Cell-to-grid redundandt photovoltaic system

摘要

In an embodiment, a photovoltaic system includes multiple photovoltaic modules and a module-to-module bus. Each photovoltaic module defines a first end and a second end opposite the first end. Each photovoltaic module includes multiple photovoltaic cells and multiple converters. Energy generated by each photovoltaic cell has multiple paths through the photovoltaic cells to the second end. The converters are electrically coupled to the photovoltaic cells at the second end such that energy generated by each photovoltaic cell is receivable at any of the converters. The module-to-module bus is electrically coupled to each of the photovoltaic modules. The module-to-module bus has an output. Energy generated by each photovoltaic module is receivable at the output independent of any other of the photovoltaic modules.

主权项

1. A photovoltaic system comprising:
a plurality of photovoltaic modules, each photovoltaic module defining a first end and a second end opposite the first end, wherein each photovoltaic module comprises: a plurality of photovoltaic cells, wherein energy generated by each photovoltaic cell has multiple paths through the plurality of photovoltaic cells to the second end; and a plurality of converters electrically coupled to the plurality of photovoltaic cells at the second end such that energy generated by each photovoltaic cell is receivable at any of the plurality of converters; and a module-to-module bus electrically coupled to each of the plurality of photovoltaic modules, the module-to-module bus having an output, wherein energy generated by each photovoltaic module is receivable at the output independent of any other of the plurality of photovoltaic modules, wherein: each of the plurality of photovoltaic modules further comprises: a circuit card mechanically coupled to the second end; and a digital controller disposed on the circuit card; the plurality of converters are disposed on the circuit card; and the digital controller of each of the photovoltaic modules is configured to: trickle charge current onto the module-to-module bus when a voltage on the module-to-module bus is less than a minimum threshold to determine whether a capacitive element is attached to the module-to-module bus; in response to determining that the capacitive element is attached to the module-to-module bus, continue to trickle charge current onto the module-to-module bus until the voltage on the module-to-module bus rises above the minimum threshold; close a protection relay when the voltage on the module-to-module bus rises above the minimum threshold to ensure zero current switching, the protection relay being electrically coupled between the module-to-module bus and an output bus of the circuit card, the output bus being electrically coupled to outputs of each of the plurality of converters; operate the plurality of converters in a maximum current mode when the voltage on the module-to-module bus is between the minimum threshold and an intermediate threshold greater than the minimum threshold; operate the plurality of converters in a constant voltage mode when the voltage on the module-to-module bus is between the intermediate threshold and a maximum threshold greater than the minimum threshold; and open the protection relay when the voltage on the module-to-module bus rises above the maximum threshold or falls below the minimum threshold.