A new method for harmonic impedance estimation

Determining the harmonic responsibilities of utility and customer side at a PCC has been a great concern in harmonic research, and utility harmonic impedance is a key factor for assessing harmonic emission levels. When background harmonic is unstable, traditional methods have a large error. A new method is proposed in this paper to assess harmonic impedance based on minimum energy fluctuation. The method can calculate harmonic impedance by constructing an object function which minimizes the background harmonic energy fluctuation, without assuming background harmonic is stable. Simulation analysis indicates that the proposed method is more reliable to calculate harmonic impedance, which can reduce the error caused by the fluctuation of background harmonic.