A continuous-time least mean-phase adaptive filter for power system frequency estimation

The mean squared error criterion is widely used in the literature. However, there are applications where the squared error is not the primary parameter affecting the performance of a system. In this paper, we introduce a cost function that is based on the phase error. The criterion is useful for applications where the performance depends primarily on the phase of the estimated (recovered) signal. A continuous-time adaptive filter is then developed using the proposed criterion in stochastic differential equation formalism. The proposed adaptive filter is used to estimate power system frequency where the formulated structure is very simple. The three-phase voltages are converted to a complex form for processing by the proposed algorithm. The performance of the new algorithm is studied through simulations at different situations of the power system.