systems with eigendecomposition of multivariate autoregressive models

Analysis of electromechanical modes provides substantial information regarding the power system stability. This paper introduces a novel approach to the measurement based modal analysis of power systems by using a multivariate autoregressive model (MAR). The MAR model utilizes data that are simultaneously measured from several locations in the power system through a wide area monitoring system (WAMS). The performance of the MAR model is analyzed by applying it to data generated with a 39-bus New England test system. In addition, the model is utilized for analyzing data generated with a detailed simulation model of the Nordic power system. The results indicate that the frequencies and damping ratios of electromechanical oscillatory modes can be accurately analyzed with the eigendecomposition of the MAR model. Thus, the MAR model is a promising identification technique for wide-area monitoring of electromechanical oscillations.