System and method for connection of photovoltaic arrays in series and parallel arrangements

摘要

A system and method for selectively connecting photovoltaic (PV) arrays of a PV power system in series and parallel arrangements is disclosed. A DC-to-AC power inverter in the PV power system is electrically coupled to a plurality of PV arrays to receive a DC output therefrom and invert the DC output to an AC output, with the DC-to-AC power inverter including a DC link that receives the DC output from the plurality of PV arrays. A contactor arrangement is positioned between the plurality of PV arrays and the DC-to-AC power inverter, with the contactor arrangement including a plurality of contactors that are switchable between an on state and an off state to selectively connect the plurality of PV arrays to the DC-to-AC power inverter in a specified arrangement, so as to control a level of DC voltage received by the DC-to-AC power inverter from the plurality of PV arrays.

主权项

1. A photovoltaic (PV) power system comprising:
a plurality of PV arrays each configured to generate a direct current (DC) output from received solar irradiation; a DC-to-AC power inverter electrically coupled to the plurality of PV arrays to receive the DC output therefrom and invert the DC output to an AC output, the DC-to-AC power inverter including a DC link that receives the DC output from the plurality of PV arrays; a contactor arrangement positioned between the plurality of PV arrays and the DC-to-AC power inverter, the contactor arrangement including a plurality of contactors that are switchable between an on state and an off state to selectively connect the plurality of PV arrays to the DC-to-AC power inverter in a specified arrangement, so as to control a level of DC voltage received by the DC-to-AC power inverter from the plurality of PV arrays; a controller configured to control switching of the plurality of contactors between the on state and the off state for connecting the plurality of PV arrays to the DC-to-AC power inverter in the specified arrangement; and an arrangement of secondary contactors and resistors configured to load the plurality of PV arrays when the plurality of contactors are switched between the on state and the off state, so as to reduce a level of voltage on the DC link; wherein the controller is further configured to switch the secondary contactors when the plurality of contactors are switched between the on state and the off state to reduce the level of voltage on the DC link.