Frequency‐Shift‐Based Optimisation Strategy for Passive Power Filters to Mitigate Harmonic Resonance in Multi‐Scenario Distribution Networks

ABSTRACT

In this study, an optimal filter design method was developed to address system uncertainties in distribution networks. Harmonic characteristics were modelled under multiple operating scenarios to account for variations arising from component parameter deviations, intermittent renewable energy generation, and load fluctuations. Harmonic modal analysis was conducted to estimate resonance shifts associated with deviations in filter component parameters. A multi‐objective bat algorithm (MOBA) was employed to optimise filter parameters, with the objectives of minimising total harmonic distortion (THD) in voltage and current, improving the power factor, and reducing installation costs. Design constraints were formulated to ensure compliance with harmonic standards, including limits on individual harmonic distortion levels, reactive power support requirements, and resonance risk under component parameter deviations. The proposed method was validated using the IEEE 33‐bus distribution system. During daytime operation, when the solar plant served as the primary harmonic source, a current THD (THDI) of 28.91% and a voltage THD (THDV) of 15.26% were observed at the point of common coupling. After the installation of the proposed passive power filters, the THDI was reduced to 0.74% and the THDV to 2. 51%, corresponding to reductions of approximately 28 percentage points and 13 percentage points, respectively. All harmonic indices were brought within IEEE 519 limits, confirming the effectiveness of the proposed approach.