Photovoltaic high voltage induced attenuation effect (pid) elimination circuit and method thereof

Abstract

The invention discloses a photovoltaic PID (Potential Induced Degradation) elimination circuit which is mainly composed of an AC (Alternating Current) input power supply, a switching power supply, a comparison circuit and an output unit, wherein the AC power supply generates an isolated DC (Direct Current) high voltage via the switching power supply, while the switching power supply generates a comparison voltage; the comparison voltage is taken as a reference of a comparison circuit; when the PV voltage is higher than the comparison voltage, the comparison circuit disconnects a relay of the output unit, so as to close the output of a PID prevention unit; when the PV voltage is less than the comparison voltage, the comparison circuit closes the relay of the output unit, so as to open the output of the PID prevention unit. Meanwhile, the PV voltage is input to a blockade circuit, and when any PV voltage is higher than a blockade threshold, the whole circuit of the PID prevention unit is turned off.

Description

Technical field [0001] The invention relates to a circuit and method for eliminating the photovoltaic PID effect, and belongs to the field of photovoltaic power generation manufacturing. Background technique [0002] PV machines are equipped with PID prevention units inside or outside to prevent PV PID effects. They are widely used in PV inverters and PV power stations. At present, there are different opinions on the real cause of the PID effect of photovoltaic modules, but actual power station operation and research results show that PID phenomenon occurs when photovoltaic modules are under negative bias voltage, and the greater the negative bias voltage, the more obvious the PID phenomenon. The PID phenomenon is not obvious when the photovoltaic module is under a positive bias. Therefore, the PID effect can be prevented by grounding the negative pole of the photovoltaic cell module or applying a forward voltage to the ground at the output terminal of the cell module. At the s...

AI Technical Summary

Problems solved by technology

At present, there are different opinions on the real reason for the PID effect of photovoltaic modules, but the actual operation of the power station and the research results show that the PID phenomenon will occur when the photovoltaic module is under negative bias voltage, and the greater the negative bias voltage, the more obvious the PID phenomenon

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