Frequency tracking techniques of power systems including higher order harmonics

A novel technique for tracking the frequency of power systems with high order harmonic based on numerical differentiation and digital FIR filter is presented in this paper. A low-pass FIR filter is used to decompose the non-sinusoidal signal into fundamental sinusoidal component, and numerical differentiation is used to compute the frequency of power systems. The proposed algorithm can track the frequency of power systems in half cycle and show better characteristic of simple computation, high accuracy and less time comparing with the existing techniques. A study example is given to illustrate the proposed algorithm in Matlab.