Solar power module with safety features and related method of operation
AssigneeSunfield Semiconductor Inc.
InventorSteven Andrew Robbins
Life of this patent
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Abstract
A solar power module, and related method of operation, that protects the bypass diodes in the solar power module from overheating due to partial shading, and also protects firefighters and installer personnel from electrical shock hazard. The solar power module includes active bypass switches, and isolation switches that disconnect the PV cells from the bypass switches when all the bypass switches are closed concurrently, thereby allowing the PV cells to continue supplying power to the control circuitry. The isolation switches are also used to maintain the solar power module in a safe state during installation, or in case of fire.
Claims18
A solar power module, comprising:
- a pair of power output terminals;
- a plurality of bypass circuits serially connected between the two power output terminals, each bypass circuit comprising:
- a first terminal and a second terminal for said serial connection between the two power output terminals,
- a diode disposed between the first and second terminals,
- a first switch connected in parallel with the diode,
- a local controller for determining the polarity of the voltage across the diode and controlling the first switch, and
- a second switch disposed between the second terminal and a third terminal;
- a main controller for controlling the second switch in each bypass circuit and determining when all the first switches are closed concurrently;
- a plurality of photovoltaic segments for converting light into electricity, each photovoltaic segment having a plurality of photovoltaic cells connected in series, the photovoltaic segments serially coupled to at least one of the power output terminals and the third terminal in each bypass circuit;
- and
- a main power supply for receiving power from at least one of the photovoltaic segments and providing power to at least the bypass circuits.
A method for protecting bypass diodes in a solar power module from overheating, wherein the solar power module includes a plurality of bypass diodes serially connected between two power output terminals, each bypass diode having a bypass switch connected in parallel with it and an isolation switch coupling the bypass diode to an associated segment of photovoltaic cells, the method comprising steps of:
- closing a bypass switch in response to the associated bypass diode being forward biased;
- opening a bypass switch in response to the associated bypass diode being reverse biased;
- disconnecting the photovoltaic segments by opening all the isolation switches in response to all the bypass switches being closed concurrently;
- and
- reconnecting the photovoltaic segments by closing all the isolation switches in response to a reset signal.
Dependencies are inferred from the claim text.