CIRCUIT FOR VOLTAGE LIMITATION IN A PHOTOVOLTAIC FIELD, PHOTOVOLTAIC FIELD, AND METHOD FOR VOLTAGE LIMITATION

摘要

A circuit for limiting the voltage of a photovoltaic string divided into a first section and a second section of a series circuit of solar modules, includes a first terminal for connection to a first end of the first section, a second terminal for connection to a first end of the second section and a third terminal for connection to a second end of the second section. The circuit also includes a bypass switch, which is connected at one end to the first terminal and at the other end to the third terminal and a disconnect switch, which is connected at one end to the first terminal and at the other end to the second terminal. The circuit has a controller for actuating the bypass switch and the disconnect switch, wherein the controller is configured to determine a first threshold value U_UL and a second, lower threshold value U_LL depending on a switch voltage U_OC dropped across the disconnect switch in an open state and taking into account the number of solar modules in the first section and in the second section.