Phase angle error-based maximum correntropy adaptation for frequency estimation of three-phase power system
A robust technique based on maximum correntropy criterion (MCC) is proposed for frequency estimation in an unbalanced power system using error in phase angle. This is achieved by replacing the magnitude error used in the standard cost function of the MCC with the phase error and by extending the concept of the augmented (widely linear) complex statistics for the processing of unbalanced voltages and other abnormal system conditions. The idea emanates from the facts that: (i) useful information is primarily conveyed over the phase in power system frequency estimation, and (ii) the performance degradation of the well-known minimum mean squared error criterion based adaptive filters in impulsive noise environments can be overcome by the MCC due to the non-quadratic and higher order moments imbedded in its cost function. The proposed phase error-based MCC method also utilises all the second-order information within the complex valued system voltage through the Clarke's transformation. Simulation studies conducted using both synthetic and experimental data verify that the proposed algorithm provides better estimations compared to the considered algorithms.
