MITIGATION OF ARC FLASH HAZARD IN PHOTOVOLTAIC POWER PLANTS

摘要

Arc flash mitigation devices are employed to protect personnel during maintenance of photovoltaic inverters. During normal operation, an alternating current (AC) output of a photovoltaic inverter is coupled to a low voltage winding of a step up transformer through a bus-bar (e.g., an electrically conductive interconnect), which has higher current rating than a fuse. During maintenance, the bus-bar is replaced with the fuse. The fuse may be employed in conjunction with a switch. The switch may be a disconnect switch that places the bus-bar in parallel with the fuse during normal operation, and decouples the bus-bar from the fuse during maintenance. The switch may also be a transfer switch that places either the bus-bar or the fuse in series with the AC output of the photovoltaic inverter and the low voltage winding of the step up transformer.

主权项

1. A system comprising:
a photovoltaic inverter that converts direct current (DC) generated by solar cells to alternating current (AC) that is provided at an AC output of the photovoltaic inverter; a step up transformer having a low voltage winding on a low voltage side and a high voltage winding on a high voltage side, the high voltage winding being coupled to a utility grid; and a switch-fuse link comprising a fuse and a switch, the switch comprising a first terminal and a second terminal, the second terminal being coupled to the low voltage winding, the switch further comprising a contact that connects the first terminal to the second terminal in a normal operation mode such that the AC generated by the photovoltaic inverter flows to the low voltage winding through the contact in the normal operation mode, the contact disconnects the first terminal from the second terminal in a maintenance mode such that the AC generated by the photovoltaic inverter flows to the low voltage winding through the fuse in the maintenance mode.