Ground fault detection device
AssigneeOMRON Corporation
InventorsAkihiko Sano, Kotaro Nakamura, Kenji Kobayashi, Kohei Nakagawa, Makoto Ide
Life of this patent
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Abstract
The disclosure is provided to improve the accuracy of a ground fault position detected from a power conditioning system. A ground fault position calculation part (41) calculates a ground fault position (Pg) by using a power supply voltage of a solar cell string (11), a ground fault current (Ig), and a ground potential of an input terminal (N) measured by a power conditioning system (12). The ground fault position calculation part (41) sets a lower limit value of the power supply voltage to be used.
Claims6
A ground fault detection device adapted for a solar power generation system comprising a solar cell string in which a plurality of solar cell modules are connected in series and a power conversion device for converting power supplied from the solar cell string and outputting the converted power to a system, the ground fault detection device comprising:
- a ground fault position specifying part for specifying a ground fault position by using an output voltage of the solar cell string, a ground fault current, and a ground potential measured by the power conversion device,
- wherein the ground fault position is between the kth solar cell module and (k+1)th solar cell module, where 1≤k≤n−1, n is the number of the solar cell modules, X=k/n, and X is a value indicating the ground fault position,
- wherein the ground fault position specifying part sets a lower limit value of the output voltage to be used.
A ground fault detection device adapted for a solar power generation system comprising a solar cell string in which a plurality of solar cell modules are connected in series and a power conversion device for converting power supplied from the solar cell string and outputting the converted power to a system, the ground fault detection device comprising:
- a ground fault position specifying part for specifying a ground fault position by using an output voltage of the solar cell string, a ground fault current, and a ground potential measured by the power conversion device,
- wherein the ground fault position specifying part outputs information on a range of an error of the ground fault position corresponding to the specified ground fault position.
A ground fault detection device adapted for a solar power generation system comprising a solar cell string in which a plurality of solar cell modules are connected in series and a power conversion device for converting power supplied from the solar cell string and outputting the converted power to a system, the ground fault detection device comprising:
- a ground fault position specifying part for specifying a ground fault position by using an output voltage of the solar cell string, a ground fault current, and a ground potential measured by the power conversion device,
- wherein the ground fault position is between the kth solar cell module and (k+1)th solar cell module, where 1≤k≤n−1, n is the number of the solar cell modules, X=k/n, and X is a value indicating the ground fault position,
- wherein the ground fault position specifying part obtains an I-V characteristic of the solar cell string from the power conversion device, creates corresponding information of the output voltage and the ground fault current for the ground fault position by using the obtained I-V characteristic, and specifies the ground fault position corresponding to the output voltage and the ground fault current obtained from the power conversion device based on the created corresponding information.
Dependencies are inferred from the claim text.