Real Time Phasor Estimation Based on Recursive Prony with Several Channels of One PMU

Abstract

Phasor estimation is crucial for monitoring and control of smart power systems. The classical signal processing method named Prony has been used for estimating the parameters of measured signals such as frequency, damping factor and phasor. To reduce the impact of noise on the parameters estimated by Prony, multi-channel Prony has been previously explored and presented in the literature. The basic approach for multi-channel Prony is a generalized solution, in which new rows are added to matrices for every channel. Since the generalized multi -channel Prony is time-consuming, a new method based on recursive solution is proposed in this paper to make it suitable for real-time application. Here, several channels of one Phasor Measurement Unit (PMU) are used to estimate the phasor of current/voltage in a recursive pattern, in which the phasor is computed recursively over time based on previously calculated estimates and new measurements. The proposed method is compared with three other solutions for multi-channel Prony: a) data fusion which is based on the Kalman filter concept, b) an alternating direction method of multipliers (ADMM), and c) a consensus update approach which is based on an iterative procedure. Simulation results demonstrate the ability of the proposed method for real-time phasor estimation, both in terms of maintaining the accuracy and reducing computation time.