An inverter output current passes from an inverter phase output, through a non-linear inverter side inductor, and into a line that connects through a grid side inductor to a grid phase. An inductance of the inverter side non-linear inductor is estimated, a current passing through the grid side inductor is estimated, and a current through the inverter side inductor is measured. An inverter feeding the inverter output is controlled using a weighted average of the estimated current through the grid side inductor and the inverter side inductor current measurement, applying a weighting using the estimated inductance.