A converter cell for a modular converter includes at least one power semiconductor switch for switching a cell current through the converter cell; a cell capacitor interconnected with the at least one power semiconductor switch, such that the cell capacitor is loadable by the cell current; a controller for switching the at least one power semiconductor switch, wherein the controller is supplyable with auxiliary power from the cell capacitor; and a photovoltaic cell for providing initial and/or further auxiliary power to the controller.