Photovoltaic rapid shutdown and arc sensing system
Assigneedcbel Inc.
InventorsCedric SOMERS, Marc-André FORGET
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Abstract
The present disclosure provides a system, apparatus and method for providing rapid shutdown for photovoltaic power systems and provides a system, apparatus and method for providing arc sensing for photovoltaic power systems. An AC current can be put on the DC bus to control PV panel shutdown. Local mean decomposition can be used to sense arcing on the DC bus.
Claims26
An isolation switch device for a photovoltaic (PV) panel, the device comprising:
- an AC coupler and a bandpass filter connected in series between an input and an output of the device;
- a rectifier gate signal circuit connected to the AC coupler and providing a switch gate signal;
- and
- at least one normally open switch connected in parallel to the bandpass filter, a gate of said at least one normally open switch being connected to said switch gate signal.
A method for providing emergency de-energizing of a photovoltaic panel, the method comprising:
- injecting AC current over a DC bus of a PV panel array;
- isolating said AC current from said DC bus;
- and
- using said isolated AC current to cause a passive circuitry to allow flow of DC current from said PV panels over said DC bus, wherein an interruption of said AC provides said emergency de-energizing of said DC bus.
A method for arc detection in a photovoltaic system, the method comprising:
- collecting a raw signal by a sensor connected to a DC bus of said photovoltaic system;
- applying threshold Local Mean Decomposition (LMD) to extract a first set of peaks and valleys from said raw signal;
- finding a first set of envelopes using said first set of peaks and valleys;
- applying Windowed Local Mean Decomposition (LMD) to extract a second set of peaks and valleys;
- finding a second set of envelopes using said second set of peaks and valleys;
- comparing said first set of envelopes and said second set of envelopes;
- sending an output signal indicating arcing when said first set of envelopes and said second set of envelopes concurrently shows an arc in said system.
An arc-sensing circuit for use with a photovoltaic system comprising:
- a sensor connected to a DC bus of said photovoltaic system collecting raw signal from said DC bus;
- a control unit receiving said raw signal comprising:
- a processor;
- and
- a non-transitory computer-readable medium containing instructions that, when executed by the processor, causes the processor to perform:
- applying threshold Local Mean Decomposition (LMD) to extract a first set of peaks and valleys from said raw signal;
- finding a first set of envelopes using said first set of peaks and valleys;
- applying Windowed Local Mean Decomposition (LMD) to extract a second set of peaks and valleys;
- finding a second set of envelopes using said second set of peaks and valleys;
- comparing said first set of envelopes and said second set of envelopes;
- sending. an output signal indicating arcing when said first set of envelopes and said second set of envelopes concurrently shown an arc in said system.
Dependencies are inferred from the claim text.