A resonant power converter comprising: a switching stage that includes a first set of switches and a second set of switches, wherein the first and second set of switches are operable to respectively produce a first and second voltage from a bulk voltage (Vbulk) on a voltage supply line and a bulk voltage return (Vbulk_return) on a voltage return line; a controller coupled with the switching stage, where the controller is operable to control switching of the first set of switches and the second set of switches to enable the output of the first voltage from the first set of switches and the second voltage from the second set of switches; a series resonant tank, SRT, comprising an inductor and a capacitor; and a transformer having a primary and a secondary winding; wherein the first and second voltages are applied to the series connected SRT and the transformer, wherein the transformer is operable to receive at the primary winding from the SRT a primary voltage representative of a combination of the first and second voltages (402, 404), where the controller is operable to control the primary voltage by variation of a relative phase difference between the first voltage and the second voltage; and wherein the controller is operable to determine a primary current by integration of a voltage drop across the inductor; wherein the controller is further operable to determine an average line current by integration of the primary current only during times when the first time variable voltage and the second time variable voltage have a relative phase difference such that the first time variable voltage and the second time variable voltage do not completely overlap, and wherein the controller is further configured to generate a drive signal to disable phase shifting of the relative phase of the first and second voltages, if an output representative of the average line current exceeds an output error signal provided by a limiter within the controller. a switching stage that includes a first set of switches and a second set of switches, wherein the first and second set of switches are operable to respectively produce a first and second voltage from a bulk voltage (Vbulk) on a voltage supply line and a bulk voltage return (Vbulk_return) on a voltage return line; a controller coupled with the switching stage, where the controller is operable to control switching of the first set of switches and the second set of switches to enable the output of the first voltage from the first set of switches and the second voltage from the second set of switches; a series resonant tank, SRT, comprising an inductor and a capacitor; and a transformer having a primary and a secondary winding; wherein the first and second voltages are applied to the series connected SRT and the transformer, wherein the transformer is operable to receive at the primary winding from the SRT a primary voltage representative of a combination of the first and second voltages (402, 404), where the controller is operable to control the primary voltage by variation of a relative phase difference between the first voltage and the second voltage; and wherein the controller is operable to determine a primary current by integration of a voltage drop across the inductor; wherein the controller is further operable to determine an average line current by integration of the primary current only during times when the first time variable voltage and the second time variable voltage have a relative phase difference such that the first time variable voltage and the second time variable voltage do not completely overlap, and wherein the controller is further configured to generate a drive signal to disable phase shifting of the relative phase of the first and second voltages, if an output representative of the average line current exceeds an output error signal provided by a limiter within the controller.