Loop frame of reference based harmonic power flow for unbalanced radial distribution systems

•A new harmonic power flow for radial distribution power systems is proposed.•The proposed method is based on the loop-frame of reference.•The proposed method is at least 18% faster than the Gauss Implicit Zbus Method.

In this paper, a three-phase harmonic power flow method for unbalanced radial distribution systems is proposed. The proposed method is based upon the loop frame of reference, rather than the conventional bus frame of reference. In addition, an injection current technique is also applied in the proposed method. The proposed method can be used for both fundamental and harmonic power flow studies. Four three-phase IEEE test feeders are used to prove the accuracy and efficiency of the proposed method. The test results show that the proposed method is robust and reliable for passive power filters set design, especially for full-scale distribution systems.