1.Electrical Engineering College of Sichuan University,Chengdu;2.State Grid Sichuan Electric Power Research Institute,Chengdu
All the existing quantification methods of harmonic responsibility of distributed multiple harmonic sources use the external port current (hereinafter referred to as the port current of harmonic source) of the harmonic source equivalent circuit (Norton equivalent model in common use) to calculate the harmonic contribution of the harmonic source to the concerned bus. Since the harmonic source port current is constrained by the Kirchhoff’s law, as long as the harmonic source port current changes in the power grid, the harmonic contributions of all harmonic sources to the concerned bus will change accordingly. However, the harmonic source port current is usually the result of the coupling of harmonic source and background harmonic, so the harmonic contributions calculated by this current cannot truly reflect the harmonic emission level of the harmonic source. Therefore, this paper quantifies the harmonic responsibility of each harmonic source to the concerned bus by harmonic source current itself rather than harmonic source port current. The proposed method directly solves the complex harmonic voltage contribution of each harmonic source to the concerned bus, and it does not need to solve the harmonic transfer impedance of the harmonic source to the concerned bus, which reduces the effect of cumulative errors, can more fairly and reasonably reflect the harmonic responsibility of each harmonic source. The effectiveness and accuracy of the proposed method are verified by simulation and experimental example.