Power Harmonics Measurements Based on Modified Newton-Raphson Procedure

The paper proposes new algorithm for power harmonics parameters measurement based on modified Newton-Raphson method. The main modification is achieved through reconfiguration of the Jacobian matrix, and direct calculation of its characteristic coefficients without need to obtain inversion. The zero-crossing method is used to compute the frequency roughly for initial frequency estimation. With additional digital filtering, the parameters can be initialized properly and the updating steps can be supervised for fast convergence of Newton-Raphson iterations. With this combined approach, both high accuracy and good tracking speed can be achieved. It significantly reduces the computation complexity and makes the programming easier as well. The proposed algorithm has the quadratic convergence. Reliability and effectiveness of the proposed method was confirmed through simulation tests and results.