An Estimation Method to Determine Equivalent Circuit Parameters for the Harmonic Analysis

Abstract

This paper proposes a new estimation method to determine any circuit parameters for the harmonic analysis of distribution network. The harmonic analysis is important to maintain quality of electric power. An interesting phenomenon, which is the cut-down of harmonic voltage level temporarily at dawn even if demand is a little bit increasing at this time, is often observed in the actual power system. This paper proposes utilizing the observation results of this phenomenon to estimate circuit parameters. In addition, this paper claim that detail equivalent circuit is more preferable for explaining that phenomenon than conventional simplified equivalent circuit. This paper also discusses the usefulness of the Harmonic Characteristics Curve, which is the proposed by this paper as new concept, at secondary winding of distribution transformer and the correlation of PQ, which are monitored values of active and reactive power at secondary winding of distribution transformer. This correlation should determine the equivalent fundamental frequency admittance of among of the shunt capacitors installed concerning distribution lines.