Optimization model for harmonic mitigation based on PV-ESS collaboration in small distribution systems

Connecting a large number of distributed photovoltaics (PVs) and energy storage systems (ESSs) to a distribution network enables the mitigation of harmonic issues through grid-connected inverters with active topology. In this paper, we propose an optimization model for harmonic mitigation based on PV-ESS collaboration. The objective function is to minimize the total cost of harmonic mitigation, to ensure that the harmonic emission levels of all nodes in the network do not exceed the limit required by the IEEE standard. The constraint conditions include the fundamental frequency and harmonic power flow, voltage, mitigation performance, power for PV and ESS inverters, and cost constraints. The model is solved to obtain the amount of harmonic compensation currents and the unit price of the harmonic mitigation service of different inverters at different times. Finally, the validity of the proposed model is verified by the modified IEEE 13 node test feeder.