An assessment method of power system harmonic impedance based on mixed total least squares

The assessment of system harmonic impedance is an important prerequisite for the evaluation of the harmonic emission level, the allocation of harmonic responsibility at a point of common coupling (PCC) and the design of the harmonic control device. Referring to the least square linear regression of harmonic impedance algorithm, this paper analyzes its error mechanism, influence factors and other issues; Furthermore, on the basis of the total least square linear regression method and comprehensive considering of voltage and current measurement errors, this paper optimizes the coefficient matrix and proposes a new method for calculating the system harmonic impedance based on the mixed total least square method; Finally, with IEEE 14-bus test system simulation based on PSCAD, the validity and accuracy of this new method is verified after comparing with the traditional methods.