Factors and Effects of Harmonic Resonance in Medium-Voltage Distribution Networks with High Photovoltaic Penetration

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🔬研究者:Provides a modeling approach for harmonic resonance in PV-rich networks, useful for further studies on grid stability and power quality.

🏢実務担当者:Offers a method for preliminary resonance risk assessment, applicable for distribution network planners and engineers dealing with high PV penetration.

The increasing penetration of inverter-based renewable energy sources and the growing share of cable sections in modern power distribution networks significantly modify the frequency-dependent characteristics of power systems and increase the risk of harmonic resonance phenomena. This issue is particularly relevant for highly branched medium-voltage distribution networks with combined overhead and cable feeders, where the changing ratio between inductive and capacitive parameters may lead to resonance conditions, increased harmonic distortion, maloperation of protection systems, equipment overloading, and deterioration of power quality. This paper presents an analysis of harmonic resonance in 20 kV distribution networks using an equivalent model based on lumped inductive and capacitive parameters. The proposed model takes into account the influence of overhead and cable lines, transformer inductance, photovoltaic inverters, and the short-circuit power of the supplying substation. A real-case example of a medium-voltage distribution network with combined overhead and cable sections and integrated photovoltaic generation is also presented. Frequency-domain analysis is performed under different operating conditions, including variations in cable line length, increasing installed photovoltaic capacity, and reduction of the short-circuit power of the supplying system. The obtained results demonstrate that increasing the equivalent network capacitance and weakening the supplying system shift the resonance frequency toward lower-order harmonics and increase the likelihood of harmonic voltage and current amplification. It is established that the most unfavorable operating conditions occur under the combined presence of high photovoltaic generation, low daytime loading of distribution transformers, and limited short-circuit power at the supplying substation. The proposed approach can be used as an engineering method for preliminary assessment of harmonic resonance risk during the planning and operation of modern power distribution networks.

• Research Square https://doi.org/10.20944/preprints202605.1783.v1first seen 2026-06-04 04:27:06 · last seen 2026-06-09 04:31:58