Grid-connected inverter system

Abstract

The invention provides a grid-connected inverter system. The grid-connected inverter system comprises a DC power supply, an inverter, an isolating transformer and a voltage control circuit; the DC power supply produces the first DC voltage; the inverter equipped with three AC voltage output ends is used to receive the first DV voltage and convert the same into the first AC voltage as well as output the first AC voltage through the AC voltage output ends; the isolating transformer is used to isolate the output voltage of the inverter to float opposite to earth; the voltage control circuit, comprising a grounding end, and a coupling end for grounding, is used to generate the second DV voltage and load the second DV voltage to at least one AC voltage output end of the inverter through the coupling end; the voltage control circuit is used to adjust the second DV voltage in order to adjust the voltage to earth of a positive electrode or a negative electrode of the DC power supply; the current output by the voltage control circuit is not greater than a preset current threshold. With the adoption of the grid-connected inverter system, the PID (Proportion Integration Differentiation) phenomenon of a DC power supply can be avoided, and the leakage protection effect is realized.

Description

technical field [0001] The invention relates to the field of voltage conversion, in particular to a grid-connected inverter system with potential-induced decay prevention and leakage protection. Background technique [0002] Potential Induced Degradation (PID) refers to the phenomenon that the high voltage to ground is applied to the battery panel to reduce its performance. The high voltage can be a positive voltage or a negative voltage, and whether the high voltage is a positive voltage or a negative voltage depends on the characteristics of the battery panel. For example, for a P-type photovoltaic cell panel, if the cell panel has a negative voltage to the ground, the performance of the P-type photovoltaic cell panel will be reduced. For an N-type photovoltaic cell panel, if the cell panel has a positive voltage to the ground, the performance of the N-type photovoltaic cell panel will be degraded. Taking the P-type photovoltaic panel as an example, in order to prevent t...

AI Technical Summary

Problems solved by technology

However, the resistance of the human body is generally very small. When the voltage value U of the output voltage of the DC power supply 110 is very high, the current passing through the human body is very large, exceeding the maximum safe current value that the human body can bear, thus causing an electric shock accident.

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