A Robust Regularized Hybrid State Estimator for Power Systems |
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Authors: | Sanjeev Kumar Mallik Saikat Chakrabarti Sri Niwas Singh |
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Affiliation: | Department of Electrical Engineering, Indian Institute of Technology Kanpur, Kanpur, India |
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Abstract: | Abstract—Numerical instability is an inherent issue with power system state estimation, and much effort has been made to overcome this issue using numerical techniques to ensure stability. This article proposes a regularization-based method for solving ill-conditioned hybrid state-estimation problems in the presence of equality constraints. The iterative linear state-estimation problem is solved by using Tikhonov regularization. The trade-off between the residual norm and the regularized norm is controlled by the regularization parameter in the regularization method. The regularization method employs an L-curve criterion for optimal selection of the regularization parameter. At the post-estimation stage, the correction in voltage phasor at the zero-injection bus is applied using Kirchhoff's current law. The proposed method is analyzed and tested for IEEE 14- and 118-bus test systems, as well as for a 13-bus ill-conditioned system. |
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Keywords: | hybrid state estimation ill-conditioned matrix condition number LU factorization regularization L-curve singular value decomposition |
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