Harmonic mitigation optimization model by active resource across the distribution networks of multi-voltage level

Harmonic distortion seriously affects reliable operation of multi-voltage level distribution networks (DNs). Traditional mitigation methods based on active power filter generally offer poor economic efficiency. Photovoltaic (PV) inverters can generate controllable harmonic compensation currents, so this study proposes a harmonic mitigation optimization model. First, an upper-level model is constructed with objective of maximizing product of annual benefits for three participants, subject to constraints such as medium voltage PV (M-PV) capacity and medium voltage distribution network (MVDN) mitigation effectiveness; it effectively mitigates harmonic distortion in MVDN while optimizing annual benefits for all participants. Second, a lower-level model is constructed with objective of minimizing total distortion power emitted by all low voltage PVs (L-PVs), subject to constraints such as L-PV capacity and low voltage distribution network (LVDN) mitigation effectiveness, thereby ensuring that harmonics in LVDN don’t exceed limit. Then, harmonic current emitted by LVDN is used as interaction variable to coordinate the solution of upper-level and lower-level models, thereby reducing influence of harmonic coupling between different voltage levels on mitigation effect. Finally, a harmonics mitigation service pricing method is proposed, which adaptively adjusts unit prices based on degree of harmonic distortion in DNs, thereby promoting equity in annual benefits for all participants. Simulation results show that proposed model mitigates harmonic distortion in multi-voltage level DNs under various scenarios and achieves optimal annual benefits for each participant through model optimization, with the highest reaching $3240. Moreover, it provides an application scenario for PV inverters with harmonic mitigation capability and supports their functional upgrading.