Monitoring system and method for detecting insulation state of photovoltaic battery strings

Abstract

The present invention mainly relates to a monitoring system and a monitoring method for detecting the insulation state of photovoltaic battery strings. A battery string is formed by connecting multiple photovoltaic cells in series. The total voltage on the battery string is provided to the inverter to perform direct current To the inverter of alternating current, the leakage current detection module is used to detect the ground leakage current induced by the photovoltaic cell due to the excitation of the common mode voltage existing between the bridge arm branches in the inverter. The system can detect the insulation state of each individual photovoltaic cell in the photovoltaic cell string in real time to the greatest extent, providing a basis for the safe operation of the photovoltaic power generation system.

Description

technical field [0001] The present invention mainly relates to the technical field of photovoltaic power generation. To be precise, it provides a detection system capable of monitoring the insulation state of photovoltaic battery strings in a topological structure containing photovoltaic cells, so as to detect in real time the maximum The insulation status of each individual photovoltaic cell provides a basis for the safe operation of the photovoltaic power generation system. Background technique [0002] With the non-renewability of traditional chemical energy such as oil, coal, natural gas, etc., and the negative environmental problems caused by chemical energy are becoming more and more serious, it is necessary to seek an inexhaustible and recurring renewable energy to replace limited resources. The traditional chemical energy with polluting environment has become an important proposition that urgently needs to be solved in the energy field. The development of science an...

AI Technical Summary

Problems solved by technology

Sampling like this to improve the reliability of the signal is only one aspect, but in the case where the photovoltaic cell and the carrier are applied at the same time, the voltage level of the photovoltaic cell itself will be greatly changed due to the influence of the ambient temperature and the intensity of light radiation. , so the distortion of the carrier signal on the power line itself and the battery’s output characteristics that are easy to fluctuate are mixed together, resulting in inaccurate real carrier signals that the receiver expects to capture and high bit error rates. The voltage superimposed on the strings is also subject to carrier interference, so the actual voltage on the entire string may not be within the expected range

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